A handbook for planners in developing countries

TD/B/C.4/175fRe\. 1

UNITED NATIONS CONFERENCE ON TRADE AND DEVELOPMENT

Port developmentA handbook for planners in developing countries

Second editionrevised and expanded

UNITED NATIONS

UNITED NATIONS CONFERENCE ON TRADE AND DEVELOPMENT

Geneva

Port development

A handbook for planners in developing countries

Prepared by the secretariat of UNCTA D

Second editionrevised and expanded

UNITED NATIONS

New York, 1985

-

NOTE

United Nations documents are designated by symbols composed of capitalletters combined with figures. Mention of such a symbol indicates a reference to aUnited Nations document.

The designations employed and the presentation of the material in this publi-cation do not imply the expression of any opinion whatsoever on the part of theUnited Nations Secretariat concerning the legal status of any country or territory orof its authorities, or concerning the delimitation of its frontiers.

References to dollars ($) are to United States dollars.

UNITED NATIONS PUBLICATION

I SalesNo. E.84.II.D.l I

023caP

lSBN92-1-112160-4

ACKNOWLEDGEMENTS

The UNCTAD secretariat wishes to thank the many port authorities, planningorganizations, economic and civil engineering consultants and other bodies whichco-operated in this project by describing their methods of planning and by fur-nishing the secretariat with information.

In particular, the secretariat has been actively assisted in preparing the hand-book by Mr. B. Nagorski and Mr. S. M. Maroof and by the consulting firms ofRendel, Palmer and Tritton, and Sir William Halcrow and Partners.

Valuable information has also been supplied by Bremerhaven LagerhausGesellschaft, Manalytics Incorporated, the National Ports Council of the UnitedKingdom, the Overseas Coastal Area Development Institute of Japan, Peat, Mar-wick, Mitchell and Company, the Planning and Research Section of Los AngelesHarbour Department and Sea-Land Service Incorporated.

The UNCTAD secretariat would also like to express special thanks to theGovernments of Denmark, Finland, the Netherlands, Norway and Sweden whosegenerosity in providing a grant made it possible to undertake this work.

The UNCTAD secretariat is pleased to state that Mr. A. J. Carmichael, PortsAdviser in the Transportation Department of the World Bank, and other Bankstaff members working on international port development have welcomed thepublication of this handbook and recommended its use as a reference manual.

The valuable comments and suggestions made by the World Bank staff aremost gratefully acknowledged. While the opinions expressed in the handbook arethose of the UNCTAD secretariat, the individual members of the World Bank staffwho have read the text have agreed with the secretariat’s view that port develop-ment based on the methods recommended is likely to be economically and technic-ally sound.

The detailed suggestions made by the Special Committee of the PermanentInternational Association of Navigation Congresses (PIANC), set up to examinethe first edition of this handbook under the chairmanship of Mr. P. Bastard, aregratefully acknowledged. The comments and additional facts provided by thisCommittee have led to a number of improvements. The UNCTAD secretariat ispleased to note that the PIANC Special Committee considers that the publication isa valuable contribution to port planning in developing countries.

In addition, the UNCTAD secretariat would like to thank Mr. G. Sub-rahmanyam for his contribution on service facilities for ships.

Finally, the UNCTAD secretariat would like to mention the co-operationreceived from the International Maritime Organization and the Food and Agricul-ture Organization of the United Nations for comments and suggestions on improve-ments for the second edition of this handbook.

i i i

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CONTENTS

Page

Abbreviations . . . . ..__.................................._......_...._._... xiv

INTR~DLJCI-ION _.._,..._,....._,...._.....__............._....__.

Part OneChapter

I. THEMANAGEMENTOF~~RTDWEL~PMENT ......................

A. The need for a national ports plan. . . . . . . . . . . . . . . . . . . . . . . . . . .B. The national ports authority . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C. Portdevelopment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D. Long-term planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .E. The sequence of investment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .F .G .

Maintaining capacity during engineering work . . . . . . . . . . . . . . . . .Project planning: the feasibility study . . . . . . . . . . . . . . . . . . . . . . . .

H. Theanalysesneeded . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .I . Ancillary services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .J. Development of the port organization . . . . . . . . . . . . . . . . . . . . . . .K. Project control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .L. Useofconsultants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .I: 1M . UNCTAD assistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .N. Port development finance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0 .P .

Contents of an investment proposal . . . . . . . . . . . . . . . . . . . . . . . . .Procedure for implementation of port projects . . . . . . . . . . . . . . . . .1. The implementation sequence . . . . . . . . . . . . . . . . . . . . . . . . . . .2. Tendering policy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3. Tender documents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4. Bid evaluation and award of contract . . . . . . . . . . . . . . . . . . . : : :5. Supervision of work. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6. Design and construct tenders (turnkey contracts). . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . .Q.

7. Tenders for dredging and reclamationParticipation of project planners . . . . . . . . . . . . . . . . . . . . . . . . . . . .

R. Project proposals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Annex: Standard layout of a port project proposal . . . . . . . . . . . . . . . . . . .

II. PLANNINGPRINCIPLES ....................................Port planning objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . : 1:A.

B.C.D.E.F .G.H.I.J .K.L.M.

2P .Q.

The investment plan . . . . . . . . . . . . . . . . . . . . . . . .Terminal design principles . . . . . . . . . . . . . . . . . . .The problem of planning berthing capacity . . . . . . .Cost considerations . . . . . . . . . . . . . . . . . . . . . . . .Berth occupancy. . . . . . . . . . . . . . . . . . . . . . . . . . .Waiting-time/service-time ratio . . . . . . . . . . . . . . .Planning for variations in traffic . . . . . . . . . . . . . . .Co-ordinated contingency planning . . . . . . . . . . . .The economic optimum . . . . . . . . . . . . . . . . . . . . .Scheduled traffic . . . . . . . . . . . . . . . . . . . . . . . . . .Seasonal variations. . . . . . . . . . . . . . . . . . . . . . . . .Capacity and traffic specialization. . . . . . . . . . . . . .Flexibility and technical change . . . . . . . . . . . . . . .Principles of investment appraisal . . . . . . . . . . . . . .Financial analysis . . . . . . . . . . . . . . . . . . . . . . . . . .Economic appraisal . . . . . . . . . . . . . . . . . . . . . . . .

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Y

Poragrophs

i-xiv

1-97

l-89-14

15-1920-2526-2829-3132-4041-45

4647-5152-56

5758

59-6263

64-9364-6667-7273-7980-8182-8687-9192-9394-9596-97

98-196 2798-102 27

103-107 27108-109 28110-111 28112-116 28117-119 29

120 30121-128 30129-135 3 1136-142 32143-144 32145-149 33150-154 33155-160 34161-162 35163-170 35

171 36

1

5

55789

1 21 21 6171 718182020212121222324242525252526

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Chapter

R.S .T .U.V.W .X.Y.

costs . . . . . . . . . . . . . . . . . . . . .B e n e f i t sD i s c o u n t i n gThe congestion cost pitfallSummary methods of evaluation,The four investment decisions.Joint proposals .Examination of uncertainty

172-173174

175-176177

178-183184-189190-192193-196

III . TRAFFICFORECAS~NG .................................................A. Forecasting principles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B. Scenario writing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C. Control statistics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D. Combining the uncertainty in separate factors . . . . . . . . . . . . . . . . .E. The forecasting procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .F .G .

Forecasting cargoes carried by roiro ships . . . . . . . . . . . . . . , . . . . . .The market forecast . . . . . . . . . . . . . . . . . . . . . . . . . . . . . a . . . . . . .

H. Rate of growth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .I . Events . . . . . . . . ..........i...i . . . . . . . . . . . . . . . . . . . . . . . .J. Effect of the port’s own policies . . . . . . . . . . . . . . . . . . . . . . . . . . . .K. Trend forecasting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .L. Seasonal variations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .M . General cargo traffic and GNP trends. . . . . . . . . . . . . . . . . . . . . . . .N. Container traffic forecasts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0 . Hinterland changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .P . Government traffic. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Q. Trans-shipment traffic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .R. Technological changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .S . Shiploads and number of ship calls . . . . . . . . . . . . . . . . . . . . . . . . . .T . Shipsize. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .U. Evaluation of forecasts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Paragraphs

IV. PRODUCTIVITYANDOPERATIONALPLANNING .A. Pitfalls in estimating productivity . . . . . . . .B. Rated and effective productivity. . . . . . . . .C. Matching of operations. . . . . . . . . . . . . . . .D. Appropriate technology . . . . . . . . . . . . . . .E. Productivity increases. . . . . . . . . . . . . . . . .F . Offsetting effects . . . . . . . . . . . . . . . . . . . .G. Productivity targets . . . . . . . . . . . . . . . . . .H. Operational planning . . . . . . . . . . . . . . . . .

V. MASTERPLANNINGANDPORTZONING ..........A. Port location. . . . . . . . . . . . . . . . . . . . . . . . . .B. The master planning approach . . . . . . . . . . . .C. Classes of port . . . . . . . . . . . . . . . . . . . . . . . .D. Harbour configuration . . . . . . . . . . . . . . . . . .E. The industrial port . . . . . . . . . . . . . . . . . . . . .F . Free zones . . . . . . . . . . . . . . . . . . . . . . . . . . .G. Reclamation. . . . . . . . . . . . . . . . . . . . . . . . . .H. Rationalizing port land-use. . . . . . . . . . . . . . .I. Z o n i n g . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .J . Increasing revenue from large port expansionsAnnex: Master plan case study: Los Angeles. . . . . .

VI. NAUTICALASPECTSOFPORTPLANNING .........A. General considerations. . . . . . . . . . . . . . . . . .B. Ship manoeuvrability . . . . . . . . . . . . . . . . . . .C. Effects of environmental conditions . . . . . . . .D. Consequences for port planning . . . . . . . . . . .

1. Depth of approach channels. . . . . . . . . . . .2. Channel width . . . . . . . . . . . . . . . . . . . . . .3. Channel layout . . . . . . . . . . . . . . . . . . . . .4. Principal manoeuvring areas within the port

.

197-258197-200201-203204-206

207208-21421.5-218219-221222-224225-226227-229230-231

232233-235236-240

241242

243-245246-248249-254255-256

257

259-2862 5 9 - 2 6 42 6 5 - 2 6 6267-2712 7 2 - 2 7 42 7 5 - 2 7 9

280281-2832 8 4 - 2 8 6

53535354545556

:6”

287-334287-290291-294295-297298-301302-307308-315316-321322-324325-333

334.

585858596061

:;63

2:65

335-372 73335-343 73344-351 74352-357 75358-372 75359-361 75362-365 76

366 76367-372 77

P a g e

3636363737373838

40404040414 143444646464747484849494949505 151

vi

Chopler Paragraphs

VII. CIVIL ENGINEERING ASPENS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 373-534A. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B. Field investigations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

~~~3~~~

1. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3772. Hydrographic and topographic surveys . . . . . . . . . . . . . . . . . . . .3. Meteorological survey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

~~~:S~~

4. Oceanographic survey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5. Coastal hydraulic survey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

~~~;~~~

6. Geotechnical survey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7. Hydraulic model studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

~~~3~~~

C. Water area requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1. Ship draught rule of thumb . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

46)o~:~~~

2. Approach channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3. Lay-bys and turning areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

~:~:~~~

4. Tidal harbours and locked basins . . . . . . . . . . . . . . . . . . . . . . . . . 435-4395. Navigational aids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6. Economic factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

44yi-4$

D. Dredging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 447-4621. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 447-449

2. Site investigation data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3. Types of dredger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

45:;$51

4. Dredger operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 453-4575. Reclamation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 458-4606. Economic factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 461-462

E. Breakwaters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 463-4821. Design data required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 463-4672. Alternative types of breakwater. . . . . . . . . . . . . . . . . . . . . . . . . .3. Design procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

~~~:~~~

4. Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 477-4795. Economic factors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 480-482

F . Quays and jetties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 483-5291. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 483-4862. Quaywalls3. Jetties and dolphins

............................................................................. ziK&ii

4. Special types of berth, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5. Berth fittings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$SS:~~

6. Fendering of berths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .G. Engineering cost estimates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

:20:!.~~

VIII. ENVIRONMENTAL AND SAETY ASPENS. . . . . . . . . . . . . . . . . . . . . . . . . . 535-571A. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 535-536B. Environmental aspects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 537-552

1. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 537-5402. Impact surveys. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 541-5443. Operational hazards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 545-5464. Port industrial areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 547-552

C. Dangerousgoods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 553-5711. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 553-5552. Inventory of risks, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 556-5593. Preventive measures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 560-5684. Provisions for accidents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 569-5705. Cost considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 571

IX. INLAND TRANSPORT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 572-606A. The system as a whole. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 572-577B. Trading practices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 578-580C. Inland transport capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D. Vehicle access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

:;k:Kl;;

E. Through-transport systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 593-596F . Technical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 597-598G. Information systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Port access gates, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59%$00

Loachngbays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 602-603

vii

Page

7878787878787980808 18 18182848485858 5858 5868686888888888990909191919495959798

101101101101101102102102102103103104104

105105105106107108109109110110

ChapterJ .K.

Platform levellers .Paragraph Page

Industrial doors . .604605

L. Railloadingbays .,..._,,....,....,...,,,... :::::::::::: 606

1 1 11 1 11 1 1

X . M A I N T E N A N C E A N D E Q U I P M E N T P O L I C Y ...............A. Generalconsiderations..

607-636. . . . . . . . . . . . . . . . . . . . . . .

B.C.

The central workshop.:::::::::: 607-614

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 615-616

D.Guidelines for estimating maintenance costs for mobile equipment 1’Spare parts provision

617

E.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Maintenance manuals.618-619

F . Training. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 620

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .G .H.

Defect reporting. . . . . . . . . . . . . . . . . . . . . . . . . . . : : : : : : : : : : : : :621

Maintenance of structures622

. . . . . . . . . . . . . . . . . . .I . Equipmentreplacement.. . . . . . . . . . . . . . . . . . . .J . Guidelines for economic life

:::::::::::::623-632633-635

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 636

Part Two

I. TERMINALPLANNING~~N~IDERA~~NsA.

..........................The changing pattern

l-23. . . . . . . . . . . . . . . . . . . . . . . . . . . .

B.C.

Studyofexistingportfacilitiesl-2

. . . . . . . . . . . . . . . . . . . . .

D.General cargo berth group

1: 1:: ::I 3-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Bulk cargo terminals.7-11

. . . . . . . . . . . . . . . . . . . . . . . . .E. Terminal capacity calculations . . . . . . . . . . . . . . . . . . : : : : : : : : : : :

12-1415-23

II. THEBREAK-BULKBERTHGROUP ..............A. Needforbreak-bulkberths

24-104. . . . . . . . . . . . . . .

B. Theberthgroup:::::::::::::::::24

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C.D.

Economyofscaleandberthoccupancy25-26

. . . . . . . . . . . . . .Quays or moorings for general cargo

.:::::::: 27-30

E.. . . . . . . . . . . . . . . . . . . . . . . .

How many berths are there now?31-34

. . . . . . . . . . . . . . . .F . Berthcapacitycalculations

35-39. . . . . . . . . . . . . . . . . . . . . : : : : : : : : : : :

G .40-41

Number of berths required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42-49H. Berth length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50-52I. Sensitivity studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53-55J . Dimensioning of storage areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56-65K. Transit areas. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66-68L. Transit shed design. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69-74M . Warehousing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75-76N. Layout for deep-sea berths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77-800 . Layout for coastal or island berth . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 1P . Manpower planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82-87Q. Quayside rail track . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88R. Quaycranes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89-91S . Provision of mobile equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92-100T . Cargo-handling attachments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101-102U. Elevators and conveyors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103-104

III . CONTAINERTERMINALS ....................................A. Container ship development.

105-158. . . . . . . . . . . . . . . . . . . . . . . . . . . . : :

B.105-111

Planning and organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112C. Productivity........................................::: 113-119D. Container handling systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120-125

1. Trailer storage system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1212. Fork-lift truck system. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1223. Straddle-carrier system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1234. Gantry-crane system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1245. Mixed systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125

E. Area requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . : : :F .

126-137Berth occupancy at specialised unit terminals . . . . . . . . . . . . . . . . . . 138-144

G. Information systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .H.

145-146Schedule-day agreements . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . : : : :147-149

Container feeder services 150-153J . Types of container handling equipment . . . . . . . . . . . . . . . . . . . . . . 154-158

viii

112112113113113114114114114115116

1191191191201 2 11 2 1

1231 2 31 2 31231241241251 2 5130130 --1 3 11331 3 31341341361361381381 3 8139139

1 4 11 4 11421 4 21441441441441461461461501 5 31 5 3153154

VII. D R Y B U L K C A R G O T E R M I N A L S ................................. 218-397

A. Introduction, 218-219. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B. Main characteristics of a major bulk cargo terminal . . . . . . . . . . . . 220-224C. Bulk carriers, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225-230D. Bulk handling equipment performance specifications . . . . . . . . . . . . 231-237E. Ship loading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .F . Types of ship-loaders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

~:~!~~I

G. Shipunloading 248-2711. Grabs . . .

.......................................................................................................................

2. Pneumatic systems~4%~~~

3. Vertical conveyors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4. Bucket elevators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

~~~1~~

5. Slurry system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6. Self-discharging vessels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

262:;;:

H. Horizontal transport. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .I . Weighing and sampling, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

~7’::~C

J. Stackers and reclaimers 289-305. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .K. Storage .L. .....................................................................................Vehicle reception

ZX$:&:~

M . Stand-by facilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320-321N. Environmental considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0 . Planning tasks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

~~~:~~~

P . Major bulk commodities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1. Ironore . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

~~~:~~~

2. Grain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 366-3713. Coal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 372-3804. Phosphates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5. Bauxite/alumina . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

:;:XU;zi

Q . Multi-purpose bulk cargo terminals . . . . . . . . . . . . . . . . . . . . . . . . 394-397

Annex: Bulk stockpile planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

VIII. LIQUIDBULKCARGOTERMINALS ............................... 398-435A. Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 398-400B. Crude oil and oil products. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C. Liquefied natural gas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

tCl::3f:

D. Vegetable oils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 416-421E. Molasses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .F . Rubberlatex . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

tZ12ig

G. Liquefied ammonia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .H. Phosphoric acid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

t~~:N~:

Chapter Plmgraphs

Iv. THEMULTI-PURPOSEGENERALCARGOTERMINAL ..................A. Economics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

;;;:;;

B. LayoutC. Equipment

.....................................................................................................................................

16:6:67

D. Management 169-172

V. TERMINALREQUIREMENTSFORROLL-ON/ROLL-OFFTRAFFIC .......... 173-201A . The role of roiro services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173-181B. Roiro demand forecasting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182-183C. Berth requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D. Terminal area requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

:~~1~~~

E. Roiro terminal equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199-201

VI. TERMINALREQUIREMENTSFORBARGE-CARRYINGVESSELS .......... 202-217

A. Barge-carrier systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202-207B. Barge-carrier handling requirements . . . . . . . . . . . . . . . . . . . . . . . .C. Barge-handling requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

$%l:l

Page155155155156157

1591.59160160162164

165165165165

1681681681681691701711721721731751751761761761771771801 8 1182183183192192192193195196196197

198198198200200201201202202

IX. MISCELLANEOUSFACILITIES .................................. 436-481 203A. Service craft . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 436-439 203B. Service facilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 440-452 203

ix

I.

II.

III .

1.2 .3 .4 .5 .6 .7 .8 .9 .

1 0 .1 1 .1 2 .1 3 .1 4 .1 5 .1 6 .

A.l.A.2.A.3.A.4.

A.5.

C. Passenger terminalsParagraphs Page

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 453-457 204D. Fishing ports. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 458-467 204E. Marinas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 468-469 205F . Dry docks and floating docks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 470-476 205G. New typesof marine transport vessels. . . . . . . . . . . . . . . . . . . . . . . . 477-481 206

ANNEXES

GENERALINFORMATION ......... .........A. Conversion factors . . . . . . . . . . .........

1. Length. . . . . . . . . . . . . . . . . .........2. Area . . . . . . . . . . . . . . . . . . .........3. Volume . . . . . . . . . . . . . . . . .........4. Capacity . . . . . . . . . . . . . . . .........5. Weight. . . . . . . . . . . . . . . . . .........6. Unitization . . . . . . . . . . . . . .........7. Grains . . . . . . . . . . . . . . . . . .........8. Oils . . . . . . . . . . . . . . . . . . . .........

B. Commodity characteristics . . . . .........C. D i s c o u n t f a c t o r s . .........D. Amortization factors . . . . . . . . .........E. Random number table . . . . . . . .........

MATHEMATICALTECHNIQUES. ............................A. Monte Carlo risk analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B. Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C. Combination of traffic class uncertainties . . . . . . . . . . . . . . . . .D.E.

Statistics of ship arrival, service distributions and waiting timeMathematical basis for planning charts . . . . . . . . . . . . . . . . . . .

F . Economic life calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

......

......

......

......

......

......

......

......

......

......

......

......

......

......

216216217218219220224

I

207. 207

207207207207207207208208208208208208

THEPORTDEVELOPMENTREFERENCELIBRARY............................ 225

LIST OF FIGURES AND TABLES

TABLESINPARTONE

Procedure for national ports master planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Procedure for individual port master planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Procedure for port project planningCheck-list of ancillary port services

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Check-list of organizational elements needed in a port administration. : : : : : : :The forecasting procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Typical traffic forecast layout for various years . . . . . . . . . . . . . . . . . . . . . . : : : : : : :Typical traffic forecast layout by route-year 1985 . . . . . . . . . . . . . . . . . . . . . . . . . .Maximum weight per TEU as a function of stowage factor . . . . . . . . . . . . . . . . . . . .Productivity check-list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Numberofworkersperacrebytypeofindustry.. . . . . . . . . . . . . . . . . . . . :::::::List of site investigations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Comparison of steel and concrete piles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Maintenance costs for mobile equipment: values adopted for estimating purposesMaintenance costs for structural elements: values adopted for estimating purposes,Average length of economic life for port facilities and equipment . . . . . .

. . . . . . . . . .

9101 4171 741444548

2;7995

1 1 3114115

T o t a l c a r g o c o m m o d i t y f l o w p r o j e c t i o n s , 1 9 8 0 - 2 0 0 0Intensity of land utilization for cargo handling and storage, 1973.

68

Projected land needs, 1980-2000 .68

Summary of land utilization for purposes other than cargo handling and storage, by70

planningarea,l973...............................................Planned changes in areas for handling different types of cargo 1 : :

7072

x

TABLES IN PART Two

1 . Physical characteristics of container ships . . . . . . . . . . . . . . . . . . . . . . . . .2 . Principal dimensions of typical steel containers. . . . . . . . . . . . . . . . . . . . .3 . Typical container feeder ships. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 . Handling equipment required for multi-purpose general cargo terminals5 . Principal barge-carrier dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 . Barge dimensions, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 . Transport fleet planning for a single commodity . . . . . . . . . . . . . . . . . . . .8 . Transport fleet planning for multiple commodities . . . . . . . . . . . . . . . . . .9 . Check-list of questions for planning dry bulk terminals . . . . . . . . . . . . . . .

1 0 . Sizes of ship employed in the grain trade. . . . . . . . . . . . . . . . . . . . . . . . . .

TABLES IN ANNEXES

1 . Selected commodity characteristics for port planning . . . . . . . . . . . . . . . . . . . . .II. Discount factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

III . Amortization factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .IV. A table of 1,400 random units. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .V. Terminal cargo traffic forecast and probability . . . . . . . . . . . . . . . . . . . . . . . . . .

VI. Combinations of traffic forecasts and probabilities . . . . . . . . . . . . . . . . . . . . . . .VII. Summary of analysis of port data collected for congestion surcharge study

VIII. Waiting-time factor. Average waiting time of ships in the queue M/&In . . . . . . .IX. Average waiting time of ships in the queue EZIE21n. . . . . . . . . . . . . . . . . . . . . . .X. Example of economic life or replacement period calculation for a fork-lift truck

FIGURES IN PART ONE

1 . National port planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 . The planning sequence - I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 . A typical port planning sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 . The planning sequence - II, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 . Information needed for port development project . . . . . . . . . . . . . . . . .6 . Typical port organizational structure . . . . . . . . . . . . . . . . . . . . . . . . . . .7 . Port Island, Kobe, Japan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B . The overall procedure for port development. . . . . . . . . . . . . . . . . . . . . .9 . A typical tendering sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1 0 . Variation of port costs with increasing traffic . . . . . . . . . . . . . . . . . . . . .1 1 . Variation of the cost of ship’s time in port with increasing traffic . . . . . . .1 2 . Variation of total costs in port with increasing traffic. . . . . . . . . . . . . . . .1 3 . The pay-back period approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 4 . Application of funds to a number of competing projects . . . . . . . . . . . . .1 5 . The forecasting procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 6 . Simplified forecasting procedure for minor investments . . . . . . . . . . . . .1 7 . Separating a seasonal variation from a trend . . . . . . . . . . . . . . . . . . . . . .1 8 . The effect of feeder services on quayside activity . . . . . . . . . . . . . . . . . .1 9 . Combined capacity of ship cargo-handling system and transfer system20. Diagrammatic representation of a highway of varying widths . . . . . . . . .21. Artificial harbour configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 2 . Natural harbour configurations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23:. Port layout to maximize quay wall length . . . . . . . . . . . . . . . . . . . . . . . .24. Port layout to maximize operational land area . . . . . . . . . . . . . . . . . . . .2 5 . Modern pier layouts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26. Allocation of traffic to port zones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 7 . Definition of under-keel clearances . . . . . . . . . . . . . . . . . . . . . . . . . . . .28. Effect of littoral drift on coastal harbour. . . . . . . . . . . . . . . . . . . . . . . . .29. Typical width dimensions of channel. . . . . . . . . . . . . . . . . . . . . . . . . . . .3 0 . Example of a locked basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 1 . Five types of dredger in common use . . . . . . . . . . . . . . . . . . . . . . . . . . .3 2 . Examples of breakwaters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 3 . Examples of various artificial armour units . . . . . . . . . . . . . . . . . . . . . . .3 4 . Examples of quay wall construction . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 5 . Typical jetty for large oil tankers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

xi

Pllge

1411411541561661671891 9 1191193

209213213214218219219

. 2212 2 2

2 2 4

61 1131 51 61 92021222929293738424247505455596060616164758083848789909296

36.37.38.39.40.41.42.43.44.45.

A.l.A.2.A.3.A.4.A.5.A.6.

1 .2 .3 .4 .5 .6 .7 .8 .9 .

1 0 .11.1 2 .1 3 .1 4 .1 5 .1 6 .1 7 .1 8 .1 9 .20.21.22.23.24.25.26.27.28.29.30.31.3 2 .33.34.35.36.3 7 .3 8 .3 9 .40.41.

Water area requirements for single-buoy mooring . . . . . . . . . . . . . . . . . . . . . . . . . .Examples of fendering systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Theimportflow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Inland transportation network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . : : : : :The effect of introducing intermediate depots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Combined road-rail hinterland distribution network . . . . . . . . . . . . . . . . . . . . . . .Limitation on vehicle access to quay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . : :Comparison of locating container freight station within port area or outside it . . . . .Loading bay configuration for road transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Typical rail loading platform. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Page

9799

1 0 51061071071081091101 1 1

Past and future development of the port of Los Angeles, 1872-1990 .Port of Los Angeles, land use 1975 . . . . .Tonnage projections for port of Los Angeles . . . : :

666769

Comparison of commodity flow projections and land acreage needs . 69Alternative landfill proposals . . . .PortofLosAngeles,masterplan1990 . . . . .::I

707 1

FIGURESINPARTTWO

Phases of transition of a growing port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Estimating the existing number of berths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Break-bulk general cargo terminal, planning chart I: berth requirements . . . . . . . . .Break-bulk general cargo terminal, planning chart II: ship cost. . . . . . . . . . . . . . . . .Example of use of planning chart I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Example of use of planning chart II . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . :Berth length correction factor for break-bulk general cargo terminal planning . . . . .Break-bulk general cargo terminal, planning chart III: storage area requirements. ..Variation in storage demand. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Types of transit shed construction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Typical modern three-berth break-bulk zone (480 X 250 metres) . . . . . . . . . . . . . . .Small modern coastal or island berth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Gang-pool size correction factor for break-bulk general cargo terminal planning . . .Mobile dockside tower crane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Examples of fork-lift truck attachments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Dependency tree for container terminal planning . . . . . . . . . . . . . . . . . . . . . . . . . . .Example of trailer storage container terminal layout. . . . . . . . . . . . . . . . . . . . . . . . .Example of straddle-carrier container terminal layout . . . . . . . . . . . . . . . . . . . . . . .Example of gantry-crane container terminal layout. . . . . . . . . . . . . . . . . . . . . . . . . .Container terminal, planning chart I: container park area. . . . . . . . . . . . . . . . . . . . .Container terminal, planning chart II: container freight station (CFS) area. . . . . . . .Cross-section of container freight station . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Container terminal, planning chart III: berth-day requirement . . . . . . . . . . . . . . : : :Container terminal, planning chart IV: ship cost. . . . . . . . . . . . . . . . . . . . . . . . . . . .Typical gantry-cranes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Proposed layout for a two-berth multi-purpose general cargo terminal . . . . . . . . . . .First phase of the multi-purpose terminal, alternative 1. . . . . . . . . . . . . . . . . . . .First phase of the multi-purpose terminal, alternative 2. . . . . . . . . . . . . . . . . . . . : : :Alternative layouts for a ro/ro quay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Preferred layout of a single ro/ro corner berth. . . . . . . . . . . . . . . . . . . . . . . . . . .Example of slewing ramp for ro/ro service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . : : :Example of adjustable bridge ramp for ro/ro service . . . . . . . . . . . . . . . . . . . . . . . . .Ro/ro terminal planning chart: vehicle storage area . . . . . . . . . . . . . . . . . . . . . . . . .LASH facilities at Bremerhaven . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Principal dimensions of dry bulk cargo carriers . . . . . . . . . . . . . . . . . . . . . . . . . : : : :Operating draughts for different load factors against dwt for dry bulk cargo carriersExample of travelling ship-loader with material from high-level conveyor. . . . . . . . .Radial and linear loader comparison. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Travelling overhead trolley unloader grabbing crane . . . . . . . . . . . . . . . . . . . . . . . .Revolving grabbing crane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Portable pneumatic handling equipment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . : :

1201 2 51261271 2 81291 3 11321321341 3 51 3 71371 3 81401 4 31 4 51 4 51461481491501 5 11521541561571581601 6 11621621631671691701 7 1172173174174

42.43.44.4.5.46.47.48.49.50.51.

52.53.54.55.56.57.58.59.60.

I.II.

III.IV.

V.

Chainconveyorunloader . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Principle of belt loop or tripper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Arrangement of stacker for feeding stockpiles . . . . . . . . . . . . . . . . . . . . . . . . . . . .Typical stacker/reclaimer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Underground reclaim with gravity feed to belt conveyor. . . . . . . . . . . . . . . . . . . . .Export port showing arrangement of wind-row stockpiles . . . . . . . . . . . . . . . . . . . .Dry bulk cargo terminal, planning chart I: berth time . . . . . . . . . . . . . . . . . . . . . . .Dry bulk cargo terminal, planning chart II: ship cost. . . . . . . . . . . . . . . . . . . . . . . .Typical variation in dry bulk cargo terminal inventory level . . . . . . . . . . . . . . . . . .Guidelines for export stockpile dimensioning as a function of annual throughputand average shipload . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Stockpile layouts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Dry bulk cargo terminal, planning chart III: stockpile dimensioning . . . . . . . . . . . .Iron-ore loading berths: maximum acceptable ship sizes . . . . . . . . . . . . . . . . . . . . .Material flow in ore export port at Nouadhibou, Mauritania . . . . . . . . . . . . . . . . . .Plan of typical grain terminal at Marseilles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Example of multi-purpose oil-bulk-ore pier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Typical jetty arrangement for tanker terminal. . . . . . . . . . . . . . . . . . . . . . . . . . .Principal dimensions of very large crude carriers. . . . . . . . . . . . . . . . . . . . . . . . . . .Typical vegetable oil installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

FIGURES IN ANNEXES

Cumulative probability distribution for Monte Carlo numerical exampleComparison of total tonnage distribution for correlated and uncorrelated casesArrival pattern of break-bulk vessels with an average of one ship every two daysComparison of Erlang 1 and Erlang 2 distributions for an average vessel service timeoffivedays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Graph showing relationship between average ship waiting time and berth utilization

Page

175178178178180182185186188

188189190192192194196199199200

217218220

222223

x i i i

ABBREVIATIONS

Names of bodies and organizations

American Petroleum InstituteFood and Agriculture Organization of the United NationsFCddration internationale des ingtnieurs-conseils

(International Federation of Consulting Engineers)International Association of Ports and HarboursInternational Cargo Handling Co-ordination AssociationInternational Development AssociationInternational Maritime OrganizationInternational Organization for StandardizationPermanent International Association of Navigation CongressesUnited Nations Conference on Trade and DevelopmentUnited Nations Industrial Development Organization

APIFA0FIDIC

IAPHICHCAIDAIMOIS0PIANCUNCTADUNIDO

BACATC F SdwtFCLf.o.b.GNPgrtIRRLASHLCLLNGLPGn.a.NPVPERTroiror.p.m.TEUVLCC

Other abbreviations

Barge aboard catamaranContainer freight stationDead weight tonnageFull container loadFree on boardGross national productGross registered tonnageInternal rate of returnLighter aboard shipLess than full container loadLiquid natural gasLiquefied petroleum gasInformation not availableNet present valueProgress evaluation and review techniqueRoll-on/roll-off (of cargo loading and unloading)Revolutions per minuteTwenty-foot equivalent unitVery large crude carrier

xiv

INTRODUCTION

(i) For many years the UNCTAD secretariat,through its Ports Section, has made consistent efforts tohelp developing countries in their task of extending andmodernizing their seaports. which form a vital link inthe chain of transport. The training of competent per-sonnel, for both port management and port planning.has been one of the main goals. Port training courses,fellowships and a number of technical publications havebeen widely used by UNCTAD for this purpose.

(ii) It became apparent during the course of thiswork that there was a real need for a reference book inwhich the basic principles of modern port planningwere summarized in an easily understood form. Thepresent handbook is intended to meet this need.

(iii) The paramount importance of a far-sighted portdevelopment policy does not appear to have been fullyappreciated in the past by many governments. As a re-sult, ports have often been unable to keep up with therate of expansion of a country’s overseas and coastaltrade.

(iv) The consequences of a failure to provide properport capacity before the increased traffic arrives areclearly illustrated by the frequent congestion whichoccurs in ports in both developed and developing coun-tries. The enormous sums of money lost through con-gestion would often have been sufficient to build anextensive system of modern ports.

(v) Seaports can, moreover, play a major role inpromoting international trade by generating commer-cial and industrial activities which directly assist theeconomic progress of the country. The history of manyports shows how a bold policy of extending and mod-ernizing ports can revitalize the economy of a region.

(vi) The immediate aim of the handbook is to offerdaily guidance to port planners and decision-makers intheir difficult task of formulating a national port de-velopment policy and preparing realistic programmesfor the extensian and improvement of individual ports.The long-range purpose is to contribute to the trainingin developing countries of competent port planners,able to co-operate on equal terms with internationalexperts and foreign advisers.

(vii) The first part of the handbook deals with gen-eral principles of port planning and with procedures tobe applied for establishing a practical and consistentprogramme of work, for forecasting traffic and produc-tivity, and for studying various problems that have adirect impact on the development of ports.

(viii) The handbook suggests that the preparation ofa port development programme should follow a defi-nite sequence of steps, which are outlined, so as toensure that the work of planners is more systematic andefficient and that nothing of importance is forgotten.

However, since it is impossible to deal adequately inone volume with the myriad problems that affect theplanning of a major port, it was felt necessary to con-centrate, in the handbook, on those points that appearto be least familiar to planners in developing countries,and to refer only briefly to other subjects. It is recom-mended that port planners should endeavour to buildup a reference library on the subject of port develop-ment, and to this end a list of publications by privatespecialists, international organizations and the secretar-iat of UNCTAD is appended to the handbook, inannex III.

(ix) In the second part of the handbook, methods ofplanning various kinds of port facilities are discussed.Procedures are described for the preparation of plansfor general cargo berths and for specialized terminalswhere containers or bulk cargoes are to be handled.Sound and realistic decisions on port investments mustbe based on accurate numerical analyses of severalalternatives and on correct procedures for selecting themost advantageous plans.

(x) The use of sophisticated methods has not beenrecommended. Instead, a set of straightforwardmethods has been developed by UNCTAD, mainly inthe form of curves and diagrams based both on empiri-cal data and on mathematical calculations. They offer adegree of numerical exactitude comparable to that ofmany of the advanced computer-based approaches andare more satisfactory for general use.

(xi) The decision to recommend simple manualmethods was taken after several years of testing thecomputer-based approach of the UNCTAD secretar-iat’s early work in the simulation of seaports. Althoughthat early work made possible the development of thesimplified methods recommended in the handbook,and served as a basis for the UNCTAD research pro-gramme on port development, it became clear to thoseengaged in the work that the use of computer-basedmethods by port planners in developing countrieswould be too costly, both in time and in scarce skills, tobe justified in the majority of cases. This conclusion hasbeen reinforced by the realization that, during thepresent period of rapid technological change, the inputinformation in those countries will continue for manymore years to be uncertain and inexact.

(xii) Port planners ought, rather, to bear in mindthat there is no substitute for experience and soundjudgement. Diagrams and formulae are merely anauxiliary tool for their work, a means of relieving themof time-absorbing calculations and of freeing theirminds for creative work. Port planning is a challengingand complex task but not an exceptionally difficult one.It requires a full understanding of the way in which anefficient port works, a sound knowledge of the general

1

economic conditions of the country, a good deal of book has called for several reprints. Rather than con-common sense and a certain talent for visualizing thefuture.

tinuing to reprint unchanged, it was decided to issue asecond edition. This allowed a number of improve-

(xiii) It is hoped that this handbook will prove to be merits and corrections to be made, and several chapters

a useful contribution to the common international goal to be brought up to date. The second edition takes into

of establishing a world-wide system of efficient ports. account the many valuable comments received and the

(xiv) The continuing heavy demand for this hand-experience gained in using the handbook as referencematerial for a number of training courses.

Part One

;’

>i .’

.-.. __ __._ .’

Chapter I

THE MANAGEMENT OF PORT DEVELOPMENT

A. The need for a national ports plan

1. Technological improvements in recent yearshave made it essential to plan the transportation systemof a developing country as a whole, in order to achievea balance between the capacities of the various parts. Inmaritime transport it is sometimes possible-particu-larly for bulk and unitized cargo movements-to in-clude the shipping. port and inland transport facilitiesin one co-ordinated plan. In other cases the ship trafficis not under the control of the planner and it is onlypossible to co-ordinate the port facilities with those ofinland transport and distribution. Planning a sea-portwithout considering the connecting road, rail and bargefacilities may lead to serious faults in national com-munications. This is particularly true in the case of de-veloping countries. m many of which the freight trafficis rapidly growing and changing.

2. Within the ports sector, a balanced plan isneeded for each class of maritime traffic. The numberof ports, their,specialization and their location have tobe considered. Smaller ports which play a special localrole may not develop to the same extent as the maingeneral cargo ports. but they contribute to the coun-try’s trade and need to be included in the national plan.It is sometimes convenient for planners in a major portto be given responsibility for planning the developmentof the minor ports on their part of the coastline.

3. Although some countries still permit free com-petition between their ports. this is no longer seen asacceptable where national resources are limited. Forexample, the trend towards handling bulk commoditiesat specialized, high-throughput terminals (the annualthroughputs of which are measured in millions of tons)means that the whole national traffic flow of a particu-lar product may be handled at one terminal irrespectiveof apparent geographical requirements. To allow thistraffic to spread over a number of ports. as may happenwithout national planning. will mean either that eachcan only afford to install low-volume equipment. whichw~ill not allow the country to take advantage of theeconomies of scale obtainable through the use of largebulk carriers, or that each port has to invest large sumsin under-utilized terminals. Either alternative will leadto steep increases in unit costs which may often faroutweigh the increased land transportation costs result-ing from the development of a single. specialized, high-throughput terminal.

4. For all classes of freight. there is a growing needto avoid the over-investment which can result fromcompetition in a context of increasingly expensive car-go-handling technology. These technological changesin transportation methods require such specialized car-

go-handling facilities that there is a strong case for theregional co-ordination of mvestments in specialized ter-minals. The joint planning of port investment by coun-tries sharing the same hinterland can clearly he econ-omically advantageous. but in any case it is now virtual-ly obligatory for each country to develop its own na-tional ports plan.

5. The factors which should be taken into consider-ation in the preparation of a national ports plan areillustrated in figure 1. It would be advisable to use thisfigure as a check-list to determine which aspects requirefurther study before any major port investment deci-sion is taken. The amount of work involved in a countrywith several ports would justify the maintenance of asmall permanent nucleus of professional planners. to beaugmented by an additional professional team when afull revision of the national plan is needed.

6. The main activities indicated in figure 1 are theforecasting of the national demand for maritime traffictransport. the surveying of existing ports and the na-tional surveying of the means of transport available formaritime traffic. In addition, where major new termin-als are under consideration, it would be advisable tomake preliminary surveys of coastal geology andhydrography.

7. A number of related plans will result from thisexamination: a maritime traffic assignment plan: a na-tional port investment plan: an inland routing plan anda coastal shipping plan. All of these will be conceived ata broad strategic level only, the planning of detailedfacilities being left until each specific port developmentproject is prepared.

8. In summary. three main duties can be identified:

(a) National port planning: this leads to several pol-icy decisions which define the role of each port, andensure that national resources are used in the mosteconomical manner;

(b) Port master planning: this gives the long-termpattern of development for a port, without specifyingthe time at which any one step in this development willtake place. It also sets in motion work which will beneeded later:

(c) Port project planning: this aims to turn each partof the master plan into reality at the right time, and inthe right form.

B. The national ports authority

9. A further requirement at this point will be a de-cision on the policy as to which parts of the port infra-structure will be paid for by the central government and

5

Industrial sector plans

F I G U R E 1National port planning

Technological

Other processing plantsSurvey of special traff ic

Refineries posribilitier

;. . . 9

, . . : . . . : ’

Ma jor s tockhold ing points

National pattern ofConsumption

General manufacturer

National coastal geology wrvey

National hydrographical survey

Regional development pol icy

For each port

Tradit ional hinterland

Local traffic demandGeneral cargo

Specialized traffic

International transit traff ic /

1.:

. , . : . : . . :

1

Survey o f exist ing ports

Existing facilities

For coastal trans.shipment

Road, rail, inland waterway and air route capacitiesBetween ports and demand centres Route capacities

Coastal routes connect ing ports

Existing coastal fleet

Road vehicle availabilitv>---F,eet capacitieP

Estimatednationalmaritimetraff ic

Port infrastructure funding policy

National port investment plan

National Coastal shipping planSUrYe” of c

transportfor maritimetraff ic

Rai l rol l ing stock plans

Inland waterway fleet

which by the individual port authority from its ownrevenue. There may be certain large capital expendi-ture items that would place too heavy a strain on portfinances if they were to be supported from incomewhile charges were maintained at a reasonable level.Some would argue that only the connecting road andrail systems should be excluded from financing by theport. and others that maior long-term structures such asbreakwaters and work such as approach channel dredg-ing should also be partly or wholly charged to the cen-tral or regional government. It is for each governmentto decide this policy according to the financial capacityof existing ports and the expected profitability of plan-ned new ports.

IO. In deciding to what extent the central govern-ment should retain the responsibility tar setting portdevelopment priorities, it should he borne in mind thatan individual port authority may be limited by its physi-cal boundaries from finding what is economzally theright location for a new terminal. In times of change, aport authority is likely to place emphasis on those alter-natives which preserve or enlarge its level of activity.Modern technological developments make such ten-dencies undesirable from the point of view of the coun-try as a whole. as the location of existing port facilitiesmay be inappropriate for the use of the new technolo-gles.

11. For such reasons there is a strong case for set-ting up a specialist government agency with the overallresponsibility for co-ordinating port policies at a na-tional level. To build up and maintain the capabilityneeded, and tq allow a free interchange of ideas withthe many interests involved. it may be more appropri-ate for the agency to be separated from the centralgovernment ministry concerned and to take the form ofa national ports authority with defined statutory pow-ers, such as those listed below. There is a close parallelto the move in a number of countries towards nationalairport authorities, national oil authorities and so on. Asmall permanent secretariat would be appropriate.

12. For efficient management of port activity, theoperational decisions should be taken locally; it wouldnormally be wrong to give a national ports authorityany operational responsibilities. Its main functionshould be one of co-ordination and regulation, the prin-cipal aim being to prevent the undesirable duplicationof investments. The statutory powers which it may beappropriate to give to a national ports authority are asfollows:

(u) Investment: power to approve proposals for portinvestments in amounts above a certain figure. for ex-ample, $5 million. The criterion for approval would bethat the proposal was broadly in accordance with a na-tional ports plan. which the authority would maintain.

(b) Financial policy: power to set common financialobjectives for ports (for example. required return oninvestment defined on a common basis). with a com-mon policy on what infrastructure will be funded cen-trally and what locally; advising the government onloan applications.

(c) Tariff policy: power to set a common tariff struc-ture (local conditions will determine to what extent theauthority should also regulate tariff levels).

(d) Labour policy: power to set common recruit-ment standards, a common wage structure and com-mon qualifications tor promotion; power to approvecommon labour union procedures.

(e) Licensing: where appropriate. power to establishprinciples for the licensing of port employers, agents,etc.

cf) Information and research: power to collect, col-late, analyse and disseminate statistical information onport actlvrty for general use, and to sponsor researchinto port matters as required.

(g) Legal: power to act as legal adviser to port au-thorities.

13. It would be advisable tar such an authority toset up a method of obtaining advice from persons withwide experience in the matters of harbours, shippingand inland transport, in industrial. commercial, finan-cial and economic matters. in applied science and in theorganiration of labour. An appropriate method wouldbe to co-opt such persons on to the Board ot the au-thority or on to its subsidiary committees. Liaisonwould also take place with national bodies representingshippers, shipowners. etc.

14. The risk involved in giving such an authoritypowers over port investments and tariff policy is thatadditional delays may be introduced. It would be essen-tial, therefore, to institute in addition an emergencyprocedure to speed up or even bypass the normal deci-sion process when, for example, there were suddenchanges in traffic or rapid increases in congestion.

C. Port development

1.5. Within the broad national strategy, the de-velopment of each individual port must be comprehen-sively planned. The development of a port consists of acombination of medium-term and long-term planningof new facilities plus-in the case of an existing port-aprogramme of short-term action to improve the man-agement, the present facilities and their use.

16. For each investment there must be, first. a plan-ning phase, which ends in a recommendation on whichcourse of action the port should follow, giving only abroad treatment of each technical aspect; secondly, adecision phase, which can be substantial and includesthe securing of funds: thirdly, a design phase, whichturns the chosen plan into detailed engineering designs,and lastly, the construction or implementation phase.This handbook is concerned mainly with the planningphase. and goes only into sufficient technical detail tosupply the information necessary to produce prelimin-ary cost estimates. Final cost estimates are predomi-nantly dependent on the engineering difficulty andmagnitude of the project. These estimates must bemade, and the subsequent engineering design and con-struction work carried out. after the conduct of moredetailed investigations by qualified civil and mechanicalengineers. in consultation with the port authority. Thishandbook makes no attempt to provide a substitute forthe use of such professional staff.

17. The long-term plan-the master plan as it isoften called-consists of a view of the future situation

7

as it will be after a series of individual developmentshave been carried out. However, it does not try to saywhether and exactly when each of them will occur,since this will depend on traffic development. The mas-ter plan will be set within the framework of the nationalports plan and in turn will provide a framework withinwhich the medium-term plans for action can be drawnup and specific projects defined. This principle of goingfrom a broad long-term plan to a detailed medium-termproposal should be a standard procedure.

18. The programme of immediate practical im-provements for the use of existing facilities can, how-ever, go ahead independently of the medium- and long-term plans. There will always be an urgent need formoderate technical and operational improvements,such as the extension of available storage space, theintroduction of additional cargo-handling equipment orthe purchase of pilot boats or lighters. Improvements ofthis kind are independent of future capital investmentsand should not be delayed until the main investmentplan is finalized.

1 9 . For example, the identification and removal ofbottle-necks which impede the productive flow ofgoods may be studied by the methods indicated in thereport of the UNCTAD secretariat on berth through-put.’ This approach can be undertaken at any timeindependently of the planning project, but it would beadvisable for sufficient analysis of throughput to bemade by the middle of the planning phase to givereasonable practical estimates of future productivities.The establishment of these estimates is one of the mostimportant and difficult tasks of the port planner.

D. Long-term planning

20. In order to prepare both the national ports mas-ter plan and the master plans for individual ports, theplanner needs to ascertain the development frameworkwithin which each port will be operating. To do this heshould consider the following aspects:

(a) The role of the port, which may include some orall of the following tasks:

(9

(ii)

(iii)

(iv)

(b)

To serve the international trading needs of itshinterland as reflected by traffic forecasts,either in total for all needs or excluding specificcommodities (e.g. bulk commodities which areto be handled at special terminals outside theport’s responsibility);To assist in generating trade and regional in-dustrial development;To capture an increased share of internationaltraffic either by trans-shipment or by inlandrouting;To provide transit facilities for distant hinter-lands not traditionally served or for neighbour-ing land-locked countries.The extent of the port’s responsibility for infra-

structure needs, as follows:

’ Berth Throughput: Systematic Methods for Improving GeneralCargo Operations (United Nations pubhcation, Sales No.E.74.II.D.l).

(i) Marine responsibility, which may be total, fromlandfall to berthing, or may exclude estuarial,river or canal approaches or the financing of ma-jor marine works (e.g. main breakwaters, capitaldredging) ;

(ii) Landward responsibility, which may be total, in-cluding road/rail links between port and inlanddepots, etc., or may exclude either links sharedwith other users or local connecting roads/sid-ings.

(c) The land-use policy for the port, which may havefreedom within fixed boundaries, or freedom to acquireor dispose of adjoining land either on the open marketor with compulsory purchase, or freedom to acquirenon-adjoining land for storage, for inland clearance de-pots, or for additional berths at new coastal locations.(d) The financial policy as regards the port, which

may be either fully commercial, self-supporting andwith freedom to set tariffs as necessary, or subject torestrictions on tariff policy linked to a limitation oncommercial accountability or subject to public controlas an instrument of national development.

21. The long-term plan will place more emphasis onwhat is desirable than on what the trends seem to showto be likely. The planner needs to place himself in thefuture situation, even if this is 20 years hence, and try todraw a consistent picture of all that he will find at thattime.

22. This picture will allow the planner to lay out asensible future situation which is at least feasible andfar-sighted, even if there can be no certainty that itsdetails are correct predictions. The land-use aspect andthat of the major water areas and channel develop-ments are the most vital features of the long-term plan.These must be provided for in a manner consistent withthe expected increase in traffic, which over a longperiod can be quite substantial (for example, a one-million ton level increasing by 10 per cent each year for20 years becomes 6.7 million tons). Modern technolo-gical developments have made the need for ample landspace still more imperative than was the case in thepast. A container terminal or a major terminal for oresrequires an area of tens of hectares. Clearly, failure toearmark substantial land areas may mean that residen-tial and other forms of development may use them upfirst.

23. The industrial planning policies of govern-ment-central, regional or municipal-together withthe national ports plan when available should givemuch of the framework necessary to set each port’sobjectives. But it would be unreasonable to expectthose responsible for such policies to be very precise atthe outset since their understanding of the possibilitiesof port development is likely to be incomplete. There-fore, after talking to the authorities concerned, andcollecting what views exist, the port planner will almostcertainly be left with some unanswered questions., Hewill then be forced to fill these gaps by making his ownassumptions on the long-term role of the port. It is farmore important to reach a reasonably comprehensiveinterpretation of this role, within perhaps one month ofstarting the project, than to attempt to get an accurateand formal official statement.

8

24. Ship-repairing facilities (dry docks, floating this field can be obtained from IMO and from UNIDO.docks, slipways, etc.) are often also under the controlof a port authority and need to be planned at the same 25. Bearing m mind the above comments, the stepstime as the cargo-handling facilities, in the master plan. to be taken in drawing both the national ports masterIt will be necessary to ask first whether such facilities plan and the individual port master plans may be sug-should bc located within the port area. and if so, what gested. Tables 1 and 2 set out one way of carrying outimpact they will have on zoning, ship movements. etc. the full task and refer to individual steps shown as aThis subject is not covered in this handbook; advice in sequence in figure 2.

TABLE 1

Procedure for national ports master planning

The eight mam raaks (Al to AX) are as follows.

1. Define natmnal econonuc ohlectives LII so far as the) affectports.

2. Defme the finenclal respons~hihnes of the ports.3. Define the ~lanmne resoonsibditux of the port64 Prepare a L&d na&~~l traffic survey.5. Assign traffic to Individual portn6 . Prepare a prelimrnary mvestment planI. Co-ordmate and ohtam approval of mdlvidual port master

PlZillS8. Prepare and publish the natmnal ports master plan.

Each of these tasks is described in more detail below.

i-ask AI Defirw natmnal economx objectwes as they affeci porrs

1. Hold prehmmary discussmns wth national econonuc planners.2 Collate published reports, etc.. and extract material relevant

to maritime traffic and to the connected networks.3 . Summarlze the broad impact of econamc pohcxs on port de-

velopment in a draft policy paper.4 . Discuss draft with national econormc planners.5. Revise and circulate pohcy paper.

l-

Task AZ Drfne ,financrai responsibiim of porls1. Rewew existing orders and leg&&on.2 . Ohrain wews of port authorities.3 . Spell out new policy in detail (e.g. common tariffs, required

return on investment. fund&4 . Discuss proposal with higher authority.5 . Draft new orders or decrees.

Tmk A3. Define planrung respor~sibilirres of ports

1. Rewew existing planning responsihilitxs.2 . Analvse need for regional or other structure.3 . Consider methods of planning any new ports.4. Consult wth port authoritxs.5 . Propose new structure. Discuss with lugher authority and re-

vise as necessary.6 . Draft any new orders or legrslation needed.

Task A4. Prepare a broad narronal traffic survey

Chapter III of Part one discusses this m detail

E. The sequence of investment

26. Strictly speaking, since the short- and long-terminvestment plans form part of the same sequence offinancial investment and of economic benefits, thewhole sequence should be considered as one pro-gramme, and the planner should look for the overalleconomic optimum for the whole series of investments.

27. But this is an ideal which cannot yet be realized,since the methodology necessary to calculate such a

9

Task A5, Asslgri tra)‘lic to mdwlduul porn

1. Prepare broad ongmldestmatmn diagrams for each principlecargo class.

2 . Examme scope for concentratmn of cargoes m each region orat natIOnal level.

3. Construct several alternative feasible traffic assignments.4. Roughly evaluate alternatwes and prepare paper on most

ecO”“m,c soI”tlons.5 Circulate paper to all departmentslorganizatlons concerned.6 . Draw up plan reconciling comments recewed and suhnut for

approval7. Issue approved plan

Task A6. Prepare n prelrminary invesrmenr plan

1. Ohtam port estimates of future productivity for each cargo-handling techmque in questmn.

2 . Compare traffic assigned to each port with Its rough existingcapacity for each class of traffic and cargo-handling technique.

3 . Roughly estimate scale of additional facilities needed.4. Roughly estmate investment imphcations.5 . Compare wth Ministry of Finance targets or other constraints

and report any divergence.6. Revise figures as necessary7 . Notify ports of figures to ewz framework for theu master plan-

“,“g.

Task A7. Co-ordinate and obtain approval of indwidualporr mm~erpia?LS

I Tabulate traffic forecasts used by each port and check for m-consistencies and duplications.

2 . Carry our broad economic comparrsan of any competing plans.3 . Carry out rough check of all capacity calculations.4. Revw plans as required.5. Calculate natmnal port mvestment total.6 . Dxcuss long-term port investment requirements with Ministry

of Fmance and revise as necessary.7 . Visit ports to discuss final master plans.8. Issue authonzations.

Task A8. Prepare and publish the national ports master plan

1. Assemble indtvidual port master plans into a national plan.2 . Publish the master plan in a form whxh can he easily revised.

A diagram showmg these tasks and how they are related to masterplanning is given in figure 2.

complex economic optimum is not yet satisfactory.”The best that can be done at the present time is to try toset out a series of the main investment alternatives andto calculate at each main date of investment and of

‘The mathematics involved are not complex, but the interactron ofcosts and benehts of varying sequences of mvestment produces aheavy load both on analysts and computer tune which, III view of theuncertainty in the forecasts of traffic. productivity and costs, is notjusrifled

.._ -

TABLE 2

Procedure for individual port master planning

The 11 main tasks (Bl to Bll) are as follows:

1. Set up an ongoing traffic analysis (if this does not alreadyexist).

2 . Prepare a broad long-term traffic forecast.3 . Initiate any broad engineering surveys needed.4 . Analyse the port’s role as laid down by the national authority.5 . Determine the long-term phased area requirements.6 . Determine the long-term wafer and channel requirements.7 . Assign traffic to major port zones.8 . Calculate the rough cost of each terminal/berth group in each

phase.9. Prepare the draft master plan and submit for national

approval.10. Revise and publish the port master plan and obtain local

approval.1 1 . Install a control system for initiating a project at the right

time.

Each of these tasks is described in more detail below.

Task Bl. Set up an ongomg trnffi analyser

The data required are shown in chapter III, “Traffic forecasting”.The UNCTAD “Manual on a uniform system of port statistics andperformance indicators”” contains a complete system for collectingthe data both for planning and for operational purposes.

Task B2. Prepare a broad long-term traffic forecasr

Strictly speaking, the ports cannot start forecasting until their rolehas been defined at national level, but there is a lot of preparatorywork and simple projections which need not wait for this. At themaster planning stage, forecasting is to be broad and long term only.

Task B3. Initiate any brood engineering surveys needed

The surveys that should be initiated for master planning are thosewhich provide a broad picture on which major zone decisions can bebased, plus those [like siltation studies) which are themselves of along-term nature. The range of surveys which may be needed aredescribed in chapter VII, “Cwil engineermg aspects.”

Task 84. Analyse the port’s role as laid down by lhe nafional au-thori ty

If the national plan has not been prepared, it may be necessary toanalyse the port’s role as seen locally and submit this as a proposal.

Task B5. Determine [he long-term phased area requirements

For each of the traffic streams likely to result from the defined roleof the port:

1. Review characteristics of each class of traffic (transport, stor-age, ship size and draught, pollution).

2 . Review industrial development plans and possibi!ities in portarea.

3. Calculate broad land area requirements for the range of feas-ible long-term cargo throughputs.

4 . Estimate land area requirements for long-term industrial de-velopment within port hmits.

5 . Estimate land area requirements for ancillary land-use (hous-ing, amenities) within port limits.

6. Tabulate the various area requirements phased according toeach traffic alternative.

Task B6. Determine the long-term wafer and channel requiremen*i

For each class of ship traffic, calculate the broad water area anddepth requirements for the range of ship types and sizes expected inthe long term.

Task 87. Assign rraffic to major porr zorzes

This task is discussed further in chapter V of this handbook. Thefollowing is a sequence of work which is appropriate at the masterplanning stage:1. Examine environmental impact of each class of port activity

(both independently and as they affect each other).

WNCTADISHIPI185IRev.l.

2 . Survey existing water areas and approaches and compare dif-ferent ways of deepening and extending these, including newland cnts.

3 . Survey existing and available land areas and compare alterna-tive ways of extending them, includmg reclamation.

4 . Draw alternative zone configurations wth corresponding com-munications corridors.

5 . Broadly evaluate alternative phased configurations for trans-portatlon economy, capital cost and flexibility.

6 . Prepare zonmg plan for the preferred solution.7 . Draw outline charts of water depth for the chosen zoning con-

figuration, corresponding to the successive phases of eachalternative.

Task B8. Calcuiare the rough cost of each terminallberrh group

1. Identify likely terminal or berth group developments, in eachzone within the zoning plan, for each future alternative.

2 . Estimate the rough costs of each termmal development.N.B. Although it will be difficult to obtain such cost esti-mates, it is important to find any indicatwe figure, howeverrough. This is because without such figures it will be impossibleto build up a long-term investment plan, which is essentml toshow whether the master plan is feasible.

3. Tabulate the results.

Task B9. Prepare the draft master plan and submt for nnrionalapproval

The contents of a master plan should include:(a) The long-term forecast and its rationale;(b) The planning maps;(c) The investment implications.

One way of organizing the preparation of the plan is as follows:1. For each class of port activity, combine the successive stages of

development in the alternative cases into a single frameworkindependent of time.

2 . Draw planning maps showing the proposed zoning and alterna-we development sequences within the framework.

3. Prepare order-of-magnitude investment cost figures for the de-velopment sequence of each activity.

4 . For the time-scales both of a conservative and of a radicalalternative, calculate the total investment implications over theperiod.

5 . Assemble this material into a draft master plan, with a sup-porting commentary on assumptions and rationale.

Task BlO. Revire and publish the agreed pm muter plan

This should be published in such a form that it can be easily revisedand amended each year.

Task BII. Install a control system for initiafing a project at the right*ime

It is essential to initiate a project feasibility study as soon as there isan indxation that, by the time the development is complete, therewill be enough traffic to justify it. Master planning is not completeuntil a routine is established for checking when projects should beinitiated. The following procedure is one way of doing this:

On completion o f the master plan1. Identify each individual investment project withm the plan

over the next ten years.2 . For each of these projects, estimate the likely development

time that will elapse between initiating project action andbringing the facilities on stream. This will include: the wholesequence of project planning; funding and time for decision-making; tendering; design and construction.

Every year1. Bring the traffic forecast up to date, for each traffic class.2 . Estimate the future growth rate of traffic in that class, taking

account of latest dev;lopments and customer requests. I3 . At this growth rate, calculate the traffic level a number of

years in advance of the date at which the project capacity isneeded. This is the triggering level.

4 . Activate the project if the triggering level has been reached.

-._ --

62EH2~--_------_--------- 1

11

commissioning what will be the costs and the benefits.Planners may be assisted by research units or consultingfirms in making a broad pre-investment study of thecountry. The basic aim will be to determine the generaldirection of expansion and to quantify the tonnage tobe handled and how it will be shipped. By making cal-culations for a range of possible investment program-mes for this traffic, the planner may succeed in devisinga programme which is not too far from the optimum,although even this will entail a good deal of work. Tosimplify the process, only rough calculations need bemade during the initial phase of filtering out optionsmentioned above. The long-term plan can be based ona definite sequence of investments. largely irrespectiveof the rate at which trends develop, so that, althoughthe sequence itself may be fairly firm, the timing ofthem will be flexible.

28. The master plan should have a continuous exist-ence as a formal port reference document. It should bemodified periodically, either as a result of a definitedecision to take a fresh look at the whole future situa-tion at a given date (and in the present rapidly changingtechnological stage in shipping a three- to five-year re-vision would be advisable) or as a regular activity with-in an annual traffic review.

F. Maintaining capacity during engineering work

29. An existing port must continue to provide anundiminished service during the execution of an im-provement or extension project. It is usually the expec-tation of more traffic than can be handled that is thejustification for the project, and it will be self-defeatingif the project work itself is allowed to cause congestionfrom which it may be difficult to recover,

3 0 . An operational programme must be prepared,showing, for the whole duration of the work, how thegrowing traffic is to be handled in spite of any closuresor obstructions. This may show that there will be a needto provide additional temporary facilities purely tomaintain capacity during the execution of the project.Such facilities are a financial charge to the project andit may be that their cost will swing the balance over tothe choice of a different engineering option. In anycase, there will need to be a careful phasing of theengineering work and the commissioning of temporaryfacilities.

31. The difficulty of maintaining capacity may evencause the port development strategy to be modified.For example, the construction of a new group of berthsin two stages may cause less interference in operationsthan closing a larger area of the port to build them all inone project. Conversely, the faster completion of thegroup in one project instead of in two consecutive par-tial projects may in certain cases be less disruptive.

G. Project planning; the feasibility study

32. A project plan usually takes the form of a feas-ibility study of the best way to satisfy a particular re-quirement, and it is followed by the design phase. Theproject plan must be consistent with the master planand it must be seen as one step in its implementation. A

feasibility study claiming to show the need to deviatefrom the master plan must produce strong evidence insupport of this claim. If the deviation is accepted, themaster plan will need to be revised to take account ofthe possible effects on other facilities. All these proces-ses take time, and there may be instances where duringthe time-lag a clear case develops for a change of direc-tion-for example, if there is a development in technol-ogy. It could then be fully appropriate to make thenecessary changes even in mid-project, provided thatthe cost implications are clearly analysed and accepted.

33. Each feasibility study should preferably coveronly one proposal. For example, the decision to build acontainer terminal should be studied as a separate issuefrom the decision to enlarge the storage capacity of thegeneral cargo berths. Very often, however, both forreasons of administrative convenience and because ofphysical relationships within the port, several such pro-jects are combined in one feasibility study and one re-port. Although this is acceptable, the numerical analy-ses for the various projects should be separate. It is nothelpful to include in one economic or financial ap-praisal several different investment proposals. For ex-ample, a combined proposal for two additional break-bulk cargo berths and a new bulk cargo terminal willconfuse the decision if only one set of cost and revenuefigures is given. It may be that the break-bulk cargoberths are economically justified but are financiallyloss-makers; the joint proposal will hide this fact andconceal a cross-subsidy from the profitable bulk cargoterminal. This subject is discussed further in chapter II“Planning principles”.

34. Inevitably there will be several areas wheretechnological changes are taking place which mightmarkedly affect the investment plan. Some of these willlie outside the port personnel’s own experience, andthe project leader of a port development project shouldseek external advice on these subjects. For example, itshould not be his responsibility to carry out an exten-sive review of the trends in ship technology or cargo-handling methods. Much work has already been doneon these topics, and he should be able to refer to it. Inthe case of any difficulty, reference can be made to theUNCTAD secretariat, which will help wherever pos-sible.

35. Similarly, in economic forecasting, it is not thejob of the port planner to carry out an international oreven a regional trade forecast, however importantthese are for him as a basis for calculation of the ex-pected traffic. He should go to other sources for sucheconomic forecasts-normally, the national economicplanning agency. However, having pursued thosesources as far as possible, he is likely to be left withincomplete information and to have to collect furtherdata himself through various sources such as tradersand banks.

36. The procedure of devising a project plan in-volves finding the solution to a specific requirementand culminates in a justification for investment. It isnormally carried out as a clear-cut project with a well-defined programme of work. It is advisable to prepare asummary bar-chart of the full range of project activi-ties, in a form similar to that shown in figure 3. Dia-

1 2

A typical port planning sequence

- TIME NOT TO SCALE B

MASTER PLANNING

Set up ongoing traffic analysis

Broad traffic forecast

Define role of port

Broad engineering surveys

Traffic allocation plan

Plans for: land use

water areas

approach channels

Land transport policy co-ordination - - - - - -

I

PROJECT PLANNINGPROJECT PLANNING

Reexamine and update the master PlanReexamine and update the master Plan

Traffic forecastingTraffic forecasting

Engineering al ternat ives and cost est imatesEngineering al ternat ives and cost est imates

Specific site surveysSpecific site surveys

Operational planOperational plan

Performance calculat ionsPerformance calculat ions

Cost-benefi t analysisCost-benefi t analysis

Financial analysisFinancial analysis

ReportingReporting

SHORT-TERM IMPROVEMENT PLANNING

Berth throughput analysis

Removal of bottle~necks

I Broad project Feasible opt ions Preferred SiART OFplan agreed specified option chosen DESIGN PHASE

+I Productivity forecast

----------+

grams of this kind show a sequence of activities, point-ing out which ones have to be terminated before thenext one starts, and thus need to be given priority; theyare useful in setting out the range of tasks and skillsneeded. But they should not, once published, betreated as sacred. In particular, it is not advisable toprevent a subject from being considered before itsscheduled time on the chart.

37. The central portion of the bar-chart in figure 3dealing with the project plan has three main stages indi-cated by the vertical arrows. The first stage which, aftera period set aside for agreement by the authorities,leads to a broad project definition, should take perhaps10 per cent of the time available, although if littlethought has been given to the needs of the future portbefore starting the project, 20 per cent might be moreadvisable. Furthermore, if no master plan exists, it maybe necessary for a substantial amount of time to beallocated first to the collection of traffic data and to thecarrying out of preliminary geological and hydro-graphical surveys.

38. The work of the second stage includes thepreparation of detailed traffic forecasts and broad

engineering studies, and the specification of all thefeasible alternatives, together with rough cost estimatesfor each. It also includes the important task of consider-ing, for each alternative, what operational plan andcargo-handling methods will be used. In order that theanswers to these practical questions should be realistic,a productivity forecast should be made on the basis ofprogress recorded to date in consequence of the short-term improvements. This stage should take at least 30per cent of the project time.

39. Bearing in mind the above remarks, a pro-cedure for planning individual projects can be fol-lowed. One step-by-step procedure is shown in figure 4.It consists of two passes through the tasks, the first at abroad level and the second in more detail. In practiceplanners will rarely be able to follow the procedureexactly in any particular case, and many of the activitieswill be going on in parallel. There may also be the needfor more repeated recycling and improvement of dataand analysis. Nevertheless, it is advisable to bear inmind the theoretical sequence and structure of theplanning process. The steps are listed and explained intable 3.

TABLE 3

Procedure for port project planning

The 18 mam tasks (Al to A18) are as follows:

Task Cl. Derailed traffic forecast

Revise master plan forecast and detailed figures for the economiclife of the investment proposed.

Task C2. Survey of cargo-handling techniques

For each class of traffic that has been forecast, examine the alterna-tive port-handling techniques and thex impact on future producttvity,bearing in mind the expected form of presentation of the cargo.

Task C3. Rough dimensions

Group together traffic classes with similar handhng characteristicsand, for each berth group or terminal, find the approximate level ofadditional facilities needed and make a rough estimate of theirdimensions.

Task C4. Airernarive locations

For the berth groups and termmals concerned, propose alternativewater and land areas in locations that will not interfere with traffic inadjoining zones and that will provide safe berthing.

Task C5. Engineering surveys

For each location, carry out the engineering studies to quantify themain works required and adjust site locations where necessary toavoid excessive costs. Although engmeering surveys should be car-ried out after task C4 and before task C6, in practice they may needto be continued for the whole period, providing more accurate resultsas the survey proceeds.

Task C6. Rough cosfs

Estimate the cost of constructing and equipping each of the facili-ties under consideration.

Task C7. Seleclion of promising optmnsEliminate the less attractive alternative solutions, discuss conclu-

sions with the decision authority and obtain agreement on a short listof alternatives to be further studied.

Task CS. Labour constraints

Consider the labour questtons and manning problems which mayarise with respect to each alternative technology m parallel with taskc7.

Task C9. Preiiminnry dexgn

For each alternative retained, design the layout of all facihties inuffxient detail to dtscover access, operating or storage problems.

Task CIO. Operorionnl planning

Prepare plans showmg the equipment and operation of the newiacilitles, and the productivity targets.

rask CII. Capacity caicuimionsCalculate the alternative levels of facilities needed to accommodate

ih$ range of capacities and services that is feasible.

Task C12. Union comulration

Initiate consultation with trade unions on any new cargo-handlingtechniques proposed.

Task CH. Cost estimnres

Refine the cost estimates for all works, equipment and services toproduce a basis for the economic and financial analysis.

Task CI4. Cost-benefit analysis

Analyse the economic case for each of the alternatives.

Tusk C15. Finnncial analysts

Analyse the financial viability of each option and review the avail-able methods of achieving sound financing.

Task 136. Draft proposal

Consolidate all analyses and compare advantages and dtsadvan-tages of each option in a draft report.

Task C17 . Narionai and local approval

Discuss draft report with local and national authorities and ohtamagreement on recommended solution.

Task Cl8 Final proposal

Formalize the agreed solutions in a report wtth the supportingW.lyXS.

1 4

F~c;ultr 4

The planning S-quence-11

First run through

Cl Detailed1 t r a f f i c forecast 1

III c2 survey of ’cargo-handling ,techniques

f5 Engineering s u r v e y s

II c3 Rough ~4 Alternative 1 C6 Rough costs lC7 Selection of

dtmenaiona locations 1 promisingOptImP PI

, C8 Labour Iconstraints

C: Praiect planning

D E C I S I O N 0 C9 Preliminary

I des’gnIII

[Cl3 Cost Cl4 Cost-benefit

estimates , analysis II1 C l 5 Fmancial !analysis I

1 C l6 Draf t I

proposa l

NATIONALAPPROVAL

ILOCAL oI Cl8 FINAL

APPROVAL PROPOSAL

40. The third stage involves the carrying out of theanalyses which will show which of the alternatives arethe more attractive, and it culminates in a recommen-dation for a single solution. It is likely to be the longeststage, taking more than 30 per cent of the time. Itincludes, first, the carrying out of performance calcula-tions to determine what level of service will be given byeach combination of traffic and facilities, and then, onthe basis of these performance figures, the filtering-outof alternatives, with the use of economic and financialanalyses. An 18-step list of the tasks involved in thepreparation of a port development plan is given in table3. The sequence of tasks illustrates the method ofgradually narrowing down the alternatives.

H. The analyses needed

41. In the third stage there is a danger that an inex-perienced team will put the emphasis on the wrongtask. The economic cost-benefit analysis and the finan-cial analysis, which shows whether a facility will pay foritself, are by far the most important tools to be used inreaching the right investment decision. However, theyentail rather laborious and routine calculations whichare less interesting to make than the calculation, bynovel methods, of the performance of each of the alter-natives for the various forecast traffic levels. Theappeal of such performance calculation techniques (forexample, that of simulation with the use of a computer)can lead to an excessive amount of the valuable projecttime being spent on them. If a team has a suitable

simulation model available, and is experienced in itsuse, then the work can be done quickly. If, however,the team is new to the method, it should on no accountset out to learn the technique during a port investmentappraisal. The gain in precision will certainly be at theexpense of an excessive amount of time and effort.

42. However, the performance calculations are im-portant and some of the simpler methods which havebeen used in the past are insufficiently accurate forpresent needs. For this reason the UNCTAD secretar-iat has carried out a research programme for the de-velopment of a new methodology which will offer amiddle course between rules-of-thumb and computersimulation. This methodology is described in part twoof this handbook. It consists of sets of general curveswhich, given a reasonably accurate set of practical inputdata, give a sufficiently accurate basis for the economicanalysis. The performance curves provided have beendeliberately designed to have an accuracy matched tothe accuracy of the relevant facts and figures known toa typical port planner.

43. To reach a single recommendation on invest-ment, the calculations will need to be done for a num-ber of cases, each concerned with the handling of futuretraffic by a set of future facilities working at a futureproductivity. The relationship of these informationneeds in port development planning is shown schema-tically in figure 5. Central to this information are theoperational statistics necessary for productivity fore-casting.

FIGURE 5Information needed for port development project

En$gi;;ngEnvironmenta l Development

t rends considerations constraints

1 ! I DevelopmentInventory of

DEFINITION OF FEASIBLEobjectives

exist ingfacil i t ies PLANS

II ICargo-handl ing

te;;;;yv

Performance!i

statistics __L PRODUCTIVITY FORECAST - bS

t s’Productivityconstra ints

I

Tradet rends

Ship andty;;;lPgv

Packaainatechnoiog~

t rends

Developmentplan

1 6

44. In summary, the port planning team will needto be provided with the skills and the time needed tocarry out each of the following analyses:

(a) A performance analysis to determine the effectof different levels of port capacity on the level of ser-vice provided to the port‘s customers;

(b) Engineering studies to determme the feasibilityand approximate cost of each design;

(c) Operational planning to determine how theproposed facilities will be used and what the productiv-ity and the operating costs will be;

(d) An economic analysis to compare the desirabilityof each alternative in terms of the stream of costs andbenefits it generates;

(e) A financial analysis to determine what the rev-enue will be at different traffic levels and tariffs andwhether such revenue will support the costs of thefacilities and the servicing of any loans. The effect ofthe project on existing costs and revenue, and the re-sulting financial viability of the whole port, must alsobe studied.

45. Certainly, the whole project involves a consid-erable amount of work, but in view of the importanceto the national economy of finding the right decision,this work is fully justified. It is just possible to bring allthese calculations together in one computer modelwhich provides an “optimum” solution. However. thisis a very expensive procedure and unsatisfactory as abasis for investment decisions. Planners should rathercontinue to carry out an individual analysis. with con-sistent data, for iach of the alternatives they wish tostudy in detail. Where the team has access to computerfacilities and skills, these should be applied first to thelaborious but straightforward task of carrying out acost-benefit analysis of a range of alternative proposals,and of their sensitivity to uncertainty in the input data.A well-documented computer programme for this workis available on request from the Central Projects De-partment of the World Bank.

I. Ancillary services

46. A complete port development plan must in-clude provision for many facilities which are ancillary tothe main port operations of trans-shipping and storingcargo. These range from fire-fighting and rescue ser-vices to document-handling and data-processing sys-tems. Ancillary services are discussed individually inlater chapters and a check-list is given in table 4. Theywill generally require financial provision, which in totalcan be a substantial addition to the overall costs of theproject. Even if certain ancillary facilities were to befinanced separatelv, provisions should be made for anyland required within the framework of the land acquisi-tion plan.

J. Development of the port organization

47. The selection of an appropriate form of portadministration is a matter of port policy rather thanpart of the preparation of a specific port development

TABLE 4

Check-list of ancillary port services

1. Pilotage:2 . Tug>:3 . Harbour cratt:4 . P;awgation ada.5. Fire-fighting lacihtws;6. Rescue serwce,7 . MedIcal SC~\‘ICZ,8. Port secure) and pohcing scr~~ccs:9. Dangerous mntenal area;

10. Equpment mamtenance areas;11. &nrkens;12. Rest-rooms and temporary hvmg quarters;13 Recreational laaht~es for shw’ crers and purr workers:14. Fuel bunkermg facilmer;15. Serwces (water, electricity, seweragcl:16. Ships‘ prov,sion\ and spare parts;17. Minor repair facilities;18. Quarantine facilities;19. Ltghtlng (lor mght work);20. Communnetiona (including ship to shore);21. Pollution control (huffer zones. faal~t~es for purification 01 con-

tammated waters);22. Waste disposal (dumping areas, incmerators. crushers);23. Environmental protectlo” (beaches. green seas. open spaces,

landscaping)

plan. The basic system of port administration, whetherit is to be an autonomous or a centrally directed admin-istration. should be determined by the national portsauthority. However, there are certain organizationalelements of the administration which are the responsi-bility of the local port authority. A check-list of theseelements is given in table 5.

TABLE 5Check-list of organizational elements needed in a port administration

1. Organizatlonai structure:2. Admmistrattve procedures:3. Cost analysis and control;4 Tariff structure:5 Consignment documentation and cusrorns procedures;6. Electronic data processing and telecommunications systems;7. Data collection, analysis and dtsseminatmn procedures;8. Staffing and manning polues;9. Staff selection procedures.

IO. Training programmes:11. Marketing and public relatmns (includmg the education of poten-

tidl users of a proposed new faclhty).

48. In the case of a new port or of an independentport terminal. planners should take the opportunity tomake suggestions for modifying and improving theseorganizational elements. The possibility of escapingfrom traditional bad practices can be a powerful argu-ment for developing a new port rather than expandingan existing one. But even in the latter case, where theproposal is for further development of an existing port.the opportunity to introduce modern managementtechniques in the new facilities should be taken wher-ever possible. In particular, the introduction of newtechnologies can spur changes which will improve theoperations. For example, the development of a con-tainer terminal can be accompanied by the introduction

1 7

of modern data-processing methods to improve thequality of the information necessary for managers tocontrol the flow of containers.

49. In any case, whether or not major investmentsare being made, as the demands on the port change andas the modern business environment changes, theremay be a need to adapt the organizational structure ofthe port and possibly to introduce new functions.

50. It is difficult to generalize as to the best organiz-ational structure for a modern port, but a typical struc-ture is given in figure 6. Attention is drawn to the plan-ning section within the management services depart-ment, with responsibility for the following tasks:

(a) The analysis of trends in existing traffic and per-formance statistics;

(bj The analysis and forecasting of future traffic, interms of shipping and cargo tonnage by types androutes;

(c) The evaluation of information on new technol-ogies in ships and cargo handling as they affect thefuture port tasks;

(d) The analysis of requirements in water and landareas, equipment and storage;

lalson with all other planning authorities con-ce%d:’

cf) The preparation and maintenance of the portmaster plan;

(g) The preparation of specific project proposals.

For major new works, an implementation section maybe formed within the engineering department which isgiven responsibility for the construction of the newworks.

51. There may be local reasons why the structureshould be substantially different. Further, it should beappreciated that such an organization is more particu-larly appropriate to a larger port which is to a greatextent responsible for its own affairs. For smaller ports,or where it is more appropriate for control to be exer-cised over several ports together, a number of theseresponsibilities would naturally be assumed by theappropriate ministry or by the national ports authority.Nevertheless, it would be unwise to transfer any of thefunctions listed entirely to the central body. Howeversmall the port staff may be for the performance of aparticular function, a substantial degree of authorityand skill should be retained at each port. An exceptionto this may be the legal affairs function, for which itmay be difficult to justify keeping professional staff ineach port.

K. Project control

52. It is not necessary, for the supervision of a gen-eral port planning project, to use methods of monitor-ing and control as detailed as those of the engineerswho will have to design or construct the facilities. Theuse of a PERT network is out of place here and criticalpath methods make little sense in this type of analyticalproject.

53. A simple method of control is to identify SW-

cessive goals, or “milestones”, along a bar-chart, andto check progress towards each of these goals at regularprogress meetings. Satisfactory “milestones” can besimply the completion of the three stages described,each ending with an intermediate decision.

54. Monthly progress meetings would be appropri-ate in most cases. These meetings should be informal,technical and as extensive as the subjects demand. Thiswill often require at least a half-day of discussion aboutthe work, and this time should be considered wellspent.

55. Formal progress reports to management orother authorities can be dispensed with in many suchprojects. Automatic monthly or three-monthly reportscan do more harm than good. A better method is toprepare a report only when there is something of in-terest to report on, and to provide, on a regular basis.only very brief notes on the subjects discussed at theprogress meetings and the actions agreed on. A time-table for producing drafts of reports should be agreedupon in advance.

56. It is inadvisable to delegate responsibility forthe whole project to an analyst and let him work in aback room for six months. He must be drawn out of theback room very frequently for discussions with thosewho know the practical problems. This means thatprogress meetings should be regularly attended bysenior managers responsible for traffic operations andby members of the engineering department. It is moreuseful to have their views as the work proceeds than toreceive their comments after it is finished. However,the project leader must take the initiative in driving onto the end of the project, whatever doubts are expres-sed (on data accuracy, forecast accuracy, etc.), after hehas listened to all comments. Doubts expressed at pro-gress meetings and the need for discussions on technicalpoints should not be allowed to cause delays. The pro-ject leader should insist on steady progress on the basisof the best information he has available, with the objec-tive of reaching the scheduled “milestones”.

L. Use of consultants

57. In many cases the planning agency concernedwith the port development will feel that it lacks certainof the skills needed to complete the work, and, whilstretaining overall control, will wish to hire individualspecialists in the missing skills. In other cases, it will befelt preferable to contract out the work in its entirety,Both alternatives are acceptable, but in the hiring ofoutside assistance certain points should be borne inmind:

(a) Past work, and previous planning studies, even ifshelved and not acted upon, should be made availableto the new team. Furthermore, even if there are pointsto criticize in such past work, it will often be morevaluable to engage the same team again to carry out arevision or to study a new requirement, than to make afresh start with a new team.

(b) It can cost more to ask for urgent early answersthan to give the consultants more time to carry out thework at its natural pace.

1 8

Flcun~ 6

Typical port urganizational structure

D I R E C T O R G E N E R A L

PORT USERSADVISORY COMMITTEE

MARINE TRAFFIC MANAGEMENTSERVICES

SECRETARIAT FINANCE ENGINEERING

issistant Director-General Assistant Director-General Assistant Director-General Assistant Director-General Assistant Director-General Assistant Director-Generafor Marine for Traffic for P lanning for Administration for Finance for Engineer ing

Director of marineHarbour masterPilotsPort craft operatorsSignal tower staff

Director of trafficWhar f super in tendentWharf inspectorsShed foremenPier superintendentPort labour

Economist Secretary DIrector of financeSystems analyst Legal adviser Chief cashierEngineer Director of establishment Statistics officerCargo-handl ing expert Port pol ice

Civil engineersElectrical engineersMarine engineersMechanical engineersDraughtsmen

Channel maintenanceNavigational aidsMovement of vesselsUse of port craftControl of pilotsControl of marine

staffRegistration of

v e s s e l sSurvey of vesselsControl of signal

towerMarine statistics

Cargo handling Management information General and despatch Collection of revenues All civi l engineeringAllocation of berths system section Calling of tenders worksCommercial corres- Planning Port secur i ty Control, supply and Maintenance of

pondence and claims Port promotion Staff cars purchase of stores mechanical, electrical,Operat ion of sheds Market research Public correspondence Control and preparation marine and civilSubmission of out.turn Organiration and Accidents of budget engineering works

report methods s tudy Archives Preparation of salary Assistance in portSupervision of vessels Preparation of quarterly Preparation of agenda and bills planning

w o r k reports for Directory and minutes of Payments to staff Supervision ofOperational control of Gt-“C4 meet ings Payments of public bi l ls contractors’ work

mobi le equipment Liaison with heads of Preparation of monthly Supervision ofOperat ion of barges depar tments and annual f inancial slipway and mar ineControl of gates and Yeepingof confidential statistics workshop

cargo deliveries papers Electronic data processing

Operat ional stat ist ics Preparat ion of annualreports

Maintain files for leases,contracts and otherlegal matters

(c) The outside team should be contracted to spenda substantial part of the study period at the port loca-tion. In return they should be provided with a highstandard of office accommodation conducive to inten-sive work during this period.

(d) Consultancy contracts should name the indi-viduals to be employed on the contract and care shouldbe taken to check the capability of the individualsnamed. It cannot be assumed that a high-grade corpor-ate capability will be reflected in high-grade individualperformance if this is not done.

(e) A liaison officer should be named by the author-ity to provide a single point of contact with the team,and this officer should be given a satisfactory level ofauthority in technical and administrative decisions.

M. UNCTAD assistance

58. Assistance in any of the matters discussed inthis handbook can be provided by UNCTAD. Informalrequests for minor points of advice may be directed tothe UNCTAD secretariat in Geneva. More substantialassistance can be the subject of a technical assistanceproject within the United Nations Development Pro-

gramme, formulated in consultation with the residentrepresentative in the country concerned.

N. Port development finance

59. The scale of port development can be verylarge, and in the case of an expanding economy thefunds needed will usually require joint action by centralgovernment, local municipality and, where appropri-ate, with international financing organizations.

6 0 . Development projects of as little as one milliondollars may be of value, but the more usual port projectis more likely to be measured in several tens of mil-lions. At the upper end, it is interesting to examine thefinancing of a major, self-contained development near-ing completion at the port of Kobe, Japan. This takesthe form of an artificial port island of reclaimed land, asillustrated in figure 7.

6 1 . The development of Port Island, Kobe, is partof the Osaka Bay Port Development Authority’s mas-ter plan agreed on in 1968, and in fact reclamation hasbeen in progress since 1966. The work, which is de-signed to provide 11 container berths and 18 generalcargo liner berths, together with full operational and

FIGURE 7

Port Island, Kobe, Japan

PORT ISLAND. KOBE

commercial facilities, will be completed in 1980-a to-tal development period of 14 years. The first berth wasbrought into operation in 1969, three years after thestart of work on the project.

62. The total budget for the Port Island develop-ment was $466 million. This figure includes the cost oftransferring 80 million cubic metres of soil by belt con-veyor from a nearby mountain site to the shore andthen by barge to the reclamation site. The financing ofthe project was arranged as follows:

PercentageGrants from the central government .,., .., ,.. 1 0Grants from the municipality concerned 10Long-term financial loans from the central government 40Long-term financial loans from the private sector (shippmg

companies and terminal operators with exclusive use of facili-ties) 40

The 80 per cent long-term loan funds are in the form ofthe issue of Port Development Authority bonds.

0. Contents of an investment proposal

63. The proposal for a major port investment pre-pared for submission to an investing authority shouldbe set out in a manner similar to the following:

(a) Rationale for the proposal;

(b) Status of the proposal (will the project proposedcompete for capital with other projects, or is it an alter-native to another proposal?);

(c) Traffic forecast, giving background assumptions,expected future developments, and margin of uncer-tainty;

(d) Productivity forecast, giving reasons for any esti-mate which differs from the current productivity, andany training needs associated with this;

(e) Operating plan for the new facilities, includingtraffic allocation policy and contingency plan forperiods of peak demand;

(f) Performance analysis, indicating expected turn-round times and berth-day requirements for each classof traffic;

(g) Tariff proposal;

(h) Cost-benefit statement;

(i) Financial statement, including cash-flow forecastand statement of risks and uncertainties.

P. Procedure for implementation of port projects

1. THE IMPLEMENTATION SEQUENCE

64. The last phase of preparatory work for a portdevelopment project consists in making arrangementsfor construction. The best plans can be seriouslyharmed by unsatisfactory construction work or by ne-glect in selecting the correct building materials. Thespan of useful life of newly built facilities may beshortened, and consequently the amortization of theinvested capital made more difficult. Moreover, urgentlyneeded works may be delayed unless the actual im-plementation of a major port project is carefully pre-pared.

FIGURE 8The overall procedure for port development

YEARS* 3 4

21

-

FICUREYA typical tendering sequence

M O N T H S

I 1 I 2 I 3 I 4 I 5 I 6 I 7 1 6Despatchte”d.%documents

A U T H O R I T Y

from contractors

C O N S U L T I N G

E N G I N E E R

Prepare tender documenrr

M I L E S T O N E S :t

Decisionto proceed

Pre-qualified TenderCO”frKtOrl documentsselected to in handstender of tenderers

Closing datefor tenders

Signmg ofContracts

6 5 . The feasibility study shown in the central por-tion of figure 3 is followed by a design phase of theselected alternative and is normally carried out by con-sulting engineers. The field investigations discussed inchapter VII; “Civil engineering aspects”, are carriedout, and detailed layout and design of all facilities iscompleted, together with cost estimates. It may benecessary to carry part-way through this design phase achoice of two major alternatives, postponing the finaldecision until sufficient engineering and cost implica-tions of each allow a single design to be chosen.

6 6 . The overall procedure of planning, design andconstruction is illustrated in figure 8, where it can beseen that even with no delay for decision-making, andwith the procurement of funds starting as early as poss-ible in the design phase, the first works are unlikely tobe complete in less than 4 years. Therefore, as soon asthe decision to proceed with the chosen project designhas been taken, time can be saved by setting out asystematic programme of dates for the often protractedtendering sequence. Figure 9 shows a typical sequencein which 8 months elapse between the decision to pro-ceed and the point at which the main contract can besigned. A fuller set of guidelines for procurement isgiven in a brochure issued by the World Bank.3

2. TENDERINGPOLICY

67. Particularly for major port projects, it is advis-able to seek offers from several contractors in order tobe able to select the most advantageous one. Care

’ World Bank, Guidelines for Procurement under World BankLoans and IDA Credits (Washington, D.C., 1977).

should be taken to deal only with firms of high profes-sional standard and ample experience in marine con-struction work. Low-priced offers that may be submit-ted by less competent and experienced contractors canbe very costly in the final analysis, as difficulties anddelays may arise and claims may be made for additionalcompensation.

68. In general, it is desirable that one general con-tractor should be made responsible for all civil en-gineering works and for medium-sized specialized in-stallations such as generating plants, lighting equip-ment and not overly complicated mechanical equip-ment. Confusion can arise at the site if two or threecontractors are carrying out their respective taskssimultaneously, especially if the tasks are of a similarnature. Specialized installations, such as a grain silo orfacilities for a major bulk cargo terminal, require con-tractors specialized in the fields in question. Such ser-vices could be provided by a subcontractor nominatedin the prime contract. Civil engineering works con-nected with some special installations, such as founda-tions, may be left in the hands of the general contrac-tor. For large dredging works, a separate tender isalmost unavoidable. Civil engineering contractors can-not be expected to have the necessary costly and di-versified equipment.

69. In some developing countries there are capablelocal contractors of international standing who wouldnormally be pre-qualified. But it would be unwise torestrict tenders for large projects to local contractors,since the benefits of international competition and ofan access to a wide range of technical expertise wouldbe lost. The employment of local firms may be obtainedby encouraging foreign contractors to subcontract as

22

widely as possible to local organizations for less compli-cated works. Only for minor projects would it beappropriate to restrict tenders to local contractors. Inmany countries toreign bidders are required to enterinto a partnership with a reliable local firm.

70. For the construction of large port complexes,even the basic civil engineering works can be dividedinto a small number of separate contracts. The break-waters may well be built independently from workswithin the port area as there would be no danger ofmutual interference, and since the construction of largebreakwaters can be a difficult task requiring the fullattention of a contractor. Separate tenders will alsonormally be arranged for dredging and reclamation,which are usually very extensive in such big schemes.Nevertheless, for the sake of administrative conven-ience and simplicity a main general contractor may beentrusted with all or most of the construction work withthe understanding that, by agreement with the Govern-ment, he will enter into partnership with other firms oremploy subcontractors.

71. At an early stage, well-known internationalcontractors should be asked whether they are in-terested in the project and willing to submit offers at afixed date. If so, they should send pre-qualificationpapers listing their relevant experience and achieve-ments. Advertisements in professional publications orleading daily newspapers can supplement individualletters in order to reach a wider range of firms. Thecharacter and scope of the project need be only verybriefly indicated in the letters and advertisements.

72. Upon receipt of pre-qualification papers, a listcan be prepared of firms qualified to submit tenders. Atthis point the temptation to pre-qualify too man)’ con-tractors should be resisted. However, a proportion ofthose invited will normally not tender. The objective isto have sufficient tenders to obtain a broadly basedcomparison. Tender documents are then sent to theselected firms with a request to submit offers by a cer-tain fixed date. The tender documents will be the basisof the future contract. It is generally preferable to in-form each firm invited to tender of the names of theothers. Little purpose is served by secrecy in these mat-ters and there can often be a definite advantage inspeeding up the possible process of the formation ofpartnerships or consortia.

3. TENDER DOCUMENTS

73. A clear and full description of the projectshould be given, in addition to the technical. financialand legal conditions of contract. Only with sufficientunderstanding of the required port facilities, and reli-able information on local natural and labour condi-tions, can a contractor submit a realistic offer. Threemonths should be allowed to all bidders for preparingand submitting their bids, and each bidder must berequired to visit the site of the future work in order tobecome acquainted with local conditions.

74. Detailed conditions of tender, including condi-tions of contract, technical specifications of all works,bills of quantities, etc., usually form a volume of some200 pages. They must be prepared by a team of en-

23

gineers well acquainted with the drafting of such docu-ments. The International Federation of Consulting En-gineers (FIDIC) and similar approved associationshave standardized conditions of contract which will beof assistance in this task. This task is normally beyondthe capacity of an average port administration. and it isappropriate to retain a firm of consulting engineers forthe preparation of tender documents. This is a naturalcontinuation of the previous task of consultants whohave assisted in the planning of the proposed port facili-ties.

75. Typical tender documents consist of two parts:general information for the bidders, and detailed speci-fications of all works. The general information includesthe following:

(a) Practical data about the submission of bids, theclosing date, and so on;

(h) A full description of the project;

(c) Basic information about local conditions;

(d) A statement of the guarantees required (a smallbid guarantee (2-3 per cent of the contract value) and amore substantial performance bond or bank guaranteeby the successful bidder (lo-15 per cent of the full priceof works));

(e) The conditions of contract (standard form plusvariations);

cf) A bill of quantities in which the bidder has toinsert unit prices for each category of work;

(g) Questions concerning legal provisions, arbitra-tion procedure. the problems of contractor’s responsi-bility and modalities of payment are usuallv dealt within the conditions of contract. Price escala;ion clausesnoting adjustment provisions and ceilings should beclearly defined. It is very helpful to the bidder if astandard form of contract is used.

76. Arrangements may be included in the condi-tions of contract for advance payments of the contrac-tor for his mobilization expenses, which can be substan-tial. Heavy cranes, pile-drivers, bulldozers, graders,trucks, trailers and passenger cars, and possibly a dred-ger with auxiliary equipment, may have to be broughtfrom abroad at a high cost. Housing, storage sheds forbuilding materials and canteens have to be provided,which often require a special water supply and a smallpower plant: bidders should be asked for a separatequotation for such items. An alternative method, whichis not recommended, particularly for a large project,consists in requiring the bidders to include proratedcosts of initial expenses in their quotations of unitprices for the various works. The unit prices becomeartificially inflated by this procedure and excessive pay-ments will have to be made if additional work not fore-seen in original plans is to be performed, or if the quan-tity of work is at all higher than indicated in the bill ofquantities.

77. The second part of tender documents includes:

(a) A list of the equipment that the contractor has tobring to the building site and of temporary facilities tobe provided for his staff, the workmen and the super-vising team.

(b) Specifications proper, ti;at is, detailed descrip-tions of all things to be done by the contractor, thematerials to be used, their storage, handling, samplingand measuring, and the way in which various construc-tion activities should be organized. The written specifi-cations are supplemented by a set of basic drawings asan integral part of contract conditions.

78. It is a good practice to authorize the bidders tomake their own proposals for modifying some technicalconditions of tenders and to submit an alternative offerwith full design data, in addition to the mandatory offerin compliance with the tender documents. The moreexperienced contractors may be able to make usefulsuggestions for slight modifications of the designs or forthe use of different materials that may result in lowerprices without affecting the quality or character of theworks.

79. Price quotations must be made by the bidders inunit prices. For each item listed in the bill of quantities,the bidder must enter two separate figures, one for theclaimed unit price (per cubic metre, square metre, kilo-gram, tonne, etc.) and another for the entire item inaccordance with the quantity indicated. However, pay-ment is made in accordance with the quantity of workactually performed as measured by the supervising en-gineer and not according to the quantity originally esti-mated, as shown in the bill of quantities. A differentmethod of pricing is often used for items where thequantity of materials and the amount of work can beestimated accurately in advance, for instance, an officebuilding. In this case a lump sum price for each of suchitems should be entered in the bid, so that no measure-ments will be necessary after completion of the workbut only the usual control of quality of work and ma-terials. A similar procedure is used for prime costitems, for example, equipment specified in the con-tract.

4. BIDEVALUATIONANDAWARDOFCONTRACI

80. Bid evaluation has the purpose of determiningthe value to the authority of each bid and the determi-nation of the lowest evaluated bid (which may not bethe bid offering the lowest price). In addition to the bidprice, adjusted to correct arithmetical errors, other fac-tors such as the time of completion of construction orthe efficiency and compatibility of the equipment, theavailability of services and spare parts and the reliabil-ity of the construction methods proposed, should betaken into consideration. To the extent practicablethese factors should be expressed in monetary termsaccording to criteria specified in the bidding docu-ments.

81. A report on the evaluation and comparison ofbids setting forth the specific reasons on which the de-termination of the lowest evaluated bid is based shouldbe prepared by the authority or by its consultant. Theaward of a contract should be made to the bidder whosebid has been determined to be the lowest evaluated bidand who at the same time meets the appropriate stan-dards of capability and financial resources. After finalclarifications and discussions, the contract can besigned and unsuccessful contractors notified and bidguarantees returned.

5. SUPERVISION OFWORK

8 2 . The work even of a qualified and reliable con-tractor must be properly supervised to satisfy the in-terested government or port administration that every-thing is being done fully in accordance with theapproved plans. The first duty of site supervisors is toverify the quality of materials and work. Building ma-terials must be inspected before they are shipped fromtheir place of origin. The method of transporting them,their storage at the building site, and the cleaning andother treatment of materials in preparation for usemust be carefully watched. Methods of work and tech-nical operations such as the mixing and placing of con-crete should be supervised.

8 3 . A second function of site supervisors is to mea-sure the quantities of work performed and of materialsused by the contractor in order to determine theamount of periodical part payments. Usually, such pay-ments are made monthly on the basis of certificatessigned by the supervising chief engineer. Payments arecalculated on the basis of unit prices quoted in the con-tract, with the application of the price adjustment coef-ficient and the quantities measured by the supervisors.

84. The supervisor also has a role in providingguidance and, where appropriate, direction to the con-tractor and in helping to resolve difficulties. He is re-quired to explain the more complicated parts of de-signs, to supply additional drawings and to issue in-structions in case of doubt. He ought also to appreciatethat suggestions made by a contractor with wide experi-ence may be of great value, even though they may be atvariance with some provisions of the original specifica-tions. In such cases, provided that the variation is care-fully recorded and signed by both parties, noting theimplications both as to time and as to cost, the variationmay be accepted. Finally, the supervisor may have au-thority, under the arbitration procedure, to decide onmatters in dispute under the contract.

8 5 . To organize such supervision may be a simpletask for a relatively minor project but for a large pro-ject a strong team of supervisors is needed, since all theabove-mentioned tasks cannot be performed by a singleperson. Civil engineers, mechanical and electrical tech-nicians, surveyors, accountants and office staff areneeded for a large project, in addition to an experi-enced engineer as chief of the supervisory team. Thesepersons must have at their disposal appropriate officefacilities, living quarters and transport, all of which mayhave to be provided by the contractor under the condi-tions of contract. In addition, the team may have to callon specialized assistance from time to time.

86. It is therefore an appropriate practice to entrustthe task of supervision to the firm of consulting en-gineers which prepared the detailed plans and specifica-tions for the project. The firm’s staff are best ac-quainted with the designs and are thus in a favourableposition to offer guidance or direction to the contrac-tor. Few port authorities are able to provide for suchsupervision from among their own staff, but it would bevaluable to attach to the supervising team one or twoqualified port staff.

24

6. DESIGNANDCONSTRUCTTENDERS(TURNKEYCONTRACTS)

87. A different procedure may be used for urgentport projects. Instead of providing prospective bidderswith final designs and specifications, a small number ofhighly experienced firms is invited to propose particu-lars of construction. prepare specifications themselvesand submit them together with price quotations. A gen-eral description of port facilities. their character. sizeand general layout are supplied to the bidders, and it isup to them to select the best structural design and mostappropriate building materials. This kind of agreementis also known as a turnkey contract as the builder isexpected to design and to construct a complex of facili-ties in full operational order.

88. Advantages of the turnkey contract are two-fold. The first is considerable saving of time, as pricecalculations are made simultaneously with the prepara-tion of specifications in a single operation. Secondly,the interested port administration may receive a largervariety of ideas and designs from highly experiencedsources at a relatively small cost.

89. A well-qualified staff is needed by the portadministration for the preparation of basic planstogether with other conditions of contract, and later toevaluate the varying technical offers, particularly thedifferent specifications proposed, and to supervise theworks. Not many ports have a sufficiently competentstaff for this, so that consulting engineers may still beneeded. Although a potential saving of consulting en-gineer time exists, this is unlikely to be great.

90. To prepare such a design and construct offer isa difficult and costly task which can be successfully per-formed only by firms organized for both port planningand port construction. The number of firms invited tosubmit offers should be limited to not more than three,since otherwise the incentive for participation would bevery small. The high costs of preparing the bid wouldnot be justified by a small chance of obtaining the con-tract in the face of competition. It is therefore fullyappropriate in a design and construct tender to offer amoderate compensation for the preparation of offers,irrespective of the final award of the contract.

91. The design and construct method is more oftenapplied to work requiring very specialized technol-ogies, such as oil refineries, petrochemical plants oreven large grain silos. Nevertheless, it can also be usedfor more general port construction projects if particularcircumstances so warrant.

7. TENDERSFORDREDGINGAXDRECLAMATION

92. Conditions of contract for a major dredgingproject are usually standard amendments to the FIDICforms. It is not easy to determine in advance the quan-tity of material that is to be dredged or the exact natureof the soil. For purposes of payments, therefore. theformula for measuring the amount actually dredgedmust be carefully established. Conditions of tide andweather may seriously affect dredging operations andthe kind of equipment to be used. Tender documentsfor a large dredging scheme should be prepared with

particular care, and the data gathered during the fieldinvestigations discussed in chapter VII, “Civil en-gineering aspects”, should be made fully available tothe bidders.

93. The target depth of water to be achieved cannever be expected to be reached exactly by the contrac-tor owing to the very nature of dredging. A fair toler-ance must be allowed for in tender documents; and inany case the quantity of material moved can be deter-mined only approximately. Descriptions of the kinds ofsoil which will be found should be as accurate as poss-ible. The nature and the estimated quantity of eachkind should be listed in tender documents, togetherwith an indication of the degree of accuracy the esti-mate is believed to have. The classification of soilsshould preferably be made in accordance with the 1972Report of the Permanent International Commission ofPIANC;4 a different nomenclature may be misunder-stood by the bidders. The classification of rock mate-rials is less standardized, so that a detailed descriptionin the tender documents is essential.

Q. Participation of project planners

94. Since most of the routine work of implementa-tion is usually entrusted to consulting engineers, thelocal port planning team has the opportunity to concen-trate its attention on the continuing substantive aspects.Team members should follow-the progress of work toensure that the conceptions and designs are trans-formed into reality as technical facilities, each of whichhas a pre-determined function. Small errors and appar-ent imperfections can usually be corrected during theconstruction period.

95. When the newly built facilities become opera-tional, it is highly advisable for the port planners, or atleast a part of the original local team. to observe care-fully current port operations in order to see how vari-ous particulars of the design and layout affect the effi-ciency of the daily work. Observations of that kind,carried out for a certain period of time, will serve as amost valuable guidance for planning future facilitiesand for possible improvement of those just completed.

R. Project proposals

96. Documents which are thick are difficult tohandle and, while they are superficially impressive,they are less likely to achieve their purpose thansmaller documents. Many reports are deliberatelymade bulky by:

Printing on one side of the paper only;Using double line spacing;Attaching unnecessary reference material and statistics;Using heavy paper.

Reports of this type should be suspected since theyimply that the authors are relying more on the quantitythan the quality of the contents. A good proposal even

’ The Permanent lnternatronal Association of Navigation Con-gresses. 155, TUC de la Lol. Brussels. Belgium.

25

on a major project can be a thin, convenient document, authors as part of their terms of reference.as shown by the World Bank port appraisal reports.These usually do not exceed 25 pages of text and 40

9 7 . A standard layout for the presentation of port

pages of factual annexes and are printed in a formatproject proposals is given in the annex to this chapter.

which gives a thickness of about 6 mm. This criterionThe layout comprises the full contents for a major

should be made clear to both internal and externalproposal. For smaller propsals, only relevant sectionsneed to be completed.

ANNEX

STANDARD LAYOUT OF A PORT PROJECT PROPOSAL

I. SUMMARY

A short presentation of the essential facts from each of the follow-ing sections of the proposal, from a Eew words on the background tothe key figures of the analyses. For a major proposal this may be aslong as two pages, but for minor projects it should be less than onepage.

Il. BACKGROUND

This should be a brief recapitulation of the relevant parts of themaster plan where this exists. It will normally include the following:

1. National economic setting: national priorities, targets and fore-casts of key economic indicators that affect the transport sector.

2. Transport sector perspectives (both national and local): effects ofthe infrastruclure on the port; relevant investment plans; expectedtransport events.

3. Long-term traffic scenarios.

4. Long-term zoning plan.

5. Review of future projects.

This description should be limited to those facilities which play apart in the particular project proposed. It should give key facts,where applicable, on:

Organization and management;Operations and maintenance;Physical description of existing facilities;Users and level of existing traffic;Tariffs and present financial performance.

IV. DESCRIPTION DF THE PROJECT

This section should be able to stand alone as a clear statement tothe reader of why the project is proposed, what it consists of, how it isto be implemented and what impact it will have.

1. Objectives: the project objectives should be stated in terms of theeffect it is expected to have, for example, to enable the port tohandle containers effectively; to shorten the time for the overlandtransport of goods; to relieve congestion at the general cargoberths; or to improve the standard of equipment maintenance.Most project proposals will have only one objective.

2. Status: it should be stated whether the project is a part of a widerinvestment programme or master plan, or is a new requirement.

3. Description of proposed works [or proposed purchase of equip-ment, etc.): this should be a summary of all aspects of the pro-posed activity which are described in detail in an annex to theproposal. The headings under which this description should beorganized vary widely according to the nature of the investment,but will often include the following: infrastructure works (quays,surfacing, dredging, etc.); equipment procurement (cargo-handling and harbour craft); storage; services associated with themain works (utilities, administrative buildings, workshops, hous-ing); expropriation or purchase of land; technical assistance andtraining associated with the project.

4. Cost estimates: however tentative the figures, estimates of everyitem of cost involved in the project should be listed, preferablybroken down into local currency and foreign currency compo-nents. Today’s prices should be used.

5 . Financing plan where appropriate, depending on the stage of plan-ning: a statement of sources of finance, loan requirements, rate ofdisbursement.

6. Implementation: a description of how it is proposed to go aboutthe procedures of design, tendering, project management, pro-curement and construction, and an outline schedule for all theseactivities in the form of a bar-chart.

7. Impact analysis: statements on the checks that have been made toensure that there will be no unacceptable detrimental effects onthe environment, from the point of view of: fishing; agriculture;marine life (fauna and flora); local employmenr; urban develop-ment; leisure activities; and historic sites and monuments; and onany protective measures which may be necessary.

V. ECONOMK EVAL”AT,ON

Two subjects may be included here: (a) why the facilities areneeded; and (b) evidence that the economic evaluation is favourable.

In the case of a minor project, only the first item may be needed,since economics may not enter into the decision (the financial evalu-ation being the sole criterion).

Item (a) may consist of an explanation of such factors as: thepressure of demand on existing facilities; the deterioration of thelevel of service; the expectation of new demands.

The economic evaluation will be a full analysis of the economiccriteria and a demonstration that the project is being proposed at theright time with respect to the rate of growth of traffic.

The traffic forecasts should be summarized in this section, withreference to a detailed annex. The appropriate combination of alter-native scenario elements should be used, showing the sensitivity ofthe analysis to the key factors, which will be different for each pro-ject. For example, in addition to analyses for high and low trafficforecasts, analyses may be for two different rates of output, or fordifferent transit storage times, or for different numbers of majorequipment items, according to what is the most crucial for this pro-ject. It will seldom be possible to analyse the effect of all combina-tions.

VI. FINANCIAL EVALUATION

This is a standard presentation of the financial viability of theproject. For minor projects, a detailed financial evaluation will notnormally be appropriate, although a financial evaluation of the in-vestment is still required.

ANNEXES

All extensive tables and statistics should be placed in separateannexes at the end of the report.

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Chapter II

PLANNING PRINCIPLES

A. Port planning objectives

98. Many changes have occurred in the technologyof ships and cargo handling, and this development islikely to continue. A key principle in planning seaportfacilities, therefore. is that development plans shouldbe as flexible as possible to allow a prompt response tochanging demand.

99. Ideally, the facilities which a port providesshould be designed jointly with the ships which will usethem, the land transport and the port facilities at theother end of the route-that is, as part of an integratedtransport system. Unfortunately, this ideal can rarelybe achieved. It is possible only when the whole trans-port chain is under a unified management, for example,in the case of a specialized bulk chemical cargo terminalassociated with a local chemical plant, where the man-aging authority also controls the shipping fleet and theland distribution system: or again, in the case of a door-to-door container operation, where the carrier managesthe whole system.

100. In such cases, the planner should consider theport problem entirely in the context of the larger trans-port system of which the port is a part. The plannershould not forget that strategic and social considera-tions play an important role in the location of a newport. Within these considerations he should, however,encourage and assist the industrial planners to searchfor the overall economic optimum between, for exam-ple, ship size, rate of discharge, size of buffer stock andhinterland transport facilities. At this stage the plannershould also examine the technical specifications of theships proposed, to bring to light any technical problemswhich may arise in the port.

101. More often, such all-embracing plans will bevery difficult to draw up and implement since they in-volve many different interests. Insisting on an inte-grated transport plan as a preliminary to port develop-ment may then cause serious delay. Moreover, in thecase of a public berth to handle general cargo there willbe so many different users, each with their own physicaldistribution systems, that there would be little meaningto integrated, transport planning. In that case the portdevelopment planning can safely go ahead with the fol-lowing objective:

To prowde port facibties and operatmg systems in the nationalinterest ar the lowesr combmed CDS LO the porr and port users

102. To plan for such an objective demands a goodknowledge of the future customers and their probablecargoes, and is the traditional form of port planning. Itaims to produce the best plan for whatever traffic de-mand 1s placed on it without trying directly to influencethe form of that demand. Naturally any promotion

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activity in favour of the port, and efforts to attract traf-fic and increase its volume, should be taken into con-sideration.

B. The investment plan

103. Ports in developing countries should normallyplan on the basis of a continuing climate of growth forthe next few decades. The continuing expansion ofoverseas trade in the majority of developing countriesimplies a continuing expansion of maritime trade, andin order to serve a fully developed hinterland the extentof port facilities required may be several times greaterthan those existing at present. Clearly, in spite of theoffsetting effect of the introduction of the use of con-tainers and of import substitution policies, there aregrounds for believing that developing countries will ingeneral see a strong continuing growth of demand fornew or improved port facilities.

104. There will be technological and social develop-ments that necessitate the use of new types of facilitiesor different locations, for example, sites nearer deeperwater or at a newly planned industrial centre. Therewill thus be a break with the past and the need for anew development policy, independent of previousplans. But in many cases the build-up of demand will becontinuous. and the adoption of the new technologywill be gradual during a sequence of investments. Forexample, as described in part two, chapter IV, a multi-purpose genera1 cargo terminal may be implemented instages, each of which takes account of existing generalcargo facilities. In such cases it is advisable, both fromthe engineering and from the economic points of view,to ensure that the investments are in fact treated as asequence.

105. The master plan for each port should set thelong-term development strategy, and this in itselfshould indicate likely investment sequences. Beforetaking a decision on any one development project with-in the master plan, the investing authority should callfor comparative economic analyses of several variationsin the sequence of which it forms part. The major varia-tions which should be studied should include:

(a) Delaying capital investments by investing insteadin improved productivity (equipment, special installa-tions and associated training programmes);

(b) Improving existing facilities instead of buildingnew ones;

(c) Combining the first and second stages of a de-velopment programme into a single large project inorder to economize in construction costs and to avoid

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the interference in port operations which would resultfrom a second period of construction activity;

(d) The simple economic policy of investing in facih-ties one by one as the demand for them builds up.The first two methods should be employed to theextent possible, before investment is made in the ex-pansion of facilities.

106. The most appropriate plan will usually com-prise a mixture of all four of these possibilities, andtherefore mathematical methods of optimizing the de-velopment policy are not often likely to be of assist-ance. There is no satisfactory alternative to calculatingthe economic and financial results of each of the de-velopment sequences and comparing them in detail.This work of searching for the best sequence of de-velopments through which the port should pass on itsway towards a growth target, rather than merely find-ing the best configuration to handle a given traffic fore-cast, can be readily carried out in the form of a dis-counted cost and revenue analysis.

107. A major advantage of having studied an alter-native investment sequence is that at any time duringthe period after the initial investment has been commit-ted, it will be relatively easy to change the plan ascircumstances change, the requisite information beingavailable. This adaptability is an important feature ofthe continuing development plan, calling for the regu-lar updating of systematic traffic forecasts and the abil-ity to recognize and take quick account of suddenchanges in shipping services or traffic demands. Trafficforecasting is discussed in chapter III below. The prin-ciple to be established is that the port managementshould maintain a permanent ability to recognizechanges in demand and to re-assess the developmentprogramme. Steps which could be considered are:

(a) The setting up of small permanent planning andmarket research sections;

(b) The institution of periodical (e.g. quarterly orsemi-annual) planning meetings at which any new de-velopments are reported and possible action is dis-cussed;

(c) The incorporation in each development project,whether supported by national resources or by externalfunds, of the possibility of modifying it, if necessary, atany suitable stage of its progress;

(d) Ensuring that the economic, operational andfinancial calculations of each of the alternative propos-als are properly documented and stored for easy refer-ence.

C. Terminal design principles

108. Part two of this handbook gives methods ofcalculating the required capacity of a terminal to handlea given traffic demand. For these calculations, differentprinciples have been applied, depending on the natureof the different classes of ship traffic:

(a) For conventional break-bulk cargo, it is neces-sary first to ascertain the number of berthing-pointsneeded in order to keep ship waiting time down to aneconomic level;

(b) For container cargo, it is necessary first to deter-mine the area needed to handle the annual throughputwithout impeding the operation;

(c) For specialized bulk cargo, it is necessary first tofind the hourly rate of discharge or loading that isneeded in order to handle the ships in an acceptableperiod of time.

109. Although the starting point for each calcula-tion is different, the full method requires the joint studyof productivity, the number and size of facilities neededand the level of service to be provided. The relationshipbetween terminal capacity and level of service providedis a basic feature of all development plans, and is dis-cussed in the following paragraphs.

D. The problem of planning berthing capacity

110. If ships arrived in port with complete regular-ity, and if the time taken to discharge and load shipswere constant, it would be a simple matter to determinethe berthing capacity that would guarantee both the fullutilization of berths and the avoidance of “queueing”by ships. Unfortunately, such an ideal situation cannever exist. Liners, and more particularly tramp ves-sels, arrive in port as if at random. In addition, the timetaken to discharge and load ships varies considerablyowing to variations in the quantities and types of cargohandled, the way cargo is stowed and the cargo-handling rate.

111. This combination of a variable ship arrival rateand a variable ship working time means that a 100 percent berth occupancy could be guaranteed only at theexpense of a continuous queue of ships. Similarly, theguarantee that ships would never have to wait beforebeing able to berth could be given only at the cost ofextremely low average berth occupancies. Neither ofthese two alternatives is acceptable. What is required isa compromise between these two extremes.

E. Cost considerations

112. Port costs are made up of two parts:(a) A fixed component which is independent of the

tonnage throughput (including the capital costs ofquays, sheds, cranes, etc.);

(b) A variable component which depends on ton-nage throughput (including labour and staff costs, fuel,maintenance costs, etc.).As the tonnage handled at a berth increases, so thefixed component, when expressed as a cost per ton,decreases. The variable component, when expressed asa cost per ton, will probably remain fairly stable untilthe berth comes under pressure to achieve high tonnagethroughputs, at which point the variable cost per tonwill tend to rise owing to the need to use more costlymethods of cargo handling. Figure 10 illustrates therelationship between the port cost per ton and thethroughput. It can be seen that the port cost curve(which is the sum of the fixed and the variable compo-nents) reaches a minimum value when the rate of re-duction in the fixed cost per ton equals the rate of

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increase in the variable cost per ton (point A on thegraph).

113. Then there is the cost of ship’s time in port.This time is also made up of two parts:

(a) The time the ship spends at the berth;

(b) The time the ship spends waiting for a berth tobecome vacant.

FIGURE 10

Variation of port costs with increasing traffic

FIGURE 11

Variation of the cost of ship’s time in port with increasing traffic

Variation of total costs in port with increasing traffic

As traffic increases, the time ships spend waiting toobtain a berth increases. At high berth occupancies,this increase in ship waiting time is quite dramatic. as isshown in figure 1 I.

114. The total costs incurred by ships in port isfound by adding together actual port costs and the costof ship’s time in port, as illustrated in figure 12. Thetotal cost per ton curve also has a minimum point (pointB on the graph), but this minimum is achieved at alower throughput than that at which the lowest portcost occurs (point A). Port planners need to be awareof this most important point. Planning to minimize portcosts alone will generally result in an unsatisfactorylevel of service to shipowners which can lead to conges-tion surcharges and will not be economically accept-able.

115. The minimum total cost depends on the size ofthe various cost elements. The location of this mini-mum is dependent on the relative capital costs of shipsand of berths. Thus, in respect of break-bulk generalcargo ships, higher berth occupancies are economicallyjustified than is the case in respect of the much moreexpensive specialized vessels such as container ships,tankers and liquefied natural gas carriers. For thisreason figures 10, 11 and 12 do not have quantifiedscales. Furthermore, the shape of the curves and hencethe position of the minimum depends on the relation-ship between berth occupancy and ship waiting time,which is complex. Queueing theory. a mathematicaltechnique, can be used, but there are dangers in usingthe published tables based on this theory without anunderstanding of the assumptions involved.

116. To assist the planner in choosing terminalcapacity. part two of the handbook provides planningcharts which bring into play all the important practicalfactors. They include a sufficiently accurate relation-ship between waiting time and berth occupancy to en-able planners to find the optimum economic capacityneeded to meet a given traffic demand. The relation-ships are based on a distribution of arrival and servicetimes which corresponds most closely to typical condi-tions.

F. Berth occupancy

117. Care is needed in interpreting records on berthoccupancy, if this is to be used as a yardstick for futureplans, or for comparing the relationship between berthoccupancy and throughput at different terminals. Berthoccupancy is a measure of facility utilization and shouldnot be used as a measure of traffic demand unless theother main factors-resources used, productivi ty,berthing policy-remain constant, which is rarely thecase.

118. For example, a certain container terminal waskeeping monthly statistics both of berth occupancy andof the quantity of cargo handled. Examination of anine-month period showed an apparently inverse rela-tion between the two sets of statistics: as the figure fortonnage handled went down, the figure for berth occu-pancy went up. This seemed contrary to commonsense, and on further examination it was found that the

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higher berth occupancy figure was the result of conges-tion at the terminal, which slowed down ship turn-round and so caused the berth to be occupied for longerperiods, while tonnage throughput dropped. In thiscase urgent steps taken by the management to relievethe terminal congestion brought a reverse in the trend,with throughput rising again and berth occupancyfailing.

119. Although recorded data on berth occupancymay be misleading, berth occupancy rules-of-thumbcan be used in planning calculations where the produc-tivity target is clearly defined. A better procedure is, asin the planning charts given in part two of the hand-book, to obtain the figure for berth occupancy as anoutput statistic from calculations based on the otherfactors. Comparison with recorded figures can then beused as a check.

G. Waiting-time/service-time ratio

120. This ratio is widely used as a measure of thelevel of service provided by a terminal, as would seemlogical, for ships that have less cargo to discharge can-not afford to wait as long as ships that have more. It isusually considered that waiting time should be notmore than lo-50 per cent of working time. But this ratiois also misleading since it can improve (i.e. decrease) asservice time deteriorates (i.e. increases). As with berthoccupancy, the ratio should be used only when theother factors are constant. Better still, as shown in theplanning charts in part two of the handbook, the ratioshould be set aside and only the total turn-round timeused as a measure of the port’s performance. When theplan has been based on investing for the economic opti-mum, the waiting-time/service-time ratio is bound to bean acceptable figure, generally less than 30 per cent.

H. Planning for variations in traffic

121. It is not necessary to use complicated mathe-matics to demonstrate that a tardy port response to anincrease in traffic will lead to congestion which can beserious and long lasting. Supposing for example that aterminal can handle 60 ships a month, a 10 per centincrease in traffic, meaning a mere six additional ships amonth, is likely to go unnoticed for some months ifarrival rates are not carefully monitored. Unless actionis taken to increase the rate of working, there will be anextra 18 ships in the queue after three months. If theport management then responds to the situation by in-creasing the rate of handling ships at the port by 10 percent, and maintains this increased rate continuously, itwill merely stop congestion getting worse. There willstill be a permanent queue of more than 18 ships, andlong waiting times. In order to relieve congestion,much more must be done: if the rate of working wereincreased by 15 per cent over the original rate so thatthe port could handle 69 ships a month, it would stilltake a further six months to clear the congestion. Furth-ermore, under congested conditions improvements inhandling rates are extremely difficult to introduce andmaintain.

122. While emergency action can be taken in suchcircumstances, the possibility of emergency action isnot an acceptable reason for restricting investment atthe planning stage. There has been too little apprecia-tion in the past that many ports have been working withfar too small a margin of safety in their capacity.

123. Working with too small a margin of sparecapacity can have serious consequences not only whentraffic gradually increases, but also when there areshort-term surges in traffic, particularly as a port has atendency to be inefficient when it is congested. Theport may thus reach a position from which it cannotrecover without emergency action. For example, agroup of chartered bulk cargo vessels arriving alltogether can prevent general cargo vessels from usingthe berths, and their cargo can congest the port landarea. Consequently the facilities are unable to recoverto handle the average traffic after the peak has sub-sided. When the increased demand congests a port,work slows down and throughput drops. This is a strongargument for bringing into play more capacity when thedemand is high and less when it is low, i.e. having areserve of port capacity which is used only duringpeaks. Is there therefore a case for investing in somespare capacity and keeping it for emergencies? To ex-amine this problem the planner must ask what will bethe form of a traffic increase when it comes, how themanagement will find out about it, and what control theport management will have over the port’s reaction toit.

124. The traffic increase is most likely to take oneof the following forms:

(a) The introduction of a new shipping service or ofadditional chartered vessels;

(b) A gradual trend towards larger shiploads in anexisting service;

(c) More frequent calls by an existing service(through the placing of additional ships in the service-normally announced in advance);

(d) Exceptional calls, for example, ships divertedfrom a neighbouring congested port.

125. Another change which can have a major effecton the port without being recorded as a change in thelevel of traffic is a change in the manner of carrying thecargo. For example, a decision to transport grain inbulk can cause serious problems for a port accustomedto and proficient in discharging grain transported inbags.

126. The increase will be sudden when, for exam-ple, a new service forms a sizeable part of the totaltraffic of a port, when a major national planning deci-sion is taken-for example, to increase a building pro-gramme, with the resulting arrival of a series of cementcharter ships at a port, or when a large neighbouringport becomes congested and diverted traffic swamps asmaller port. Responding to a sudden increase onlyafter it has happened will usually be too late, because ofthe time needed for adjustment. When the change isgradual (either because it is a matter of a progressiveincrease in the size of shiploads or because an ad-ditional ship placed in a service accounts for only asmall proportion of the total arrivals), it may escape

30

notice unless traffic figures are being very closelywatched. Although accurate current statistics in factreflect the changes that are taking place. since the traf-fic level fluctuates about its average value all the time,an important trend can be concealed by the normaltrafhc variation. Consultations with shippers can be ofhelp in discovermg these trends or even in predictingthem.

127. There can be problems of short duration. Forexample. when the arrival of a priority passenger vesselprevents work on a ship-loader for one shift, the effectis not likely to be serious. The volume of export cargopiling up is not likely to occupy a large part of thestorage space available. With situations of slightlylonger duration. congestion problems may arise. Forexample, when importers take advantage of a low com-modity price, a large number of containers may arrivetogether but several weeks will probably be reqmred toarrange onward transport. The containers must stay inthe port area tor that period. and unless an overflowpark IS available, there will be congestion in the con-tainer park.

128. Longer-term traffic changes raise the questionof the proper level of port investment. Here, choosingthe amount of spare capacity which is available for usehut which is kept in reserve is a very serious decision.The balance between, on the one hand. investing inreserve capacity and thus keeping expensive facilitiesidle and, on the other hand. the prohability of facilitiesbecoming congested. will need to be argued out onstandard economic grounds. However. it must be rec-ognized that the uncertainty in forecasting is such thatmerely finding the economic optimum solution in rela-tion to the best forecast, and investing for that situa-tion, does not in itself constitute a satisfactory portplan

I. Co-ordinated contingency planning

129. In addition. an investment plan should makeprovision for flexibility in the port’s response to abnor-mal increases in traffic demand. It is strongly recom-mended that each port should have at its disposal acontingency plan for bringing additional reserve capacityof various kinds into use in a systematic. co-ordinatedfashion. The major facility needed to provide reservecapacity is additional berthing space. Investing in ex-cess modern berths and then delaying their commis-sioning is one option, but it will normally be too expen-sive to tie up capital-intensive berths in this way.Arrangements for overflow traffic should be cheap andsimple, for example, working to lighters and then tolighterage berths. This will result in higher cargo-handling costs. but the total economic cost per ton ofcargo will be less than if ships are made to wait forregular working.

130. The characteristics of such overflow, arrange-ments-low capital cost and high operating cost-areprecisely those of the older berths in the port, or ofmoorings. An effective policy can be to use regular newberths during normal conditions, keeping the old berthsand moorings in reserve for peak periods. This isadvantageous also from the productivity standpoint, as

concentrating the traffic as much as possible on the newberths will result in lower operating costs. It is true thatthe approach causes certain management problems inthe commissioning and decommissioning of the over-flow berths. since the switching of labour and facilitiesmay not he easy, hut the effort involved should heworthwhile.

131. There are several other forms of reservecapacity. Each of the factors that are mvolved in themeasurement of capacity (as shown in the planningcharts m part two of the handbook) could have somespare capacity in them. In the matter of ship workingthese factors are:

(a) The productivity in tons per gang-hour:

(h) The number of gangs allocated per ship;

(c) The number of days the berth is in commission;

(d) The number of hours worked per day.

132. In order to hold down unit costs, productivityshould always be as high as possible. Since there isusually a labour pool which is a cost to the port evenwhen idle. and cargo distribution in holds often limitsthe effectiveness of extra gangs. it will normally bewrong to keep any spare gangs in reserve. Days allo-cated to maintenance and dredging work should not beconsidered as a reserve since these activities are essen-tial to the long-term capacity of the berth, althoughsome flexibility in scheduling the work during periodsof peak traffic can he useful. Thus the main room formanoeuvre will be in the number of hours worked. Aport which is congested should work the maximum pos-sible number of hours within the limits of the availablestorage area and trained labour. The aim should be torevert to less than this maximum as soon as the conges-tion is cleared.

133. It is not a good policy for planners to baseinvestment analyses on the assumption that new facili-ties can be brought into operation and more intensiveworking methods introduced at one and the same time,Continual planning on the basis of maximum workingpossibilities and minimum economic investment willleave the port vulnerable to normal variations in traffic,The provision of reserve capacity should he given thesame systematic attention by port planners as is givenboth to the port development plan and to the pro-gramme of practical improvements in the use of ex-isting facilities.

134. Preparation of the co-ordinated port contin-gency plan consists of three main actions:

(a) Providing equivalent reserve capacities in allparts of the port system;

(b) Obtaining prior approval for the use of thesecapacities when certain situations occur or are about tooccur;

(c) Setting up an information system to report auto-matically when such situations arise or are about toarise.

The basis of any contingency action will be top manage-ment approval. although this approval will normally begiven only when the agreed indicators of demand havepassed the planned threshold.

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135. In addition to the use of additional mooringberths, increased overtime working and working duringnormal holidays, typical contingency plans may in-clude:

(a) Increasing handling facilities by hiring mobilecranes from outside the port;

(b) Increasing the average number of gangs per shipby hiring additional contract labour;

(c) Speeding up the repair of equipment by buyingspare parts manufactured locally;

(d) Hiring additional lighters and working oversideboth at moorings and on the outer ship’s side at berth;

(e) Opening up additional storage areas under cus-toms bond either within or outside the port;

cfl Hiring additional trucks and trailers for transportto storage areas;

(g) Giving priority berthing to high throughput shiptypes or ships with perishable goods.

J. The economic optimum

136. The main economic benefit of port investmentis the ability to reduce ship turn-round time. Conse-quently this is often the determining factor in settingthe economic optimum. There are two aspects whichmanagements should be aware of in making an invest-ment decision on this basis.

137. First, the immediate benefit from port invest-ment may accrue, not to the investing authority but tothe users of the port, many of whom will be foreign,However, in the long run, the port and the country as awhole will derive considerable benefit from the exten-sion and modernization of port facilities, It is also quitein order for the authority to invest in more capacitythan the economic optimum when it has good reasonsfor doing so, for example, in order to provide a deliber-ately higher level of service to the user as a promotionalpolicy to encourage the use of the port or to foster localindustry as part of a regional development policy.There is not likely to be any good case for investing inless than the economic optimum except where the rel-evant analysis was made on too narrow a base or wherethe decision authorities know that in a wider contextthe growth of the port should be restricted (for exam-ple, when traffic is to be diverted to other ports or othertransport modes).

138. The second aspect is the practical implicationsof the average ship waiting time. This measure of ser-vice to ships is not as simple as it may appear. A typicalcost-benefit calculation may show that the best com-promise between the cost of keeping ships waiting andthe cost of providing extra capacity is arrived at with aberth occupancy of 75 per cent for a group of five gen-eral cargo berths, and that this gives an average waitingtime of one day, compared with an average service timeof 3% days.

139. An average waiting time of one day has a speci-fic mathematical meaning, however. Taken over thelong term, this one day average waiting time for a five-berth group should mean that:

(a) Some 55 per cent of the ships arrived to find avacant berth and did not have to wait at all;

(b) About 10 per cent had to wait more than fourdays;

(c) About 5 percent had to wait more than 10 days;(d) For about 2 per cent of the time all berths were

vacant.140. Thus, for this economic optimum berth group,

for the greater part of the time there is no queue ofships waiting for a vacant berth, and for about oneweek in the year all five berths may be vacant. But inspite of this there will be times when the queue buildsup to cause ship waiting times substantially longer thanthe service time.

141. There are three lessons to be learnt from this:(a) A group of berths which rarely or never runs its

queue of ships down to zero is loaded above the econ-omic optimum.

(b) The normal situation at a group of berths shouldbe that immediate berthing is possible for a majority ofthe vessels arriving, but the fact that this is the case at agiven port does not mean that further investment can-not be justified.

(c) Shipowners are not entitled to use the excessivewaiting time of a few ships as an argument that the portis congested. Only the average of the waiting times of asufficiently large number of ships can be used in suchdiscussions.

142. The planner should also be aware of the factthat, even with the same rate of working and the samelong-term average traffic demand, there may be sub-stantial deviations from the average waiting time.There is always the chance of a higher than averagelevel of traffic persisting for a month or more, with aslow upward drift of waiting time and queue lengthwhich will be equally slow to clear. These upward driftsin waiting time can be counteracted by means of anoperational policy that reacts to pressure. For example,provision should be made for more intensive workingwhen required. Planning on the basis of the long-termeconomic optimum without allowing for contingenciesis bound to lead to short-term congestion.

K. Scheduled traffic

143. Where there are expensive facilities for hand-ling expensive ships, ensuring that the ship will not bemade to wait will result in a low berth occupancy whichwill not be acceptable to the port. The only way inwhich the berth occupancy can be increased withoutgiving an unacceptably high probability that the shipwill have to wait for a berth is to persuade ship oper-ators to schedule their arrivals more regularly. Specificdays can then be allocated to particular services, so thateach ship can be guaranteed immediate berthing if itarrives on time. Such arrangements generally allow acertain amount of latitude as regards arrival times, butwith an agreement that a vessel arriving outside theselimits loses its priority.

144. If several services can be persuaded to enter

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into such agreements. berth occupancy can be quitehigh. In such cases service-time and waiting-time re-lationships cease to apply and the berth requirementscan be calculated directly from the programme ofscheduled arrivals. When some days are allocated toscheduled services and other to general traffic, the cal-culation of requirements for the general traffic must bemade after subtracting from the total available berthcommission days those taken up with scheduled arriv-als. This calculation can be carried out directly with theplanning charts given in part two of the handbook.

L. Seasonal variations

145. When traffic studies show that there is a largeseasonal variation, the first action of the port plannershould be to persuade shippers’ organizations or indus-try sector planners to investigate the possibility of tak-ing steps to even out the demand. Ordering and stock-holding policies may be changed to smooth out thedemand fluctuations. New industries such as the pro-cessing of agricultural products into non-perishableforms may be introduced in order to reduce the peakdemand at harvest time. Another form of smoothingwhich can ahvays be used is to seek complementarytraffic for the terminal concerned during the off-peakseason.

146. Such means of smoothing out demand may beless costly in economic terms than the provision of therequisite port infrastructure, the associated physicaldistribution facilities and a reserve of labour at a levelsufficient to meet the peak demand but which remainunder-utilized for much of the year. The economic pen-alty of this under-utilization will be partially offset bythe low unit costs resulting from the efficient handlingof large quantities during peak periods. In each case theadvantages and disadvantages involved must be calcu-lated.

147. Unavoidable seasonal variation is bound tocause a substantial economic penalty which will be re-lated to the level of service the port gives to its custom-ers during the peak period. At one extreme. the portcan be designed for the average monthly traffic, whichwill result in long waits for ships and cargo during thepeak periods. Alternatively, facilities capable of hand-ling the peak demand can be provided, and their under-utilization during slack periods accepted. Neither ofthese courses will normally be acceptable.

148. The port management must first decide on anacceptable level of delays during the peak periods.Then steps can be taken to provide the necessary facili-ties. Care should be taken when calculating the costsand benefits in each season, and then combining them,not to overlook important operational considerations.In order to reduce investment, the provision ofmakeshift or secondary facilities for use during thepeak periods can also be considered. Although thesesecondary facilities will be less efficient and will giverise to higher unit operating costs, they will reducecapital costs. In the development of an existing portthere is a case for using the modern facilities through-out the year and using the less efficient facilities onlyduring peak times. Possibly such older facilities may be

33

switched to coastal or river traffic when not requiredfor peak working.

149. Seasonal fluctuations are often due to theoccurrence of seasonal peaks with respect to a smallgroup of bulk or semi-bulk commodities and it will beadvantageous to use specialized handling equipmentfor these commodities. If the level of such seasonalcommodities justifies the installation of fixed equip-ment which prevents the berth being used at othertimes. the specialized berth may have to be taken out ofcommission during the off-season. Normally, it will bepreferable to find a type of specialized equipmentwhich can be moved or dismantled during the off-season. This will ensure that the modern berths can beused throughout the year, while the older berths arebrought into action for handling genera1 cargo onlywhen the specialized handling installations for bulk car-goes are in use at the newer berths.

M. Capacity and traffic specialization

150. When determining the capacity needed tohandle the demand forecast, it makes little sense totreat the port as a single entity, however small the totalvolume of traffic. Each class of traffic must be ex-amined separately, and separate forecasts of annualtonnage. ship size, productivity and acceptable level ofservice must be made for each. The traffic must beassigned, either individually or in combinations oftypes, to the berth groups; then the appropriate capac-ity for each berth group must be designed. This princi-ple of dealing separately with different types of trafficruns throughout the methods given in part two of thehandbook, where separate planning curves are givenfor each main class of traffic.

151. Serious errors can be made by grouping intoone traffic analysis cargoes or ships with widely differ-ent characteristics. For example, in a given port it mayhappen that a number of roll-on/roll-off ships are usinga break-bulk group of berths for which the demand isfairly light. The overall cargo handling demand (mea-sured in berth-days required) will fail to justify addi-tional investment because the present average waitingtime is, say, only one-tenth of the average service time.However, these averages conceal the fact that the roiroships, with a quicker service time, are receiving an un-satisfactory level of service, a situation which cannot befully rectified by giving them priority berthing. Theremay be a good case for investing in a special purposeroiro berth, a matter which should be separately stud-ied. The special berth may bring added advantages suchas the possibility of scheduling the roiro services, intro-ducing special tariffs. etc.

152. At the planning stage, it should be considered,on balance, that the handling of dissimilar traffic at thesame berth group causes lower throughput than whenthey are kept separate. This question is complicated,for, on the one hand. specialization causes a loss offlexibility, as follows:

(a) A loss of berthing capacity through dividing theport and the traffic into two before allocating berths,i.e. a loss of berthing flexibility;

(b) A loss of the transit areas’ capacity achieved bymixing complementary traffic, for example, by alter-nating ships discharging shed cargo with ships discharg-ing bulk cargo for direct delivery while the shed clears.On the other hand, specialization gives the followinggains in consistency:

(a) A gain in service capacity in each facility whenthe segregation of the different classes of traffic meansalso a separation of high and low average service timesand of long and short ships, i.e. there is a gain throughgreater consistency of demand;

(b) A gain in average productivity since specializedfacilities can be made more efficient than general-purpose facilities;

(c) A gain through making fuller user of expensivewater areas, dredging costs, for example, being less forberths allocated to smaller vessels.

153. The balance between these advantages anddisadvantages of specialization will need separatejudgement in each case, but there is one general rule.Wherever a specific traffic on its own would providesufficient throughput for a separate specialized ter-minal, this should be the preferred basis for invest-ment. The planner should thus concentrate on identify-ing and separating traffic which will justify developingspecialized facilities. Where a certain traffic takenalone cannot justify a specialized berth, the plannermust revert to a multi-purpose solution. Certain trafficcombinations for which efficient multi-purpose ter-minals can be designed are discussed in part two,chapter IV.

154. It is difficult to quantify generally the extent towhich working mixed traffic reduces berthing capacity.The effect is greatest when the occasional large bulkship is worked at a berth normally handling smallergeneral cargo ships. In that case the disturbance to asmooth berthing sequence will be substantial. The plan-ning charts in part two of the handbook can be used byplanners to compare the effect on ship time of buildingtwo separate specialized berths or a two-berth multi-purpose terminal.

N. Flexibility and technical change

155. The flexibility which the contingency plangives in the handling of a fluctuating traffic demandshould be matched by flexibility in accommodatingtechnical change. The choice for a port strategy is clearin this respect. It is either to develop separate special-ized facilities for each major handling technique, or todevelop multi-purpose facilities capable of coping withany handling technique. Specialist facilities are themost efficient and economical when intensively used,but are uneconomical during the transitional build-upperiod. Multi-purpose facilities are more expensive toinstall and operate, but are likely to be fully used forthe whole period and so may be cheaper overall. Com-plete failure to plan for the new techniques will lead tothe most expensive result-new traffic being handledinefficiently in old ways at very high cost.

156. A specialized terminal will normally be justi-fied whenever a traffic forecast shows that there is suffi-cient demand, even if the remaining traffic leavesanother facility less than fully utilized. This principlewill apply to specialized terminals for cargoes such ascontainers, timber products, iron and steel and dry bulkcommodities. For example, a port currently having sixbreak-bulk berths each handling 150,000 tons perannum may be faced with a general cargo traffic fore-cast of 1,200,OOO tons, of which 50 per cent will becontainerized. If one specialized container berth isbuilt, its throughput of 600,000 tons will load it to areasonable level and justify the terminal. However, thiswill leave only 600,000 tons to be spread over the ex-isting berths, which are currently able to handle900,000. Nevertheless, the best policy would be to buildthe specialized berth and either to de-commission twobreak-bulk berths or, alternatively, to retain them asoccasionally used overflow berths.

157. The alternative policy in this example wouldbe to continue working mixed traffic at break-bulkberths and to build two more conventional berths. Thecost of the two conventional berths might well be lessthan the cost of a specialized container terminal.However, this policy should be clearly ruled out ongrounds of cost per ton and unsatisfactory service to thecontainer operators.

158. A far more difficult policy decision faces theport where the traffic forecast for a specialized technol-ogy cannot justify investment in a separate terminal. Inthe above example, if the forecast containerized frac-tion were only 20 per cent (240,000 tons), then the totalcontainer demand would not normally justify invest-ment in a specialized container terminal. Nevertheless,both container-handling facilities and additional break-bulk capacity are needed. The solution in this casecould be to build one extra multi-purpose terminalequipped with a combination of handling facilities asrecommended in part two of the handbook. The mainadvantage of this solution is that the multi-purpose ter-minal can be converted stage by stage from predomi-nantly break-bulk cargo to predominantly unitized car-go of various kinds, to conform with the changingtraffic.

159. Even where, owing to local circumstances, it isforecast that a port will continue to receive mainly con-ventional break-bulk traffic, the principle of flexibilityin design is still advisable. Where possible, operatingareas should be larger, depths of water greater, quayfoundations stronger and quay superstructures less per-manent than has been traditional. All these featureswill make it easier to adapt berths to accommodateships exemplifying the newer technologies, when theyeventually arrive.

160. It is not necessary to complete all constructionfeatures with an eye to the possibility of ships of largertonnage in the future, but only to build those elementswhich would be difficult to modify later. For example,at the time of construction the quay wall could be builtto a greater depth than would be necessary for shipscurrently expected, but the dredging programme forlarger future ships need not be carried out until theirarrival is more definite.

34

0. Principles of investment appraisal

161. This section summarizes the main principles ofinvestment appraisal as they affect ports. Both a finan-cial and an economic evaluation are generally requiredbefore a loan for a port investment project is approved.The former is essentially a computation of commercialprofitability and is not in itself sufficient; it is the econ-omic evaluation-the comparison of the social costsand benefits to the country-which determines whetheror not a loan is granted.

162. The two evaluations are identical in severalrespects:

(a) They require an evaluation of a succession ofcosts and benefits over the whole useful life of the pro-ject;

(b) They take into account the t ime-value ofmoney-whereby, because this year’s money can earninterest, it is of more value than next year’s money,which must therefore be discounted back to its present-day value in order to bring both on to an equivalentbasis;

(c) They use common criteria to evaluate invest-ments, namely one or more of the following:

(i) Average rate of return;(ii) Pay-back period;

(iii) Net present value;(iv) Internal rate of return;(v) Benefit/cost ratio.

However, the two evaluations differ with respect to thecosts and benefits included, since the port account isconcerned with direct costs and benefits while the na-tional government is concerned also with social costsand benefits deriving from trade promotion and similareffects.

P. Financial analysis

163. The financial analysis must evaluate the finan-cial viability of the investment and the impact of theinvestment on the financial health of the port authorityas a whole. The financial health of a port authority isusually evaluated by means of the following indicators:

(a) Forecasts (usually for a five-year period) of bal-ance sheet, revenue account and cash flow figures;

(b) Financial ratios of past and future accounting re-ports, the most commonly used ratios being as follows:

(i) Capital structure ratio (also named debt equityratio) shows capital and fixed liabilities as com-plementary percentages;

(ii) Liquidity ratio (or current ratio), i.e. currentassets divided by current liabilities;

(iii) Rate of return on average net fixed assets in use:i.e. net operational income divided by averagenet fixed assets;

(iv) Operating ratio, i.e. operational expenditure di-vided by operational revenue x 100.

164. In general, port authorities are required togenerate and retain sufficient income to:

(a) Carry out efficient operations;

35

(b) Maintain their assets in good working condition;

(c) Make a contribution to future investments forthe proper functioning and development of the port.

165. The data required for the financial analysiscome from:

(u) Estimates of the costs of the projected facilities;

(b) Previous financial statements of the port au-thority;

(c) Data recorded by the accounting systems;

(d) Past traffic statistics and estimated traffic fore-casts;

(e) Present tariffs of services from the port au-thority.

166. From this information, the following valuescan be calculated:

(a) Expected revenue from future traffic and tariffs;

(h) Expected operating costs;

(c) Investment costs and repayments;

(d) Cash flows;

(e) Financial ratios.

Further information on financial analysis is given inthe report of the UNCTAD secretariat entitled “Finan-cial management of ports”5.

167. The financial costs associated with a proposalare straightforward; they are the actual disbursementswhich the port authority will be required to make inconnection with the investment. They include the costof all preliminary studies and plan preparation, of land.construction and the purchase of equipment, and ofoperating the installation, including wages, fuel, spareparts, etc. The financial benefits are the additional rev-enue which will result from operating the extra facili-ties, as compared with the revenue which would havebeen received without them. The main sources of suchadditional revenue will be the port charges on ships andcargo.

168. Clearly, the results of the financial analysiswill be heavily dependent on the assumed throughput.Normally. therefore, evaluation should be done for arange of traffic growth forecasts. Moreover, the oppor-tunity should also be taken, while computing the finan-cial results, to calculate the consequences of differenttariff levels. This will provide the necessary informationfor a soundly based discussion of what would be anappropriate scale of charges.

169. The financial criterion for justifying a projectis that. with a realistic tariff, and after covering allcosts, including that of annual depreciation. the netrevenue earned in each year of operation will pay theinterest on loan capital and the equivalent of the in-terest foregone on the port’s own capital expenditure.The adoption of this financial criterion will thus lead tothe accumulation of the reserves that would be neces-sary for building facilities of equivalent value upon ex-piration of the amortization period.

’ UNCTADISHIW138

170. A purely commercial development by a portauthority that does not have national responsibilitiescan be justified on a financial criterion alone, but nor-mally both economic and financial criteria must beused.

Q. Economic appraisal

171. The economic evaluation is generally knownas the cost-benefit analysis, although strictly this termcould also be applied to the financial evaluation. Theeconomic evaluation is based on costs and benefitswhich differ from the financial transactions in a numberof ways. A fundamental characteristic of these costsand benefits is that they accrue mainly to the otherparticipants in the trade rather than to the port au-thority.6

R. Costs

172. The main resources for a port project in a de-veloping country are land, labour and foreign ex-change. The economic cost of each of these resources isits “opportunity cost” or “shadow price”. This cost isequivalent to the highest-valued benefit which is givenup by using the resources for this project rather than foranother project. In the case of land, a port may pre-viously have purchased the land needed for expansionat a cost, for example, of $1 million. The value of theland may have appreciated and, if it were released forbuilding offices, might be valued at, say, $5 million.Therefore, in the economic appraisal, $5 million wouldbe entered as the cost of the land. The opportunity costof labour is very low when there is no alternative usefulemployment. In areas of high unemployment, irrespec-tive of the wages which will be paid, the labour costsused in the economic appraisal will be very small andmay often be set at zero.

173. Foreign exchange rates in developing coun-tries are often fixed at arbitrary levels and consequentlythe demand exceeds the supply. In that case, the econ-omic cost of the foreign exchange component of theproject will be higher than the quoted exchange rate. Itis this higher rate, normally determined by a centralbank or ministry of finance, which must be used in theeconomic appraisal to bring the foreign exchange com-ponent on to a common base with other costs. Customsduties and other taxes on elements of a port develop-ment are not included in the economic costs since theyare purely a transfer payment from the port to the gov-ernment

S. Benefits

174. The major economic benefits of port invest-ment are:

6 A more detailed discussion of economic cost-benefit analysis isgiven in the report by the UNCTAD secretariat entitled “Appraisalof port investments” (TD/B/C.4/174).

(a) The transport cost savings made possible by theuse of ships which can carry the goods at lower cost perton of cargo (e.g. larger or more modern ships);

(b) The reduced turn-round time of ships in port.This is often the largest single benefit and it is essentialto estimate both the waiting time and the time at berth.Irrespective of the fact that this benefit often accrues inthe first place to foreign shipowners, it is now standardpractice to include it in the appraisal on the understand-ing that in the long run this benefit will filter through tothe national economy, for example, through lowerfreight rates;

(c) The reduced period goods spend in port and onships. This will free capital tied up in goods and thusgive indirect financial benefits to the country as awhole.

(d) The transport cost saving from the new routesfor goods to and from inland locations. This may, forexample, be due to the new port facility cutting out anoverland transport leg;

(e) The benefit derived from stimulating or makingpossible increased national economic activity. This ben-efit is often difficult to measure and should only beincluded when the activity could not take place if theport project were not undertaken. The benefit must beoffset against the opportunity cost of the resources usedin the increased activity;

cf) The benefit from making possible an increase inexports through, for example, providing facilities forlarger bulk carriers which will result in lower transpor-tation costs and allow the overseas price of the exportcommodity to be more competitive. For instance, newfacilities could permit an increase in exports of a givencommodity from one million to two million tons peryear, and at the same time reduce the price of trans-port. The savings on transport for the first million andthe benefit from the sale of the additional million areboth to be included.

T. Discounting

175. The first step involves the calculation, year byyear, of the net monetary flow expected from the pro-ject over its life. The net monetary flow in any year isthe difference between the benefits expressed inmonetary terms and the costs also expressed in monet-ary terms. The net flow is then discounted to obtain thepresent value. Discount tables such as that given inannex I (table II) can be reused. For example, with adiscount rate of 10 per cent, a net flow of $100,000 inthe fifth year of a project has a present value of $62,100since the discount factor is 0.621. This is equivalent tosaying that $62,100 would be worth $100,000 at the endof five years if invested at 10 per cent interest.

176. For commercial profitability, the correct dis-count rate is the market rate of interest. However, fornational economic profitability the appropriate dis-count rate is more difficult to define because of socialfactors. The choice of the appropriate rate of discountis a matter of national policy, on which the port plannerneeds guidance.

36

- --

U. The congestion cost pitfall

177. There is a pitfall to avoid when appraising aport investment which is planned to relieve or preventcongestion. With such an investment, the first additionalfacility will yield greater benefits than the second andsubsequent additional facilities. This is due to the verylarge reduction in congestion costs which is broughtabout by the construction of the first facility and whichsubsequent capacity increases cannot possibly match.This should not be used as an argument that this first,limited, investment is the most economic, since in thelong run this would amount to planning for a perma-nent and substantial level of congestion. To minimizethe overall costs of maritime transport, the correct levelof investment is that which provides the maximum pos-sible capacity while meeting the investment criterionwhich has been adopted.

V. Summary methods of evaluation

178. There are several methods of evaluation whichcould be used depending on the nature and magnitudeof the investment. A detailed discussion of thesemethods with worked examples is given in the report onport investments already referred to.’ The more com-mon methods used are:

(a) Average rate of return;

(b) Pay-back period;

(c) Net present value;

(d) Internal rate of return;

(e) Benefit/cost ratio.

The port’s evaluation of a project could take the formof any one of the above methods. For economic cost-benefit analyses, however, the more relevant tech-niques are the last three.

179. The average rate of return is an accountingdevice and represents the ratio of the average annualprofits after taxes and depreciation to the average netinvestment in the project (the original investment di-vided by two) or, sometimes, the original investmentitself. Since depreciation will gradually reduce thevalue of the investment during the life of the project tozero, the average investment is approximated by divid-ing the total investment by two.

180. The pay-back method literally means the num-ber of years required to recover or “pay back” theinitial cash investment. The basis of the pay-back calcu-lation is shown in figure 13, which is self-explanatory.

181. The net present value or NPV method takesinto account the time value of money. The discountrate specified must be used to discount all future cashflows to their present value. Summing these flows givesthe net present value of the investment. The criterionused in the NPV method is to accept the project if theNPV is greater than zero and otherwise to reject it.

’ “Appraisal of port mvestments” (TD/BIC.4/174).

37

FIGURE 13The pay-back period approach

lnatallat~on permd Pay-back perwd

182. The internal rate of return or IRR method isanother method which takes account of the time valueof money. The IRR is the discount rate that gives a zeroNPV, that is, the rate at which the present value ofbenefits equals the present value of costs. If the IRR ofa project exceeds the required rate of return, or cut-offrate, the project is acceptable; otherwise it is not. TheIRR method and the NPV method will give similaranswers with respect to the acceptance and rejection ofan investment proposal.

183. The benefit/cost rate uses the present value ofbenefits and the present value of costs and is obtainedby dividing the benefits by the costs. A ratio greaterthan 1 implies that the project is acceptable, while aratio less than 1 implies that the project is unaccept-able.

W. The four investment decisions

184. There are four distinct questions that must beanswered about a port investment proposal:

(a) Is the proposal in isolation economically andfinancially justified?

(b) Does it represent the best use of the availablefunds?

(c) Is the proposed level of investment in additionalfacilities the right level?

(d) What is the best point in time to make the invest-ment?

185. To answer the first question, the methodchosen depends upon whether agreement can bereached on what is the appropriate discount rate to beused. When all concerned are able to agree on a mini-mum acceptable return on capital. then the cash flowscan be discounted at this rate and the justification forthe project in isolation will best be on the basis of thebenefit/cost ratio or net present value. When it is diffi-cult to reach agreement on the proper discount rate,then it will be necessary to calculate the IRR. In somecases it may be advisable to decide to use the IRRmethod from the start simply to avoid introducingdoubt and delay into the project appraisal work pro-gramme.

FIGURE 14

Application of funds to a number of competing projects

,nterna, ---.--------I--?-------------rate Of , Cut-off rateWf”W -._ +-,--------------

II I, 111 I” Y “1 , vu “ill

III

186. In answering the second question, and in orderto find how to apply a certain quantity of funds toseveral projects, the most straightforward approach isto rank the projects in order of their NPV, and to stopinvesting at the project that is only just above the in-vestment criterion used or when funds are exhausted,whichever is the sooner. Unfortunately, there is a com-plication since there will usually be at least two dif-ferent types of funds, port reserves and borrowings,and different criteria may apply to each. However, asingle method can be used for both, as is shown infigure 14. Here, projects which are competing for thefunds are ranked according to their IRR, and on thehorizontal scale the point at which the port’s own fundsare exhausted and a loan will be required is also shown.In the case shown, the IRR of the first five projects isabove the required rate of return on the port’s owncapital, or cut-off rate, while the IRR of the sixth isabove this level but is not up to the higher level ofinterest required to be paid on loan capital, eventhough it would require a loan. An alternative would beto carry out project VII before project VI, whichshould either be deferred or, if this is technicallyacceptable, cut by one third. Ranking by IRR will notbe the only criterion, however; whether a project issocially useful, generates employment, or causes directrather than indirect benefits, will all be part of thedecision.

187. The third question is to choose the right levelof investment in facilities; for example, what is the rightnumber of berths to invest in at any time? The correctlevel of investment is found by progressively increasingthe number of berths until the NPV (or IRR) falls justabove the required value.

188. Finally, to find out when to invest in additionalfacilities, after a decision has been taken on the form ofthe project, the first year rate of return method may beused. The first year rate of return method involves acomparison of the first full year benefit with the cost ofthe project discounted up to the year of completion ofconstruction of the project, i.e., up to the year prior tothe year in which benefits will begin to accrue. If theratio so obtained is less than the discount rate, then theproject should be delayed by a year.

189. Where both economic and financial criteriaare satisfied, the following factors may govern the deci-sion between alternative solutions:

(a) Environmental impact: see table 12 entitled“List of site investigations” in chapter VII (“Civil en-gineering aspects”);

(b) Management impact: what new demands doesthe development place on top management? Is localstaff sufficient in number and quality to fill the keypositions?

(c) Organizational impact: does the new develop-ment demand a greater degree of autonomy or of flexi-bility which will be difficult to introduce? Does it re-quire changes in the internal structure and allocation ofresponsibilities?

X. Joint proposals

190. With two proposals, A and B, calculations willhave to be made for three cases, A alone, B alone andA and B together. If there is no interaction between thetwo proposals (with respect, for example, to trafficsharing, space sharing, storage requirements and land-ward access), A and B together will simply be the sumof A and B alone. When they interact, the joint pro-posal will need analysis in its own right.

191. Thus, when two interacting proposals are in-cluded in an investment appraisal, it will be necessaryto calculate costs and benefits both separately andtogether. Clearly, when three or four interacting pro-posals are combined in one appraisal, there will be agreat deal of work and considerable complications forthe decision-maker. However, this will generally bepreferable to artificially separating projects whichaffect each other. For example, the decision to buyfork-lift trucks for old berths will affect the decision tobuild new berths since the fork-lift trucks are alterna-tive ways of increasing capacity. If these two mattersare treated as separate investment projects then notonly will the calculation of the benefits of each be false,but the investment authority may not appreciate thatthere is a real and important choice to be made as towhere to put its funds to the best advantage. The auth-ority may then proceed with the new berths and decidethat it cannot afford the fork-lift trucks, with the resultthat the chance of a valuable short-term improvementin capacity is lost.

192. On the other hand, it is equally wrong to pre-sent a single analysis for what are in fact two separateproposals. This can obscure the fact that one may beprofitable and the other not. The economic justificationand financial viability of each type of facility must beinvestigated separately. Cross-subsidies cannot alwaysbe avoided, but before accepting that solution it is im-portant to examine methods of securing the financialreward of the economic benefit, normally by tariff ad-justment.

Y. Examination of uncertainty

193. When the full cost-benefit analysis and finan-cial analysis for the central forecast of each parameterhave been completed, the effect of uncertainty can bestudied by means of a simple sensitivity analysis. This iscarried out by repeating the analysis for variation in

38

each main parameter, taken one at a time, by anamount estimated to be a comparable degree of risk.For each of these values, the economic and financialeffects are recalculared. The ship’s time costs can bederived simply from the planning charts given in parttwo of the handbook. For example. for a project whichhas an IRR of 12 per cent. the sensitivity analyses mayshow the following:

C o s t offacihtles

P r o d u c t i v i t y

Trafflcgrowth rate

Economic hfe offacihtles

Costofship’stime

Number of commissiondays per year of facil-i t i e s

$ 10 million

soa tons pership day

5 per centper annum

20 years

$ 2,000per day

$ 12 millmn

20 per centless

2 per centhigher

per annum

15 years

$ 2500

270

14

10

15

10

194. The percentage change produced in the IRRby each parameter change allows the investing author-

ity to see the effects of changes in its estimates and totake all possibilities into account in its decision proce-dure. For example, it can be seen that a 20 per centreduction in productivity gives twice the change in theIRR (-4 per cent) as a 20 per cent rise in the cost of thefacilities (-2 per cent). A more rapid change in tech-nology which would make the facilities uncompetitivein 15 rather than 20 years has a 2 per cent effect on theIRR.

195. A useful variation is to invert the calculationand show by how much each of the variables wouldhave to change before the IRR fell to the minimumacceptable level, all other things being equal. For ex-ample, if construction costs would have to rise by 40 percent before the IRR fell below the acceptable (cut-off)rate, then local management might judge this anacceptable risk.

196. The planning charts given in part two of thehandbook have been designed with such sensitivityanalysis in mind. Since no calculations are required,each alternative value can be tested very quickly so thatit is possible to obtain ship’s time costs for a sensitivityanalysis without too much effort. Four of the six par-ameters listed above can be used as inputs for the plan-ning tables in order to arrive at the total cost of ship’stime. The other two (cost of facilities and economic lifeof facilities) can be directly inserted in the cost-benefitanalysis.

39

-- -.

Chapter III

TRAFFIC FORECASTING

A. Forecasting principles

197. The essence of port traffic forecasting is to findout:

(a) What kinds and tonnages of commodities willmove through the port?

(b) How will these commodities be packaged andcarried as maritime cargo?

(c) What ship types, tonnages and frequency of callswill this result in?Traffic forecasting requires a combination of commer-cial and economic knowledge; the mathematical tech-niques are of minor importance and can often be omit-ted entirely. Far more important is the need to bearconstantly in mind the very high degree of uncertaintyin any forecast, and to take steps to minimize the riskwhich this causes.

198. Any forecast of future trade will be uncertain,and ports are particularly vulnerable in view of theirlong planning time-scale and limited ability to influencedemand. All forecasts should be linked with the overallnational development plans. Furthermore, maritimetrade is going through a period of rapid change whichcritically affects the volumes and types of traffic likelyto use any port. Errors in forecasting can be serious,and the consequences of overestimating and underesti-mating are not equal. To over-build may add only a fewdollars, at most, per ton to freight costs, but to under-build may cause congestion leading to additional costsof $100 per ton.

199. Even when all precautions have been taken toreach realistic and well-reasoned forecasts, the remain-ing uncertainty usually produces a wide variation ofpossible levels of traffic when projected several years inthe future to the date of commissioning and beyond,and even greater uncertainty in the long-term masterplan. All forecasts are thus to be treated with caution.It is hoped that the actual traffic level will be closer tothe central forecast than to the upper or lower fore-casts, but the risk that it will not be is normally toogreat a one for a port management to accept. This ap-plies both to volume and to type of traffic. Thus therange of variation in the traffic forecast will usually bethe first concern of an investment sensitivity analysis ofthe kind discussed in chapter II.

200. The planner can do a great deal to minimizethis risk by searching for a design solution which isrobust-one that is a good investment under a varietyof possible future traffic. To do this he must be able toconstruct a number of different scenarios describingthese alternatives. The port management can reduce

the risk further by introducing an operational systemwhich can respond to changes in traffic, together withan information system which gives a clear signal whenthe response is needed.

B. Scenario writing

201. A traffic scenario is a consistent description ofthe whole of the future traffic likely to come to the portand the way it will build up. It assumes that the portdoes nothing to prevent the traffic arriving, but encour-ages it by providing reasonable facilities. For each car-go category, the probable volumes under different cir-cumstances and the possible alternative types of tech-nology that may be used in carriage and handling are allconsidered. Several scenarios are then drawn up, eachfully self-consistent, resolving any clashes betweenforecasts for different trades and permitting a reliableestimate to be made of the resources needed.

202. The scenario-writing team should include anoperational manager. It is an appropriate task for thetraffic manager of the port. The planner must consultthe traffic department early in the project and partici-pation of the traffic manager is a useful way of doingthat. Representatives of shippers’ and shipowners’ in-terests should also be invited to participate, if possibleas full members of the team. If the scenario-writingteam is formed entirely of local staff who have notrecently travelled outside the region, it would be advis-able for a small group to visit modern ports at the farend of their main trade routes to become familiar withpossible future developments.

203. It will not be possible for the scenario writingto take place until after the routine analysis of trafficdata, an examination of numerical trends and the mak-ing of simple projections. These are the data on whichthe scenario is based. But the team should be aware ofthe danger of reaching conclusions from extrapolationof past figures. For example, a team looking only atpast traffic figures may ignore the potential export traf-fic of mineral products from undeveloped mines whosepotential for production and export to overseas mar-kets have been definitely established. The possible highvolume of such exports will markedly affect port de-velopment.

C. Control statistics

204. It is the task of the traffic forecaster to provideboth a central trend forecast and also a system ofwatching at given intervals to see when the actual traffic

40

begins to deviate from this forecast. At, say. yearlyintervals “signposts” will direct the management eitherto carry on as planned or to change direction, depend-ing on the degree of deviation from the forecast. Thisapproach can be simple and very8 powerful. It requires:

(0) The regular collection of a small number ofessential traffic statistics to serve as a control;

(h) Giving a port manager (e.g. the head of the per-manent planning group. where this exists) the responsi-bility for reactivating the planning process when pre-determined deviations from forecast are reached.

20.5. Since any one port investment project maytake up to five years to complete, it is possible thatwithin this period the deviation from forecast will ex-ceed the acceptable level. In that case the planningprocedure should be repeated, starting from the statewhich had been reached in the project. Some form ofreadjustment will usually be possible even at a fairlyadvanced stage.

206. The most useful control statistics availablefrom the ship and shift records which should be keptare, as appropriate to each terminal:

(a) The total tonnage handled;

(b) The average ship turn-round time;

(c) The average tonnage loaded and discharged pership;

(d) The volume of special traffic handled at a multi-purpose terminal (i.e. the percentages of containersand roiro units, of bulk and bagged bulk shipments andof loads on pallets and pre-slung and pre-packagedloads);

(e) The percentage of ships with a specified type ofequipment such as shipboard cranes or stern ramps;

cf) The average ship length;

(g) The maximum draught on arrival and maximumship length.

With the exception of the last item, it is preferable touse the three-month moving average for the controlstat ist ics.

D. Combining the uncertainty in separate factors

207. Where a traffic forecast is being prepared froma detailed analysis of the factors involved, which arecombined (either by addition or by multiplication) toproduce the final figure, care has to be taken in dealingwith optimistic and pessimistic estimates of each separ-ate factor. Clearly, if there are three independent fac-tors affecting the forecast, then the probability of itturning out that all three have a high value or all three alow value is very small. There are simple statisticalmethods of calculating this overall probability. Thesemethods are given in annex II. section C, of the hand-book, and should be used where appropriate.

E. The forecasting procedure

208. A systematic procedure for carrying out a de-tailed port traffic forecast is illustrated in figure 15 and

the tasks involved are listed in table 6. For minor in-vestments. a review of the traffic forecast is advisable tocheck on the revenue expected; a simplified procedureas shown in figure 16 is reasonable.

TABLE 6

The forecasting procedure

I. Analyse past tralfic

I 1 Defme rouresiconference~. etc1.2 Choose cargo class~fxat,on1.3 Tabulate1.4 Calculate trends and analyse their causes1.5 Extract seasonal effects

2 Rewew marhet influences on trafhc and technologcal trends

2.1 Survey shtppera‘ opnuons. (public and private)2.2 Survey shlppmg compames plans

3. Estimate systematic traffic growth rates

3.1 GNP-hnked cargoes3.2 Special cargoes3.3 Regional/hinterland trends

4. Investigate expecred trafhc-Influencing events

4.1 Industry plans4.2 Agr~culrural plans4.3 Transport lmksltransit pohaes

5. Combine all mformation mto alternative growth and technologyscenarios

5.1 Identify principal scenarm themes5.2 Combine all data for each themeS.3 Remove numerical inconststencies5.4 Write scenarios

6. For each scenario, tabulate annual forecasts in each traffic class

6.1 Tonnages (weight tons)6.2 Numbers/sires of ships6.3 Seasonal effects

Welghttmeasurement ratio for storage purposes should also be re-corded for each traffic class.

209. The first step is to examine the existing trafficin detail, preferably on a year-by-year basis going backfor at least three years. If possible, the analysis shouldbe broken down in two ways: by country of loading ordischarge, and by major cargo class. This will providetwo tabulations such as those shown in tables 7 and 8.

210. The grouping of country flows into regionsshould be by loading and discharge areas on specifictrade routes. This is valuable because in general thesame kind of cargo from the same loading area will becarried in a similar way. It is advisable, also, however,to make separate records of the individual countryflows because this will make it easier to adjust forecaststo take account of political and other circumstances.

211. The grouping of traffic into classes should bedone in such a way that it will be possible to estimate,first, the volumes of cargo and secondly, the numbersand types of ship that carry it. There is no very easy wayto do this, and it is likely that the classes used willinclude a mixture of commodities and of ship technol-ogies. One method of classification is as follows:

4 1

F IGURE 15

The forecasting procedure

Define routes

Past trendsa n d

CDllSUltnationalDla”lVX

Consultindustrypbn”WS

Future traff ic events

Market surveyTonnages. technologv

Shippers Sh ipp ingc o m p a n i e s

FIGURE 16

Simplified forecasting procedure for minor investments2

Collect latest

*handl ing f iguresand update any

past trends

13 5y 6

Check that thespecif ic traff icfor which the Check with industry Deduce upper and Tabulate high and

investment is - planners f o r a n y 4 lower traffic - low forecasts for

proposed f i ts into recent changes growth rates the whole life of

the overall plan the investment

for the zone/terminal

A4

Check with port) users’ latest opinions

42

--

(a) All bulk traffic should be classified separately bycommodity;

(h) Bulk traffic in the same commodity should besubdtvided according to mode of carriage and handlingwhere this IS significant (e.g. wheat carried and dis-charged in bulk; wheat carried in bulk and bagged inthe hold before discharge);

(c) Non-hulk cargo should be subdivided accordingto mode of carriage (i.e. type of vessel carrying it). asfollows:

(i)(ii)

(iii)

(iv)

(VI

Conventional liner;

Specialized pallet ship (sideloader, etc.);

Roiro ship;

Cellular container ship;

Specialized semi-bulk carrier (for packaged tim-ber. iron and steel, etc.).

In addition, as an overriding principle. any commoditywhich is of particular importance locally-a principalcommodity-should be recorded separately.

212. Typically, this approach for a port in a de-veloping country will produce a list of, say 10 exportand 20 import traffic classes. Care must be taken withregard to the units used. It is unsatisfactory for develop-ment purposes IO record movement in revenue tons (orfreighr tons or porr tons) which are a mixture of weightand cubic measurement. All figures should he in tons ofgross weight (it is preferable for metric tons of 1,000kilograms to be used; but if this is not possible then theexact unit must he clearly stated). With regard to con-tainers, both the tonnage of the freight contents and thenumber of boxes (in TEUs, where a 40.foot unit countsas two TEUs) should be recorded.

213. A difficulty arises when vessels load a cargobelonging to a different traffic class from the cargo theydischarged, and possibly intended for a different traderoute. For example, a liner discharging manufacturesfrom Western Europe could load cotton for the FarEast; or, after completing a charter voyage to dischargefertilizer, a vessel might load bulk clinker for a near-seadestination. If these discharging and loading operationsare carried out at different terminals, the ship movingfrom one berth to another, then the solution is simple.Separate terminals or groups of berths must be plannedseparately. as explained in chapter II above, and theirtraffic must be considered as independent demands.Hence a ship which discharges at one terminal andloads at a different terminal must he counted as twoseparate ship visits for planning purposes. This is apoint where regular port statistics will not agree withthe planners’ data.

214. If the discharging and loading of cargo belong-ing to different traffic classes take place at the sameberth, then the solution is not so clear-cut. It will nor-mally be adequate to work with the average perform-ance figures for the mixed traffic, There are tworeasons for separating the traffic in the traffic statistics:

(a) To obtain a better estimate of the ship turn-round time and productivity:

(b) To enable separate forecasts of each kind of traf-fic to be made and to be revised in accordance withchanging conditions.

F. Forecasting cargoes carried by ro/ro ships

215. The variety of cargo classes carried on ro/roships makes it particularly difficult to convert commod-ity tonnage forecasts into shiploads. The majority ofro/ro ships in fact carry a mixture of the following cargoclasses:

(a) Rolled on and off:

(i) Containers on semi-trailers/chassis, with or with-out the prime-mover vehicle;

(ii) Container-like loads on road trailers or semi-trailers, with or without the prime-movervehicle;

(iii) Wheeled cargo (trucks, cars, buses, etc., whichare themselves the consignment).

(b) Carried on and off:

(iv)

(VI(vi)

Containers carried on and put down by largefork-lift trucks or straddle-carriers;Other unit loads such as packaged timber;General cargo carried on by fork-lift trucks andstowed in conventional holds, including a highproportion of pallets (general cargo may also berolled on board on trailers and then stacked);

(c) Lifted on and off:

(vii) Normal container operations on deck or in spe-cial compartments.

216. For development purposes, it will be difficultto determine what type of roiro ship will carry the fu-ture cargo. and hence the proportions in which theseseven classes are mixed will not be known. A simplifi-cation for statistical and forecasting purposes will be togroup them under four headings only:

(a) Containers: classes (i), (ii), (iv) and (vii) (it maybe noted that container-like loads can be measured inTEUs since a road trailer is roughly similar in loadcapacity to a container of the same length);

(b) Cargo canied by intermediate methods: class (v);

(c) Wheeled cargo: class (iii);

(d) General cargo: class (vi)

217. This grouping then allows the ro/ro cargo fore-casting to be part of the overall terminal forecast sinceall four categories will he forecast in total, irrespectiveof the ship type that will carry them. Only after prep-aration of the cargo forecast will it he possible to con-sider, according to the sea route, roughly how much ofeach of the four categories may be carried on conven-tional ships, on cellular container ships or on roiro ves-sels

218. The final calculation to determine the numberof roiro shiploads and thence the probable number ofship calls cannot be accurate. After discussion with theship operators concerned, a feasible and consistentsolution will he to specify one or more “standard roiroships” with a given part-load-capacity for each of thefour categories. The first category will be defined inship TEU capacity and the remainder in tons dead-weight capacity.

43

T A B L E 7Typical traffic forecast layout for various years

Liqurd bulk cnrgoesCrude oil ...............................Oil products ...........................Sulphu? .. . . . . . . . . . . . . . . . . . . . . . . . . . . .Molasses/vegetable oils ..............

Dry bulk cargoesC o a l . . . . . . . . . . . . . . . . . ............Iron ore . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Sulphur” ....... .......................Cementb ...............................Cereals ................................Other ..................................

Conminers and r&o loads’On cellular ships ......................On conventional ships ................On ro/ro ships .........................

Cargoes carried byinrermediate methodsPackaged timber .....................Iron and steel products ...............Other pre-slung and

palletized cargoes ..................

Break-bulk cargoesWheat in bags .........................Cement in bags” ...................Fertilizer in bags ....................Refrigerated fruit .....................Vehicles ...............................Machinery .............................General ................................

G. The market forecast

219. An essential part of a realistic port plan is theidentification of the potential users and the means oftransport being used for the various commodities. Thisshould take the form of a market forecast. In manyports it will be advisable to appoint a commercial mana-ger to carry out a continuous study of the market, andto make sure that this activity is closely co-ordinatedwith that of planning.

220. The aims of the market forecast should be todescribe:

(a) The present users:

(i) Who are they?(ii) What traffic are they offering?(iii) Who are the authorities making the decision

whether or not to ship via the port?(iv) What influences their decision?(v) What berthing, cargo-handling or other services

do they require?

(b) The potential users: a similar analysis;

(c) The ability of the port to influence the market:

(i) What users and traffic are likely to be capturedby port action?

(ii) What additional facilities would this demand?(iii) What will be the effect of raising or lowering the

port tariff?

221. These questions will be difficult to answer, andnormal commercial practice will obscure the truth.Nevertheless, a continuous effort to discuss them withrepresentatives of shipping lines and conferences, andwith shippers and inland carriers, will normally paysubstantial dividends and ensure that the port plan canbe developed to meet the true future demand ratherthan passively follow past trends. In view of the particu-larly rapid pace of change in ship and cargo-handlingtechnology, each stage in the analysis should ask speci-fically:

(a) What types of ship are being constructed for (ortransferred to) services which may affect the port?

(b) What methods of cargo handling will they re-quire?

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H. Rate of growth

222. In some service industries, such as telecom-munications, the demand may be limited only by thefacilities provided, so that any forecast may be self-fulfilling. There is an element of such investment influ-ence in ports, as modern facilities often generate com-mercial and industrial activities related to maritimetraffic, and these activities have a multiplier effect onthe development of the port. However, such influenceis generally considered to be small. A port whose in-vestment lags behind the demand will certainly holdback economic development, at least in the local re-gion; but a port that invests ahead of the demand mayonly slightly encourage economic development. In acompetitive situation, early and substantial port invest-ment can make a very large difference. However, it isnot normally appropriate for ports in developing coun-tries to engage in strong competition or in speculativeinvestments.

223. The fact that a congested port can inhibiteconomic development has an important implication. Itis not unknown for port planners to develop their ownestimates of future rates of national and regionalgrowth, tempering the central government’s growthambitions with the cold water of past experience. Thismay be understandable from the narrow point of viewof a port’s financial interests, since port managementnormally has to make sure that the future port is finan-cially viable, which it will not be if, for example, invest-ment has taken place on the basis of a governmenttarget of 11 per cent annual growth in GNP when overthe five years of a development project the actualgrowth has only been 6 per cent. The demand at thetime of commissioning of the new facilities will in thatcase be only 79 per cent of the forecast demand, anerror of over 20 per cent.

224. Nevertheless, this conservative approach by aport authority is not admissible. The past is not alwaysa reliable guide to the future. In the case mentionedabove, it would still be possible for a change to takeplace that might accelerate growth to the target level.The port management must accept that there may bewider issues involved and that its span of responsibilitydoes not include the revision of government targets.Instead, it must take two steps:

(a) Point out to central planners the implications of ahigh rate of economic growth for port investment at thetime the national plan is being formulated, so that thisfactor can be taken into account;

(b) Introduce review-points into each project plan atwhich developments in volume and type of demand aretaken account of; this will be part of the system of“signposts” mentioned earlier (see paragraph 204above).

I. Events

225. Important events which may affect the level ofa particular traffic should always be looked for, both toexplain past changes and to indicate future ones. Thesemay include political events, the bringing into opera-tion of new factories and refineries, the construction of

new inland transport connections, changes in the mar-ket price of a principal commodity and hinterland agri-cultural developments.

226. The difficulty of predicting future eventsshould not discourage the forecaster. Very often a re-examination of a forecast made earlier will show that avital event was not foreseen. This does not destroy thevalue of forecasting or mean that it was a bad forecast.It is impossible to do more than prepare a forecast thatis based on the best information available. Surpriseevents or circumstances can never be foreseen. Thepossibility that they will happen is a primary reason forthe flexibility in planning recommended in chapter IIabove.

J. Effect of the port’s own policies

227. The policies of the port will influence the fu-ture levels of traffic that use it. The users of a port areof two kinds:

(a) Captive users, i.e. the shipping lines, shippersand local industries which ship via the port becausethere is no economic alternative route;

(b) Non-captive users, i .e. those which, whileobliged to move goods in and out of the region, can useanother port within the region, or another mode oftransport, and secondly, those which could cease trad-ing activity with the region and so inhibit local econ-omic development.

Both types of non-captive user will react to the decisiontaken by a port planner. Thus a port by its own policiescan cause diversion of traffic to other ports or loss ofregional traffic. Normally, such questions should bediscussed at the regional planning level in terms of a setof objectives for the port.

228. One of the major ill effects which a port canhave on the traffic using it is to prevent the introductionof more modern or more economic ship types. For ex-ample, the arrival of larger bulk carriers can be pre-vented by the failure to provide deeper water. It isgenerally such changes which are in question ratherthan a gradual falling off in demand as costs rise or thelevel of service falls.

229. Only rarely, for example when there are com-peting ports in the same country, will an attempt toevaluate the more sophisticated traffic relationships bejustified. Such methods as demand elasticity estima-tion, analysis of effects of inter-port competition andanalysis of traffic creation sensitivity are difficult toapply because knowledge of shipping lines’ and ship-pers’ commercial intentions will not be adequate.Moreover, the probability that unforeseen events willseriously affect the forecast is always present. Never-theless, there may be occasions when the planner con-siders that the level of use of a certain facility will de-pend on the charges made for using it, and is at thesame time faced with the difficulty that the chargesneeded to pay for the facility depend on the level ofuse. In that case it is best to forecast on the basis thatcharges and unit handling costs will be comparable withthose applied at other installations of similar technol-ogy in the region and thus neither attract nor dissuade

4 6

traffic. Accordingly, the market research which isneeded before investment should be based on theassumption of a level of service and price roughly cor-responding to those at other installations. If. however,the new port facilities are to be based on improvedtechnology, for instance in handling dry bulk exports.costs may be considerably lower than those for olderinstallations in the region and the above approach can-not be used. The forecaster is then obliged to estimatethe relationship between charges and traffic.

K. Trend forecasting

230. The fact that over the last few years a particu-lar class of traffic has been increasing does not in itselfmean that the trend will continue. Trends can reversethemselves very quickly. Before projecting any pasttrend into the future, the planner should determine thereason for this trend, and the likelihood of its persist-ing. In most cases in developing countries, the reasonswill be one of the following:

(CZ) Traffic is directly dependent on the GNP;

(b) Traffic in a specific commodity or product hasbeen deliberately developed or run down (e.g. nationalself-sufficiency in a major foodstuff; development of anew industry or of mines);

(c) A gradual shift in regional centres of productionor consumption is occurring;

(d) A gradual shif t in t ransport technology orrouteing is occurring (from break-bulk shipment tocontainers; from maritime to overland transport, etc.).

231. If it is desired to find a traffic trend in a seriesof annual figures, simple methods are the best to use.Usually all that is necessary is to calculate an annualpercentage growth rate. or to plot quarterly figures anddraw in the trend by eye. When the trend is particularlyimportant and likely to persist. additional accuracy canbe obtained by carrying out a “least squares fit” pro-cedure to ascertain the form of the trend. This is astandard method given in text-books on statistics.

L. Seasonal variations

232. When a detailed traffic record-for example,monthly figures maintained for several years-is ex-amined, a regular. cyclic pattern may be noticed. Thisnormally results from a seasonal variation in demandfor, or production of, certain commodities. The con-tinuous trend line can be subtracted from the total toobtain the seasonal variation. There will still be super-imposed on this seasonal variation a random residualvariation, as shown in figure 17. Such analyses are like-

Separating a seasonal variation from a trend

Demand Total demand pattern = Trend + Seasonal vanstmn + Rendual variation

\-

2nd quarter 4th quarter

Time-

ly to be very much simpler and more useful if the trafficis divided into principal commodities, seasonal com-modities being kept separate.

M. General cargo traffic and GNP trends

233. Whereas specialized traffic is generally linkedto the development of a specific industrial sector, or toindividual events and policy decisions, general cargo-which in many developing countries consists predom-inantly of imports of consumer goods and generalmanufactures-is far more dependent on the trend innational wealth. An appropriate measure is the grossnational product. The figures for the GNP trend andthe government target should be taken directly fromfigures available at the national economic planningunit. Port planners should not normally engage in thisform of forecasting. It is, however, necessary to adjustthe GNP trend and to forecast for the hinterland devia-tion from the national trend.

234. For example, the hinterland trend may be be-low the national trend owing to a different rate ofgrowth in various areas or regions of the country. Thefactors causing this may be expected to continue unlessdefinite government measures are planned for the de-velopment period with a view to restoring the balance.Where regional GNP figures are available, useful com-parisons can be made between regional growth andgeneral cargo growth which will allow projections to beimproved.

235. Apart from deliberate regional developmentpolicies, there will be occasions when pressures thatbuild up produce trade shifts of their own accord. Onerecurring pressure is that caused when a central regionor capital city area grows to the point at which land andlabour costs become very high and industrial conditionsbecome less attractive. When that situation occurs, aport located in an area of less pressure, with good con-nections to the major internal markets, can expect afairly rapid build-up of industry looking for alternativelocations where conditions are more favourable.

N. Container traffk forecasts

236. Several principles should be observed whenpreparing the forecast for container traffic:

(a) The percentage of any trade which may becomecontainerized must be determined on the specific com-mercial and economic grounds for each case;

(b) There are no fixed lists of commodities which are“containerizable” and commodities which are not, anda wider range of goods is being shipped in containersevery year;

(c) Provision must always be made for a substantialproportion of containers moving empty;

(d) The average weight of cargo per 20-foot contain-er can vary from 5 to 18 tons according to the nature ofthe commodity.

237. There will be a significant trade imbalance,with import containers predominating, during the early

years of container operations in developing countries,since few of those countries will be able to providesufficient containerized export cargo to fill the availableimport containers. The number of empty containersbeing loaded in developing countries will therefore bevery high. Even so, however, a small number of emptycontainers will be unloaded there, for example,refrigerated containers intended for perishable exports.Thus, to the number of loaded units exported from andimported to the port, an appropriate number ofempties should be added. In the absence of other infor-mation, a figure of 60 per cent for export empties and 5per cent for import empties would be reasonable esti-mates.

238. Although for rough planning, overall averagesof cargo tonnage per container can be used, it is in-advisable to use a single blanket figure, since a tonnageforecast of 500,000 tons, for example, could be carriedin anything from 30,000 to 60,000 TEU containers.Wherever possible, the principal type of cargo to becarried (e.g. rice, general manufactures, refrigeratedfruit) should be determined and with the appropriatestowage factor, the figure for the average number oftons per TEU can be used, as shown in table 9. In theabsence of such information, it would be wise to planon the basis of a maximum figure of 12 tons per TEUfor imported general consumer goods in developingcountries.

239. When the class of cargo is known, the proce-dure for planning more accurately is similar to that ofcalculating ship loadings. According to the stowage fac-tors of the cargo, the maximum load can be limitedeither by the weight or by the space occupied. For plan-ning purposes the internal volume of a 20-foot contain-er can be taken as:

29 cubic metresor 1,024 cubic feet

This volume will be filled at the maximum allowablecargo weight of 18 tons only when the cargo stowagefactor is 57 cubic feet per ton (or 1.6 cubic metres perton). Commodities of this density are, for example,flour, potatoes and palm kernels.

240. Cargoes with stowage factors greater than 60cubic feet per ton will thus be limited by the physicalsize of the container, as shown in table 9, and thesetypes of cargo will usually be carried in 40-foot con-tainers.

T ABLE 9

Maximum weight per TEU as a function of stowage factor

6 0 1.7 1 7 . 17 0 2.0 14.580 2.3 12.69 0 2.5 11.6

1 0 0 2.8 10.41 1 0 3.1 9.41 2 0 3.4 8.51 3 0 3.1 7.81 4 0 4.0 7.3

4 8

Cargoes with lower stowage factors will be limited bythe maximum allowable weight per container (18 tons),and will he packed to a height less than the standard 2.2metres available in a container. They will all approxi-mate to an X-ton net weight. For cargoes with a lowerstowage factor. the use of half-height containers may bewarranted. However, it is not likely that this proportioncan be forecast, so that attempts to estimate the effectof half-height containers on stacking and productivityare not likely to be justified. (The principal dimensionsof containers are given in annex I).

0. Hinterland changes

241. The port’s local and wider hinterland can beexamined by studying the inland origins and destina-tions of a sample of consignments. The hinterland, andhence the port demand, can be affected by changes inthe following factors:

(a) Population and GNP;

(b)Regional development plans;

(c) Land transport developments;

(d)Coastal shipping and inland waterway develop-ments;

(e) Possible re-allocation of traffic to neighbouringports.

The planner should examine these factors when prepar-ing the traffic forecast.

P. Government trafftc

242. It should be possible to obtain information onthe traffic demands which central government depart-ments or other authorities have already decided toplace upon the port. The only forecasting task withrespect to such traffic is to obtain a reasonable estimateof its rate of growth. This traffic will probably consist oflarge quantities of individual commodities. For exam-ple. there may be a central decision to import a prede-termined quantity of fertilizer or cement. In this caseevery opportunity should be taken to convince centralplanners of the vital necessity of staggering the arrivaldates of a series of bulk charters. Very serious conges-tion can result from failure to appreciate this fact, andthe economic consequences of grouping the bulk ves-sels should be presented to the central planners.

Q. Trans-shipment traffic

243. The trend towards more rational route plan-ning, and the need to reduce the number of port callsmade by large, fast and expensive ships on a trunkroute, gives increased importance to the trans.shipmentfunction of a port. Not only do such changes introducea very different class of ship (feeder ships will besmaller and able to work in restricted draught condi-tions, and will have a high load factor) but there is alsoa variety of possible effects on the resulting trafficwhich is often overlooked.

244. For example, figure 18 shows two ports, A andB, each with its own hinterland demand for traffic of

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100,000 and 40.000 units per year respectively. Whenboth ports are served by the trunk route ship (case (a)),each has only the standard level of quayside activityassociated with its own hinterland traffic. In case (b),the trunk route ship stops calling at port B and its trafficis carried in a coastal feeder vessel. The level ofquayside activity is now:

Ar port A: The port’s own traffic plus double the trans-shipment traffic for port B (first discharging thetrunk route ship. then loading the feeder ship).

At port B: The same level of activity, but with smallerships.

In case (c) the feeder service to B is via land transport.The level of activity is now:

At porr A: The port’s own traffic plus the trans-shipment traffic for B.

At porf B: Nil.

245. Clearly, the demand for port services variessubstantially. After forecasting the traffic demand forthe port’s hinterland, the forecaster must then considerwhether it will be a main port or a feeder port for thattraffic, and what proportion of any feeder traffic islikely to go by sea or waterway, as opposed to road orrail. Handling facilities and storage requirements willboth be affected. Road or rail feeder traffic will, ofcourse, also place an additional load on the handlingand access problems of the land transport vehicles.

R. Technological changes

246. For each class of traffic and principal commod-ity, the planner must consider the possibility of changein methods of packaging. handling and storage and intypes of ship. These possibilities must be discussed withmajor shippers and shipping lines to determine:

(a) What decisions have already been taken;

(b) What long-term changes are likely:

(i) Assuming that the port plays an active role inproviding the necessary modern facilities;

(ii) Assuming that the port relies upon its existingfacilities.

If possible. discussions should also be held with themanagers of ports at the other end of major traderoutes, since the technological situation at the far endwill generally determine the change. This is one of thereasons for maintaining traffic statistics route by route.

247. The decision to introduce new technologies isnormally taken by the ship operator. Unfortunately,the time of the port investment decision is usually wellbefore a firm commitment can be expected from theshipping line to bring a specific class of ship to the port.This leads to great uncertainty as to the nature of thefuture traffic, and often the planner will be able only tosuggest that the general trend in technology justifies aparticular type of port facility. The port management’sdecision in such a case-for example; to invest in anexpensive container crane-will inevitably carry an ele-ment of risk.

248. The technological changes in shipping which

Ship /shoreoperationsa t A : 1 0 0 , 0 0 0

F~CURE 18

The effect of feeder services on quayside activity

Ship /shoreoperations

at B : 40,000

(a) Both ports on rrunk route


Ship /shoreoperations

at B : 40,000

(b) Port A mm port; pm B feeder pori linked by COU.WT or barge


Ship /shoreoperationla t 8 : N I L

(c) Port A main port port B feeder port linked by road/rai/

are taking place are discussed in detail in a series ofreports on the subject prepared by the UNCTAD sec-retariat.’ These changes take the form of a swing totraffic specialization and economies of scale, both onboard ship and in the weight of the indivisible load unitthat is lifted, rolled or floated off the ship. The planningimplications of container and other unit loads, or roll-on/roll-off methods, and of barge-carrying vessels areexamined in part two of the handbook.

S. Shiploads and number of ship calls

249. A forecast of the tonnages of each main cargoclass on each major route, which is based on the prob-

e “Technological change in shipping and its effects on ports”(TDIBiC.41129 and Supp. 1-6).

able trends in modes of carriage and cargo-handlingtechnology, can be converted, by means of the averageshipload, into the number of ship calls.

250. The forecast of the number of calls (the ship-traffic forecast), and of the related size of ship is impor-tant in planning for the estimation of the following:

(a) Required depth of water;(6) Required berth lengths;(c) Future productivity;(d) Turn-round time for individual ships;(e) The frequency of ship calls;fJJ The back-up areas required to handle the peak

shipload.251. It will be useful to discuss the prospects for the

consolidation of shipments with local shippers’ organ-

50

izations and with the shipping lines. Those bodiesshould be encouraged to consider what is the requiredand economic frequency of shipment, the size of ship-ment and the storage demand. on the expectation thatthere will be a trend towards economies of transportand distribution.

252. Both the trend analysis and the discussions willproduce a picture of the future which should be satis-factory for the purposes of ship traffic forecasting. Theforecast of the number of ship calls should be made inthe following two ways and if necessary a compromiseforecast arrived at between the different results:

(a) By dividing the figure for total cargo by that forthe average shipload;

(b) By ascertaining the number of calls directly frompresent records and the general trend.

253. It should not be assumed that there is a directrelationship between the tonnage loaded or dischargedby a ship at a port and the ship’s size. In liner servicesthe size of the cargo load taken on or discharged at agiven port is virtually independent of the ship’s carryingcapacity, except for home ports or terminal ports,where loads tend to be a larger fraction of the capacity.For regular short-sea feeder services or ferries, on theother hand, it is reasonable to assume full shiploads(allowance having been made for a minimum of 10 percent unused capacity in addition to the stowage factorlimitation). For bulk carriers it is not normally likelythat calls will be made for loads of less than 25 per centof the ship’s capacity, but it should not be assumed thatbulk tramp ships will have a regularly high percentageutilization at a single port. Loads varying between 25per cent and 75 per cent of the ship’s capacity are to beexpected, except with respect to major high-capacityterminals for the export, for example, of mineral ores,where the bulk carriers may be fully loaded.

254. The portion of the carrying capacity of a shipthat is loaded at a particular port is determined bywhichever is the smaller of the cargo available and theshipping space available. In addition, for a givenamount of space, there will be a minimum load whichwill economically jusify the call. This load will also de-pend on the pattern of calls made at neighbouring portsas part of a sharing of carrying capacity. In the case ofcontainer ships, port loadings have already settleddown to typical figures on economic grounds. The aver-age numbers of TEUs loaded or discharged per port ofcall are 400-500 on deep-sea routes and lo&l50 onshort-sea routes. These averages are relatively indepen-dent of ship size in both cases. The pattern of sharingout of carrying capacity is, of course, seriously changedon the introduction of feeder services.

T. Ship size

255. It is likely to be fruitless to try to find thefuture ship size on a route by looking for the relation-ship between size of ship and route length in existingservices all over the world. Such relations exist, butthey are so imprecise as to be of less value than a prac-tical operator’s opinion. For example. although there isa clear relationship between the grt of a given class of

roiro vessels and service distance. as would be expectedon economic grounds, there is a wide range of variationwithin this trend. On 1,500-mile short-sea services,ships vary from 2.000 to 8,000 grt and on 4,000-mileservices, they vary from 7,000 to 14.000 grt. Planningcannot be based on such broad trends. The plannershould study the existing port traffic and attempt toforecast future trends in order to determine this essen-tial factor.

256. An element to be borne in mind in long-termplanning for handling bulk cargoes is the tendency touse larger and larger ships for this purpose because ofthe economies of scale they afford. Consequently. suffi-cient water depth as well as width of turning basms andchannels must be ensured for the long-term develop-ment of bulk-cargo terminals. The relations betweendwt and the principal ship dimensions are reasonablysystematic and thus can be used in planning. They maybe found in the various chapters of part two of thehandbook dealing with the different ship types.

U. Evaluation of forecasts

257. Traffic forecasting is an art which places heavydemands on the planner. Outside consultants will oftenbe required to prepare the forecast: in this case. it isadvisable to check the forecast carefully to be sure thatthe consultants have fully understood the local needs.Apart from being mathematically correct and showinghow all the figures have been derived, the forecastshould pass the following tests:

(a) Has what is desirable to achieve been consid-ered, as well as what is likely to happen? What is desir-able can best be found from national economic targets.

(b) For each projection of a past trend, have thereasons for the trend been explained and has the futurecontinuation of each of these reasons been questioned?

(c) Have past records been analysed for seasonalvariations, and their causes identified?

(d) In each industry, and for each principal cargo.has a search been made for possible future events whichwill affect the traffic? Traffic-influencing events are:

(i) The opening, or major expansion, of mines,steel and cement works, refineries and otherprocessing plants;

(ii) The introduction of a new crop or of a newfertilizer policy;

(iii) The building of a new port;(iv) The opening or closing of roads. railways, can-

als and bridges;(v) The loss of an export market;

(vi) Changes in import licensing policy;(vii) Changes in the pattern of feeder and trunk

shipping routes;(viii) Changes of frontiers and other political events.

(e) If any forecast trends are linked to national econ-omic indicators, have these been adjusted for local de-viation from the national average?

cf) For each future trend. have possible constraintson growth been considered? Growth-limiting con-straints could be due to:

5 1

(0(ii)

(iii)

?Iv

Lack of transport capacity;Lack of storage outside the port;Lack of manpower;Competition for the same traffic;Environmental impact.

(g) Have alternative scenarios (future histories) ofhow the port may develop in the long term been writ-ten, and each converted into broad forecasts for eachclass of traffic?

(h) Has an attempt been made to gather, and then toreconcile, the views of shippers, shipping companies,and industrial planners? A valuable forum for recon-ciliation of views are commodity associations, cham-bers of commerce, etc.

(i) Has a check been made of whether any of thetraffic in the forecast is also claimed by another port? Ifthere is no national ports plan, there should at least bea reconciliation of the forecasts of neighbouring ports,and of their traffic shares.

(j) Have annual forecasts (both optimistic and pessi-mistic) for the whole life of the investment been tabu-lated for each class of cargo, showing:

(i) Weight tons of cargo;(ii) Numbers and sizes (dwt) of ships;

and recording seasonal variations and weight/measure-ment ratios for each cargo class?

(k) Are there any broad options or views of the fu-ture which the authors take for granted but which couldbe wrong and should be questioned? What are they?

258. For planners who carry out their own forecast-ing, the following dos and don’ts may be of help:Do talk to port users about their future plans, including

changes in technology and in cargo consolidation.Don’t forget that underestimates of traffic can result in

far more costly mistakes than overestimates.

Do listen to the views of the port traffic manager.Don’t believe that a past trend will continue in the

future without good reasons.Do spend more time looking for likely future events

than examining past trends.Don’t eliminate traffic from the forecast merely be-

cause its arrival is not definite. Present all the possi-bilities to the investing authority; it is up to them howmuch risk they want to take.

Do prepare separate forecasts for transit traffic toneighbouring countries. This traffic will have differ-ent procedures, charges and storage needs, and maydevelop differently from national traffic.

Don’t use advanced mathematical techniques to deduceaccurate trends from traffic records. The data is mostunlikely to be consistent enough or persistent enoughto justify the effort.

Do keep separate tabulations of transshipment traffic.It will be subject to different development from nor-mal traffic and can rapidly change.

Don’t waste effort trying to estimate the elasticity ofdemand for port services.

Do classify the cargo in enough detail to leave only asmall percentage under the final heading “other” or“miscellaneous”.

Don’t multiply together two uncertainties to produce abigger uncertainty. If you have to combine severaltraffic components, each with high and low esti-mates, use the method given in annex II.

Do periodically revise your ideas of what cargo is con-tainerizable, as this changes year by year.

Don’t guess at the average weight of cargo per con-tainer. Estimate this from your knowledge of thetype of commodity to be carried (see table 9 above).

Do maintain complete traffic records and introduce asystem of regularly checking key statistics for devia-tion from forecast.

52

Chapter IV

PRODUCTIVITY AND OPERATIONAL PLANNlNG

A. Pitfalls in estimating productivity

259. Estimating the cargo-handling productivitywhich will be achieved is a vital part of the plan for afuture port development. A mistake here can lead toserious investment errors. In considering the extensionof existing facilities, the planner must find out:

(a) What is the real productivity at present? Re-corded data are often inaccurate or misleading;

(b) How will this change with the new development?In theory, new methods should improve productivity,but in practice this is not necessarily the case.

260. There have been many cases of very poor esti-mates of future productivity, almost all bemg undulyhigh. This has probably been due mainly to two basicerrors:

(a) Contrary to a widespread misconception, an in-crease in cargo-handling productivity will not auto-matically give higher berth throughput. For example, achange from conventional break-bulk cargo handling tothe use of pallets should give, say, a 50 per cent in-crease in discharging rate, from 10 tons per gang-hourto 15 tons per gang-hour. But unless this is followed bya similar gearing-up of all subsequent activities (puttinginto storage, passing through customs, etc.), there willbe no increase in berth throughput and probably verylittle increase in ship handling rate.

(b) Productivity can go down as well as up. It is acommon experience in developing countries that at cer-tain stages of development there is a transitional periodduring which productivity falls.

261. For example, a port which has perfectedmethods of manual handling over many decades islikely to see a drop in productivity for a considerableperiod after a change to less labour-intensive mechan-ical methods. Discharge of wheat in bags by a large,skilled workforce can achieve tonnages per shift whichmay be difficult to match during the first year of opera-tion of bulk discharge equipment.

262. With respect to a new terminal, where thereare no local data to serve as a basis for estimating pro-ductivity, planners are forced to rely on performancefigures taken from elsewhere. Great caution is neededbefore adopting these. Often the figures are taken frominstallations with quite different conditions. Newmethods have generally been first introduced in coun-tries with a temperate climate, whereas the perform-ance which can be achieved in a tropical climate may befar lower. This is due not only to the human problem ofkeeping up continuous activity under difficult climaticconditions, but also to the direct effects of humidity and

53

heat on equipment, which can seriously reduce bothperformance ratings and reliability.

263. These local effects are sometimes compoundedby the optimistic sales information provided by manu-facturers of cargo-handling equipment. There is a ten-dency to quote performance figures on a short-run basisand to imply that long-run performance is merely aquestion of multiplication. This is seldom true of anymachinery, for:

(a) There may be other parts of the installationwhich cannot keep up with the mam equipment;

(b) There will be faults and breakdowns;

(c) There will be periods when the equipment is outof commission for routine maintenance.

264. These questions are discussed further in laterchapters where the main classes of equipment are re-viewed and some guiding figures are given. Neverthe-less, wherever possible, the planner should search forproven experience with the equipment in question fromports with similar conditions to his own. Assistance canalso be given by the UNCTAD secretariat and byorganizations such as the International Cargo HandlingCo-ordination Association (ICHCA) and the Interna-tional Association of Ports and Harbours (IAPH).

B. Rated and effective productivity

265. There are three basic elements in cargo-handling performance. The first is the rated productiv-ity, defined as the number of tons each gang. crane,shiploader, pump, etc., handles when it works for onehour without interruption. The second element is theinterruptions which tend to happen during any shift andthe consequent idle time that reduces the shift output.As a result of this idle time, the average hourly per-formance is reduced to what may be termed the effec-tive productivity. The third element is the manner inwhich gangs and appliances are used, for example, howmany are used per hatch and per ship, how many shiftsthere are, how much overtime working there is. Thislast element is termed the working intensity. It deter-mines how much total effort is used and this, combinedwith the effective productivity. produces the long-termperformance.

266. A major preoccupation of the planner will beto make a realistic assessment of the effective produc-tivitv from all the optimistic and arbitrarily chosen pro-ductivity figures which will be given to him. For exam-ple, many container terminal operators quoteproductivities of 700 TEUs per day, but a rigorous

UNCTAD analysis’ showed that, of 21 major containerterminals, only one, working so-called second- andthird-generation container ships, was able to maintain aproductivity of this order (749 TEUs per day) over sev-eral months, whereas at the great majority of the ter-minals, working with two gantry-cranes, productivityfell within the range of 300-500 TEUs per day.

C. Matching of operations

267. Some parts of the berth system are linked inthat every ton of cargo which passes through one ofthem has to pass through others. The most importantlinks are between the ship cargo-handling system andstorage, and, later, between storage and onward trans-port. The first pair of linked operations, unloadingfrom the ship and placing in storage, must be matchedon an hourly basis; otherwise one operation will have towait for the other, or goods will pile up in the opera-tional area and cause congestion. To find out if they arematched. it is necessary to know the hourly capabilitiesof each operation separately. But here lies the prob-lem: it is difficult to measure the one independently ofthe other, as any recorded performance will be that ofthe combined operation. For example, with regard tofigure 19, where it is known that for a break-bulk oper-ation the performance being achieved is 10 tons pergang-hour, it will be very difficult to find out whetherthis figure is limited by the gang in the hold which isfeeding the hook, or by the tractor which is transferringcargo to the shed.

268. Retrieving cargo from storage for onwardtransport cannot be matched with the placing of cargoin storage either on an hourly basis or even on a dailybasis so far as general cargo is concerned. Customsclearance and delivery formalities take time, and theirduration may vary considerably. But the capacity todespatch cargo from the transit storage areas mustmatch the flow of cargo from quay to storage on, say, aweekly basis; otherwise, transit sheds and open storageareas will become over-filled, and serious congestionwill result.

269. Such methods as those described in theUNCTAD report on berth throughput” if applied withrespect to break-bulk cargo early enough during theproject planning period, can serve as the basis both forachieving improvements in current productivity at theport and for giving planners a better idea as to what thefuture productivity is likely to be. It is advisable to bevery cautious-indeed, pessimistic-at the planningstage. Planning figures should be lower than the targetsthe operating staff set themselves and intend to achieveunder a new set of operating methods or with newequipment.

9 “Technological change in shipping and its effects on ports: theimpact of unitization on port operations” (TD/BIC.4/129/Supp.l),table 10.

” Berth throughput: Systematic Methods for ImprovingGeneral Cargo Operations (United Nations Publication, SalesNo.E.74.II.D.l).

FIGURE 19

Combined capacity of ship cargo-handling system and transfer system

270. The methods proposed in the berth through-put report can be used to check that the developmentproposal for a terminal gives a balanced throughputcapability. In the operations of a port, the various sub-systems function together so that the effectiveness ofone sub-system affects the operations of others. Thevarious sub-systems can be thought of as a series ofhighway sections of different widths, as illustrated infigure 20. The maximum throughput through this trafficsystem is determined by the capacity of the narrowestsection, B, which forms a bottle-neck. It is obviouslynot possible to increase the overall capacity by widen-ing any other section before making improvements tosection B. The only way to increase the overall capacityis to increase the capacity of section B to that of thenext largest capacity section, D. Then, if justified,further improvements in the total capacity will requirean equal increase in the capacities of both sections Band D.

271. The two major capital costs in many terminalswill be the berthing points, with their associated dis-charge equipment, on the one hand, and the storageareas on the other. Planning charts for both of these aregiven in part two of the handbook, but it is important toappreciate that the planning of these major elements isbased on the assumption that an equal level of capacityis provided also in the other stages of the operation, inorder to allow full exploitation of the two major invest-ments. For the import operation this will require par-ticularly:

(a) A design for the capacity of the system for thetransfer of cargo from discharge point to storage point;

(b) A design for the capacity of the system for theclearance of goods from storage;

(c) A check with sector planners as regards thecapacity of the onward distribution system.

D. Appropriate technology

272. The high cost of labour in many of the indust-rialized countries has justified the use of more ad-vanced techniques of mechanization and automation.In developing countries, different social factors usuallyapply. Moreover, the shortage of skilled operators and,even more important, of technicians to maintain ad-

54

FIGURE 20

Diagrammatic representation of a highway of varying widths

\‘-------J_/

vanced equipment, means that special care is neededbefore introducing such equipment. Simplicity andsturdiness are more important considerations than highhandling speeds, since the overall cost per ton withslower and simpler equipment can sometimes be lowerthan with advanced equipment that is out of service andrequires more costly support.

273. Some handling equipment demands an oper-ator workload and tempo which are excessive in a hotclimate and for the local labour physique. This will holdthe output down below what can be achieved in a tem-perate climate. In some cases the controls, for examplefoot pedals, are designed for persons of different phys-ique. a fact which makes the tasks very difficult andlowers output further. This can apply to fork-lift trucksas well as to more advanced equipment.

274. It is thus vital not only to make sure that pro-ductivity targets are realistic for the local conditions,but also that the suppliers of equipment can refer to itssuccessful introduction in similar port conditions else-where. Unless there is definite experience to go on,ports are advised to reject offers of untried equipmentand go for proven equipment only.

E. Productivity increases

275. Although the emphasis throughout this chap-ter has been on the danger of planning on the basis oftoo optimistic a forecast of future productivity, it wouldbe wrong to ignore the real increases in productivitywhich can gradually be achieved when specific changesare made, Measures for the improvement of productiv-ity that can be incorporated into a proposed project canbe divided into three main categories: those concernedwith human relations (labour and personnel), thoseconcerned with technical factors and those concernedwith administrative and procedural matters.

276. The first category will include all means forimproving the performance of each individual managerand labourer irrespective of existing technical condi-tions. Experience in many ports has shown that theproductivity of labour and of clerical personnel de-pends not only on their professional skill but to a greatextent on how far they are satisfied with the conditionsof their work, and whether they are really Interested inthat work. Specific measures may include:

(a) An adequate level of wages. commensurate withthe arduousness of dockers’ work, including premiumsfor performance above predetermined norms;

(b) Possibilities for promotion to more skilled jobs;

(c) Accident prevention measures, first aid stationsand well-organized health care;

(d) Canteens and rest-rooms near working areas;

(e) Adequate housing and recreation facilities;

cf) Training in technical skills and general educa-tion, and greater delegation of responsibility resultingin greater opportunities for initiative.

277. In the category of technical improvements thefollowing steps can be taken:

(u) The introduction of preventive maintenanceprogrammes, with properly equipped and staffed work-shops and an adequate supply of spares;

(b) The purchase of a set of pallets to be used forgeneral cargo;

(c) The purchase of additional tractor-trailer com-bines or fork-lift trucks for increasing capacity for thehorizontal movement of cargo;

(d) Technical training programmes for superintend-ents, the labour force and union officials, includingvisits to ports in developed countries.

278. The third category of measures, those for theimprovement of procedures and organization, includessome that are likely to bring about a considerable in-crease in throughput at a general cargo berth. Specificmeasures will include:

(a) Strict enforcement of the rule that individualconsignments must be removed from transit sheds with-in a limited period, normally seven or ten days;

(b) Simplification of old regulations and cumber-some procedures which can delay the smooth transit ofcargo through the port.

279. A forecast percentage increase in productivjtyshould not be taken as meaning that there will be anequivalent percentage cut in service time. The two arenot proportional. for

Serwe time =Total number of tons worked

Effectwe ship productlvlty

55

where the effective ship productivity is the number oftons worked per day at berth. At the maximum, a 100per cent increase in productivity would result in only a50 per cent decrease in berth time. The planning chartsin part two of the handbook can be used to determinethe effects of various changes in productivity.

F. Offsetting effects

280. Productivity improvements are often associ-ated with social and commercial factors which offsetthem. The gradual trend to shorter working hours, andthe resistance to working at night or at weekends inindustry in general, may become important factors inports of the future. Again, theoretical reductions inship service time due to increased productivity may beoffset by increased idle time as the ship operators mayhave a tendency to keep to a traditional fixed time inport.

G. Productivity targets

281. It can be misleading to give standard or evenaverage figures for hourly or daily productivity. Thereare many valid local reasons why one port, or one berthgroup within a port, may be able to achieve a figuremuch higher than another, and inter-port comparisonsof this sort are of no great value. Each port shouldcompare its current performance with its performanceof previous years and try to improve on that rather thanattempting to achieve apparently higher figures derivedfrom elsewhere, which may have been calculated on adifferent basis.

282. When the planning charts given in part two ofthe handbook are used, the figures entered for the tonsper gang-hour, the fraction of time worked and thenumber of gangs employed should all be taken fromfigures actually recorded. Where these are not avail-able, and particularly where a port has little experienceof the type of operation proposed, it is strongly recom-mended that operational staff pay a visit to a port ex-perienced in that operation, preferably in similar localconditions. The information they gather on such a visit,suitably adjusted to take account of local conditions,should be used as the basis for planning.

283. Nevertheless, in order that such productivityestimates remain realistic, the planner will want tocheck that the figure proposed is within the right range.Table 10 gives values which can be used for this pur-pose. The figures given are for a well-trained and moti-vated team working the average number of hatches foreach class of ship, and for a shift pattern which gives afraction of time worked (standard shift-hours per weekdivided by 168) of 0.6. The figures can thus be consid-ered in the nature of long-term operational targets.Their main purpose, however, is to act as a check-list toprevent over-optimistic productivity estimates. Higherfigures should not be used unless strong evidence existsto the contrary, and planners may prefer rather toadopt lower figures according to local circumstances.

TABLE 1 0Productivity check-list’

cargo elm

Conventional general cargo:On deep-sea routesOnshort-sea and coastal routes

Fully palletized general cargoPackaged forest productsBundled iron and steel products _.Pre-slung cargoesRoiro units _.COtUaiW3X

Torn per rhp-day

7 0 0500900

1 5002wo

9 0 02500

On deep-sea routes 450 TEUsbOn short-sea and feeder routes 275 TEUsb

Dry bulk:Loading ,. 7 0 p e r c e n t o f s h i p l o a d e r

rated capacity’Discharging 5 0 p e r c e n t o f u n l o a d e r

rated capacity’Liquid bulk S h i p ’ s p u m p i n g c a p a c i t y

(approximately 5-10 percent of dwt capacity perhour)

H. Operational planning

284. The preparation of an operational plan for anynew facilities is a key step in project planning. Thelayout, equipping and method of operation of cargo-handling areas must be known before either productiv-ity or cost estimates can be made. Particularly for newtechnologies or operating systems, it may be necessaryto visit other installations or to engage a specialist.

285. To encourage detailed operational planning,the planning charts in part two of the handbook call forinputs at a detailed level-number of gangs, tons pergang-hour, etc.-rather than at the overall perform-ance level, such as tons per day. The operational planfor a new development should give a reasoned figurefor each parameter needed in the capacity calculationsconcerned.

286. However, it will not normally be acceptablemerely to state the expected value for each parameterwithout considering two supplementary pieces of infor-mation: how is the present performance and why willthe future performance be different? These pointscould be tested where applicable by the following ques-tions:

(a) Has the impact of the traffic demand on opera-tions been considered?

(i) Ship call frequency and ship load;(ii) Seasonal variations;

(iii) Consignment size;(iv) Routeing (direct/indirect);(v) Storage characteristics;

(b) Has the full sequence of movement of the cargoin the port been specified?

5 6

6)(ii)

(iii)

(iv)

(S,,

Mode of transport for receipt/delivery;Facilities for loading/discharge of this trans-port;Type and volume of space needed for opera-tions and storage;Procedure and facilities needed for customsand other inspections;Method of tallying, sorting and weighing;Mode of transport for each movement in theport area;

( c ) Is the sequence of operations matched to the shipdischarge/loading rate?

(i) Work in the hold;(ii) Quay apron work;

(iii) Transfer to and from the quay;(iv) Stacking and retrieval;(v) Receipt and delivery;

(d) Are steps proposed to make sure that enough

trained manpower will be available?(e) Have the operational requirements for each of

the following been considered:

6)(ii)

(iii)(iv)

$;(vii)

(viii)04

(g(xii)

(xiii)(xiv)64

Pilotage;Tugs;Harbour craft;Navigation aids;Fire-fighting;Port security and policing;Dangerous material area;Equipment maintenance areas;Canteens;Rest-rooms and temporary living quarters;Minor repair facilities;Lighting (for night work);Communications (including ship to shore);Pollution control;Waste disposal.

Chapter V

MASTER PLANNING AND PORT ZONING

A. Port location

287. The early traditional ports were generally lo-cated close to or were part of a coastal city. Their func-tion was to serve that city and, secondarily, inland areasand towns. The traffic they handled was predominantlygeneral cargo. Even where there were principal exportcommodities, the quantities involved were smallenough also to be handled in break-bulk fashion (forexample, in bags). The commercial activities associatedwith the port, apart from warehousing, did not call formuch land area, and there was little industrial activity.Thus the city centre waterfront was an acceptable loca-tion for the old general cargo piers.

288. In the last few decades, many factors have in-fluenced the location of the port, changing the abovepicture almost completely:

(a) Commercial, warehousing and light manufactur-ing activities have been forced to move out of the mainurban area, both because of their increasing scale andresulting land needs, and because other demands forcity centre land have become too great;

(b) Industries have grown up which require exten-sive land area and easy access either to the port or tothe inland distribution system, or both;

(c) The tonnage of principal commodities has in-creased to the point where the whole scale of the oldoperation has been outgrown;

(d) This increase has made possible the introductionof bulk transport, which utilizes larger ships needingdeeper water and large transit storage areas, and alsorequires unencumbered landward traffic routes;

(e) The economies of scale have induced port plan-ning authorities to concentrate development at a singleport which services a considerably larger area than be-fore;

cf) The old concept of mixing port activity with thenormal life of a city population has been generallyabandoned on environmental grounds.

289. As a result, the preferred location of a modernport is no longer on a city waterfront. Existing cityports may continue to operate, but they serve only afraction of the total traffic, mainly the residual break-bulk cargo traffic for the local hinterland, together withcoastal trade and lighterage operations. The principaltraffic and the major proportion of the general cargotraffic, especially when unitized, must move to moresuitable locations. In developing countries, where uniti-zation is developing slowly, there may be the possibilityof continuing for a certain time to handle all the generalcargo in the old location, but if there is a considerable

volume of general cargo traffic, even if it is not unitizedit may need a new, more convenient location. In thegreat majority of cases, the industrial port activitiesmust be moved out of the urban area, even if only onenvironmental grounds. In fact, the new port may func-tion as a focal point for regional development and thusits location can be used to stimulate national economicgrowth.

290. A point to consider for ports contemplatingthe transfer of some activities to new areas is the possi-bility of offsetting the cost of new developments byselling or leasing the valuable city centre waterfrontland.

B. The master planning approach

291. The search for suitable locations for new portdevelopments and for extensions to existing ports willbe governed by the need for the following:

(a) Deep safe water at berthing points, and satisfac-tory approach channels;

(b) Sufficient land area;(c) A labour force;(d) Good access to road, rail or waterway routes.

This chapter considers the way in which the first tworequirements may be harmonized. The availability of alabour force to operate the port is a very importantaspect, as the economic and social costs of resettlingworkers is considerable. Engineering aspects of thewater area requirements are discussed in chapters VIand VII below. The inland transport connections arediscussed in chapter IX below.

292. These requirements form an early part of thework of master planning. The relationship between themaster plan and other, shorter-term port developmentprojects was described in chapter I, where it waspointed out that the master plan is concerned withpreparation for the long-term future. The emphasis ison setting a rational development framework intowhich successive construction projects can be fitted asthe traffic increases.

293. Master planners must look into the distant fu-ture and search for the most economic configurations,but the usual financial project appraisal techniques arenot appropriate at this stage of planning. The majorcriteria are industrial, social and environmental, withenough practical engineering study to ensure that thelong-term path chosen does not lead in a direction ofexcessive civil engineering cost. A principal considera-tion of the master plan will be to keep the port’s options

58

open as long as possible. For this purpose the plannershould give his main attention to preparing an overallprogramme of land use and preventing the authoriza-tion of the use of land for other purposes which wouldhamper the future development of the port.

294. When the port authority has responsibility forship repair facilities within the port area, these willform a special zone. Dry docks, slipways, etc., havetheir own land and water area requirements and willhave an important effect on the overall zoning plan.For assistance on this subject, reference should bemade to UNIDO.

C. Classes of port

295. It is important to consider a wide range ofalternatives before selecting one concept. A commonmistake is to become preoccupied with one proposaltoo early in the work. Nowhere is this more importantthan at the broad master planning stage. since there areopportunities here for influencing the whole course of acountry’s regional development. The conceptual stagestarts with the co-ordinated national port strategy, andhere the options open for a country with a long coast-line or many rivers are numerous.

FIGURE 21

Artificial harbour configuratiOnS

A. Projecting (dotted line shows original coastline)

B. Cut charnel and turmng basin

C. Y-cut channel

I). Parallel-cut channel

E. Additmn of arnficial port island to an ensting port

296. The main classes of port which may be consid-ered before deciding on a short list of site alternativesare shown in simplified form in figures 21 and 22. Inevery case the aim of the development is to providesheltered water with access to substantial areas of land.In that respect the artificial harbour formed by cutting achannel in land is particularly useful, and the Y-cutversion (figure 21, C) may be considered to give thepossibility of an optimum land-use policy. Such a Y-cutcan also be a useful elementary dock shape in morecomplex ports. In certain cases, however, such chan-nels have been found to amplify the wave pattern andtherefore careful model studies should be carried out.Where the facilities needed require more space thanwould be provided by any possible extension of theberthing length of a fully developed port waterfront,and water conditions permit, the formation of an exten-sive artificial island linked by a bridge, as shown infigure 21, E, offers a solution.

297. In the case of natural harbours, the estuarialport, such as that in figure 22, C, is likely to be the mostproductive of harbour facilities per unit of constructioncost, provided that dredging costs are not too high. Toavoid excessive maintenance dredging, this type of de-

FIGURE 22

Natural harbour configurations

A. Development of a natural harbour

i t - - - - - x - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - :

; I-------\ w----l----------.-:

B. Development of a natural offshore island

C. Development of a natural estuarial harbour

velopment requires particularly careful analysis of thehydraulic conditions, and the configuration chosen willnormally be most satisfactory when it reinforces thenatural regime rather than disturbing it.

D. Harbour configuration

298. A useful indicator of area requirements in portlayout design is the number of square metres of opera-

tional land needed per metre of quay. For a linearquay, this can be simplified to the depth of operationalland needed behind the quay wall. In earlier days, withsmall ships and low handling rates, the figure wassmall-often around 50 (50 square metres per metre ofquay), which included the areas required for the quayapron, sheds and rail track. This enabled long narrowpiers to be built inside a harbour to maximize quay walllength, as in figure 23.

FIGURE 23

Port layout to maximize quay wall length

______----------------------------

299. In this typical old harbour layout, maximumuse was made of the sheltered water. When the cargocarried per ship increased and productivity went up, theindicator increased quickly to 100 and then 200, so thatit was impossible to find enough operational land withsuch an internal layout. The reason for this is that a shipof twice the length will carry about eight times the ton-nage. It has more recently been fashionable to try toeliminate piers and basins entirely and to use only deepcorner areas and long linear quays, as shown in figure2 4 .

300. Although the layout shown in figure 24 is ex-cellent from an operational standpoint, it clearly usesfar more natural coastline and far more sheltered waterper berth than the layout shown in figure 23. Thereforethis construction is only likely to be economically feas-ible in rivers and estuaries where ample coastline andsheltered water are available. It would be very costly tobuild the harbour illustrated in figure 24 on a coastlinewhich needed artificial protection by breakwaters.

301. A simple layout is usually the most flexible forfuture development. The best way of providing theoperational land needed without wasting coastline andsheltered water is to build a pier-type configuration,but where the piers are far wider than is traditional. Asa rule of thumb it may be taken that a pier for any formof general cargo should not be less in width than twoship-lengths, as shown in figure 25, A, that is, about320 metres wide for an average operational cargo pier.For operational reasons it is advisable, where possible,to use the end of the pier only for minor harbour-craftand not as a berth. Prevailing currents and winds plusother navigational considerations will often make itpreferable to use a slanted or herringbone pier as infigure 25, B.

60

FIGURE 24

Port layout to maximize operational land area

FIGURE 25

Modern pier layouts

A Straight piers

B. Slanted or herringbone piers

E. The industrial port

302. Whether the port is to fulfil only its primaryfunction of transferring cargo between land and seatransport or to play a wider and more active role innational development is a primary question for the gov-ernment. On economic grounds alone, a clear case canoften be made for siting certain industries at the pointat which different modes of transport meet, since anyother intermediate location between the source of rawmaterial and the destination of the product will intro-duce an extra handling and buffer storage stage.

303. But the question is deeper than this. Portactivity constitutes a substantial industry in its ownright. The port employs large numbers of workers andtrains them in a varietv of skills which are transferableto other industries. It’is therefore a focal point for acomplete community and exerts a natural attraction forother industrial activity. Environmentally, it 1s alsolikely, prevailing winds permitting. that atmosphericpollution can be minimized when plants are located onthe coast. Thus, to plan a port without considering anindustrial zone is to lose a valuable opportunity ofstimulating regional development. The development of

a new port that does not include some industrial activitycan normally only be justified when:

(a) Urban pressure and/or environmental aspectsare a deterrent to further development;

(b) Geographical or climatic factors limit coastlineactivity to the bare minimum.

304. Strictly speaking, major industrial develop-ments which, for reasons of economy, are to be sitednear a waterfront, should be consldered purely asgenerators of traffic and supplied with port services inthe normal way. However, there will be arguments ad-vanced for such industrial areas to have their own portfacilities. This gives rise to the concept of a specializedindustrial port which is dedicated to that group of in-dustries and separated from the commercial port. Rela-tively isolated industrial complexes-for example,a mine and an ore-processing plant near a stretch ofundeveloped coastline-may justify the building of aspecial terminal close at hand to reduce land transportcosts. Large oil terminals are also often slted aw’ay frombuilt-up areas for environmental and safety reasons.However, in both cases, the accessible water depth islikely to be the governing factor, but the possibility oflong jetties or off-shore terminals gives conslderablefreedom in siting.

305. Such freedom to operate independently froman established port can be very attractive to industryplanners who may prefer to keep control over all stagesof their operation. Two notes of warning must besounded, however. First, it should be recognired that,in the long term. industrial complexes of any type tendto gather around them associated industries and com-merce. with a gradual build-up of local population andall the resulting land-use needs. It would be wise toforesee such developments before deciding on the loca-tion of the specialized terminal. Secondly, even thoughit appears that the terminal will be sited on an unde-veloped stretch of coastline, and it may not be possibleto imagine any alternative use, the long-term prospectsmay be very different. Coastline, which is a nationalresource, should not be given up to a user without areasonable revenue being collected. In such cases legis-lation may have to be passed to re-define the bound-aries of an existing port area to include the new term-inal, so that the port authority can collect revenue aswell as providing any miscellaneous services (mainte-nance of navigation aids. ship repair, tug assistance,fire-fighting) which it would be uneconomical to dupli-cate.

306. Major industrial development areas, asopposed to isolated industries should, if sited adjacentto a port, be provided with normal common-use portfacilities, and the temptation to give up coastline exclu-sively to special industry needs should be resisted. Gen-eral cargo needs should be routed through the normalport facilities, and only when specific industrial concen-trations reqmre specialired bulk terminals should theybe given a separate terminal within the enlarged portarea. The cargo-handling needs of the developmentarea will thus be brought fully under the planning andcontrol of the port authority, one of whose main con-cerns in master planning will be to exclude users of portland who do not need to be located in the port area.

6 1

Analyses have shown that the proportion of users whodo need to be located in the port area is sometimessurprisingly small. Such considerations can lead to arealignment of the proposed development area inland,rather than parallel to the coast, thus reserving themaritime community’s future freedom of action.

307. Since the secondary and tertiary industries addthe most value and aid regional development most,while the primary industries tend to contribute most toport revenue, a conflict of interests may arise in theallocation of land by the port authority to the variousindustries. Where the economic advantage of a particu-lar port land-use overrides the port’s financial objec-tive, a land-use subsidy by the government may beappropriate to compensate the port for its loss ofrevenue.

F. Free zones

308. The setting up of a free port, or a free zone forcommercial or industrial purposes, will have a majorimpact on the port’s master plan. This in itself may notalways be enough to encourage the extra activity, and acareful and objective market survey should be madebefore taking a decision on such a venture.

309. Free zones are areas where goods can be hand-led without passing through the national customsboundary. In the early days, such zones were predom-inantly for warehousing and trading, while more re-cently they have emphasized manufacturing, processingand assembly operations. Goods can be imported intoa free zone without incurring customs duties or quotarestrictions, and can be stored there indefinitely.

310. A UNIDO publication, concerning export-free zones” describes the concepts involved and coversthe physical planning of such zones. A report by theEconomist Intelligence Unit gives additional informa-tion on this subject12. The following salient points,taken from the UNIDO handbook, are mentionedbelow to provide guidance for preliminary masterplanning.

311. With the high cost of land development it ispreferable to carry out the project in stages. The initialstage should be small enough to show successful opera-tion, with all necessary services provided, in a period oftwo or three years.

312. Light industry is less likely to be attracted to aseaport area than medium to heavy industry, becauseof the advantages of airport zones for light industry.Firms which pollute the atmosphere and are thus re-stricted from locations near to residential areas mayalso be more suitable for location in a seaport freezone, provided that environmental effects are carefullyconsidered.

313. Areas involved can be of 200 hectares or up-wards when fully developed. Above this level excessivestrain may be placed on traffic movement in the area.As a rough guide, the built-over areas of a zone may

‘1 ffn,,&,& o,, Export Free Zones (Sales No. UNIDO/l00.3%12 ~,,~~~t,,,enr.. The Growing Role of Export Processing Zones,

Economist Intelligence Unit, Special Report NO. 64 (London, 1979).

occupy around one-third of the total area, the remain-der being necessary for roads, parking areas, servicebuildings, recreational areas, etc.

314. Normal principles of industrial zone planningapply, such as a preferred rectangular road layout withwell-lit roads for night-shift working. The customsboundary will rarely be smuggler proof, and it is prefer-able to rely on random examinations at checkpointsrather than high-security fences.

315. The daily power requirements for the averagemedium industrial development is around 1 kilowattper 10 square metres of factory space. Water require-ments, assuming no special process requirements (suchas dyeing), should lie in the range 135-365 litres perworker per day. As a guide to both employment oppor-tunities and water requirements, the approximate num-ber of workers per acre are given in table 11.

TABLE 11

Number of workers per acre by type of industry

Food, drink, tobacco .._. ._RefineriesPetrochemicalsOther chemical industriesLarge-scale shipbuildingSteel worksOther metal processingOther industries

4 01 1124

1 042

2013

G. Reclamation

316. Parcels of operational land are often gained bypumping or carrying dredged material from the water-side of a quay wall to where land is needed. The com-bination of both operations can give a lower cost, sincethe dumping of dredged materi ;I at sea is a costly oper-ation. The quality of the dredged material, however,must be suitable for reclamation purposes. This en-gineering activity can significantly change the masterplan possibilities.

317. By this means, an island, a sandbank, marsh-land or a tongue of land which would otherwise not beusable can be improved and given a berthing face andan operational surface. Small offshore islands can playan important role in a modern port, particularly in thedevelopment of bulk handling facilities for commod-ities which can be transferred to land via pipelines orconveyors without the need for an expensive causeway.A costly alternative, using advanced technology, is tocreate a complete floating offshore port. This, how-ever, is not likely to be a feasible solution for a develop-ing country.

318. Reclamation on a wider scale, for instance toprovide substantial industrial areas on low-lying land, isanother possibility. Again dredged materials can beeconomically used to raise the ground level. In suchlarge programmes the optimum solution will call for apre-planned, step-by-step approach. Such an area willusually need to be large enough for several industries,and its development as part of a regional policy will

62

normally be undertaken by a public authority which,for a port industrial zone. means the port authority.Various sites would then he leased on a long-term basisby the authority to industry. Unfortunately, there canbe little guarantee of successful leasing at the time ofplanning, since tenants will not start inquiries until thearea looks less like mere sandbanks or marshland andmore like a real industrial site, But once the site iscomplete, industrial demand is capable of building upvery fast and as a general rule such reclamation must bebeneficial to regional development.

319. Expensive infrastructure projects of this kindtake so long to complete that they have to be startednot merely well in advance of any project to build thesuperstructure which is to use them, but often beforethe need for the superstructure has even arisen. This isa vital aspect of port development and was probablyfirst apprecrated in the Netherlands where action of thiskind was a major factor in the success of Rotterdam.

320. When forecasts show that the growth in tradewill eventually necessitate very substantial new portfacilities, large-scale reclamation schemes deserveserious study as a long-term solution. The reclaimedland can reach out to deep water and so reduce dredg-ing costs. The whole complex can be planned to mini-mize adverse social and environmental effects. Thecomplex can become a combined residential. commer-cial and industrial development with properly plannedcommunications, including a commercial airport. Suchintegrated schemes are likely to become more neces-sary as development gathers pace.

321. The principle mentioned earlier of selecting aquay configuration in harmony with the existing confor-mation applies even more strongly to schemes for therecovery of large areas of tidal flats or marshes. In suchcases, not only can the major change in land/water in-terface cause environmental effects which may onlypartly be foreseen by model studies, but the approachchannels and berth faces may be subject to siltation andother adverse effects which can normally be minimizedby co-operating with the natural system.

H. Rationalizing port land-use

322. In parallel with the type of development dis-cussed above, where the extra land needed for themodern port is provided by reclamation, extension ordeveloping additional harbours. there is the need toexamine the port’s existing use of land and its generalwaterfront configuration. This examination is an essen-tial part of the master plan. since the rationalization ofthe configuration and of the zoning of land-use canrelease land for the increased operational port areasneeded in a modern port.

323. In a port which has grown up haphazardly intoa complex pattern of piers, basins and railway marshall-ing areas, a major rationalization needed is the simplifi-cation of the layout by closing berths made redundantby modern cargo-handling methods, filling in basinsand docks, removing rail tracks and resurfacing. Thiscan transform the port from a configuration which maylook rather like that of figure 23 to that of figure 22, A.The process is a gradual one. but such a long-term

6 3

direction of modernization should be set at the masterplanning stage.

324. A second possibility is the transfer of non-essential activities of the port area. Strictly speaking.the only essential port activity is the loading and dis-charge of ships and all else could be done some distanceaway, either inland or on a less valuable part of thecoast. A port of this type is an impractical commercialconcept, but the principle of removing activities inlandwhen port land runs out is a valid alternative in masterplanning. Long-term storage or warehousing with theassociated sorting and commercial activities may bestrong candidates for removal. The three necessarytechnical conditions for movement to an inland depotare: first. that the transport operation can be organizedeconomically; secondly, that the consignments arethrough-consigned on the shipping documents; andthirdly, that customs formalities are transferred to theinland depot. But in addition there can be serious or-ganizational problems, which means that only countrieswith a strong management base may find this solutionfeasible.

I. Zoning

325. Zoning is to some extent an art which, likearchitecture, involves many technical constraints. Theplanner should at each stage ask the question: “Whyhere and not there?“.

326. The way in which the different areas are fittedtogether will be a major factor in preventing futurecongestion. The most serious mistake to avoid is toallow long-term commitments to be made with respectto a piece of land which may later prevent the expan-sion of other areas and/or the access to them. A similarmistake is to allow land to be used-even when there isno long-term investment-for purposes which it willlater be too difficult to change for social and politicalreasons; for example, waterfront recreational areas.

327. All except the smallest or most specialist portsconsist of several separate terminals or groups ofberths, each handling one kind of traffic. The need todivide the port area into specialized zones has resultedfrom the demand for increased productivity at eachterminal. Where the volume of traffic is too small tojustify a separate terminal for each kind. or where un-certainty as to the form of future traffic does not justifya specialized terminal, the answer can be a multi-purpose terminal. In general terms the port will consistof the separate zones shown in figure 26.

328. At an early stage in the preparation of themaster plan, these zones should be clearly identified.Subsequently, the port authority should recognize theseparate nature of these zones and should both dele-gate specific responsibilities for their control to desig-nated managers and institute separate information sys-tems to collect traffic and performance statistics foreach zone.

329. The point at which it becomes economical toprovide a specialist terminal for a particular class oftraffic depends mainly on the annual throughput of thattraffic. The planner must determine the ships‘ turn-

FIGURE 26

Allocation of traffk to port zones

TOTALPORT

TRAFFIC

round times for the two alternatives, with and withoutthe specialized terminal. Then, according to the costestimates of the various terminals, the best develop-ment strategy can be selected.

330. Ports will require a number of service craftsuch as tug boats and pilot launches. Suitable dockingfacilities for these limited draught vessels should beprovided for at the time of master planning.

331. The relative siting of the zones in the port willdepend on the following factors:

(a) Water depth requirements for each terminal: thetraditional break-bulk depth of 7.5 to 10 metres will notbe adequate for deep-sea container vessels or dry-bulkand oil carrier vessels;

(b) Land area requirements for each terminal: forexample, the back-up area for a container berth will begreater than that for a break-bulk berth;

(c) The influence of prevailing winds: the siting ofthe zones should be such that dust and odours frombulk cargoes are not carried towards general cargoberths, passenger facilities or inhabited areas;

(d) Safety considerations: terminals for oil products,which must often be sited within the main port area,should preferably be located near the port entrance at areasonable distance from general cargo zones. Otherdangerous cargoes will need similar special zones sep-arated from other zones by a buffer area (see chapterVIII) ;

(e) Inland transport access: terminals for dry bulkcommodities should be sited in such a way that an easyaccess to the highway or railway network can bearranged, without the necessity of crossing densely in-habited areas;

m Compatibility of adjoining zones: apart from theconsideration of prevailing winds, care should be takento avoid placing zones together whose cargoes mayhave adverse influences on each other. For example, azone for grain and flour can safely be located next totimber or steel terminals, but not in the vicinity of fer-tilizer facilities;

(g) The traffic flow system: a zoning plan should notbe adopted before making sure that the routes for ve-hicles, rail-tracks, conveyors and pipelines fit har-moniously together. A plan which produces a largenumber of route crossings, bridges and flyovers must besuspect,

332. In considering whether or not to site individualtraffic separately, the possibility of finding compensat-ing import/export traffic should be checked. Examina-tion of origins and destinations of traffic shown in theforecast may suggest a combination of compatible flowswhich will help fill ships on their return voyages. Suchpossibilities should be discussed with the shipping au-thorities. If the different kinds of traffic concerned aresited together, ship movements within the port will beminimized and operational areas may be used moreintensively.

/ 6 4

333. Land-use management is made easier if land isunder the ownership of a single authority. The own-ership is secured either hy statute or purchase. Con-tracts or leases granting the use of port land should beconditional on the agreement to assist In the develop-ment of port trade. The length of security granted tothe occupier of port land should be the minimumperiod acceptable to him. Port-located industrial activ-ities must be controlled after they become established.to prevent them from changing into activities which donot require the use of marltime land.

J. Increasing revenue from large port expansions

334. The development cost of creating either largeareas of sheltered water or large areas of reclaimedland will be very high. It will be essential to exploit fully

the potential thus created so that the costs can be car-ried over a wide range of uses. For example. the bestplace for the breakwaters forming an artifical harbourmay be one enclosing a water area that is larger thanthat needed for mooring and access to berths. It wouldthen be advisable to look for ways, such as the con-struction of berth extensions or jetties. or the develop-ment of a fishing port or a recreational park. which willpermit the sheltered water to be used more fully andallow the costs and benefits of the breakwaters to beshared by a larger number of users. Similarly, on tidalflats it may be necessary to site the port facilities ad-jacent to a low water l ine that may be severalkilometres from dry land. The sea defence work, neces-sary to create the port may be more viable if it enclosesa large land area rather than merely a narrow accessstrip. The costs of the works can then be partially sup-ported by revenue from the dry land created by recla-mation.

ANNEX

MASTERPLANCASESTUDY: LOS ANGELES

A. Historical development of the port

1. Figure A. I shows the stages of development of the port from1872 to the tune of preparing a new master plan in 1975 The stagesthrough which the port has passed gwc an interesrtng example of theway m whxh a bay with some offshore islands may be developed Intoa large harbour with substantml waterfront and land areas It will beseen. however, that although the areas developed up to 1975 werevery substantnl, the master plan ior 1990 reqwes a “et mcrease of1.000 acres of land to serve the port’s needs

2 In the first diagram, relating to 1872. the port was handhng50.000 tons of cargo per year at small Jetties, mainly m the San Pedroarea. the approach channel bang to the left of Dead Man’s IslandTtus channel had been recently dredged to a depth of 10 feet at lowttde from Its previous depth of 18 inches

3. Between 1872 and 1908 a good deal of development tookplace. with a breakwater off the southern point and two short break-waters definrng the entrance channel to the mner harbour which wasbegmning to be used, this channel now being dredged to 15 feet. By1908 the breakwaters formed an outer harbour in which prolectingjetties were built Railways were constructed both to the wharves onRattlesnake Island and to the jetties in the outer harbour. The butld-up of cargo was very rapid, reaching 500,000 tons in 1888 and amilhon tons by 1908 Successwe dredgmg projects produced a depthof 18 feet at low tide throughout the whole oi the mam channel.

4 . Between 1908 and 1915 Rattlesnake Island was gradually builtout to a new harbour line, producing substantial warehousing andmarket areas. plus wharfage. The southern end of the Island. nowrenamed Terminal Island, was devclopmg as a substantml fish har-bour. Theeastern breakwater was removed to wden the channel. butDead Man’s Island still remained as an obstruction.

5 . By 1929. substanhal new mfilhng broadened Terminal Islandeven further. Dead Man‘s Island was removed and Reservation Pointwas reclaimed for federal use (to this day. and even in the 1990master plan, Reservation Pomt has been retamed for federal pur-poses wluch m fact are not connected wth the real objectives of theport) The required berthing spaces were achieved m typxal fashionfor the needs of vessels of that period by cutting slips and piers alongthe main channel waterfront During thts pernod, access roads werebuilt through to the waterfront and bridges and waducts were con-structed. A very substantml budd-up of traffic followed the commer-cial opemng of the Panama Canal. and the traffic doubled. redoubledand doubled agam during the ten years from 1920 to 1930, reaching apeak of 26 mllhon tons of wtuch 21 million tons consIsted of pet-roleum unporrs. The west basin on the land side of the harbour wasdeveloped. mcludmg substantial dredemg. wth all channels III theharbour deepened to 35 feet.

6 In 1935, the rmddle breakwater was built across the bay toprovide calm water and warehouses. ferry servxes and many otherfacdibes were stexhly developed.

7 The pattern of development from 1947 wac manly a specificresponse to the need for specialized facihties for Individual shippinglines, including. for example, a bulk grain termmal, speaal od ter-rmnals and a scrap meral ternunal. together wth new storage areasand a new customs building. The development plan in 1960 proposed15 new berths to be added durmg the next ftve years and an earlycontainer faciht). During ttus period the final dredging oi varioussand bars from the interior of the west basin was completed Privateboatmg began to develop with a boat marina, and yacht and smallboat anchorages

8 . The mam developments between 1967 and 1975 were a num-ber of container berths and the improvement of access roads Rolrofacilities were mstalled in 1974 and planning began for prowsion forhquid natural gas tankers.

9 . The resultmg port zonrng whxh was reached in 1975 is shownin figure A.2

B. Future requirements

10. At this point, in 1975, a major master plannmg study wascarried out to assess the long-term needs of the port and give a set ofguidehnes for the zoning and major port development which could, inthe immediate future, be translated mt” detailed developments.

11. The study found that for the port to remam competitive itmust be able to accommodate ships of greater size and draught.Vessels wth draught greater than the alsting range of 30 ft in themner harbour and 45 ft in the outer harbour and channel had beenvtsiting the port m increasing numbers. A large number of these hadbeen unable to enter the port at fully loaded draughts and had to belightened in deep water outside the breakwater before entry. It wasanticipated that by the year 1990 the average size of tanker would be250.000 dwt (draught 70-75 ft) and bulk carriers of 100,000 dwt(draughts at least 45 ft) Moreover, examination of the world con-tainer fleet showed that the port would not be able to accommodatecontainer ships larger than those of the so-called second generation.Finally, itquId natural gas (LNG) cryogenic carriers were expected,and these also had greater draughts than could be accommodated.Many tenants of inner harbour areas mchcated that they would need45 ft depth in order to reman. Thus there w% a definite need fordeeper water to accommodate mcreasing stup sxes

12. Secondly. the study found that there was a need for addnionalland. Land use analyses and cargo forecasts indicated a requirementfor a net additional I .OOO acres of land to serve the port’s needs by

65

FIGURE A.1

Past and future development of the port of Los Angeles, 1872-1990

Wilmington f+ 1

-

67

1990. The need existed t” increase the length of straght berths andthe area behind them for the space needs of tenants. Sites with thesecharacteristics were n”t available at the port.

13. Since deepening would naturally require a substantial dredg-mg programme, there was a unique and exceptional opportunity tosolve the port’s need for deeper water and addltional land in aneconomically, techrucally and environmentally sound manner. Tluswas to combme the current dredging programme wth a landfill pro-gramme. This possibility led to the proposal for a large landfill areaextending south east from Terminal Island.

14. The estimate of the requisne port capacity from the cargo-handling point of view was concerned rather wth area reqwrementsthan with the number of berthing points needed. The port plannershad found that any reasonable quay wall layouts such as those givenearlier in this chapter (see figures 21 and 22 above), must providesufficient berthing points when the area behind them provided thespace needed for typical annual throughputs.

15. The individual z”nes of the port were examined in detail butthe preliminary cargo flow projection looked at the demand on theport considered as a whole. Figure A.3 and table A.1 show the broadlong-term forecast to the year 2000 broken down by the malor cargogroups. These forcasts were developed using standard techmques asdescribed in chapter III above. Figure A.4 dlustrates the magnitudeof the increase between the 1973 actual figures and the 1990 projec-tions. The next stage was t” c”nvert the commodity flow forecastsinto land area requirements; straightforward land use coeff&ntswere used, relating the t”ns per year throughput figure t” the numberof acres needed. as is done for the existmg situation m table A.2.There was a great uncertainty regarding the mtenslty of land use inthe long term and two alternative assumptions were used in the calcu-latlons. Alternative A was based on the assumption that all tenantswould continue to operate at their present intensity of t”ns per acre.This gave very large requirements, as shown in table A.3. AlternativeB assumed that with the advance of technology the land utilizationwould intensify and a figure of 30 per cent higher intensity was used.The reduced requirements given by this alternative assumption arealso shown in table A.3 and m fact tlm was the assumption adoptedfor the master plan

TA B L E A . 1Total cargo commodity flow projections, 1980-2000

(In t h o u s a n d s of shor t - i ons )

General cargoSpecial general cargo:

Lumber 3 5 5Automobiles 2 3 5Iron and steel ., ., 4 1 0Bananas 1 0 2

3 0 16 5 8

4 8 3 4 8 34 2 1 5 3 87 9 5 9 6 01 2 4 150

1 544 1 823

4 848 7 3151 025 1 384

Special general cargo subtotal 1 102

Containers 3 224Break-bulk cargo 1 025

G e n e r a l c a r g o t o t a l 5 351

Liquid bulk cargo*Crude petroleum 7 528Other liquid bulk cargoes 9 040

Liquid bulk cargo total 16 568

2 131

9 3631 747

7 417 10 522 13 231

26 974 47 402 68 8289 040 9 222 9 408

36 014 56 624 78 236

D r y b u l k c a r g o 2 397 2 397 3 009 3 814

Total 2 4 3 1 6 45 828 70 155 95 2x1

16. The forecast was checked against a survey of user “pmion andthe tw” results are shown in flgurc A.4.B. It is interestmg t” note thatport users forecast much lower area requirements than the planningteam and it can be expected that the views of users will often be too

low because of their conventional approach t” long-term planning,which is likely to be less imaginative.

TABLE A.2Intensity of land utilization for cargo handling and storage, 1973

17. The cargo-handling requirements form only part of the landutilizatlon of the port, and similar forecasts of land requxementswere carried “ut for mdustrial, commercial, recreational, mstitu-tional and miscellaneous uses. These are shown in table A.4, wherethe uses are broken down by planning areas--l.c., port zones Againsubstantial increases, parncularly in mdustrial use, are forecast andland has t” be provided for these.

General cargo

C. Master plan decisions

1 8 . As suggested above, the major decision was to carry out sub-stantial dredging, lmked t” the landfill of a new port area of 1,034acres. This landfill is expected t” be carried “ut m co-ordination withthe overall dredgmg programme and the demand for deeper chan-nels. It was also decided that hydrauhc analyses would be requiredand that a hydraulic model would be used. The man alternatwewhich had been discarded in reaching this decision was that of usingoffshore buoys to provide the deep water facilities. This decision wasbased mainly on the fact that the San Pedro Bay area is susceptible toearthquakes and underwater pipelines would be hable to rupture,with serious effects. Moreover, operating experience with single buoymoorings had indicated, in the view of the port planners. a highmaintenance c”st on floating hoses. Expensive dredgmg for plpehnetrench, buoy mamtenance. and ship collision possibilitxs, togetherwith possible ecological effects on marine life, were all contributoryreasons for deciding to prowde deep water insIde the harbour ratherthan utilizing the deep water outside it.

Special general cargo:Lumber ._. 70 3 5 5 5.07Automobiles 197 440 2.23I r o n a n d s t e e l a b b

Bananas 9 1 0 2 1 1 . 3 3__ __ __Special general cargo

s u b t o t a l 2 7 6 897 “.a

Containers 187 3 224 17 24Break-bulk cargo 3 1 4 1 230 3 . 9 1

G e n e r a l c a r g o t o t a l 7 7 7 5 351 n.a.

Liquid bulk cargoDry bulk cargo

2 1 5 16 568 80.4297 2 397 2 4 . 7 1

__ _ _Total 1 089 24 316 “.a.

1 9 . The landfill decision was less difficult since, as shown in figure 2 0 . Once the main lines of development were deaded in this way,A.5, the three possible solutions within the port boundaries were the allocation of land use between the seven different z”nes of thebased on the same area of landfill but with varying quay wall con- port was considered from a fresh pomt of YXW given the combinationfigurations, all of them adopting a major pier approach as described of future possibilities and existing use. In many cases users wereearlier in this chapter (see figure 25 above). The alternatwe selected invited to move t” m”re suitable locations. It was declded t” elimin-had the simplest shape and the broadest piers and connecting arm. ate minor irregularities of quay wall in order t” prowde better berth-

68

mgs. and t” demolish out-of-date superstructures such as warehousesin order t” prowds larger service areas. The resulting land usechange planned far each of the zones IS summarized in table A.5,from which it can be seen that there is no general pohcy of spectabz-mg or of distributing cargoes between zones. Area I, the new landfill,IS allocated a range of cargo types.

2 1 . A commumcatton plan was built up, conststing of a new lay-out for rail connections and road c”nnect~“ns wth a major new roadlink down the cunnecting artn of the proposed south east landfill areaand several slmplihcatlons of trunk access t” other port areas FigureA.6 dlustrates the land use and communtcation network as provtdedfor the 1990 matter plan

2 2 . Before the plan was finaltzed, a renes of Impact analyses werecarried “ut to ensure that the master plan proposed did not createproblems. These consisted of:

[a) An au res”urce impact analysis: this concerned mainly au pol-luting mdustnal actiwties m the port;

(b) A bioioglcal resource unpact analyst thx examined possibleeffects on marme organisms and displacement of fish and plankton;

(c) A geologtcal resource Impact analysis: this conststed of analys-mg the effect on the geologic enwr”nment of the ma]“r channel andlandfill activittes;

(d) A water rcsourcc impact analysis: thts studled water supplyproblems and waste water treatment questtons together wtth naviga-tional safety;

(e) A cultural resource impact analysts: this was a check onarchaeological and historic sttcs;

m A socioeconomic analysts: this major study consisted of rc-viewtng energy requirements, questions of health and safety, employ-ment and aesthettc questions, in close co-“perauon with the localplanning authormes.

FIGURE A.3

Tonnage projections for port of Las Angeles

FIGUREA.~

Comparison of commodity flow projections and land acreage needs

A. Cargo commodtty flow projections

69

B. Land acreage needs

- .-

TABLE A.3

Projected land needs, 1980-2000(In acres)

Commadiiy groq

General cargoSpecial general cargo:

Lumber _.Automobiles ._.Iron and steel’Bananas

Al,wnol‘“s A Alrw”oti”e B

1973 ,980 1996 mm 1980 mm mm

70 9 5 9 5 9 5 7 3 7 3 7 31 9 7 2 8 2 3 6 6 455 216 282 350

79 9 11 1 3 8 1 0- - - -

Special general cargo subtotal 276 3 8 6 4 7 2 5 6 3 296 3 6 3 4 3 3

Containers 1 8 7 2 8 1 4 2 4 5 4 3 216 3 2 6 4 1 8Break-bulk cargo 314 3 4 6 4 5 5 567 266 3 5 0 4 3 6

General cargo total 777 1 013 1 351 1 673 778 1 039 1 287

Liquid bulk car& ,,,.,....,..,............. 2 1 5 4 4 8 7 0 4 9 7 3 3 4 4 542 7 8 4Dry bulk cargo 97 9 7 1 2 2 1 5 4 7 5 94 1 1 8

- __

Total 1 089 1 558 2 177 2 800 1 197 1 675 2 153

* Iron and steel land needs are *“duded I” acreages for a”mnobile and break-bulk facilities b Excluding land rcquirementr ewmared for LNG

FIGURE A.5Alternative landfill prap0SZilS(Alrernatwe C was selected)

TABLE A.4

Summary of land utilization for purposes other than cargo handling and storage, by planning area, 1973(In acres)

ur< I 2 3 4 5 6 8 Porrb

Industrial .,............_........,.,.,........... 5 14 78 1: 6: 221 4 403Commercial _. 1 42 18 5 0 66R e c r e a t i o n a l 70 2 0 0 19 4 9 5I n s t i t u t i o n a l 3 7 0 0 0 23 285

i3 4 5

Other’ ., 22 6 0 5 1 85 374 285 270 1 147- - - -

Total 1 3 5 1 1 8 1 4 7 98 484 800 274 2 056

Porl of Los Angeles, master plan 1990

-

/:i

-.

TABLE A.5

Planned changes in areas for handling ditkent types of cargo(ln acres)

Contarners1 9 7 51 9 9 0

Break-bulk cargo1 9 7 51 9 9 0

Special cargo1 9 7 51 9 9 0

Dry bulk cargo1 9 7 51 9 9 0

Liquid bulk cargo”1 9 7 51 9 9 0

- - 5 7 3 3 1 1 8 6 -6 3 1 7 5 1 5 5 1 0 0 -

1 4 3 3 1 9 5 4 2 3 0- 1 1 - - 250 5 2 1 0 0

-- - 8 9 5 7 1 0 0 - 3 01 3 6 6 0 65 3 0

- 2 1 6 7 01 0 7 0 1 0 0 -

- - 5- - - - 5 - -

72

Chapter VI

NAUTICAL ASPECTS OF PORT PLANNING

A. General considerations

335. In the development of a port. nautical aspectsplay an important role: the movement of vessels in theapproach and access areas. manoeuvring within theport area as well as mooring operations at the termin-als. Site selection for developments should be based onthe most economic and safe location. The purpose ofthis chapter is to promote the systematic planning,realization and implementation of provisions for a safeand expeditious navigation to. in and from these ports.The chapter will be chiefly oriented towards the recep-tion of large ships, because these have a dominatinginfluence on the form and dimensions of a port’s infras-tructure.

336. For deep-water ports that have to be suitablefor the reception of large ships. the problem arises thatthe actual sailed track of these ships-as compared tothe ideal track-may deviate considerably from thoseof conventional vessels (as a result of the long reactiontimes of large ships like VLCCs to. for example, ruddermotions or r.p.m. changes). Such different manoeuvr-ing characteristics can lead to new operational criteriafor traffic in a port’s approaches and other navigationareas. Furthermore. the provisions to be made for safenavigation to and from the ports may be extensive ascompared to those for conventional vessels.

337. Important developments in sea transport arenot necessarily restricted to past decades, but are con-tinually stimulated by technological improvements andchanges in transport demand. If a port and its facilitiesare not adapted to or do not keep track with thesedevelopments, delays, congestion, accidents and col-lisions will result, in short. in inadequate functioning.The penalty for the regional and national economy isalways heavy.

338. Adapting an existing port to new requirementsis often a difficult, time-consuming and expensiveaffair, if originally insufficient flexibility was incorpor-ated in the design. Therefore in the development ofnew ports, first of all. a thorough evaluation should bemade of the type, size and number of vessels that willmake use of the port initially and in the future. andwhether these vessels will arrive and depart loaded orunloaded. Secondlv. because of the mherent inad-equacies and errors’in these evaluations and forecasts.a maximum degree of future adaptability of the port’sapproaches and manoeuvring areas to new types ofships must be built in. A survey of the approach charac-teristics will evaluate local traffic movements. effects ofweather and time, fishing operations and possible chan-nel characteristics.

339. The transition of a ship sailmg in open sea to

the mooring at a terminal can generally be divided intothree phases. This division reflects the type of man-oeuvres to be performed, dependent on the configura-tion of the specific local coastal area. The frrst phase isthe preparatton for the transit movement, the secondphase the negotiating of the port approaches Itself. thefinal slowing down and stopping manoeuvre and thethird phase the approach and mooring to the berth.Similar phases apply to vessels leaving a port, but inreverse. The nature of these transit phases is deter-mined by representative maximum and mimmum sail-ing speeds within which these manoeuvres can be per-formed without breaching acceptable safety criteria.For example. there are maximum and minnnum portentrance velocities within which a ship can still stopinside the port boundaries without taking resort tocrash stop procedures.

340. The above leads to requirements for the hori-zontal and vertical dimensions of the port‘s access andmanoeuvring areas. Manoeuvring characteristics ofvessels with a big mass inertia lead to large manoeuvr-ing space requirements as compared to conventionalvessels. The assistance of tugboats is required at slamsailing speeds and in confined waterways: usually theefficacy of tugboat effort increases with decreasing ves-sel speed. The possibility of failures m the steeringmachine or the propulsion unit of vessels during porttransits cannot be neglected. These deficiencies alreadyoccur more frequently in port transits than in open seabecause of the sudden changes in the regime of theengines. The potential effect of such deficiences shouldbe minimized as much as possible, particularly wheredangerous cargoes are concerned, by adequate portplanning. Deviation from the ideal track in port transitscan be caused by many factors. one of them being thehuman element. Navigators are human beings. and notwo react in the same way to a given instruction. Thedimensioning of the port transit areas should make al-lowance for the variations in these human reactions.

341. In a general sense, the tracks actually saileddepend on the manoeuvring characteristics of the shipconcerned and on the condition of the waters in whichit sails. These in their turn affect the actions taken onthe bridge necessary to guide the vessels through thesubsequent manoeuvres of the port transit. The controlactivities on the bridge are dominated by three dif-ferent types of human actions:

(n) maintaining the required course;

(h) countering at an early stage deviations from theintended track; and

(c) avoiding unstable vessel motions which might re-sult in loss of control in steering the vessel.

73

Unstable vessel motions are associated with resonanceconditions, which vary according to different types andsizes of vessels. Some forms of resonance can be mas-tered by human navigators, while others can only bemastered insufficiently, or not at all. Therefore, in theplanning of port approaches, the investigation into theresponse of design vessels to conditions representativeof the coastal area concerned is very important. Thepurpose should always be to ensure safe navigation toand from the port.

342. Availability of information to the ship’s navi-gators is obviously an essential element: for example,information on the ship’s position with respect to thetrack to be sailed; information of a co-ordinative naturein the context of traffic surveillance and/or guidance inthe port’s navigation areas; and data on environmentalconditions (wind, visibility, waves, currents, tides). Thedesired and feasible degree of integration of these in-formation systems, the required range, accuracy andreliability, and the peak density of the traffic as well aslocal atmospheric conditions jointly determine thetypes and positioning of the equipment to be procured.

343. New research methods permit the systematicinvestigation of the dynamics of port transits andmarine traffic flows. Such investigations provide basicdata, inter alia, for establishing procedures for naviga-tors during port transits. Together with the introduc-tion of advanced electronic navigation systems, theymake it possible to allow the safe and efficient naviga-tion of large and vulnerable vessels to and from a port.

B. Ship manoeuvrability

344. Since the late sixties, considerable researchand development work has been carried out throughoutthe world to define the factors and the relationshipswhich determine a ship’s manoeuvrability and its re-sponse to its own control systems under actual condi-tions in both open and restricted waters. The advent ofthe larger tankers and bulk carriers has provided theincentive for such development, the results of which arebeing applied in the design of ship hulls and ship con-trol systems, in training, in setting navigational require-ments and operational limitations, and in the design ofchannels and other waterways.

345. Considering the factors which influence aship’s manoeuvring behaviour, the basic properties be-longing to the vessel itself are called here vessel man-oeuvring characteristics. They are determined by theship’s hull, its mass, the rudder system and dimensions,the propulsion system and the power. These character-istics are:

(a) The way the ship reacts on the rudder and onchanges in propeller t-evolutions;

(b) Turning ability;

(c) Stopping distance.

346. The L/B (length/beam) ratio and the blockcoefficient, together with the B/d (beam/draft) ratioand the rudder area, mainly determine the manoeuvr-ing characteristics. A small B/d ratio and a large blockcoefficient result in a relatively long time to react to anapplied rudder angle; but once the ship is rotating, it

has a good turning ability. It is clear that these charac-teristics are important for the manoeuvring ability of atanker in a channel. However, equally essential is theway the human operator on the bridge uses these man-oeuvring characteristics in steering the vessel.

347. In confined water, the time to reach ship’s re-sponse to an applied rudder angle can be favourablyinfluenced by a simultaneous rudder and propeller ac-tion, the latter only during a short time to avoid anincrease in ship speed. The effect of this manoeuvreincreases at decreasing speed. In general, course stabil-ity indicates the extent to which the ship reacts to exter-nal disturbances. In shallow water, the course stabilitytends to be better than in deep water.

348. The turning diameter in deep water at servicespeed and a rudder angle of 35” varies considerablybetween types of ships, and even between individualships of the same category. Many container ships havea poor manoeuvring capability, particularly those builtOT originally built to operate at high service speeds of 26or 27 knots. For these ships, turning diameters are inthe order of 6 to 8 ship lengths (L). Turning diametersfor large oil and dry bulk carriers at service speeds inthe range 15-17 knots are in the order of 3 to 4 L, someeven less than 3 L. LNG carriers are mostly in the 2-2.5L range, which would also apply to a great number ofconventional general cargo and multi-purpose vessels.

349. Turning capability at low speeds is often im-proved by the use of a twin propeller arrangement orbow thrusters, or a combination of the two. These mea-sures, however, do not constitute a universal remedyagainst inadequate manoeuvring capability. Many con-tainer ships, for instance, are equipped with twin prop-ellers. However, due to the shape of the hull, the dis-tance between the propellers is so small compared tothe length of the vessel that the turning momentum thatcan be exerted is virtually ineffective. Bow thrusters areuseful for berthing and unberthing operations but, par-ticularly at speeds of 4 to 5 knots, they lose much oftheir effect.

350. The stopping distance of vessels is obviouslystrongly influenced by the relation of astern power ver-sus mass of the vessel. Also, the astern power as afraction of the installed power varies from one systemto another and may be as low as 50 per cent for a vesselwith a steam turbine and fixed blade propeller, or closeto 100 per cent for a vessel with diesel engine and con-trollable pitch propeller. As a result, the distance, S,travelled during a crash stop varies considerably, evenwhen expressed as a function of the vessel’s length, L.For deep water conditions and starting from servicespeed, approximate figures are as follows: large tankersand dry bulk carriers (over, say, 200,000 dwt): S =15-20 L; container ships: 6-8 L; large LNG carriers:1@12 L: conventional general cargo ships and multi-purpose ships: 4-7 L.

351. A vessel making a crash stop has little OT nocourse control due to the flow pattern near the rudderand will generally deviate dramatically from the desiredstraight track. The actual track sailed is highly unpre-dictable. A degree of course control can be maintainedby giving periodically brief ahead propeller thrusts withthe rudder set to give the desired course correction.

74

This however. unavoidably leads to greater stoppingdistances.

C. Effects of environmental conditions

352. The manoeuvring characteristics and man-oeuvring behaviour of ships are strongly influenced byenvironmental conditions, particularly by:

(a) Shallow water effects: increased resistance,squat, bank effects. changed response on rudder;

(0) Waves and swell: stable or unstable course de-viations, increased resistance. sometimes reduced rud-der response;

(c) Currents and winds: drift motions.

Cross-current or cross-wind components induce a side-ways drift to vessels. To maintain course. a vessel willhave to steer at an angle with its theoretical course. Asthere are practical limitations to this drift angle. thephenomenon becomes of particular importance in porttransit manoeuvres, the more so, because the effect ofcross currents increases with decreasing keel clearance.Waves and swell have a considerable effect on coursestability and on the required allowances for deviationsfrom the ideal track when navigating in constrainedwaterways. The effects however, cannot be general-ized, but must be investigated for every situation; theywill not be further discussed here. The consequences ofship’s response to waves and swell for the design depthof dredged channels are mentioned in paragraphs 359and 360 below.

353. The influence of water depth on a ship in mo-tion becomes noticeable at a depth of less than about 4times the ship’s draught. The influence becomes signifi-cant at a depth of approximately 1.5 times the ship’sdraught. Shallow waters are therefore usually definedas fairways with a depth of 1.5 times a ship’s draught orless.

354. An important shallow water effect is the in-crease of the squat of a vessel, that is, the sinkageresulting from the return currents along the sides andunder the keel. Many investigations have been carriedout into this phenomenon and many formulae de-veloped. The squat is essentially proportional to thesquare of the ship’s speed.

355. The effects of shallow water on the manoeuvr-ing characteristics are an increased course stabilityagainst a decreased rudder efficiency. In other words,there will be a decreased tendency of a vessel to zigzagaround its ideal track. On the other hand. turning radiiwill increase and the response to rudder angles will beslower. Due to increased resistance of the water. stop-ping distances will relatively decrease in shallow water,although not in a spectacular way.

356. A special aspect of the shallow water effects isthe sailing above or through low-density mud (slingmud). For a number of ports. these aspects have directconsequences for their channel maintenance pohcy oraccessibihty criteria (Rotterdam, Shanghai. Bangkok,Paramaribo, Cayenne). In general, it can be statedthat, because of the higher rudder efficiency due to thehigher propeller speed in navigation under silt condi-

tions. dynamic movements such as changes in coursewill be initiated more directly, while less time and spacewill be necessary for their execution on account of thedamping action of the silt.

357. Attention is drawn to the work of the IMOSub-Committee on Ship Design and Equipment. whichhas been considering manoeuvrability characteristics,squat and hydrodynamic forces in shallow water, andwhich can supply much relevant information.

D. Consequences for port planning

358. In this section, the consequences for port plan-ning are given in an indicative way and to the extentthat they can be more or less generalized. It should beappreciated that no two ports are alike and that nostandard solutions can be given.

1. DEPTH OF APPROACH CHANNELS

359. The required keel clearance and safety mar-gins are schematically shown in figure 27.

FIGLRE 27

Definition of under-keel clearances

This figure is a simplification of the actual conditions.The vertical movement of a ship in response to wavesand swell is in fact a stochastic parameter. for which theprobability of exceeding a given value can be deter-mined, if the local wave conditions as well as the ship’sresponse characteristics are known in sufficient detail.These response characteristics in their turn may varysignificantly between vessels of the same size and class.Furthermore, the actual channel bottom level, as a re-sult of dredging inaccuracies and sedimentation, is nota flat plane. nor are there fixed tolerances to determinea nominal level. Lack of detailed information results ina certain degree of simplification, and estimation isusually applied.

360. PIANC suggests. by way of approximation,that the gross under-keel clearance can be taken asfollows:

(a) Open sea areas exposed to strong and long stern

75

- -

or quarter swell, high vessel speed: 20 per cent of themaximum draught;

(b) Channel and waiting areas exposed to strong andlong swell: 15 per cent of the draught;

(c) Channel less exposed: 10 per cent.Obviously these percentages may vary appreciablyfrom one location to another, depending on physicalconditions. Moreover, it is emphasized that the figuresapply strictly to large ships, which for this purpose aredefined by PIANC as vessels of 200,000 dwt or over.For conventional vessels, or even for LNG carriers,these percentages would in many instances be grosslyinsufficient.

361. It is emphasized that for channels subject totidal motion, not all ships need be able to enter or leaveport at all stages of the tide. On the contrary, it willoften be more economic to restrict the navigability ofthe channel, at least for the biggest ships. to a limitedperiod of the tide. The type and number of ships in-volved and the applicable degree of restriction-i.e. thewidth of the “tidal window”-must be studied fromcase to case. It will normally be determined on the basisof a minimization of the sum of channel constructionand maintenance cost, and of the ship waiting cost. Inpractice, there are often considerable hidden waitingcosts, because ships tend to reduce speed well in ad-vance of the harbour entry rather than have to wait atan anchorage.

2. CHANNELWIDTH

362. A ship will generally not be able to navigate achannel in a position parallel to the channel axis orleading line. The forces acting on the ship by crosscurrents and wind necessitate steering under an angle-the drift angle-in order to follow this leading line. Inthis way a state of equilibrium is reached between ex-ternal momentum and forces, and those from resistanceand rudder. It is possible to determine this drift anglefor varying circumstances by means of model tests. Inconfined water it turns out that under the above-mentioned external conditions, the ship also needs acompensating rudder angle to keep the ship on averageon a straight track. Especially for channel-axis naviga-tion in cross currents, relatively large rudder angles areneeded for course correction to preclude a further drift-ing away from the straight track. The drift angle hasconsequences for the path-width used by the vessel,which at 10” is already approximately twice the beam.The limitation of the drift angle may have conse-quences for the minimum sailing speed in the channel.

363. The channel width required for a one-waychannel consists of the path-width, the compensatingwidth for the motions which a ship makes around thetheoretical straight line course, the compensating widthfor location information inaccuracy, and a safety mar-gin. The translation of the above into actual dimensionsis not a straightforward matter. Methods used for thispurpose are as follows:

(a) The empiric method: making use of experiencewith other channels elsewhere and converting qualita-tive opinions of navigators into quantitative terms;

(6) Physical model investigations;(c) The maximum deviation method: quantifying the

effect of correct and specified pilot response on vesselswith specified manoeuvring characteristics after a cer-tain minimum deviation from the ideal course hasoccurred;

(d) Mathematical navigation simulation models in-corporating computerized pilot reactions on compu-terized ship’s performance;

(e) Real-time navigation simulation, using a simula-tor comparable to the link trainers in aviation trainingof pilots or navigators.Methods (d) and (e) belong to the sphere of probabilis-tic research and design methods and, when used incombination, may be expected to give the most con-vincing results. Their reliability will increase with theimprovement of modelling vessel response to the com-plex external forces in restraint waterways.

364. Research and experience so far have shownthat the required channel width depends particularly onenvironmental conditions such as cross currents andcross-current gradients (variation of these cross cur-rents per unit length of channel), waves and swell, windand visibility, as well as on the accuracy of informationregarding the ship’s position and the easy “readability”of this information by navigators. A minimum value forthe width of a one-way channel (width at full depth)would be 5 times the beam width (9) of the biggestvessel in the absence of cross currents, while an averagevalue for average conditions is more likely to be 7-8 9.Actual one-way channel width in existing ports variesbetween 4 and 10 B.

365. For two-way traffic, a distinction must bemade between vessel types for which encounters areallowed. If two-way traffic is required for the biggestvessels, channel width should be increased relative tothe one-way channel by 3-5 B plus compensation for adrift angle. In curves, ample and gradual wideningshould be provided for. The magnitude of this wideningis again strongly influenced, apart from the radius ofthe curve, by currents and, particularly, currentchanges.

3. CHANNELLAYOUT

366. The layout of an approach channel is oftenlargely dictated by the local sea-bed topography andother local conditions. In so far as alternative layoutsare possible, the following aspects should be duly con-sidered in their evaluation:

(a) A channel should show as little curvature as pos-sible. Curves should in particular be avoided near theharbour entrance, as this is nautically already a difficultpoint;

(6) A single curve is better than a sequence of smal-ler curves; distance between curves should be at least10 L;

(c) Curve radius should be greater than or equal to10 L, or in exceptional cases 5 L;

(d) Cross currents should as much as possible be

7 6

avoided. This applies even more to high cross-currentgradients. for instance near the harbour entrance and incurves;

(e) Anchorages (normal or emergency) should beprovided along the length of the channel. of which thelast one should be located close to the port entrance.

367. The manoeuvring of small to medium-sizedvessels generally poses no special problem in the sensethat specific measures have to be taken in the dimen-sioning of the port infrastructure. The required stop-ping lengths are limited and can generally be accommo-dated in traditionally sized inner channels and man-oeuvring spaces, Manoeuvring capability of these ves-sels is generally good, and upon entering port they willoften manoeuvre and stop under their own power.

368. For large ships the situation is different. Be-cause of their much longer stopping distance and theirlack of course control during the stopping manoeuvre,they will generally not be allowed to stop under theirown power. This may already apply to vessels ofapproximately 50,000 dwt and over. This means thatsuch ships, as long as no effective tugboat control isavailable, have to maintain a certain minimum speedrelative to the water at which there is still sufficientrudder control available. This speed is about 3-4 knots,sometimes slightly less. The above is of particular im-portance where large ships with dangerous cargoes areconcerned, for example, crude and product tankers,liquid gas carriers, etc.

369. The slowing down and stopping length thenrequired within the port boundaries, that is. in rela-tively sheltered water with little or no currents, is deter-mined by the entrance speed of large ships. the time

required to tie up the tugboats and to manoeuvre theminto position: and the actual stopping length.

370. Consequently, the length ot the inner chan-nel-in terms of aviation, the runway of the port-should generally measure 3-4 km and more, to allowthe port to be able to receive large ships under accept-able standards of nautical safety. The slowing-downand stopping length can be decreased to the extent thatthe ship’s entrance speed can be reduced. The lattercan be attained by limiting port entrance for large ves-sels to a certain maximum cross current. Although thishas operational consequences. it may nevertheless beeconomically attractive The concept of introducingplanned port transit navigation for large and very largeships (i.e. making entry and departure subject to. infer&a, vertical and horizontal tide. as well as sea condi-tions) will in many Instances be a sound one.

371. Immediately past the port entrance. the navig-able width of the channel should be increased. This isnecessary as the drift angle of vessels upon entering hasan initial tendency to increase: the bow of the vessel isin more or less current-free water. while the stern stillexperiences the cross currents. The width can graduallybe brought back to around 7 B. The boundaries of thechannel should preferably consist of flat slopes andshould be free of obstacles. Under no circumstancesshould oil, chemical or gas tankers or ships be mooredimmediately adjacent to main manoeuvring areas.

372. The inner channel should end in a turningbasin or circle. from where vessels, whether small orbig, are towed by tugboats to their respective basins.The diameter of this turning basin should be equal to orgreater than 2 L of the largest ships. In exceptionalcases for small ports where no tugboats are available;the diameter should be equal to or greater than 3 L. Incase of currents. for instance in river ports. the turningbasin should be lengthened to compensate for vesseldrift during manoeuvring.

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Chapter VII

CIVIL ENGINEERING ASPECTS

A. Introduction

373. The objective of this chapter is, on the onehand, to outline the role of the civil engineer in portdevelopment and, on the other, to summarise the mainsteps and techniques used. The text is also intended tobe readable for someone with a non-engineering back-ground. Engineering cost estimates and subsequent in-vestment decisions must be based on detailed studies byexperienced civil engineers.

374. The work of engineers in a port developmentproject extends over a long period. Starting with initialstudies of the development potential of alternativesites, the costs of engineering proposals which meet thewater and land area needs are broadly estimated to givethe basis for the investment appraisal and the projectdecision. Detailed drawings and specifications are thenprepared; contracts are awarded; the construction workis supervised, and, finally, the new facilities are handedover to the operating authority.

375. In this chapter, attention is directed to the partplayed by the engineer in the studies leading to an in-vestment programme. Technical judgement is import-ant to enable proper estimates of development alterna-tives to be prepared, but close attention to detail is notnecessary at this stage.

376. A most important feature of the engineers’work in the project team is that estimates should berealistic. The starting points for this are a sound know-ledge of the physical features of the site and a fullappreciation of the requirements of the various types ofshipping and port traffic.

B. Field investigations

1. GENERAL

377. Careful investigation of the site is essential tothe success of the project. Field investigation means thestudy of all physical features of the area:

(a) Hydrography and topography;(b) Meteorological and oceanographic influences;(c) Coastal hydraulics, which comprise the local in-

fluence of the sea on the shoreline processes;(d) Exploration of the subsoils both on land and

under the sea.Field studies may be supplemented by the use of specialhydraulic modelling techniques to forecast changes dueto port construction works. A list of the site investiga-tions which may be required, together with their char-acteristics, is given in table 12.

2. HYDROGRAPHICANDTOPOGRAPHICSURVEYS

378. Reliable information on the bathymetry (thedepths of water in the sea or river) is essential. Thedepths of water are represented on charts by figures forindividual soundings or by submarine contours.

379. For a new project, the hydrographic chartsavailable may provide sufficient information for pre-liminary engineering purposes. It may also be possibleto obtain copies of the working charts of the hydro-graphic surveyors who did the original work for thehydrographic charts, and these may show soundings atcloser intervals than those given on the publishedcharts.

380. However, hydrographic charts are often out ofdate or not available and a detailed bathymetric surveymust be planned. When the area to be sounded is large,and shore points are insufficient to permit a good loca-tion of sounding points, it can be of interest to put intooperation-during the whole of the surveying period-one of the radio location systems that are on the mar-ket. Such a system requires specialists to assure itsmaintenance. The area selected for the survey shouldbe large enough to allow for alternative sea approachesand alternative locations for the port installations.

381. Most bathymetric surveys are now carried outby means of a high-resolution echo sounder, which canbe mounted in a suitable vessel obtained locally. Theolder method of taking soundings by lead line is stillused, however, particularly in awkward places and nearstructures.

382. Some topographical surveying is required inconjunction with hydrographic surveying to establishshore points. In addition, a survey of the land areasassociated with the port works is required.

383. For a new port site, after a first examination ofall available plans, an area should be defined for anoutline survey, and permanent survey points estab-lished. As the project crystallizes, the extent of surveywork required is more closely defined and the degree ofdetail correspondingly increased.

384. For the production of contract drawings, fullydetailed survey plans of the port area, with particularattention to road and rail access, should be prepared. Asuitable scale for these plans would be l:l,OOO.

3. METEOROLOGICALSURVEY

385. Most inhabited regions of the world haveweather records, although in some cases they may beinsufficient for statistical trends to be fully assessed.

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TABLE 12List of site investigations

Bathymetrtc survey “t Water depthside-scan sonar survey ProfIle. obstacles. wrecks, ctc

Topographtc survey Co<~rtal topography

Meteorofogtcal survey Donnnant winds (speed. dtrect~on. dureLl”” “I gusts)

Frequency and aevertty of ~tomtsVtsibihtyRainfall

Oceanographic and hyd-rauhc surveys

WC! \‘aOftshore wave stattsttcsLocal waye patterns

SW-m surgeAmplitudeFrrquency

curremCoastal and estnartne currents (mtensity,

direction, variations)Tidal cwrents

TidesMean water levelTtdal fluctuation (range. stattsttcs)

SedmeniaironLtttoral drift regnneZ o n e s o f stabtlity. eroston a n d

sedtmentationRiver siltanon

Geotechnical surve,(subsoil investig&on)

GeologySeisnnc sounding of subsotl strata

Subsoil expioranonldentiftcatton of soilEngmeermg properties of rock, etcPenetrabihty and sheartng strength of

soft soils

Analysis of water ptop- Phwcal chemsrry of the walerenies Salimtv

Pollutt”nTurbtdity (muddiness)

Envtronmental impact study Marine fauna and floraExtstmg and future uses of land

Chotce of X;I approachLocation of port mstallatton\Type of PortEase of landward AccessExtent of land areas availableOrtentetton of approach channel, har-

bour enttancr snd berthsBreakwater destgnShop manoeuvrmg requiremrntsLost capactty dus to mrerruprrd workmgNavtgnbonal alds

Breekwarer designProfile of channel and harbour bedProfile of banks, beaches and qnay wallsonenrat1on of channela. p*ers. etc.Mamtznancs drrdgmg need\Quay wall designRrquirementa lor locks and basinsShtp manoeuvring requnements

Design of port strnctntesDesign and costmg of dredgmg and recla-

matlo” programmes

C”rr”sl”” of stt”CtntesCompletes the data for sedimentatton in-

vestigatmnsProvides data for environmental nnpact

study

Effect of port works on dtfferenr spe-cies

Interference with hshingImpact of works on: sgnculture;

urban development; letsure activt-ties; historic sttes and monuments

Nevertheless, it may be reasonably expected that, for 4 . O C E A N O G R A P H I C S U R V E Y

any port site, wind and rainfall records will be availablefrom some adjacent location, which will serve at least 387. Oceanography is the study of the behaviour offor a preliminary study. Once the si te has been the sea, and covers a wide range of natural phenomena.selected, an anemometer, a rain gauge and a barograph For a port project, the particular factors of concern areshould be set up to record the weather throughout the waves: currents and tides.construction stage and eventually to become part of the 388.operational activity of the port.

The length, height and period of waves arriv-ing offshore may be estimated from wind records.

386. Knowledge of the frequency and severity of Waves depend on the wind’s speed, duration and fetchstorms is important in designing maritime engineering (the distance over which the wind has acted on theworks. With the continuously recording anemometer, water), and empirical relationships exist between thesewind speeds and directions and duration of gusts will be factors and the waves generated. Records of ships giveobtained. further wave information, but direct measurement of

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waves is the most reliable method. This is usually doneby means of a wave recorder.

389. The major ocean currents are well known, butthey are of much less significance for the designing of anew port than the local currents, which should be mea-sured.

390. Tide records are usually fairly reliable, butcare is often needed to ensure the correct datum oftides related to land survey and soundings. A datumcan be obtained by recording the tide over a period ofat least one month and establishing the mean waterlevel. Tide gauges can then be fixed in relation to thisdatum and tide readings continued during the projectperiod.

5. COASTAL HYDRAULIC SURVEY

(a) Waves

391. It is preferable to measure the waves occurringat the port site directly. Many types of wave recordersare suitable and in the selection of an appropriate type,the most important factor is its suitability for local oper-ation and maintenance. The statistical extrapolation ofrecords taken over a period of time permits computa-tion of the likely frequency of recurrence of a givenheight of wave, or alternatively, of the wave heightsassociated with storms of a certain frequency of recurr-ence (such as once a year, or once every 10. 50 or 100years).

392. The interaction of the wave with the sea-bedas the wave travels towards the shore modifies thedirection and height of the wave. The effects of shoal-ing and refraction are complex, but simplifiedapproaches and computation are usually adopted forport planning purposes. Further details are available inthe reports of the PIANC Commission on the Study ofWaves.

(b) Currents

393. Currents must be studied in the vicinity of theport in order to establish their speed and directions atthe various stages of the tidal range. Seasonal and lunarvariations in the currents and the effects of fresh waterflow, in the case of an estuary, must also be taken intoaccount.

394. Coastal currents are measured by the use offloats, which are released at predetermined positionsand their subsequent tracks plotted, or by use of cur-rent meters which record the variations of strength anddirection at a fixed point.

(c) Littoral drift

395. When there is a current close to the coast, thecombination of wave action on the shore, which loosensmaterial, and the current, which transports beach ma-terial, can alter the coastline. This mechanism of sedi-ment transport is called littoral drift. Over a period,littoral drift may occur in one direction and then in thereverse direction, but generally there will be one direc-tion which predominates.

396. Where the beach is interrupted by a featuresuch as a tidal inlet or an estuary, a spit tends to form inthe direction of the predominant movement of ma-terial. Similarly, if an obstruction such as a breakwateris placed across the beach, material will build up on oneside of the obstruction and erosion will occur on theother side. (Figure 28 illustrates the effect of littoraldrift in a constant direction). It is therefore importantin planning a coastal harbour to estimate the amount oflittoral drift and to investigate its likely effects.

397. When no simpler means of estimating littoraldrift are available, tracers can be used. This methodinvolves tracing the course of materials that have beenmarked and laid down on the sea-bed or on beaches,and which in addition to visual tracking can be tracedby luminescence or radioactivity. Such surveys are nor-mally carried out by specialized hydraulic laboratories.

6. GEOTECHNICAL SURVEY

398. Geotechnical site investigation is an importantpreliminary to maritime construction. Exploratoryoffshore drilling either from floating craft or from atemporary platform is expensive, but the cost of theinvestigation is normally small relative to the value ofthe works constructed.

399. The following are the main methods used forinvestigating the subsoil:

(a) Boreholes formed by excavating within a liningtube. Also termed shell and auger drilling, this method

Direction oflittoral drift

FI G U R E 28

Effect of littoral drift 0x1 coastal harbour

Or ig ina l shore l ine

uses a cvlindrical cutter, with chisels for rock or otherobstructions. Operation is by a wire rope connected toa winch. Undisturbed core samples are obtained forclose examination.

(b) Bol-r/&es formed by rotary drillmg. A hardeneddrill is used to recover cores of rock. This method isslow and costly. and therefore used only when the pre-cise engineering properties of the hard strata need to hedetermined for the purposes of the foundations ot en-gineering works.

(c) Pertc~onre~rr resis. To investigate soft subsoils. acone is forced down into the soil by steady pressure.The side friction and end resistance give the reqmreddata. It is usual to supplement the penetration test byconventional shell and auger boreholes

(d) Wash i>rohes. Certain limited information aboutthe general nature of certain soil strata may be achtevedby use of a high-pressure water jet probe.

(e) Vane rcsr~. For shearing strength measurementsof subsoils, it is important to avoid structural disturb-ance of the samples. Thus, a borehole is sunk to therequired depth. a four-bladed vane is inserted into theundisturbed subsoil at the bottom of the borehole androtated until the subsoil has failed. providing a measureof its strength.

If) Geopitysical e~$orarion. Seismic soundings pro-vide information on the boundaries between differentsubsoil strata. They must be supplemented by one ormore of the direct exploratory methods describedabove.

400. The exact form of the geotechnical investiga-tion will be different for each site and project. Interna-tional standards agreed upon for the classification ofsoils should be used. The aim should be to improveknowledge of the quality of soils as the project de-velops. but since in many parts of the world the costs ofthe mobilization of personnel and equipment (particu-larly for offshore boreholes) are high, full value mustbe obtained from any programme of work: returninglater to gather supplementary information can be veryexpensive.

I. HYDRAULICMODELSTUDIES

401. The techniques of hydraulic modelling, bothphysical and mathematical. are advancing rapidly. Inmany projects the need for model studies will not arise,but in various special situations the use of models isimportant for the prediction of changes due to theproposed development works and for the achievementof economies in construction and maintenance costs.

402. Model investigations for port planning and de-sign are normally undertaken in conjunction with a ma-jor hydraulic research institute, and the engineer wouldnormally discuss the requirements of the project withone of these organtzations before formulating an ap-plied research programme.

403. Three physical features of the port environ-ment are normally studied throug,h models: the move-ment of water and its effect on shtps; the movement ofsoil and its eftect on navigation areas: and the effects of

the marine environment on the stability and safety ofstructures.

404. A physical hydraulic model of a proposed portlayout enables wave action to be measured for variousbreakwater configurations and quay locations, and anoptimum solution selected. The sample models com-pare wave heights by direct measurement, hut moresophisticated techniques are available to study themovement of model ships.

405. In a river or estuarial port. the construction ofnew facilities can alter tidal heights and veloctties.which in turn can affect the movement of bed materialand the siltation and erosion of navigation channels.Mathematical models and physical models are availablefor the prediction of such changes and they provide theengineer with a valuable means of judging the bestform of development. This work is speciahzed. andconsiderable experience is needed; very careful on-the-spot measurements and considerable experimentationare often needed to ensure the most useful results.

406. Coastal movements caused by a new develop-ment may he conveniently studied by means of mathe-matical models, and stmilar techniques can. for exam-ple. determine the alteration in wave action caused bydredging a channel or by depositing dredged materialoffshore. In addttion to the normal three-dimensionalmodels. two-dimensional physical models are fre-quently used in designing breakwaters in order to studythe stability of the construction and the possible erosionof the sea-bed.

407. It is often the case that, although there may beconsiderable scope for model investigation during aproject. the time required to carry out a full model testprogramme is not available during the period of a feasi-bility study, particularly when a lengthy programme inthe field and in the laboratory is needed. In such a caseit may be possible to formulate the initial investmentprogramme in such a way that technically difficult de-cisions are left until iater stages. thus permitting a care-ful investigation during the earlier years of projectimplementation.

C. Water area requirements

1. SHIPDRALIGHTRLJLEOFTHUMB

408. For water depth planning, the curves showingfull-load draught, together with length and beam, fortypical modern ships of each type, given in part two ofthe handbook (chapter VII, figure 35), may be used. Auseful rule of thumb for planners who do not havepermanent access to the curves is as follows:

Full-load draught ,n metres equals

For example. a lOO,OOO-ton hulk carrier draws roughly(m+5) metres, i.e. 15 metres.

409. This formula will give the draught to within 1metre over the range lO,OOf!-500,000 dwt, for dry andliquid hulk carriers. It also gives a valid figure for gen-eral cargo ships down to about 5.000 dwt. For vesselsbelow 5,000 dwt it gives an overestimate of the draught.

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and for second- and third-generation container ships itgives an underestimate of the draught of about 1 metre.

2. APPROACHCHANNELS

(a) Introduction

410. In the immediate approaches to a harbour,shipping is usually obliged to sail within a prescribedapproach channel. This corridor may be purely for thesake of navigational discipline, or it may be necessaryin order to direct ships along a course where there issufficient depth of water. Most major ports, particu-larly as ships increase in size, are likely to beapproached by way of either an artificial channel or anatural channel which may require maintenance dredg-ing. The planner is referred to the previous chapter(“Nautical aspects”), which also discusses approachchannels.

(b) Site investigation data

411. The determination of the feasibility of con-structing an access channel requires a knowledge of thedirection and strength of the currents and the predomi-nant direction of the waves since, under current andwave action, considerable movement of bed materialcan take place. This is most likely to happen where thechannel nears a natural shoreline and the water be-comes shallow, There have been cases of rapid infillingof channels caused by the action of waves and currents.

412. If the harbour is situated in the vicinity of ariver, the amount of suspended sediment in the riverflow must also be studied, preferably for at least oneyear. Insight into likely problems can be gained from astudy of historical records of the site.

(c) Conceptual design of channel

413. The basic aim in approach channel design isthe safe passage of all vessels requiring to call at theport from the sea to the berthing area.

414. If, for reasons of economy, it is decided torestrict the depth of the channel, the depth must never-theless be sufficient to allow vessels with the deepestdraught to pass through the shallowest reach of thechannel at some stage in each tidal cycle. The designmethod includes the construction of time-related dia-grams indicating the interrelation of vessel passagetimes, tide level and water depth.

415. The requirements with regard to speeds of ves-sels in the channel are to some extent conflicting. In along channel the transit time, and hence speed, of adeep-draught vessel may be critical if the vessel is topass through a shallow area at a given time, whereasincreased speed results in increased squat of the vessel,thus reducing its under-keel clearance.

416. The channel dimensions, together with thedepths of water to be provided at berths and moorings,will have a profound effect on the levels of servicewhich the port can offer to the increasing number oflarger ships. Normally, a joint economic and engineer-

ing study must be conducted to determine what policyshould be adopted. In projects where the water areaquestions are important, the calculation of advantagesand disadvantages for the range of options open can bedifficult, but it must be carried out on the basis of thebest information available, and it may be advisable tocarry out a traffic simulation linking the time-and-tide-related vessel passage diagram to the traffic arrivalrates and service times. This can be done by hand, withthe aid of the planning chart given in part two of thehandbook, but that might be laborious, and it would beuseful if a computer-based simulation model could beused for this purpose.

(d) Width of channel

417. A major consideration will be whether thechannel should be wide enough to allow ships to pass inopposite directions. Unless there are severe economicrestraints, a two-way channel should be made in orderto offer unrestricted access to the port. A secondaryconsideration is that if there is an accident in one laneof the channel, access to the port will still be possibleand so there will be less disruption of traffic to and fromthe part.

418. Channel widths depend on the size of ship tobe catered for and the physical conditions of the site.As a typical example, illustrated in figure 29 in a well-marked channel, the total width of full-depth channelrequired for two-lane traffic may be taken to comprise,on straight reaches, manoeuvring lanes of about twicethe vessel beam for each direction, plus about 30metres between vessels and up to one-and-a-half timesthe beam for bank clearance each side. For a typical20,000 dwt cargo vessel, a total width of about 190metres would be appropriate.

419. At bends in the channel, greater widths arerequired than on straight stretches because of the ten-dency of ships to drift on turning. An additional width,depending upon the radius of curvature of the bend butapproximately equal to the beam of each vessel, will berequired in order to allow for the projected width ofvessels negotiating the bend. This feature of projectedwidth will also occur on straight reaches of channelsubject to the action of cross-winds and currents, whichwill also cause vessels to drift.

(e) Depth of channel

420. Consideration of the depth of water to be pro-vided in a channel is complex and inevitably a com-promise has to be reached between, on the one hand,allowing unimpeded access permitting the largest shipexpected to use the channel at all stages of the tide, andon the other hand, excluding large vessels, imposingload-factor limitations on them or giving them accessonly at high tide. The cost of dredging to provide andmaintain a deep channel for an occasional caller can bevery high.

421. Where the nature of the traffic is such that thelargest ships carry full loads in only one direction, i.e.either export or import, a deeper channel can be pro-vided in the appropriate direction if a clear separationis possible.

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FIGURE 29

Typical width dimensions of channel

422. Factors to be considered in deliberations ofthis kind are as follows:

(a) The transit times of vessels along the channel,both with and against the tidal stream. and the relation-ship of these times to the tidal cycle;

(b) The nature of the sea or river bed which, if ofsoft silt. for instance, might lead to a decision to reducethe designed under-keel clearance for vessels using thechannel;

(c) The ship draught: upon entering an approachchannel, the load-line draught of the vessel is modifiedby such factors as water density changes, which mayoccur along the length of the channel, the effect ofsquat and of wave action causing pitch and roll of theship.

423. Each case and location must be studied to fin-alize channel depth design, but a preliminary assess-ment of the order of magnitude is usually possible andsufficient for initial studies. A general cargo ship with adraught of 9 m at sea would squat about 50 cm in anarrow channel; pitching would require about half thewave height in additional draught. and rolling some-what less. Moving into fresh water would add about 25cm to the draught but would usually occur only in shel-tered water, where pitching and rolhng are not present.Thus, allowing 50 cm for bed clearance if the channelbed is soft, it might be assumed, for preliminary plan-ning purposes, that a vessel drawing 9 m might requiresome 10.50 m of dredged depth in an approach chan-nel. A greater depth would be necessary where thechannel bed was hard. At certain ports having depositsof very soft mud, a zero or even a negative under-keelclearance may be acceptable, but such cases requirevery special consideration.

424. It should be appreciated that channels are notalways of uniform depth, especially if they he along animproved natural feature such as a river or tidal inlet.For example, a relatively long channel may be limited

in depth only over a small proportion of its length.Regular dredging of this localized area may provide thedepth required to allow vessels to traverse the entirelength of the channel unrestricted by. considerations oftide and thus greatly facilitate accessibility to the port.

425. A ship that is to travel along an approachchannel should have a draught no greater than thatwhich will allow a specified safe clearance over thechannel bed in the shallowest reaches of the channel.As suggested above, a minimum clearence of l-l.50 mmight be taken as appropriate for most vessels. Thespecified clearance usually allows for squat, so that theactual under-keel clearance will be less than that speci-fied. Where the under-keel clearance of a vessel is ex-pected to be critical, the transit time of the vessel alongthe channel, the time of the vessel’s arrival at the shal-low reaches and the state of the tide at that time mustbe carefully calculated, contingency provisions beingmade for vessels failing to traverse the shallow reach atthe required time.

(f) Channel alignment

426. The manoeuvrability of a vessel moving in aconfined waterway of limited depth is impaired twoways: (a) because the ship takes longer to respond tothe helm, owing to the effects of shallow water: and

(b) because the proximity of the sides of the channeltends to cause the vessel to be drawn towards them.This attraction or suction experienced by the ship to-wards the sides of the channel also applies between twovessels when passing.

427. Where there are changes of direction in thealignment of a channel, these limitations on ships’ man-oeuvrability must therefore be taken into account. Theradii of bends must be as large as is practicable, andrequired ship movements must be kept as sample aspossible.

83

-.. -

428. The desirable geometry of bends in naviga-tional channels for deep-sea general cargo ships may betaken as:

Angle of deflection not more than 30 degrees;Radius of curvature not less than 1,500 metres.429. A channel in the open sea should, if practi-

cable, be aligned with the predominant storm directionand the principal current directions. Where these dif-fer, and where other conflicting constraints arise,model studies are called for. Where a channel is situ-ated within a large estuary or river, model studies willalso be advisable, except in the simplest of cases.

3. LAY-BYSANDTURNlNGAREAS

430. Lay-bys are anchorages or berths where shipsmay be held for quarantine or other inspection, whileawaiting change in weather conditions, or whenqueueing for service at the port. Special anchoragesavailable for ships carrying explosives or dangerous car-go are separately provided and such areas should be sodesignated on charts. The anchorages are usually lo-cated away from the marine terminal and adjacent tomain channels so that they are near deep water, butclear of other ship movement. Allowance must bemade, in allocating lay-by areas, for the distance ofswing out, during the tidal cycle, of a ship at anchor ormoored at a buoy.

431. Lay-by areas may, in common with the har-bour area, be protected either by natural features or byartificial structures such as breakwaters, but at manyports vessels wait for berths by anchoring off-shore.

432. In the immediate approaches to berths, vessels

usually have to make more complicated manoeuvresthan are necessary in the approach channel. Conse-quently, appropriately generous water areas must beprovided and in most cases the assistance of a tug willbe required.

433. The most basic of these manoeuvres is turningthe vessel and it may be taken as a general indication ofthe space required to turn a vessel that a circle with adiameter four times the ship’s length is required wherethere is no assistance from tugs. Where assistance fromtugs is available, a circle half this size is adequate.These are average figures and the actual area neededwill depend, in addition, on wind, wave and currentconditions in any particular case. Shipping lines shouldbe consulted during this stage of the planning.

434. Where space is limited, the ship may be turnedby warping around the end of a pier or a dolphin. Somemodern vessels are equipped with bow thrusters whichconsiderably enhance their manoeuvrability and forsuch vessels restricted sea room is possible. However,for the majority of ports there will still be many vesselsrequiring the larger areas referred to above.

4. TIDALHARBOURSANDLOCKEDBASINS

435. An important decision in the conceptual de-sign of the port is whether berths in the harbour shouldbe open to tidal influences or whether a locked basinmay be justified. A locked basin-sometimes referredto as a wet dock-is one in which an area of water ismaintained at a fixed level, usually equal to the highwater level of the tidal water outside the dock. Accessto the dock is achieved by means of a ship lock. Thisarrangement is illustrated in figure 30.

FKXJRE 30Example of a locked basin

A

t-

S e c t i o n A - A

84

436. Where the tidal range is so wide that an excep-tionally deep harbour, and so high quay walls, would berequired in order to allow ships to remain afloat at lowwater, there would be a strong argument in favour ofhaving a locked entrance to the dock. Tidal fluctuationsmay also cause problems with regard to the loading andunloading of ships at quays. Some vessels, such as bulkcarriers and oil tankers, can more easily accommodatetidal variations while loading and unloading thanothers, such as ro/ro ships. The type of traffic musttherefore be taken into account when considering thepossible need for a locked basin.

437. The disadvantages of the locked basin are:

(a) The high cost involved in providing the sealingdam and the ship lock itself, which is a complicated civilengineering construction, although the larger the num-ber of berths over which the cost of the impoundingdam and ship lock can be spread. the more viable theproposition becomes;

(b) The delays to shipping resulting from the lockingoperation;

(c) The rigid limitation on the maximum size of shipaccommodated.

438. To take a specific example, at a port with asubstantial number of berths and where the tidal rangewas about 3 metres, facilities for larger vessels wereprovided economically by impounding the whole basinat high water level, The cost of the new lock was lessthan it would have cost to deepen the harbour. A cru-cial factor in this case was the fact that it was possible tocontinue using the harbour during construction of thelock. In some cases, costs can be reduced by prefabri-cating a concrete lock in one or several sections awayfrom its final location and floating it into position, withlimited interference to port operations. The decisionbetween the options of extending or improving a port isoften governed by considerations as to the possibility ofuninterrupted use of existing facilities.

439. The choice made is thus a matter of economic,operational and engineering analysis in each case, butthe modern trend seems to be away from locked basinswhere possible. The advantage of the operational flexi-bility afforded by free access to the open sea is gen-erally considered to outweigh the disadvantage of theincreased capital cost involved.

5. NAVIGATIONAL AIDS

440. The alignments of the straight reaches of achannel are often delineated by at least two masts onshore ahead of the approaching vessel, clearly visibleby day and provided with lights at night.

441. The boundaries of the navigable channel aremarked by fixed markers or floating buoys. The latterare more common in deep offshore channels but in ariver system the former are frequently more econ-omical. Buoys must be able to withstand wave actionand must remain visible at all times.

442. Systems of buoyage vary around the world andit is therefore important to establish which system isappropriate at a particular port. Essential advice is

available from the national lighthouse authority. coast-guards or navy departments in most countries.

443. The principal considerations leading to thechoice of spacing of the visual aids for shipsapproaching and leaving a port are:

(a) The configuration of the channel;

(b) The incidence of low visibility:

(c) The usual sea condition in the channel;

(d) The presence of cross currents and winds.

Closer spacing of buoys will be required at bends and litbuoys are required if the port is to be approached byships at night.

444. A new port will frequently require a mainlocation beacon or lighthouse, and considerationshould also be given in the general planning to radarreflectors. which ships can locate, port radar to monitorand control ship movements and radio communicationbetween ship and shore.

445. Advice on these specialist navigational ques-tions can be obtained from the International MaritimeGrganization (IMO) which has its headquarters inLondon.

6. ECONOMICFACTORS

446. The capital cost of marine structures can varywith the cube of the depth while, in the case of dredgedchannels and basins, the greater the depth the greateralso the maintenance burden, perhaps proportional tothe square of the depth. Decisions concerning thedepth and width of channels and basins. and the num-ber of berths, should therefore usually be made onlyafter thorough economic studies of each situation.

D. Dredging

1. INTRODUCTION

447. The removal of soil from the sea-bed or riverbed to provide greater depth of water in the approachesto ports and adjacent to quays has a long historv. Asthe size of ships has increased, the dredging of existingports has become increasingly important.

448. Great advances in dredging technology havebeen made in recent years, and various types of dredgercurrently used are described in section 3 below.

449. Dredging itself is essentially an excavatingoperation, but the selection of the correct equipment isvital in achieving economy. All dredging activity callsfor special consideration of the nature of the ground tobe dredged, the best means of removing soils and theoptimum work programme. Both capital and main-tenance dredging must be considered.

2. SITEINVESTIGATION DATA

450. The site investigations particularly requiredfor dredging work should provide data on tides and

85

bathymetry, on wind, waves and currents and on thenature of the materials to be dredged, their in situstrengths, particle size distribution, degree of compac-tion and, in the case of silts, settling characteristics oncedisturbed. In all cases, standard classifications of ma-terial to be dredged should be used.

451. Section B above describes the carrying out ofgeneral investigations, of which those for dredgingwork form a part.

3. TYPES OF DREDGER

452. The following types of dredger are usuallyavailable for contract dredging work, and the mech-anics of their operation are illustrated in figure 31.

(a) The bucket dredger. The modern bucket dredgercomprises a continuous chain of buckets mounted on aladder adjustable for depth. Each bucket discharges itsload at the top of the ladder, into chutes which directthe material into a hopper barge.

Bucket dredgers are best confined to work in shel-tered locations and are useful for fairly accurate trim-ming of the bed. They can deal with some hard materialbut large pieces in the bucket can cause serious delays.

(b) The grab dredger. The grab dredger is usually aself-propelled vessel with a hopper and a grab crane. Asimpler version which requires attendant barges issimply a crane on a pontoon.

(c) The dipper dredger. Excavation is achieved bymeans of a forward or rearward-facing shovel mountedon an arm suspended in front of the pontoon body,which operates by digging into the underwater ma-terial.

(d) The suction dredger. The basic components ofthis type of dredger are a pontoon hull which housesthe pumps and engines, a suction pipe suspended fromthe vessel to the sea-bed and a delivery pipe from thepumps to a dumping area or, in some instances, tobarges.

Only small granular material can be dredged by suc-tion and it is common for this type of dredger to beequipped with a rotating cutter on the end of the suc-tion pipe. Cutters can be designed to suit the particularmaterial to be dredged and cutter suction dredgers canremove sand and gravels, medium stiff clays and, withthe addition of special cutting teeth, stiff clays and softor broken rock. Output, however, varies considerablyaccording to material type and conditions. Neverthe-less, this cutter suction dredger is now the most usualdredging equipment for capital work and is particularlysuited for reclaiming purposes.

(e) The trailing suction hopper dredger. The trailingsuction hopper dredger is a self-propelled vessel withsuction pipes suspended from one or from both sides.The dredged material is delivered through the suctionpipes to the hopper. When the hopper is full, the vesselproceeds to the dumping ground.

This type of dredger is widely used in the main-tenance of channels, where its ability to manoeuvre as aship is a distinct advantage. A further advantage of thistype of vessel, when compared with the other types

discussed, is its ability to remain effective in roughwater and offshore locations. It is, however, suitableonly for relatively loose materials as would be found inmaintenance dredging.

4. DREDGEROPERATION

453. The selection of the most suitable dredger de-pends upon the material to be dredged, the depth ofdredging, the quantity and disposition of the material,the location of the dumping ground, the rate of produc-tion required and also on whether the dredger mayhave complete or partial possession of the waterway.

454. The programme and sequence of the dredgingoperations require careful consideration. If possible,dredging should commence in a location which wouldbe least liable to siltation from later dredging. Timingof the dredging activity relative to the construction ofother parts of the project, some of which, such asbreakwaters or groynes, may give shelter or affect silta-tion, must be considered in the overall planning of theproject. Timing may also depend on local seasonalvariations of tidal currents and winds, which can renderdredging activities much easier in one season than inanother, especially in estuaries. A further factor whichmust be borne in mind is the date of the start of opera-tions at a new port, which may be in advance of thecompletion of the whole project so that the construc-tion requirements of, or the need for access to, particu-lar berths will influence the sequence of dredging.

455. The removal of solid rock constitutes a special-ized dredging activity in that some means must befound to fragment the rock before it can be lifted fromthe sea-bed by one of the conventional dredgingmethods described above. Usually a bucket or grabdredger is used to remove rock debris, but suctiondredgers have also been employed to remove suffi-ciently fragmented rock.

456. The most commonly employed method ofrock-breaking under water is that of drilling and blast-ing, although jointed rock with thin bedding layers mayalso be fragmented by a heavy chisel or a pneumatichammer on the rock surface.

457. Drilling and blasting under water is a special-ized, slow and expensive operation and many trials maybe needed to obtain the right results for the dredgers tobe used. The dredging of coral or cemented sand causesfrequent problems. These can sometimes be easily frag-mented and dredged by a powerful cutter suction dred-ger. However, only careful investigation will showwhether this is likely, and massive formations may needto be treated as rock before dredging.

5. RECLAMATION

458. It is of considerable advantage if the dredgedmaterial from a port project can be used for reclama-tion projects, but only certain granular soils are suitablefor this purpose. Silts and clays are generally muchmore difficult to use. A thorough geological andgeotechnical survey of the extension area is required to

86

FIGURE 31

Five types of dredger in ecmnnon use

S E L F - P R O P E L L I N G B U C K E T D R E D G E R

b) crane

SELF-PROPELLING GRAB HOPPER DREDGER

NON-SELF-PROPELLING DIPPER DREDGER

N O N - S E L F - P R O P E L L I N G C U T T E R S U C T I O N D R E D G E R

SELF-PROPELLING TRAILING SUCTION HOPPER DREDGER

ensure that the existing subsoils can support futurebuildings.

459. The settlement behaviour of the fill materialshould be carefully analysed and monitored before con-struction is permitted. Pre-loading through the con-struction of embankments may be needed to achievesettlement within a reasonable period before buildingsare erected. Geotechnical analysis will generally pro-vide the correct solutions.

460. An important aspect in project planning is thebalance of dredging and reclamation, and this must beassessed in each case with a view to economy.

6. ECONOMICFACTORS

461. In assessing dredging costs it is important toremember that in many places large equipment must bebrought from far afield to do the work, with a conse-quent heavy mobiiization cost. The quantity of dredg-ing required for any particular scheme therefore has apronounced effect on the overall unit rate. For a mod-est amount of work it may be found economical toemploy simple equipment such as excavators on barges.Even though their working costs and productivity areless favourable, the saving in mobilizing the less sophis-ticated equipment can more than offset the less effi-cient performance in the field.

462. Such judgements are difficult to make and areoften best resolved when tenders for the work are in-vited, but during a project study the various factorsmust be considered so as to permit a realistic estimateof dredging costs to be prepared.

E. Breakwaters

1. DESIGNDATAREQUIRED

463. Where there is insufficient natural protection,breakwaters are needed in order to form an artificialharbour. Breakwaters deflect, reflect or absorb theenergy of swell and storm waves which would otherwiseenter the harbour area, and thus provide an area ofrelatively calm water.

464. The chief information needed for the design ofbreakwaters is the height and period of the storm waveslikely to occur. The normal practice is to choose a de-sign wave that represents the maximum wave measuredduring a storm which statistically will occur once in SO

many years, for example, once in 100 years. The likeli-hood of waves breaking against the structure is also afactor of importance in design. Data about the prob-able daily maximum wave must also be collected inareas of continuous swell, since this may have a signifi-cant effect upon the cross-sectional design of the break-water.

465. The determination of the design wave requiresthe study of available oceanographic and meteorologi-cal data. It is preferable that direct recording of waveheights and periods should be made at the port site, butthis is not always possible within the time available.

466. As waves are generated by winds, an estimate

of wave activity can be made from wind records. Localreports of storm occurrence also assist in building up astatistical picture of the waves which can be expected.Tide and storm surge water levels should also be re-corded or estimated, as waves are affected by waterdepth near port entrances.

467. The foundations of breakwaters warrant care-ful geotechnical investigation. Boreholes must be madeand soil and rock samples taken over an area suf-ficiently large to allow variations in the position of thebreakwater to be considered, and the possibility ofscour of the sea-bed for some distance in front of thebreakwater to be investigated. The strength and settle-ment properties of soils under a proposed breakwaterrequire study to depth at least equal to the width of thebreakwater base, since weak soils at depth may beoverstressed by a large structure. Weak soils at thesurface may have their bearing capacity enhanced bythe placing of a blanket of sand or gravel on the surfaceprior to construction of the breakwater.

2. ALTERNATIVETYPESOFBREAKWATER

468. Breakwaters may be in the form either of anoffshore island or of an arm projecting from the shore.The breakwater may present a vertical or near verticalwall or a sloping surface composed of variously sizedblocks. The two types are illustrated in figure 32. Thestructure may be submerged below sea level at some orall tide levels.

469. In the past, vertical- or near vertical-facedbreakwaters often comprised two walls of masonryblocks laid in horizontal, well-bonded courses with rockrubble fill placed between the walls. In later years, con-crete blocks replaced expensive masonry and, more re-cently, reinforced concrete caissons have been used.The caisson is constructed in a dock and then usuallyfloated to its final position and sunk on to a preparedsea-bed or blanket of rock rubble. Some form of inter-locking between the individual caissons is usually re-quired. Another approach is to precast the caissons onland, then to transport them along the already com-pleted length of breakwater and to lower them intoposition by means of a large cantilevered gantry crane.

470. Rubble mound breakwaters vary in the type ofprimary armouring used. These breakwaters are ofbasic trapezoidal shape in cross-section, with a moundof smaller-sized rock called the core. Graded stonearmouring is placed on the slopes and on top of thiscore. On the outside face of the breakwater, whichdissipates the energy of the storm waves, the largestprimary armour is placed. Many breakwaters of thistype with natural rock primary armourmg have beenbuilt and much published data is available.

471. In cases where it would be uneconomical toprovide rock of adequate size, artificial concretearmour units are employed. Considerable research hasenabled many specialized shapes to be evolved withhigh efficiency in resisting wave attack. In its simplestform (a concrete cube), artificial armour is a substitutefor rock fill, but many of the special units have beendesigned to improve interlocking between units, while

88

Examples of breakwaters

A. Verrrcall~ faced breukwurrr

providing the maximum voids in the armour layer todissipate wave energy. Examples of artificial armourare shown in figure 33.

472. While designing the cross-section of a rubblemound breakwater, the source of rock fill should beinvestigated for quality and output. An assessmentshould be made of the likely proportions of rock whtchcan be obtained from the quarry so that these propor-tions can be matched in the finished structure and wasteof certain sizes minimized.

3. DESIGNPROCEDURE

473. A preliminary assessment of breakwater re-quirements can be made by drawing possible break-

89

water layouts on a chart and estimating their effective-ness in intercepting anticipated wave attack. The effec-tiveness of the proposed breakwater layouts in reducingwave heights within the harbour can then be verified bymodel testing.

474. An element of compromise is usually foundnecessary between the most effective hydraulic solutionto exclude wave energy from the harbour. and the easeof access and berthing of ships. The types of ships andmethods of cargo handling need to be known so thatresidual wave activity in the port can be matched to theshipping requirements.

475. The design of the breakwater mass against thepossibility of overturning is fairly straightforward, butthe possibility of sliding on the foundation is frequentlyless easy to provide against. Measures to ensure an

F I G U R E 3 3

Examples of various artificial armour units

Cube Tetrapod

TrioodDOIOS Akmon

adequate factor of safety against the latter type of fail-ure may take the form of providing a sheet pile curtainor an additional build-up of material against the insidewall of the caisson.

476. A disadvantage of vertical-faced breakwaterslies in the scouring action on the foundation which maybe set up by the refraction of waves from the face of thewall. This aspect should be carefully examined. Never-theless, an approximate guide is that if the erodible bedmaterial is situated at a depth of less than twice thewave height below the lowest water level, scour needsto be carefully guarded against.

4. CONSTRUCTION

477. The two major types of breakwater discussedin the preceding sections require totally different con-struction methods and plant.

478. The core of a rubble mound type of break-water is commonly constructed by end-tipping progres-sively from the shore, but careful checks are neededagainst segregation of the rocks which may occur dur-ing loading and tipping. A large crane can then travelalong the top of the core mound to place the upper corerock to finish the profile and then to place the outerarmour layers of rock and/or artificial armour. A float-ing crane can be used but is economical only in areas

where severe sea conditions are rare. Similarly, thelower part of the core can be placed in position frombarges.

479. The caisson type of breakwater involves con-struction processes which usually take place off site.The caissons, which are made of concrete and haveclosed bottoms, are usually constructed in a dry dock oron a launching area on shore until the walls haveattained sufficient height to allow the caisson to float.When the walls have been completed to the requiredheight, the caissons are towed to the breakwater loca-tion where they are sunk on to a prepared sea-bed. Atime of minimum current and wave activity should beselected for this operation. The caissons should befilled with material, usually sand, as soon as possibleafter sinking to give the earliest full weight against waveaction.

5. ECONOMICFACTORS

480. The selection of a particular type of break-water also depends on such factors as the availability ofmaterials, plant and labour. A vertical wall breakwaterwill place different demands on these factors than atrapezoidal rubble mound breakwater.

481. The rubble mound breakwater will requiremore material because of its shape. Thus in an area

90

which has an ample supply of rock strata capable ofproviding large primary rock armouring, this type ofbreakwater would be preferred. A major expense is thelarge crane required for rock handling. which is nor-mally written off against the cost of the project. Forshort breakwaters this results in a high unit cost. Thisform of breakwater does not require a large pool ofskilled labour.

482. The vertical wall breakwater in the form ofcaissons requires less material. Reinforced concreteprovides the armouring and sand or gravel can be usedas the fill material. More modest equipment is requiredbut facilities are necessary to tow the caissons into posi-tion for placing, Such facilities, for example tugs, nor-mally have a use in the port. To prepare the necessaryforms to construct the caissons, a more skilled pool oflabour is required.

F. Quays and jetties

1 . INTR~DUC~-I~N

483. A distinction must be made between heavystructures on which cranes and large vehicles can oper-ate, and light structures which can only support pipe-lines, conveyors and light vehicles, The heavy struc-tures-interchangeably called quays and wharves-canbe either marginal (i.e. parallel to the shoreline) or inthe form of piers which project from the shore. Thelight structures, which also project out to deeper water,are called jetties.

484. A jetty is economical where the depth of wateravailable for the ships calling is available only somedistance offshore. It is suitable for bulk cargoes-dry orliquid-where the jetty head in deep water accommo-dates the specialized loading or unloading equipmentand the cargo is conveyed ashore by pipeline or movingbelt along the jetty approach. A jetty is unsuitable forgeneral cargo, where storage area near the ship is im-portant, unless a high tidal range makes it the onlyeconomical solution.

485. In any project there will be a variety of en-gineering possibilities which may call for either the im-provement of outdated facilities or the construction ofnew facilities in accordance with modern standards. Inthe case of new structures, known engineeringapproaches can be utilized, but for the improvement ofold facilities there are usually factors which impose con-siderable restraints on technical options and each casehas to be considered as a special problem.

486. Using on-the-spot materials can often be asuitable and more economic solution. It is advisable ineach construction project to identify such possibilities,rather than merely to adopt methods used in industrialcountries. For example, in some cases jetties can beconstructed with local wooden piles. or with bamboopiles air-driven into the mud. Another example of theuse of local material occurred in the development of abulk terminal. By designing heavier foundations whichused local material, the use of locally produced steel,which required a greater cross-section and was thusheavier than stronger imported steel, was possible. Thissaved the country a great deal of foreign exchange.

91

2. QUAYWALLS

487. Several forms of construction are available,each suitable for certain conditions. They include theblock-work retaining wall. the anchored bulkhead walland open-piled marginal quays, as described below.

(a) Block-work retaining wail

488. This type of wall, shown in figure 34A, re-quires a firm, non-erodible foundation, preferably rockor a stiff clay, but a rock blanket over loose ground canbe used to prevent scour.

489. Such a wall can be built up from individualblocks, usually placed under water. Among the poss-ible variations are solid block-work, in which the blocksare laid in horizontal courses, slice-work, in which theblocks are laid on sloping courses which allow the quayto accommodate settlements. and hollow block-work,which reduces the weight of unit to be handled. If dryconstruction can be used for the wall, then mass con-crete in situ construction is very suitable.

490. Concrete caissons can be used for quay walls,either by floating pre-formed boxes into place and sink-ing them, or by constructing a box in the final positionand excavating inside it until it sinks to the desiredlevel.

491. The suitability of each of these gravity wallsdepends greatly on ground conditions. Block-work andfloating caissons would normally be used only wherethe quay is built in water which has a depth close to thefinal dredged depth. A caisson can be built in its finalposition where the wharf is at present dry land andwhere the ground above dredged level is soft.

(b) Anchored bulkhead wall

492. Anchored steel sheet pile retaining walls, asshown in figure 34B, have been widely used for quaywalls and are to be recommended particularly wherethe quay height required is not unduly great and wherethe soil is a medium dense sand.

493. Higher sheet pile quay walls can be obtainedby using special composite sheet and H-pile sectionswhich are now available. Other measures which may beused to reduce the bending moment in the wall are toemploy a double bank of tie bars or to form a relievingplatform above the sheet piling. Concrete piles can beused in this type of wall and in many countries wherethe cost of steel piling is high, since it has to be im-ported, concrete may give considerable economies.

494. However, concrete piles are heavier, more dif-ficult to drive and there are problems of ensuring asatisfactory seal against soil escaping between them.The purchase cost of steel piling may therefore still bejustified. Table 13 compares factors which should beconsidered in each case.

(c) Open-piled marginal quays

495. One of the most widely used forms of marginalquay construction is the open-piled suspended slab asshown in figure 34C and D. This form of quay may

93 I

92

Fender beam

In situ concrete structural topping

-Pre-cast reinforced concrete planks

; - - C a p p i n g b e a m Sand fill7

Graded filter

Concrete paving

Granular baseI-

Tubular rubber fenders-

~----------------

Sl0pe

S a n d f i l l

Rock bund

FIGURE 34 (concluded)

D. Open-piled quay wrth anchors, ryprcal cross-section

In situ reinforced concretecope and deck slab

\Pre-cast reinforced

concrete units

Tubular steel piles

include, in addition to normal vertical piles, raking (in-clined) piles and/or tie rods connected to anchor blocksplaced some distance behind the quay. This type ofquay is built over a rock-revetted slope (a slope facedwith harder rock) or over a rock embankment or dikewhich serves to retain the finer soils--usually reclaimedmaterial-behind the quay.

496. In order to reduce the width of the apron slab,a low bulkhead wall is sometimes introduced at the rearof the quay to retain the upper fill material. A varietyof construction techniques is available in steel, concreteor even, in modest structures, timber. The most econ-omical deck width and the pile spacing have to beestablished by examining different solutions in eachcase.

497. Where there is heavy vertical loading, such asfrom container or bulk-handling cranes, large-diameterconcrete cylinder piles may prove an appropriate solu-tion for the quay structure. In addition, the spacing ofcrane rails can influence pile spacing and should betaken into account when planning the quay dimensions.

3. JETTIES AND DOLPHINS

498. A jetty provides a berth some distance fromthe shore. A trestle structure or causeway joins the

Bedrock

Rock fill

.

Tie rods

nchorbeam

jetty to the shore and may carry a roadway, pipelines orconveyors. In certain special cases the approach struc-ture can be dispensed with by using, for example, sub-marine pipelines for oil, or cableways for bulk ore. Ajetty may be built in sheltered harbour waters to pro-vide a relatively cheap berth for specialized cargo ves-sels and in such cases a short approach structure is allthat is usually needed.

499. Alternatively, a jetty may be built offshore inthe open sea, with a long approach structure to reachadequate water depths. For tankers and bulk carriers ajetty can be an economical means of providing a facil-ity, but the hostile construction environment and theperiods when the berth is unusable because of weatherconditions must be taken into consideration before thissolution is adopted.

500. While a normal quay wall structure performsthe two functions of providing a berthing position forthe ship and a working platform for ship-working activi-ties, in the case of a jetty it is usually economical toseparate these two functions structurally. Therefore, aworking platform (or jetty head) carries bulk cargohandling equipment, pipe handling gear, etc., whileseparate berthing and mooring dolphins are providedto hold and control the ship (see figure 35). The plat-form for cargo-handling gear is then not required toaccept the horizontal impact from the ship berthing or

94

TABLE 13Comparison OF steel and concrete piles

High costUsually have to he importedRequre simple mspectton and works

quality certificates; cleamng andpossibl) sandblastmg on the sxtr

Comparaitvely light to handle androbust

Can withstand hard drwing

Readily extended by welding

Lmble to corrosion and require paint-mg, extra wall thickness or cathodtcprotectmn

the loading while it is berthed, as the ship makes con-tact only with the berthing dolphins.

501. Where the sizes of ships do not vary greatly, asat an oil or ore berth, berthing or breasting dolphins areusually placed on either side of the jetty platform at aspacing of about 0.4 times the length of the ship.

502. A group of raking piles with their tops held ina concrete pile-cap may form the dolphin, with rubberfenders on the berthing face to provide the necessaryresilience. Alternatively, a berthing dolphin can beformed by using a group of large-diameter tubes of hightensile steel driven into or fixed in the sea-bed. Theenergy absorption of such flexible steel tube dolphinscan be computed to suit the anticipated berthing energyof an approaching ship, and it is frequently economicalto vary the section of the tubes over their verticallength. The degree of fixity of the pile in the ground isimportant for such calculations and the soil propertiesmust therefore first be determined by a thoroughground investigation.

503. Mooring dolphins are provided at a jetty tosupport bollards for ships’ mooring ropes. A group ofpiles or some other such structure which will take bol-lard pulls, depending on ship size, of up to 100 andsometimes 200 tons. is used for this purpose. In thiscase the piles are set some way back from the berthageline of the ship. Where the jetty is close to shore with avery short approach, the mooring dolphins can be con-structed on the shoreline. Access for small boats car-rying ropes should be provided at mooring dolphins.

504. The jetty head is usually a simple piled struc-ture with fendertng for those small vessels or bargeswhich may use the berth. Steel piles with a reinforcedconcrete deck are often used for this type of structure.

4. SPECIAL TYPES OF BERTH

505. In addition to the quays and jetties normal inany port, a number of unusual berth types have beendeveloped for special shipping services. These are un-

Lou COSICan bc made on siteReqwre careful site checking of

mater& and workmanship

Heavy and careful handling needed

Careful drwng needed and risks ofcrackmg

Extension IS time-consuming OTneeds sophisttcated connections

Require little maintenance if wellmade and undamaged

likely to fall within the scope of planning and designingcommon-use port facilities, as they are usually associ-ated with a particular industrial development.

506. Bulk ores and petroleum are now transportedin very large vessels and it is difficult to extend existingports to include berths for such ships. Moreover, newsources of crude petroleum and ore are frequently inareas where no ports exist and so completely new facili-ties have to be set up.

507. While jetties may be extended a considerabledistance offshore, natural or artificial islands created infavourable water conditions offshore can prove moreeconomical. Cableways (for dry materials like ores) orsubmarine pipelines (for liquid products) replace theapproach causeway. Sometimes such islands have theadditional advantages of providing storage and facihtat-ing subsequent transshipment.

508. A further development in recent years for pet-roleum discharge has been the single-point mooring forlarge tankers, as illustrated in figure 36. The use ofordinary mooring buoys and submarine pipelines fortankers has long been known but, more recently, singlelarge buoys or fixed structures have been developedwhich hold the ship. There are a number of types, someof which include the hose connection within the moor-ing, others which separate the two functions, but themain feature of all such systems is that the vessel cantake up the most favourable position with regard to seacurrents and winds by rotating around the buoy.

509. The major advantages of such systems are thatdown-time due to weather is less than would be the caseat a fixed berth in the same location; capital outlay andcommissioning time are generally less; berthing iseasier, and the system is relatively easy to remove to anew location. These advantages may be offset by cost,maintenance problems and safety questions.

5. BERTH FITTINGS

510. The fitting required on a berth comprise fen-dering to absorb the energy of impact of the vessel,

95

.-

FIGURE 35

Typical jetty for large oil tankers

A. Plan view

B. Longitudinal elevationShlP landing tower

mooring devices to secure the vessel during its stay atthe berth, access ladders or landing steps for small ves-sels, and boats and services supplying the various needsof vessels in port. Fendering is discussed in more detailin section 6 below and the other features are brieflydescribed in the paragraphs that follow.

(a) Mooring devices

511. Mooring devices vary progressively in sizefrom those required for small boats to those for largebulk carriers, and include bollards, mooring rings,cleats and quick release hooks.

512. The most important and most commonly useddevice is the bollard, which should be a low cast-ironpost, shaped with lobes such that ships’ ropes may besecurely held. Although bollards are classified accord-ing to the loads at which they will fail, the design shouldbe such that failure takes place first in the holding-down bolts at a pre-determined failure load, the struc-ture itself thus being safeguarded.

513. Bollard capacities and spacings appropriate tocertain sizes of vessel are given in manufacturers’ litera-ture. For example, for 20,000 dwt cargo vessels, 50-tonne bollards at 25-metre intervals would be suitable.

Quick-release hooks are usually employed on large ves-sel berths and proprietary designs are available to suitthe requirements of the ship operators.

(b) Ladders or landing steps

514. Ladders or landing steps should be providedalong the face of the quay at about 40-metre intervals.They serve not only to allow access to vessels of lowfreeboard and to small boats, but also as a safety mea-sure for anyone who falls in the water. Ladders or land-ing steps are also necessary on isolated mooring dol-phins in order to allow access from the launch duringrope-handling operations.

(c) Services

515. The port can offer a number of different ser-vices at a berth. The most common facility is the provi-sion of fresh water. The water supply may be arrangedat metered hydrant pits spaced at intervals of 50 to 100metres along the length of the quay edge, fed by ringmains usually as an extension of the local water supplysystem. Any limitation on the fresh water supply pership should be specified in port documents.

96

Water area requirements for single-buoy mooring

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&Limit of manoeuvring area+--- /’

--_-/-

516. Water must also be available for fire-fightingpurposes. The use of fresh water, although it does leastdamage to cargo, may be expensive, and sea water canbe used. Special salt-water mains can be laid which areleft empty, to be charged with salt water in an emer-gency, by either a fixed or mobile pump installation.For a more effective system, pressure-charged mainsand automatic pumps for instant use may be provided.This shore-based fire emergency system augments theusual provision of fire-fighting equipment on tugs.

(d) Fuel butrkeritag

517. At some ports there is a demand for the provi-sion of ships with fuel. The alternative to using a fuel-ling barge or setting aside a special fuel berth is toprovide a fuel supply at the cargo berth, so that the shipcan be fuelled during its time at berth. According to theclasses of traffic expected, fuel oil. marine gas oil,marine diesel oil and intermediates may be required.Not every berth needs to be so provided, but fuel hyd-rants served by buried pipelines should be provided atconvenient locations. Blending valves may be neededand maximum and minimum supplying rates in tons perhour should be specified.

(e) Electrical power

518. It is not usual for the port authority to provideelectrical power to vessels, but depending upon thenormal usage of the ships calling at the port, this maybe required. In this case, electrical plug boxes would beprovided on the apron at each berth. Lighting of theaprons is needed for night operation and to avoid therebeing lamp posts which might obstruct cargo handling,lights are usually fixed on the transit shed. For an openberth, high light-towers away from the ship’s side arepreferable.

(f) Ship-to-shore telephone

519. Telephone communication direct from theship is an increasingly important service. Ship-to-shorepoints are usually provided at each berth, preferablynear either end to be conveniently placed for the ship’ssuperstructure. Ducts are placed in the apron with drawwires through which telephone cables can be drawnwhen they are needed.

6. F ENDERINGOFBERTHS

520. The impact between a berthing vessel and aquay structure could cause damage both to the vessel

9 7

.-. - -

and to the quay wall unless a fendering system, exam-ples of which are illustrated in figure 37, is provided toabsorb the impact.

521. In the case of a solid quay, such as one ofconcrete blockwork construction, the maximum allow-able force would be determined by the ship’s ability toresist permanent deformation, the wall being able tosustain much higher forces than the vessel, In the caseof open-pile designs the strength of the structure tendsto be the determining factor in fender design. In bothcases fenders must be placed so as to reduce the forceswhich are transmitted to a given part of the structure.

522. Fender systems vary from quite complicatedarrangements to virtually no fendering at all for someberths servicing smaller vessels. The most usual form ofmodern fendering is rubber in various shapes which canbe easily attached to the structure and designed to suitthe particular conditions. Timber fenders are alsowidely used, particularly for general cargo berths,although the maintenance required is often consider-able. A very economical possibility is to use large tyres,for example, from earth-moving equipment, suspendedfrom cables, as fenders. Such fenders can be suitable,along solid wharfs, for up to lOO,OOO-dwt ships.

523. The allowable berthing speed of a vessel isdependent on the size of the vessel, the navigationalskill of the mariner or tug master and weather andharbour conditions. A higher than normal velocityshould be selected as a design figure to enable the fen-ders and structures to cover all circumstances of berth-ing, but it is usually quite out of the question to designfor an accidental collision. Manufacturers of propriet-ary fenders produce specifications of their fenders’energy absorption data and tables which enable a selec-tion to be made.

57.4. Other types of fender would normally be de-signed as a mechanical/structural system to suit the par-ticular application. For specialized berths, the ship

,operators would normally have opinions on the suitabletypes of fender for their vessels and should be consultedwhere possible. The following types of fender, illus-trated in figure 37, cover the range of choice normallyavailable.

525. Fender pile systems employ piles driven intothe sea-bed along the quay face. Impact energy isabsorbed mainly by the bending of the pile. For highberthing loads the capacity is usually enhanced by theinclusion of a rubber block between the head of the pileand the quay structure and by connecting the piles withLongitudinal members to spread the load.

526. Hollow cylindrical rubber fenders are veryconvenient and economical, but because of their li-mited capacity for energy absorption are generally usedon structures that can absorb high-impact forces. Theyare easy to install, suspended by chains or steel cableand are easy to replace. To cope with both horizontaland vertical movements of ships, they are normally in-stalled diagonally. In ports with high tidal ranges, sev-eral rows may be needed. In some cases rubber fendersare placed between a timber or steel rubbing strip andthe quay wall. As the coefficient of friction of the ship’sside against wood or steel is less than it is against rub-

ber, the longitudinal forces are greatly reduced. Vari-ous other types of rubber fender have been designed toact in shear, in torsion or in bending and in some fen-ders rubber and steel are bonded together to act as aunit in absorbing energy.

527. Gravity-type fenders are designed to trans-form the kinetic energy of the moving ship into poten-tial energy by raising a weight. Three general typeshave been developed which act by a system of cables,by a pendulum or by trunnions. A typical example, ofthe many which have been used, is that in which a largeconcrete block is suspended below the quay deck bytwo pairs of cables. The front face of the block, suitablyfaced with a timber rubbing strip, acts as the berthingface. The impact of the ship forces the concrete blockto swing backwards and upwards until the ship hascome to rest.

528. Pneumatic fender systems are pressurized air-tight devices designed to absorb impact energy by com-pression of air inside a rubber envelope. One typefloats freely but is tethered by ropes between the quayand the ship. Another type is the fixed air block fender,which has high energy absorption and consists of anenclosed rubber cylinder into which air is pumped. Theassembly is bolted to the quay wall face.

529. Torque fender systems are designed to absorbthe berthing energy by plastic deformation of metals intorsion. A mild steel torsion bar is used in such a man-ner that it is twisted by the motion of the ship againstthe fender.

G. Engineering cost estimates

530. During the earlier stages of a port develop-ment project, the engineering studies aim at identifyingpossible solutions and providing sensible estimates fortheir capital and maintenance costs. As a project de-velops, the degree of confidence in the estimates willincrease as further knowledge becomes available andmore detailed design work is carried out. Contingencyallowances should be made at each stage, decreasing asconfidence increases. Only when the work is completedwill the final cost be accurately known. A pretence ofgreat accuracy in the early stages should be avoided,and usually a tolerance of + 20 per cent is perfectlysatisfactory for the economic evaluations, bearing inmind that traffic and shipping forecasts cannot be anymore precise.

531. The engineer should, however, seek to makeestimates for alternative schemes easily comparable. Itis often necessary to provide the economic appraisalteam with estimates for alternatives which may nothave been foreseen at the outset when planning fieldinvestigations. An example of this is when the option ofexpanding an alternative port arises. In such cases theengineer may need to do a rapid investigation ofanother site, without time to carry out a full field surveyand design appraisal. The engineer should not place arestriction on the number of alternative concepts anddesigns which the team generates, but should avoidembarking on too detailed an investigation before thelist of options has begun to be narrowed.

9 8

-

FIGURE 37

Examples of rendering systems

A. FENDER PILE

0. PNEUMATIC FENDER

B. DRAPED HOLLOW CYLINDRICAL RUBBER FENDERS

E. RUBBER ARCH TYPE FENDER

C. SUSPENDED GRAVITY FENDER

F. TOROUE F E N D E R

532. The basis for estimating engineering costsmust be defined by the project team, and it is fre-quently decided that present-day costs and benefits willbe used throughout. Nevertheless, the engineer mayneed to assess inflation rates in construction costs, foruse in the joint appraisal as appropriate.

533. The division of the cost estimates into propor-tions of local and foreign currency and taxation ele-ments is often needed, and the engineer may obtainguidance from the economists. Nevertheless, these ele-ments can be seriously influenced by whether a locallybased or foreign contractor is chosen. The engineermust therefore at an early stage acquire a sound know-ledge of the national construction industry and considerwhether the project would be within its competence, orwhether an international contractor would be needed,with a larger foreign exchange requirement.

534. It is important to consider the effect on costestimates of different construction phasings. For exam-ple, an expanding port may require further break-bulkberths in future years. To build, say, one berth everytwo years might appear a theoretically attractive solu-tion, but in practice a proper study of the relationshipbetween costs and phasing may indicate that theseberths should be built at the outset, with a furtherphase of berth-building commenced about five yearslater. A significant feature here is that mobilizationcosts would be much the same irrespective of the num-ber of berths to be built under any one contract. Esti-mates for project alternatives are therefore best pro-duced in two parts: the direct cost for each element of apackage, and the mobiiization cost for whichever pack-age is being considered added separately at the end.This facilitates the manipulation of a variety of alterna-tive estimates in the economic comparisons.

100

Chapter VIII

ENVIRONMENTAL AND SAFETY ASPECTS

A. Introduction

535. Any port development project requires thatport authorities should take into consideration econ-omic and technical aspects. to which should now beadded environmental and pollution prevention. Thelatter. which are sometimes much more exacting thantechnical and economic considerations, can lead theplanner to alter the project.

536. The transport, the handling and the storage ofdangerous goods in a port area require that specialmeasures be taken to protect the port facilities and toensure the safety of the people working on the port’spremises or in the vicinity. Usually these measures con-cern port-operational aspects and involve the enforce-ment of safety regulations. However, within the con-text of the planning of a port infrastructure, one alsohas to consider the risks created by dangerous goodsthat may pass through the port and to adapt the portplan to these risks where possible.

B. Environmental aspects

1. GE N E R A L

537. Environment can be defined as all the physical,chemical, biological and social factors likely to have aneffect directly or indirectly, immediately or later, on allliving beings. Any blow to this system is defined as animpact and environmental surveys aim at finding, esti-mating and dealing with these impacts. When drawingup a port master plan, one should allow for all theseaspects.

538. Developing a port can entail substantial altera-tions in the physico-chemical and biological characteris-tics of the marine medium. For instance, the conse-quences could be:

(a) A reduction of the fishing stocks through the des-truction of the spawning grounds or the nurseries;

(b) Contamination or destruction of the shellfishbreeding beds;

(c) A deterioration of the bacteriological content ofthe sea, which can threaten recreational activities suchas swimming and boating.

539. Modern port operating techniques require theport planner to provide for large areas behind thequays. Port construction will usually result in the de-struction of the existing vegetation on these land areas.In addition. port operations can create waste, whosestorage should be controlled to avoid nuisances.

540. A port complex can be associated with an in-dustrial area which sometimes generates air pollution(sulphur dioxide, nitrogen oxide, hydrocarbons, dust)that cause inconvenience to people and damage tovegetation and buildings. Furthermore, noise IS a formof pollution which, depending on the level, can varyfrom annoyance to physical damage to hearing.

2. IMPACT smvms

541. The preparation of the port master plan willrequire a number of studies that will determine therequirements on one hand and the characteristics of thesite on the other to make the project match with thesite. The field survey should also take into account allenvironmental characteristics to gauge the impact ofthe project. The impact survey must be integrated intothe technical and economic surveys and be concernedwith the sea, land and atmosphere.

542. For the sea, the survey will determine thephysico-chemical characteristics, especially the grade ofthe water. A review of biological resources will beundertaken to prepare a list of all benthic resources,spawning grounds, nurseries, shellfish breeding bedsand primary production areas.

543. A special survey will be required to assess thedredging impact, to select the dumping grounds fordredged products and to control the damage. The dis-posal of dredged material at sea is regulated interna-tionally under the Convention of 1972 on the Preven-tion of Marine Pollution by the Dumping of Wastes andOther Matter13. The dredging of a new area poses moreproblems to the marine environment than maintenancedredging in an environment that has already been dis-turbed. Dredging could have such far-reaching effectsas destruction of the habitat of benthic species. altera-tion of salinity, change of currents and increase in tur-bidity.

544. A comprehensive review is required of thefauna and flora on the land and their characteristics.The hydrological conditions of the site will need investi-gation to determine the effect on the water table of theexcavation of docks and channels and the possibility ofthe introduction of salt water into surrounding agricul-tural lands.

I3 Convention on the Prevention of Marine Pollution by Dumpingof Wastes and Other Matter (London, 29 December 1972) [IMOpublication. Sales No. 76.14.E].

101

3. OPERATIONAL HAZARDS

545. Spills or uncontrolled release of dangerousand harmful substances carried in bulk or in packagedform, such as LNG, LPG, oil, toxic substances andradioactive substances would give rise to serious safetyand health hazards as well as harm to the marine en-vironment. Ports should be provided with adequateequipment and materials for combatting pollution inthe case of emergencies. Thus, an analysis of pollutionrisks in the port area arising from maritime casualtiesshould be carried out. The analysis will also determinethe selection of berth sites to minimize the environmen-tal impact arising from accidents to ships.

546. Port planners should take into account the re-quirements of the International Convention of 1954 forthe Prevention of Pollution of the Sea by OillJ and ofthe International Convention of 1973 for the Preven-tion of Pollution from Shipsls. Regarding the provisionof adequate facilities to receive and treat wastes fromships, planners should ensure that the necessary instal-lations are supplied; an IMO publication on the provi-sion of reception facilities in Darts could be used as aguide for assessing such need?‘.

4. PORT INDUSTRIAL AREAS

547. The planning of a port industrialalso take into consideration environmental

area mustand pollu-

tion prevention aspects. Particular attention should begiven to liquid and gaseous discharges. A survey of theprojected growth of the industrial zone should belinked to an estimation of the quantity and quality ofthe pollutant discharge. This would be followed by asurvey on the absorptive capacity of the receiving area?for example, inland drainage basins or the open sea.The surveys will set the dumping standards to be laiddown for industrial companies.

548. Although the physico-chemical treatment ofindustrial liquid effluents at the plant outlet is usuallyefficient, it is often desirable to consider the establish-ment of an effluent-collecting system in the master planwith a common effluent and sewage purification plant.

102

549. To control the effects of atmospheric pollu-tion, works may be planned with respect to the prevail-ing winds and to the relative location of urban areas.When there is a large concentration of industries, amonitoring system of atmospheric quality can be set upin strategic locations.

550. The question of industrial refuse should alsobe dealt with at the master planning stage. The plannercan reserve areas of limited use for future dumpingsites. Consideration could also be given at this stage to

I4 International Convention far the Prevention of Pollution of theSea by Oil (London, 12 May 1954), amended in 1962 and 1969 (IMOpublication, Sales No 81.06.E).

l5 Internatmnal Conventmn for the Prevention of Pollution fromShips (London, 2 November 1973) (IMO publication, Sales No.74.01.E).

Lb IMO Gudelines on the Provision of Adequate Receprion Facili-ties tn PO&, 4 parts in 3 volumes (Sales Nos.: Part I, 77.02.E; Part II,80.03.E, Parts III and IV, 78 12.E).

the establishment of a conditioning or disposal plant forspecial refuse.

551. Thermal pollution can be limited by setting amaximum temperature of the discharge of coolingwater. The use of sea water for cooling can result inchanges to its chemical and physical properties and thiswater, when discharged, can have positive or negativeeffects on all organisms living near the discharge.

552. Finally, the planner should draw up specifica-tions outlining the obligations of industrial companiesin the environmental field. They will include regula-tions on the treatment of liquid and gaseous effluents.The landscape development and the industrial environ-ment can also be subject to regulations to assure asattractive as possible a visual aspect.

C. Dangerous goods

1. GENERAL

553. National or international regulations give dif-ferent definitions of dangerous goods. Most of the timethey refer to lists of substances regarded as hazardous.The lists which are most commonly used are:

(a) The IMO International Maritime DangerousGoods Code (IMDG Code)” in which dangerousgoods or substances are divided into nine classes ofdecreasing risk (class 1 being explosives);

(b) The list of substances numbered by the UNCommittee of Experts on the Transport of DangerousGoods’“.

554. Generally, a dangerous substance can be de-fined as any substance that threatens the safety ofpeople and of facilities by fire, explosion, combustion,toxicity, infection, radioactivity, corrosion or pollution.Also, any substance that presents risks during its trans-port in case of shock, contact with water or air, orcontact with other dangerous substances is classified asdangerous. The term also includes an empty receptacle,portable tank or tank vehicle which has previously beenused for the carriage of a dangerous substance, unlesssuch receptacle has been cleaned and dried or has beensecurely closed, if the nature of the previous contentspermits this with safety.

555. Planning for the reception of dangerous goodsin a port can be summarized as follows:

(a) Take an inventory of the risks involved;(b) Investigate the preventive measures to take to

reduce the risks;(c) Consider the measures and actions to be taken in

case of an accident.

” The IMDG Code (1977 edition including amendments 1-13) ispublished in 4 loose-leaf volumes (Sales No. 77.01.E). The IMO alsopubhshes annual supplements incluchng amendments to the Code.

I8 Transport of dangerous goods, 3rd rev. ed. (United Nationspublication, Sales No. E.83. VIII.1).

-

2. INVENTORYOFRISKS

556. The handling of dangerous goods at generalcargo terminals generally cannot be avoided, as thisoperation is part of the normal flow of goods throughthe port. In most ports the general cargo terminals areclose to built-up areas.

557. The greatest risks for the population centresare associated with handling of poisonous gases andliquids. The introduction of special tanks and contain-ers has significantly reduced the accident rate as com-pared to the use of conventional drums and crates. Thestorage of flammable substances also creates a risk forthe port area. In general, the area affected by accidentswith dangerous goods in the general cargo trade issmall.

558. When dangerous goods are handled as bulkcargo. the port must be designed to receive the ships atspecial berths with handling equipment and shore-based storage facilities specially planned for the dan-gerous products. The nautical risks associated with col-lision or stranding can be catastrophic for transport ofdangerous substances in bulk.

559. The loading and unloading operation of dan-gerous goods in bulk is more accident prone than gen-eral cargo because of the absence of protective packag-ing. Cargo-handling and safety devices need thereforeto be designed with the utmost care. Risks to be consi-dered with the bulk storage of dangerous goods in theport area are:

(a) Natural events: earthquakes, floods. storms,lightning;

(b) Human factors: operating errors, aeroplanecrash, sabotage. accidents in adjacent industries, fire;

(c) Deterioration of the storage system through useor age.

3. PREVENTIVEMEASURES

560. Accident frequency can be reduced by the in-troduction and strict enforcement of codes, guidelinesand procedures for all parties concerned. The guide-lines, will refer to the packaging. handling and storageof the goods and should be based on study and experi-ence. There is a wealth of regulations. particularly fromthe IMO, that stipulate structural and operationalsafety standards and procedures applicable both toships and shore facilities. The need exists for excellentcommunication between ship and shore to co-ordinateactivities during loading and unloading operations.

561. One of the most common measures in portplanning is to set safety distances that separate thehandling and storage of dangerous goods from otherport areas. The safety distances to be maintained aresubject to the quantities and the properties of :he dan-gerous substance involved and tend to be greater forbulk handling and storage than for packaged products.

562. While no firm and comprehensive guidelinesexist for these safety distances, order of magnitude fig-ures may be given for specific products. For the hand-ling of crude oil and gasoline. an explosion danger zone

103

(with an explosive gas atmosphere) will be createdwhose size will depend on the rate of loading and un-loading. The minimum distance to be maintained froma crude or product berth to offices, general cargo ter-minals or passenger terminals is around 1.000 metres.For LPG. which is heavier than air and very explosive,the minimum safety distance to vulnerable areas is esti-mated to be in the 3.000 to 4,000 metre range. LNG,due to its less explosive nature, would require a smallersafety distance than LPG.

563. Nautical aspects were discussed previously inthis handbook. However. crude carriers and liquefiedgas carriers are amongst the biggest ships a port mayhave to receive and the dangerous nature of their cargocalls for:

(a) Ample space for safe navigation within the portarea;

(h) Adequate navigational aids: pilotage, towageand line-handling facihties;

(c) Traffic restrictions during navigation of thesevessels such as limited times and tidal wmdows for en-tering and leaving port, or one-lane traffic;

(d) Location of berths to make the collision withother vessels impossible.

564. Specific safety measures for packaged danger-ous goods are mostly in the operational and not theplanning field. Certam dangerous goods, for exampleexplosives, may be restricted to berths which arereasonably isolated and near the port entrance to allowships to be towed out in case of fire. Often mooringbuoys may be used for the transfer of explosives andother dangerous cargo to lighters outside the porr area.

565. Crude oil and product terminals should begrouped together as much as possible in reserved sec-tions of the port area, as should liquid gas terminals.Whenever feasible. traffic lanes should be separated forpetroleum vessels and other traffic. It is preferable tolocate berths in distinct basins which can be easilyclosed by floating booms in case of spills or other acci-dents.

566. Dangerous goods as general cargo can bestored by separation into limited lot sizes. Alterna-tively, a special area or shed for the storage of all dan-gerous cargo may be planned. Such areas will complywith special standards of construction such as fire-proofmaterials, a large number of access points and specialfire-fighting facilities.

567. For bulk cargoes there may be a limitation onlot sizes and on separation of these lots. For example,this may be done by the construction of an embank-ment around individual tanks containing dangerous li-quids. As many terminals are owned or rented andoperated by private or semi-governmental companies,the port authority will have to set safety regulations andcheck that they are followed.

568. Finally, the port authority will require a reg-ulation for the declaration of all dangerous goods enter-ing the port area. In addition, an easily retrievable in-formation source which gives the properties of all dan-gerous goods is essential.

4. PROVISIONS FOR ACCIDENTS

569. Provisions for nautical accidents consist mainlyof means for life saving, assistance in case of collision orstranding, tugs, fire-boats, and lifeboats. A wholerange of pollution control equipment. such as disper-sants, booms and recovery vessels, may have to be pro-vided.

570. For onshore accidents the port authority needsto provide:

(a) The necessary infrastructure (fire hydrants, tele-phone lines, access routes, fire-fighting equipment andmedical centres);

(b) Manpower trained in fire fighting, rescue tech-niques and first aid, with access to information ondangerous substances;

(c) A centre for the co-ordination of accident hand-ling which may well be combined with a general portco-ordination centre.

5. COST CONSIDERATIONS

571. The consideration of environmental, pollutionprevention and safety aspects in the planning of a com-mercial port may present substantial constraints andmay lead to noticeable alterations to the plans. Thealterations will be likely to involve a rise in the cost ofthe development. However, by considering theseaspects, the planner will define works which will fit inharmoniously with the site and which will usually beeasier to operate and will provide higher safety stan-dards. The ignoring of these aspects can lead to higheroperational costs and severe operating problems.

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Chapter IX

INLAND TRANSPORT

A. The system as a whole

572. The importance of the port planner’s lookingbeyond the port boundaries to the next transport leghas been emphasized in other chapters. He will oftenhave little authority in planning that leg, but shouldalways consider how goods are to be moved to andfrom the port and should try to influence the inlandtransport plan accordingly.

573. The starting-point is to consider what the mod-al split of the traffic in question will be, i.e.. what pro-portions will come and go by road, by rail and by water-way. This will often require a sample of existing con-signments to be examined. In judging whether themodal split is likely to change, the main factor will bethe extent to which waterway frontage, trunk road ac-cess and internal rail sidings are available at the ship-pers’ premises (factories, warehouses or mines). Thesefacilities change very slowly in view of the large invest-ments involved.

574. For each main traffic class (e.g. break-bulkcargo, containers, roiro cargo and each of the principalbulk commodities) it is next necessary to forecast itsown modal split and to link this with the future distribu-tion system. In each case the possibility of bottle-necksin the system is a primary concern. The system can beconsidered as a series of connected tanks with tapswhich have to be shut off when any one tank becomesfull, as illustrated in figure 38.

575. In accordance with this figure, if any one ofthe stores (port storage, inland depot or users’ stocks)becomes full, then in the short term the normal solutionis to stop the flow into it. This soon causes the preced-ing store to fill up. As regards the port import storage,port management has difficulty in turning off the shipdischarge “tap” when there is a hold-up in the system,and consequently the port feels the overload. In thelonger term, the solution may be to increase the size ofthe inland depots, but there is not often the possibilityof increasing the outflow from any store since thiswould need to be passed down the line and can onlyend with increased consumption, which is not a trans-port solution.

576. Such diagrams illustrate the chain reactionprinciple involved, but in reality there will normally bea branching network of depots and transport connec-tions, all of which taken together act to clear the portstorage, as shown in figure 39. The total tonnage ca-pacity of all these must be made sufficient to handlethe total ship discharge rate.

105

577 . In the case of barge transport, there may bethe option-particularly if the barges can be manutac-tured locally and cheaply--of allowing the barges them-selves to act as temporary storage. For export cargoesawaiting ships, this can be an economical solution com-pared with the cost of double handling through exportwarehouses. This approach is not likely to be possiblewith road or rail vehicles, where the cost in foreigncurrency terms is much higher per ton carried.

FI G U R E 38

The import flow

SHIPDISCHARGE

B. Trading practices

578. The second “tap” shown in figure 38, whichcontrols the flow of goods out of the port storage, is tosome extent under the control of the port management,Import consignments are normally cleared from theport only when:

(a) All duties and charges have been paid;

(b) Documentary formalities have been completed;

(c) Customs clearance has been given;

(d) The consignee wants the goods.

The port development plan should include as one ob-jective the encouragement of better practice in all thesematters.

FIGURE 39

Inland transportation network

Road

w----m R&l

- - - - Warerwq

579. Ideally, the physical flow of goods shouldnever be slowed down by delays with respect to financeor paper work. It will be a long time before this idealcan be achieved, but there are several actions that theport and the customs authority can take jointly:

(a) Agents can be required to provide a financialguarantee which permits consignments to be clearedbefore dues are paid. A single monthly invoice can thenbe sent for payment. The introduction of such guaran-tees or deposits can also help by limiting the number ofsuch authorized agents and so concentrating the clear-ance operation in fewer and more efficient hands.

(b) A routine organizational study of the flow ofdocuments will often show up possibilities of substan-tial simplification. Fears of reductions in clerical staffcan be to some extent offset by the need to transferstaff to the more useful control function mentionedbelow.

(c) Customs working hours and staffing levels arevery often too limited to handle the work smoothly.Steps may be possible either to increase the customseffort or to reduce the workload of customs staff bylimiting the sample of goods inspected or opened.

(d) Strict enforcement of the regulations concerningthe transfer of goods to long-term warehousing after alimited period, with reasonable storage charges in thewarehouse, can encourage consignees to clear theirgoods more quickly from port storage.

580. It is unfortunate that this area of the operationis sometimes subject to malpractices, for example, inthe form of illegal payments to ensure priority of com-pletion of the formalities. Managements may need tobe vigilant in this respect, and it may be advisable tointroduce systematic methods of recording the progressof the consignment documents, either manually or withelectronic data processing, purely to avoid such prac-

tices. This control function can be an important respon-sibility of a special department with adequate clericalstaffing.

C. Inland transport capacity

581. When checking that proper provision is beingmade for the inland transport capacity needed to matchthe forecast port throughput, the port planner shouldlook both at the vehicle and barge fleet and at the routecapacity required. Both of these are heavily dependenton the inland distribution pattern.

582. It is not sufficient to calculate the number andtype of vehicles and barges which will be needed perday to bring or take away the daily loading and dis-charge tonnages. This figure will show what the hand-ling, marshalling and administrative needs are, and arethus a first step in planning the layout. But they givelittle indication of the transport problem because theyleave out the vehicle journey time. For example, toclear 1,000 tons a day to the adjacent city area may callfor about 42 local delivery vehicles of b-ton capacityfitting in an average of three round trips a day, whilst toclear the same 1,000 tons to an inland depot 600kilometres from the port may call for about 200 vehiclesof 20-ton capacity taking four days to make each roundtrip. The distribution pattern and the route capacitydetermine not only the number of vehicles and bargesneeded but also the type of vehicle and barge and theport handling facilities. The number and type of vehi-cles and barges should be roughly calculated, and theregional transport planner asked to confirm that provi-sion of the vehicle fleet is included in the regional plan.The daily road, rail and barge traffic forecast for theport and the design surface loadings can also be dis-cussed.

106

The rffecl of introducing intermediate depots

583. When looking several years ahead it should beremembered that the growth -in traffic volume com-bined with the spread of industrial and urban areas arevery likely to cause basic changes in the pattern of in-land distribution. One of the major effects, which hasstrong repercussions on the port, is the need to intro-duce intermediate depots to separate trunk-road trans-port from local distribution.

SX4. This effect is illustrated in figure 40. Whenthere is a change from the one-leg pattern to the two-leg pattern, the type of vehicle serving the port is likelyto increase in size and cost and will therefore demandfaster servicing in port to match its shorter journey timein order to reduce unit costs. This is a similar trend tothat in shipping.

S85. Long routes tend to justify rail transport andin this case an option open to the transport planner is tointroduce a third leg: this enables the port to load cargo

on to road trailers. which are then taken to a railheadand carried by means of a “piggy-back” or “kangaroo”system using rail flatcars to the Inland depot. ln addi-tion, this method removes pressure from the road net-work. This can be an economical system combining thebest characteristics of short-haul road transport andlong-haul rail transport. The port sees only the smaller.short-haul trailers. as shown in figure 41.

D. Vehicle access

586. Traditionally, general cargo berths haveworked a mixture of indirect cargo (vm the transit shed)and direct cargo (loaded or discharged direct to or fromrail wagon or road vehicle at the ship’s side). Thts suf-fers from certain drawbacks:

(a) The rail and road vehicle movements on the quayinterfere with each other and with other operations;

(h) The rail track when not recessed causes circula-tion problems on the apron. which slow the movementof other vehicles and operating equipment;

(c) With the exception of large consignments ofhomogeneous cargo such as bags, the rigid planning ofvehicle availability at the right ttme is difficult to main-tain, with the result that direct working generally slowsdown the ship operation.

587. These problems have led to an approachwhich, although at first sight it appears restricttve. ismore flexible and smoother in operation. This is toprevent any external vehicles’ access to the apron fordirect delivery. Through the introduction of a transfersystem using, for example. tractors and trawlers, to atemporary buffer area at the rail or road pick-up point,direct deliveries are still accommodated. The increasedcost for transfer equipment is balanced by the improvedworking surface of the quay and the reduction in delaysto ship working caused by the late arrival of vehicles.For berths dealing with large numbers of heavy loads tobe lifted on to or from rail wagons, tracks flush with theapron surface can be utilized. Figure 42 illustrates thetwo approaches in which the alternative approach has aboundary beyond which external vehicles are notallowed to pass.

FIGURE 41

Combined road-rail hinterland distribution network

.iTURE PORTFU

RAIL PlGGY-BACK

RAILHEAD

Trailer operationport to railhead

107

FIGURE 42

Limitation on vehicle BCE~SS to qua?

A. Traditronal approach

MARSHALLING YARDMARSHALLING YARD.c *-----------_ ~..c *-----------_ ~.

cj,-------------,cj,-------------,

RAILRAIL A.A. AA- - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - -

o s---------------- Io s---------------- I~5,,,,,,---------------~~------~~5,,,,,,---------------~~------~

1 II:I

(a) Traditional approach

B. Alternative approach

.RAIL

, rq - - - - - - - - d----------- - - - - - - - - m - - - - - *

PARK

PICK. UP AREA

LIMIT OF EXTERNALVEHICLE MOVEMENT

588. Another approach is to eliminate direct dehv-ery by working all cargo through enlarged transit stor-age areas. While this alternative removes the problemcaused by delays in the supply of direct delivery vehi-cles, the area requirements can be significantly in-creased as the transit time of goods wili increase.However, this approach smooths the demand on hin-terland transport and thus reduces the size of the vehi-cle fleet required to service the port.

589. The approaches eliminating direct delivery onthe quay introduce double handling, but this cost isgenerally more than offset by the faster ship turn-roundand the elimination of rail track, particularly in coun-tries where labour costs are modest. They also intro-duce the need for additional tractor/trailer units, butthese can be of a standard type and they will add flexi-bility to the operations.

590. In terms of labour requirements, the doublehandling introduced tends to involve a transfer of menfrom the quay apron to the transit area, rather than anoverall increase in numbers. Furthermore, the transitarea operation can make much better use of the laboursince the operation can be closely planned instead ofbeing dependent on improvisation owing to the unpre-dictable arrival times of vehicles and cargo, as in thetraditional method.

(b) Alternative approach

591. This question of more systematic planning isfundamental to modern operations. Because the shipoperation, which involves the need for intense workingfor short periods, is separated from the cargo arrivaland delivery operation, the latter can go ahead moresteadily, regardless of the peaks ui ship demand. Thishas the important effect of reducing the size of thevehicle fleet required to service the port. In this morestable system, planned operations are possible withoutundue demands being placed on middle management.

592. There is a residual fraction of cargo on abreak-bulk berth which, taken in isolation, would meritdirect delivery either to rail wagon or to truck. Oftenthis requirement can be overcome by resorting to over-side operations to lighters. The cargo can then be takento an older berth with the possibility of direct delivery.When this is not possible, the decision to accept thepenalty of not working this cargo directly may be morereasonable than to make a change of system whichwould place a penalty on all the rest.

E. Through-transport systems

593. The principle of separating the ship operationfrom the onward transport operation applies with even

108

greater force to container and ro/ro operat ions .Although it would he attractive to the consignee. thetransport vehicle should not be allowed on to the apronto pick up a load. Whether the unit load is for genuinethrough transport (pallets or a full container load(FCL)) or is a less-than-full container load (LCL) fordischarging and re-routing in a container- freight sta-tion. the transfer to and from the apron must be carrredout under tull port control using port vehicles-nor-mally chassis, semi-trailers or straddle carrier-s.

594. In a new development there will be the oppor-tunity to take thus principle further and remove thecontainer freight station from the port area to a pointbetter situated for distribution to the urban area, thusfreeing valuable port land. as illustrated in figure 43.This applies parttcularly when the development is tar atradnional city port. When the proposal concerns theestablishment of a new port it is likely that the port willin any case be located away from urban development sothat the container freight station can again be located inthe port area.

59s. In the ideal through-transport arrangement,the port has no role as a storage or sorting point and isconcerned only with the transfer of unit loads from onevehicle to another. All formalities can then be com-pleted away from the port area. at a cleat-ante depotinland. as close as possible to the final constgnees. Inpractice this ideal is rarely attainable in developingcountries. since the proportion of FCLs is low, andtraditional commercial practices often demand re-consignment at the port. even for ongoing FCLs. Evenwhen an inland clearance depot is set up, it may bedifficult to persuade agents to transfer their officesfrom the port. and it will also be necessary to solve thelabour problems which arise from conversion of steve-dores into inland clearance depot staff.

596. One specific type of development can readilyuse the inland clearance depot concept. This is wherethe coastal region is not a centre of production or con-sumption, so that the port’s role is purely that of astaging-point en route to an inland region. In that casethere will he many advantages in transferring as muchof the operation to the inland point as possible particu-larly when the coastal climate is adverse.

F. Technical specifications

597. The warning on the danger of accepting manu-facturers’ claims without careful study of local technicalrequirements. which are given in other chapters, applyequally to land transport vehicles. There have beenserious problems caused by purchases of vehicles un-suitable for the local climate. terrain and road surfac-ing. For example, roads in many developing countriesnecessitate stronger suspension if trucks are to operatewithout excessive breakdowns. In any case. the short-age of maintenance facilities on a long route can justifythe setting up of a series of special roadside main-tenance depots and a co-ordinating organization tocontrol them.

598. In the case of rail, the future freight train islikely to be heavier and faster. Existing rolling-stockmay need replacement, track may need upgrading and

109

locomotives will need to be substantially more power-ful. The port planner should ascertain whether approp-riate specialist advice has been obtained in order toensure that the design port loadings are accurate.

G. Information systems

599. The co-ordination of inland transport move-ments with consignment movements wtthin the portarea and with ship operations can be a difficult task. Tokeep down the cost of tying up expensive vehicles, tospeed the movement of cargo and to make good use ofport storage, it is advisable to give special attention tothe method of transferring information about cargobookings, transport loading and ship itineraries. Theestablishment of a vehicle movement information cen-tre at the port can be a valuable means of improving theroad/sea co-ordination.

600. Where the road vehicles are in short supply. orwhere there is limited parking space, useful gains canbe made by setting up a vehicle booking centre. Thiscan be an office with sufficient telephone facilities topermit operatron of an appointments system wherebyhauliers collect specific consignments during specifictime-slots. so that waning is mmimized. Priority in en-tering the berth area is then given to trucks arrivingwithin the appointed time-slot (e.g. a half-hourperiod).

FIGURE 44

Loading bay configuration for road transport

Mlmmum Preferred I20

- 25

- 30

Minimum depth for manceuvr~ng- 35

Preferable depth for manoeuvring

H. Port access gates

601. It will normally be fully justified, to help inreducing the cost of pilferage and major thefts, to pro-vide a substantial security fence plus a patrolling secur-ity service under port authority control. Such fencesmust be maintained in good condition to be effective.The number of access gates should be reduced to theminimum and a rigorous gate pass system should beimposed. Staffing of the gatehouse should be adequateto provide several parallel check-out points, sufficientto keep vehicles moving without too much interruptionwhile exit permits are checked. In case of justified sus-picion or improper loading, the vehicle should be re-moved from the exit into a special bay foreseen for thispurpose next to the gate. Here the vehicle may beclosely inspected or reloaded without impeding themovements of other trucks. A separate gate may beprovided for the entry and exit of empty vehicles andprivate cars.

I. Loading bays

602. Loading bays provide a covered transfer areawhere goods requiring covered storage are loaded on toor unloaded from road vehicles. A sufficient number ofloading bays should be provided to handle peak trafficflows, and loading bays should be adaptable to future

45

conditions. The covered storage should have an over-hang of about 5 metres to allow work to proceed duringbad weather. The bays require a separate approachroad within the site area, a marshalling area wheretrucks assemble before moving into the loading bayposition, and a truck parking area or a secondary man-oeuvring area for trucks to wait prior to being directedto specific loading bays. The parking areas should besupervised by a traffic office and be used for truckswaiting for document processing.

603. Raised platforms are very useful and should beused in conjunction with a platform levelling device, astruck bed heights vary from type to type and betweenunloaded and laden conditions. Figure 44 illustratestypical raised loading bay layouts for B-metre articu-lated vehicles. The additional 5 metres reeommendedin the depth of the marshalling area permits acceleratedmanoeuvring by allowing articulated vehicles to passeach other.

J. Platform levellers

604. The correct choice and application of a plat-form levelling device is necessary for efficient opera-tion. The proper choice will increase the numbers ofvehicles handled and the pallet and fork-lift truck bat-

110

tery life, and reduce operating equipment tyre bills.The length of the platform leveller plate depends on theheight differential between the vehicle and the piat-form. The gradient should never exceed 1 in 10. Theleveller should be 1 .f;-2.1 metres wide and have a non-skid surface. There is a large variety of platform level-lers on the market, and expert advice should beobtained when making a selection.

K. Industrial doors

605. In addition to providing access to storagebuildings, doors have to provide security and weatherprotection. They can be sliding. sliding-folding or ver-tical rolling and are normally made of steel, aluminiumor timber. For power-operated doors, manual provi-sion for operation should be provided in case of powercuts.

L. Rail loading bays

606. Where possible, loading bays should be con-structed so that either road or rail vehicles can be used,for example by recessing the rail tracks to create a flushsurface and allowing sufficient clearance for rail wag-gons beneath the shed overhang. If this approach is notoossible. Dart of the transit shed loadine bavs will have

to be dedicated to rail traffic. The local rail authoritiesshould be requested to supply the information neces-sary for the designing of the platform. An overhangshould also be provided to minimize delays due to in-clement weather. Levelling devices should be used toadjust for variation between wagon platform heights. Atypical rail loading plattorm is shown in figure 45

FIGURF 45Typical rail loading platform

111

Chapter X

MAINTENANCE AND EQUIPMENT POLICY

A. General considerations

607. The standard of maintenance in ports mustkeep pace with the demands of modern plant andequipment. There are few ports in developing countrieswhich have managed to avoid accumulating a perma-nent pool of equipment awaiting repair. In some casesthe reactivation of such equipment would give the big-gest single gain in performance that management couldachieve.

608. Good maintenance is not cheap, and needs tobe considered at the planning stage. Substantial sumsneed to be provided for workshops. for spare parts, andfor ongoing maintenance. This is an extra expense but anecessary investment if the port is to function properly.

609. The care of civil engineering structures as wellas of buildings and equipment. both fixed and mobile,must be considered. The various kinds of modern hand-ling equipment used in ports. and particularly the largeritems, are naturally expensive, and the desire to mini-mize capital outlay often results in insufficient consider-ation being given to maintenance costs and to theadvantages of the standardization of equipment. Thus,designers are being pressed to design equipment for thelowest first cost, with insufficient emphasis on the costsof maintenance, and port engineers are under pressureto select the equipment with the lowest purchase price.Onlv by considering all the costs over the life of theequipment can the most economic selection be made.

610. Some of the mobile equipment used in ports isdesigned for use in the construction industry. Themanufacturer tends to design for that industry’s needs,producing equipment which can be used reliably andintensively (provided it is regularly maintained) for ashort life before being jettisoned. Similarly, in thefreight transport industry, trucks are frequently writtenoff after as little as three years’ intensive use. It is toooptimistic to expect that. in ports in developing coun-tries often far distant from the manufacturer’s support-ing services, and often in a more testing tropical en-vironment, items of mobile equipment can be keptgoing for ten years or more. In the absence of experi-ence to the contrary, ten years can be taken as themaximum useful life of much of the port’s plant, whilefor more sensitive mobile equipment, such as fork-lifttrucks, the maximum useful life is about five years only.For example, as regards fork-lift trucks, one port oper-ator in a developing country experienced some 45 percent down-time and in some areas of the port found itnecessary to keep a complete second set of vehicles asspares. The average life of a unit was only two years. Inthis particular instance the fork-lift trucks spent a con-siderable proportion of their time travelling with theirloads to and from the storage area.

611. There are two alternative policies for equip-ment selection: either ports must, as suggested above,accept short-life equipment and make regular provisionfor its replacement, or they must demand more robustand long-lived equipment for their own special needs.It is noteworthy that certain major European ports in-sist on the special strengthening and redesign of equip-ment to suit their own needs, and do not normallyaccept standard models. Ports that need only a limitedamount of equipment or do not possess the necessaryexpertise are strongly advised to call in a specialistmechanical engineerwho has spent many years in themaintenance of port equipment.

612. Among the factors to be taken into account inselecting equipment are the following:

(a) The demands that will be placed on the equip-ment in terms of utilization;

(6) The standard of driver training;

(c) The possibility of buying robustness by usingequipment of a higher rating than the job would other-wise demand:

(d) The general ease of maintenance:

(e) The choice of a design appropriate to low labourcost and high cost of foreign exchange, whenever poss-ible; for example, traditional bearings fitted with agrease nipple may be preferable to sealed pre-packagedbearings which, although they need no regular greas-ing, have to be renewed every year.

613. On large items of specialist equipment such asship-loaders and unloaders, together with their associ-ated extensive conveyor systems, provision must bemade for preventive maintenance to be carried out onan inspection basis. For example, once it is decidedwhat needs to be inspected and at what frequency, adefinite sequence for the inspections must be estab-lished. Any corrective attention needed should begiven by the inspector concerned during the shut-downperiod, or, where there is duplicate equipment, whenthe standby equipment is running. Any equipmentneeding major repair should be removed to the work-shops and a complete unit should be available for fittinginto position. Another form of preventive maintenancewhich has been used is a replacement policy. A decisionis taken from previous records on the length of econ-omic life of a11 parts subject to wear, and they are re-placed when they reach that age, irrespective of appar-ent condition. For example, it may be considered moreeconomical to replace all the lighting lamps at oncerather than having an electrician on constant patrol toreplace faulty lamps. It may similarly be consideredbetter to replace all fuses after a certain period of timehas elapsed.

112

614. On mobile equipment. preventive mainten-ance takes the form of a regular servicing schedule.Spare units have to be provided in order that a com-plete unit can be taken out of service while it is stillworking and inspected under ideal conditions in a prop-erly equipped workship. Broadly speaking, the main-tenance of mobile equipment falls under the followingthree headings:

(a) Lubrication and cleaning. to prevent wear andcorrosion;

(b) Adjustment. to keep the equipment in the condi-tion for which it was designed;

(c) Checking. to replace worn components beforethey fail.

B. The central workshop

615. As major repairs and overhauls will have to bemade to a wide variety of equipment. the central portworkshop will require layout planning in order thatwork can be completed and equipment returned to ser-vice with the minimum delay. A few salient pointsshould he noted. For example. the workshop should hedivided into mechanical and electrical sections and,when sophisticated equipment is beginning to be used,a small specialist electronics section. The mechanicalsection should mclude some provision for the fahrica-tion of light structural steelwork. pipework and plating.The main hay should have several entrances and beserviced by an overhead travelling crane of a capacityto suit the largest piece of machinery! to he handled. Anadequate area for benchwork should he provided witheasy access to the main bay hut not covered b,y theoverhead crane. In addit ion, the follo\ving ~111 beneeded:

(a) Sets of special tools for each range of equipmentto he serviced;

(0) A separate machine shop with adequate liftingappliances, with at least one lathe being able to turn thelargest component;

(c) A separate section to deal with mobile equip-ment with inspection pits and hydraulic lifts;

(d) An area with the appropriate equipment for thetesting and certification of ropes, wires. slings, etc.;

(e) An outside bay for the cleaning-down of piecesof equipment before they enter the shops;

cf) An adequate central store for all sections. con-trolled by a trained stores supervisor familiar with theprinciples of stock control and replenishment;

(g) Separate sections, with air conditioning, for themaintenance of fuel injection equipment for the dieselengines, and a battery room for the maintenance ofbatteries for fork-lift trucks;

(h) Administration offices with proviston for thecontrol of plant maintenance by means of modern wallcharts and a card index.

616. The overall cost of equipping such a centralworkshop (excludmg the cost of buildings) is likely tobe in the range of $2-5 million. Sufficient funds should

he provided for during the funding phase of the de-velopment project.

C. Guidelines for estimating maintenance costs formobile equipment

617. Table 14 sets out approximate annual main-tenance costs as a percentage of the equipment pur-chase price for a range of equipment based on Europeanexperience. Half of these costs in Europe represent thecost of highly trained labour. Ports in developing coun-tries vvill need to alter the labour cost element asappropriate, from the base used. namely $7 per hour(1973) for skilled electricians and mechanics. and toincrease the amount budgeted for spare parts to includefreight costs and to take account of the possibility ofmore rapid replacement in the local environment.

TABI r I?

Maintenance costs for mobile equipment: values adopted forestimating purposes

Moh1lr sane (10 year3 dl ?(I IIllMohde crane (25 tons al 2-i m)Straddle carrierFork-bf! t r u c k (l-U-ton)Forh-bft t r u c k (5ran)R o a d t r a c t o rT r a i l e r

D. Spare parts provision

618. The provision of an adequate store of spareparts is an essential part of a port investment proposaland must on no account he the place for budget econ-omies. The initial problem is to decide what spare partsare needed. bearing in mind that delivery delays anddifficulties in securing foreign exchange at a later datemight jeopardize port efficiency. Manufacturers’ listscan he very misleading and. if possible, guidance fromother ports using the equipment in similar conditionsshould be sought. Generally the user decides, from thelists provided and from previous experience, for howmuch of the equipment he should provide spare parts.The consumption rate under local conditions may hesubstantially higher than that foreseen by the manufac-turer. hut there will rarely be adequate local records toprove this. Where possible. the standardization of com-ponents will reduce the multiplicity of spare parts re-quired for different machines. For example. the use ofa standard range of electric motors, gear-boxes or fluidcouplings will reduce considerably the number of dif-ferent spare parts to he carried.

619. The type of component used can have amarked effect on the ratio of labour costs and spare

113

parts costs, since the use of alternative designs for thesame component can lead either to a throw-away pol-icy, with consequent heavy foreign exchange costs, orto a virtually indefinite life’, local labour stripping andoverhauling, with simple local manufacture of parts.

E. Maintenance manuals

620. In a number of cases, the maintenance manualprovided by the manufacturer will be insufficiently de-tailed. This is a result of the pressure to keep prices to aminimum, since such manuals can be very expensive toprepare. It would be wrong to demand too detailedinformation if the cost of this is going to be added to thepurchase price. Nevertheless, the following informa-tion should be provided, whether or not it is publishedformally in a manual:

(n) Operating instructions;

(b) Servicing schedules and required repair stan-dards;

(c) Spare parts lists, with identifying illustrations;

(d) Sets of drawings, especially of parts subject towear that may be manufactured on site, for example,renewable liner plates for ship-loader chutes;

(e) Specifications for any special tools and jigs re-quired for maintenance purposes.

F. Training

621. It is common practice to stipulate in the con-tract for the purchase of equipment a period of oper-ator training by the suppliers’ staff. However, the ques-tion of the training of maintenance personnel in thesuppliers’ workshops using the special tools to be pro-vided is often overlooked. This provision should bewritten into the contract where appropriate. Trainingthroughout the guarantee period (one to two years) isuseful in order to form a sound base of skilled staff.Trainees should be bound to a contract for a period oftime in order to retain their services in the port.

G. Defect reporting

622. It is advisable to set up a simple clerical systemfor recording each fault that occurs, to be used forestimating maintenance costs and future spare partsprovision, and for judging the comparative perform-ance of equipment of different makes and design. Thereport should come both from operators and fromworkshops, and should be regularly reviewed to deter-mine areas of design weakness which may require ac-tion by management and may be considered in futuredevelopment.

H. Maintenance of structures

623. While breakdowns in mechanical equipmentor electricity supply and the deterioration of roads andbuildings will be evident, the need for maintenance of

the basic breakwater. wharf and jetty structures is lessnoticeable but no less important. Although there aremany years’ experience in many ports, there is a sur-prising shortage of reliable cost data on port structuremaintenance. Yet a realistic estimate of maintenancecosts is essential to complete the economic and finan-cial appraisals of a proposed port project.

624. As part of the design studies, the engineershould consider the manner and cost of any necessarystructural maintenance in future years. Although alarge civil engineering project can accept a high level oftechnology in its capital investment phase, this is notthe case during its later life when maintenance and re-pair have to be done with local facilities.

625. Similarly, a structure of a certain design mayinvolve less capital cost but require more maintenancewith a resulting increased overall operating cost. Intheory, alternatives can be evaluated on an economicbasis. In practice, however, such calculations are boundto be imprecise. Therefore, the selection of the approp-riate design and provision for future maintenance is aquestion of judgement, in which both engineer and portmanagement must co-operate.

626. As a guide, table 15 gives suggested percent-ages of capital cost which should be allowed in esti-mates for yearly maintenance during the whole econ-omic life of the facilities. These are very general figuresand should be used only in the absence of local infor-mation.

TA B L E 15Maintenance costs for structural elements: values adopted for

estimating purposes

Quay structuresSteel sheet pilingSteel pihng with reinforced concrete deckReinforced concrete piles and deck

Rubber fendering ,.,....,.. ,.,.

EmbankmentsRock-fill

SurfacingConcrete aprons or roadsAsphaltOther surfaces (gravel, etc.)

Breakwater

0.301.000.75

1 .oo

0.75

1.00I.507 50

2.00

627. The arrangements for the maintenance of portstructures would normally be under the direction of theengineering department of the port authority. In someplaces it is found convenient to include such work in thegeneral responsibilities of a local engineering or publicworks department which is responsible for other civilengineering maintenance in the area. The precisearrangement is a matter for local decision but in anycase an adequate maintenance fund is needed and table1.5 indicates the order of magnitude of finance whichshould be made available.

-.

114

628. A most important feature of maintenance isregular inspection and reporting, upon which a routinemaintenance system can be built up, so that structuresare kept in good repair rather than allowed to deterio-rate for a long period. Accidents should be dealt withimmediately and here prompt reporting is essential, toallow dangerous conditions to be removed and clearlyto establish financial responsibility.

629. Most reinforced concrete structures will notneed maintenance until deterioration may be observedin the form of slight cracking. Cracks, other than hair-line cracks, should be sealed immediately to preventthe ingress of moisture and rusting of reinforcement.

630. Steel structures, on the other hand, normallyrequire regular maintenance, particularly in the moist,salt-laden air prevalent at most ports. A steel structureexposed to a marine environment is subjected to corro-sion which can seriously affect its structural integrity.Paint systems are used in many places, and recent re-search has resulted in many proprietory products withexcellent protective properties. Nevertheless, paint sys-tems deteriorate and suffer damage and are very diffi-cult to maintain in first-class condition, particularlyunder water.

631. An alternative is to design the structure takinginto account a rate of corrosion based on previous ex-perience. If an additional steel thickness is provided atthe outset, sufficient metal remains after some years ofcorrosion (say a 40-year design life) to carry workingloads without excess stress. As steel corrosion in amarine environment is an electrochemical process, spe-cial steels with copper additives have also been used, inorder to reduce corrosion. An alternative method iscathodic protection, whereby a sacrificial anode, nor-mally zinc, is positioned on or near the structure so thatthe iron in the structure becomes cathodic and does notcorrode. A second approach is to use a continuous elec-tric current to maintain a potential difference betweenthe structure and a separate anode.

632. The general quay fittings such as fenders, lad-ders and mooring rings, and the service facilities at theberth, require regular inspection; fenders, particularly,need to be replaced as soon as any damage or seriouswear has occurred. Spare fittings are normally kept inthe port authority’s store, ready for immediate usewhen required.

I. Equipment replacement

633. Equipment replacement may be needed ontwo accounts: gradual deterioration or obsolescence,and sudden failure. Generally, port equipment falls inthe first class and the problem consists of balancing thecost of new equipment against the rising cost of main-taining efficiency on the old. There is an age at whichthe replacement of old equipment is more economicalthan continuation at the increased operating cost. Theproblem for management is to determine a replacementpolicy such that the saving in operating costs resultingfrom the use of new equipment more than compensatesfor the initial cost of that equipment. There is no gen-eral solution to this problem but, given satisfactory costinformation, techniques have been developed to assisl

115

management in choosing the appropriate point in timeat which to replace equipment. The procedure consistsof determining the economic life for each type of equip-ment. The minimum cost solution is a starting-point,but it will be necessary to depart from this when themarch of technology makes equipment obsolete forreasons other than the cost of maintaining it. More-over, before placing an order for new equipment, it iswise to check:

(a) Whether improved equipment is available;

(b) Whether the opportunity can be taken to reducethe variety of types of equipment operating in the port.

634. For the purpose of comparing alternative re-placement policies, the discounted value of all futurecosts associated with each policy should ideally beknown, if such costs change with the age of the machineor, in the case of selecting between two machines, ifthey differ between machines. Future costs includelabour, power, maintenance and down-time costs. Caremust be taken, however, to exclude from each year’smaintenance costs the cost of repairs due to accidentaldamage, since these are largely independent of age andare not relevant for economic life calculations.

635. A satisfactory replacement policy based onhistorical cost records is one that replaces the equip-ment if the cost of replacing every n + 1 years is greaterthan the cost of replacing every n years. The mathema-tical basis for this policy and a numerical example aregiven in annex II, section F.

TABLE 16

Average length of economic life for port facilities and equipment

Breakwaters ........................... . . . .......Wharfs:

Concrete ................................. ...........Steel ........... ................................. ....Rubber fenders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Tugs . . . ....................... .....................Pilot launches . . . . . . . . . . . . . . . . . . . . . . . ..............Warehouses and sheds ................................Cranes:

Grabbing .......... ._. ..............................Quay .......... ......................................Gantry ................................ .......... . . .Mobile ...... ...... . . . . . . . . . ....................Mobile tower . . . . . . . . . . . . . . . . . . ......... ..........Floating ........................ ..... . . . ..........

Ship-loaders ............................ . . . . . .....Stackers and reclaimers . . . . . . . . . . . . . . . . . . . . . . . . . .Belt conveyors . . . . . . . . . ................... .......

Belts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Idlers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Mobile mechanical shovels ....................... . . .Straddle-carriers . . . . . . . . . . . . . . . . . . . . . . . . . . ., ......Tractors and trailers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Ro!ro ramps . . . . . . . . . . . . . . . . . . . . . . . . . . .Fork-lift trucks ................... .................Dump trucks ..... . . . . . . . . . . . . . . . . . . . . . . . . . .

50

402 510202025

202015

815202 52 520

3 ”766R

1586

J. Guidelines for economic life longer life justified by the lower labour cost is offset by636. Guidelines can be given on the appropriate the generally more intensive use under more arduous

economic life, for use when data on maintenance cost climatic conditions. The economic life takes intotrends are not available. Table 16 gives a set of figures account the risk of obsolescence. Some facilities couldfor a range of equipment. These figures are basically be used longer because of good maintenance, but arederived from European experience, but they are no longer in use due to the evolution of maritime trans-broadly applicable to developing countries since the port techniques.

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Part Two

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Chapter I

TERMINAL PLANNING CONSIDERATIONS

A. The changing pattern

1. Before setting out to plan the future terminalsand groups of berths, the port planner must have aclear view of the stages of development which a portnormally goes through, and of the particular stagewhich his own port has reached. Five phases of de-velopment are shown in figure 1 but other patterns ofdevelopment may also exist. In very rough terms, theblocks in these diagrams represent, in width, the num-ber of facilities or length of quay wall and, in height,the annual throughput of each.(a) Phase 1: Traditional

A group of general-purpose berths handling a mix-ture of break-bulk general cargo plus bulk shipments ofcommodities in packaged form (e.g. part-loads ofwheat in bags, or of oil in drums) or in loose form thatare packaged in the hold.(b) Phase 2: Bulking of dry cargo

When quantities of the bulk shipments grow to aneconomical level, they are carried loose in bulk car-riers, for which the port has to provide a separate drybulk terminal. At the same time the break-bulk facili-ties have to be expanded to handle increased generalcargo traffic.(c) Phase 3: Advent of unit loads

When unit loads such as pallets, containers or pack-aged timber begin to arrive at a port, they are in smallnumbers and are carried on conventional ships. At thesame time, the volume of break-bulk cargo begins todecline, and the volume of dry bulk cargoes reaches thepoint where separate terminals are needed for differentclasses of material.(d) Phase 4: Transitional multi-purpose terminal-__ .-_

With increasing volumes of unit loads, including thearrival of the first cellular container ships, special unitload facilities are needed. But since the way in whichthe traffic will develop is still uncertain, a flexible andadaptable multi-purpose terminal is needed which re-places part of the old break-bulk berths. Meanwhile,dry bulk continues to grow and diversify even thoughseveral different classes of material can be handled on amulti-purpose bulk terminal.(e) Phase 5: Specialized

Although in the case of a developing country it maytake a long time, the specialization of many forms ofcarriage is a continuous trend and eventually thevolumes in each of several specialized forms of unitload traffic, such as containers, packaged timber andro/ro, will grow to the point where they need separateterminals. A phase-4 multi-purpose terminal can easily

be converted into a specialized container terminalthrough the provision of additional and slightly differ-ent equipment. By the time phase 5 is reached, theresidual break-bulk volume will have shrunk consider-ably and older facilities for this type of traffic will havebeen closed down. Meanwhile, other major cargoes(timber, iron and steel) will be grouped in multi-purpose terminals of various types.

2 . It is important to note that experience in recentyears has shown that attempting to go direct from phase3 to phase 5 can give serious financial problems unlesstransition to specialized traffic is quite definite and pro-ceeding at a rapid pace. Investment in a special-purpose terminal before the pattern of traffic has de-veloped sufficiently means not only under-utilizationbut also a high risk of built-in obsolescence. Anotherform of obsolescence which mistaken investment canproduce is the continued building of conventionalbreak-bulk berths after a port has moved into phase 3.

B. Study of existing port facilities

3. Port development projects can be roughly di-vided into two categories: the building of an entirelynew port or of a major specialized terminal in a newlocation, or-a much more frequent case-a major ex-tension or renovation of an existing port. In both cases,a necessary step is to study the port facilities thatalready exist in order to determine their real capacityand to find out possible deficiencies in their design anduse.

4 . The first aim of the study is to see whether a partof the expected increase in demand could be met simplyby a better organization of the existing port facilitiesand minor technical changes or additions. The secondaim is to gather information on probable conditionsunder which the new berth groups or terminals willhave to be operated and to bring to light mistakes inprevious design to be avoided.

5 . However, the findings of the investigating teamneed to be treated with caution. The future traffic mixand technological conditions may be very different, anda theoretical possibility of increasing the capacity ofolder installations may prove difficult to achieve inpractice. It might be safer to consider the potential andunused capacity of an existing facility as a kind of safetyvalve to be used for coping with peaks of traffic orsudden increases in demand. These principles are dis-cussed in part one, chapter II.

6. The critical analysis of the performance at ex-isting port facilities must be made separately for eachgroup of berths or specialized terminals. The zone for

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P h a s e 1 -

Traditional

P h a s e 2 -

Bulking ofdry cargo

P h a s e 3 -

Advent of unitloads onc o n v e n t i o n a lships

P h a s e 4 -

T r a n s i t i o n a lm u l t i - p u r p o s eterminal

P h a s e 5 -

Specialized

Phases of transition of a growing port

PHASES OF TRANSITION OF A GROWING PORT

1 Break-bulk cargoes 1

PBUnit loads on

cmventional ships WC)

I Break-bu lk cargoes I

P B-fEzzqCont.L

sinus

general cargo is the obvious candidate for the start ofthe analysis.

C. General cargo berth group

7 . The work of the investigating team must beginwith an examination of port statistics in order to deter-mine how much cargo has been handled on the berthsunder study and what was the mix of the cargo, whetherpredominantly general cargo in break-bulk form, or asizeable proportion of bagged goods (sugar, rice, flour,etc.), or increasing quantities of unitized consignments(packaged timber and steel) and containers which mayrequire special facilities.

Dry hulkLcargoes IDry bulk Dry hulk3cargoes cargoer

A B

8 . A review of the statistics will allow the team todetermine what phase of traffic development the gen-eral cargo zone has reached, and whether port exten-sion plans should provide for the construction of addi-tional conventional general cargo berths, or a multi-purpose terminal, or whether traffic increases and tech-nological changes have been so rapid that the time isripe for the construction of specialized terminals forcontainers and dry bulk cargoes.

9 . Statistical figures will also give a first approxima-tion as to whether the actual throughput has amountedto a reasonable proportion of the estimated capacity ofthe berth group. Approximate figures rather than accu-rate calculations of berth capacity are needed at thisstage. In most developing countries a throughput of

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about 100,000 tons a year at a berth with a predominantproportion of break-bulk cargo can be obtained with-out unacceptable waiting times for vessels. When bag-ged cargoes and some unitized cargoes account for 30to 40 per cent of the total, higher throughputs of up to150,000 tons can be reached.

10. If the actual performance at the berth group hasbeen drastically below the approximate figures and yetthere have been periods during the year when shipshave had to wait for a berth, this would indicate thatserious deficiencies must exist, either in the way thegeneral cargo zone is managed, operated and equip-ped, or in the design and layout of facilities. The dutyof the team will be to scrutinize carefully all sources ofdelay and to find the reasons.

11, The findings of the investigating team should beexamined with a view to determining the best way ofco-ordinating the planned new facilities with the ex-isting group of berths. The possibility of activating anyunused older installations in full or in part should beassessed. A preliminary decision should be taken as towhether the prevailing trend towards a gradual increasein unit loads and containers would justify the construc-tion of conventional berths or of multi-purpose termin-als or even of a specialized container terminal. All con-clusions will have a tentative character at this stage butthey may help to put the port extension problem in aproper perspective and to indicate points which shouldbe analysed with particular care during the main phaseof port planning.

D. Bulk cargo terminals

12. The procedure for the examination of existingbulk cargo terminals is very different from that for theexamination of general cargo berths, but the aims arebasically the same: to find out whether there is a sub-stantial unused capacity and to detect mistakes in plan-ning and operating the terminal.

13. Terminals for the export of mineral ores mostfrequently require a considerable increase in the yearlycapacity owing to the rapid development of mining andto the discovery of new deposits. The first importantquestion facing port planners will be whether to build anew terminal or whether the existing one can be ex-panded sufficiently without a long-lasting interruptionof traffic. This question and the experience gained sofar in operating the terminal should be the subject ofthorough examination as a first step towards actualplanning. Attention should be focused on the followingpoints:

(a) Was the existing terminal planned in advance forconsiderable extension in case of need, and if so, wasthe procedure for extension properly documented?

(b) Are all phases of operations at the terminals suf-ficiently co-ordinated? If not. where are the bottle-necks and what exactly is their cause?

(c) Is the size of the stock of cargo for loading inproper proportion to the volume of traffic? Has it hap-pened that no cargo was available for loading upon thearrival of a vessel?

(d) Have the means of inland transport been ade-quate for the present traffic and suitable for a radicalincrease of capacity within the same system of trans-port, by road or rail?

(e) Have the dust-collecting and anti-pollution mea-sures worked in a satisfactory way?

14. Such a thorough examination of existing portfacilities is an indispensable preliminary step to plan-ning a major port extension. Time spent on this taskcan save much time during the main planning phase andreduce the number of alternatives to be closely studiedto a manageable level.

E. Terminal capacity calculations

15. The role of capacity calculations is to provide alink between the level of service achieved and threefactors: the demand placed on port facilities. the capa-city provided and the performance that can be expectedin local conditions. This task is also known as perform-ance analysis. The results of the calculations will berequired for financial and economic analyses.

16. When planning facilities, it is generally neces-sary to try out several different capacities with severaldifferent traffic forecasts, and to do this for differentpoints of time. A good method must therefore be quickand easy. The calculation will be used in various ways:for example, setting performance (productivity) andproposed capacity (number of berths) and varying traf-fic demand to determine the effect on level of service(ship waiting time). Alternatively, for a proposed wait-ing time, traffic and number of berths for the requiredproductivity can be determined.

17. All the calculations use linear equations exceptthe calculation of ship waiting or queuing times forberths. This is a complex mathematical expressionwhich for different assumptions may not have a numer-ical solution. For a planner unfamiliar with this branchof statistics, the possibility of errors is large. The use oftheoretical queuing formulae and computer simulationmodels have been used to estimate ship waiting time.

18. Both these techniques have dangers associatedwith them. Results from queuing theory are dependenton the statistical distribution of ship arrivals and shipservicing time. Research by UNCTAD has shown thatthe distributions often used are not the most accurateones. This point is discussed further in annex II, sectionD.

19. The main difficulty with computer simulation isthat the amount of effort needed often greatly out-weighs the gain in accuracy that the technique aims togive. The technique also suffers from the need for con-siderable data collection.

20. For the above reasons, the use of planningcharts is introduced in the handbook. The charts aregraphical statements of the linear equations and theplanner may prefer for greater precision to use theequations given in annex II. The relationship betweenberth utilization and ship waiting time is plotted by acurve based on queuing theory in the charts. but thewaiting time factors are also given in annex II and canbe used in the equations.

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21. However, it is recommended that the charts areused, first to obtain a clear understanding of the re-lationships and their sensitivities, and later as a cross-check on calculations. The use of the graphical methodforces the planner to estimate all the component figureswhich should be considered.

22. For mixed traffic, for example, when a bulkberth is also used for break-bulk operations if it is notoccupied by bulk vessels, the application of the plan-ning charts becomes difficult. In such cases a computersimulation may be justified, but it is more likely thatsimple calculations will give a satisfactory answer. Asimple approach would be to assume that break-bulk

vessels are shifted from the berth when a bulk vesselarrives. The charts may then be used to calculate theperformance for bulk vessels and also to determine theremaining capacity for break-bulk vessels. The waitingtimes for break-bulk vessels will, however, be difficultto determine.

23. The procedures for calculating the capacity ofeach type of terminal differ. The various proceduresare given in chapters devoted to the following groups:break-bulk berth group; specialized container terminal;multi-purpose general cargo terminal; specialized roiroterminal; barge-carrier terminal; dry bulk terminal; andliquid bulk terminal.

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Chapter 11

THE BREAK-BULK BERTH GROUP

A. Need for break-bulk berths

24. Some ports in developing countries, particu-larly the smaller ports, may still be in the initial phaseof development. For these countries it is possible thatconventional break-bulk traffic will continue to growfor ten years or more, thus justifying the building ofadditional traditional berths. In any case, there will bea substantial residue of break-bulk cargo passingthrough ports in developing countries for several de-cades at least, and old facilities will need improving orrenewing. For all these reasons, port planners will stillbe faced with the planning and design of the break-bulkberth group. Ports which conclude that there is nolonger such a need should refer to the chapters on themulti-purpose terminal and the container terminal, Inmany rapidly developing ports there might be a needfor both specialized terminals and conventional break-bulk berths. The latter should be planned for easy con-version to special uses. In fact, any new traditionalberths should be able to be converted to a multi-purpose facility.

B. The berth group

25. The term “berth group” has been used deliber-ately for break-bulk facilities, for the following reason.The planning of port capacity must always be on thebasis of the set of berthing-points which share the samestream of traffic. When several different berthing areascan deal with the same kinds of traffic, then-providedships can be equally serviced in each area-there is adisadvantage in restricting a group of ships to one area.This is because splitting a stream of traffic into severalseparate streams (say, according to region of origin)destroys the smoothing effect of the possibility of allo-cating ships to berths over the whole berth group in aco-ordinated way, and leads to longer waiting times.The way in which ports have grown has often led tothere being several distinct wharves or basins whichtogether form the facilities available for break-bulk car-go operations. It is the totality of these facilities whichforms the break-bulk berth group for which the plan-ning procedure is given in this chapter.

26. Where the operational staff systematically sendsome of the ships in the break-bulk traffic stream to oneberthing area and the rest to another, then this shouldbe treated as two traffic streams and two separate berthgroups. Separate traffic statistics, forecasts and capac-ity calculations should be made. This happens whenthere are two berthing areas of substantially different

depth and as a matter of routine deep-draught and shal-low-draught ships are berthed accordingly. The man-agement information system should distinguish be-tween these two traffic classes. Another example maybe where a particular berthing area is dedicated to shipson a given trade-route or conference. For operationalpurposes it must be accepted that such berthing policiesare seldom rigid and the segregation policy will some-times be broken according to the daily berthing situa-tion. However, in spite of this, it is better to plan thefacilities separately.

C. Economy of scale and berth occupany

27. The combining of the berthing plans for small,physically distinct groups of berths into one berthingplan for the stream of traffic results in a reduction inship waiting time. The greater risk of queueing whengroups of berths are treated independently arises as aresult of the possibility of a ship having to queue for aberth in one group at a time when there is actually avacant berth in another group. A numerical examplewill show the significant advantage of joint berthingplan, although the operations on each berth or smallgroups of berths may best be managed separately.

28. Let us consider two independent break-bulkgeneral cargo five-berth groups, each with an averageship service time of three and a half days and a shiparrival rate of one ship a day. Another way to considerservice time is the service rate, the number of shipsserviced over a period of time. For this example, theservice rate would be l/3.5 or 0.29 ships per day. Eachgroup has an average berth occupancy given by dividingthe arrival rate by the product of the number of berthsand the service rate which, for this example is 0.7. Thiswould give an average queueing time of 19 per cent ofthe discharging/loading time, which is close to the limitfor which a port should be designed (see annex II, sec-tion D, table VII).

29. If the traffic were combined and handled as asingle stream over the 10 berths, the berth group wouldnow receive two ships a day, but the berth occupancywould remain unchanged at 0.7. However, this sameberth occupancy on 10 berths gives an averagequeueing time of only 6 per cent of the service time, animportant increase in the quality of service and an in-surance against serious congestion during peaks.

30. As a quick guide, berth occupancies for conven-tional general cargo operations should be set so as notto exceed the figures given in the table below, whichare based on a ratio of ship cost to berth cost of 4 to 1:

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.._ -

1 4 02 5 03 5 54 6 05 6 5

6-10 7 0

Since port administrations of small ports would be re-luctant to accept a 4tMO per cent berth occupancy andthe resulting under-utihzation of port facilities andlabour, the retaining of an efficient lighterage servicewould be an economical way to allow the utilization offacilities to be increased without running the risk ofexcessive waiting time. The lighterage service wouldthen act as a safety valve for the handling of ships thatcould not be berthed alongside during periods of peakdemand. Investment decisions cannot normally bebased on these limits alone, however, and require themore detailed procedure described later in this chapter(see section G below).

D. Quays or moorings for general cargo-==L--

3 1 . Over the years there has been discussion as towhether a modern port should dispense entirely withworking general cargo ships at moorings. One view isthat working to lighters introduces double handlingcosts and increases the risk of damaging cargo, whichmakes the operation less economical than working atberths. The contrary view has also been held, namely,that moorings are a cheap and useful facility for sup-plementing, during periods of peak demand, the lim-ited number of berths that many ports are restricted toby space or funds.

32. There will in fact be circumstances when eachview is economically justified. The decision should bebased on the following factors:

(a) The importance to the shipowner of alongsideberthing, there being other reasons for preferringberthing than merely ease of cargo handling, for exam-ple, the need for bunkering and other port services;

(b) The relative price of land and of labour, whichcan bring the economic advantage either to berthing ora combination of berthing and working at moorings;

(c) The existence or lack of a large and well-organized lighterage fleet with labour;

(d) The local destination or origin of the cargo: forexample, cargo going to private shallow-draughtwharves or destined for onward transport via bargewould be best discharged to lighters at a mooring;

(e) The weather pattern at the port: it will generallybe possible to work at berths for more days in the yearthan at moorings.

33. The rate of working to and from lighters, forconventional general cargo or bagged bulk commod-ities, cannot be clearly said to be higher than the rate ofworking at berth. In general, the difference is notsignificant for certain cargoes, while for others berthworking is clearly superior. In addition, working atberth provides the opportunity to introduce a variety of

modern handling techniques which cannot be usedwhen working to lighters. This factor, together with theassurance of easier and more accurate tallying and re-duced damage, weighs in favour of berth working in anew development.

3 4 . The strongest case for working at moorings is toprovide a major port contingency capacity, even whenthe standard method is to work at berths. It is relativelyeasy to reintroduce working in the stream when trafficbuilds up above the immediate berthing capacity, pro-vided that a reserve fleet of lighters with labour andsome lighter-handling facilities are available.

E. How many berths are there now?

35. Port extension proposals are generally justifiedby comparing the level of service which is given by theexisting facilities with that which would be given byproviding additional berths. To do this it is necessary todescribe the existing facilities in terms of the number ofberths that they represent. Often this is not obvious,where there are complicated waterfront layouts. It isnot permissible to add up the separate lengths of quayin a berth group and from this work out the number ofeffective berths this total length represents. This willoverestimate the capacity, since the capacity of an ir-regular quay is usually less than that of a linear quay.

36. The correct approach is to use a map of theacutal waterfront layout to determine how many shipsof the average length for that traffic stream can besimultaneously berthed at the berth group. The portmarine superintendent or harbour-master should beconsulted. This number of ships can then be taken asthe number of berths for planning purposes. Wherethere are lengths of quay too short to handle averagelength ships, then these can be excluded and may beallocated to another traffic stream.

3 7 . The illustration in figure 2 depicts a case of oldfacilities where a planner could be misled into believingthat there are 11 berths, whereas there are in fact onlyseven for the forecast average size of ship. In this exam-ple there is a total quay wall of 2 km. The length ofquay wall excluding the end faces of piers A and C andthe inner face of slip E is 1.77 km. The theoreticalberthing capacity with the forecast average ship lengthof 160 m is 11 ships. However, the actual berthingcapacity, as shown, is seven ships, since it is not safe toberth more than four ships of average length in

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basin D, and berthing is so difficult in slip E that it isonly used for lighters and barges. The reason for thelarge discrepancy here is the unsuitability of the oldslip E for ships of this average size.

38. This example also shows how unreliable areoperational performance measures based on overallquay wall length. For example, if the whole 1.77 kmberthing length of this berth group were achieving anannual throughput of 1.05 million tons of general car-go, this would give 590 tons per linear metre of quay,which would generally be considered low. In terms ofthroughput per berth for the seven berths. this wouldbe better stated as 150,000 tons per berth, which isgenerally considered good.

39. The number of effective berths used in capacitycalculations will often be different from the formalberth numbering system. For administrative purposes,it will often be advisable to maintain distinct berthidentities, laid out, numbered, staffed and monitoredseparately, even when ships overlap berth limits. Thisshould not affect the planner’s capacity calculations.

F. Berth capacity calculations

40. The two major quantitative decisions for theplanner are:

(a) How many berths there should be in the futureberth group;

(b) How much storage space should be provided foreach new berth, and whether any additional storagespace is needed at existing berths.

Procedures for each of the decisions are set out below.

41. Supplementary planning decisions are, ofcourse. needed with respect to each of the following:

(a) The appropriate depth of water at quays ormoorings;

(b) The appropriate quay layout for the operationalplan proposed;

(c) The berth equipment needed;

(d) The appropriate level of manpower;

(e) The cargo delivery and receiving system.

G. Number of berths required

42. For the break-bulk cargo terminal, planningcharts I and II should be used for deciding the appropri-ate number of berths. The first chart (see figure 3)allows the planner to determine the berth-day require-ment (the number of days ships are at berthing points)and the appropriate number of berths required. Thesevalues are used as a starting-point for the second chart(see figure 4). which gives the expected ship time atport and can be used as the basis for a cost-benefitanalysis. The relationships used to prepare these chartsare given in annex II, section E.

43. The following three terms used in chart I aredefined as follows:

(u) Overall fraction of time berthed ships worked:for example, for a berth group working two eight-hourshifts on six days a week, the fraction would be(16 x 6)/(24 x 7), or 0.57:

(b) Number of commission days per year: the num-ber of days in the year on which the berth is availablefor cargo handling irrespective of the standard shiftarrangements. The following lost days would be ex-cluded from this factor:

(i)

(ii)

(iii)

(iv)

Days, on average, on which the berth is out ofaction for maintenance or dredging;

Days on which it is known that bad weather willnormally interrupt working completely;

Days on which the berth is occupied by non-cargo ships, for example naval vessels and pas-senger cruise ships;

National and religious holidays which cannot beworked under normal circumstances (note thatthe weekly rest-day is not excluded as it is in-cluded in the above fraction);

(c) Berth-day requirement: the total number of daysthat ships will be at berthing-points to work cargo. Forexample, 100 ships each requiring a berth for four daysgive a berth-day requirement of 400.

44. The procedure for the use of chart I is as follows(refer to figure 5):

(a) Enter the chart at point A on the scale indicatingaverage tons per gang-hour; the figure correspondingto point A should be taken from actual performancedata;

(b) Draw a vertical line down to the line indicatingthe fraction of time that berthed ships are worked, togive a turning-point B;

(c) Draw a horizontal line to the left from point B toreach the turning-point C on the line indicating theaverage number of gangs employed per ship per shift;

(d) Draw a vertical line down to the curve indicatingthe annual tonnage forecast, to give a turning-point D;

(e) Draw a horizontal line to the right to reach thevertical scale of berth-day requirement at point X. Thisvalue is the main output from this chart. for use withplanning chart II;

cf) Extend the line past X to the right to give aturning-point E on the curve indicating the commissiondays per year, then draw a line vertically upward on thehorizontal scale to obtain the approximate number ofberths needed (point F).

45. When a detailed breakdown of the componentsmaking up berth productivity is not required, the plan-ner may start at the left-hand horizontal scale (tons pership-day) and descend directly to point D. Tons pership-day at berth is a useful measure of performancewhich incorporates the first three factors (i.e. averagetons per gang-hour, overall fraction of time berthedships worked and average number of gangs employedper ship per shift).

FIGURE 3

Break-bulk general cargo terminal, planning chart I: berth requirements

/-

FIGURES

Break-bulk general cargo terminal, planning chart II: ship cost

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E x a m p l e o f u s e o f p l a n n i n g c h a r t I

128

Example o f use o f p lann ing char t I I

129

- -

46. The example of the use of planning chart Igiven in figure 5 has the following input data:Number of tons per gang-hour ,. 1 2 . 5Fraction of time berthed ships worked 0.6Number of gangs employed per ship 2.5Tonnage forecast 600,000Number of commission days per year 350

47. These inputs will give a mean ship productivityof 450 tons per day, and a berth-day requirement of1,330 days per year which requires approximately sixberths. However, this is only a rough indication basedon typical berth utilization and does not show the costof ship time in port. To obtain this cost, the berth-dayrequirement obtained from planning chart I is enteredon planning chart II (see figure 4). A similar method asfor the first chart is then used with the following pro-cedure (refer to figure 6):

(a) Enter the chart at point A on the scale indicatingthe berth-day requirement; the figure corresponding topoint A is obtained from chart I;

(b) Draw a vertical line down to the line indicatingthe number of berths (from chart I) to be tried out, togive a turning-point B;

(c) Draw a horizontal line to the left from point B tothe line indicating the number of commission days peryear, to give a turning-point C;

(d) Draw a vertical line down to the curve indicatingthe number of berths (the same number as at point B),to give a turning-point D;

(e) Draw a horizontal line to the right to reach theline indicating the average daily ship cost in dollars, togive a turning-point E;

cf) Draw a vertical line upwards to obtain annualship cost (point 5).

48. The procedure can be repeated with one moreberth and then with one less berth. This will give a setof values of total annual ship cost for the three alterna-tives. The separation into waiting time and service timehas been avoided in order to emphasize the importanceof planning only for total performance, which is thebest measure of the level of service given to ships.

49. The example of the use of planning chart II,given in figure 6, has the following input data:

Berth-day requirement ,... 1 , 3 0 0Number of berths Either 5, 6 or 7Number of commission days per year _. 350Ship cost per day $3,500

For the five-berth case the total time at port is 1,800days, while for the six-berth case the total time at portis reduced to 1,500 days. There is a further 75-day re-duction in ship time for the seven-berth case. Bearingin mind that losses due to scarcity of port facilities inthe event of an unpredicted turn for the better in acountry’s economic development could be many timesthe cost of an additional berth, these alternatives needto be evaluated. The planner would have to ascertainwhether the saving in ship time between the five-berthand the six-berth alternatives justified the investment inthe additional berth and, if so, then if the seven-berthalternative were justified. This would normally be donein a cost-benefit analysis as described in part one, chap-ter II.

H. Berth length‘-

5 0 . Once the number of berths required has beendetermined, the length of new berths must be set toenable cost estimates to be made. A wasteful traditionin port planning has been to use the currentlyfashionable berth length for a class of trafficirrespective of the local requirement. It is argued that itdoes not matter if the length used is not the economicoptimum since on a linear quay there is less meaning tothe individual berth. This, however, introduces yetanother error into the analyses of economic advantagesand disadvantages. Each port should consider for eachof its zones what is the most appropriate berth length,and for this it needs a broad analysis of the ship lengthsin the traffic stream in question.

51. The governing factor is the average ship lengthfor that particular stream of traffic. Experiments madeby the UNCTAD secretariat using different typicallength distributions show that there is a generalrelationship between the amount by which the averageberth length exceeds the average ship length and theamount of ship waiting time involved. This relationshipis given in figure 7 in the form of a correction factor tobe applied to the total ship time at port given byplanning chart II. With a safety margin of 10 per cent,there is no correction to be made. In this way the effectof providing a greater or lesser berth length can betested in the cost-benefit analyses.

52. The correction factor indicated in figure 7applies to all berth group sizes except for the singleberth, where the berth length must of course be that ofthe maximum ship length. The correction factor is notparticularly dependent on the number of berths sincethe economies of scale achieved by shifting vessels dailyto make the best use of gaps, on a linear quay, rarelyapply to more than a three-berth length.

I. Sensitivity studies

53. Each of the figures used in the input datashould have a sound basis. For example, the productiv-ity used must be based on a practical operating plan forthe berth, the fraction of time worked must be based onan agreed labour policy, and the number of commissiondays must be based on weather constraints and a berthmaintenance and dredging plan.

5 4 . There will often be alternative values for thesefigures, depending on other management policies andsometimes on other port investments. Planners shouldevaluate the costs or savings resulting from varying thevalues. Where there is a real choice involving relatedinvestment-for example, where the extension of abreakwater will increase the number of commissiondays per year-the various output values given by plan-ning chart II should be used to carry out an economicsensitivity study.

5 5 . Where the alternative value demands manage-ment action, such as a change to a new shift system, itshould be remembered that such a change may involvecosts either in extra staff, in upgrading existing staff, inhiring an external adviser or in higher pay for shift-

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Berth length correction factor for breah-bulk seneral cargo terminal planning

I I II I I 1 1 ,

0.96 1.00 1.02 1.04 1.06 1.06 1.10 1.12 1.14

AVERAGE BERTH LENGTH

AVERAGE SHIP LENGTH -BERTHING GAP

working. These costs should be set out in the economic of tonnage forecasts and the similar need to allow forsensitivity study in such a way that if this alternative is lost syacc in the st~e+Typical ratios are given in annex. .._” -“.chosen the necessary funds will be provtded. I. table I. For the estimated density. the net holding

volume required can be calculated; this is the theorett-cal volume forthe hi&i&r-ca=city if the cargo were all

J. Dimensioning of storage areasone consignment stackedin a’sojid block. To this-.,. ~.da.. .^volume must he -added an allowance for broken stow-I.._.. .- .--,.__.

56. Break-bulk storage areas should be planned in-age. that is. for the eca~space needed when constgn-

dependently for each type of area: for example. transitX&its are taken apart and’fhe various aems ;placedseparately. A typical figure would be a 21Lper centallowance, which has been incorporated in p~nr%iigsheds , ogenxeas and wsare-hws. A systematic

@iYZdure can be used for each type by the m.This procedure is summarized in figure 8 (phnmingchart III). and the relationships used to prepare thischart are given in annex II. section E. The variousfactors influencing the area-requirements are discussedbelow.

^ ~_. .L. _

57. Of the apnual tonnage worked over a berth.part will be for direct delivery aiidj@???&r store.

either in transit s-pen areas. The proportion.~-_^. .likely to follow each course, and thus the proportionlikely to pass through the $crrr.areas, must be esti-mated. This figure is the starting point for planningchart III. Next. the average transit time for the cargomust be estimated. Unless a great deal ofemphasis is tobe placed on cargo clearancs the pr”sent_tra~~-it--~~la!:should be assumed. ny&rage transit time is definedas the average time that elap?es between a consignmentbeing placed in the store and its removal from the store.This value can be estimated by sarnphng a number ofconsignments from storage ledge: -records. Normallysteps should be takenmce the q.erage transit de-lay tf it exceeds ten days. From these two factors therequired holding capacity in tons is-determined.

clart 711 The planner now has the voss holdi=s--=.--- .lLvolume required. which must be converted to the stack-~-...“-,-%%--- .._-mg area required..-----j_-___

59, For the cargo mix concerned, the ax%agestack-..--I_ng height must be estimated. For planning purposes.this height is the average of the stackkng heights of thevarious cargoes that make up the mix, in a fuil store.M e - ~ - - - -The stacking height is a function of cpargo type-andpackaging type. and these should be the determiningfgctors. In the case ofbreak-bulk car,gq. different com-modities may be stacked to a height from 1 to 3 metres,the average figure being 2 metres. A simple way toobtain average stacking height is to walk along the&and measure the stacking height every ten paces.From this height the stacking area required can be de-termined.

60. There may also be a choice to be made betweenthe cost of providing facilities for hi&S.-stacking andthe cost of the larger area requirements caused bylogger stacking. In this connection there are several con-siderations to be taken into account:

58 . Th~g~iremetrtra~ir, o r den-sjtvf the cargo mtx maktng up the traffic using*storagF?%G iiG?he%timated. Although the densityofis otten significantly different from thGT=age factol_nf that cargo, owing to the lost spaces m them?-the ship that carries it, it is usuwactoryG the latter, bearing in mind the levels of accuracy

(a) The cost of providing st,ng_e:yuipment-whichcan work to the full height chosen:

(h) The cost of building a store of sufficient height;

(c) The limitations impose?~bv lateral forces from’ - - - -thack.acting on the walls of the store:

(d) The limitations imposed by floor weight restric-- .h.___ _tiqns.

_“..._, I- ,__

131

-

Break-bulk general cargo terminal, planning chart III: storage area requirements

Floor weight restrictions are not generally critical atmodern terminals, is moreoften governed by uipmentand where shed lot but a check mustalways be n&&t& the smage area design”loading isconsistent with the floor slab desia,>pzification. Thefloor leading, in ton-$?iSii metre, is obtained bym-rig the maximum stacking height by the cargo&lezeLin tons per cubic metre.

.dvm.- F

61. The average stacking area required must be in-creased by an allowance for all space not used for stack-ing, for exarnp%?%-y-ways, offices within the storagearea, customs che6emg:golnts%$~&al amenities. Atthe early pl%ining stage when detaila&$%i%ve notyet been prepared, an average figure must be used. Fora break-bulk transit shed, a typical allowance would be40 per cent. This figure has been used in the planningchart to give the aLFf,%ge storage area required.

62. A reserve of storage capacity must be providedover and a~~“fh~~~;-~.~~ing capacity, to handle.+-~..~-~~-. _the variation in demand.

.t wdl rarely be economical to

provide a design capacity,to cope with the very highestspeaks of da%i.“the capacity chosen should besuthcient tor handlmg the majority of peaks or surges.- se--“--r

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0 /’ ,’/’

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For example, with respect to figure 9, which shows avarying demand on a store, it is clear that to design forthe average demand would be quite unsatisfactory.Whether the design capacity should be set at level A orat level B, for example, depends on the relative cost ofproviding and maintaining the extra capacity which isidle for a large part of the time as against the cost ofrunning out of capacity and having to take emergency

-* action to prevent or cure the resulting congestion.6 3 . Where the form of the variation is known-for

FIGURE 9

Variation in storage demand

132

example, where the size and frequency of the shiploads .,which give rise to it are known. as well as the hinterl:irK’transport movements-the cost calculation can hereasonablv accurate. and a design capacity can hefound which is an economic mi?iXCZ’Su’ueh calcula-tions will sometimes show that the cost of congestionwill he so much higher than the cost of idle storage thatthe best decision is to provide for the nmximum likelydemand.

64. However. when there is little knowledge of theexpected shape of the demand varration-for example.in a cpm~n-u_s~,.~inal-there is little scope forfindmg the .m%imum economic design. Here it is moreappropriate i’0 rely on-experience: The UNCTAD sec-retariat has examtned a number ot different cases andfound that as a general rule rt is desirable to provide anaddrtional 40 per cent as rese;ve.rapabilrty over andabove the basic capacity. Thr: margin IS applied rn addi-tion to the hwsgaces needed for access. b,roken stow-se-and administrative areas. To provide less than a 25per cent reserve would be unwrse under any circum-stances.

65. The average demand for space m a transit shedis a--mathemattcal concept, used as an intermediate stepin the calculations. Transit sheds in a port are similar infunction to lungs m that they draw cargo in and out.just as the lungs draw air in and out. Nerther are meantfor stor?ige. The maximum capacity of the lungs is theamount of air drawn in with a deep breath. Equally. thetransit sheds must be able to hold the maximum de-mand. The definition of the ma>imum. however, is dif-ficult as at any one time there is cargo from severalships in the shed and capacity is required for several.mminent ships Thus the average demand is calcu-+- _- -late and then the extra or reserve capacity is added onto take account of the variation.

K. Transit areas

66. The purpose of transit areas within the port isprimarily to provide a to harmonize thefaster ship-shore flow wer shore-inlandmovement. In addition. these areas provide a safe placefor checking the condition of all consignments and theircorrespondence with the manifest and bills of lading.a&for accomplishing the n%%s%y customs and deliv-ery formalities. In no event should transit sheds be usedfor lo-ng-term storage, which should be a function ofwarehousmg areas not adjacent to the waterfront.

67. A rough preliminary estimate of the requisitesize of transit sheds can be made on the basis of experi-ence of existing berths or in neighbouring ports. Whilethe length of the sheds is usually limited to about 110.120 metres by the average length of the berth [about160-180 metres) and the necessity of leaving wade ac-cess space between two neighbourmg sheds. there ismore freedom m selecting the width of the shed. Ex-perience in many developing countries has shown thatsheds should pt-eferably be not less than 60 metreswade, with 50 metres as an absolute minimum whenthere is a shortage of available space on land.- -

68. In most countries ample storage should he pro-vided in the open, especially when the rainy seasons are

-.

short. Vehicles and agricultural and road-buildingequipment do not require covered storage. nor do con-struction steel, oil m drumsMjFother goods. Asmuch storage in?% o-pen should be provided as localland conditions permit, wrthm, of course. some rcason-able limits. Open storage yards should be well markedand clearly separated from roads and parking and load-ing areas.-They should be kvelled and prop&y-paved.with adequate provisions fo%‘irainage of rainwater.

L. Transit shed design

69. In the selection of a design for the transit sheds,the following errors of design should be avoided:

(a) Insufficient width of shed, below the absoluteminimum of 50 metres, with a resultant shortage ofstorage space;

‘(h) An excessive number of interior columns sup-portrng the roof. which will unped?thentof mechanical equipment in addition to reducing theusable space on the floor;- - -

(c) Inadequate vetion and Ii htin making car-go handling and reading the mar!Fs slower and moredifficult:

--.--y-l1 _

(d) Poor quality of the fll, not smooth and resis-tant enough:

(e) An Insufficient number of doors. and poor sus-pension of doors so that opening or closing them isdifficult and slow:

(f) Waste of space within the sheds on offices whichcould be located on an upper level;

(g) Too solid and monumental a construction. un-suitable for alterations or dismantling of the shed andits erection on another site.

With the sole exception of the last point. all the de-ficiencies listed above may have an unfavourable effecton the efficiency ofoperations within transit sheds.

7 0 . w‘_ are not normally appropri-ate either for transit sheds or for port warehouses. Sin-g&sto.rey sheds. greatly simplify cargo handling Kd-obviate the need for expensive

+ndations and cargo

lifts. Various types of shed are shown m tgure 10 WE-%ate an mterior unencumbered by internal supportstructures. However. the complete absence of interiorc%rimns will result in a moie expensive structure than asTYed with a limited number of columns. which can beplaced in such a way as not to obstruct operations.

71. To achieve the goal of fiexibility in the face ofchanging terminal requirements, it is an advantage tobe able to dismantle a transit shed and re-erect it in adifferent location. This may be a factor in choosing theform of construction. A certain amount of material isdamaged in dismantling and re-erection. but normallynone of the m%i%%bers is affected. If the work isdone carefully. with professional supervision. the onlyloss may be the holding-down bolts and a few ~;z)gng_,~sheets. -c.. ,.&.

92. A further design pomt which affects the flexi-bility of future operations is the design for I-forms-at the Eg,_of the transit shed. For berths whichare expected to continue to be used for break-bulk car-

- -

133

FIGURE 1 0

Types of transit shed construction

PORTAL

PROPPED PORTAL

MANSARD

TIED MANSARD

An“A” FRAMES

goes for some considerable time, the rear-loading plat-form running~thg~-whole. length. of the shed ,is advan-tesztrucks may be loaded or discharged withoutthe use of fork-lift trucks.

13. A -s&which gives a level en-trance at the q.uay side and a raised &&for%he-7gihery side is useful if the sl<Fe zan be kept very$$?;a slope of 1 in 50 is often needed for drainagepurposes, but a slope of more than about 1 in 40 canmake stacking by fork-lift truck difficult. Thus, for theavsmil-board hdght, it will only be possibleto keep the slope acceptable in shed widths of 40 metresand upwards.

74. If the Shed-lon~~~~~~~glS~rrn is consideredunacceptable, %?-i?may be preferable to keep thesurface at one level and to use mobile load&La.mps,This point must be studied at t&%%“o~&ign, andthe cost of a sufficient number of mobile ramps must be-*..- -I.._added to the list of,&hS,eqm~rnent Included in theproject costs. For this form of shed, the shed floqr.,canbe sloped on both sides with a slightly raXS8%i?‘in thecent%This arrangement can help in saving c*gCj lyingon the other side of the rib from water damage in theevent of fire-fighting or washing of the shed..-.__ .-

M. Warehousing

75. Warehouse storage is needed:

(a) When the maximum cargo flow exceeds the stor-age capacity of a reasonably sized transit shed;

(b) Where the port wishes to engage in the commer-cial busines of long-term storage of cargo, for example,for cargo that must be aged, or cargo which is to besorted, packaged and sold from the warehouse.

7 6 . In deciding what is a reasonable size of ware-house it should be recognized that the transit shed andthe warehouse in the rear are complementary: it is theirtotal which makes up the storage capacity. In decidinghow to divide the total storage capacity between them,the following factors must be considered:

(a) In many developing countries the cost of thelabour needed to transfer goods to the warehouse is lowand the cost of quayside land is high;

(b) There is both a minimum space needed for satis-factory operations and a maximum shed dimension be-fore internal travel distances become too great;

(c) The financial incentive to consignees of avoidingthe cost of transferring goods to the warehouse can be auseful means of preventing excessive clearance delays.

N. Layout for deep-sea berths

7 7 . The modern break-bulk berth, especially in de-veloped countries, will be required to accept an increas-ing amount of palletized or equivalent (e.g. pre-slungor bundled) cargo. Very few pure pallet berths are like-ly to be needed, but the changes in break-bulk berthsmade necessary by the increasing size of ships entail thegradual incorporation of many of the operational char-acteristics of the pallet berth concept. These includeincreased berth length and the provision of a large totalterminal area including a wide, well-lit quay apron witha width of not less than 25 metres and preferably one of30 metres. If large numbers of containers are to behandled, then we are no longer discussing break-bulkbut rather multi-purpose facilities, which are describedlater. The need for better protection of most break-bulk general cargo results in the increase of the totalshed area.

7 8 . A typical berth layout for a modern break-bulkberth group handling conventional deep-sea liner traf-fic is given in figure 11. This diagram illustrates severalpoints:

(a) The concept of a self-contained zone where theoperations are planned and co-ordinated by a singlemanagement team;

(b) The substantial areas needed for operations, de-livery zones and vehicle parks and movement;

(c) The provision of offices for agents of all kinds inthe immediate vicinity of the operating area, to speedup the documentation and clearance of consignments;

(d) The provision of substantial parking areas fortrucks and for private cars;

(e) The clearly laid one-way road circuit;cf) The central road and rail delivery zone.79. Each shed, with an area of over 9,000 square

metres, will typically hold a maximum of 5,400 tons of

134

mixed cargo. For berths handling 100,000 tons per yearthrough the shed, this size of store would allow goodsto have an average transit time of 14 days on theassumption of 1 ton of goods per square metre of stack-ing area. The warehouse could be located further awaywithout serious disadvantage, or it could be replaced byan open storage zone if there were a high proportion ofopen storage cargo. If a large number of 15-metre-longtrucks were used for delivery, the road/rail deliveryzone would have to be widened. In all cases the railtracks should be set flush with the concrete surface toallow easy passage of road vehicles and wheeled portequipment.

80. In addition, space must be available in the areaof the rear of the berth for some auxiliary facilities suchas a small shelter for mobile equipment, sanitary facili-ties, changing rooms, a first-aid station and a canteen toserve the group of berths. A separate shelter for explo-sives or inflammable goods may also be needed and itslocation will depend on local port regulations.Altogether, a 200-metre-wide strip is the minimumusually needed to provide adequate space for all essen-tial facilities-cargo-handling facilities, transit storage,delivery and receiving areas and ancillary services. Theoffices in the vicinity of the operating area should beused only for the personnel needed for daily routineoperations.

0. Layout for coastal or island berth

81. A layout suggested by the UNCTAD secretar-iat for a small berth for coastal trade or as the generalcargo facility for a small island is shown in figure 12.The features to be noted here are the ro/ro ramp andthe clear road access to it. Substantial covered storagearea is often needed at such berths since they may alsobe required to assume a limited warehousing role inview of the absence of users’ depots in the local area.

P. Manpower planning

82. The principles governing the organization andplanning of the use of labour are discussed in the IL0publication (A.A. Evans, Technical and SocialChanges in the World’s Ports) mentioned in section B ofthe reference list given in annex II. That publicationplaces the emphasis on the social aspects of changingmethods of cargo handling, since these are the con-straints which usually limit the port management’s free-dom of action.

83. Purely from a quantitative point of view, thereis the requirement for the planner to specify the size ofthe cargo-handling labour force needed to operate aport. It is necessary, as with berthing-points and stor-age, to plan the size of the labour force separately foreach berth group or zone, since there are not likely tobe significant economies of scale extending beyond theboundaries of a port zone and, furthermore, productiv-ity and labour motivation should be improved througha reasonable degree of specialization.

84. The composition or strength of a gang will be

the subject of negotiation between the parties and theoutcome will be arrived at by agreement. It is difficultto lay down what the minimum size of a gang should befor different types of cargo, and there is room formarked differences of opinion. There is, therefore, agreat deal to be said in favour of not fixing gangstrengths too rigidly in advance, but allowing them tobe adapted to meet real needs. The first step is to de-cide the approximate labour requirements for the berthgroup and to plan in terms of number of gangs ratherthan in terms of manpower. The appropriate gang-poolsize for each shift for the berth group may be calculatedapproximately as follows:

Gang-pool size per shift = Average number of gangs per shipper shift t imes the number ofberths in the zone

Thus the total gang-pool size for the zone will be thegang-pool size per shift times the number of shifts perday.

85. However, this rough rule takes no account ofthe need, when all berths are occupied, to provide extralabour for peaks of demand caused by the simultaneousstarting of work on a group of ships or by the need forintensive working on a number of vessels. Where thereare more than six berths in a group sharing the samelabour pool, no significant allowance need be made,but for smaller numbers of berths a reserve capacity ofextra gangs above the number given by the approxi-mate calculation may be needed. A shortage of gangsduring periods of peak demand can have a direct effecton ship turn-round time. For typical traffic streams andberth occupancies, a simulation technique has beenused to quantify this relationship.

86. Figure 13 shows, for two, four or six berths inthe group, the increase in waiting time caused by vari-ous levels of gang-pool size expressed as the ratio of thenumber of gangs available to the gang-pool size givenby the approximate calculation mentioned above. Theeffective gang-pool size is defined as the average num-ber of gangs that are available to work at the terminalduring a shift. Thus the number of gangs in the pool forone shift must be increased by a factor to take accountof holidays and illness. A typical factor is 1.3. The aver-age number of gangs per ship per shift is one of theelements used in planning chart I. As figure 13 shows,as the number of berths increases, the demand issmoothed, and the benefits of a ratio greater than 1.0are reduced.

87. For example, a two-berth port, with an effec-tive gang-pool size of four gangs and utilizing an aver-age of two gangs per ship per shift, would have a ratioof 1.0. Therefore the ship time at port for this case,determined from planning chart II, would have to beincreased by a factor of 1.2 which is obtained fromfigure 13. This increase in time is caused by shortages ofgangs during peak periods. The waiting-time correctionfactor can be used in cost-benefit analyses to assistmanagement in deciding how large the gang poolshould be. In the above example, increasing the effec-tive gang-pool size to five gangs would give a ratio of1.2 and reduce the correction factor to 1.1. The 10 percent reduction in ship turn-round time would have to becompared with the cost of increasing the gang-poolsize. This analysis would assist management to deter-

136

Small modern coastal or island berth

P a r k i n g .,.]I II t

I--L--------L-i---i

I

iDelivery area

t

rRO/RORAMP

Gang-pool size correction factor for break-bulk general cargoterminal planning

mine the best gang-pool size.

Q. Quayside rail track

88. Although the volume of cargo for direct dis-charging to and loading from rail will be the governingfactor, there is a strong case in general against quaysidedirect delivery to rail for break-bulk operations,Quayside wagon-shunting operations are very difficultto organize in such a way that high productivity can beachieved at the hatch being worked without interfer-ence with gangs working other hatches or other ships,Where possible, the loading to rail for onward trans-port in the case of imports, and the sorting of consign-ments from up-country for export, should be carriedout in a rail yard away from the quay, with transferfrom and to the quay being carried out on port mobileequipment. normally trailers. This move away fromdirect delivery to and from rail transport is due to thedeclining volumes of packaged bulk shipments beingcarried on general cargo liners. Only where a con-tinuing and large volume of cargo in the form of heavymachinery, iron or steel and large bundles is foreseen,would the provision of quayside rail track be justified.

R. Quay cranes

89. With the exception of those ports where there isa large tidal range, the use of quay cranes usually offerslittle handling advantage over the use of ship’s gearwhile entailing heavy capital expenditure and ad-ditional maintenance problems. The difference in pro-ductivity between quay cranes and ship’s derricks hasgenerally been due to the difficulty of working derricksdirect to rail wagons without frequent shunting. If thereis no question of direct working to rail wagons, thedifference in productivity becomes insignificant. Theadvent of shipboard electric cranes further sways theargument. The strengthening of the quay edge necess-ary for quay cranes, and the installation of the requi-site crane track and electrical equipment involvefurther expenses which should be avoided wherepossible.

90. It may be necessary for port management toaccept the idea that the tradltional forest of crane mastsis no longer the right picture of a break-bulk berthgroup. A clear, well-surfaced apron for speedy transferoperations is a more appropriate picture. Only in thecase where a continuing and large volume of heavy liftsis forecast are rail-mounted quay cranes justified.

91. If conventional rail-mounted quay cranes arenot to be provided, a small number of mobile cranes onpneumatic tyres will be needed to lift the heavy items,including containers carried on deck, that will inevit-ably arrive. Normally, these special cranes will beneeded for only a fraction of the ship working time andthe number required is small, normally one per berth orone for two berths. When not required, they can sup-plement the mobile cranes working in open storageareas. These heavy mobile cranes with high towers forship working are at least as expensive as conventionalquay cranes, but they are much more flexible. A typicalcrane is shown in figure 14.

FIGURE 14

Mobile dockside tower crane

S. Provision of mobile equipment

92. When traditional handling methods are used inconventional break-bulk operations, the equipmentallocated for the transfer of cargo to and from thequayside is often insufficient to permit the transferoperation to keep up with the hoisting of loads in or outof the ship’s hold. This is demonstrated by the frequentsight of a stationary crane or derrick waiting for a loadto be hooked on or off. Careful equipping and planningof the transfer operation will thus often be the mosteffective single method of raising ship-handling produc-tivity.

93. It is difficult to give clear economic justificationfor any specific level of equipment for the quaysideoperation, as can be done for the provision of berthsand sheds; the estimate of equipment needs must bebased on experience of the type of operation proposed.When the equipment needs have been estimated theymust be included, together with the estimates for re-serve equipment, spare parts and maintenance services,as an integral part of the investment proposal. Noattempt should be made to economize in this area,since without proper equipment the economic andfinancial success of the whole investment will bejeopardized.

94. In recent years the quantity of mechanicalhandling equipment needed per berth has increasedowing to the greater variety of cargo classes, including ahigher proportion of palletized cargoes, and increasingnumbers of containers and heavy loads carried on vir-tually every route, together with a continuation of thetraditional break-bulk cargo. Moreover, higher equip-ment requirements than seem appropriate at first sightmust be provided to allow for the time equipment is outof service because of scheduled maintenance, break-downs and repairs.

95. As described in part one, chapter I, the projectplan for a new development should include an opera-tional plan. This plan should describe how ships are to

138

be discharged and loaded. and goods are to he transfer-red to and from the ship’s side. and how they are to bestacked in the sheds and open storage areas. The equip-ping and layout of the facilities should be based on thisoperational plan.

96. Nevertheless, it is otten difficult at the time ofplanning a break-bulk berth to estimate precisely whatthe proportions of the different traffic will be. In thiscase a standard equippmg pohcy can he adopted alongthe lines set forth below.

97. The types of equipment needed for each part ofthe operation are as follows:

(n) Discharging and loadmg;Where ship’s gear is appropriate: nil;For containers and heavy lifts: mobile tower

crane at ship’s side.

(h) Transfer between quay and storage areas:Fork-lift truck

0,Tractor/trailer combination.

The tractor/trailer combinations can be used in manyways, according to the transfer distance and how longthe tractor would be immobilized either at the ship’sside or at the stack if it remained coupled to the trailer.In principle. as suggested in the repor t of theUNCTAD secretariat on berth throughput’. the tractorshould be uncoupled at both ends of the journey, work-ing with three sets of trailers (one being loaded, onebe& unloaded and one being towjed). This is oftendifficult to do and. since the best method of transfermay be to tow either a single trailer or a train of two orthree trailers, exact planning is difficult. An overallaverage for working methods would be in the region oftwo tractors and eight trailers per gang.

(cl

9 8

Stacking and sorting in shed or open areas. anddelivery from these areas:Fork-lift truck

01Mobile yard crane.

It is unlikely that equipping decisions will beneeded for a single berth in isolation, since to providefor all possibilities will then be very costly. It is prefer-able to plan the equipping of groups of berths-say,three at a time-with a daily allocation of the three-berth pool of equipment as required. For the three-berth group shown in figure 11, the following would bea suitable scale of equipment for allocation among tengangs:

(a) For four gangs working ship’s derricks to fork-lifttrucks:

12 fork-lift trucks:

tra%rs~ f g g’or our an s working ship’s derricks to tractor/

8 tractors;32 trailers;

(c) For two gangs working mobile cranes to tractor/trailers:

’ See Berth Th,oqhpui Syrenmc Mcrhods.foor imp~‘ovrn&’ Grner-al Cargo Opei-mom (Umted Nations puhhcarion. Sales No.E.74.11.D.l). part one. chap IV.

2 mobile tower cranes:4 tractors;

16 trailers:

(d) For transit shed and open storage area opera-tion:

8 fork lift trucks;4 mobile yard cranes.

YY, The three-berth equipment should then beboosted by a reserve for breakdowns and preventivemaintenance, as follows:

M o b i l e cranes 20 pei cent(hut it ~~111 olten hr neceuaq

to prowdc one spare craneII, anv case)

Fork-Iill t r u c k s 25 per ceniT r a c t o r s ,. ‘II p e r centTrailers i per cent

This gives a total three-berth equipment of:

2&ton mobllr tower crilnes 3IO-ton mobile yard cranes SFork-hfl trucks 2sTractors ., ., 15T r a i l e r s 50

100. This level of equipping can be scaled up ordown according to the number of gangs in the opera-tion plan for the port zone. In the absence of localoperational statistics, the following number of gangsmay be assumed for planning purposes:

D e e p - s e a s h i p s 3 gangs. occasionally 4 ( a v e r a g e 3%)

Smaller coastal andshort-sea ships 1 or 2 g a n g s ( a v e r a g e I’/?)

T. Cargo-handling i;achmentsc .d\c

101. The correct range of cargo-handling attach-ments cannot be exactly specified until the detailedcomposition of the traffic is known. In order to makefunds available for their purchase, during and aftercommissioning of the new facilities. a definite provisionshould be made in the project budget. If this is not donethere can be delays in obtaining authorization for minorpurchases that can seriously endanger the operation ofthe new facilities.

102. A few of the attachments which may be re-quired for fork-lift operations are illustrated in figure15. Mobile cranes will also need a range of hook gear,including container spreaders as well as standard steve-dore’s gear. A suitable provision to include in the pro-ject budget is a figure related to the number of cranesand fork-lift trucks provided in the following manner:

E<,Ulp,WliM o b i l e tower c r a n eH e a v y forh-lift t r u c kLight fork-lift truck

U. Elevators and conveyors

103. There are certain limited roles for elevatorsand conveyors in break-bulk operations. Pocket eleva-

139

FI G U R E 15

Examples of fork-lift truck attachments

Drum clamp

tors can be used to work in and out of ship’s holds forlarge consignments. They consist essentially of two con-tinuous strands of chain which carry a continuous can-vas band arranged in loop pockets. Although theoretic-ally such elevators working continuously can producesubstantial outputs, in practice there are frequent inter-ruptions and in general terms it is unlikely that a pocketelevator can reach the speed of a well-planned conven-tional lift-off operation.

104. Various types of conveyor, such as slat, roller,

Port attachmenti,

belt and plate‘eonveyors, can be used wherever thephysical dimensions of the ship and quay permit, forexample in the side ports of side-loading ships. Theymay also be used in transport sheds and warehouses.All conveyors, however, form a barrier to other move-ments and therefore conveyors made up of portablesections are to be preferred to fixed ones when used onthe quay apron. Although conveyors are ideal for hori-zontal transport, they are not cheap, and the scale,speed and flexibility of the operation should be care-fully assessed before installing a large conveyor system.

140

Chapter III

CONTAINER TERMINALS

A. Container ship development

105. Container ships are generally classified into“generations”, that is, as having characteristics typicalof certain stages in container development and con-tainer shipbuildmg. The main characteristics of each“generation” are shown in table 1. The term TEU(twenty-foot equivalent unit or equivalent m goods to acontainer of 20 feet) is a useful standard term for defin-ing the carrying capacity of a container vessel: a 4O-footcontainer therefore counts as two TEUs. The principaldimensions of 20-foot and 40.foot steel containers aregiven in table 2. The R-foot high 20-foot container hasbeen largely replaced by the X-foot 6-inch unit. and forthe 40-foot container the trend is towards units of 9 feetto 9 feet 6 inches.

TABLE 1

Physical characteristics of container ships

“Fl~St-g3l~KGlOIl“contamer ships 750 14 000 180 2 5 9.0

“Second generanon”container ships 1 500 30 000 2 2 5 2 9 11.5

“Third generation”container ships 2 50& 4 o w o 2 7 5 3 2 1 2 . 5

3 000

106. To keep operating costs to a minimum, themaximum utilization of these large modern vesselsmust be achieved. Thus there has been a move to re-duce the number of ports of call of the mother ships andto introduce feeder vessel services to the ports withsmaller volumes of trade. The feeder ships have thetask of rehevmg the long-haul container ships frommaking the extra calls which greatly increase the totaltime they spend in ports. Feeder ships vary in size fromcapacities of 50 to 75 TEUs up to 300 TEUs.

107. The rapid spread of container operations hasbeen very fully documented. A detailed discussion ofcontainerization and its impact on ports in developingcountries is given in the UNCTAD publication on thesubject” and in a series of reports prepared by the UN-CTAD secretariat on the subject of technologicalchange in shipping and Its effects on ports.’ The lastmajor trade routes between highly industrialized coun-tries have been containerized. At the same time, thereis an increasing trend towards containerization of cer-tain specific services linking developing and developedcountries.

’ Unmzorion of Cargo (United Nations publication. Sales No.E.71.11.D.2).

’ “Technological change m shlppmg and ifs effects on ports” (TD!B!C 41129 and Supp.l-6).

TABLE 2

Principal dimensions of typical steel containers

Door opening (fn millrmerres)Width 2 340 2 3 4 0 2 340 2 3 4 0 2 340 2 340Height 2 280 2 2802 137 2 137 2 280 2 260

Inslde cubic capacity(in cuhlc meires) 31.5 30.8 33.2 32.9 67.7 67.0

Tare wqht(m kilograms) 4 050 4 loo2 330 2 260 2 300 2 330

Stacking capmry 9 99 high 9 high 9 high 9 high high high

143

108. Examples of this trend are services betweenEurope and the Caribbean, between Europe and theMiddle East, between Europe and West Africa, be-tween Europe and the Far East, between Europe andSouth America, between North America and the FarEast, between North America and South America andbetween North America and Central America. Gener-ally the vessels involved are of the first generation or,on the shorter runs, feeder vessels. The basic problemswith these services are the imbalance of trade and thelabour problems caused by the reduced damage formanpower.

109. At present these and similar container servicescarry a fraction of the general cargo liner traffic be-tween developed and developing countries, but in de-veloped countries’ ports container services alreadyhandle between 70 and 80 per cent of the cargo. There-fore port authorities in developing countries must con-sider the development towards containerization of theircountries’ trade, and the profound changes in portplanning, management and operations which such de-velopment brings with it. Thus it is not a question ofwhether or not to containerize, but rather when to con-tainerize.

110. Both the break-bulk berth group and the mul-ti-purpose terminal must be capable of handling con-tainers-even if, in the former case, only a small num-ber of units are carried (mainly on deck) in a lineroperation. This chapter is concerned with the special-ized container terminal needed to handle the cellularcontainer ships.

111. These large ships will not normally call at aport without a specialized container terminal offering aspecified level of service. By investing in a specializedterminal a port can make calls by container ships poss-ible, but such an investment cannot be financially justi-fied until a satisfactory level of use is guaranteed. Thecontainer throughput must be around 50,000 TEUs peryear if the investment is to be justified. Below thislevel, the port should either provide limited facilitiesfor container feeder ships or adopt the transitionalmulti-purpose terminal described in the next chapter.

B. Planning and organization

112. It is wrong to imagine that the planning,organization and running of a container terminal is astraightforward task. Figure 16 gives an indication ofthe main factors which have to be taken into considera-tion in planning a container terminal and can be used asa checklist in order to ensure that none of the mostimportant issues have been overlooked. The complex-ity of this type of terminal coupled with its newnessnecessitates a comprehensive training programme ofthe senior operating staff, often in a well-organized andefficient container terminal.

C. Productivity

113. There has been considerable inaccuracy inpredicting container terminal productivity. In thecourse of its investigations into technological change in

shipping and its effects on ports. the UNCTAD secre-tariat found that the average throughput for a sample of21 ports was 442 containers per 24 hours in port,“ afigure significantly below figures which are oftenquoted.

114. The average productivity per hour per vessel,even averaged over a long period, varies considerablyfrom one terminal to another. from about 10 to 50containers per hour, even on the same cellular shipoperated by two gantries, averaged over a 24-hourperiod. This figure refers to single units either loadedor discharged and includes any idle time within a work-ing period. The early operating objective of lifting onecontainer off and one container on in a combined cycleis now rarely achieved or even attempted for any sig-nificant period.

115. The gross productivity per hour can be con-verted to a daily figure by using the ratio of workingtime to berth time. The working time includes any idletime within a working period, such as that due to equip-ment breakdown, and therefore for ports operatingaround the clock the ratio could be 100 per cent. Anumber of reasons prevent ports from achieving this24-hour per day operation, however, and the ratiosusually vary between a peak of 95 per cent and a low of40 per cent. Clearly this variation in the intensity ofworking can have a significant effect on the annualthroughput of the terminal.

116. The figures for throughput per 24 hours in thesample referred to above varied from a high of approxi-mately 750 containers to a low of approximately 225containers. The average throughput for these terminalswas nearly 450 containers per 24 hours in port, Giventhat at most terminals 24-hour operation seven days aweek is standard practice, the typical throughput wascalculated as follows in the early 1970s:

Average output per gantry-crane 20 units per hourAverage number of gantry-cranes

allocated to each vessel: 2Working time/berth time ratio: 0.80

Thus, according to this earlier method,

Average throughput = 24 (average output perper 24 hours crane) x (average number of

cranes allocated) x(working time/berth timeratm)

= 24 (20 x 2) (0.80)= about 770 containers.

117. The actual average throughput of the sample isslightly less than 60 per cent of this theoretical figure.Clearly the figures used in this procedure are too opti-mistic for planning purposes and more realistic figuresshould be used when calculating ship turn-round timefor the economic analysis, especially when one consid-ers that this sample is for major terminals handlingsecond- and third-generation cellular vessels and work-ing three shifts with two cranes on average.

* “Technological change in shipping and its effects on ports: theunpact of unitization on port operations” (TDiBIC.4il29/Supp.l),para. 90.

142

Dependency tree for container terminal planning

PL ANNING

/

/

118. There is little doubt among container terminalexperts that the present performance of container facil-ities throughout the world is far from optimum. Nodoubt part of the difficulty stems from the fact thatthere is excess capacity at the present time of economicslump and that fewer goods are being moved by thisform of transport. However, there are also operationalinefficiencies which are due to inappropriate planningdecisions, operating procedures, equipment or man-power policies. The main reasons lie in the imbalancebetween the capacities of the various system parts at aterminal, which results in low hourly productivity percrane, and inadequacies in the inland transport system,which often results in long non-operational periods.

119. In general, the capacity which has been pro-vided for the loading and unloading of containers ex-ceeds the terminal’s transfer, stacking, storage and de-livery capacity. This has been due primarily to anunderestimation of the transfer distances that wouldhave to be covered and of the proportion of time thatequipment would be out of service for maintenancepurposes. A survey carried out in four ports in theUnited Kingdom showed that the proportion of timeduring which straddle-carriers were out of service formaintenance averaged almost 30 per cent.5 The figurewas even higher than this in ports with a high workload.This fact supports the UNCTAD secretariat’s viewthat, for developing countries, tractors and trailers arelikely to be the most economic system for the transferoperation and that straddle-carriers should be con-sidered as merely one possibility for the stacking oper-ation.

D. Container handling systems

120. The four most commonly used container hand-ling methods in operation today are the trailer storagesystem, the heavy-duty fork-lift truck system, the strad-dle-carrier system, and the gantry-crane system, thegantry-cranes being either rail mounted or rubbertyred. There can also be various combinations of thesetypes of equipment at individual terminals. The essen-tial features of each of the main systems are given in thefollowing paragraphs.

1. TRAILERSTORAGESYSTEM

121. The import containers discharged from a shipby crane are placed on a road trailer, which is towed toan assigned position in the storage area where it re-mains until collected by a road tractor. Trailers carryingcontainers for export are placed in the storage area bythe road tractors and towed to the ship by port equip-ment. The containers are thus of necessity stored onehigh. requiring a large transit storage area (see figure17). Limited soil improvement is required due to lowloading. This is a very efficient system because everycontainer is immediately available for removal by a

’ H. K. Dally, ‘Straddle carrier and container crane evaluation".Nalionnl Ports Councd Bdletin (London), No. 3, 1972.

tractor unit, but in addition to requiring a large area italso requires thousands of trailers, entailing consider-able expense. This method is therefore normally usedonly when a shipping company provides the trailers andeither operates at a leased or reserved berth or hasaccess to a special trailer compound. This makes trailerstorage generally unsuited for use by multi-user termin-als. As a rough rule of thumb for 2,000 TEUs, a con-tainer storage area of 100,000 square metres is re-quired.

2. FORK-LIFTTRUCKSYSTEM

122. A heavy-duty fork-lift truck with a capacity of42 tons and a top-lift spreader is capable of stackingfully loaded 40-foot containers two or three high, withthe most common stacking height of two high. A sidespreader can be used for 20-foot containers, both fulland empty, and for 40-foot empties. Empty containerscan be stacked four high. This system places heavyloading on the surface of the terminal and adequate soilimprovement and surfacing must therefore be pro-vided. Most port authorities and cargo-handling com-panies have experience in both the operation andmaintenance of fork-lift trucks. Such trucks can trans-fer containers from the ship’s side to the stacking area,or tractor-trailer units can be used which will reduce thenumber of fork-lift trucks required. Typical aisle widthsin the stacking area are 18 metres for 40-foot units and12 metres for 20-foot units. As a rough rule of thumbfor 2,000 TEUs, with an average stacking height of 1.5boxes, a container storage area of 72,000 square metreswould be required.

3. STRADDLE-CARRIER SYSTEM

123. At the present time the straddle-carrier systemis the predominant one. Straddle-carriers can stackcontainers two or three high, move them between quaycrane and storage area, and load or unload them to orfrom road transport (see figure 18). In the past, how-ever, these machines have had a poor reliability record.poor visibility, high maintenance costs and a short life.Leaks from joints in the hydraulic system and oil spil-lage from damaged pipework caused highly slipperysurfaces, broke up asphalt paving and necessitated con-tinual renewal of the white lines and numbers essentialin stacking areas. Safe operation demanded that strad-dle-carriers should operate within a restricted area, andthat workers on foot should be kept out of the workingarea. The fact that despite these drawbacks the strad-dle-carrier is so widely used is a testimony to its flexib-ility and its ability to meet peak requirements. Fur-thermore, major improvements have been made in thedesign of straddle-carriers, and most of their poormaintenance record resulted from a lack of preventivemaintenance and the excessive use of the equipment fortransfer operations. A variant of this system is the useof tractor-trailer units for the transfers betweenquayside and storage area, and the use of straddle-carriers only within the storage area for stacking andselecting containers. Approximately six straddle-carriers are required for each ship-to-shore gantry-

144

FIGURE 17

Example of trailer storage container terminal layout

FIGURE 18

Example of straddle-carrier container terminal layout

Conramer rerminrrl, Bremerhaven (Federa l Republ ic of Germany)

crane. As a rough rule of thumb for 2,000 TEUs, acontainer storage area of 40,000 square metres for 1.5-high stacking, or 30,000 square metres for two-highstacking is required.

4. GANTRY-CRANESYSTEM

124. In this system, containers in the storage areaare stacked by rail-mounted or rubber-tyred gantry-cranes (see figure 19). Rail cranes can stack containersup to five high (although normally containers arestacked no more than four high). Rubber-tyred gantry-cranes can normally stack containers two to three high.Tractor-trailer units make the transfers betweenquayside and storage area. This system is economical inland because of the high stacking, and is suitable forvarying degrees of automation. Gantry-cranes have agood safety record, are reliable and have low main-tenance costs and a long life in comparison with strad-dle-carriers. They are far less flexible but to offset this,gantry-cranes (particularly the rail-mounted type) arebetter suited for automation. In the longer term, theneed to economize in land is likely to be very impor-tant, and this favours the use of gantry-cranes. Thissystem is especially useful where exports are a substan-tial proportion of the total traffic, but perhaps less thanoptimum where import cargoes constitute the majorportion of the traffic. This is because import containersneed to be retrieved in a random fashion and, withhigh-stacking freight, many units need to be shifted. Asa rough rule of thumb for 2.000 TEUs, a containerstorage area of 16,000 square metres is required for3.5-high stacking.

5. MIXEDSYSTEMS

125. Mixed systems employ the best equipment forthe particular operation. However, for such systems tobe successful, a comprehensive information system andrigid operating policies are required, together with ex-cellent management. For example, straddle-carriers areused for extracting individual import containers anddelivering them to road vehicles, but gantry-cranes areused in the container park for feeding exports to theship where it is possible to work straight off an exportstack. Another mixed system is one using straddle-carriers for stacking full containers and fork-lift trucksfor empty containers.

E. Area requirements

126. The choice of operating methods and equip-ment, and thus the area of land needed for a containerterminal, depends to a high degree on the availability oflocal land and on soil conditions. If the terminal is lo-cated far from urban agglomerations and land is plenti-ful and inexpensive, a system of storing containers onlyone high may be the most economical. For this layout,no costly equipment is needed for stacking containersbut transfer distances may become long, resulting inadditional transfer equipment being needed. Also, onreclaimed land with relatively soft soil, this one-highmethod is particularly advantageous since the carryingcapacity of the soil does not need to be reinforced as itwould for heavy stacking equipment. On the otherhand, if land is scarce and expensive, the stacking ofcontainers as high as physical conditions and commer-cial requirements allow becomes a necessity

FIGURE 19Example of gantry-crane container lerminal layout

146

127. Lack of container s torage space has beenanother serious constraint on operations. It is true that,since the introduction of containerization on the majortrade routes, there is a trend towards larger storageareas for container terminals. but in many. planneddevelopments the space requirements are stdl under-estimated. Sufficient operational area must be left forinterchange areas for both ship-to-shore and stack-to-inland operations, as well as for vehicle parking,maintenance, workshops and administrative buildings.

128. The most frequent error has been to assumethat the maximum stacking height can always beattained. In practice the average stacking height ismuch lower, depending on the amount of shifting ofcontainers necessary in the storage area. and the needfor containers to be segregated by destination, weightclass. direction of travel (inward or outward). some-times by type and often by shipping line or service. Theneed for storage of empty units and of unserviceablecontainers has also often been overlooked.

129. A further serious mistake is the belief thatcontainers have a shorter terminal transit time thanbreak-bulk cargo. In fact, the same constraints whichcause break-bulk cargo to stay in the port will oftenhave a similar effect on container cargo. In practice it isnot unusual to find that the transit times for both arevery similar. The following are typical delay times forcontainers at container terminals taken from a numberof terminals:

Containers carrying import cargo 7Conrainers carrymg e x p o r t c a r g o 5Empty containers .., ,.. .., 20

130. Planning charts similar to those whose use isexplained in section G of chapter II, “The break-bulkberth group”, are also helpful in container terminalplanning.

131. When sufficient space is set aside for the con-tainer park, container freight station (CFS), marshall-ing and other administrative areas for a terminal oper-ating adjacent to the quay, then there are bound to beenough berths for the traffic. For this reason, the ter-minal area requirements are calculated first, and thenthe number of berths checked to see if there is enoughberthing capacity.

132. Container terminal, planning chart I (see fig-ure 20) is used to determine the most importantdimension of a container terminal, the container parkarea. The figure for the number of TEUs to be handledacross the quay per year is entered on the planningchart. The planner descends vertically to the turning-point where the vertical line meets the line representingthe average time the container spends in transit at theterminal. He then moves horizontally to the left to thenext turning-point defined by this horizontal and theappropriate line for the area requirement per TEU.

133. The area requirement per TEU depends onthe type of container-handling equipment used and theconsequent access requirements and maximum stackingheight. Typical area requirements are as follows:

7

3

234

134. The planner then descends again to the ratioof the average to the maximum stacking height of con-tainers. The average height is the level at which opera-tionally the container park area is consldered full. Forexample. although a straddle-carrier can stack contain-ers three high, it would not be practical for the operatorto stack the entire park three high as it would then beimpossible to remove individual containers. An adjust-ment factor must therefore be applied to allow for thisfact. The planner now moves horizontally to the rightto the reserve capacity safety factor-the factor whichallows the park to handle peaks in demand.

135. Finally he moves upwards to the containerpark area required. The intersections of the trajectoryand the axes give the planner the following informa-tion: holding capacity required, in TEUs; net transitstorage area requirements; gross transit storage arearequirements; and container park area. The chart maybe used repeatedly to determine the effect on area re-quirements of different handling equipment in order tofind the most economical solution for local conditions.

136. The planner must now estimate the area re-quirements for the CFS, the structure used for “stuf-fing” and “stripping” containers and for con‘solidatingand sorting consignments in the port area. Assumingthat each TEU container handled via the CFS requires29 cubic metres of space, the CFS storage area can bedetermined by using planning chart II (see figure 21).The following turning-points are used: average transittime of consignment; average stacking height m CFS;access factor to allow for circulation and operationalareas in the CFS; and reserve capacity safety factor forperiods of peak demand. For example, a terminal atwhich 20,000 TEUs per year pass through the portCFS, with a mean transit time of 10 days. a stackingheight of 2 metres, an access factor of 0.4 and a safetyfactor of 25 per cent, would require a CFS storage areaof 14,500 square metresh. The structure should alsohave a large roof overhang to allow protection of thecontainer loading bays from the weather (see figure22).

’ Thlh figure can be compared wth other CFS areas at the follow-mg container terminals: Guam: 2 berths. CFS 3.066 m’-: Keelung. 5berths, CFS 2,700 m’: Port Kelang. 2 berths. CFS 6,771 m2; Singa-pore. East Lagoon, 3 berths. CFS 21.000 m’: KWI Chung berth 4. 3berths, CFS 23.241 m2

147

FIGURE 20

Container terminal, planning chart I: container park area

0055

A

/J’/ ,I,‘/ /,,A,’ /

/’ 1’

149

FIGURE 22Cross-section of container freight station

137. As previously mentioned, in addition to thecontainer park and CFS areas, the terminal requiresspace for marshalling areas, vehicle parking, rail androad access, customs, damaged containers, reefer car-goes, staff, administration, maintenance and dangerousgoods storage facilities. Typical additional require-ments per berth could be from 20,000 to 30,000 squaremetres.

F. Berth occupancy at specialized unit terminals

138. Specialized berths such as container terminalscan achieve cargo-handling rates five or even ten timeshigher than conventional berths. In addition, unitiza-tion results in a considerable reduction in the numberof calls through the pooling of services, with larger con-signments per vessel, which further increases the pro-ductivity per call. Thus, in unitized form, a given quan-tity of cargo can be handled at fewer berths, and it willbe rare that a container terminal investment decisionwill involve more than two berths in the initial phase.Therefore the berth occupancies which will be appro-priate in order to keep waiting time to an acceptablelevel will be low. The fact that container ships are muchmore expensive than general cargo vessels reinforcesthis need to minimize waiting time. In the planningprocedure given below, the basic economic effect ofwaiting time will be a main factor in the investmentdecision, but there will in addition be the need to con-sider other criteria.

139. In the case of any special-purpose or advancedtype of installation, the following three criteria shouldnormally be considered:

(a) Whether the resulting berth occupancy will givethe right balance between ships waiting for a berth andberths waiting for a ship;

(6) Whether the average ship turn-round time willsatisfy the normal user, irrespective of what this implieswith regard to berth utilization;

(c) Whether there is sufficient peak capacity to givea satisfactory individual service to the exceptional,more demanding, user and to ensure generally againstcongestion during periods of exceptional traffic.

140. Performance calculations should be carriedout to demonstrate that all three of these criteria aresatisfied. There will often be a difference in the capaci-ties which will satisfy the different criteria, and it will be

necessary to reach a compromise. In reaching this com-promise the port management will often need to takean entrepreneurial decision: there may be no clear cutsingle solution with an economic justification which atthe same time gives a level of service that will satisfycustomers. It will be for the decision authority to con-sider these investment risks, and in order that it may dothis the planning team should present separate propos-als, according to each of the three criteria, for purposesof comparison. These will be more useful to the deci-sion authority than a single proposal that attempts tomeet all three criteria.

141. The container terminal planning chart III (seefigure 23) is utilized to determine the berth-day re-quirement. The method used is similar to that used forthe previous charts, starting with the standard workinghours per day that ships will be worked when at theterminal, and with the following turning-points: aver-age number of units per hour per crane, which shouldinclude an allowance for equipment down-time; num-ber of cranes used per ship (gantry-crane effectivenessfactor per crane = 1 crane : 1; 2 cranes: 0.9; 3 cranes:0.8); average number of moves per ship; and number ofships per year. This path gives the average number ofunits per day per berth, the average number of unitsper day per crane, the average berth time per ship(which includes a one-hour period for berthing and de-berthing the ship) and the annual berth-day require-ment.

142. As we are now considering the performance ofthe terminal, note that we are using units (i.e. numberof containers) rather than TEUs (i.e. twenty-footequivalent units). When the containers to be worked toand from a ship are estimated in TEUs, this figure mustthen be converted into units by estimating the propor-tion of 40-foot units among the total number of units.The number of moves for discharging and reloadinghatch covers should also be included.

143. Starting with the berth-day requirement, thefollowing turning-points should be used in planningchart IV (figure 24): number of berths; commissiondays per year; number of berths; and average daily shipcost. The path traced gives the total time at port andthe annual ship cost. Operators of expensive containerships may wish to know, in addition to the average shiptime in port, the probability of a ship having to waitbefore agreeing to use the terminal. For this reason,additional scales are given on the lower left of the chartwhich show, for one, two or three berths, the probab-

150

-- .__

I

Container terminal, planning chart 111: berth-day requirement

800 700 600 500 400 300 2 0 0 1 0 0I I I I I I , I I I , , ANNUAL BERTH DAY REQUIREMENT

N U M B E R O F UNITS PER DAY P E R B E R T H I- I 1 , 1 , 1 , 1 , /1 0 0 200 3 0 0 400 5 0 0 6 0 0 7 0 0

FIGURE 24

Container terminal, planning chart IV: ship cost

ANNUAL BERTH-DAY REOWREMENT100 200 300 400 500

1 I600 704

I I, I , , , , , I,

F 400

\\\ +mo / / 7

ru.I.Y,.L an,r c”a,.4.3

,I,.2 .1

I0 0

L I I1 I I I , , , , ,10

1I I

,.”I I I, ,I,,,,,,,

ility of a ship having to spend one or more averageservice times queueing for a berth. For example, if theaverage time at berth is 12 hours, then the probabilityshown is the chance of a ship having to wait 12 hours ormore for a vacant berth. The probabilities are given asa fraction; thusO.10 equals a 10 per cent chance. To usethese probability scales, draw a line horizontally to theleft from the “number of berths” turning-point.

144. The relationship between berth utilization andtotal time at port is based on queueing theory. Theassumption has been used that the service time and theinter-arrival time follow an Erlang 2 distribution. Amore detailed discussion is given in annex II, section D.For a terminal servicing a near-sea route for one or twooperators, the arrivals would be more regular and theberth waiting time for a given berth utilization would beless. However, these curves can be used with a highdegree of confidence for most container terminals.

G. Information systems

145. Many terminal operators have decided to util-ize an electronic data processing system to assist in thecollection and processing of the required information.It is generally accepted that for terminals handling100,000 or more containers a year, a manual system,which may have proved very satisfactory up to thatpoint, becomes far less practicable. A computer systemcan be introduced to handle the large quantity of infor-mation. There are, however, cases where efficientmanual systems have been successfully used for muchlarger throughputs.

146. At present, many container terminals haveboth a manual and a computerized system, but each hasa specific function. The manual system serves mainly toassist the terminal operator in the control of all ter-minal operations (including the location of the contain-ers at the terminal). The computer-assisted system, onthe other hand, is used to process invoices, gatherstatistical data and to present the container operatorswith detailed information, for example, on the type andnumber of units at the terminal, the availability of emp-ty units and productivity rates on the ship. The projectproposal for a container terminal should include anysuch data processing equipment as a terminal equip-ment cost item.

H. Schedule-day agreements

147. The need to achieve a reasonable level ofberth occupancy without increasing the probability ofships having to wait has raised the question of thescheduling of arrivals. If vessel arrivals can be sche-duled, a much higher berth utilization is possible with-out significant waiting. It may be possible for agree-ments to be concluded between container terminaloperators and shipping lines for specified schedule-days, particularly with short-sea services. Ships thatarrive in the scheduled slot are then guaranteedimmediate berthing.

148. Unfortunately. the risk that vessels will beslowed down on deep-sea routes, for example byweather, means that large safety margins normally haveto be provided. These destroy much of the advantage ofthe scheduling, and experience has shown that the shipsfrom several lines arriving at a deep-sea container ter-minal are only slightly more sy,stematic m their arrivalpatterns than the traditional lmers they replace, Thearrival pattern at a terminal is also affected by the hoursof work at other ports. For example, if other terminalsin the area do not work at the weekend, one that does islikely to find a group of vessels arriving at the end ofthe week.

149. Faced with this situation, the best that a largecontainer terminal operator may be able to do is to givethe fastest turn-round service possible on a first-comefirst-served basis. The use of a buffer stack of cargo tospeed up service is a possibility. There could. for exam-ple, be a “post-stack” for import cargoes and a “pre-stack” for export cargoes, the stacks being placeddirectly on the quay near the vessel.

I. Container feeder services

150. The trend towards concentrating traffic at asmall number of pivot or gateway ports is particularlypronounced on the long-distance container routes. Thespecialized container vessels have become larger andmore sophisticated, while the cost of building a moderncontainer terminal is very high. The economics aremore and more in favour of unloading and loading allcontainers at one well-equipped port, and distributingthem by coastal feeder vessels to other ports in theregion.

151. It is difficult to forecast such developments,and close discussion is needed between the planner andthe shipping lines concerned. The attitude of shippinglines is liable to change, and while they may initiallywish the mother ships to call at every port, at a laterdate they may wish to introduce feeder services. Ship-pers prefer direct calls as this reduces both transporttime and the chance of damage to goods.

152. Feeder ships are normally designed for a speci-fic service, with the characteristics of the port in mind.They are relatively small (usually having between 10and 20 per cent of the capacity of the trunk route ves-sel), and can be built without ship’s gear in order toincrease their carrying capacity, to improve their stabil-ity and to reduce costs. The majority are probably roiroships, but there are also pure cellular feeder ships andcombination roiro and lift-off vessels.

153. The load factor of feeder vessels is normallyvery high, approaching unity. At the ports servicedonly by the feeder vessels. however, handling rates-although much higher than with the traditional break-bulk operation-will be lower than at the pivot or gate-way specialized terminal because only one gantry-cranecan work the feeder vessel. A typical figure of 15 unitsper hour may be achieved for a feeder ship with acapacity of 100 TEUs. Table 3 gives the principal char-acteristics of several ships in this class.

1.53

TABLE 3

Typical container feeder ships

Roll-oniroll-off ,....

Lift-on/lift-off ,, ,.

Roll-on/roll-off ,........, ,...... .,.....Lift-on/lift-off

Roll-on/roll-off ,.........Lift-on/lift-off

4 580 1 7 6 1 3 0 17 6.25 Catamaran design

1 260 1 0 6 7 7 13 3.70 GKldW

6 5 0 0 330 1 1 5 1 9 7.40 Equipped with angled stern rampand one 3%ton gantry-crane

2 080 111 8 7 14 4.70 Equipped with stern rampand one 30-ton gantry-crane

J. Types of container handling equipment

154. The large size of IS0 containers necessitateslarge equipment for handling. The choice of a partic-ular handling method is related to the type of traffic(for example, ship to shore, train to truck or truck toground), the number of containers to be handled perhour and the distance of travel, which depends on thesize and the shape of the site and the number of con-tainers to be stored.

1.55. Ship-to-shore gantry-cranes are specially de-signed for container traffic. They are capable of sub-stantial cantilever lifting, with spreaders mounted onrotating tables so that containers can be aligned straightinto a stack, or on to a vehicle (figure 25). These areexpensive pieces of plant, a 35-ton capacity crane forship-to-shore operation costing approximately $4.5 mil-lion (mid-1981 values), including the rail track. Theplanner must design circulation routes so that any stop-page will not interfere with crane movement. For relia-bility, a terminal will normally require a minimum oftwo ship-to-shore gantry-cranes.

156. Gantry-cranes can also be used in the con-tainer yard, where they combine the mobility of strad-dle-carriers, although slower, with the wide span andheight of the ship-to-shore gantry-crane. The yard gan-try-cranes may be on rubber tyres, which allows them

to move to another task at a different part of the site.The weight of the gantry requires special runways toavoid damage to the terminal surface. Rail-mountedgantries allow wider spans and higher stacking heights.A rubber-tyred gantry crane costs approximately $0.75million and a rail mounted gantry, including rails,about $1.5 million (mid-1981 values).

157. Straddle-carriers are efficient for linear stack-ing operations up to a height of three containers. Whilethese carriers are fast and manoeuvrable, they are ex-pensive to buy and operate, with a typical purchaseprice of $0.5 million (mid-1981 values) for a carriercapable of stacking containers three high. Among thereasons for the high operating costs are maintenancecosts and down-time. Modifications are improving thereliability of this type of equipment.

158. Fork-lift trucks can be used for containerhandling. Operators equip their fork-lift trucks withtop-lift or side-lift spreader beams as well. The use ofthese attachments for container movements by fork-lifttruck removes the risk of damage by forks. Normalfork-lift trucks can be used for the handling and stack-ing of empty containers with fork tunnels, while a spe-cial heavy-duty truck is required for full units. The in-vestment for a 35-ton fork-lift truck, including thespreader, is around $300,000 (mid-1981 values). A 3-ton capacity fork-lift truck would cost approximately$30,000 and a lo-ton capacity truck $100,000.

FWJRE 25

Typical gantry-cranes

A. Ship-loading gantry container crane B. Gantry-crane for stacking and sorting containersand feeding ship-loading cmne

154

Chapter IV

THE MULTI-PURPOSE GENERAL CARGO TERMINAL

A. Economics

159. The sequence of changes in the kind of trafficarriving at ports, as a result of growth and transporteconomics, was discussed in part two. chapter I, “Ter-minal planning considerations”. The need for a multi-purpose terminal to handle both break-bulk cargo anda variety of unit loads during the transitional phase(denoted as phase 4 in part two. figure 1) was pointedout.

160. The role of the multi-purpose terminal is toprovide efficient handling facilities for the period-which may last many years-when general cargo shipscalling at the port may carry a variety of cargoes trans-ported in modern ways: containers, flats. pre-slung car-goes, large units of iron and steel, large units of pack-aged timber, as well as cars and heavy machinery,together, of course, with a basic load of break-bulkcargo, increasingly palletized. These modern methodsof transporting cargoes were introduced in order to re-duce the cost of handling cargoes at ports in developedcountries, and the cost of carriage by sea. However,they can actually cause a decrease in cargo-handlingproductivity and disrupt operations at a port not equip-ped to handle them efficiently.

161. In order to be able to handle all these cargoesefficiently, the terminal needs to have a greater varietyof mechanical equipment than is required for a conven-tional break-bulk terminal, and a different range ofequipment than is normal for a specialized containerterminal. The terminal needs a different layout, andmodern management. These requirements aresummarized below, and are given in more detail in thereports of the UNCTAD secretariat on technologicalchange in shipping and its effects on ports, already re-ferred to several times.’ Although the initial cost of theterminal is high, a high throughput can be achieved inview of the terminal’s flexibility, and furthermore it canbe fully utilized soon after commissioning in view of itssuitability to handle whatever traffic may come. Theresulting cost per ton of cargo handled and the totalinvestment can therefore be significantly lower than thealternative of continuing to build extra conventionalberths.

162. For example, a two-berth multi-purpose ter-minal working two shifts per day and 200 days per yearshould achieve a throughput of some 650,000 tons peryear, assuming a productivity of 800 tons per ship-shiftfor a typical mix of cargoes with a different productivityfor each type of cargo, as follows:

‘TDIBiC.41129 and Supp.l-6

T”,,, pe, lhifr

Conventional general cargo.palletized and pre-slung cargoes ., 450

Packaged forest products andbundled ,mn and steel products I 000

Containers and rolro umts I 500

163. Using 1980 cost figures. the UNCTAD secre-tariat found that such a terminal would cost in the re-gion of $33.3 million and give a handling cost of $20 perton (including the cost of ship’s time in port). If thesame cargo were handled over conventional berths, thethroughput would probably be no higher than about175,000 tons per year, and would thus require four con-ventional berths costing approximately $50 million andgiving an effective handling cost per ton of about $33.The figures given for a multi-purpose terminal, whichimply very significant savings, are based on typical costsand interest rates in developing countries.

164. The multi-purpose terminal offers full utiliza-tion of a high-capacity facility from an early date andoffers the possibility of reducing the total port cost forsome neo-bulk cargoes. In view of the added long-termadvantage that a multi-purpose terminal can more eas-ily be converted later to a specialized unit load ter-minal, there is a strong argument for ports in devel-oping countries to think of general cargo developmentmainly in terms of multi-purpose facilities.

B. Layout

165. Figure 26 shows a proposed layout for such atwo-berth terminal. The following features should benoted: the placing of unit load transit and consolidationsheds at the rear of the quay, so that trucks can beserved alongside the sheds without interfering with thetransfer operations; the substantial open storage areascloser to the quay for any form of unit load, includingcontainers, or for open storage general cargo; the largequay apron operational areas; the areas for road andrail transport through the terminal; provision of a roiroramp.

166. The concept as shown, adapted to local condi-tions, has been applied in a number of new port de-velopments for handling semi-bulk and neo-bulk car-goes, although mostly in developed countries. Thelatest developments in layout are noted and are to bereferred to when studying figure 26.

(a) Extension of berth length to 400 or 450 metres tohandle larger ships and ship-based ramps;

(b) Increase in storage area to handle larger consign-ments and longer cargo transit times resulting in totalterminal area of 120,000 square metres versus anoriginal area of 100,800 square metres;

155

FIGURE 26

Proposed layout for a two-berth multi-purpose general cargo terminal

(c) Increase in unit-load weight has led to higher-capacity equipment. The flexibility offered by heavy-duty fork-lift trucks with attachments has led to theirgreater use. Large quantities of homogeneous cargoeshave allowed the use of overhead stacking or gantry-cranes.

167. Since such a terminal is designed to serve atransitional phase, it might be advisable-depending onthe traffic forecast-to proceed in two stages. Figure 27shows a layout for a single-berth first phase, in which asingle berth can handle the traffic and when the trafficmix demands a higher proportion of open rather thanshed storage. Figure 28 shows a layout that is moresuitable where there is a higher proportion of shed car-go, where two berths are justified, and where thesecond-phase development areas have been clearlyallocated and partly surfaced. In this version, the tran-sit and consolidation shed must be of a type which canbe dismantled and re-used with additional material forthe erection of two sheds further back during thesecond phase.

C. Equipment

168. The main method of ship handling is either byship’s gear or by mobile tower crane. No rail-mountedportal cranes are normally provided and only one gan-try-crane in the first instance. A 30-ton mobile towercrane may, however, be on the same rails as the gantry-

crane. The standard method of transfer for virtually allclasses of cargo is by tractor/trailer combinations, usingtrailers of a size generally associated with containeroperations but without corner fixings, of a low profiledesign, and equipped for easy coupling and uncoupling.While the cost of equipment listed in table 4 is substan-tial, it can be readily justified. This cost is included in

TABLE 4

Handling equipment required for multi-purposegeneral cargo terminals

Srngle berh. TWO.bWd,firrr phase, flirt phase. Two-berthokmon”. 1 n,,er”on”~ 2 remind

rprrdamlnonlly (predominunrly secondopn sroragr, rhcd srorope, phaw

35ton g a n t r y - - 130-ton heavy lift crane ,_ 1 1 120-ton mobile tower crane

(for ship working) 1 2 2IO-ton mobile tower cranes

(for ship working) 2 2 220-ton mobile cranes

(for yard working) 1 - 1J-ton mobile cranes

(for yard working) 1 2 2Straddle-carriers _. 23-ton fork-lift trucks 8 15

315

lo-ton fork-lift trucks 2 3 5Tractors (tugmasters) 3 6 6Trailers/chassis 9 1 8 1 8Rolro ramp 1 1 1

156

FIGURE 27

Firs1 phase of the multi-purpose terminal, alternative 1

I’

1~

’ ;

c

II I I

OPEN STORAGE , OPEN STORAGE IAREA

5.000 Ill2I ARE*I 5.000 dI

I II

~ L---------l L-------J@

the total terminal cost estimate given above. The listgiven is for the initial equipping of the terminals illus-trated. Perhaps the main reason for difficulties in theoperation of unitized cargo terminals has been the fai-lure fully to recognize the need for transfer equipment,and for this reason the quantity of transfer equipmentsuggested should not be reduced. As a particular trafficdevelops, the terminal may start to take on a morespecialized role and further equipment (such as addi-tional container gantry-cranes and, straddle-carriers)may be justified.

D. Management

169. To take full advantage of the multi-purposeterminal, a modern port management approach isneeded. At the planning stage, special considerationshould be given to the new status of the dock worker,and to the need for integrated planning of the opera-tion. One of the most sensitive areas in a changing port

environment is the status of the dock worker. Earlyaction on the part of management can help to pave theway for a gradual change towards an improved labourmanagement policy. The mangement effort in this re-spect should include:

(a) Training of specialized personnel (drivers ofmechanical equipment, mechanical and electrical tech-nicians for equipment maintenance, traffic controllers);

(h) Advance planning of the requirements for man-ual and office workers, with a regular revision of thequotas required;

(c) Gradual improvement of the status of the dockworkers by conversion from a casual to a permanentworking force, at least for a substantial proportion ofthe workforce;

(d) Development of a time-based payment system,incorporating adequate social security provisions.

170. The port management must fully involve theunions in these developments and be willing to acceptproposals from both manual and office workers.Changes will always occur more smoothly if there hasbeen extensive consultation.

171. Another area of preliminary action concernsthe operational organization of the terminal. Often, theactivities on the ship, on the quay apron and in the shedhave been considered as separate activities. The netresult, even in the case of break-bulk general cargohandling, has been a considerable loss in operatingcapacity. At a specialized terminal, such separation iscompletely unacceptable, as a unified responsibility forthe overall operation and unity of control of the special-ized terminal becomes an increasingly important re-quirement for its effictency. On the other hand, it isdesirable that the specialized terminal should be opera-tionally independent of the conventional break-bulkberths.

172. Management methods should concentrate oncontrol and continuous monitoring, of the type associ-ated with specialized container operations, for all traf-fic handled. This will require provision to be made atthe planning stage for the following:

(a) Management training;

(h) A supporting administrative organization withplanned information flow;

(cJ The planned preventive maintenance of equip-ment based on good repair facilities;

(d) The collection and use by management of statis-tical performance indicators. as suggested in theUNCTAD publication on the subjects;

(e] Close collaboration with shipping agents, for-warding agents and railways, which should have repre-sentatives at the terminal.

’ Pm Perforn~ance Indicators (Umted Nations publication. SalesNo. E.76.11 D.7).

157

- -- -

F IGURE 28First phase of the multi-purpose terminal, alternative 2

I i I I/ I ,L--l L--d

r ----r--l---- -l[ TRANSIT AND CONSOLIDAT,ON SHED12.000 Ill2 IL -II-L-I--- -l

APRONL ----__---_

0

158

Chapter V

TERMINAL REQUIREMENTS FOR ROLL-ON/ROLL-OFF TRAFFIC

A. The role of roiro services

173. The spread of roiro services to the deep-seatrades is a development which will be of increasing im-portance to developing countries in view of the greatflexibility of the operation. As of mid-1980, the deep-sea roiro fleet consisted of 220 vessels totalling just over3 million dwt. The deep-sea fleet is predominantly ayoung fleet, with only 20 ships in existence before 1970,and a total of 125 ships entering service between 1977and 1979. The most popular type is the pure roiro (55per cent of total dwt) followed by roiro general cargo(23 per cent) and roiro container ships (20 per cent). Bymid-1980 there were 63 vessels of 1.12 million dwt onorder that could enter the deep-sea roiro fleet over thenext 2 112 years, representing an increase of 37 percent.

174. In mid-1980, 45 per cent of the fleet consistedof vessels up to 9,999 dwt, 31 per cent between 10,000and 19,999 dwt and 24 per cent over 20,000 dwt. Thetrend towards increasing vessel size can be expected tocontinue in the long term as roiro operations extend tomore long-haul trades and those high-throughputtrades where larger vessels will be used for larger load-ing per sailing.

175. As listed in part one, chapter III (“Trafficforecasting”), the variety of cargo types which can becarried on roiro vessels-in various combinations-in-clude vehicles, loaded road trailers or semi-trailers andcontainers on chassis, as well as any general cargo onpallets or flats which can be carried on and off the shipby fork-lift trucks. In addition, roiro vessels are oftenused to carry passengers. Moreover, the majority ofrolro ships are equipped for a percentage of lift-offoperations for containers and heavy lifts, and in somecases also for bulk cargo. Because of the priority berth-ing which is often given to this type of service, it canbypass port congestion ship delays. Furthermore,where quays have a suitable load-bearing capacity,large, long, heavy or awkward loads can be workedwithout special heavy-lift cranes, and in certain caseswith less berth length.

176. Several types of vessel of varying sizes are inoperation. Vessel design differs with respect to theramp facility, which may be placed at the stern, in thebow or on the side. The ship itself may dock eitheralongside a quay or at right angles, for access throughthe bow or the stern. Cargo is carried on several decks,and access is often provided between these decks byramps or elevators within the vessel. In some cases,connections can be made to the shore at each separatedeck level.

177. In general, for liner deep-sea trades, threemain types of ship can be identified:

(a) Type 1: roll-on/roll-off ships with multiple decksand/or holds with side-ports requiring a quay ramp;

(b) Type 2: roll-on/roll-off ships with a ship-basedangled stern ramp;

(c) Type 3: mixed roll-on/roll-off, lift-on/lift-offships requiring a quay ramp.’

178. Ships of the second type, with a ship-basedangled stern ramp and multiple decks connected byramps, are of particular promise for developing coun-tries. The need for sophisticated and relatively expen-sive port-based link spans is avoided, while a large var-iety of cargoes can be handled. Moreover, these shipsoften employ their own fleet of straddle-carriers, fork-lift trucks and other mechanical handling equipment.Hence the investment cost for the port is considerablyreduced.

179. An examination of the development of cellularcontainer services and ro/ro services shows that, be-cause of local conditions and differences of approach,the two modes of carriage are in competition on a num-ber of trade routes. However. the true economics of thesituation are likely to show that there is room for bothon the major routes where there is at present competi-tion. The economics of container services are such thatthey will usually capture all substantial containerizablecargoes, leaving non-containerizable general cargo tobe carried by conventional means. As traffic grows, apoint is reached where this residue becomes sufficientlysubstantial, or cargo-handling cost and ship waiting-time cost sufficiently great, for this merchandise to bedivided into the “cream” cargo, cargo of higher valueneeding rapid handling, and the remainder. The“cream” cargo will tend to be carried on roiro servicevessels.

180. Often, the more important factors are flexibil-ity and the cutting-down of port investment, particu-larly where there are smaller traffic volumes, as inmany ports in developing countries. Here, there is nocompetition between cellular container services and roiro services, and the roiro ships will therefore be equip-ped to carry whatever container traffic there may be.

9 further informatmn is gwen in an ICHCA Survey of 1978 entItled,qo.Ro Shore and Shrp Romp Charactenshcs and in a 1978 report ofthe PIANC lmernatmnal Study Commission on the Srandardlsationof Roll-on/Roll-off Ships and Berths (Supplement to Bulletin No. 33(Vol. 1111979)).

159

181. It is also interesting to note that operatorschoose the roll-on/roll-off vessel for a specific com-modity and not for the more diversified cargo-mix ofthe traditional liner trade. For example, automobilesmay be carried on the outward voyage and forest pro-ducts on the return voyage; or, say, steel products maybe transported by roiro vessel between ports of thesame country. In such cases, cargo flexibility is a lesscritical factor than cargo-handling productivity and theease with which changes can be made in ports of call.

B. Roiro demand forecasting

182. In any attempt to forecast the extent to whichroiro services will penetrate a given route, the followingtwo principal characteristics of the roiro service asopposed to the container service should be borne inmind:

(a) The ability of a ro/ro service to attain high cargo-handling speeds in a highly developed port at one endof the route and satisfactory speeds in a conventionalport at the other end;

(b) The ability of a roiro service to switch its ports ofcall easily in an area of changing trading patterns be-cause it requires the minimum in the way of special portequipment.

183. At the same time, when a route capacity buildsup to the point where a cellular container service isintroduced, a roiro service will in general be phasedout. This will happen because the carrying capacity of aspecialized container vessel can be more fully used thanthat of a ro/ro ship. In broad terms, the nature of roirocargo is that it is the high-value portion of the miscel-laneous cargoes left over after containerization.

C. Berth requirements

184. Thus, apart from the need for good access andsuitable storage areas, roiro operations place little de-mand on ports for speciahzed facilities and can be fullyself supporting in smaller ports. However, this veryflexibility means that it is difficult to forecast whichclass of rolro ship, carrying what cargo mix, will use anyparticular port.

185. Since a ro/ro berth can be prepared and equip-ped more quickly than most other kinds of berth andsince, in many cases, the ship design will be known, theshore facilities should be designed to meet the ship’sneeds. But it is important to recognize that a berth willoutlast most ships and that ships may be moved to otherroutes if traffic patterns make it desirable to do so.Therefore berth planning should be as flexible as poss-ible, even though only one vessel type is expected at theoutset.

186. Four alternative fixed layouts are shown infigure 29. Alternative 1 offers a high degree of flexibil-ity for the future, since it is easily converted to thehandling of other types of ship, but a portion of thequay length is lost (usually about 60 metres). The totalquay length necessary is large and represents a costlyinvestment.

FIGURE 29

Alternative layouts for a rolro quay

I 2.

4 .

187. Alternative 2 is feasible only if the length ofthe vessels calling at the port remains unchanged duringthe lifetime of the facility (30-40 years). In general, thiscannot be guaranteed, and, given the trend towardslarger ships, few ports may be prepared to take the riskof building a quay which might become inadequatewithin a time span of five to ten years. However, itsadvantage is that it separates traffic flows on the quay.

188. Alternative 3, although the least expensive incost terms, is not generally appropriate since it can beused only for roiro vessels with stern or bow cargo-handling arrangements. This eliminates a large numberof ships and any lift-off operation.

189. Alternative 4 has a number of advantages. Itcombines the flexibility required to handle differenttypes of ships with the possibility of receiving vessels ofincreasing length. This staggered layout for two berthsis a natural development of the single roiro cornerberth, which is the preferred layout when only one roiro ship at a time is to be handled. The typical layout ofthe single corner berth is shown in figure 30.

160

Preferred layout of a single roiro corner berth

Adjacent berth

r -Unrestr ic ted access Lift&f or sidepart possibility

Substantial areafor parking and storage

I

L EWlOSUle- - -

190. A roiro berth needs to be in a well-protectedlocation in a port. Although some down-time can beaccepted at any berth in a port, roiro traffic is, morethan any other, dependent for its overall transporteconomy on rapid turn-round times and it can bemore seriously affected by swell and by tides than alift-off operation.

191. In a location where there is no tide, roiro fac-ilities can dispense with adjustable ramps and are verycheap to construct. The simplest form of roiro berthcomprises a surface on to which the stern or bow rampof a ship is lowered during loading/unloading. A slew-ing or fixed quarter ramp allows a roiro ship to use anormal berth and can be supported by a system of ten-sion cables, with an automatic winch which limits press-ure on the wharf. Figure 31 illustrates the typical designfor a slewing ramp, which gives the ship a greater flexi-bility in berthing choice. In high tidal ranges, the neces-sary adjustable bridge ramp and supports add consider-ably to the cost of the basic facility. With a tidal rangeof 5 metres, a bridge ramp from 25 to 50 metres long”

ID The exact length depends on the maximum difference in ekva-tion between the ship’s exit and the quay surface.

161

wouldtrucks

- Ibe needed, capable of carrying the heaviestand trailers. Under such conditions, the econ-. .

omit and operational posstbihty ot an enclosed dockshould be examined, as discussed in part one, chapterVII, “Civil engineering aspects”.

192. In more sophisticated systems, an adjustablebridge ramp forms a suspended roadway hinged at theinshore end and supported near the outer end to pro-vide a connection between the shore approach and theship. The outer end may have a telescopic or hingedconnection. There is, therefore, a much greater interac-tion between ship design and berth design than formany other maritime facilities.

193. Several basic designs have been put forwardfor the bridge ramp, which differ essentially in themethod adopted for the adjustment of the ship end ofthe bridge ramp to accommodate changes in level dueto loading and discharging and tidal fluctuations. Twoalternatives are normally considered. The first consistsof a floating pontoon or bridge ramp which automatic-ally rises and falls with the change of tide. Figure 32illustrates one form of this bridge ramp. The secondpossibility is for the ship end of the bridge ramp to be

FIGURE 31

Example of slaving ramp for rolro service

connected to a fixed gantry structure either by cables orby hydraulic means, which provide the necessary ad-justment.

194. An important feature of a floating bridge rampis its capability of being moved from one part of thequay wall to another. This is desirable in many cases, toincrease berthing flexibility. It is usually possible to towpontoons to other locations fairly quickly.

D. Terminal area requirements

195. One characteristic of the roiro terminal is theneed for adequately fenced, protected and surfacedstorage areas with a wide, well-paved access way. Thetransit storage area needed for a ro/ro terminal may beeven larger than that needed for a container terminal,which is normally 10 hectares per berth. To determinethe storage area requirements, the ro/ro cargo forecastsshould be grouped under the following four headings:”

(a) Containers;(b) Cargo carried by intermediate methods;(c) General cargo;(d) Wheeled cargo.

196. The container forecast is in TEU units andtherefore the container terminal planning chart I, forthe container park area, can be used. The appropriatearea requirement per TEU factor, together with otherfactors such as transit time, will allow the planner tocalculate the corresponding area requirements for thero/ro terminal.

” See part one, chapter III. section F, on forecasting cargoes car-ried by roiro ship.

FIGURE 32

Example of adjustable bridge ramp for rolro service

l-i

E L E V A T I O N A

E L E V A T I O N B

GUIDE COLUMN CONTROL STATION-- -_--___----

S E C T I O N c c

162

FIGURE 33

R&o terminal planning chart: vehicle storage area

I, , I I,, , L, , , , , , , , 0

-

I”

IS -

*o -

197. The storage area requirements for the secondand third categories of roiro cargo can be determinedby using the break-bulk terminal planning chart III forstorage area requirements. The appropriate stowagefactor, stacking height and transit time must be used foreach category.

198. The area requirement for roiro wheeled cargocan be determined from the roiro terminal planningchart for vehicle storage area, illustrated in figure 33.Typical area requirements, excluding access area, forvarious road transport vehicles are as follows:

Articulated truck, 15.metre

Rigid truck, 16ton .._... ,.......

Automobilelargesmall . . ,._..............

46.5

26.5

1 1 . 07.0

A sufficiently large area should be allocated to thiscategory of cargo to accommodate the largest shipmentof vehicles envisaged. For example, a shipment of 500small automobiles would require a minimum area ofapproximately 4,500 square metres, assuming a 2.5 percent allowance for access.

E. Roiro terminal equipment

199. Transfer and stacking operations are carriedout with a large variety of equipment on one terminal.For transfer operations, the main piece of equipmentwill be the port terminal tractor. The tractor will havethe ability to haul a fixed load up a specified gradient ata certain speed, as well as a port-adapted, heavy-dutyfifth wheel to allow crossing ramp connections. Thisfifth wheel will have lateral inclination allowance and alocking device to reduce torsional stress. The cab of thetractor will have swivelling controls or dual seats forforward and reverse manoeuvring.

200. Other equipment used for both transfer andstacking would be low-profile straddle-carriers andheavy-duty fork-lift trucks with a low-profile cab andtriplex mast.

201. For working in the ship’s hold via side ports,an electric fork-lift truck is preferable to a diesel-drivenvehicle. Slopes and cambers can reduce fork-lift per-formance seriously. The gradient should never exceed 1in 10. For example, where there is a slope both to theship’s deck and to the shed or stack, battery-drivenfork-lift trucks may need recharging three times in oneshift, and diesel lift trucks are more appropriate.

164

Chapter VI

TERMINAL REQUIREMENTS FOR BARGE-CARRYING VESSELS

A. Barge-carrier systems

202. The impact of barge-carrying vessels on portoperations in developing countries is discussed in moredetail in the reports of the UNCTAD secretariat ontechnological change in shipping and its effect on ports,which have already been referred to several times.”Five types of barge carriers are in commercial service:BACAT, LASH, BACO, SEABEE and Danube SeaLighter. The LASH system is the one chosen by themajority of lines. The principal dimensions of the bargecarriers and their barges are given in tables 5 and 6.

203. The barge carrier requires few, if any, portfacilities and is designed to discharge offshore its cargoof loaded barges, which are then moved by tug eitherinto port or into an inland waterway system. The car-rier is then free to accept pre-loaded barges for thereturn trip. The great advantage is that the carrierspends most of its time at sea and is not penalized byinadequate facilities or congestion.

204. In practice, however, these systems have notproved themselves, largely because few barge carriershave been operated on the type of routes for which theywere designed. In addition, the almost parallel de-velopment of containerized and roiro handling systemshave proved more versatile and, in the long run, cheap-er to operate.

205. The most successful barge-carrying operationsto date have tended to be between highly industrializedregions, namely between the United States (region ofthe Gulf of Mexico) and northern Europe. Otherroutes are between Europe or the Gulf of Mexico andthe Middle East. A new operator is the Soviet Inter-lighter joint venture, which has a service linking theDanube river ports via the Black Sea to India, Pakis-tan, Malaysia, Viet Nam and Kampuchea. Two newbarge carriers will provide, with two tug units, feederservices for the existing ships.

206. The other barge carrier operator is the Baco-Liner company. The ships utilize opening bow doors tofloat on and off BACO barges 24 metres long, eachcapable of loading 800 tons. The free upper decks canbe used to stack TEUs in three tiers.

207. As table 5 shows, barge carriers may be equip-ped to carry containers or may be pure barge carriers.The former vessels are provided either with cellularholds or special frames for the carriage of containers ondeck and they have a ship-based gantry-crane for hand-ling the containers.

I2 TDIBIC 41129 and Supp 1-6.

165

B. Barge-carrier handling requirements

208. The initial idea of barge carriers was that thebarges should be loaded and discharged from themother ship while the latter was at anchor outside theport, and that the cargo carried by the barges should beloaded and discharged at any shallow-draught berth,tugs being used for towing the barges to the berth.Thus, aside from tugs, the port facilities required wouldbe minimal.

209. In practice, more sheltered water has beenfound desirable for the purpose of loading and unload-ing the barges, and the mother-ship operation normallytakes place inside the port area-at moorings, along-side container or break-bulk berths, or even at a specialT-shaped jetty. In either case, a deep entrance channelis required; in addition to the operating draught of thevessel, a minimum of 1 metre must be allowed for trimchanges during the operation. The water areas requiredfor the manoeuvring of such large vessels are also sub-stantial, as is the area needed around the mother vesselfor manoeuvring the barges.

210. Furthermore, barge carriers with a cellularcontainer complement must call at a terminal with faci-lities for handling containers.

C. Barge-handling requirements

211. Handling the barges within the port requires“barge park areas” which are large water surfaces, wellseparated from the other water-based traffic in theport, where laden export barges await shipment, ladenimport barges stay until such time as they are sent in-land or can be discharged, and empty barges are kept instock. The area needs careful attention from the pointof view of port security.

212. The requisite size of a park area can be consid-erable, since the inland penetration of the barges is atpresent low, and thus the great majority are destinedfor port loading and discharge. Although large waterareas may be available in river ports, in breakwaterports the lack of water area proves a major impedimentto the smooth functioning of the barge-carrier service.As a rule of thumb, a minimum barge park area of10,000 square metres should be provided, this areaallowing for an average discharge of eight barges percall and a peak of 25 barges.

213. In ports where the necessary areas have beenprovided. significant investment costs have been in-volved. At Bremerhaven, 31 pontoons have been con-structed, offering mooring space for 140 barges. The

TABLE 5

Principal barge-carrier dimensions

BACAT SYSTEM:Mackinnon-Mackenzie & Co.

Bacat 1 ........................... 2 682LASH SYSTEM:

Central Gulf Lines Inc.Acadia Forest ................... 48 303Atlantic Forest .................. 48 327Bilderdyk ........................ 44799William Hooper .................. 46 892Button Gwinnett ................ 46 892George Wythe ................... 46 890Spruce (non-propelled) ........ 2 600Oak ................................ 11550Willow ............................ 11496

Condock RedereiCondock I ........................ 3 170Condock II ....................... 3 170

Delta Steamship LinesDelta Caribe ...................... 30 292Delta Mar ......................... 41048Delta Norte ....................... 41 048Delta Sud ......................... 41 048

Prudential Lines Inc.LASH Italia .................. ... 30 298LASH Atlantic0 ................. 30298LASH Pacifico ............... , ... 30 298

Waterman Steamship Corp.Robert E. Lee .................... 41 578Sam Houston ..................... 41 578Stonewall Jackson ............... 41578Benjamin Harrison .............. 21 500Edward Routledge .............. 21 500

NavilashOne on order ..................... 9 640

BACO SYSTEM:Baco-Liner GmbH

Baco-Liner 1 ..................... 21 801Baco-Liner 2 ..................... 21 801Baco-Liner 3 (on order) ......... 21 800

SEABEE SYSTEM:Lykes Bras. Steamship Co.

Doctor Lykes ................... 39 026Almeria Lykes ................... 39026Tillie Lykes ....................... 39 026

DANUBE SEA LIGHTER SYSTEM%Interlighter

Juluis Fucik ....................... 31850Tibor Szamueli ................... 31850Two on order ..................... 8 563

103.5 18.8 5.4 13 -

261.4 32.6 12.1 8 0261.4 32.6 12.1 8 0261.4 32.3 11.3 83272.3 30.5 12.4 8 9212.6 30.5 12.4 8 9272.3 30.5 12.4 89112.7 34.2 3.4 15134.5 34.2 4.8 18134.5 34.2 4.8 1 8

---

-

--

---

-

--1 0 81 0 8

92.4 19.6 4.6 3 - 38392.4 19.6 4.6 3 - 383

249.9 30.5 10.7 7 0 - 840272.3 30.6 11.6 8 5 12 1728272.3 30.6 11.6 85 72 1 728272.3 30.6 11.6 85 72 1728

249.9 30.5 12.4 7 0249.9 30.5 12.4 7 0249.9 30.5 12.4 7 0

-

-

840840840

212.3 30.6 11.6 8 9272.3 30.6 11.6 89272.3 30.6 11.6 8 9272.3 30.5 11.6 8 0257.6 30.5 11.6 8 0

--

-

-665655

n.a. n.a. La. 22 -

204.1 28.5 6.7 12 501 501204.1 28.5 6.1 12 5 0 1 5 0 1204.1 28.5 6.1 12 501 5 0 1

267.0 32.3267.0 32.3267.0 32.3

3 8 4w 18003 8 400 1 SW3 8 400 1 800

266.5 35.1266.5 35.1n.a. n.a.

11.911.911.9

11.011.0n.a.

2 6 720 1 5522 6 720 1 5526 - 5 1 3

total length of the pontoons exceeds 650 metres, andthe total cost of the project was almost $4 million. Thebasin and barge park areas are illustrated in figure 34.

214. Barges can be handled at existing break-bulkand lighterage berths, even of old-fashioned design.However, it might be advisable to provide special hand-ling facilities for the barges where:

(a) Existing facilities are inadequate because they donot provide weather protection or sufficient space forassembling cargo and loading it on to barges;

(6) Existing facilities are fully utilized and the hand-ling of additional barges would lead to congestion;

(c) The distance between the barge park area andthe existing break-bulk berths is excessive;

(d) A combined terminal for handling containersand barges is preferred from a cost-effectiveness andoperational point of view.

215. The higher the cost of labour in a port, thegreater will be the need to build well-equipped andsuitable barge-handling facilities. Only then can theoperations be expected to achieve the considerable in-crease in productivity which is an essential requirementin ports with high labour costs if port cargo-handlingcharges are not to become prohibitive. Similar reason-ing provides an incentive for the increased use of pal-

166

TABLE 6Barge dimensions

BACAT 1 6 . 8 2 4.65 2 . 5 140 1 6 4. . . . . . . . . . .LASH 2.1 3 7 0 5 5 4. . . . . . . . . . . . . . . 18.76 9.50B A C O 24.00 9.50 4 . 1 8 0 0 I 020. . . . . . . . . . . . . .SEABEE 29.72 111.67 3 2 8 4 4 1 10x. . . . . . . . . .

FIGURE 34

LASH facilities at Hremerhaven lets, bundled units and pre-slung units in a barge-carrier operation.

216. In Singapore. a large warehousing complex(providing 200,000 square metres of covered storagespace) at Pasir Panjang, which was built independentlyfrom the barge-carrier development, has now beenpartly set aside for the receipt of cargo from bargecarriers. This development has made it necessary forthe Port of Singapore Authority to install in the PasirPanjang area six mooring buoys, which will permit thesafe anchorage of 120 barges. The buoys are approxi-mately 700 metres apart and are all in line, thus stretch-ing out over 3,500 metres.

217. Although there is thus a variety of alternativesin providing facilities for barge-carrying vessels, com-bined with or indepedent of break-bulk or unitizedberths, indicative planning figures for an annualthroughput of 250,000 tons made up of 1,000 bargeunits with an average cargo load of 250 tons per bargewould be as follows:

Number of moormg areas 1Number of moormg buoys 4Required barge park area (assummg a peak of 50

barges at one time) 20,000 dNumber of tugs required to tow barges between the

mother-vessel and the barge park area (dependingon the distance between them) .,. 3

Number of pontoons (assummg an Inland penetratmnof less than 10 per cent) ..I. 20

Length of quay and area requred to load and dischargethe cargo of the barges In port As for ~WCI

break-bulkberths

167

Chapter VII

DRY BULK CARGO TERMINALS

A. Introduction

218. This chapter is concerned with dry bulk car-goes, but it is necessary first to note that the word“bulk” can be used in two different senses. Tradition-ally, the expression has been used to indicate that acommodity was loaded or discharged in loose or fluidform, for example, grain or petroleum. More recently,however, there has been a tendency to talk about “bulkshipments” in the sense of shipments by the full ship-load or substantial part-load, whether or not the com-modity in question is handled by bulk cargo methods inthe traditional sense. Thus it is now common to speakof “bulk shipments” of steel plates or bundled timber.The term “semi-bulk” is also used, for example, withreference to large shipments of bagged cargo. Thischapter considers dry bulk cargoes in the traditionalsense only.

219. Dry bulk cargo is customarily divided into twogroups, the “major bulk cargoes” and the “minor bulkcargoes”. The major bulk cargoes consist of a group offive commodities which almost invariably move by non-liner methods in full shiploads. In 1980, the traffic inthese products was as follows:

Iron ore .,...GrainCoalBauxitePhosphate ._.

The majority of shipments of these commodities aremade by specialized bulk carriers and combined car-riers (over 40,000 dwt), but general cargo vessels arealso used to a certain extent. When a traditional‘tween-deck vessel is used, however, a severe reductionin handling speed results. Separate descriptions of atypical coal import terminal and a typical phosphaterock export terminal are given later in this chapter.

B. Main characteristics of a majorbulk cargo terminal

220. A radical difference exists between the charac-ter of a major bulk cargo terminal, especially one forthe export of mineral ores, and the average all-purposecommercial port. The requirements with respect tolocation, depth of water, type of infrastructure, layout,equipment, storage facilities and auxiliary services arebasically different from those in a typical general cargo

port. Also, the administrative, operating and labourproblems must be approached in a different way.

221. Unlike a general cargo port, a terminal for theexport of mineral ores does not need to be located closeto the main centres of commercial and industrial activi-ties of the country. The nearest possible distance fromthe mining area, with good land communication, is themost desirable place, subject, of course, to there beingfavourable natural conditions at that sector of thecoast. Depth of water requirements are more stringent,as the trend is towards the transport of most ores in thelargest possible vessels with a draft often in excess of 15metres.

222. Vessels of this size require huge stocks of oreat the terminal and therefore extensive storage facili-ties. In order to minimize expensive ship time at port, itis necessary to ensure a relatively low berth occupancyto avoid the risk of ships having to wait for a berth, anda very high rate of loading while they are at berth. Toachieve the required speeds of loading, a network ofbelt conveyors is needed, linking powerful reclaimersto ship-loaders. The mechanization of cargo handlinghas eliminated the need for a large labour force, andthe uniformity and simplicity of the material handled ata dry bulk cargo terminal means that the many com-mercial services needed at a general cargo berth are notrequired.

223. The handling techniques used allow vessels tobe berthed up to a kilometre or more away from shore,if necessary, with the ores being carried to the ship bybelt conveyors placed on a light structure. A typical oreberth consists of at least two berthing dolphins, twomooring dolphins and some buoys. In-shore of theberthing dolphins, an independent structure supportsthe loading equipment, composed of a ship-loader con-nected to land by belt conveyors. The storage area onland requires the proper equipment for unloading vehi-cles from the mines, for stacking the ores on the stock-piles and for reclaiming ore for delivery by belt con-veyor to the ship-loader. In addition, facilities for directtransport from unloading hoppers to the ship-loadershould be provided.

224. Although the basic elements will remainapproximately the same from one terminal to another,the particulars of the design will vary considerably,according to local conditions, the nature of the materialand the scope of the operation. Normally each installa-tion will have to be designed and built to suit the par-ticular circumstances.

C. Bulk carriers

225. Wherever possible, bulk cargo installationsshould be designed for specific ships known to be call-

168

FIGURE 35

Principal dimensions of dry bulk cargo carriers

n m

ing. Detailed discussions with the shipowners and ship-pers should therefore be held to agree on the require-ments for ship-loaders and unloaders. However, otherships will call and the specifications will need to takeaccount of both maximum and minimum ship sizes.

226. The phenomenal growth of the dry bulk cargofleet in recent years is comparable to the growth, inboth numbers and size, of oil tankers. In the mid-60sthere began a trend towards combination carriers ableto transport two or more different types of commod-ities. Most of the larger vessels are capable of trans-porting both dry and liquid bulk commodities. Bulkcarriers are classified into six types, designated as fol-lows: B (bulk), 0 (ore), B/O (bulk/ore). O/O (ore/oil),OBO (ore/bulk/oil) and OS0 (ore/slurry/oil).

227. Figure 35 gives curves showing the relation-ship between the length overall, beam and full loaddraught. and the dwt, for the majority of dry bulk car-riers. Where information on specific vessels to be em-ployed is not available, these curves are sufficientlyaccurate for preliminary planning purposes.

228. Ideally, all water areas which ships may haveto pass through or lie in should be designed for theirmaximum (fully-loaded) draught. even though theoccasions when ships will enter or leave port at thisdraught will be few in number. However, substantialeconomies can sometimes be made by providing lessdepth than this when there is certainty as to the load-ings to be expected. A rough general relationship be-tween load factor and draught for dry bulk carriers isgiven in figure 36.

229. It is possible for there to be certainty as to thedry bulk cargo loadings to be expected when there is anintegrated transport service, for example, bulk carrierschartered by a chemical works. In such a case. the max-imum load factor and hence the draught can be deter-mined from the known stowage factor of the commod-ity in question and the specification of the ships to bechartered. Planning for a limited draught may also bejustified when the draught of ships arriving or departingis linked to and limited by draught restrictions else-where.

230. The planner should thus be aware that facili-ties designed for a fully loaded lOO,OOO-dwt carrier mayalso have to handle a partially loaded 200,000-dwt car-rier. While the draught limitation of the entrance chan-nel is overcome by the reduced load factor of the ves-sel, the beam and length may prevent the vessel work-ing at the terminal. This factor should be borne in mindwhen specifying mechanical handling equipment. Thefacilities may also be required to handle smaller vesselsand appropriate steps would be necessary; for example,fendering may need modification.

D. Bulk handling equipment performancespecifications

231. The exact meaning of the manufacturer’s per-formance specification for a piece of bulk handlingequipment must be understood by the planner of a ter-minal. In fact, the various items of equipment for bulkcargo handling are subject to wide variations in per-formance. This applies particularly to ship unloadersand reclaimers.

232. In the case of a grab unloader, for example,the discharge rate depends on all of the following fac-tors:

(a) Volumetric capacity of the grab;

(b) Density and nature of the material;

(c) Grab hoisting speed and acceleration;

(d) Trolley travelling speed. acceleration andbraking;

(e) Skill of unloader operator;

cf) Shape of hold and hatch opening;

(g) Method of trimming in the hold;

169

-- -

FIGURE 36

Operating draughts for different load factors against dwt for dry bulk cargo carriers

(h) Ship’s beam and unloader outreach;(i) Depth of hold and tidal height;(,i) Travel distance from ship’s rail to hopper.233. Thus there is little meaning to a capacity figure

for an unloader taken in isolation from the ship and thelayout of the installation. The following three capacitiesshould be defined in proposals, tender requests anddesign specifications: (a) peak capacity; (b) ratedcapacity; (c) effective capacity.

234. The peak capacity is defined as the maximumhourly unloading rate which can be achieved by theunloader when the cross traverse and hoisting distancesin the unloading cycle are the absolute minimum, forexample, when a full ship at the highest tide is discharg-ing to a full hopper, and when the operator can exploitthe maximum capacity of the hoisting and traversespeeds with a full grab. This rate is the capacity towhich the connecting belt conveyors and weighersshould be designed in the absence of other overridingeconomic factors.

235. The rated capacity differs from the peakcapacity: it is the unloading rate during unloading froma specific point in a vessel. This point is generally lo-cated, horizontally, at the centre of the vessel to beunloaded, and vertically, at mean low water level forthe port. The payload of the bucket divided by the timetaken to perform one cycle from the digging point tothe receiving hopper on the quay and back gives therated capacity. This figure is a useful definition for thecomparison of equipment proposals and the classifica-tion of alternative solutions to a specific requirement.

236. The effective capacity is the average hourlyrate of tonnage discharged during the unloading of theentire cargo of one ship, taking into account the time

lost in trimming, cleaning up, moving between holdsand the requisite breaks during the working periods,but excluding scheduled non-working periods, for ex-ample night-time and weekends. The effective rate isthe figure used for port planning. The ratio of the effec-tive capacity to the rated capacity gives the through-ship efficiency factor which for grabs is usually about 50per cent. The effective rate and the factor for the frac-tion of time berthed ships are worked per day are usedto determine the daily throughput and then the averageship service time.

237. The “peak capacity” and “rated capacity” arealso known as the “cream digging rate” and the “freedigging rate” respectively. In a typical case, where thepeak capacity is 2,500 tons per hour, the rated capacitymay be 2,000 tons per hour and the effective capacitynot more than 1,000 tons per hour. The effective un-loading capacity can be even lower than 40 per cent ofthe peak capacity if the ship has unsuitable holds, nar-row hatches and bad conditions for trimming.

E. Ship loading

238. Ship-loading systems are simple in comparisonwith ship-discharging systems. They normally requireonly a feed elevator or conveyor, a loading chute andthe force of gravity. With such technically simple sys-tems, phenomenal rates can be achieved. Other loadersare fitted with flight conveyors or spiral chutes to re-duce the degradation of friable materials, or with tele-scopic tubes fitted with chutes or centrifugal slingerbelts for distributing the material in the hold. Ship-loaders can normally be positioned adjacent to thehatch to be loaded, and they receive the material fromhigh-capacity belt conveyors. The loading boom can be

170

FIGURE 37

Example of travelling ship-loader with material from high-level conveyor

hoisted or lowered to suit the height of the vessel beingloaded. In addition to continuous loading with a ship-loader, grabs can also be used for loading bulk cargoes.

239. Ship-loader capacities are usually limited bythe other parts of the installation such as the conveyorsor reclaimers, but normal capacity ranges are between1,000 and 7,000 tons an hour. In special cases, 16,000tons per hour handling ship-loaders are possible forvery large bulk vessels. At higher loading speeds, thelimit may be imposed by the rate at which the ship canbe de-ballasted.

240. Ship-loaders are designed to permit the holdsto be loaded in a definite sequence to avoid puttingstructural stresses on the vessel. Telescoping spouts atthe end of the boom are frequently provided to directthe discharge into specific parts of the vessel. The boomcan be raised to pass clear of a vessel’s superstructurewhen changing from hatch to hatch, but this may re-quire the conveying system to be stopped in order toprevent spillage of material. To avoid this, the materialcan be conveyed into a surge hopper at a point beforethe loader and returned to the normal flow when load-ing is resumed. The loader belts must then run fasterthan the supporting conveyors to handle the additionalflow.

F. Types of ship-loaders

241. The travelling loader (see figure 37) is on agantry running parallel to the quay. The ship-loader is

usually fed by a conveyor with a movable tripper. Thetripper feeds the material from the conveyor to theship-loader boom conveyor. The ship-loader consists ofa mast superstructure from which a hinged boom issuspended. The boom is raised or lowered to suit thevessel and to clear the vessel’s superstructure whenmoving from hatch to hatch. The vessel end of theboom can be constructed to telescope or a shuttle sec-tion can be arranged to travel inside the fixed boom. Atake-up system must compensate for variations in beltlength due to the boom movements. A design featureof this type of loader is that there is only a slight shift ofthe centre of gravity within the structure for all the jiband boom movements, and the loader can therefore beplaced on somewhat narrower rails than other types.

242. The radial loader was developed for use as anoffshore unit and consists of a pivoted boom which canrotate or slew through an angle of approximately 90degrees about one end, whilst the other end is carriedon a curved track supported on suitable piles. Theboom supports a conveyor which extends over the ves-sel. This section, in addition to travelling backwardsand forwards, can also be made to luff. Material isdischarged from the approach arm conveyor at the pi-voted end of the boom conveyor, where. if required, asurge hopper can be located.

243. The main advantage of slewing bridge-loadersas compared with the travelling loaders is the lowercapital cost of the total installation, that is, of the load-er and related conveyors, together with the marinestructures. Another favourable feature is that it is

171

easier to enclose the conveyor belts and transfers and toinstall dust control systems. A disadvantage is that thistype of loader can completely fill, without final trim-ming, only a modern bulk carrier with no intermediatemasts and derricks. This prevents carriers which are SO

equipped from using the terminal.244. The liner loader achieves the same purpose by

a combination of translation and rotation (the twomethods are shown in figure 38); when the front tum-table travels on a linear runway parallel to the ship, theturntable pivot is allowed to slide as well as rotate.Construction is usually simpler and less expensive witha straight runway rather than a curved one, and shipcoverage is increased.

245. The travelling and slewing type of loader is acombination of a radial and travelling unit. It is particu-larly suited for use on both sides of a “finger” jetty, i.e.one extending out to sea with berthing facilities oneither side. A travelling gantry with a rotating super-structure has a luffing boom conveyor which is fed froma jetty conveyor centrally located between the travel-ling gantry rails. By means of a tripper, the material istransferred from the jetty conveyor to a receiving hop-per located over the pivoted end of the boom.Although only one vessel can be loaded at a time, the

FKXJRE 38

Radial and linear loader comparison

160 Ill IHATCH COVERAGE

Radial loader

I 220 m

HATCH COVERAGE

Linear loader

fact that vessels can be berthed on both sides of thejetty can eliminate delays in operating due to berthingand de-berthing. This may be important under condi-tions of high berth occupancy and tight scheduling.

246. The fixed ship-loader is generally used forsmaller installations. As the vessel size is usually small,the output rarely exceeds 500 tons per hour. The move-ment of the loading boom between hatches is eithernon-existent or restricted, and it is therefore necessaryto move the vessel. This may not present any problemswith the smaller type of vessel having two or threeholds only, and has been used extensively for the ex-port of raw sugar.

247. The approach conveyor from the land is car-ried to the berth on a series of trestles and terminateswith a tower structure. The conveyor is either extendedin a short sliding section terminating with a telescopicchute or is carried in a luffing boom fitted with a tele-scopic chute. In some cases a limited amount of radialmovement is provided to enable the whole area of thehatch opening to be covered and so reduce the amountof final trimming.

G. Ship unloading

248. There are four basic systems available to theterminal operator for the discharge of dry bulk ma-terial: grabs, pneumatic systems, vertical conveyorsand bucket elevators. For a throughput per unit of be-tween 50 and 1,000 tons per hour, pneumatic or verticalconveyor systems are adequate. For throughputs from1,000 up to 5,000 tons per hour, grabs or bucket eleva-tors are the only alternative. Grabs are the most widelyused methods of loading and discharging bulk cargoes.

1. GRABS

249. The main principle of unloading bulk com-modities by grab has not undergone any change in thepast 50 years. However, the grab is now normally usedonly for picking material up from the vessel hold anddischarging it into a hopper located at the quay edgefeeding on to a belt conveyor, as illustrated in figure 39.In previous practice the grab trolley travelled further,discharging to the stockpile.

250. The attainable handling rate for each grab isdetermined by the number of handling cycles per hourand the average grab payload. The time of a handlingcycle is a function of the hoisting speed and accelera-tion of the grab bucket, the travelling speed andacceleration of the trolley, the horizontal and verticaldistances and the closing time of the grab. Further fac-tors affecting it are the skill of the operator, the prop-erties of the material being handled, the shape of thehatches and cargo holds and the degree of cleaningrequired at the end of each hold-emptying. Operatorfatigue in any case places a limit of about 60 cycles perhour. Two operators can be provided, each workingalternately for one hour.

251. For a given lift capacity, the main method ofincreasing productivity is increasing the payload/dead-weight ratio of the grab bucket. The normal ratio is l:l,

172

FIGURE 39Travelling overhead trolley unloader grabbing crane

but newer high-capacity designs are approaching 2:l. Abulk cargo terminal handling a range of commoditieswill require a set of two or three grab buckets for eachcrane (one on the hook, one on standby and/or one inrepair), plus a set of grabs for each commodity whichhas significantly different physical characteristics. Thenumber of available designs is very large, ranging fromthe light grabs for handling products such as animalfeedstuffs and grain, to the massive 50.ton-lift orehandlers. Specialist advice should therefore be soughtto allow the choice of the correct unit for a specificmaterial and crane type, and for specific working condi-tions

252. To achieve the desired rate of unloading, it isoften necessary for a single vessel to be served by twounloaders. This has an important advantage in provid-ing operating capacity during the failure of one of theunits.

253. The principal materials for which the grabbingbulk unloader is used are the main bulk products,namely, iron ore, coal, bauxite, alumina and phosphaterock. Other commodities handled by smaller mobilegrabbing cranes include raw sugar, bulk fertilizers, pet-roleum coke and various varieties of bean and nut ker-nels.

254. There are three main forms of grabbing crane.The travelling overhead trolley unloader (see figure 39)has a cantilevered boom which projects over the hatch.The trolley transfers the bucket from the hold to thehopper on the quay, The structure travels parallel tothe quay to allow working the full length of the ship.Typical free digging rates for these units range from 500to 2,000 tons per hour.

255. The revolving grabbing crane, as shown in fig-ure 40, is generally of the level luffing type and is prob-ably the most commonly used type for unloading. Thecrane grabs and lifts the material and discharges it into

173

a hopper, generally at the front to eliminate slewingduring operation. The hopper feeds a jetty conveyor inthe usual way or it can discharge directly to trucks orrail wagons. These cranes can attain a free digging rateof between 500 and 700 tons per hour. When a normalgeneral cargo crane is being used for grab unloading,the hopper must be located on the same track as thecrane. The 90-degree slewing movement for each grabcycle limits the free digging rate to 250 tons per hour, agood average rate being about 180 tons per hour.

256. The third form of grabbing crane is the mobileport tower crane which is useful in smaller ports hand-ling a wide range of mixed cargoes to and from smallervessels. This unit comprises a standard mobile cranewith an additional tower structure fitted with an ele-vated cab to allow the operator to look down into theship’s hold. Productivities are similar to those achievedwith the revolving grabbing crane.

2. PNELJMATICSYSTEMS

257. Pneumatic systems are suitable for handlingbulk cargo of comparatively low specific gravity andviscosity such as grains, cement and powdered coal.Pneumatic equipment is classified into vacuum, or suc-tion types and pressure, or blowing types. The formerare suitable for collecting materials from several placesto one spot while the latter are suitable for deliverjngcargo from one spot to several places. However, theblow type tends to create dust problems. A combina-tion of the two systems is also used, but it is generallyrestricted to portable equipment. Typical uses of thisequipment are shown in figure 41.

258. Vacuum pneumatic conveyors are simple inconstruction and materials are not lost through spillageduring transportation. However, the power consump-

FEURE 40

Revolving grabbing crmw

tion is high compared with other transporting media.Before a decision is taken whether to adopt a pneuma-tic handling system or a conventional mechanical hand-ling system, not only must the capital, maintenance andoperating costs be considered, but also health, cleanli-ness and other factors which cannot be directly evalu-ated.

259. Certain materials are potentially dangerousand should be handled carefully to ensure the health ofthe operators. Some hazards to health can be overcomeby the wearing of face masks and protective clothing.

Orah The adoption of a fully enclosed pneumatic handlingsystem, although initially more expensive, often im-proves working conditions and reduces material loss aswell. Cleaner conditions improve morale, facilitateplant maintenance and reduce health hazards.

FIGURE 41

Portable pneumatic handling equipment

1. Combination vacuum/pressure system;conveying grain from ship intobagging hopper.

3. Vacuum-only system : transferring grainfrom ship into truck or rail wagon loadinghopper .

2. Combination vacuumipressure system;conveying from ship fo barge.

i--x’ j

i l-----i-/

4. Vacuuming grain from ship; loadinggrain by gravity into barge .

174

260. The travelling pneumatic elevator consists of arail-mounted gantry with a total enclosed superstruc-ture for housing the major items of equipment. Gener-ally, two units are housed in one gantry, and the usuallimit of unloading rates is about 200 tons per hour perunit. The unloading arms terminate in flexible intaketubes which allow very efficient cleanup of the hold.Material sucked through the nozzle is collected by cyc-lone-type separators and discharged on to the onwardconveying system, very often a belt conveyor.

261. There exist also waterborne versions of thetravelling pneumatic elevator. They are self-containedand self-propelled machines, with a throughput similarto that of the rail-mounted kind. They can be used fordischarging directly to shore storage or, in the case ofonward transport, to barges. They can also be arrangedto operate in reverse, from barge to vessel for export.

262. In addition, there are portable pneumaticunits on wheeled trailers which can be positioned onthe quay or aboard the vessel, as shown in figure 41.The handling rates of this light portable equipment arelow, usually about 50 tons per hour.

3. VERTICALCONVEYORS

263. The chain conveyor unloader (see figure 42) isa self-contained unit working on the en rnas~e principle.The free digging rate is generally limited to 150 tons perhour. The conveying chain is carried inside a rectangu-lar casing and its motion carries material from the hold.A second unit can be used as a connection to hinterlandtransport as the unit can be adapted for inclined andhorizontal conveying. The units are restricted to dry,friable materials that are compatible with direct contactwith moving parts. For intermittent use, it may be moreeconomical to employ this type of unit rather than thegrab ship unloader, in spite of its high maintenancecost.

264. The vertical screw conveyor is a full bladescrew contained in a tubular casing. The unit can beused at any angle from the horizontal to the vertical.Screw conveyors can efficiently deal with all fine pow-dered and granular materials, lumpy (provided thelumps do not exceed a specified size in relation to thescrew diameter), semi-liquid and fibrous materials.Free digging rates of up to 600 tons per hour have beenachieved. The throughput is restricted to the rate atwhich material can freely flow into the feed aperture. Aproprietary type of screw auger has an independentlydriven spiral around the feed intake to combat this feedproblem.

4. BUCKETELEVATORS

265. Bucket elevators are another alternative forhandling rates in the 1,00@5,000 tons per hour range.At present these continuous unloaders appear less effi-cient in terms of cost per ton unloaded than grabs,taking account of total capital expenditure and operat-ing costs. However, the free digging rates for theseunits will approach 5,000 tons per hour, while grabshave a maximum rate of 2,500 tons per hour. Develop-

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ments in this matter should be watched in view of thehigh theoretical handling rates.

266. One concept involves a continuously rotatingbucket wheel suspended from the luffing boom of thetravelling unloader. This bucket wheel digs up thematerial and feeds a continuous bucket elevator. Theweight of the structure plus the dynamic digging forcesrequire a heavier and more expensive quay than for theusual grab cranes.

267. An alternative approach uses a bucket chainelevator with the buckets acting as digging scoops. Asin the case of the wheel and elevator, the bucket eleva-tor is suspended from the luffing boom. A heavy found-ation is again required to absorb the digging forces, andmaintenance costs may be considerable. At smaller in-stallations, for example, those for the unloading of coaland phosphate from barges, purpose-built facilitiesutilizing the bucket chain elevator can be very useful.

FIGURE 42Chain emveyor unloader

5. SLURRY SYSTEM

268. Certain materials, such as iron ore, salt, baux-ite, heavy mineral sands and certain coals may be suit-able for transportation via the slurry method. Thismethod basically consists of making a slurry-water mix-ture with 70 per cent ore and 30 per cent water at amine site, and then pumping it aboard specially equip-ped mineral tankers. Excess water is decanted prior toship departure, leaving a concentrate with over 90 percent solids. At the discharge port, rotating water jets inthe bottom of the holds undercut and liquefy the oreconcentrate so that it can be pumped ashore. This sys-tem eliminates loading and discharge cranes, elaboratedocking arrangements and other facilities.

269. The slurry process is a clean one which mini-mizes material loss that occurs with other, dust-inducing ore-handling procedures. Decanted liquidduring the loading process may have to be returned to asettling pond to avoid pollution and to recover ultra-fine particles. The slurry form of the cargo makes iteconomic to locate the storage area some distance fromthe port area. The rate of discharge will be dependentupon the size of ship and the installed pumps, but forlarge vessels it will normally be 6,000-8,000 dry tonsper hour. Material can be loaded dry by conventionalsystems and unloaded using the slurry process.

6. SELF-DISCHARGING VESSELS

270. At the beginning of 1982, 56 per cent of thebulk carriers were equipped with gear for self-discharge, while only 12 per cent of the ore carrierswere so equipped. The average size of vessels so equip-ped was markedly smaller than that of vessels withoutgear. The gear usually consists of bucket cranes or der-ricks with a safe working load varying from 3 to 30 tons.

271. A limited number of carriers have been builtwhich utilize gravity reclaiming on to a belt, chain, orscrew conveyor in the bottom of the holds to feed anelevator system within the ship. These vessels requireonly a hopper and conveyor arrangement at the dis-charging terminal to transfer material from the ship’ssystem to the storage area.

H. Horizontal transport

272. Conveyors are the most extensively used pieceof equipment in dry bulk handling and reappear in avariety of forms in elevators, ship-loaders, packers andreclaimers, as well as purely for horizontal transport.For horizontal transport, unlimited distances cantheoretically be covered by conveyor, although trans-port economics will usually limit conveyor systems to afew kilometres before rail or road transport becomesmore appropriate.

273. The conveyor system layout has a major effecton the whole terminal area requirements, and on itsflexibility. The routes taken, and the choice betweenraised, ground-level or underground systems should begiven a similar degree of attention to the layout of aroad system in a built-up area. On long runs, design forease of maintenance is paramount.

274. The general adoption of the belt conveyor as amechanical carrier for bulk materials has been due toits inherent merits:

(a) Simplicity of construction;(b) Dependability and economy of upkeep;(c) Efficiency, with small driving power require-

ments.(d) Complete discharge of the material handled;(e) Adaptability.

The material is received directly on to the belt and iscarried with a minimum of friction and noise to its des-tination. There are no joints or other projections tobreak or wear, and abrasion or friction between thematerial and the belt exists only at transfer points.

275. The limited vertical angle at which belt con-veyors can carry materials necessitates a considerableamount of space to enable the material to be lifted tothe required height. The supporting structure for longconveyors also requires routine maintenance work suchas painting. These disadvantages have to be consid-ered.

276. Belt conveyors are either flat or troughed,with the former used for packaged material. Two flatbelt conveyors with their carrying surfaces located in avertical plane at an appropriate distance apart can forma “pinch” belt elevator suitable for the unloading andloading of bagged material. Peak rates of 4,000 bagsper hour have been achieved.

277. Developments have made possible the produc-tion of stronger and wider rubber belts with canvasplies. In addition to these belts with canvas plies, beltswith steel wire to increase tensile strength have beenproduced. In combination with improvements in theassociated belt idlers, belt conveyors are capable oftransferring several thousands of tons per hour.

278. The chain conveyor has a flighted chain whichmoves around inside a totally enclosed casing with adividing partition. Material can be introduced at anypoint in the top of the casing; it falls through an open-ing in the partition plate to the bottom of the casing,and is then conveyed by the chain until it reaches adischarge opening. The conveyor can be used up to anangle limited by the characteristics of the material. Anyfree-flowing material can be handled by this means,and the process is dust free. Grain is the most commonmaterial handled, and rates up to 500 tons per hour arepossible. For small port installations, in combinationwith chain-type unloaders, this type of equipment isvery useful.

279. The en masse conveyor is similar to the chainconveyor but is different in operating principle and hasa casing of smaller cross-section. The unit works on theprinciple that the friction between the material and thespecially designed chain is greater than the friction be-tween the material and the casing. The material shiftsas one body, en masse. This method permits vertical aswell as horizontal conveying, and multiple inlets andoutlets can be used. The construction can be madedust-tight. One disadvantage is that a certain amount ofproduct degradation occurs.

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280. Screw conveyors are a very compact form ofhandling with a totally enclosed casing, either U-shaped or tubular. The selection of the correct type ofscrew and trough cross section for the material to behandled is essential if maximum efficiency is to beobtained. Generally, capacities do not exceed 500 tonsper hour. The power required is much higher than forother conveyors. Provision has to be made to accom-modate end thrust due to the reactton of material alongthe casing. These conveyors can be inclined from thehorizontal.

281. The powder pump can be used for the onwardtransport of dry pulverized free-flowing materials.Capacities of up to 200 tons per hour at distances up to1,200 metres have been obtained. A high-speed screwfeeds material through a non-return valve into a cham-ber fed with compressed air which conveys the materialto the receiving vessel. Powders composed of fragileaggregates are unsuitable for this technique.

282. The fluidizing gravity conveyor can be used forhorizontal transport, particularly for powders. Theprinciple of the conveyor is that when air is passedupward through the material, the mass expands andbehaves as a fluid. The conveyor consists of a slopingtrough with a porous medium extending across itswidth. Powder fed into the conveyor flows freely downit.

283. The mono-cableway is the simplest form ofaerial ropeway and is the cheapest to install and main-tain. A single endless cable serves both to support andtransport the load, which is carried in buckets. A singlesection rarely exceeds 8 kilometres in length but mul-tiple sections can be used. Buckets are disengaged fromthe cable at transfer stations and are pushed or runautomatically on to the next section. At the terminalsthe loading and unloading can be either manual orautomatic. The maximum capacity is generally taken at150 tons per hour with a typical bucket capacity of 0.5tons.

284. The bi-cable system separates the supportingand hauling functions of the cables. Two parallel car-rying cables are provided on each side of the ropewaycentre line. Each cable is anchored at one end and isprovided with a tensioning device at the other. An end-less hauling cable is used to move the buckets sup-ported on the carrying cables. The relatively heavysingle loads which can be supported permit handlingrates of up to 500 tons per hour.

I. Weighing and sampling

285. Material must often be weighed immediatelyprior to loading or after unloading for payment pur-poses, or for checking against shipping documents. Asimple method is to weigh the material continuouslywhile it is being conveyed. and according to the type ofequipment used, varying degrees of accuracy areobtainable. Essentially, the loaded side of the belt iscarried over an independently supported section ofconveyor structure. The weight of material on this sec-tion oi the belt is instantaneously recorded. and in con-junction with the speed of the belt the quantity con-

veyed at any flow rate can be calculated automatically.Various forms of obtaining vveights give different de-grees of accuracy, and range from simple mechanical/electrical devices to electronic strain gauge units. Twostandard levels of accuracy may be provided: an accura-cy to within l-2 per cent of the actual weight, and anaccuracy to within 2-4 per cent. The degree of accuracyattained is dependent on the placing of the weigher,which is a skilled task.

286. Batch weighing methods are also employed,normally through the use of a weighing bin in conjunc-tion with a surge hopper. Material is temporarily di-verted to the hopper while the full bin is automaticallyweighed and dumped. Weighing towers are often incor-porated into the conveyor network, an inclined con-veyor being used to feed the top of the tower.

287. Sampling is sometimes a requtrement in atransfer of material, generally to satisfy the purchaserthat the material is in accordance with specifications.Any attempt to take a sample by hand could result inincorrect representation of a particular batch. It istherefore essential to take a series of samples automa-tically at timed intervals. In order to obtain a represen-tative sample from the whole series of primary samples,they can be mixed together and a further sample taken.This procedure can be repeated until a very representa-tive sample of the batch is obtained.

288. Several methods of obtaining samples areavailable according to the characteristics of the materialand the accuracy required. A usual type of samplerconsists of a scoop which is quickly swung through thematerial either on the belt or through the falling streamof material, and deposits its contents either into a sam-ple box or into a mixing hopper for further sampling.The decision as to the best method of sampling andtype of sampler to use should be left to the specialist.

J. Stackers and reclaimers

289. The stacker is a specialized machine designedfor the continuous stacking up of various kinds of bulkmaterials in storage areas, and comprises a tripper (seefigure 43) and a stacking-out conveyor. Material is dis-charged by means of a tripper which allows the stackerto be positioned anywhere along the whole length ofthe belt conveyor in the storage area. The material isthen fed on to the stacking-out conveyor carried in aboom which is capable of being slewed and/or der-ricked, or may be fixed. Figure 44 shows a typicalstacker arrangement. Sometimes, material can be dis-charged direct from the tripper to allow the area adjac-ent to the tripper to be used for storage. The capacitiesof stackers are constantly being increased. and outputsup to 6,000 tons per hour or more are possible, thelimiting factor normally being the rate of feed from theunloading equipment. Blending is achieved by the rightmode of stacking.

290. The modern reclaimer is a machine that cancontinuously reclaim and discharge the stored materialfrom the storage area. and consists of the reclaimingmechanism and the intermediate belt conveyor. Thereclaiming mechanism may be a revolving wheel on

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which buckets or gathering arms are attached. Reclaim-ers are high in efficiency provided that care is taken instockpile planning. Typical rated capacities of indi-vidual units vary from 1,000 to 3,000 tons per hour.Peak capacities must be used for designing conveyorsystems. There is a limitation on the order in whichpiles of different grades of material can be reclaimedaccording to their accessibility. It may also be necessaryto use a bulldozer to push the farthest parts of the pileinto positions accessible to the reclaimer arm. Large-capacity machines are very heavy and require substan-tial track foundations, so that the existing ground con-ditions could be the limiting factor.

291. Stacker reclaimers, as illustrated in figure 45,have the two functions of stacking and reclaiming in asingle unit. The belt conveyor on the boom travels inthe discharge direction with the reclaim wheel station-ary when discharging, and in the reverse direction withthe reclaim wheel in operation when reclaiming.

292. When the storage area is small, stacker re-claimers have proved to be extremely useful. In a smallarea, the installation of a separate stacker and a re-claimer will sometimes limit the working area of eachmachine and cause areas of inaccessible material. If theneed for stacking and reclaiming at the same time doesnot arise, for example, when for a single material the

FNXIRE 43

Principle of belt loop or tripper

FIGURE 44

Arrangement of stacker for feeding stockpiles

FIGURE 45

Typical stacker/reclaimer

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arriving flow can be routed direct to the ship-loader inaddition to the reclaimed flow, then it is recommendedthat a stacker/reclaimer should be used. with reducedinitial investment. On the other hand, if both opera-tions are required simultaneously, then separate-function machines are required.

293. An alternative to the bucket wheel stacker/reclaimer is a scraper/reclaimer, also known as a “back-stacker” reclaimer. Here the boom conveyor consists oftwo heavy-duty chains with flights of substantial pro-portions at regular intervals. For stacking, the boomconveyor flights scrape the material into the stack fromthe hopper feed. and for reclaiming, the chain conveyoris reversed and the material is scraped down the pileinto a trough to a normal conveyor. This system islower in maintenance costs and raises less dust. Themethod has been successfully used at a phosphate rockterminal.

294. A further alternative stacker/reclaimerarrangement, which in the past was used extensively, isthe overhead travelling transporter. Here a travellinggantry spans the storage area and contains a belt con-veyor at high level with travelling tripper. Alsomounted in the gantry are usually two travelling bucketelevators which can discharge on to the belt conveyor.

295. In the stacking operation, material from thestore yard conveyor is elevated to the gantry belt con-veyor for discharge direct to store by the travelling trip-per. For reclaim, the elevators, of open-frame con-struction, are lowered into the material which is re-claimed in the buckets and discharged on to the re-versed gantry conveyor. This discharges into the storeyard conveyor which is also reversed. The reclaim rateof the elevators is limited to about 500 tons per hourand considering the extensive steel-work required tocarry this equipment, with the subsequent high main-tenance costs, this type of unit has generally beensuperseded by the other forms of reclaiming.

296. There is another scraper/reclaimer type ofmachine which is usually installed in a storage building,although it can be used outside for materials that do notrequire weather protection. Capacities of up to 1,000tons per hour are available. In this unit the material pileis reclaimed by a scraper chain conveyor suspendedfrom a portal frame and pivoted at its lower end. Theframe is mounted on travelling bogies running on railsthroughout the whole length of the building. A beltconveyor in the terminal receives material from thepivoted end of the chain conveyor, whilst an additionalchain scraper is sometimes suspended from the otherleg of the portal frame to push the material into thepath of the main chain conveyor.

297. This approach has several advantages:

(a) Fully automatic operation of the machine is pos-sible, although it is usually operator controlled;

(b) Reclaiming is continuous;

(c) Reclaiming output is independent of the skill ofthe operator.

A disadvantage is that the substantial space requiredfor the plant causes loss of storage space inside thebuilding.

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298. The underground reclaim system can be usedfor either covered or open storage, and it is probablyone of the most common, although it has certain dis-advantages. It normally consists of one or more under-ground conveyors running the whole length of the stor-age and enclosed in tunnels, as shown in figure 46. Thesystem relies on gravity for the discharging of the ma-terial on to the underground conveyors. The shape ofthe tunnels is dictated by the method used for controll-ing the rate of discharge.

299. In one example of the system, there is a seriesof feed openings in the floor of the store, each fittedwith a chute and an adjustable cut-off gate. The flow ofmaterial through an opening can reach a speed of up to1.000 tons per hour, and the total reclaim rate will bedictated by the number of openings which it is feasibleto control. Normally, three or four openings can bedischarging at any one time on to each conveyor.

300. The main advantage of this system is that thecapital costs are relatively low, but these mav be out-weighed by the operating costs and the inefficiency ofthe reclaim. Each feed opening will be able to reclaimonly a limited amount of material, depending on itsangle of repose. Moreover. the rate of flow througheach feed opening will decrease throughout the dis-charge, requiring constant attention from an operatorto ensure that the total reclaim rate is maintained. As itis usually necessary to have more than one outlet inoperation at any one time, the extract rate will be de-pendent upon the skill of the operator, and some loss inoutput is inevitable. Another disadvantage is that it willnot be possible to empty the store completely withoutresort to the use of bulldozers, and this may not beacceptable when handling dusty or dangerous ma-terials. It can also be difficult to avoid severe dust levelsunderground and arduous working conditions for thefeed operators. Another important consideration to beborne in mind in the designing of underground reclaim-ing systems is that of drainage.

301. A form of extraction which overcomes theoperational disadvantages is the provision of a paddlewheel extractor to feed on to the belt conveyor. Here aspecially formed base to the store is required, havinghopper sides and a continuous slot running the wholelength of the store. The paddle wheel extractor, whichhas slowly revolving arms moving in a horizontal plane,is mounted in a travelling carriage which travels back-wards and forwards along the slot. Material is thereforecontinuously taken equally from the whole store, andthe whole operation can be carried out automatically byan operator from an isolated control room, which couldbe advantageous when dusty material is handled. Themain disadvantage of this system is in the cost of con-struction of the special slot opening, which can be high.

302. The dragline scraper has been used quite suc-cessfully in the past. but has been superseded to a largeextent by the mobile bulldozer and large-capacity front-end loading shovel. It is, however, still useful wherevery dusty materials are handled and the use of mobileequipment in an enclosed store would be undesirable.

303. The equipment consists of a winch house. gen-erally situated in a tower superstructure. which has areception hopper at its base, and a pair of hauling ropes

FIGURE 46

Underground reclaim with gravity feed to belt conveyor

Overhead stacking-Out conveyor

Bulk material

Covered store

U n d e r g r o u n d r e c l a i m

r Bei t conveyor

which extend from the tower to a travelling frame. Thisframe is power driven and moves around in an arc onthe outside of the stockpile. A travelling scoop,attached to the ropes, can be moved backwards andforwards across the stockpile. During its forward mo-tion, it moves material into the receiving hopper,whence it passes on to the conveying system.

304. For very small installations having an approp-riately sized storage area adjacent to the quayside or toa reclaim conveyor system, it may be convenient to usea front-end loader and a mobile belt conveyor having asuitab!y sized feed hopper. In some installations, asmall feeder conveyor below the surface must be usedwith a wide ground-level hopper having an open sidethrough which material may be directly pushed. With afront-end loader, capacities up to 100 tons per hour arewithin the capabilities of each driver. The mobile beltconveyors can also be used for direct loading intobarges and lighters from tipping trucks. The rate ofloading is determined by the vehicle tipping speeds.

305. A scraper is standard equipment used in civilengineering for site preparation, and for the open pitworking of certain minerals. It has been used very suc-

Stacking

-L-1

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sizz

cessfully for emergency stock reclamation, when amachine with a capacity of up to 20 cubic metres can beused. When the bowl is full, the clam-shell gate isclosed and the bowl raised clear of the ground; themachine then travels to the discharge point. It is onlypossible to discharge into a suitably sized ground hop-per, which will add to the civil engineering capital costs.This type of reclaim can be used only when degradationof the material, due to the heavy machine travellingover the storage area, is acceptable.

K. Storage

306. The availability of land for the stockpile is lim-ited either by the natural conditions or by the cost ofacquisition. The stockpile must therefore be planned sothat a maximum amount of material can be stored in aminimum area. The volume of material which can bestored in a given area will depend, not only on thebearing capacity of the ground and the characteristicsof the material but also on the outreach and height ofstackers and reclaimers. The function of the stockpile isto enable transportation facilities with different times

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and rates of working to function independently of eachother, so as to avoid delays caused by one facility hav-ing to wait for another.

307. The most common form of bulk storage is thewind-row arrangement (see figure 47). where materialis arranged in an elongated pile, the width of which isdetermined by the height of discharge and the angle ofrepose of the material. On smaller sites. a circular pilemay he arranged, with stacking out and reclaim from acentral rotating stacker/reclaimer. The storage areamay he open to the elements or completely covered,according to the material and the prevailing weather.

308. For material affected by weather, a coveredstore. normally a portal-framed structure spanning thewidth of the pile and extending for the whole length, isused. Feed-in is generally from a high belt conveyorsituated along the apex of the building and reclaim is bymeans either of a scraper/reclaimer or of an under-ground conveyor. When dusty materials are beinghandled, it may not be possible to reclaim with a scrap-er/reclaimer at the same time that material is being fedinto the store. The two options are then either to erecta second storage building. or to use an undergroundreclaim system.

309. When unloading a vessel it may be necessaryto use road vehicles or rail trucks for onward transport.In this case it may be convenient to use a storage bun-ker or truck silo in conjunction with the open storage.The bunker takes the form of an elevated store oflimited quantity that can be fed at the same time as themain flow to the stockpile. The onward loading oftransport vehicles is carried out from bottom-openingdoors. Control is usually effected from raised platformsgiving an unobstructed view of the loading operarionand of the traffic movements. Bunkers may be con-structed from reinforced concrete or structural steeland plating, and arranged to be fed from overhead con-veyor systems or pneumatically.

310. When storage bunkers are empty, material en-tering could have a considerable distance of free fall,which would result in segregation and in degradation offriable materials. One device to prevent this degrada-tion is a specially designed chute in the form of a spiralwhich arrests the fall of material by friction in the chutesides. Segregation occurs when particles of a well-mixed material. being delivered from a single point. fallon to the cone of material. Fine particles tend to lodgein gaps, while large particles tend to roll down the sur-face of the cone and collect near the walls. Where seg-regation is to be avoided. care must be taken to ensurethat material is withdrawn evenly from the whole cross-sectional area of the bunker. This can be achievedthrough careful design by specialists.

311. A silo may be a single unit or a multiple unit inwhich various grades of material may be stored. Silosare generally used for the storage of grain and animalfeeds where provision must be made for sealing againstthe ingress of moisture and \fermin. Construction ma-terials used can be reinforced concrete or steel, inwhich case the steel wall plates should preferably becoated with vitreous enamel to provide a surface whichis virtually impervious to corrosion. This protection isimportant. as a silo unit in close proximity to the sea

would be adversely affected by salt sea spray. Inter-nally, any corrosion would adversely affect the qualityof grain. The silo is fed from an overhead system anddischarged through bottom doors.

312. The tote bin system has been developed inrecent years for the handling of minor bulk cargoes.especially where a sealed container is required. The binis both a shipping container and an intermediate stor-age unit which becomes a discharge hopper whenmounted on special tippmg equipment. Thus the ma-terial remains in a single container throughout the pro-cess of transportation.

313. The usual material used for the bin construc-tion is aluminium, which is light in weight, resistant tocorrosion and capable of being stacked. Unfortunately.as in the case of all bulk bins. the return journey of theempty bin adds consIderably to the cost of transporta-tion, and this becomes a serious constraint for longjourneys and for export materials. If the bin can bereduced in volume for the return journey, this dis-advantage is minimized. Alternatively. a cheap throw-away container can be used.

314. A surge hopper is often necessary to act astemporary storage during a certain phase of a con-veying operation. For example, during a loading opera-tion a ship-loader will need to be moved from hatch tohatch. While it moves, the material flow from the ship-loader must be stopped to prevent spillage on the deckof the vessel. The conveyor system from the stockpilecan be kept in motion if the material flow to the jettyconveyor is bypassed into a surge hopper.

315. When the ship-loader is in position again, theship-loader and jetty conveyor are restarted, takingmaterial from the approach conveyor plus the materialtemporarily stored in the surge hopper. The ship-loaderand the jetty conveyor are sized to suit this increasedflow of material.

316. This method can give considerable improve-ments in throughput, but for smaller throughputs theinstallation of a surge hopper may not be justified. Thesize of the hopper depends on the rate at which ma-terial flows along the approach conveyor and the timetaken for the ship-loader to travel between the hatchesfurthest apart.

L. Vehicle reception

317. There are four main ways of discharging bulkcargo from rail wagons:

(a) Bottom discharge;

(b) Rotary tipping;

(c) End tipping;

(d) Pneumatic discharge.

In the first three methods, the material is dischargedinto a hopper which is emptied via a transfer conveyor.Bottom-discharge wagons are fitted with bottom doorswhich open to empty the vehicle. For the rotary andend-tipping facilities the rail car is physically rotated ortipped to discharge the wagon. With the rotary tipper,the rail wagons do not have to be uncoupled if they arefitted with rotating couples.

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FIGURE 4 7Export port showing arrangement of wind-row stockpiles

318. For powdery free-flowing materials, a com-bination of compressed air and gravity can be used todischarge the wagon. The wagon consists of a pressurevessel and is discharged via hoses to the receiving store.

319. Road trucks have the same method of dis-charge as rail, but can often be self-tipping. High-capacity tippers have a gross weight of over 32 tons,while smaller tippers have gross weights of 24 and 16tons. Trucks with pressure vessels for pneumatic dis-charge can be fitted with a diesel-engined blower unitto make deliveries independent of an external air sup-ply. Self-tipper trucks can discharge directly to stock-piles via a mobile belt conveyor with a hopper.

M. Stand-by facilities

320. The high cost of the vessel’s time makes itessential that equipment should be available at all timeswhile the vessel is alongside the jetty. A plant break-down during unloading/loading operations can result inhigh demurrage payments. Preventive maintenance willgo a long way to reduce this down-time, but stoppagesthrough plant breakdown will still occur. In addition toa skilled maintenance force to repair the fault quickly,provision must be made for the duplication of certainconveyors and for the necessary rerouting of materialflows. The provision of other stand-by equipment forunloading/loading should also be considered. This

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could take several forms; for example, either two re-claimers can be arranged to cover one stockpile, or theuse of high-capacity mobile front-end loaders can beresorted to. Stand-by mobile front-end loaders can alsosupplement the normal rate of reclaim during seasonalpeaks, using emergency reclaim hoppers which aremounted on tracks alongside the reclaim conveyors.

321. The grab bucket has high reliability, with onlyfew, components subject to wear, and any necessaryrepairs to the digging lips, shells and bearings can easilybe effected at low cost in a workshop. Several sets ofgrab buckets for a single bulk unloader are normallypurchased so that the correct type is available for eachof the different bulk commodities and vessels, and re-serve buckets are available for each commodity. Wheretwo unloaders are in operation, one machine can con-tinue operatmg during the short period needed tochange the bucket on the other. Adequate provision forstorage and for transportation of grabs to the work-shops for repair should be provided in the jetty design.

N. Environmental considerations

322. Pollution prevention is a major cost item andat the outset of any scheme it will be necessary first toestablish an environmental policy. It will be necessaryfor the appropriate authority to specify the importanceit attaches to the local environment. and how muchextra it is prepared to pay to maintain it. In order totake a decision. the planner will need to prepare astatement on the probable effects of the installation onthe local environment in the absence of any specialprecautions. In addition, a study of working conditionswithin the terminal will have to be made. At this stage,experts should be called in and proper specificationsagreed upon satisfying the policy laid down.

323. The characteristics of the material handledmay be that it is very dusty. or dangerous to health, oreven liable to form explosive mixtures with air or mois-ture. Several problems arise with respect to dust sup-pression or extraction. First, the degree of pollutiontolerated must be clearly specified, the minimum re-quirements being stated quantitatively, for example,that the area within a specified distance from the instal-lation should not contain more than a specific numberof grams of material per cubic metre. Imprecise state-ments such as “nearly dustless” or “to the satisfactionof the engineer” should be avoided. A large amount ofdust will emanate from a poorly maintained plant; thussimplicity of design and easy maintenance should besought when a choice of equipment is being made.

324. A study should be made of equipment actuallyin use for the handling of similar material in order todetermine the environmental effects. For example,many attempts have been made to seal the receivinghopper of a grab unloader effectively when material isbeing discharged from the grab into the hopper. Theuse of an air curtain will prevent dust spreading ondischarge, but it should be remembered that the grabhas to pass through this curtain to its discharge positionand that a certain amount of material will be blown offthe surface in the process. A more effective method

may be to put the hopper into a chamber sealed withrubber curtains.

325. Often the prevailing wind will assist in pre-venting dust pollution by blowing the dust out to sea-acondition that may be acceptable. However, a port in-stallation sited upwind of a community could find itselfin serious trouble at times of high wind when a dustyproduct is being handled without effective dust control.Operations might have to cease at such times, withresultant high costs for ship delay>. For certain cargoes,a water spray system may be used to prevent dust, or anenclosed storage area may he used to contain it.

326. Attention must be paid to the risk of corro-sion, and all structures should be adequately treated toprotect them from the effects of the moist, salt-ladenatmosphere and of the materials being handled.Specialist advice should be obtained as experience canbe drawn on from existing installations. Should protec-tive sheeting be fitted to structures, this should receivethe same consideration. High daytime temperatures inhot climates produce extensive condensation during thehours of darkness. This is especially apparent on theinsides of silos.

327. Wind can also blow dusty material off a belt ifit is not protected by wind boards, a simple housing, ora totally enclosed gantry. In addition, wind forces cancause the belt to track very badly and, under extremeconditions, to lift off the idlers completely, especiallywhen unloaded.

328. In the case of ship-loaders and unloaders, fullaccount must be taken of needs for operating underwind conditions. The power applied to each operationmust be adopted accordingly. especially when loadersor unloaders are being moved along the quay. Dueallowance must he made for the opposing wind forceswhen the equipment is travelling into wind and, like-wise, when it is travelling with the wind, due allowancemust be made for the wind in determining the brakingforce required to arrest travel within the specified dis-tance. Under storm wind conditions, special anchoringpositions must be provided where the equipment can bepositively secured.

0. Planning tasks

329. The argument is sometimes advanced that theplanning of a bulk cargo port terminal should be doneentirely by the industry planners for the bulk commod-ity concerned, as part of the total physical distributionsystem from, say, up-country mine to overseas cus-tomer. A coherent overall plan, based on through-transport economic principles, should certainly bedrawn up by the industry planners at the appropriatetime. There are often large gains to be made by co-ordinating the production rate, land transport, portstockpiling and handling, and maritime transport.However, the work done by the industry sector plannerdoes not relieve the port management of the need toplan and control the main design parameters of all drybulk cargo installations within the port area.

330. The port planner will need to know at an earlystage of the planning the genera1 implications for landand water areas of long-term developments in the

183

sphere of dry bulk cargo transport. Also, during thestage of the preparation of detailed designs by the in-dustry sector planner, there is a need for close consulta-tion with the port planner to ensure that the main de-sign parameters of the terminal are correct.

331. In addition, there are often common users of adry bulk cargo terminal, and as far as they are con-cerned the design responsibility is clearly that of theport authority. There will be common parts of an instal-lation that are used by several different bulk cargo car-riers, for commodities that are to a varying extent com-patible. It will be necessary for compromises to bereached between the demands of a number of differentusers.

332. For these reasons the port planner shouldcarry out his own calculations for each of the followingpoints, procedures for which are given in this hand-book:

(a) The effective hourly capacity of each handlinginstallation and the combined capacities of all the hand-ling installations;

(b) The number of berths and the number of ship-loaders at each berth;

(c) The capacity and location of surge storage instal-lations, stores and stockpiles;

(d) The capacity of the inland transport vehicle fleet.

333. Ideally, the industry sector planner should beable to give the port the specifications of the service theport should provide, and a target port cost per ton,based, in the case of exports, on the acceptable f.o.b.export selling price. Where the service specificationsand a target cost are not provided, the planner mayhave to make broad estimates of the acceptable levelsof cost and ship service.

334. From the point of view of port interests, onehigh-capacity dry bulk cargo terminal is preferable totwo or more terminals with moderate yearly capacity.When growth in exports seems possible but uncertain,it may be advisable to start with modest and not tooexpensive facilities. Allowance should, however, bemade for the possibility of installing additional ship-loaders and higher-capacity conveyors and increasingthe stockpile area, if necessary, at a later stage, withoutany serious interruption of operations. With carefulplanning, expansion in this way should prove moreeconomical than the construction of a second terminalfor the same kind of material.

335. The whole terminal operation must be system-atically set out showing the rate of tonnage per hour foreach piece of equipment, and for each situation thatmay arise during the sequence of loading or discharg-ing. Special buffer arrangements will be required whenone part of the installation has to be halted.

336. Often there will be alternative operatingmodes and routes for the flow of the commodity. Thematching of flows will need to be calculated for eachof these modes. The design must be carried out by aspecialist for the installation concerned, but the portplanner can however check on the part of the designconcerning the ship operation by using the followingplanning charts.

337. The ship-handling capacity of the terminal isdetermined by a joint analysis of the number of berthsand the number and handling rates of the ship-loadersor discharging installations at each berth. The handlingrates of ship-loaders are governed largely by the re-claiming rate. Planning charts I and II, illustrated infigures 48 and 49, should be used for this analysis.Where seasonal effects are important, special attentionmust be given to the investment advantages and dis-advantages involved, as discussed in part one, chapterII, on planning principles.

338. The planning charts for the dry bulk cargo ter-minal have been developed to assist the port planner inhis economic analysis of the effects of various handlingrates on ship turn-round time. In addition to the econ-omics, the planner is also interested in the service timesthat various sizes of shipment will entail. These chartscan be used for either an import or an export dry bulkcargo terminal.

339. As has already been made clear, the produc-tivity of each ship-loader or unloader varies accordingto the characteristics of the ship and the cargo, and theposition of the cargo in the ship. Manufacturers oftenpublish rated capacities for a particular commoditywhich are based on near-optimum operating condi-tions. However, to obtain the effective hourly capacitywhen working, an efficiency factor covering the totalship working time (through-ship efficiency factor)should be applied. This factor should be determined bya specialist, but as a rough check it could be taken asnot more than 0.5 for unloading and 0.7 for loading.

340. The law of diminishing returns applies as re-gards the number of ship-loaders or unloaders whichcan work one ship. That is to say, doubling the numberof facilities at a berth will not necessarily double thethroughput of the berth. For the purposes of the plan-ning chart, the following throughput factors have beenassumed for two., three, four and five ship-loaders/un-loaders per berth respectively: 1.75; 2.25; 2.60; and2.85.

341. Dry bulk cargo terminal planning charts I andII are used in the same way as break-bulk cargo ter-minal planning charts I and II. The planner needs thefollowing basic information in order to be able to utilizethese charts: ship-loader/unloader rated capacities; av-erage shipment size; number of ships per year; averageship cost per day; and number of berth commissiondays per year.

342. The planner enters planning chart I with thefigure indicating the rated capacity; he then draws avertical line to make a turning-point where it meets thethrough-ship efficiency factor. He then moves horizon-tally to the left to the next turning-point with theappropriate line for the number of ship-loadersiunload-ers employed per berth. He descends again to the stan-dard number of ship operating hours per day, thenmoves horizontally to the right to the turning-pointwith the curve indicating average shipment size andfinally draws a vertical line up to the average berth timefor individual ships. A typical two-hour delay for berth-ing and deberthing ships has been added to this averagetime. When the actual delay differs from this, the aver-age berth time can be adjusted accordingly.

1 8 4

185

-.

:-

186

343. The turning-points on the axes give the plan-ner the following information: effective capacity ofeach ship-loader or unloader; through-ship gross load-ing or unloading rate: through-ship net loading or un-loading rate (which is equivalent to the gross rate if theberth is worked 24 hours per day); and average berthtime for individual ships. The through-ship net rate is akey figure in describing the productivity of a bulkberth.

344. For planning chart II. the planner starts withthe average ship berth time. A similar method is usedas for planning chart I. with the following turning-points: number of ships per year; number of terminalcommission days per year; number of berths; and theaverage daily ship cost while at port. The number ofterminal commission days per year is the sum of thenumber of commission days for each berth. For eachset of turning-points, the mtersections of the trajectoryand the axes give the planner the following informa-tion: annual berth-day requirement; berth utilization;ship time at port; and annual ship cost while at port.

345. The relationship between berth occupancy andship time at port is based on queueing theory. TheErlang 2 distribution was used for both the service timedistribution and the inter-arrival time distribution. Un-like break-bulk cargo terminals, there is a tendency, inthe case of dry bulk cargo terminals, towards somescheduling of arrivals, and for this reason the slightlysmoothed Erlang 2 arrival distribution has beenassumed rather than the Erlang 1 (i.e. negative ex-ponential) distribution. These distributions are discus-sed in annex II, section D.

346. The first chart can also be used by the plannerto determine the best combination of rated capacity,number of facilities and daily operating period neces-sary for a specified berth time for a particular shipmentsize. When a suitable combination has been found, theplanner can then use the second chart to select thenumber of berths necessary for the forecast annualthroughput. The approximate number of ships per yearis calculated by dividing the annual throughput forecastby the average shipment size. In order to determine theoptimum number of berths, estimates must be made oftotal ship times at port with different numbers ofberths. The optimum number of berths will be the num-ber at which the total of berth costs and ship costs islowest.

347. The export stockpile is needed as a buffer be-tween the delivery system to the terminal and the ship-loading system. The delivery system’s arrival distribu-tion is dependent on the production rate and the inlandtransport system. Generally, the rate of arrival is muchslower than the ship-loading rate, and the economicsare such that the ship should not be kept waiting.Therefore, when a ship arrives, the quantity for ship-ment should be in port storage.

348. With regard to the import stockpile, the con-verse is true. the hinterland transport system operatingat a much slower rate than the ship unloading rate. Thestockpile should never be so large that a ship is pre-vented from unloading, nor so small that inland distri-bution is disrupted and the industries using the bulkcommodities are affected.

349. The planner is faced with the problem ofselecting an inventory level and storage capacity whichwill minimize costs by acting as a buffer between thevariable demand and supply. If the level falls too low,the situation will occur where either the ship or theindustrial zone is kept waiting for cargo. If the storagecapacity is insufficient. the system supplying cargo tothe stockpile-either the hinterland transport or theshipwill have to wait. As against these waiting costs,there are the capital and operating expenditures in-volved in creating and maintaining the stockpile.

350. The area required for the stockpiles is depen-dent on the following factors: shipload size; ship arrivaldistribution; hinterland transport distribution; andship-loading and unloading rates. For export cargo, thehinterland transport requirement depends on produc-tion rates. The above factors are stochastic and thusthere is no deterministic solution to the question of theappropriate inventory level and storage capacity. Fig-ure 50 shows a typical variation in inventory level overa period of time.

351. Simulation or Monte Carlo methods, as de-scribed in annex II. can be used to evaluate the econ-omics of various stockpile policies. However, informa-tion regarding the above-mentioned variables will oftenbe limited. Certain assumptions have therefore beenmade (see the annex to this chapter). The curves basedon these assumptions, which are given in figure 51,show the average and maximum stockpile levels whichreduce the probability of the disruption of operationsfor ships, production areas or industrial zones to lessthan 1 per cent. The full line curves are annotated withthe proposed annual throughput of the terminal. Theygive a relationship between the average shipload sizeon the horizontal scale and the stockpile capacity on thevertical scale. The cost of holding such an inventorylevel and developing the necessary capacity may begreater than the cost of the disruptions.

352. The charts should be used with some cautionowing to the simplicity of the model, but they shouldgive a good first approximation to the stockpile require-ments. Thus, for a terminal handling 1 million tons peryear with ships carrying an average of 20,000 tons, themaximum capacity of the stockpile should be 140,000tons and the average amount of cargo held should be75,000 tons. These figures must be increased by theamount of the dead stock, which is the residual materialnot loaded on to the ship in order to prevent ship delaysarising from the slow process of clearing up the stock-pile. The process of clearing up which is done duringidle periods must be completed within a given time-limit.

353. Bulk commodities must often be segregatedaccording to their properties. For example, with regardto imports, each stockpile area must be of sufficient sizeto accommodate at least a full shipload from eachsource. One iron-ore importing terminal has made eachstockpile area 50 per cent larger than the capacity of thelargest ship used. This allows the accommodation of asubsequent shipload of similar ore before the earliershipload has been fully used up. The need for segrega-tion is thus a factor to be taken into consideration in theplanning of bulk cargo stockpiles.

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FIGURE 50

Typical variation in dry bulk cargo terminal inventory level

I

A. EXPORT STOCKPILE2i ---- ---- ____52 - -----E52hEl

---- -----_

B. IMPORT STOCKPILE

Maximum

T I M E

--.Jlh- ---B Time berth occupied

TIMIIE

.-- - - - M e a n

t- - - - - - Minimum

FIGURE 51

Guidelines for export stockpile dimensioning as a function of annual throughput and average shipload

FIGURE 52

Stockpile layouts

-\

f

354. If a storage facility at the terminal is plannedto overcome seasonal or market fluctuations by provid-ing for a continuous supply in spite of a non-continuousconsumption. or vice versa, large areas must be setaside. Obviously a high degree of mechanization of thewhole storage area in this case is uneconomical, and anappropriate design must be selected.

355. Upon determining the stockpile requirementsin tonnes. the planner must then determine the layoutand the area required to store this tonnage. Possiblelayouts are shown in figure 52 where: cu=angle of re-pose, h=height, I=length and b=base. The height andbase dimensions of the stockpile are determined by thecharacteristics of the material, the bearing capacity of

the ground and the reach of the stacker/reclaimer. Withthese dimensions the planner may use the stockpiledimensioning dry bulk cargo terminal planning chartIII, shown in figure 53.

356. The figure for the base or width of the stock-pile is the starting-point for the use of the chart. Theplanner descends to the angle of repose of the commod-ity, which is the angle between a horizontal surface andthe cone slope obtained when bulk cargo is emptied onto this surface. Angles of repose for various commod-ities are given in annex I. He moves to the right todetermine the maximum height to which the materialcan be piled, and to the left to determine the maximumcross-sectional area. The ratio of actual height to max-imum height determines the next turning-point. Theplanner descends from this point to the line indicatingthe length of the stockpile. The cross-sectional area ofthe stockpile is given by the intersection of this pathwith the axes. From the appropriate line he moves tothe right to the stowage factor, and then rises to thehorizontal indicating the capacity of the stockpile. For agiven base and height, the length can be varied to givedifferent stockpile capacities.

357. The task of planning the land transport fleet issimple, but it should never be omitted in forward plan-ning lest the often daunting size of the transport fleetneeded is overlooked. Three elements regarding whichmistakes in planning are likely to occur are the fol-lowing:

(n) The number of transport working days per year:

(b) The average number of trips per day;

(c) The number of road vehicles out of action formaintenance and repair.

358. With these cautions in mind, the method ofcalculation for a single commodity is straightforwardand a numerical example is shown in table 7. Here. theimplications of carrying the whole output either by roador by rail are given first, followed by a suggestion for asharing of the load. Reserve capacity is needed, notonly for maintenance purposes, but also to make itpossible to augment the vehicle fleet temporarily tocope with peak demands.

359. A complication occurs when several differentcommodities have to be transported by the same facili-ties. For example, an aluminium smelter may require

TABLE 7

Transport fleet planning for a single commodity

*mu*, ,ermmol‘hiOi,pbpU~

oo!lne.~~

All by road:2 000 000

All by rail:2 000 000

Suggested combinatmn:20 per cent by road

400 000

80 per cent by rail1 600 000

A lml&vDdY number of

WhlCk m&sdenumd per da> veebic,r flrei Illd

3 0 0 3 100, plus maintenance reserve = 110 trucks

3 0 3 1 303, m 5 trains of approximately 60 wagons each

60 3 20 plus reserve 24 trucks=

2 4 2 1 242, in 4 trams of approximately 60 wagons each

189

w I

190

TABLE 8

Transport fleet planning for multiple commociities

Annual smelter rhroughpulOutput : 120 000 tonnes aluminium metal;Input 240 000 tonnes alumina;

72 000 mmes petroleum coke.

Alummium metal 2 310 5 4 6 2 2 2 21 4 5+

Proposal 7 tractor/trailer umts. mcludmg reserve.

the import of 1,500 tons of petroleum coke for each5,000 tons of alumina imported, and it may then exportvia the same route 2,500 tons of aluminium metal. Insuch a case it would be normal to plan the transport ofthese three commodities jointly. In a rail operation itmight be possible to introduce a closed-loop train sys-tem. In a road operation it might be possible to co-ordinate the haulage of different commodities using acommon vehicle fleet. In the aluminium smelter exam-ple, since there is no prospect of balancing the importand export flows. and since, further, the type of vehicle

suitable for alumina and coke is quite unsuitable foraluminium bars and ingots, it would be appropriate tointroduce two separate transport systems and toleratethe poor return-load operation.

360. Table 8 gives a numerical example for thissolution. An additional feature as compared with table7 is that the common alumina and coke fleet needs tobe scheduled with, say, four days of hauling aluminaand then one day of hauling coke. Such a schedule willbe dictated by, and will in turn dictate, the buffer stock

TABLE 9

Check-list of questions for planning dry bulk terminals

1. Has there been a search for the best site for the ternunal alongthe coasthne, without hmiting the search to existmg port bound-arm? The place of ongm or point of processing of the materialmay be more nnportant than the location of an existing portorganization.

2. Has a coherent overall plan for the commodity been prepared?There are often large gams to be made by deslgmng an integratedtransporr se~wce which mcorporates.

(a) ProductIon and processing of materials;(b) Land transport;(c) Part stockpiling and handling;(d) Maritime transport.

3 . Has the industry planner specified the lrvrl of service that theterminal IS expected to give, and a target port cost per tonrelated to the commodity selling price?

4. Will the terminal be dedicated to a single user, or wdl there beseveral users on B common-user basis?

5 WIN the terminal be used for a single commodity (wdl the com-modity require segregation by different grades) or will parts ofthe installation be used in common with other commodities?In the latter case, have compatibility questions been dealtwith?

6. Have facilities for long-term growth been considered? Eton-omically it 1s preferable to have one high-capacity terrmnalrather than two low-capaaty termmals. Thus expansmn must beconsidered in terms of:(a) Installing additional ship-loaders;(b) Installing higher-capacity conveyors.(c) Increasing the stockpile area.

7 . Has the tsrmmal been planned for specific ships m the case ofan integrated system. or for a range of ships in the case of a

common-user terminal? The ship characteristics to consider are:(a) Operatmg draught;(b) Beam and length;(c) Type of slxp (bulk, combined, general cargo);(d) Shape of hold and hatch opening.

8 . Has an economic criterion been used for the ship handhng rateand the resultmg berth occupancy? The high cost of ship’s timeresults in high rates with low berth occupancy (calculations canbe checked on the planning charts).

9 Has the cost and suitability of an offshore berthing point beenconsidered versus the cost of dredgmg?

10. Has pollutmn of all types--dust, explosive mixtures, healthrisks-been considered and related to the prevading wind?

11. Has the pollution prevention scheme been based on a clearspecification (quant%ttively precise) of what is to be permltted?

1 2 . Has a study of workmg conditions on the terminal been made?There may be lobs in adverse locations whxh require specialprowsions.

1 3 Have the local conditions of a prevailing hot climate and salt-laden atmosphere been considered with regard to corrosion ofstructures and night-time condensation”

1 4 . Have all wnd conditions been allowed for, including anchoringof ship-loaders during storms?

15. Has an unambiguous rated capacity for an unloader (loader)been specified, for example. the rate which can be sustained forone hour when unloading (loadmg) from the centre-hne of thevessel horizontally and from the mean low water level vertic-ally?

16. Have the above considerations been based on actual experiencewth a similar type of installation rather than manufacturers’figures’!

191

capacity both at the port and at the smelter, and will beinfluenced by the economies involved in cleaning ve-hicles and changing common reception/delivery instal-lations from one commodity to the other.

361. To conclude this section on planning tasks, acheck-list of the main questions that the planner of adry bulk terminal must answer are given in table 9.

P. Major bulk commodities

1. 1~0~ ORE

362. Iron ore is the most important dry bulk com-modity in international sea-borne trade, representing in1980 16 per cent of total dry cargo trade (dry bulk aswell as general cargo). Iron ore includes ores such asmagnetite, hematite, limonite, siderite and roasted ironpyrites. It is seldom sold in the form in which it isextracted from the ground, normally being processed toimprove its characteristics or to increase its iron con-tent. Washing, grinding, screening, agglomerating pro-cesses (pelletizing, sintering, briquetting) and variousmethods of concentration are used for this purpose.Traditionally the separation of waste from the ore tookplace at the consumer end. However, this is changing,

FIGURE 54Iron-ore loading berths: maximum acceptable ship sizes

and the trend is towards taking steps at the producingend to increase the iron content of the ore.

363. The ore shipped has a stowage factor whichvaries between 0.3 and 0.8 cubic metres per tonne. Ironore is always transported in bulk and in full shiploads.Over the past decade, iron ore trade has been the sub-ject of considerable competition between alternativesuppliers, characterized by increasing distance betweensources and markets and the employment of the largestpossible carriers. With the increased distances, thequick turn-round of specialized ore carriers in ports nolonger compensated for the loss of time involved inlengthy ballast voyages. Thus, combined carriers offer-ing greater versatility in the employment of vesselshave been replacing the specialized ore carriers. In1979, 95 per cent of total iron ore shipments were car-ried by bulk carriers and combined carriers of over18,000 dwt, and 81 per cent in vessels of over60,000 dwt.

364. While there are no major discharging termin-als for iron ore in the developing countries, there areseveral loading terminals. For loading terminals, figure54 illustrates the distribution of berths relative to vesselsize, and its evolution with time. Generally, iron oreports serve as transfer terminals linking two modes oftransportation, and hence some stockpiling capacity isalmost always necessary to provide a surge capabilitybetween the more or less continuous overland move-ment and the intermittent ocean shipments. Figure 55shows a typical iron ore export terminal.365. Ore varies both in the nature of its constituents

other than iron and in the percentage of its iron con-tent. Iron ores are generally dusty and, although thereis a variation in dust pollution between the variousqualities and particle sizes, it is normally necessary toprovide dust extraction equipment and to consider ter-minal siting carefully. Because of the importance ofproducing steel of a suitable grade for a particular pur-pose, control is necessary over the blending of ores forblast furnaces. This necessitates the segregation of oresaccording to their properties. The density of iron orelimits the stacking height because of the limits of theload-bearing capacity of the ground. The angle of re-pose is normally less than 40 degrees.

2. GRAIN

366. In 1980 the sea-borne trade in grain was 198million tonnes, forming 10 per cent of total dry cargo

Material flow in ore export port at Nouadhibou, Mauritania

Ship-loading plan1(3,000 tonnes per hour)

192

TABLE 10

Sizes of ship employed in the grain trade

(Percemg~ of world sea-borne wade m gram)

Under I8 MI . . . . . . . . . 4 1 37 2Y 32 33 21 15 IO 11 1018-2s CKIO . . . . . . . . . . . 21 1x 20 18 15 13 11 13 10 102%40 000 .... ....... 27 32 3 6 37 36 35 35 3h 3h 344G-60 000 ................. 10 12 14 12 I1 1s 18 18 18 1760 0 0 0 + 1 1 I 1 5 Ih 21 2 3 2 5 29

shipments. These shipments were composed of wheat(79.2 million tonnes), maize (70.7), soya beans (26.9),barley/oats/rye (11.4) and sorghum (9.Y). In addition,some 10 million tonnes of rice were shipped in the shortsea trade. These grains have different densities, whichmeans different stowage and handling requirements.Furthermore, grain is a perishable commodity whichrequires proper ventilation and protection from theweather and pests during shipment and storage.

367. Sea-borne grain shipments come under twoheadings: commercial shipments and international aidshipments. Commercial shipments take place, in orderof importance, to Western Europe, Japan, the USSRand Eastern Europe from the main exporters, theUnited States, Canada and Australia.

368. In the grain trade, variations in climatic condi-tions result in large variations in supply and demand,with consequent fluctuations in transportation require-ments. Without the incentive of a sustained level ofimport demand within each country, and consideringthe high capital cost of facilities, port development forvessels carrying grain is often not feasible. One solutionis the use of mobile pneumatic equipment. Also, thetrend to standardization of vessel type and size hasbeen less pronounced than in the other bulk cargotrades. Many types of vessel are employed, rangingfrom small traditional ‘tween-deckers through variousbulk carrier types and sizes, into the smaller ranges ofcombined carriers and even some small tankers. Whilethe size of the average carrier has increased over theyears, with the transfer to the trade of combined car-riers of approximately 150,000 dwti3, the ships mostcommonly used are bulk carriers, the majority being inthe 25,OOC~40,000 dwt range. Ships in this range builtduring the period 1971-75 were, on the average, 182metres in length, 25.3 metres in maximum breadth and10.8 metres in summer draught. The trend towards theuse of larger vessels is shown in table 10.

369. An example of a grain terminal is theone owned and operated by the Port Authority ofMarseilles for common users, which is primarily usedfor discharging cereals from vessels. A plan of the ter-minal is shown in figure 56. Cereals or other materialssuitable for pneumatic discharge may be stored in thebulk warehouse.

I3 These large vessels were transferred to the gram trade followingthe slump in the oil trade which took place from 1974 onwards.

370. At the terminal. two berths having a totallength of 297 metres are used for discharging or loadingvessels with a draft of up to 9.8 metres. There are fourpneumatic extractors on rails with four intake tubes fordischarging vessels, each with a rated capacity of 250tonnes per hour and an effective capacity of 200 tonnesper hour. Two of the extractors, each with two separatedischarge tubes, can also be used for loading but havean actual performance of only 100 tonnes per hour.

371. There are four conveyor belts, two of whichare reversible for loading ships, each with a ratedcapacity of 250 tonnes per hour. The four belts lead tothe vertical silo where the cereal is lifted to the top ofthe weighing and distribution tower. There are fourweighing bins, each with a capacity of 3 tonnes, whichallows the recording of cereal movement before stor-age. The vertical silo is made of 57 cells of 420 cubicmetres each and 40 cells of 110 cubic metres each, per-mitting the storage of about 20,000 tonnes of cereals.The silo can discharge to trucks or rail wagons. Themanning requirements vary from 14 to 41 depending onthe number of pneumatic extractors in use.

3. COAL

372. The sea-borne coal trade has grown substan-tially since the 196Os, and in 1980 reached a volume of188 million tonnes, about 9 per cent of all dry cargoshipments in tonnes. The major importing areas inorder of importance are Japan, the United Kingdomand continental Europe, Eastern Europe and theMediterranean, while the major exporting areas areNorth America, Australia, South Africa and EasternEurope. In 1980 Japan accounted for 50 per cent ofshipping demand. The majority of the coal transportedis coking coal for use in steel-making, and the remain-ing 45 per cent is thermal coal.

373. With the exception of the near-sea trades,there has been a continual increase in the average sizeof ship employed to transport coal. In near-sea trade, awide variety of sizes and types of ship, including barges,are employed; however, bulk carriers are supersedingother smaller ship types. In 1979, 74 per cent of thetotal coal trade in tonnes was transported by bulk car-riers or combined carriers of over 40,000 dwt. The bulkof this long-haul trade is handled by full shipments onconventional bulk carriers and combined carriers, withcarriers of over 100,000 dwt on some routes. Coalmakes up 22 per cent of the total dry bulk shipments by

193

FIGURE 56Plan of typical grain terminal al Marseilles

bulk vessels of over 40,000 dwt and only 11 per cent ofthe shipments of combined carriers.

374. Coal has a stowage factor which varies be-tween 1.0 and 1.4 cubic metres per tonne. All types ofcoal, even anthracite, are subject to spontaneous com-bustion caused by heating of the coal as it absorbs oxy-gen from the air. This characteristic must be borne inmind when planning the working of the coal stockpile,so as to prevent portions of the stock from lying dor-mant for long periods of time. Generally high-ash, low-volatile coals, as used for power stations, can be safelystacked, although some loss from oxidation will be in-evitable. On the other hand, high-volatile, stronglycaking coals used for coke production in the iron andsteel industry will require constant monitoring for theindicative temperature rise in the store, whilst somecoals such as steaming coals cannot be stored at all.Generally the dust nuisance is minimal and the use ofwater sprays at transfer points and discharge positionsin extreme cases will reduce this type of pollution. Adescription of a typical coal import terminal follows.

375. Coal is unloaded by means of two trolley-typegrabbing unloaders, the rail-mounted legs of whichstraddle one or more lines of ground conveyors. Alsomounted on the rail tracks is a travelling hopper which

receives coal discharged by the unloader grab. Bymeans of a feeder unit fitted to the base of the hopper,coal is discharged on to the jetty ground conveyor. Thetravelling hopper can be coupled to the unloader sothat they travel along the jetty in tandem, or it can beuncoupled and stored out of the way during occasionalgeneral cargo operations.

376. The jetty conveyor transfers material via afurther system of belt conveyors to the stacking area,where it is received by stacking belt conveyors runningthe whole length of the storage area. Mounted on railtracks on each side of the stacking conveyor is a travel-ling boom stacker. This is a specialized machine con-sisting of a tripper which discharges on to a boom con-veyor capable of being slewed through 270” and der-ricked from below horizontal to a maximum incline of15”. The stacker travels under its own power, under thecontrol of an operator, and places the coal in wind-rows.

377. Reclaiming is carried out by a bucket-wheelreclaimer consisting of a revolving wheel carrying buck-ets with digging teeth. This wheel is attached to aboom, which also carries a belt conveyor on to whichthe buckets discharge. This conveyor in turn dischargeson to a reclaim belt conveyor which runs parallel to the

194

stacking conveyor. The reclaimer. which is capable ofbeing derricked and skewed. is designed to reach to theextremities of the coal piles. and ts always under thecontrol of an operator. To recover any material nor-mally out of the reclaimer’s reach, a bulldozer is used topush the coal within the range of the reclaimer.

378. From the reclaim conveyor. coal is transferredby a further system of conveyors to a tripper locatedover loading bunkers. These elevated bunkers havesurge capacities to act as hurters between the dischargerate to onward transport and the reclaim rate at thecoal stack. The tripper rs usually under the control of anoperator whose duty is to maintain the level of materialin the bunkers, although this operation may he per-formed automatically by the introductron ot sophisti-cated equipment.

379. Below the loading bunkers are situated weighhoppers which receive a pre-determined quantity ofcoal from the bunkers. after which all further flow fromthe bunker is automatically cut off. Empty rail wagonsare located beneath the discharge outlets from theweigh hoppers. They are positioned accurately by anautomatic wagon positioner under the control of anoperator. The same operator controls the opening ofthe weigh hopper doors. permitting rapid discharge ofthe material into the wagons.

380. The enttre unloading system from the ship tothe storage area could be under the control of the shipunloader operator himself in the case of a small term-inal. whereas for a larger terminal it would be necessaryto install a central control room communicatmg with allsections and with the operators in the unloading sec-tion. Similarly. the loading into onward transport andthe assoctated stack reclaim could be controlled by theoperator of the tripper conveyor maintaining the ma-terial levels in the loading hoppers. With a larger instal-lation and an extension of automatic controls, thewagon-loading operator could be in control. An import-ant feature of such an installation is an automatic inter-lock system which prevents any section from being op-erated before the next section has been run up to theright speed. The total manning requirements of such aterminal per shift would be in the region of 28, made upof four supervisors, 14 operators and 10 shift mainten-ance staff and conveyor attendants. This figure ex-cludes the main workshop repair staff.

4. PHOSPHATES

381. Phosphate rock (minerals contarning the ferti-lizer nutrient phosphorus) is the main raw material forthe fertilizer industry and the most important commod-ity for sea-borne trade within the fertilizer group. Thisclass of minerals accounts for 2.5 per cent of total drycargo shipments, The 48 million tonnes shipped in 1980were exported from Morocco. the United States ofAmerica, other African countries and the Pacific Is-lands. An interesting development is the productron ofthe phosphate intermediate. phosphoric acid. This stepsignificantly increases the P,05 content, a measure ofthe value of the commodrty to the fertilizer industry.The terminal facilities are completely different, as theacid is a liqurd which is carrred in specialired tankers.

19s

382. The size distribution of vessels employed inthe phosphate rock trade shows that 38 per cent of thesea-borne trade was covered by vessels of less than18.000 dwt, 15 per cent hy vessels of 18.OOO to ?5.000dwt. 31 per cent by vessels of 75.000 to 40.000 dwt and16 per cent by vessels of over 40,000 dwt. The majorityof phosphate rock loading ports cannot accommodatevessels of more than SO.000 dwt.

383. Phosphate rock IS very dus ty and absorbsmoisture very readily. which can create problems forunloadmg. It has an average stowage factor of 0.92 to0.9 cubic metres per tonne. Practically all shrpments arein bulk as a powdery concentrate. A large proportion ofthe crushed rock is very fine and a great deal of dust isgiven off whenever a transfer of material takes place. It1s therefore necessary to ensure that. for example,when material is discharged from a wagon or road ve-hicle into a ground hopper, provision is made for thedispersal of the heavily dust-laden air. The materialitself is non-toxic, but it can be a nuisance to the oper-ator in constant close contact wrth it at a dischargepoint.

384. For a typical phosphate rock export terminal.the phosphate can enter the port area by two routes.The first is via a railway direct from the mmes in spe-cially designed, totally enclosed hopper wagons withroof feed openings and bottom dtscharge. The wagonsare positioned over a series of under-rail discharge hop-pers. and the phosphate is discharged by the manualoperation of the discharge doors from operating plat-forms running each side of the wagons. The wholeoperation takes place under cover with appropriateprovision for dust extractron. The second route is byroad vehicle. Since special tipper trucks are not avail-able, the trucks are discharged with the aid of tippingplatforms, again into hoppers.

385. Phosphate is extracted from the hoppers viacontrollable sliding valve doors on to a belt conveyor, asection of which automatically records the weight of thephosphate passing over it. The phosphate then travelsvia conveyors to one of two closed stores. depending onquality. where it is distributed by means of an overheadtripper. The storage shed has an “A”-frame design withthe slope of the roof equal to the angle of repose of thematerial.

386. Phosphate for shipping is extracted throughthe floor of the store by means of underground beltconveyors. the flow through each discharge point beingcontrollable by means of rack-and-pinion-operatedclam-shell doors. The angle of repose of the material issuch that a sizeable residual quantity is left to form acontingency stock. To recover this material it is neces-sary to use small bulldozers or remote-controlled dragscrapers.

387. The store’s underground extraction conveyorsdischarge on to a main conveyor and. via an approacharm belt conveyor and a transfer tower. on to two Jettyconveyors situated in a high-level structure runnmg thewhole length of the jetty. Each of these conveyors isfitted with a tripper which feeds a ship-loader.

388. The ship-loaders can traverse the full length ofthe quay and have a fixed boom with a telescopic exten-sion. Attached at the end of each telescopic section is

an extending chute capable of loading ships at all statesof the tide. The end of the extending chute is providedwith a flexible dust hood for the control of dust emis-sion, together with a deflector plate to help distributethe cargo in the hold of the ship. It is thus possible bymeans of the long travel motion along the jetty,together with the telescoping of the conveyor boom,which has in addition a luffing operation, to reach anypart of the ship being loaded. At the same time, theboom can be retracted to permit clearance of decksuperstructure and fittings when the ship-loader ismoved from one hatch to another.

389. The whole operation is under the control ofthe operator of each ship-loader, the preceding con-veyor systems being interlocked with its operation. Ow-ing to the relative closeness of the store to the ship-loader, the conveyor system will be allowed to clearitself before the ship-loader is moved between hatches,so no surge storage is required.

390. A typical manning per shift for an installationof this size would be 37, made up of three supervisors,20 operators and weighmen, six shift maintenance en-gineers and eight plant labourers and conveyor atten-dants. Because of the dust generated, several of thejobs can be arduous and dirty, thus requiring a substan-tial level of relief manning as well as adequate showerfacilities.

5 . BAUXITEIALIJMINA

391. Bauxite ore when processed into alumina isthe basic raw material for the production of primaryaluminium. Some 5.2 tonnes of bauxite produce 2 ton-nes of alumina, which produce 1 tonne of aluminium.Shipments of bauxite ore and the intermediate product,alumina, represented about 3 per cent of total dry cargoshipments, or 48.3 million tonnes, in 1980. The two rawmaterials differ greatly in bulk, in density (bauxitetypically stows at 0.878 cubic metres per tonne andalumina at 0.585) and in handling characteristics. Thetrend is towards the conversion of bauxite to alumina atsource, which more than halves transportation require-ments and therefore limits the growth of bulk shippingand terminal requirements, The share of bulk vessels ofover 25,000 dwt in total sea-borne trade was 65 per centin 1979, the size of vessel employed depending on theroute.

392. The major exporters of bauxite/alumina areAustralia, West Africa, Jamaica and Central and SouthAmerica. In the short-sea trade between the Carib-bean/South America and United States ports in theGulf of Mexico, increased use has been made ofmedium-sized bulk carriers to reduce transport costs,but a proportion of the shipments are still handled bysmall ore carriers and multiple-deck ships owned orchartered by the aluminium companies. The Australianbauxite shipments to Europe are more suitable forlarge bulk carriers, with the long haul and growingvolume of trade pointing to an optimum size of around100,000 dwt. This trade is mainly serviced by carriers of40,000 to 70,000 dwt, which have also been employedfor alumina. For the trade between Australia and

Japan/North America, medium-sized carriers of up to40,000 dwt are the preferred size.

393. The integrated structure of the world’s alum-inium industry results in many terminals being ownedand operated by the industry. These commodities, par-ticularly alumina, are dusty and require precautionsagainst plant and area pollution. A conveyor systemfeeding a closed system ship-loader, with the loadingchute in close proximity to the loaded material, willminimize material loss due to dust. Generally, pneuma-tic or closed screw conveyor systems are used to dis-charge the vessel.

Q. Multi-purpose bulk cargo terminals

394. If within a reasonable period a separate berthwill be justified to cater for a single trade, the instal-lation can be planned on that basis, permitting the mosteconomical use of plant and avoiding problems of con-tamination between materials.

395. If more than one bulk cargo trade is forecastbut throughput for each trade is insufficient to justifyseparate berths, it may be feasible to establish a bulkcargo handling terminal for more than one material.Commodities such as coal and sugar, petroleum, cokeand alumina, as well as ore and coal, can be handledwith dual-purpose facilities. In some cases the sameequipment may be used for different materials, butseparate storage will be necessary for each commodity,and particular care must be taken to ensure that thecommodities handled are compatible and that all sys-tems can be thoroughly cleaned after use. Care must betaken in handling and storage to ensure that wind-blown dust does not contaminate other products. Inother cases, only, the berthing point can be shared andseparate equipment must be used for each material.Figure 57 illustrates a multi-purpose terminal designedfor importing oil and exporting iron ore and other drybulk materials.

396. Equipment will have to be sized to give thebest compromise between the requirements of the var-ious materials handled, considering such factors as bulkcargo density, size and type of ships and size of indi-vidual cargoes. Imports and exports can be handled atthe same berth provided that there is sufficient capacity

FIGURE 57

Example of multi-purpose oil-bulk-ore pier

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to permit this and that there is no conflict in scheduledship arrivals and departures. Sufficient length must beavailable on the berth to store idle equipment in a pos-ition which permits the full length of ships’ hatches to beworked by the other equipment. It is simpler to installseparate conveyor systems for imports and exports, andthe size chosen is usually more economical than is thecase when one set of reversible conveyors is used.

397. Combining bulk cargoes and general cargo ona berth is not desirable unless annual bulk tonnages areclearly too low to warrant a separate berth. In that case

it is advisable to check on two features:

(a) Loaders and unloaders should be mobile or, ifthey are rail mounted, the layout of the berth should besuch as to provide sufficient quay length for parkingthem clear of the general cargo operational area;

(h) Conveyor systems should be either elevated ongantries at the rear of the berth or placed in tunnels sothat the working area for general cargo is not ob-structed. However, the use of tunnels should be con-sidered as a last resort because of the difficulties ofmaintenance and cleaning.

ANNEX

Bulk stockpile planning

1. The following tlssumptmns on the statistical dtstributions of thevariables affectmg the xx of the stockpile in conjunction with asimple model have been used to estmxte the stockpile requrementsas a functton of shipload and annual throughput. The interval be-tween ship arrivals follows an Erlang 2 distribution. The shipload sxefollows a uniform dlstributlon wtth a range of t10 per cet~t. Thearrival or dellvery distribution of the commodity to or from the ter-mmal also follows a normal distribution with a percentage coefficient

of variation of 10 The loading or unloadmg rate has been set to gave aberth utihzatmn of 0.4 and the loadlnglunloading follows a normaldistribution wth a percentage coeffictent 01 vanat~~n of 5

2. The model records the flow of bulk commodity in and out ofthe termmal over a period of time and calculates the maximum andthe average amounts of the commodity present. Through repeateduse of the model, an estmute of the maxm~um stockpile requirementsand the average amount of commodity stored can be determmed.

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Chapter VIII

LIQUID BULK CARGO TERMINALS

A. Introduction

398. It is difficult to provide guidelines for the de-sign of a liquid bulk cargo terminal, since the equip-ment required and the number of berths needed are notdirectly related to the total quantity of bulk liquid to behandled. This results because of the need to segregatethe invariably large number of grades of the same liquidcommodity. Thus the numbers of storage tanks andother equipment needed depend on the number of dif-ferent grades of the same commodity expected to arriveat the terminal, rather than on the total quantity. Gen-erally, the rate of discharging liquid cargo is governedby the capacity of the ship’s pumps rather than by thatof the port handling equipment. The planning of instal-lations for liquid bulk cargoes is therefore a special taskwhich is normally carried out by the industry concernedin close co-operation with the port administration.

399. The main concern for most liquid bulk termin-als is safety. Many of the commodities are inflammableor in other ways dangerous, or are a pollution risk bothat the time of loading and discharge and in storage.Both the zoning and the detailed technical layout willbe governed by these problems. All proposals must bestrictly checked from the point of view of safety andpollution, and general comments on this subject aregiven in part one, chapter VIII.

400. The general design and location of each ter-minal are of considerably greater interest to port man-agements than the technical details. The technical de-sign will depend on the actual characteristics of theindividual ships which will use the terminal. The follow-ing points should be closely checked to ensure compati-bility between the vessel and the terminal:

(a) Number, length and diameter of loading arms orhoses;

(b) Maximum height of ship’s manifold;

(c) Manifold connection specifications;

(d) Number, diameter and maximum pressure ofpier pipelines.

B. Crude oil and oil products

401. World sea-borne trade in crude oil in 1980 was1,362 million tonnes, as compared with the 1979 figureof 1,538 million tonnes. Tankers and combined carriersof over 60,000 dwt accounted for 90 per cent of crudeoil movements in tonnes, while tankers of over 200.000dwt accounted for 45 per cent of movements. Oil prod-uct movements, excluding short-sea and coastal trade,amounted to 237 million tonnes in 1980, of which a

large proportion was transported in vessels of less than60,000 dwt.

402. Large crude oil loading and discharging portsare located in quite separate and isolated points, nor-mally far from densely inhabited regions. Easy accessfrom the sea to suitable areas with calm and very deepwater is the most important requirement. The draughtrequirements often lead to off-shore terminals withstrong fendering systems to absorb the berthing impactof large tankers. For the import of oil products or smallamounts of crude oil for local refineries, the zoning ofan oil sector inside the commercial port is necessary.Methods for preventing oil spills from spreading is alsoan important consideration for the planner. The berth-ing arrangements for a typical oil terminal are shown infigure 58.

403. Crude oil and oil products have very differentproperties and may be divided into two main groups:

(a) Black oils. which include crude oil, furnace oilsand heavy diesel oils;

(b) White oils, which include motor spirits. aviationspirits, kerosene and gas oil.

The carriage of crude oils has given rise to the greatestpressure for transport economy, leading to the super-tanker concept. Figure 59 gives the length, beam anddraught requirements of such very large crude carriers(VLCC).

404. Separate sets of handling equipment are re-quired for each group of oils. Under certain circum-stances, separate sets of equipment may be necessaryfor each product, or subgroup of products within agroup, to avoid contamination. A strict pumping se-quence must be followed in the case of a common set ofequipment for a group of products.

405. Crude oils and oil products are hazardous tohandle and hence entirely separate berths, jetties orsingle buoy moorings, completely isolated from otherberths and port facilities, are invariably provided forhandling such oils exclusively. All items of equipmentare specially designed for handling these oils and aresuitable for operation in a hazardous atmosphere. Toprevent the build-up of static electricity, electricalearthing cables need to be built into the quay or pier.

406. It is recommended that loading and unloadingarms should be of fabricated mild steel and operatedeither manually or hydraulically. Suitable hoses may beused in some cases where quantities to be handled aresmall. for example with tankers of 18,000-tonne capac-ity, and where operating pressures and tidal variationsare low. Depending on the design discharge or loadingrate, the arms may be from 200 mm to 500 mm in

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FIGIIRF 58

Typical jetty arrangement for tanker terminal

FKJLIRE 5Y

Principal dimensionr of very large crude carriers

diameter. The rate of pumping from shore to ship willvary widely according to the size of the ship to beloaded. the limitations of its equipment for receipt ofoils. and the turn-round time planned. As ships’ capaci-ties vary from 500 tonnes to 500.000 tonnes, the rangeof variation is great. The rate of pumping from ship toshore is governed by the capacity of the ship’s pumps.Normally. four cargo pumps are installed. with a typicalcombined dtscharging rate of 6.500 cubic metres perhour for a hO.OOO-dwt tanker and 15.000 cubic metresper hour for a 200.000-dwt tanker.

407. Mild steel pipelines are invariably used. with adiameter normally between 150 mm and 900 mm. Evenlarger diameters are possible, dependmg on the quanti-ties to be handled. Pipelines for furnace oils and otherheavy black oils may require trace-heating or lagging(covering with insulating material) in temperate cli-mates. Centrifugal pumps are normally used, except forheavy black oils for which positive dtsplacement pumpsor rotary pumps may be necessary. Some heavy blackoils require heating. even in sub-tropical climates.

408. If products are being pumped through pipe-lines for a distance of oyer 3 kilometres. pipeline pig-ging equipment may be necessary to flush the lines inorder to avoid excesstve contamination when changing

products. or to clean the lines to increase flow. Piglaunching and recovery equipment allows the insertionof a hard rubber sphere. or pig. into the pipeline. Thepig is forced along the pipe by the oil pressure to the pigtrap, where it is recovered. Because of the hazardousnature of these oils, good effective communication be-tween various points along the pipeline is of vital im-portance. A special telephone system or radio com-munication system designed for use in such a hazardousatmosphere is required.

409. Spillage collection and disposal equipment isrequired for pollution control areas where spillage islikely to occur-for example, at points where hoses areconnected and disconnected and where pigs are laun-ched or recovered. The equipment consists mainly of

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an underground or low-levei mild steel tank of ade-quate size and a small pump for the disposal of thecollecting tank’s contents back to the appropriate pipe-line or tank. In addition, facilities to contain and cleanup accidental spillage into the sea, such as oil boomsand specialized skimming craft, should be provided.

410. In the case of exporting countries, it is re-quired that ballast water from ships should be dis-charged ashore before loading. The oil contaminatingthe water must be separated out before disposal of thewater. Suitable equipment, including tanks, oil-waterseparators and pumping equipment are therefore re-quired.

411. An elaborate system of fire-fighting equip-ment is required at all hazardous points. The first re-quirement for this purpose is an adequate supply ofextinguishing liquid: water for a non-petroleum fire,and foam for an oil fire. The main items of equipmentrequired are high-pressure pumps, pipelines, hydrants,foam storage tanks and distribution pipelines, monitor-ing towers and suitable mobile equipment. Provisionwill need to be made for the storage of an adequatequantity of water if the supply of water is not reliable.Sea water can be used for fire-fighting purposes withsuitable equipment designed for the handling of saltwater.

412. Welded mild steel tanks are required for thestorage of petroleum products. Two distinct groups ofstorage tanks should be erected, one group for blackoils and one group for white oils, each group beingsurrounded by bonded wails of adequate height. Twotypes of tanks are available, one type with a floatingroof and the other with a fixed cone-roof. The formertype reduces evaporation losses while the oils are instorage. All tanks normally have sumps for draining.The capacities of tanks are usually between 500 and20,000 cubic metres, but can be even larger, dependingon requirements. The weight of tanks, and thus alsotheir height, is restricted by the soil conditions in thearea. The heating and lagging of tanks may be neces-sary for heavy black oils in temperate climates. The

measurement of quantities in tanks is carried out bydipping or by means of specially installed gauges. Spe-cial laboratory equipment, also, is necessary for thequality control of products.

C. Liquefied natural gas

413. Cryogenics is the branch of physics that relatesto the production and effects of very low temperatures.Liquefied natural gas, commonly known as LNG, istransported at approximately atmospheric pressurewith a temperature of -161°C. The expansion coef-ficient for LNG to a gaseous form is 630 times theoriginal volume. Liquefied petroleum gas (LPG) is pro-duced in conjunction with petroleum refining and oil-field production. LPG must be transported underpressure, as contrasted to LNG, which can be trans-ported at atmospheric pressure but under extremelylow temperatures.

414. The hazardous nature and the very low tem-peratures of LNG necessitate special facilities entirelyisolated from the rest of the port. Surfaces in contactwith LNG must be manufactured from alloys to with-stand very low temperatures, as ordinary steel wouldbecome as brittle as glass.

415. A wide variety of complex equipment is re-quired for liquefaction, storage, refrigeration, loading,unloading and regasification of LNG. Depending uponthe distance from the gas production area and otherfactors, not all of these processes may be carried out atthe terminal. However, insulated pipelines and insu-lated storage tanks with refrigeration plant are requiredfor storing LNG in the terminal. Typical export storagetanks have a capacity of 300,000 barrels, or 47,750cubic metres.

D. Vegetable oils

416. This heading covers a variety of oils-for ex-ample, palm kernel oil, cotton-seed oil and coconut

FIGURE 60

Typical vegetable oil installation

PlPELlNES

oil--each having different properties and specific gravi-ties, Some of them are in a solid state at ambient tem-peratures and require heating. The handling equipmentrequired will. therefore, vary, hut a typical installationis as shown in figure 60.

417. Handling temperatures range from 15’C to65°C. When heatmg is necessary, the maximum tem-perature change over 24 hours should not exceed YC.Oils should not be repeatedly heated and cooled as thisresults in a deterioration of their quality. The specificgravity varies between 0.X and 0.95, dependmg on thetype of oil and also on its temperature.

418. For loading on to the vessel, special rubberhoses smtable for handling vegetable oils are preferred.However. mild steel loading or unloading arms withspecial internal linings may be used. Hoses or loadingarm sizes normally vary from 150 mm to 200 mm indiameter. Smaller hoses are required for the unloadingof rail or road tankers. Suitably designed cast ironpumps should be used. Centritugal pumps are normallyused for this application, but rotary-type or mono-typepumps are also suitable. The normal pumping rate forshore-to-ship pumping is 100-150 tonnes per hour.

419. For plpelines. unhned stainless steel pipes of150 mm to 200 mm are recommended. The heating andinsulation of pipelines may also be necessary in temper-ate climates. The main valves in tanks and pumpsshould be of cast steel. All other valves may be castiron. The washing down of pipelines is carried out withthe use of suitable detergents. Pipelines are flushed bymeans of spherical pigs. Pigging equipment for piglaunching and pig recovery is therefore installed at suit-able locations.

420. Vegetable oils are stored in welded mild steeltanks with a suitable internal lining. As quantities ofbulk vegetable oils handled are relatively small, a tankcapacity is normally about 1,000 tonnes or less. Allstorage tanks should be filled from the top. For certainfatty oils. draw-off points should be provided at variouslevels along the side of the tank. Storage tanks may besited outside the port area if necessary, due regardbeing given to the limitations of the pumping equip-ment. Quantities in tanks are normally measured bydipping. Tank cleaning and washing equipment is alsorequired. particularly when a different type of veg-etable oil is to be stored in the tank.

421. Covered loading gantries with retractablepipes with swivel joints. or suitable rubber hoses,should be provided for loading road or rail tankers.Special meters are also provided on the gantries tomeasure the quantity received or delivered. Purpose-built road or rail tankers, possibly with heating equip-ment. are required. Off-loading pumps may need to beprovided if the vehicles are not so equipped.

E. Molasses

422. Molasses is a viscous, dark-brown syrupdrained from sugar during refining. Temperature con-trol is important both in handling and storage since

below 32°C the product solidifies and above 38°C itcaramelizes (i.e. becomes sticky like toffee). The speci-fic gravity is 1.34. The handling of molasses differs fromthat of vegetable oils.

423. Hoses for loading or unloading of ships shouldbe 250 mm diameter or greater and are normally hand-led by ships’ derricks. Mobile cranes may also be re-quired for handling hoses out of reach of ships‘ der-ricks. Hoses for the loading or unloading of road or railtankers should not be of lesser diameter than 150 mm.Only positive displacement-type pumps or rotarypumps, with positive suction head and double bypass toassist start-up, should be used. Normal ship-to-shorepumping rate is 150 tonnes per hour.

424. Pipehnes can be of mild steel or cast iron, butpipe diameters should be 5OG600 mm. Cast steel gatevalves should be used throughout. Pipelines and hosesshould be cleared by compressed air and washed downwith fresh water after use.

425. The high specific gravity of the liquid requiresspecially designed welded mild steel tanks with fixedroofs. No internal tank lining is necessary. A typicalcapacity of storage tanks is 14,000 tonnes. Hydrostaticgauges should be provided for the measurement of thetank contents.

426. Road or rail tankers should be purpose-built.and should be lagged and provided with heating facili-ties and off-loading pumps with 150 mm-diameter out-lets. The average capacity of such tankers is 30 tonnes.It may also be necessary to provide weigh bridges tomeasure quantities loaded into road or rail tankers.

F. Rubber latex

427. Liquid latex is a milky viscous sap exudedfrom rubber trees when tapped. Approximately 36-38tonnes of rubber are obtained from 100 tonnes of latex.The fluid is miscible with water, and forms rubber bycoagulation. The coagulation of latex can be preventedby the addition of ammonia or foremaldehyde. Tem-perature control is important and the temperatureshould not be allowed to fall below 5°C or rise above32YC. The normal tank storage temperature is about29°C. The specific gravity of liquid latex is 0.94.

428. Special rubber hoses. normally of 150 mm or200 mm diameter, are used. Screw displacement-typepumps or mono-pumps with a neoprene stator are re-commended for this purpose. Centrifugal pumps mayalso be used. The normal pumping rate for loadingships is 150-200 tonnes per hour.

429. Pipeline and storage tank requirements forrubber latex are similar to those for vegetable oils, butin the case of rubber latex it is generally recommendedthat stainless steel ball valves should be used. Dia-phragm valves may also be used. The capacities of stor-age tanks vary between 200 tonnes and 2,500 tonnes,and an internal coating of microparaffin wax is some-times applied to the walls of the tank to prevent theformation of deposits of rubber.

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G. Liquefied ammonia

430. Ammonia is a colourless anhydrous gas, with abitter smell. While ammonia is not easily inflammable,when mixed with air or with oxygen it can form anexplosive mixture. It is a highly irritant and toxic gas,dangerous to the eyes, skin and respiratory system.Anhydrous ammonia contains nitrogen, which is one ofthe basic elements in fertilizers. Liquid ammonia isused primarily to produce nitrate fertihzers (ammonianitrate) or compound fertilizers (granulated compoundfertilizers).

431. Ammonia gas becomes liquid when cooled to-33°C at atmospheric pressure. Liquid ammonia istransported by special carriers of 3,000 to 40,000 dwt.Delivery to land-based tanks is by means of the ship’spumps with typical discharge rates of 600 tons per hour,with 6-inch articulated arms and ammonia at -33°C.One or several such arms connect the ship’s intake withthe thermally insulated land-based pipes.

432. Storage tanks must be protected from solarrays, heat and all products which react when mixedwith ammonia. Temperature must be maintained at-33°C by means of compressor sets. The design shouldminimize the chance of direct discharge in the event ofan accident. The storage depot must be provided withgas masks in a central well-identified location with easyaccess. A water-sprinkling system with a high dischargerate must also be provided.

H. Phosphoric acid

433. Phosphoric acids made from natural phos-phates are green- or brown-coloured sticky liquids. At20°C the specific gravity of a 50-per-cent solution oftechnical phosphoric acid is 1.65. Technical acids arecorrosive for metals such as iron, zinc and aluminium.Stainless steel, copper, bronze, brass, some plastics,rubber and acid-proof paints are resistant to phosphoricacid at normal temperatures. At temperatures above8o”C, only glass, ebonite, carbon and acid-proof refrac-tory materials resist completely. While phosphoricacids are non-inflammable and non-explosive com-pounds, they react with many metals by releasing hyd-rogen which can result in explosions and fires. Phos-phoric acids cause irritation to the skin and eyes.

434. Phosphoric acids are used in the manufactureof fertilizers, as they contain phosphorus. They aremixed with other fertilizing compounds, either as acidsor after neutralization by ammonia. Transportationtakes place in special vessels up to 25,000 dwt and thedischarge and loading operation is done through stain-less steel pipes and a ship-to-shore hose connection.Typical rates are 600 tons per hour.

435. Phosphoric acids are stored in steel cisternswith an inner lining of rubber (self-vulcanizing 4-mm-thick rubber sheets). The cisterns stand in watertightconcrete tanks that can hold the contents of a full cist-ern in case of leakage or accident.

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Chapter IX

MISCELLANEOUS FACILITIES

A. Service craft

436. Port planning requires the provision of ad-equate accommodation for service craft. These craftinclude tugs, barges, fire-boats. water taxis, trashboats, pilot boats and floating construction and main-tenance equipment such as pile drivers, salvage anddredging equipment, cranes and floating oil-spill equip-ment.

437. The principal service craft are likely to be thefleet of tugboats, barges and pilot boats. Tugboats areused for towing, docking, undocking and shifting ves-sels. Tugs also provide the needed towing capacity formoving barges and other types of floating equipment.Barges can be used for delivering bunkers and drinkingwater to vessels at berth or anchorage. Pilot boats arerequired for placing pilots on vessels as they enter portand taking pilots off as vessels leave. The ptlotage areashould therefore be placed in a position near the en-trance to the port.

438. Service craft, with their limited draught re-quirements. present little problem to the port plannerin terms of providing adequate water depths. However,sufficient calm water berthing space and suitable dock-ing facilities must be made available for these essentialactivities.

439. Berthing facilities that were built for otherpurposes can often be economically converted for useby service craft. In ports where berths have becomeobsolete due to increasing ship size. the old berths canbe converted for service craft. In new ports, the mari-time facilities provided for the floating units used onthe construction may be designed so that later they canact as a harbour for the service craft.

B. Service facilities

440. Ship operators use their stay in port for work-ing cargo also to service their ship. These services canbe broadly divided into four groups: fresh water; bunk-ering and lubricating oils; ship repairs: and provisions.

441. The supply of fresh water is a basic necessity,and the quantity required will depend upon the dura-tion of the voyage, the ship’s capacity to produce freshwater while at sea and its capacity in terms of availabletanks, taking into account the loading of cargo and fuel.Demand for fresh water will be high if shore suppliesare cheaper than the cost of making fresh water byships’ plants during the voyage.

442. Berth design should therefore provide forfresh water pipelines with metered outlets for connec-tion by flexible hoses to the ship’s tanks. The pipeline

system can be connected to an overhead tank system sothat pressure available would be sufficient to supplywater to a ship at the rate of 15-20 tons per hour in a2.5-inch pipeline.

443. Another facility for water supply, both forships at buoys and at berth when demand is heavy (forexample for passenger vessels). is water barges. Thebarges can load fresh water trom shore sources andmove to the ship’s side under tow or under their ownpower if self propelled. They are fitted with pumpscapable of delivering water through flexible hoses at arate of 50-100 tons per hour.

444. Also for limited quantities. water can be sup-plied by S-S-ton road lorry tankers which bring water tothe ship’s side.

445. Bunker facilities for ships are a basic servicefacility which can also provide a profitable source ofrevenue for ports. Bunkers can be provided by pipe-lines connected to oil storage installations; the rate ofsupply usually varies between 50 and 100 tons per hour.Alternatively, tank lorries may be used.

446. Ships at buoys can be supplied by a flexiblefloating pipeline connected to the shore prpeline outlet.Bunkering at buoys can also be carried out with oilbarges. Lubricating oil needs are normally met by sup-plying oil in drums.

447. Facilities for ship repairs vary according to theextent of the work. Major repairs will require dry dockfacilities and major marine workshops. These are fullyfledged industrial facilities, which are discussed furtherin section F below.

448. Minor above-water repairs. repairs to wirelessand radar, and to equipment and engines are availablein most ports through marine engineering firms. Theserepairs can be undertaken and finished at berth duringthe normal stay of a ship.

449. However, if there is adequate demand, it maybe possible to allocate one or two berths especially forship repair, where these berths are ill suited for cargoworking. Ship repair berths may require less draught asbulk vessels and tankers will most probably be repairedwhen empty. At the rear of the quay, repair and ca-reening shops will be served by ship-repairing cranesthat usually have a counterbalanced long-span jib,slewing on top of a high tower and running on railsparallel to the quay.

450. In repair centres where oil tankers will be re-paired, a degassingideballasting station must be pro-vided. This receives ballasting and de-aerating watersfrom tanks containing petroleum products, and it facili-tates the separation of petroleum products from waterin settling basins. Water so purified must comply with

the international standards for its petroleum productcontent before being discharged into the sea.

451. Provisions for crews will require recognizedship-chandlers at the port who can procure and supplygrocery items and other stores to ships calling at theport. These trading firms normally require no port fa-cilities.

452. However, certain provisions such as spirits,cigarettes and some groceries may not be locally pro-duced, but must be supplied from imports. When theyare re-exported to ships, they will not be liable fornational customs duties. Such stores are thereforestored in customs bonded warehouses which may be inthe port area to allow rapid supply. The goods are re-leased with the appropriate documentation and trans-ferred to the ship under customs escort.

C. Passenger terminals

453. The planning of passenger terminals is outsidethe scope of this handbook and is therefore only brieflymentioned. A fuller discussion of the subject may befound in Nagorski’s book on port problems in develop-ing countries.” The trend for some years in passengervessels has been towards cruise-type ships which areactually tending to become smaller rather than larger.The average size of cruise ship is at present about20,000 gross tonnes but it will probably fall to thelO,OOO- or 12,000-ton mark. Cruise vessels drawing lessthan 8 metres, are equipped with special manoeuvringgear so that they manoeuvre safely in a limited spaceand usually accommodate some 1,000 passengers. Mostorders being placed are for combined passenger andcar-ferry vessels.

454. Passenger ships can use genera1 cargo berthswhen certain specialized facilities are provided. For ex-ample, a second storey on a transit shed may serve asthe passenger terminal building with facilities for CUS-toms, immigration and health. However, the allocationof passenger ships to general cargo berths can causeproblems in view of the priority which normally has tobe given to cruise vessels and other passenger liners,and the disruption of cargo operations which this cancause. The passenger ship traffic must be taken intoaccount when calculating the number of commissiondays available for the general cargo traffic using theterminal. Where passenger or cruise traffic is substan-tial, it is advisable either to allocate a separate berth orto provide a well-sheltered mooring and a fleet of laun-ches. This latter alternative is not possible when a com-bined passenger and rolro type service uses a port.

455. If a port authority decides to provide a passen-ger terminal, the following points should be consid-ered:

(a) The location of the terminal should be such thattraffic jams will cause minimum disruption to cargoflows to and from the port;

I4 B. Nagorski, Port Problems in Developing Countries- Principlesof Port Planning and Orgonizarion [Tokyo, International Associationof Ports and Harbors, 1972).

(6) Open and sheltered areas will be required for thefreight to be carried;

(c) Car parks are required for staging of vehicles if aro/ro service is offered, and for vehicles meeting pas-sengers;

(d) The terminal building will provide facilities for anumber of services and be connected to the passengervessel by telescopic gangways;

(e) A shore-based or floating ramp wall will be re-quired for roiro services.

456. The passenger traffic and the cargo and ve-hicle traffic should be separated. The terminal buildingis likely to have several floors. The ground floor willhave shops, foreign exchange, car-hire agencies, ship-ping companies, a tourist information office and wait-ing-rooms. The first floor will be assigned to servicesand controls such as customs, police, luggage, operat-ing staff, shipping company, forwarding agents, postoffice and telephones. The upper floors are reservedfor caterers with restaurants and self-service cafe-terias The terminal building will also be provided withramps or lifts for disabled people and for the transferof luggage from different levels.

457. To promote this traffic, local authoritiesshould simplify procedures to facilitate passengermovement. A sufficient number of control stationsmust also be provided to prevent long delays to passen-gers and vehicles.

D. Fishing ports

458. A fishing port is no longer a point of transferof goods from one mode of transport to another.Rather it is an industrial zone for unloading, processingand marketing fish as well as for maintaining and ser-vicing the fishing fleet. In consequence, a fishing port isan integral part of the national fishing industry ratherthan part of the country’s transportation system. Amodern fishing port is an important element in promot-ing the fishing industry of a country.

459. Facilities for handling a fishing fleet can be inthe form of a wharf or jetty in shallow water, usually atthe extremity of the normal cargo-handling areas, or ina special basin. This separation is desirable to isolatefishing smells from commercial port operations. Wherefishing is a more important activity, a quite separate,well-selected location is needed. If the number of boatsto be accommodated is considerable, a large area ofsheltered water is required, while the numerous facili-ties will necessitate the provision of substantial spaceon land.

460. Local fishing boats can be expected to have amaximum draught of 2 metres, while larger motor traw-lers and fish carriers may draw up to 3.5 metres. Berth-ing facilities for high-sea fishing with large trawlers re-quire a cl-metre draught. An unloading quay apronwidth of 6 metres is sufficient. The apron should have aslope towards the waterfront, normally of 1 in 20, tofacilitate washing down.

461. The length of unloading wharf should nor-mally be sufficient to complete the unloading of all

2 0 4

boats active in the local fleet during the peak period.The factors to consider when determining the length ofquay are as follows:

(a) Average and peak number of vessels unloadingtheir catch at one time;

(h) Quay length per vessel required during un-loading;

(c) Average and peak quantity of catch unloaded pervessel;

(d) Unloading speed, including preparation time be-fore and after the actual unloading;

(e) Time available for unloading during the day.

462. For hygienic reasons and to preserve a highdegree of quality of the fish, the unloading operationshould be carried out as quickly as possible. Quaysidecranes or derricks may be required, and in special casespneumatic systems, vertical and hortzontal conveyorbelts, bucket elevators or pumps may be used.

463. After unloading, the boats are normally berth-ed herring-bone fashion or double banked. The berth-ing space required will depend on the number of boats,peak periods determined by national holidays or fishingpatterns, and the availability of mooring or anchorageareas.

464. A covered hall. extending the length of thewharf, is needed for washing, sorting, boxing,weighing, icing, marketing. distribution and possiblystorage. The hall should consist of two sections separ-ated by a wide alley-way. The waterside section, usedmainly for washing fish, should slope to the watersideand may be 8 metres in width; the landward side, usedfor sorting and packing, should be of similar width andhave a rear loading platform for trucks. The total widthof the hall should thus be approximately 25 metres.

465. The floor of the shed should be provided withan anti-skid surface. In the shed, running water andelectric power for lighting must be available. The watersupply is often separated into a fresh and a sea watersupply, with the latter having high pressure and capac-ity for cleaning purposes. The electrical system requiresspecial specifications because of the wet and corrosiveenvironment.

466. Open areas for drying and repairing nets, forrepairing boats, and for slipways and a workshop arealso needed. The remaining facilities needed may be:

(a) A cold storage plant;

(b) An ice-making plant;

(c) Provision stores;

(d) Gear sheds;

(e) Fuel tanks;

(J) Electric lighting;

(g) A fresh water distribution system;

(h) Fire-fighting equipment;

(i) Offices, rest-rooms and a canteen;

0’) Fish-processing plants;

(k) Fish-meal factories.

467. The above brief comments on fishing port faci-

lities give an indication of the main points to be con-sidered. Further details are given in a report on thesubject by the FAO.”

E. Marinas

468. Where the development of a marina forpleasure craft falls within the port authority’s jurisdic-tion, reference can be made to various PIANC reportson the subject of pleasure navigation.” Another source

of information is the report on small craft harboursprepared by the American Society of Civil Engmeers inthe series of manuals and reports on engineering prac-tice.”

469. In general, a marina will need to provide pro-tection (sheltered water), navtgational aids. an anchor-age basin, open moorages and a marine service station.On land, administration and supervisory facilities,marine supply store. general stores and public toiletsand showers will be required to assure successful opera-tion. Other facilities to consider are launchmg rampsand derricks or crane lifts for the transfer of boats be-tween land and water.

F. Dry docks and floating docks

470. Ships must be regularly dry-docked so that thehull, propeller. rudder blade and bow thruster can bechecked, cleared of seaweed and barnacles and if needbe, repainted. In case of damage, dry-docking may alsobe required to carry out the repairs. The required facili-ties are costly and to be profitable must be used inten-sively.

471. Dry docks require a suitable supporting found-ation. From the outside they resemble locks; however,one end of the dock is permanently closed. They in-clude a pumping station to drain and keep the dock dry,a supporting system (props and keel-blocks) to hold theship and long-span. heavy-lift capacity cranes.

472. Dry docks are expensive works, whose econ-omic life may be as long as 100 years. Therefore provi-sion for future ship sizes should be made when deter-mining the dimensions of the dock. When there isroom, the length of the dock may be extended withoutproblem. The design length will be 5-10 metres greaterthan the length of the largest ship. the width 4-6 metresgreater than its beam and the depth 0.5-l metre greaterthan its draught. Cranes will run on rails along the sidewalls. A repairing berth may be located on the outerside of a lateral wall which will permit use of the cranesfor both facilities. Dry docks require limited main-tenance.

I5 FAO. “Rshery harbour planning”. Fisheries Technical PaperNo. 123.

” See in particular the final report of the PIANC lnternat~onalCommmmn for Sport and Pleasure Navigation (annex to BulletinNo. 25 (Vol. IIIi1976)) and the reports on standards for the const~nc-t i on , equ~pmem and operat ion o f yacht harbours and mar inas. on thelayout and structure of approach and protectwe stT”ctwCs. and onthe land storage of yachts (Supplement to Bulletin No 33 (Vol II/1979)).

” American Society of Civil Engmeers. Report on Small CraftHurbors (NW York. 1969).

205

473. Where the bearing strength of the soil is li-mited and if deep water is available, a floating dockmay be a better alternative. A floating dock is normallya steel structure, comprising a horizontal float (apron)and two side walls that keep the structure rigid andstable during operation. The dock has both ends open.

474. The dock is submerged to a depth that willallow the ship to enter it. The ship is then secured to thedock and watertight caissons are emptied by means ofpumps until the apron rises above sea level, so that theship is raised out of the water. The side walls normallycarry travelling cranes.

475. Floating docks are characterized by their lift-ing capacity, which corresponds to the ship’s displace-ment. Usually a 20,000-ton dock can accommodate anunladen vessel of 50,000-60,000 dwt. The great advan-tage of floating docks is their mobility, which allowsthem to be moved within the port or to another port.

476. However, the maintenance for a floating dockis greater than that required for a dry dock. Modernfloating docks are welded steel structures and theirplates, which are alternately exposed and immersed,are prone to pitting and to the attachment of seaweed.Cathodic protection can be used to prevent corrosionand the immersed section can be cleaned and paintedby sinking only one side of the dock, which lifts theother side out of the water.

G. New types of marine transport vessels

477. Research and development in the field of

marme transport technology has produced several newtypes of vessels, vehicles and methods of propulsion.Two of these types are the hovercraft and the hydrofoil.None of these new types of craft are expected to be of asubstantial size and it is likely that they will remainlimited to ferry services carrying passengers andvehicles.

478. Speed, manoeuvrability and lack of wash andwake are the main advantages of hovercraft. Theamphibious flexible skirt hovercraft requires a wideshallow concrete ramp with a maximum slope of 1 in20, rather than a berth. Old lighterage berths could bereadily converted to this use. All cargo-type hovercraftare still in the early stages of development.

479. At present hovercraft are limited to carryingpassengers and vehicles. Hovercraft rest on a limitednumber of supports which therefore require strongpavements to sustain the heavy loads. Facilities for thepassengers and vehicles are as for a passenger terminal.

480. The use of hydrofoils has been confined tohigh-speed passenger ferry services and military ves-sels. Hydrofoil craft at present do not require morethan 3 metres of draught and therefore passengerberths can be used with a special gangway.

481. The port authority should be ready at theappropriate time to provide facilities for these newtypes of craft. As it is difficult to estimate the futureneeds in terms of land area and water frontage, themaster plan should allow for the necessary flexibility toaccommodate these developments.

206

ANNEXES

Annex I

GENERAL INFORMATION

A. Conversion factors

I LE”IOrtl

I centmetre (cm) = 10 mllhmetrer (mm) = 0.3Y37 mches (in J1 metre (In) = 100 cm = 3 2808 ieeL (ft)1 kdometrc (km) = 1000 m = 0 6214 mdes (mi)

I inch = 2.S400 cm1 foot = 12 m = 0.3048 m1 yard (yd) = 3 ft = 0.9144 m1 fathom = 6 ft = 1.8288 m1 mile = 5,280 ft = 1.6093 km1 nautical mile = 6,080 ft = 1.8531 km

2. AREA

1 sq sqmetre (m’) = 10.000 cm (cm’) = 10 7638 sq ft1 hectare ihai = 10.000 m’ = 2.4711 acres1 sq km (in?) = 100 ha = 0.3861 sq m i

1 sq sqyd = 9 ft = 0.8361 mz1 sue = 4,840 sq yd = 4046.9 m’

3. VOLUME

1 cu m (d) = 1,000 litres (1) = 1.3080 cu yd= 35.3147 cu it

1 cu ft = 0 02832 m’1 cu yd = 27 cu ft = 0.7646 m3

4. CAPACITY

1 htre (1) = 1000 cu cm (cm3) = 0.035315 cu ft= 0.2200 Imperial gallon= 0.2642 US gallon

1 hectolitre = 1 0 0 1 = 22.00 Imperial gallons= 26.42 US gallons

1 pmt = 0.5683 litres1 US eallon = 3.7854 litres

= 0.8327 Imperial gallon1 Imperial gallon = 4.5461 litres

= 1.2009 US gallons1 lmpenal bushel = 1.2844 cu ft = 0.03637 m3

= 8 Imperial gallons = 1.0321 Amencan bushels1 American bushel = 1.2445 cu ft = 0.03524 m3

= 0.9689 Imperial bushel1 US barrel = 5.6146 cu ft = 158.99 litres

= .15899 In3= 42 US gallons= 34.9726 Imperial gallons

1 gross register ton = 100 cu ft = 2.83 m3 of permanently enclosedspace

1 net register ton = 100 cu ft = 2.83 m3 of permanently enclosedspace for cargo and passengers

1 shipping ton = 40 cu ft = 1.13 m’ of permanently enclosed cargospace

Gross tonnage:

Net tonnage:

measure of overall size of a ship derermmed maccordance with the prows~~ns of the IMO Interna-t,onal Conventmn on Tonnage Measurement ofShips (Regulation 3). whtch came mto effect in July19X2. The gross tonnage 1s equal to the volume of allenclosed spaces of the ship m cubx metres, adlustedby a factor related to the overall volume

measure of the useful capacity of a ship determmedm accordance with the IMO Convention on Ton-nage Measurement (Regulation 4).

5 WEIGHT”

1 gram (g) = 0.002205 pound (lb)1 kilogram (kg) = 1,000 = 2.2046 lbg1 tonne = 1,000 kg = 2204.6 lb

= 0.98421 long ton= 1 10231 short tons

1 pound = 0.4536 kg1 hundredweight (cwt) = 112 lb = 50.802 kg1 long ton = 2240 lb = 1 0165 tonne

= 35 cu ft of salt water = 1.12 short tonsI short ton = 2000 lb = 0.90719 tonne

0.89286 long ton

6 . UNITIZATION

(a) IS0 pauers

1A1AAIB1BB1cICC1DIE1F

t.,remd dmmmmfmosr we@

Milhle,,es Feet ImPm‘ mnr,

12 1 9 0 x 2 438 x 2 438 40~8x8 30.51 2 1 9 0 x 2 4 3 x x 2 5 9 1 40 x 8 x xv2 30.5

9 1 2 5 x 2 4 3 8 x 2 438 30X8X8 25.49 1 2 5 x 2 43R x 2 5 9 1 30 x R x 8% 25 46 058 x 2 4 3 8 x 2 438 20X8X8 20.36 058 x 2 4 3 8 x 2 591 20 x 8 x 8% 20.32 9 9 1 x 2 4 3 8 x 2 438 10X8X8 10.21 968 x 2 438 x 2 438 w x 8 x 8 7 . 11 460 x 2 438 x 2 438 5~8x8 5 . 1

207

--

7 . GRAINS (STANDARD)

Twe Poandiilmpenni brrrhds impenoi bwhsidlong ,o,i

Wheat 6 0 37.3Maize 5 6 40.0Soya beans 6 3 35.6Barley 48 46.7O a t s 3 2 70 0Rye 56 40.0Sorghum 59 38.0

1 01 21 41 61 82 022242 6283 0323 4363840424446485 0 . .5 56070

1.000 6.30 6.40,986 6.39 6.50,973 6.48 6.58,959 6.57 6.68,941 6.66 6.76,934 6.75 6.86,922 6.84 6.95,910 6.93 7.04,898 7.02 7.13,887 7.10 7.22,876 7.19 7.31,865 7.28 7.418 5 5 7.37 7.49

,845 1.46 7.58,835 7.55 7.67,825 7.64 7.76,816 7.73 7.85,806 7.82 1.95,797 7.91 8.03,788 8.00 8.13,780 8.08 8 . 2 1,759 8.30 8 44,739 8.53 8 h7,702 S . 9 8 9.12

99.898.49 7 . 195.194.593.292.090.889.688.587.486.385.384.383.382.381.480.479.578.677.875.773.770.1

B. Commodity characteristics

1. Table I IS intended to help port planners in several tasks:

(a) The conversion of traffic forecast figures given m tons intoshiploads, according to ship SIX, for the planmng of probable shipcalls;

(b) The conversion of tonnages of a cargo mix into the volume offuture port storage capacity required;

(c) The grouping of commodity forecasts into fotals to be allocatedto each class of port terminal and of port storage.

2. The list of commodities Included is not exhaustive but shouldcover the overrlding majority of traffic offered to a port. In the caseof general cargo, it is not possible to be comprehensive but sufficientdata is given to permit the conversion of a prelimmary general cargomix tonnage to a volume requirement.

3. The stowage factors given have been mamly derived from astandard work.c The stowage factor of any commodity is the figure

h Specific gravity = 141.5mgrses API + 131.5

which expresses the number of cubic feet or cubic metres which a tonof 2,240 lb will occupy in stowage and includes a proper allowance forbroken stowage and dunnage. These stowage factors are not absoluteand should serve merely as a useful guide m the absence of localfigures. In most cases only a central value in each range is given, ~mceit will not normally be feasible to deal with a range of values duringthe plannmg task. Tins approximation is sometimes very rough, bur itwill generally be at least as accurate as the traffic forecast itself. Thetable is intended for use in the estimation of storage requirementsand not for the purpose of accurate operational planning for specificship cargoes.

4. Similarly, the degree of accuracy called for is not so great as towarrant differentiating between the stowage factor of a ship, thestowage factor in a port store, and the weight/measurement ratiogiven in the consignment documents. The figures given can, withinthe limit of forecasting accuracy, be used interchangeably for each ofthese cargo characteristics for port development studies.

C. Discount factors

5 . Table II provides factors to allow discounted cash flow analy-ses to be made. For example, when the rate of interest or time valueof money is 12 per cent, the present value of a sum of money that willbe received after five years is 0.56743 rimes the sum of money.

6 . The discount factor is calculared by the formula:

d.f. = &j~

whered.f. = discount factor;

r = annual rate of interest as a fraction;n = number of years before swn received

D. Amartization factors

7. Table III provides factors to allow the calculation of capitalcharges based on the life of the asset and the rate of interest. Forexample, an item of equipment cosrmg $100.000 wth a life of 10years and a rate of interest of 10 per cent would have an annualamortzation charge of $100,000 times 0.16275, or 616,275.

8. The amortization factor is calculated by the formula:

wherea.f. = amortizatlon factor;

r = annual *ate of interest as a fraction;n = hfe of the asset.

E. Random number table

9 . Table IV, a table of random numbers, is provided to allow theuse of such techniques as the Monte Carlo simulation. To select arandom sample the user must decide upon an arbitrary method ofchoosing entries from the table. He must then decide upon somearbitrary method of selecting the required number of positional digitsfrom each entry. For example, the first and the last digit of each entrymay be used to give a two-dlgit number. The procedure is repeateduntil a sufficient number of samples is obtained.

208

TA B L E I

Selected commodity characteristics for port planning

LIQUID CARGOES

Crude oilOil productsL a t e x

V e g e t a b l e o i l s

! .2 (42)1.2(43)LO(37)

1.1(39)

PIpeline TankPIpeline TankPlpeline Tank

Drums1.5 (52)

Pipeline TankBarrels, drums

1X(64)M o l a s s e s 0.R (27) PIpeline Tank

Baskets, casks1.4(50)

WtnesCasks, tanks

1.8 (63)

DRY CARGOES

Ores, mineralsand chemicals’

Alumina 3 5 0.6(21) Loader/conveyor Covered

Bauxite

Cement

Chrome ore

Coal

Coke

Gypsum

Ilmenite s a n d

Iron ore

Iron pyrites

Kaolin (chlna clay)

Lead ore

MagnesiteManganese ore

Nickel ore

PetrocokePhosphate (rock)

28 (dry)-49 (wet)

40’

3 5

3&45

3 7

4 0

30-50

40

3&3S

40

3 5

3wo3&34

0.8 (28)

1.1(39)0.7 (23)0 9-1.5

1.0 (34)

0.4 (14)

1.4(48)

2.4(85)

1.1(38)

1.2(44)0.4(13)

0.4(14)

0.7 (25)

1.1(39)

1.3 (46)0 4(13)

0.5 (17)0.7 (25)0.5 (17)

0.7 (23)

0.6 (20)Barr&0.7 (25) Package Covered

1.5(52) Unloader/conveyor Open1.0(34) Unloader/conveyor Open or closed Dust filter

Conveyor screw Totally Exclusion of motsture,and p”eumat,c enclosed dust filter

Drums, casks1.1(40)

CkWSS0.4(15)

Unloader/beltconveyorUnloader/beltconveyorUnloader/beltconveyor

Open

Open

Covered

For certain grades,fire precautions

Unloader/beltCO”“eyXUnloader/beltCO”WyOrUnloader/beltconveyorUnloader/beltconveyor

Open

Open

Open

Covered

Dust filter for certat”grades

ConveyorPackageConveyorConveyor

Covered

CoveredCovered

Cleaning of conveyorsand storage area nec-essary when aluminahandled after bauxiteat common facihtlesDust filter

Potash . . . . . . . . . . . . .

Salt . . . . . . . . . . . . . . .

Sulphur

Superphosphates

Foodsruffs andvegemble producrs:

A n i m a l m e a l sBananas

Barley

Citrus fruits

COCO8 1.9(6.7)

Coffee . . . . . . . . .Copra . . . . . . . . .

Cotton . . . . . . . . . . . . .

Deciduous fruts

Esparto grass

Flour

Grapes ..........

Maize . . . . . . . . . . . . .

Oats . . . . . . . . . . . . .

Oil seeds . . . . . . . . . .

Other vegetables 2.0(71)

Rice 1.5 (54)

Rye .................

Semolina . . . . . . . .

32-35

4 5

3&40

35-40

3 5

16-28

3c-40

3 2

3 0

0.9(33)1.0(36)

1.0 (37)1.1(37)

0.5(19)

0.9(31)

1.0(36)1.1(39)

1.5 (53)

1.5 (54)1.7(60)

1.8(65)2 1(73)

2.9(103)

1.3 (45)

1.4(441~ I

1.5 (54)2.1(75)

2.3(8.0)1.8(63)

2.1(74)

1.6(57)1.7(60)

1.4 (50)1.6(55)1.7(61)

Unloader/conveyor Closed

Barr&1.4(41)

CWi31.7(60)

Barrels1.3(47)

Cartons3.9(138) Pocket conveyor

ConveyorPackage

Cases, cartons,etc.

2.5(88) Package

Conveyor CoveredPackage Covered

Package CoveredConveyor Open

Package Open

CO”Ve)WPackage

CoveredCovered

Package Covered

ClosedCoveredCovered

CZNS2.5(87) Package

PackageConveyor

Bales2.7(94) Package

Cases, cartons.etc.

2.7(97) PackageBales

4.2(150) Package

Sacks, barrels1.6(55) Package

Cases, barrels3.9(140) Package

Co”veyor(pneumatic)BagsPackage

Cases. kegs2.0(70) Package

Cases. barrels,

1.61(57)

Cartons ,baskets,barrels2.7(95)

Kegs1.9(69)

2 1 0

Package

Package

Package

ConveyorPackage

Covered

Covered

COVeredCovered

Covered

Covered

Covered

Covered

Enclosed

Covered

Covered

Covered

Covered

Covered

Dust filter

HumidityControlled

Precautions againsthealth and fire risks

Refngeraticn

Cool store

Protectionfrom weevils

Cool store

ProtectIon fromvermin and weevils

Protection fromvermin and weevils

Protection fromvermin and weevilsProtection fromvermin and weevils

TABLE I (conrimed)

Protectlo” fromvermin and weevilsProtectIon fromvermin and weevils

Soya beans . . . . . . .

Sugar . . . . . . . . . . . . . .

Sugar, green .......

Sugar-beet . . . . . . . .Tapioca . . . . . . . . . .

Wheat . . . . . . . . . . . .

2 9 1 . 2 (44)1 . 4 (50)

3 2 1 . 3 (46)1 . 3 (46)

Conveyor Covered

Conveyor Covered

Baskets1.5 (52) Package Covered

Package OpenPackage Covered

3.8(135)1.5 (53)

25-28 1.3 (47)1 .s (52)

Conveyor Enclosed Protection fromvermin and weevils

Animal products:Bacon Cases

1.7(59) Package Refrigeration inhot climates

Butter Cases, CartOnS,kegs

1.7 (60) Package Covered

Conveyor OpenConveyor Covered

C&es1.7(60) Package Covered

Cases, cartons1.4(50) Covered

Refrigeration inhot climates

BonesBones, calcmed

Canned meats

Cheese

2.4 (84)2.8 (100)

1.8 (65)

Cool store

Cool store orrefrigeration

RefrigerationRefrigerationRefrigeration

Refrigeration

Frozen:BeefLambWhale-meat

2.6(92)3.2(115)

2.3 (SO)

Pocket conveyor EnclosedPocket conveyor EnclosedPocket conveyor Enclosed

CXtO”S2.1(75) Pocket conveyor Enclosed

Cartons, bales.bundles1.8(65) Package Covered or

open

Hides, wet

Good ventilation

Milk, dry or pow-dered 1.9(68)

Cases, cartons2.0 (72) Package

Cases, ca*ons,kegs

1.7 (60) PackageLOO%

5.2 (185) PackageB&S

4.2 (150) PackagePressed bales

2.5 (87) PackagePressed bales

1.4-2.5 Package(S&90)

Pressed bales

Milk, condensed

Covered

Covered

Covered

Covered

Covered

Skins, dry hides

WOO1

(kF=Y)4.2 (150) Package

Pressed bales(dumped)

0.5 (18) Package

Covered

Covered

F!sh products:Canned fish

Fishmeal 1.8(63)

CtWSS1.7(60) Package Covered

Package Covered

211

Fish oils ............

Frozen fish .........

Foresr products:Cork ................Hardwood .........

Paper ...............

Pit props and plywood

Plywood, chipboardRubber

Sleepers . . . . . . . . . . .Softwood . . . . . . . . . .

Wood-pulp ........

Memi products:Copper .............

copper c”“ce”trates

Ironandsteel

Scrap iron and steelTin

Tin plateZinc

Zinc mncentrates

Vehicles:Motor vehicles,

unpacked

Motor vehicles,knocked down

45

4 0

1.1(40) PipelineBarrels, cases

1.6(56) PackageBOX%

2.1(75) Package

4.2(150) Crane0.9-1.4 CGi”e(30-50)Rolls

2.5 (90) CIa”eBales

1.4-2.8 CP,“e(5SlOO)2.2-3.4 CIa”e

~,gE)~ Cra”eSheet

1.7 (60) CCi”=?Bales, bags

1.9 (66) Cra”eCrepe, cases

2.0(70) CIa”e1.3(45) Cra”e1.4-2.0 Cra”e(X-70)

Pressed bales1.7(60) Crane

Ingots0.3 (11) CE?“eCoils

0.9 (30) Cra”e0.5 (16)

0.7 (25)Slabs

0.3 (12) Crane

Pig-iron0.3 (10) CKi”e

Billets0.3 (12)

Bars0.4 (15) CIa”e

1.0(35)

0.6(21)

Steel plates0.3 (12)

Cra”eIngots0.3 (9) Crane

0.3 (12) CraneIngots

0.4 (15) CraneCrane

4.0-8.0 CM”t?(150-300)

1.0 (35)

Tank

Enclosed

Enclosed

OpenOpen

Refrigeration

Covered

Covered

Open

Covered

Covered

Covered

CoveredOpenOpen

Open

Covered

Covered

Covered

Open for short Provision forperiods drainage

Covered forlong-termstorage

Open

OpenCovered

CoveredCovered

Open

212

TABLE II

Discount factors

0 990100 980300.970600 960990 Y5147

0.980400.961170 942330 923850 90574

0.970880.942600.915150.88849D.862610.X37490.813100.789410.766420.744100.722430.70139

0.961540.924560.889000.854810.821930 790320.759920.730700.702590.675570.649590.624600.600580.577480.555270.533910.513380.493630.474650.456390.438840.421960.405730.390130.37512

0.95239 (1.943400.90703 0.89000

0.934580.873440.816300.762900.712990.666350.622750.582010.54394

0 925930 857340 793X40.735030 680590.630170 583500 540270.500250 463200 428890.397120.367700.340470 315250.29190

0.91744 0.909100.84169 0 826450.77219 0.751320.70843 0.683020.64994 0.620930.59627 0 5644X0.54704 0 513160.50187 0.466510.46043 0.42410

0.90091 0.892860.81163 0.797200.73120 0.711790.65874 0.635520.59346 0.567430.53465 0.506640.48166 0.452350.43393 0.403890.39093 0.360620.35219 0.321980.31729 0.287480.28585 0 256680.25752 0.229180.23200 0.204630.20901 0.182700.18830 0.163130.16964 0.145650.15283 0.130040.13768 0.116110.12404 0.103670.11175 0.092560 10067 0.082650 09070 0.073790.08171 0.065890.07361 0.05883

L

34

6’ . . . . . . . . .789

10 ..:....:”

0.863840.822710 7x353

0.839620 792100.747260.704970.665060 627420.59190

0 94205 0.887980.93272 0.870570.92349 0 85350

0.746220.710690.676850.64462Cl .613920.584690.55684

0 914350 905290 896330 887460.878670.869970 861360 852830.844380.836020.827750.819550.811440.803400 795450.787570.77977

0.836760 . X 2 0 3 . 50.804270.788500.773040.757880.743020 728450.714170 700170.686440 672980.659780.646850.634160.621730.60954

0.55840 0.508350.52679 0.47510

0.422420.387540.35554(1.326180.299250 274540.251870.231080.212000.194490.178440.163700 150190.137790.126410.11597

0.385550 350500.31864

1 1 .....1 2 . . . . . . . . 0 49697

0.468840 442310 417270.39365

0.444020.414970.387820.362450.338740.316580.295870.276510.25842

1 31 41 51 61 71 81 92 0

0.680960.661120.64187

0.530330.505070.48102

0.289670.263340.239400.217630.19785

0.623170.605020.587400 570290.553680.537550.521900 506700.491940.47761

0.458120.43630 0.371370.41553 0.350350.39574 0.33052

0.270270.250250.23172

0.179860 163510 148650.37690

0.358950.341860.325580.310070.29531

0.31181 0.214550.198660 183950.170320 157700 14602

0.29416 0.241520.27751 0.225720.26180 0.21095

0.135140.122850 1116X

‘1

2 22 32 42 5

0.24698 0.197150 23300 0.38425

0.101530 09230

TABLE III

Amortization factors

I 2 3 4 5 6 7 8 9

[email protected]

123456.789

1.01002 1.020010.50752 0.515060.34003 0.346760.25629 0.262630.20605 0.212160.17255 0.17853

1.03001 1.04001 1.05001 1.06001 1.070010.553100.381060.295230.24390

1.080010.560770.388040.301930.250460.216320.192080.174020.160080.140930.140080.13270

1.10001 1.110010.58394

1.120010.591700.416350.329240.277410.243230.219120.201310.187680.176990.168420.161440.155680.150880.146830.143400.140460.137940.13577

0.52262 0.53020 0.53781 0.545440.35354 0.36035 0.36722 0.374120.26903 0.27550 0.28202 0.28860

0.576200.402120.31548

0 409220.322330.270580.236380.212220.19433

0.218360.184600.160510.142460.128440.117240.108080 10047

0.22463 0.23098 0.237400.203370.179140 161040.14703

0.263800.229610.205410.187450.17365

0.19077 0.197020.16662 0.172830.14853 0.15473

0.209800.185560 16747

0.222920.198700.180680.166800.155830.146950.139660 133570.128440.124060.120300.117050.114220.111740.109550.107620.105910.104390.103030.10181

0.148630.130700.116750.105590.096460.088850.082420.076910.072130.067950.064260.060990.058060.055420.053040.050870.048890.047080.04541

0.154520.136520.12252 0.13450 0 14070 0.15349 0.18061

0.169810.161130.15403

1 01 11 2

0.111330.102180.09457

0.12330 0.12951 0.135870.11415 0.12039 0.126800.10656 0.11283 0 11928

0.142380.133360.125910.119660.114350.10980

0.162750.153970.14677

1 31 41 51 61 71 81 9

0.088120.082610.07783

0 094030.08X530.083770.079620.075960.072710.06982

0.100150.094670.089950.08583

0.106460.101030.09635

0.112970.107590.102970.09896

0.126530.121300.11683

0.14078 0 148160.13575 0.143230.13148 0.13907

0.135520.127820.124670.121940.119550.117460.115630.114010.11258

0.073660.069980.066710.063790.061160.058790.056640.054670.052880.05123

0.092280.088700.085550.082750.080250.078000.075980.074140.072480.07096

0.10586 0.112980.109630.106710.104130.101860.099840.098040.096430.094980.09368

0.082200.079000.076140.073590.071290.069200.067310.065590.06402

0.09545 0.102430.09236 0.09942

0.132480.129850.127570.125580.123840.12232

0 089630.087190.085010.083050.08128

0.096760 094400.092290.090410.088720.087190.08582

2 02 12 2

0.067220.064880.062750.06082

0.133880.132250.13082

2 32 42 5

0.12098 0.129560.11979 0.128470.11875 0.12750

0.059050.05743

0.079680 07823

0.111300.11017

1 104x0 150112 2236X 465733 24130 483604 42167 930935 37570 39975

01536 02011 Xl647 91646 69179 14194 6259025595 85393 30995 89198 27982 53402 9396522527 97265 76393 64809 15179 24830 4934006243 61680 07856 16376 39440 53537 7134181837 16656 06121 91782 60468 81305 49684

6 ,..789

1 0

77921 06907 1 1 0 0 8 42751 27756 5349899562 72905 56420 69994 98872 3101696301 91977 05463 07972 18876 20922x9579 14342 63661 10281 17453 1810385475 36857 53342 53988 53060 59533

11 .,. 2891812 6355313 0942914 1036515 07119

69578 88231 33276 7099740961 48235 03427 4962693969 52636 92737 XX97461129 X7529 X5689 4823797336 71048 08178 77233

7993669445334885226713916

16 ..I171 8192 0

51085 12765 51821 51259 77452 16308 60756 9214402368 21382 52404 60268 89368 19885 55322 4481901011 54092 33362 94904 31273 04146 18594 2985252162 53916 46369 58586 23216 14513 83149 9873607056 97628 33787 09998 4269X 06691 76988 13602

212 22 32 4 .,.25

48663 9124554164 5849232639 3236329334 2700102488 33062

85828 14346 091722 2 4 2 1 74103 4707005597 24200 1336387637 87308 5873128834 07351 1 9 7 3 1

30168 90229 04734 59193 2217825306 7646X 26384 58151 0664638005 94342 28728 35806 0691200256 45834 15398 46557 4113592420 60952 61280 50001 6765X

2 62 72 X2 93 0

81525 72295 04839 96423 24878 X265129676 20591 68086 26432 46901 2084900742 57392 39064 66432 84673 4002705366 04213 25669 26422 44407 4404891921 26418 64117 94305 26766 25940

313 2333 435

00582 0471100725 6988469011 6579525976 5794809763 83473

87917 77341 4220662797 56170 8632495876 55293 1898829888 88604 6791773577 12908 30883

35126 740x7 99547 8181788072 76222 36086 8463727354 26575 OX625 4080148708 18912 82271 6542418317 2x290 35797 05998

3 6373 83 94 0 ,..

91567 42595 2795x 30134 04024 8638517955 56349 90999 49127 20044 5993146503 18584 18845 49618 02304 5103892157 89634 94824 78171 84610 8283414577 62765 35605 Xl263 39667 4735X

414 24 34 44 5

98427 07523 33362 64270 01638 92477 60969 98420 04880 4558534914 63976 88720 82705 34476 17032 87589 40836 32427 7000270060 28277 39475 40473 23219 53416 94970 25832 69975 9488453976 54914 00990 67245 0x350 82948 1 1 3 9 8 4287X 80287 8826776072 29515 40980 07391 58745 25774 22987 80059 3 9 9 1 1 96189

4 64 74 84 95 0

90725 5221064364 67412OX962 0035895012 0837915664 10493

x3974 29992 6583133339 31926 1488331662 25388 6164293526 70765 1059220492 38891 91132

38857 50490 83765 55657 1436124413 59744 92351 97473 8928634072 81249 85648 56891 6935204542 76463 5432X 02849 1724721999 59616 Xl652 27195 48223

515 2535 455

16408 81899 04153 53381 7940118629 X1953 05520 91962 047397 3 1 1 5 35101 4749x X7637 9901657491 16703 23167 49323 4502130405 X3946 23792 14422 15059

21438130927106033132

5 6 16631 35006 85900 98275 32388 523905 7 96773 20206 42559 78985 05300 221645 x 38935 64202 14349 82674 66523 441385 9 31624 76384 17403 53363 44167 644866 0 78919 19474 23632 27889 47914 02584

3620734095

20969 99570 91291 9070052666 19174 39615 9950530680 19655 6334X 5862900849 74917 9775x 1637914110 06927 01263 54613

18602 7065971194 18738

320815700460672

568698437862300

90655 1505344013 4884069014 6004525331 1256608158 17983

21916 8182563213 210691 8 4 2 55867816439

849034494711458

44394 4288010634 1295242508 32307055x5 5694118593 64952

56865 05859 9010618663 72695 5218036320 17617 3001567689 93394 0151147564 81056 97735

31595 0154720847 12234OX272 84115

8559090511

2635X 85104X5977 29372

271562028574461

91610 7818833703 9032230613 7495229975 8986828551 90707

49442011887158523495

5390065255850306435046104

70960 6399064835 44919

51851

51132 019159473X 1775288916 19509

75601 4071905944 5515792747 6495135156 3574925625 58104

3042121524170121 0 3 6 732586

61666 9990415227 9690964161 1829607684 3618886679 50720

3281244592228511x51094953

14778 76797 14780 13300 87074 79666 9572581536 X6645 12659 92259 57102 80428 2528061362 98947 96067 64760 64584 96096 9825363904 45766 66134 75470 66520 34693 9044922209 71500 6456X 91402 42416 07x44 69618

4260793161599206977441688

4380876038298413361134952

76655 62028 7663065855 77919 8800680150 12777 4850154262 85963 0354737888 3x917 88050

555361 8 0 5 9

945955774038867

9973020542587272541756307

73211

6656689768328323793739972

2988006115206550992256873

281084413761607

848550200815475484184951X

29080 09250 7965673708 83517 3610356942 53389 2056225555 21246 3550989565 20103 77490

4656570663196614736341151

3172035931483732886546751

83035 92350 36693 3123X 5964997662 24822 94730 06496 3509088824 71013 1x735 20280 2315312544 41035 80780 45393 4481222716 1 9 7 9 2 099x3 74353 08668

427918733820468

04102 46880XXX63 777757282X 00102

18c62

46634 0654114222 60697

4570969348667949780959583

5622X237267x5476273032261

41546519008178892277X5653

72772 0233886774 9828935165 4304098931 9120270735 25499

57375041104557X1477722923

917540482272924

4196160383

1 2 5 1 530429

X2732 38480 72817 3252335083 19687 1 1 0 5 2 9 1 4 9 135970 19124 63318 2968676554 31601 1 2 6 1 4 3307272152 39339 34806 08930

16815 69298 4443719746598469232587820

2436900697

542243555275366

033876033285CQl

6475X37680

214

6162636465

03931 333097442h 3327X09066 UU9U342738 1243616153 08002

57047 7JZll 63135 17361 h2825 3Y90R 05607 ')12x443972 IOIlY XYYI7 IihhS 52872 73823 ??l?J XXhh220795 954F2 Y2648 45454 0'1552 88815 I h5ii 51125X7025 14267 2OY79 (I4508 64535 31355 I(h(lh4 a47226504 41744 XIY5Y hSh42 74240 56302 UMJ33 67107

6X833 75570 3Xh‘lK Jh920XRY70 7-M')? 51X05 W37X74375 Y7596 162Yh bb(lY247689 U51174 5246X IhX3477510 7Cl625 28715 11191

6667686970

21457 4074221.581 5780255612 7809544657 6699991340 84979

21840 LSO35 34537 33310 Oh11617621 471175 -1208(1 Y7403 4U62h

Y5240 15Q57 36572 MO0408995 43X05 33386 31597XX525 427X6 U526Y Y'53293Yll 25650 126X2 73572XY2U3 71795 Y9533 50501

71727 37475

91227 2119950001 38140653YO 0522427504 9613137169 94851

29820 967X3 2Y4UUw5u 89728 17Y3783197 33732 05810YY324 51281 844h346949 81973 37949

31935 27022 840676632 1 1YY24 7216372958 2860') X1406li3944 41575 1057339117 XY632 OOQ59

24813 XOYOZ 60397 1648Y 03264hU543 79312 93454 6X876 25471OlU13 43997 15263 X(lh44 43442

05462 35216 14436 29X91 68607UYS38 12151 06878 YlYU3 187493Y147 25549 4X542 42627 45233

41867 14951 Ylh96 8506534405 560X7 827YU 7092557202 W617 23772 I17896

OK619 64482 73923 36152 05184 Y3142 2529Y 84387 3492516487 h5536 4YO71 39782 170Y5 02330 74301 UO175 4X280

76 1150877 3744978 4651579 3098680 63798

70225 51111 38351 lY44430362 06694 54690 0405270331 85922 38329 5701581223 42416 58353 2153264995 46583 09785 44160

hh4Y9 71Y4553115 6275715765 9716130502 3230578128 839Yl

05422 13442 7X675 8408195348 78662 11163 8165117869 45349 61796 6634586482 05174 07901 5433942X65 92520 X3531 80377

8182838485

82480 84846 99254 67632 43218 50076 21361 64816 51202 88124 4187021885 32906 92431 09060 64297 51674 64126 62570 26123 05155 591946 0 3 3 6 98782 07408 53358 13564 59089 26445 29789 85205 41001 1253543937 46891 24010 25560 86355 33941 25786 54990 71899 15475 9543497656 63175 89303 16275 07100 92063 21942 18611 17348 20203 18534

8687888990

03299 01221 05418 38982 5575879626 06486 03574 17668 0778585636 68335 47539 03129 6565118039 14367 61337 06177 1214308362 15656 60627 36478 6564X

92237 26759 21216 98442 08303 5661376020 79924 25651 83325 8842811977 02510 26113 99447 6864546609 52989 74014 64708 00533

8507634327

36764 53412

12856 6622727698 9x20402753 1482714186 0082176123 SO842

79180 9752636692 4020217349 8829890053 x953443772 39560

09013 07832 41574ii39817639

9192939495

79556 2906892608 8267423982 2583509915 9630659037 333cil

04142 16268 1538727072 32534 1707540055 67006 1229305908 97901 2839526695 62247 69927

96979899

loo

42488 78077 69852 61657 3413646764 86273 63003 93017 3120403237 45430 55417 63282 9081686591 81482 52667 61582 1497238534 01715 94964 87288 65680

38358 22478 73373 88732 09443 82558 0525063863 11951 34648 88022 56148 3492s 5703123235 35071 99704 37543 11601 35503 8517180703 70426 75647 76310 88717 37890 4012943834 86654 70959 79725 93872 28117 19233

43092 04098 73571 80799 76536 71255 6423935275 57306 55543 53203 18098 47625 88684901R3 36600 78406 06216 95787 42579 9073076036 49199 43716 97548 04379 46370 2867212918 86537 62738 19636 51132 25739 56947

6693850425

43653349714Y10674X18ii 1250

iY894529247986061075

5886135QOY

469425423R

52689 5127552799 2822512133 14645

8355685762235411958580136

7592850585934484790875567

9822703X62

2182478095

9151172811 2271715152 5523058408 1326182163 60859

215

Annex II

MATHEMATICAL TECHNIQUES

A. Monte Carlo risk analysis Gangs per ship per shift probability

1. The Monte Carlo technique is a procedure for obtaining approxi-mate evaluations of mathematical expressions, consistmg of one ormore probability distribution functions. In essence, the techniqueconsists of simulating an experiment to determine the overall statls-tical properties of a system by the random sampling of each compo-nent of the system. The actual takmg of a physical sample from thereal system is either Impossible or too expensive and thus simulatedsampling must be used. Simulated sampling involves replacing theactual component distribution by a theoretical assumed probabilitydistribution, and then samplmg from this theoretical distribution bymeans of a random number table.

2 . The technique has wide practical applications and can be usedfor risk analysis when various investment alternatives are beingevaluated. In the matter of port development. future events areprobabilistic. For example, the planner does not know for certainthat in three years’ time the terminal will have to handle I milliontonnes of break-bulk cargo. He may know that there is a high prob-ability that the volume of cargo will be not less than 800,000 tonnesand not more than 1,400,OOO tonnes. Thus, the future terminalthroughput can be described in terms of probability distribution func-tion. Other elements, such as productivity and gangs per slup pershift can also be described by probability dlstribuhons. With esti-mates of these distributions, the Monte Carlo technique may be usedto evaluate the performance and cost associated wth various invest-ment alternatives.

5 . If the planner now requires to find the Joint probability distri-bution of the berth-day requirement he must carry out, either byhand or by computer. the drawing of random numbers to represent alarge number of possible outcomes of each of the three parameters.

6. For traffic demand, the five different tonnage ranges areassigned the set of numbers chosen from l&99 which goes them theappropriate range of probability.

P~Ob~b,h” Nllnibari-onnes plicEni”@ rangr

400 000-600 000 (15) O&l4600 000400 coo (20) 15-34800 COO-1 million ., .,., ., (30) 35-64l-l.2 nullion (20) 65-841.2-1.4 million ..,. (15) 85-99

3 . The probability for the occurrence of any given combmation asthe result of the throwing of a par of six-sided dxe IS made up of theseparate probabilities for the occurrence of each face of each indi-vidual dice. Where the Individual probabihties are equal, as would bethe case for unbiased dice, it is possible to calculate the joint probab-ilities. But where the individual probabilities are unequal and un-known-If the dice were biased, for example-the calculation is notpossible and It is necessary to carry out an experiment to estimate thejmnt probability. The drawmg of numbers from random numbertables like the one given in annex I is a form of experiment.

4. The technique as applied to port planning can best be illus-trated by a numerical example. Let us suppose that a planner hasarrived at the following statistical estunates for a berth group in theyear 19x5:

The productivity probabilitxs are allocated numbers similarly:

Tomm PIObOhlll*y Mm&vper how p<?Ce,i,O&V ‘O,QP

8-12 ,.. ., (40) O-3912-16

r;oo;4G79

l&20 8&99

Finally, the gangs per ship per shift probabilitxs are allocated num-

bers:

Traffic demand probability

400 00&600 000 15600 00&800 000 2 0800 000-I million 3 0l-l.2 milhon 201 . 2 - 1 . 4 mdlion 15

Nun,ber Of Probnbibry Number&=w percrnrngr ‘“qe

2 (20) &I93 2S694 i::; 70-99

7 . The Monte Carlo experunent now proceeds by drawing a set ofthree random two-chgit numbers-say the first two digIts of the firstthree numbers in the column (I) of annex I, table IV, namely, 10, 22and 24. The number 10 lmphes a tonnage of 400,00~600,000 tonnes;22 implies a productwity of 8-12 tonnes per hour; 24 implies 3 gangs.A calculation for the first sample set of data is now carried out (usingthe mid-range figure to represent tonnage and tonnes per hour, andassuming a fixed fraction of time worked per day of 0.6).

Berth-day requirements= 500,000 tonnes10 tons/hour x 3 gangs x 0.6 x 24

Productivity probability = 1.157 berth-days

Tonnes par prig horr, PerCe”i”,gC

8-12 .., .., 4 012-16 ., .., 4016-20 20

8 . This single figure of 1.157 is recorded as the result of the firstsample and the process is repeated-perhaps 50 to 100 times-to givea new probability distribution which can be drawn as shown in figureI, and which will be of interest to a decision-maker. The decision maythen be taken that it 1s reasonable to plan for the 90 per cent berth-day requirement probability, i.e. 3,000 berth-days.

2 1 6

Cumulative probabilit) distribution for Monte Carlo numerical example

0 1000 2000 3000Berth-day requirement

4000 5000

Y Thx procedure would normally be carried right through to themore easily understood decwon measurement of the net presentvalue of the investment proposal, and m that cnbe a computer pro-gramme to carry out all the calculations would be justified Howeverlaborious such a procedure is. It is always porsible to do it manuallyand it may be more attract,\e to set a student to work on this for afortmght than tog” to the expcnae and trouble ofcompute~ program-ming. The queuemg curves mcorporated m the plannmg charts can beused to calculate the writing-times. and m fact the plannmg chartscan also be used to calculate the berth-days for each sample of ton-nage, productwlty and gangs per shift.

12. The followmg general pants should be borne in lnmd whenconsidermg the use of computer simulation rechmques:

(a) Slmuiatlon gives the model‘s response to a given Situation;

(b) Simulation 1s a useful trammg aid and an excellent method forresearch into system behaviour:

(cl Slmuldtlon allows many alternatives to be tried.

(d) The cost of simulation may affect the decwon whether or notto use the techmque:

(e) Simulation development costs are difficult to forecast accu-rately;

B. Simulation

1 0 . Simulation 1s a branch of modern management science and isa technique for modelhng a complex process wlxch would otherwisedefy mathematical descripuon, because of the stochastic” behaviourand non-lmear characteristics of the process. In simulation. the sys-tem is broken down into a number of subsystems that are far& easyto describe mathematically. These pars are then combined to give amodel of the whole system, and then responses to various mputs canbe measured. The parameters of the model can be varied, whichenables the user t” snnulatr proposed changes to exlstmg or futureprocesses and hence evaluate the economics of various alternativeswithout costly cap&d investment.

cf) General mod& that can be applied without modiflcatmn willnormally provide only linuted informatron,

(gl Very often, the formulation and “debuggmg“ of the model wllsupply the answer wthout the need to run the model.

13. Although the use of simulation for port development wasrecommended in a prelimmary report hy the secretariat as a methodof pracrical value. it was noted thar the method can be used only mcases where adequate statistIca data are available.h After subsequentresearch and apphcatmns of the method.’ the secretariat was able tospenfy the follo~mg prereqmsites to ohtammg the full hensflts fromthe techmque:

1 1 . Because of the large number of reperitwe calculatmns and thevolume of data involved m a SLmulatlon model. many models are runon a computer. For tlxs reason, various simulation languages havebeen developed to allow more rapid implementanon of the conceptual model into a workmg model The most commonly used lan-guages are:

GPSSSIMULACSLSIMSCRIPTSIMONGASP II

(oi Accurate and precrse traffic forecasts and future cargo hand-hng rates;

(b) Expertw in simulation methods. both in model developmentand ,n model use;

(c) Sufficient time to allow for dam collccnon, model defimtion,documentatinn. programmmg. tesimg and vahdatmn. followed by aperiod to obtain results from the model for various mvestment altsr-natives.

II. In many cases these condrtmns will not apply to port plannmgin developmg countrxs. This war the reason for the development ofthe plannmg charts described in this publicarion. In the majority ofcasts. these charts are more appropriate than simulation.

In addmon. non-slmulatlon languages can also be employed. andmodels are often developed usmg computer languages such as FOR-TRAN, COBOL, ALGOL. PASCAL and PLil.

217

Comparison of total tonnage distribution for correlated and uncorrelated cases

l.O- - 1.0l-a

2 Correlated traffic streams2 0 .9 -

;---A_ 0.9

- - - - - - - - Uncorrelated t r a f f i c s t r e a m s1

-0 ,;

E 0.8- - I 0.8t; 1---a5 0.7 - _ 0.7sj 0.6 - - 0.6

z 0.5 - - -2

0.5II8 0.4 - I_ 0.4r-ds 1i- 0.3 - - I‘i; i

0.3

t 0.2 - - - 0.2zBo”O.l-

--__ r:-

:’0.1

Lzo - .-m-,1- 0I I I I , , / I, I I I I / I, I I I I,

100 150 200 250 300

Annual throughput (thousands of tons)

C. Combination of traffic class uncertainties

15. The detailed analysis of traffic, category by category androute by route, is to some extent wasted unless a satisfactory methodexits of recombining them mto the aggregated traffic of a berthgroup, tar it IS only at this level that performance calculations can bemade.

16. A numerical example is used to illustrate the techmque ofcombinmg traffic forecasts into an aggregate berth group traffic fore-cast. It is assumed that a terminal is to ~ecave three different classesof traffic. The tonnages and probabllmes for each traffic are forecastas shown in table V.

17. When the various traffic streams are independent, the jointprobability is gwen by multiplying the individual probabibtiestogether for each combination. Thus the probability of the highestforecast, namely, 250,000 tons. being fulfdled is 0.2 x 0.3 x 0.1 or0.006. while the probability for the lowest forecast, namely, 110,000fO”S, IS 0.3 x 0.1 x .rJ12.

1 8 . Table VI tabulates the various combinations and the proba-bihry of their occurrence The independent nature of each trafficstream smooths the demand on the berth group. However, when suchseparate forecasts are interdependent or, m mathematical terms, cor-related, the combmed probabllitles will be different. When one factoris completely dependent on or correlated wth another, then it is saidto have a correlation coefficient of 1.0.

19. For completely correlated traffic, the probability of the high,medium and low forecast for the numerical example given abovewould be 0.2. 0.533 and 0.267 ’ The expected volume of traffic isgiven by:

250 X .2 + 180 X ,533 + II0 x ,267 = 175.3 thousand tons,

as compared with the expected volume of traffic for the uncorrelatedcase of 177.78 thousand tons. Thus the factor of correlation affectsthe distribution in this case rather than the expected value. Thecumulative probabdity for the two cases is shown m figure II. For thisexample. the throughput which would have only a 10 per cent proba-bllity of bang exceeded would be 205,000 tons for the correlated casebut 250,000 tcm.s for the uncorrelated case.

2 0 . Attempts to estimate the optimistic and pessimistic values ofeach separate category as well as their most likely values are notnormally justified, since the combination of these estimates is itselfsensitive to estimates of the degree of correlation between the varioustraffic categories, and these correlation coefficients wll seldom besufficiently accurately known. Instead, the estimates should belimited to the central, most likely, value of each category, with theassumption that the overall trend of the aggregated traffic will applyequally to each.

21. The exception to this will be where particular categoriesclearly have a range of uncertainty which is substantially differentfrom the overall uncertainty. In that case, the difference from thetrend may be separated, combined with the differences in other cate-gories accordmg to whether these are independent or correlated, andthen added to the aggregated estmmtes.

2 2 . However. these mathematical refmements are unlikely to addmuch accuracy to the final estimates and they bring their own dangersin giving an appearance of precision which is unjustified. It is moresatisfactory to deal with uncertainty in a more practical way. Forexample, where wthin the context of an average annual growth rateof 10 per cent in a particular traffic, there is a possibihty for each oftwo routes, that the growth will be higher than the average, theplanner will be forced to contemplate the future picture or scenariowith both such extraordinary trends. To make his scenario consistentand reasonable he will need to consider the extent to which the twoabove-average trends can coexist. He should be able to arrive a~ acommon-sense way of synthesizing the overall traffic which in realitywill be as accurate as the mathematical way, and much more con-vincing.

TABLE V

Terminal cargo traffxc forecast and probability

A 1001.2 75/s 501.3B 801.3 60/.6 401.1c 701.1 451.5 201.4

218

Combinations of traffic forecasts and probabilities

M M H 205 .0x1M M M 1X0 ,150M M L I55 .I20M L H 185 005M 1. M 160 ,025M L L 135 ,020L H H 2 0 0 .1)09L H M 175 .I)45L H LL M HL M M

150 ,036I80 ,018I55 0911

L M L 1 3 0 072L L H 160 0 0 3L L M 1 3 5 015L L L 1 1 0 012

lO.SO

,9254.02.7IU7.8755.403.24

13.959.36II JR2.035I 32

1 OO(1 177 7x

Summary of analysis of port data collected for congestion surcharge study

Mombasa1 9 7 01971 . . . . . .1 9 7 2 . . . . . . . . .

Khorramshahr19711 9 7 21 9 7 3

Dar es Salaam1 9 6 91 9 7 019711 9 7 2

1 9 0 2 122 1 8 0 1 9 . 6 0 21 9 7 2 438 1 4 8 1 6 . 4 3 21 9 6 2 179 1 2 0 1 8 . 2 0 2

1 4 31351 2 3

1 4 41 4 41 4 4143

2 617 121 21 S6 32 747 1 2 6 21.88 33 718 1 3 3 27.86 3

I 3 7 7 8 2 1 6 . 8 9 22 027 1 1 9 1 7 . 0 1 7

2 186 1 5 7 1 3 . 8 9 21 833 1 3 5 1 3 . 5 9

D. Statistics of ship arrival. service distributions and waiting timethe service or berth time distribution. The servicing operation can beregarded in the following way There are two “stages”. not necess-

2 3 . UNCTAD research has confumed the widely accepted wewarily with a physical significance, each with an Erlang 1 dxtnbutlon.

that the arrival pattern of break-bulk ships ts best approxlmatcd by aWhen the first stage 1s completed the second stage is immedntely

Poisson dlstributmn. Thts 15 equwalent to the dlstributlon of the I”-begun. The total service tune then has the dlrtributlon of the sum of

terval between arrwals bang approxtmated by a negative exponentialthe two Independent random variables and may be represented by an

or Erlang 1 dtstnbutmn. As an example, the probablhty dlstributmns Erlang 2 dlstributlon.

for the case where one ship arrives every two days IS shown m figure 25. When the number of “stages” approaches a very large num-III. her, 1.e. gwing a high Erlang number. the serwce time tends to be

constant. but It 1s necessary for the Erlang number to be very high2 4 Based on data available to the UNCTAD secretariat (see before thts occurs. since the ratio of mean to standard dewation IS

table VII), the deasion war taken to use an Erlang 2 dlstnbution for gwen by the square root of the Erlang number.

219

FIGURE III

Arrival pattern of break-bulk vessels with an average ofone ship every two days

26. At the other extreme, the Erlang 1 distribution for the servicetime distribution would result in a large number of se~ice tunes

clustered together at zero. While this is a plausible presumption forship inter-arrival time, it is unreabstic to apply this presumptmn toslup time at berth. A comparison of the Erlang I and 2 cumulativefrequency distributmns for a mean serwce tnne of five days is shownin figure IV.

2 7 . The application of queueing theory can be used to g ive a goodapproximation of the waiting time for various system capacities. Thequeueing system modelled for a break-bulk berth group is based onthe assumptmns of random arrivals and an Erlang 2 service distribu-tion. In queueing theory notation this is the MIE,ln system (M forMarkovian or random arrivals, EZ for Erlang 2 serwce time and II fornumber of servers). The MIEJn system is very cumbersome math-ematically and has not been completely described for cases when n >2. Fortunately. it is possible to use an approximation suggested inPage’s book on queuang theory,’ which in most practical cases gweswfficxntly accurate results. Table VIII gives, for the M/E,ln system.the average waiting time of vessels in the queue, in units of averageservice time. These results have been used m the break-bulk planningchart II to define the relationship between berth utilization and totalship time in port.

2 8 . For speciabzed terminals the assumption has been made thatdlstributlon of the intervals between arrwals is best described by anErlang 2 distribution rather than by the negative exponential distribu-tion. This IS due primarily to the fact that a limited number of oper-ators uses each specialized terminal, with the result that there is some

E E. Page, Quewmg Theory I,L OR (London, Buttcrworths, 1972)

rationalization of arwals. The assumption of Erlang 2 distributedservice times here will give lxgher estimates of queueing time thanwould be expected far a terminal where ship turn-round was nearlyconstant. but from data available to UNCTAD the latter is rarely thecase. In those cases. particularly in vertically integrated bulk opera-tions, where shiploads are fairly constant, high Erlang numbers of 8or more have been used.

2 9 . Table VIII quantifies the relationship between wutmg timeand berth utibzation in units of average service time. As an example,a comparison of waitmg times for a four-berth terminal for the threequeueing systems (IV/M/~, MIEJ4 and E,/Ez/4) i s shown in f igure VThe sensitivity of waltmg time results to the assumed distribuhonshould be noted and borne m mind when evaluat ing alternatwes. TheM/E,In system is considered the best estimate of queueing tune forbreak-bulk termmals while the E,iEJn system is best for specializedterminals.

E. Mathematical basis for planning charts

3 0 . The mathematical relationships used to produce the curves ineach quadrant of the planning charts are presented below. With thisinformation the planner can reconstruct the curves to a differentscale.

Tons per day per gang = average number of tons per gang-hour xoverall fraction of tune berthed ships worked x 24

Tons per ship per day = tons per day per gang x average numberof gangs employed per ship per stuft

Berth-day requirement = annual tonnage forecast/tons per slnp

day

Approximate number of berths required = berth-day require-ment/(comrmssmn days per year x typical berth utilizatmn ).

(b) Break-bulk grnerd cnrgo rermnnl, pinnnirlg chnrr II. ship cm

Berth-day requirement per berth = berth-day requtrementlnum-ber of berths

Berth utilizatmn = berth-day requirement per berth/commissiondays per year

Total time at port (days) = 365 x number of berths x berthutthzation X waiting tune facto?

Annual ship cost = total time at port x average daily ship cost (inportj.

(c) Break-bulk general cargo remind, planning chari 111: storagearm reqrlirements

Holding capaaty requrred (in tons) = annual tonnage throughstore X average transit tune (days)/36Th

Net holdmgvolume required = holding capacity required/densityof cargo

Gross holding volume reqtured = 1.2 x net holding volume re-quired

Average etackmg area required = gross holdmg volume required/average stackmg height

Average storage area required = 1.4 x average stacking arearequired

Design storage area = average storage area required x (1 +reserve capacity safety factori100).

‘The berth utihzation f%gures used for 2, 3.4,5,6. 7.8, 9 and IO berths wereSO. .53, .60, 62, .65, .68. 69. and 70 respectively.

g The tactor IS 1 0 plus the average waitmg rime of ships ,n the queue Ml&,,,(in units of average serwce rime), as given in table VIII. This total ume includesboth berth t ime and queuemg time.

’ The number of times cnntents of store are turned over during one year isequal to 365 drvlded by the average transit time.

220

TABLE VIII

Waiting-time factor. Average waiting time of ships in the queue M&/n expressed in units of average service time

/Rundom arrrrwl~. Erlang I-durribrried srr”tce lime,

“,t,‘io,,“n , 2 i 4 F 6 7 d 9 10 1, I2 13 ,.I is

0.30u.310 . 3 20.330.340.350.360.37 :.:.0 . 3 80 . 3 90 . 4 00 . 4 10420 . 4 30.44u4s ..,. ,.0 . 4 60.470.48 ..,.0 . 49 .,. ,.,0.500.510 .52 .._...0 . 53 .._...054a.550 .56 .._...0.570580.590 . 6 00.610.620.630640.650.660.670.68 ..,....0.690.700.710.72 ..,...,0.730.740.75 _0.760 . 7 7 ..,.0.780.790 .80 .._.0 . 8 1 ..,.0.820.830.840.850.86 .,.....0 . 8 7 .,.0.88 .I.....0.89 .I._...0.90

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.43 1 2 .05 .03 .O?

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.46 .13 0 5 0 3 .02

.4x 1 4 .Oh .03 .O?su .I5 .Oh .03 .02.52 .16 .06 0 4 0 2.54 .I6 .07 .04 .a2.56 .17 .07 .04 .03.59 .18 0 8 .04 .03.hl .19 .0X .05 .03.64 .20 .09 .05 .03.66 .21 .09 .05 .w.69 .23 .lO .06 .M.72 2 4 .11 .06 .04.74 2s .12 1 0 7 .04.7s 2 6 .13 .07 0 521 .28 .13 0 8 0 5.84 .29 .14 .08 .05.88 .31 .15 .09 .06.Yl 3 3 .I6 .I0 .06.95 .35 .17 .I1 .07

1.00 .37 .18 1 1 .071.04 .39 .19 .l? .081.08 .J2 .20 1 3 .081 13 .44 22 .14 .091.18 .47 .23 .15 1 01.23 .49 .25 .I6 .I11.29 .51 .27 .I7 1 21.34 .53 .29 .19 1 21.40 .60 .3l .?O 1 31.48 .63 3 3 .22 .141.55 .66 .36 23 .161.62 7 0 .38 .25 .171.70 .72 .42 .27 .191.80 .78 .44 .29 .201.90 .83 .48 .31 .221.99 .87 .51 .34 .242.OR .93 .54 .36 .262 .X 1.00 .59 .39 .2x2.31 1.08 .63 .42 .302.46 1.16 .68 4 5 .332.59 1.23 .73 .49 .362.75 1.30 .79 .53 .402.95 ,140 .84 .57 .433.17 ,150 .92 .63 .473.45 1.70 .98 .68 .523.75 1.85 1.08 .74 .574.10 1.90 1.16 .81 .644.40 2.05 1.28 .90 .704.75 2.20 1.40 .98 .765.20 2.40 1 52 1 .07 .845 60 2.60 1.68 1.16 .926.10 2 85 1 83 1 .29 1.016.60 3.20 2.00 1 .43 1.12

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221

-.

FIGURE IV

Comparison of Erlang 1 and Erlang 2 distributions for an average vessel service time of five days

------- .6r!mg ,

- &long 2

T A B L E I X

Average waiting time of ships in the queue E,/E,/n

(In unirs of average service rime)

0.10 ,...0 . 1 50 . 2 00.250.30 .,,0.350.400.450.500550 .60 .,..,,,.0.650.700.750.800.850.90 .,. .,,

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(d) Container rerminnl, plnnnmg chart I: container park area

Holdmg capacity required (in TEUs) = contamer movementsper year x average transit time/365’

Net transit storage requirements = holding capacity required xarea requ,rement per TEU (square metres per TEU)’

Gross transit storaee area requirements = net transit storaeearea requtrements&io of a&age to maximum stacking heiglht

Container park area = gross transit storage area requirements x(1 + reserve capacity safety factorl100).

(e) Confainer ~ermmd, planning chart II. conminer freight s&on(CFS) nrea

Holding capacity required = CFS container movements per yearx average transit timei365’

CFS stacking area = holding capacity required x 29k averagestackmg height of general cargo

CFS average storage area = CFS stacking area x (1.0 + accessfac:o:)

’ Arca requremenr is dependent on operatmnal method and maxmunstacking hclght

*The cubic capaoty of an LSO container of the IC type IB 29 m’. The chartassumes that all containers are full.

222

F IGURE V

Graph showing relationship between average ship waiting time and berth utilization

CFS destgn storage area = CFS average storage area X (1.0 +reserve capaciry safety factor/lOO’)

(f) Conrmner lermmal, planrung churl III. berth-da) requiremenrUmts per day per crane = standard shtp operating hours per dayx average units per hour”

Units per day per berth = units per day per crane x gantry-cranefactor”

Average berth time per ship (in hours) = 24 x average number ofmoves per ship/units per day per berth + berthmg-deberthmgdelay”

Berth-day requirement = average berth tnne per ship x numberof ships per year124.

(g) Contamer ierminal, planning chart IV: ship costBerth-day requrement per berth = berth-day requirementlnum-ber of berths

Berth uttlizatlon = berth-day requrement per berthlcommisslondays per year

Ship tune at port = 365 x number of berths x berth utilization xwaiting time facto+

Annual ship cost x ship tune at port x average daily ship cost (inport).

(h) Dry bulk cargo rermmnl, planning charr I: berth ivne

Ship-loader (unloader) effective capacity (tons per hour) = shop-loader (unloader) rated capacity x through ship productiwtyratio

Through ship gross loadmg (unloadmg) rate = ship-loader (un-loader) effective capacity x ship-loader (unloader) berth con-figuration facrorq

’ The sakty marg,n factor has been apphed both to access arca requlrementrand to stackmg area reqwements.

m Id le nmc durmg standard stup operatmg hours per da, I\ included xn t h eun,ts per hour producwry factor.

” For one crane a, one bcrtb. factor $5 1 0. for mo cranes 1 8: and for threecranes 2 4

” A typical berthmg-deberthmg dcia) would be 2 0 hours. and thus figure hasbeen mcurporated ,n the chart

q the factori for 1. 2. 3. 4 and 5 shlp-loadcrs (unloaders1 per berth are 1.0,1 75. 2.25. 2.60 and 2 85 rerpectwely

(1)

Through ship net loadmg (unloadmg) rate = through ship grossloadmg (unloadmg) rate x standard ship aperatmg hours perday124

Average berth time per ship (m hours) = average shipment aze/through shop net loading (unloadmg) rate + berthmg-deberthingdelay.’

Dry bulk cargo rertmnol. piannmg charr II: shy COSIBerth-day requnwnent = average berth time per ship x numberof shtps per year/24

Berth utilization = berth-day requlrementlterminal comnuss~ondays per year’

Shtp tune at port = 365 x number of berths x berth unhzatlon xwa,t,ng-tmle factorP

Annual ship cost = ship tune at port x average dally ship cost (mport ) .

(j) Dry bulk cargo rcrminal, planning chart Ill- stockpile dlmen-smnwIgMaximum height = 0.5 x base x tan z

Maximum cross-secttonal area = 0.5 x base X maximum haght= 0.25 x base X base X tan x

Cross-sectional area = ratio of stockpile height to maximumheight x (2.0 - ratio of stockpile hetght to maximum height) Xmaxmum cross-sectional area’

’ A typical berthmg-deberthing delav wou ld be 2 0 hours and thus figure hasbeen mcorporarcd >n rhe chart.

’ A terminal wth two berthmg locatmns each able to berth ships 300 days 0fthe year wou ld have 6W termmal c~mrrussmn days per year.

Thor formula is derived as follow

h”= angle of repose= he ight of stockpIle

b = base of stockpxleL. = maximum height stockpnle can attam

r4= ram of h to h,.,= ~ross-~e~ti~nal area of stockpde

Am. = maxm~uni cross-secl~onal area of stockpile

The cross-secl~onal area of the stockpde 1s gwen by

A = (b-/z cotan a)h or A = (b-rh,,, cotan a)&,,,Subsututmg U.5 b tan CI for the first h,,, term gwes:

A = (b-r(O 5 b tan a) cotan a)&,,= r-(2-r) 0 5 bh,,,

B”,

Therefore

A,,, = 0 5 b/t,,,

A = ,(2-r) A,,,

223

Volume = cross-sectmnal area x length

Capacity (in tons) = volumelstowage factor.

(k) Roiro remind planning chart: vehde storage men

Vehicle holding capacity required = vehicle movements per yearx average transit time/365

Vehicle parking area = vehicle holding capacity required x arearequirement per vehicle

Vehicle parking and access area = vehicle parking area x (1.0 +access factor)

Vehicle storage area = vehicle parking and access area x (1.0 +reserve capacity safety factor/lOO.O).

F. Economic life calculation

3 1 . To determine the economic life of a prece of equipment re-quires the calculation of the discounted value of all future costs asso-ciated with each replacement policy. In general, the costs to be in-cluded are all costs that depend upon the age of the machine. Coststhat do not change wth the age of the machine such as labour costsand power need not be considered. The costs are incurred over aperiod of time. and must be discounted to the present m the normalw=Y

32. The assumption is made that costs increase each year foritems of equipment that deteriorate because of increased mainten-ance. For this assumption it can be shown that the following rules forminimizmg costs apply:

Rule 1: If the cost of replacing every n + 1 years is less than the costof replacmg every n years, the item should not be replaced.

Rule 2: If the cost of replacing every n + 1 years is greater than thecost of replacing every n years, the item should be replaced.

The mathematical justlficatmn of these rules is as follows.

3 3 . We may take a one-year period and call it i and the costsincurred during that period C,. We may assume that each cost is paidat the beginning of the period in which it is incurred, that the inmalcost of new equipment IS A, and that the cost of money is I perperiod.

3 4 . The discounted value K,, of relevant future costs associatedwith a policy of replacing equipment after every n years is given bysumming the discounted costs for the first pxce of equipment withthe discounted cost for the second piece of equipment, etc., or, ex-pressed mathematically:

GK,=A+C,+-+ G G1+r (l+r)2 +...+ (1 + r)R-’

+ A+C,(1 + I)” + (1 + $+1 + + C”

(1 + +--

+

which is equwalent to

The right-hand side of the equation may be written as a product ofthe common factor and the convergent geometric series.”

Therefore

nA + 8 [Cj(l + 7)’ - ‘1

K,= I=11 - [l/(1 + $1”

If K, is less than K, + , then replacing the equipment every n years ispreferable to replacing every n + 1 years. The two inequalities

Kn + , > K, and K,, _ , > K,

must hold if the best policy is replacement every n years.

3 5 . A worked example is given in table X mr a fork-lift truck.The annual cost shown in the second column would be based onmaintenance and operating costs from historic records. The thirdcolumn shows the discount factors for a rate of interest of 10 per cent,For this example the optimum replacement period or economic life isseven years. This can be determined by examining the last column.The estimated maintenance cost for the yearn + I is used to calculateK n 7 1 . IfK + 1 is greater than K, then replacement should takeplace after n years, which for this example is seven years.

3 6 . The existence of inflation will modify the weights” but themethod will remain the same. In addition, if the piece of equipmenthas a scrap value, the initial cost of new equipment can be reducedaccordingly.

“The sum of the series 1+x+x2+... +x= 1s equal to 1/(1-x), when x is lessthan 1 and positive. In this case x IS equal to I/(l+r)“.

” X becomes (1 + i)/(l + r) where L is the rate of mflation and X<l. Thisassumes that the rate of inflation applies to the maintenance costs as well as toreplacement costs.

TABLE X

Example of economic life or replacement period calculation for a fork-lift truck

(A = 2S,OOO, i- = 0.10)

1 2000 1 .oooo 2000 27000 .0909 2970302 3000 0.9091 2727 29727 .1736 1712383 4000 0.8264 3306 33033 .2487 1328324 5000 0.7513 3757 36790 .3170 1160575 6000 0.6830 4098 40888 .37’,1 1078556 7500 0.6209 4657 45545 .43!j5 1 0 4 5 8 17 9000 0.5645 5081 50626 .4e68 103998”8 11000 0.5132 5645 5 6 2 7 1 .5x35 1054759 13000 0.4665 6065 62336 ..5759 1 0 8 2 4 1

1 0 16cnO 0.4241 6786 69122 5144 112503

Annex III

THE PORT DEVELOPMENT REFERENCE LIBRARY

1. Port nuthonties wth port planning respunslbiliry will requ~rr has prepared a recommended hst of port develqxnent referencem”rc information than can be provided m ‘1 rmgle handbook ‘Ihere works, which 1s reproduced belowIS a large body “1 material available and it will often be dtfflcult folthe port authbrtty ather to know what pubhcat~ons to select or toprocure them m tune for the specific planning need that may arise.

3. Thr investment of the very large wms 01 money involved mport development should be based on the best mformatlon available

2 . 11 ,I therefore adwsable for each such authority to assemble asatisfactory reference library m advance of any specifjc planmng taskso that when the tmx comes the pn,,ect planners ca,l have quickaccess to the InformatIon. For this purpose. the UNCTAD secretariat

and thcref”;e Justifies the allocatmn of modest fundr t” purchase thehst given in its entxety It mlpht be advisable for authorltles to orderthe ent!re ltst through a large c”mmeraal hook agent rather thantrymg t” order books mdiwdually.

.4ruhor

Recommended list of works on port development

T,,,?

A. WORKS II\’ ENGLISH ONLY

Agnew, J. and Huntley. J. Container stowage: a practxal approach

Amerrcan Association of PortAuthorities

Port plannmg, design and c”nstructt”n. a manual prepared byStandrng Commmee IV, Construction and Mamtenance

American Society of Civil En-gineers

American Society of Civil En-gineers, Task Committee onPort structure Costs

Apple, J. M.

Baker, C., cd.

Report “n small craft harbors

Port structu1e costs

Plant layout and matertals handling. 2nd cd

Progress m cargo handlmg, vol. 6, Changing user reqmrements

Baud&ire, J. G.

Bird, J.

Bird, .I.

Bird. J.

Bow, A. H. J.,

Port administration and planning: general introductmn

Seaport gateways of Australia

Seaports and seaport terminals

The major seaports of the United Kmgdom

Port economics, 2nd ed., rev by W. A Flue

Boyes, J. R. C. Containerization International Yearbook

Bruun, P. M. Port engineering, 2nd ed.

Dally, H. K. “Straddle curler and container crane evaluation”. National PortsCouncil Bulletm No. 3

Economist Intelhgence Unit Investment: the growmg role of export processing z”nes

FA0 Fishery harbour planning

FAO, ed.

Fugl-Meyer, H.

Conference on fishmg ports and port markets, Bremen, 1968

The modern port, Its facthties and cargo handling problems

Glassner, M. I. Access to the sea for developing landlocked states

Hedden. W P. Mission: port development wth case studies

225

Contamer Publications Ltd.. Dover(Umted Kingdom). 1972

American Association of Port Au-thorma, Washington. (D.C.).1 9 7 3

American Society of Ctvil En-gineers. New York, 1969

Amencan Society of Civil En-gineers. New York, 1974

Ronald Press. New York, 1963

Bowker Puhbshing C o . L t d . .Epping (Essex, Umted King-dom). 1976

Delft (Netherlands)

Oxford Umversity Press, London,1 9 6 3

Hutchinson, London. 1971

Hutchinson, London, 1963

Dock and Harbour Authority.London. 1967

National M a g a z i n e C o . L t d . ,London

Gulf Publ ishing Co. , Houston(Texas), 1976

National Ports Council, London.1972

EIU Ltd., Special Report No 64,London. 1979

FAO, Rome; Fisheries TechnicalPaper No. 123

Fishing News, London, 1970

Damsh Technical Press, Copen-hagen. 1957

Martmus Nljhoff, T h e H a g u e ,1 9 7 0

Amencan Assocranon of Port Au-thorities, Washington. (D.C.),1 9 6 7

Hoyle, B. S

International Cargo HandlingCo-ordmatlon Associat ion(ICHCA)

Lederer, E. H.

Nagorski, B.

National Ports Council, UnitedKingdom



Oram, R B. and Baker, C. C.R .

Rath, E.

Tabak, H. D.

Takel, R . E

Thoman. R. S

Thomas. R. E

UNIDO

United Nations

United States Department ofTransportation

Evans, A. A

ICO

International Federation ofConsulting Engineers(FIDIC)

UNIDO

United Nations

United Nations

United Nations

United Nations

United Nations

United Nations

United Nations

The seaports of East Africa: a geographical study

Ro-ro shore and ship ramp characteristics: a survey

Port terminal operation: port terminal management

Port problems in developing countrxs: principles of port planningand organization

Bulletin No. 9: port perspectives 1976

Equipment evaluation: an examination of the use of fork-lift trucksin the ports

Port structures: an analysis of cats and design of quay walls, locksand transit sheds, ~01s. I and II

The efficient port

Container systems

Cargo containers: thar stowage, handling and movement

Industrial port development. with case studies from South Walesand elsewhere

Free ports and foreign trade zones

Stowage; the propertIes and stowage of cargoes, rev. by 0. 0.Thomas, 6th ed.

Handbook on export free zones

Gmdelines for the physical security of cargo

Technical and social changes in the world’s ports

Guidelmes on the provision of adequate reception facilities inports, 3 VOIS.

Conditions of contract (international) for works of civil engineeringconstruction with forms of tender and agreement, 2nd ed.

Manual on the use of consultants in developing countries

Physical requirements of transport systems for large freight con-tainers

Berth throughput: systematic methods for improving general cargooperations

Port performance indicators

Guidelines on the introduction of containerlzation and multimodaltransport and the modernization and improvement of the infras-tructure of developmg countries

Manual on a uniform system of port statistics and performanceindicators

Technological change in shipping and its effects on ports

East African Publishing House,Nairobi, 1967

ICHCA, London, 1978

Cornel l Marltime Press, NewYork, 1945

The International Association ofPorts and Harbors, Tokyo, 1972

National Ports Council, London,1 9 7 6

National Ports Council, London,1973

Bert l in and Partners , London,1 9 7 0

Pergamon Press, Oxford, 1971

John Wiley and Sons, New York,1973

Cornel l Mari t ime Press , Cam-bridge (Maryland), 1970

Scientechnica, Brtstol (UnitedKingdom), 1974

Cornel l Mari t ime Press , Cam-bridge (Maryland), 1956

Brown, Son and Ferguson, Glas-gow. 1968

UNIDO, Vienna; Sales No.UNID01100.31

United Nations document UNC-TAD/SHIP/138

United States Denartment ofTransportation, ‘Washington,(D C.), 1972

ILO, Geneva, 1969 (Studies andReports, New Series, 74)

ICO. London; Sales Nos. 77.02.E,78.12.E and 80.03.E

FIDIC, Paris, 1979

United Nations publication, SalesNo. E.72.II.B.10

Umted Nations publication, SalesNo. E.71.II.D.Z

Umted Nations publication, SalesNo. E.73.VIII.l

United Nations publication, SalesNo. E.74.II.D.l

United Nations publication, SalesNo. E.76.11.D.7

United Nations publication, SalesNo. E.83.11.D.14

United Nations document UNC-TADISHIPI185IRev.l

IU”i!Pd NZ!iO”S docnmP”t TDllYC.41129 and Supp. 1-6(mimeographed]

226

Idem: the xnpact 01 unitizatron on port operations

Idem. cost comparisons between break-bulk and various types ofumt-load berth

ldem Selection, collection and presentation of statisilcal informa-tmn concerning contamrr and barge operations m ports

Idem: rstabhshmg tariffs for umt load and multi-purpose terminals

Idem: the tmpact of technological developments tn bulk trafftc onport fac1httes

Idem: currenl developments in seagomg barges and barge-carrymgvessels

Appralaal 01 port investments

Gudelines for procurement under World Bank loans and IDAcredltr

Uses of consultants by the World Bank and it, borrowers

TD/BiC4!12Y/Supp 1

TDiBIC.41129lSupp.2

TD:BK 4112Y/Supp.3

TDIBiC.4/12Y!Supp.4

TDiB/C.4/12Y/Supp.S

TD!B/C.4/12Y/Supp.6

United Nations document TD/B!c.41174

United Nations

United Nattons

United Nations

United Natrons

United Nattons

United Nations

United Nations

World Bank

World Bank

Blasset, M.

Blosset, M

Chapon, J.

Larras, I.

Regul, R., ed.

Untted Nations

C . WORKS th FRENCH ONLY

Theorie et pratique des travaux B la mer

Travaux B la ma: prects de construction et d’exploitation des ports

Travaux maritlmes, vols. 1 and II

Cows d’hydraulique marttttne et de traraux maritimes

L’avenir des ports europCens, ~01s. I. and II

Manuel de gestion portuaire

World Bank, Washmgton (D.C.),1977

World Bank. Washmgton (D.C.).1974

Eyrolles. Parts, 1951

Eyrolles, Paris, 1959

Eyrolles, Paris, 197675

Dunod, Parts, 1961

De Tempel, Bruges. 1971

Untted Nations publication, SalesNo. F.gO.II.D.4

227

Prinwd m G r e a t Britaln 023OOP Uni ted Nanons puhhcalionGE.84.55476 (X66)-March lYX5--1.3’)(1 Sale\No E.84.11 D.1

ISBN 92-l-112160-4