International Journal on Public Works ... - IADC Dredging...importance to the future success of the dredging in-dustry. The full text of the presentations by the speak-ers is available

INTERNATIONAL ASSOCIATION OF DREDGING COMPANIES

International Journal on Public Works, Ports & Waterways Developments

Number 63 - June 1996

Terra et Aqua – Number 63 – June 1996

Terra et Aqua is published quarterly by the IADC, The International Association of Dredging Companies.The journal is available on request to individuals or organisations with a professional interest in thedevelopment of ports and waterways, and in particular, the associated dredging work.The name Terra et Aqua is a registered trademark.

EditorMarsha R. Cohen

Editorial Advisory CommitteeR.C.W. Brouwer, ChairmanJ. Boeter P.J.A. Hamburger E.A.M. StraussH. van Diepen H. de Vlieger P.G. RolandH. Fiers C. Paris Solas

Editorial AddressTerra et AquaDuinweg 212585 JV The Hague, The NetherlandsTel. 31 (70) 352 3334Fax 31 (70) 351 2654

Please address inquiries to the editor.Articles in Terra et Aqua do not necessarily reflect the opinion of the IADC Board or of individual members.

© 1996 IADC, The NetherlandsAll rights reserved. Electronic storage, reprinting or abstracting of the contents is allowed for non-commercial purposes with permission of the publisher.

ISSN 0376-6411

Typesetting and printing by Opmeer Boekdruk Offset bv, The Hague, The Netherlands.

Front cover:As part of the pilot project to build an island in the IJ-meer, a multifunctional pontoon was built. The pontoonfirst placed the geotextile on the seabed and then, as a spraying pontoon, covered it with sand. The pontoon is seen here waiting to lay the geotextile (see page 21).

IADCDuinweg 212585 JV The Hague, The NetherlandsTel. 31 (70) 352 3334Fax 31 (70) 351 2654

International Association of Dredging Companies

2 Editorial

3 The Role of Education and Training in Dredging

John F. Riddell

At the WODCON XIV, ten panelists from various educational institutions and the dredging industry discussed the need for improved training opportunities.

10 A Training Simulator for Cutter Suction Dredgers: Bridging the Gap betweenTheory and Practice

C.M. Cox, J.A. Eygenraam, C.C.O.N. Granneman, M. Njoo

Computer simulations are becoming a significant, controllable and safe way of gettingtheoretical knowledge out of the “labs” and onto the dredge sites.

19 The Human Factor

Walter Moret

High-tech dredging companies are thinking as much about investing in “human capital” asthey do in materials and equipment.

21 Construction of a Pilot Project Island in IJ-meer

J. Kranendonk and J. Vlak

To create new land new techniques have been developed for the placement of sand in thinlayers. They have proven both incredibly accurate and economical.

27 International Seminars on Dredging and Reclamation 1996

IADC's short dredging courses presented in Singapore and Delft continue to attractparticipants from all over the world. New ones are planned for 1997.

29 Books/Periodicals Reviewed

PIANC's newest publication on the handling and treatment of CDM, the ICE's Dredging,A Design and Practice Guide and new CUR manual are evaluated.

31 Seminars/Conferences/Events

Courses and conferences in Belgium, Texas, Poland and The Netherlands are coming up in the rest of 1996; and the first “Call for Papers” for WODCON XV in 1998.


CO N T E N T S


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EDITORIAL

Although “Dredging Benefits” was the theme of the WODCON XIV held inAmsterdam in November 1995, another subject was also placed in the limelight –education in, and about, dredging.

How does the dredging industry educate its own? How do we ensure that highquality personnel continue to be attracted to the dredging industry? What sorts ofinstitutes and universities and on-the-job training programmes exist in the field ofdredging? In the lively discussion during the closing session of the conference itbecame clear that this is a subject of great interest to many. Several articles whichappear in this Terra et Aqua are drawn from the conference papers and directlyreflect this concern. In addition to longer, high tech and engineering studies, theneed for short-term courses was given high priority. For this reason extra attentionis given to the IADC’s intensive, week-long seminar. Originally conducted at theInstitute of Hydraulic Engineering in The Netherlands, for the last two years it hasalso been presented in Singapore. Future plans include holding it in other venuesin other areas of the world, as the demand arises.

The issue of education is not only internal, however, that is, within the industry.Emerging clearly from the discussions at the WODCON was the need for moreand improved information channels to the “outside” world. More books, articlesand so forth targetted to a broader audience would definitely be advantageous tothe industry. IADC has for many years supported this approach. For that reason ithas taken an active role in the cooperating with other worldwide dredging andmaritime organisations to create and distribute new publications such as thePIANC’s Handling and Treatment of CDM from Ports and Inland Waterways (seepage 29); the soon-to-be-published series on Environmental Aspects of Dredging(developed jointly with CEDA); and the new computer programme DEBBY, acomprehensive bibliography of dredging literature. As has often been said, andmost dredging companies seem to agree, it is far better to work with an educatedclient, who understands the long-term goals of a project, but it may be the job ofthe industry to provide the education.

Marsha R. CohenEditor

Abstract

The WODCON XIV held at Amsterdam in November1995 included for the first time a full session on educa-tion and training for the dredging industry. The initiativefor this session came from the Congress OrganisingCommittee, and some ten speakers with a particularinterest in the subject were invited to contribute shortpresentations. A lively discussion took place and anumber of topics worthy of further consideration wereraised. The speaker/panelists were: A.D. Bates, Consulting Engineer, United Kingdom; Professor W.J. Vlasblom, Delft University of Technology, The Netherlands; Professor Dr A. Welte, University ofKarlsruhe, Germany; Dr. R. Randall, Texas A&MUniversity, USA; Captain A. Kuruvilla, Dredging Consul-tant, India; J. Eygenraam, Royal Boskalis Westminster,The Netherlands; M. Harms, Maritime Institute "Willem Barentz", The Netherlands; Kenneth C. Wilson,Queen's University, Ontario, Canada; and Ronald deHeer, Institute for Hydraulic Engineering, Delft, The Netherlands.

This article is based on the contributions of membersof the above panel to the Education Session of theXIVth World Dredging Congress and the subsequentdiscussion. As witnessed by the size and the participa-tion of the audience, the subject of education andtraining for the dredging profession obviously gener-ates a great deal of interest and is clearly of growingimportance to the future success of the dredging in-dustry. The full text of the presentations by the speak-ers is available in the WODCON Proceedings, DredgingBenefits, Volume 2 (pp. 973-1013), while one of thepapers from this session, that of Mr J. Eygenraam, isreproduced elsewhere in this issue of Terra et Aqua.

Introduction

Education and training have not sat easily within thedredging industry. With dredging being historicallyconsidered perhaps more an art than a science, it isonly in relatively recent years that the level of tech-nology now available in dredging has resulted in the

The Role of Education and Training in Dredging

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realisation that a more formal approach to training thanpractical experience has become desirable. As dredg-ing projects have become larger and dredging equip-ment more costly to purchase and operate, there hasalso been a realisation that the consequences of ignor-ance are now too great to be any longer acceptable toeither employer or contractor.

But dredging is not a major industry. The employmentopportunities within it are relatively insignificant, both inglobal terms and within the construction industry ingeneral. The case for including its very varied interestsas a standard element of formal university or collegecivil engineering education is not one easily made.

John F. Riddell

The Role of Educationand Training in Dredging

Dr John F. Riddell is a Professor inthe Department of Civil Engineeringat University of Strathclyde, Glasgow(Scotland) UK, where he specialises inWater Engineering. For the WOD-CON XIV, he was invited by theWODCON Committee to organiseand chair the final session of theconference which addressed the issueof how people are educated andtrained, on various levels, to enter thefield of dredging.

John Riddell chairing theEducation Session at theWODCON.

For education and training to succeed, there must firstbe a demand for knowledge and a willingness to parti-cipate in the learning process. Technology and thecompetition of the commercial world have ensured thedemand. To have a healthy, flourishing world dredgingindustry is in the interest of everyone. Potential clients,their advisers and contractors must be aware of thepossibilities which dredging can offer. Fortunately thereare clear signs that the willingness to participate in the transfer and exchange of knowledge is steadilygrowing. The role of organisations such as WorldOrganisation of Dredging Associations (WODA) andCentral Dredging Association (CEDA) continues toexpand, while initiatives by the International Associa-tion of Dredging Companies (IADC) in developing Terra et Aqua to a journal of professional standing, and in initiating various awards for students and youngauthors, are to be welcomed.

One of the difficulties of dredging education is the widerange of knowledge required. Many different catego-ries of people are employed on the design and imple-mentation of a dredging project. These include dredgedesigners and builders, contractors, operators, clients,consulting engineers, project developers, financial andlegal advisers, and those with a particular concernabout the environment. How can education and trainingmeet the very disparate needs of these differentgroups? And how is knowledge to be gained, dissemi-nated and preserved? These were among some of the questions posed tothe participants in the special WODCON XIV educationsession. To assist in providing possible answers, shortpresentations were made by distinguished speakerswith specialist knowledge of or interest in dredgingeducation and training.

OPERATOR TRAINING

The opening theme of the session was the training ofdredge operators. Two presentations were made. The first was by Mr J. Eygenraam of Royal BoskalisWestminster and was followed by that of Mr M.Harms of the Maritime Institute “Willem Barentsz”.Both speakers described highly sophisticated simulatorsfor use in the training of those involved in operatingmodern dredging equipment. The Royal BoskalisWestminster simulator is able to reproduce all aspectsof the behaviour of a cutter suction dredger. Its func-tion is both to train new operators and to improve theefficiency of the more experienced crew members. No matter how good the dredger, a good operator willalways maximise the production. The simulator allowsmany different variations in soil, weather and pumpingcharacteristics to be reproduced.

The simulator has proved very popular with those who have used it, despite some initial misgivings by afew senior operators about “going back to school”. The simulator is expensive, however, and required aconsiderable capital investment by Royal BoskalisWestminster in equipment, software, buildings andstaff.

An alternative approach to simulator provision wasdescribed by Mr Harms. Pointing out that “dredgingcompanies have for many years tended to recruitformer merchant navy officers to operate trailingsuction hopper dredgers”, Mr Harms suggested that the “on the job” training traditionally used to develop both sailing and dredging skills was no longerappropriate. “There is now a strong demand for specialofficer training courses for the operational functions on


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Figure 1. Operator at work on the cutter suction dredger simulator, with trainer supervising.

Director of the Center for Dredging Studies at TexasA&M University outlined the opportunities available inthe United States. At Texas A&M University theseincluded a BSc Degree course in Ocean and CoastalEngineering which has a significant dredging input. In addition a one-year postgraduate course is offeredevery three years, mainly for employees of the USArmy Corps of Engineers, while the annual dredgingshort course attracts many participants from all sides ofthe industry. The short course includes hydraulics,dredge material disposal, and environmental and busi-ness topics. Dr Randall also mentioned in passingundergraduate programmes at the University of Florida, as well as at Maracaibo and Zulia universities inVenezuela.

Mr Ronald de Heer of the International Institute ofHydraulic Engineering at Delft, The Netherlands thendescribed the one-year postgraduate hydraulic engi-neering course offered by IHE. The course is intendedfor graduate level students who already have somepractical experience. Dredging is one of topics covered.According to Mr de Heer the programme as improvedgreatly because “in the last few years, the dredgingcourse has been offered in co-operation with the International Association of Dredging Companies, andincludes visits to dredging projects, shipyards building,dredgers and ports. Course tutors are brought in fromthe world of dredging with special attention being givento dredging contracts”.

The contribution by Professor A. Welte of the Universi-ty of Karlsruhe, Germany emphasised that “during theearly days of dredging, the development of equipment,machinery and procedures was based exclusively onthe experience and observations of the dredger crews.It was their inventive talents and wealth of ideas whichgave an essential developmental impulse to practicaldredging operations”.In Germany in the 1950s, initial modest approaches todredging education emerged from job-orientedresearch mainly prompted by practical considerations.During the initial stages of co-operation betweenuniversities, polytechnics, specialist institutes andports, together with equipment suppliers, a trendemerged for more scientifically-orientated basicresearch. As a general rule, the results of this research

board trailing suction hopper dredgers”, he stated. Thishas resulted from changes in ship management prac-tice and from the highly competitive economic situationin which contractors now operate.Dredging companies and those who operate the dredg-ers have always appreciated the value of training andupdating courses. For this reason a number of differentparties joined forces to form the Foundation Fund forDredging Training Courses. In 1992 this organisationsupported the Maritime Institute "Willem Barentsz" atTerschelling to start HOPPERTECHNOLOGY, a newcourse to train maritime officers in the sailing anddredging techniques associated with hopper dredgers.The objectives of the course are to provide dredgerofficers with a proper understanding of shore organisa-tion and shore business management, and to givethem the skills needed to contribute to optimisation ofthe dredging cycle.

The “Willem Barentsz”The Maritime Institute “Willem Barentsz” has a full-mission ship simulator to assist in achieving theforegoing objectives. The bridge simulator allows allaspects of hopper dredger sailing and dredging to beperformed, including the pipeman position. The simula-tor has involved an investment of NGL 1 million andbecame operational in September 1995. It is intendedboth for the training of mariners new to dredging andfor in-house company courses, including crew re-fresher and follow-up courses.

During the discussion about the two simulator presen-tations it was pointed out that the very high capitalinvestment in such equipment would mean that its usemust be confined to the larger dredging companies orcompany supported organisations. It was also men-tioned that training of dredge operators was notconfined to simulators, and reference was made to thespecialist operator courses offered by IHC's TrainingInstitute for Dredging.

CIVIL ENGINEERING TRAINING

Turning to the area of dredging education for civil engi-neers and others who may be engaged in the design orplanning of a dredging project, Dr Robert E. Randall,


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Figure 2. Seated, left to right, panelist/speakers M. Harms, J.A. Eygenraam, K.C. Wilson, A.D. Bates, W.J. Vlasblom.

were only made available to the party which hadprovided the financial means for the project. Thus theeducational effect derived from the research resultswas limited to a relatively small group of people.

Professor Welte continued: “The reason for thisunsatisfactory development was frequently the factthat the companies involved, both dredger manufac-turers and dredger operators, simply did not havesuitably qualified executives with the personal andspecialist skills to stimulate and guide their stafftowards achieving the set corporate objectives”.

This realisation lead to the conclusion that education indredging, in both theory and practice, was urgentlyrequired for all involved. In addition to the in-housetraining schemes of individual companies, overlappingsolutions had to be found to allow all groups involved indredging to work together. There thus arose a need forincreasing attention to be paid to learning skills in staffmanagement, project management, performancecontrol and supervision, environmental protection andthe appreciation of laws, regulations, directives andguidelines. As importantly, the knowledge of thoseinvolved on the commissioning side of a project mustbe advanced to match that of the contractors.

Professor Welte concluded by emphasising that eachindividual party must decide whether education andtraining are implemented in an organisation, and if so,at what speed and to what extent. Education andtraining are important, and it should be realised that“investment in good staff training is small as comparedwith the risks likely to be incurred by an inadequatelevel of knowledge among staff. Accordingly, theslogan must be ‘“education in dredging necesse est’ ”.

Limited MarketProfessor Kenneth C. Wilson of Queen's University inOntario, Canada then described the specialist shortcourses with which he is involved. Noting first that “the dredging industry is a mature one, which makeslarge economic contributions to both developed anddeveloping nations”, Professor Wilson observed it wasalso one which required “only a limited number ofspecially trained engineers”. Although this small groupof engineers is vital to the success of the industry, the market for dredging education is not very large.

In Canada, some information on dredging is oftenpresented as part of courses in coastal or river engi-neering. This type of presentation can hardly producedredging professionals but does give a useful overviewof the subject to engineers in related disciplines. It can also encourage those with a specific interest indredging to take advanced training at one of the morespecialised institutions such as Texas A&M and Delftuniversities.

Short Courses“Practising engineers in the dredging field can keepabreast of the latest technology in venues other thanconferences, specifically by attending short courses.Sometimes such courses are held before or afterconferences”, remarked Professor Wilson, but in hisexperience it is preferable to have a dedicated courseof four or five days duration in which lectures can becomplemented by laboratory and project work.Mention was made of the course on hydraulic transportoffered at Augusta, Georgia in the United States andcentred at the test facilities of the GIW HydraulicLaboratory. This course has been run since 1978.

To encourage close interaction among the studentsand the teaching staff, each enrolment is limited toabout thirty-six pupils. Engineers from the dredgingindustry form a significant proportion of the total num-ber of students, drawn mainly from The Netherlands,the USA and Belgium. According to Professor Wilson,initially a marked difference in approach could be seenbetween the North American and European dredgingengineers. The latter group tended towards greatertechnological sophistication combined with a reticenceto discuss their own experiences. Over the yearschanges have occurred, however, with the NorthAmericans seeing the need for greater sophisticationand the Europeans becoming somewhat more forth-coming.

The discussion on these papers drew attention to anumber of other dredging courses available, includingthe short courses run by the University of Strathclydeand those now offered by IADC, which are offered indifferent overseas locations to allow as much localparticipation as possible.

TRAINING NEEDS OF DEVELOPING

COUNTRIES

Former Chairman of the Dredging Corporation of India(DCI) Captain Abraham Kuruvilla stated in his presen-tation that he once held the view that as “dredging is a part of a marine operations, any person with a marine background could pick up dredging skills with-out any special training”. Following five and a half yearsexperience with DCI and three years in a private dredg-ing company, he had changed this view.

He now acknowledges “that one of the critical ele-ments in successfully running a dredging operation ispersonnel trained in all the various aspects of dredging,be that dredge operation, maintenance of dredgingmachinery and electronic equipment, marine and civilsurvey, or contract and project management”.As a developing country India now has a fairly strongdredging industry, with dredgers operated by the DCI, the ports, various state organisations and the


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COMBATTING IGNORANCE

The two final contributions were from Mr AnthonyBates, a UK dredging consultant, and Professor W.J. Vlasblom of Delft University of Technology. Mr Bates broached the subject of contracts, conflictsand education. He opened by stating that “it is a com-monly held view that dredging contracts are particularlyprone to conflict, but perhaps it is the case that conflictattracts attention, whereas harmonious contracts aremore likely to pass unnoticed. Regardless of the statis-tics, two things are true -- dredging usually is expensiveand is accompanied by a substantial element of risk.Education and knowledge can do much to contain theformer and reduce the latter”.

The dredging contract is in this context an importantarea. A contractor's tender price is based on informa-tion. If the information is inadequate, or misleading,such that the contractor underestimates the difficultyand cost of completion, it is likely that a claim willresult. It is not uncommon to find deficiencies in theinformation provided to contractors due to a lack ofunderstanding by the employer, or even by the consul-tant which the employer may use. Mr Bates outlinedten basic rules which should be followed if a dredgingcontract is to be completed to the satisfaction of allparties.

He concluded by strongly refuting, insofar as dredgingis concerned, the saying that “ignorance is bliss”. Ignorance is not bliss in dredging -- it is dangerous andpotentially very expensive. “Unfortunately it is notuncommon for those arranging and supervising dredg-ing works to be so lacking in knowledge of the proces-ses that they are never aware that the work is less thansatisfactory, and not been achieved at optimum cost”.Hence an unsatisfactory situation may be perpetuatedin blissful ignorance, to the ultimate benefit of neitherclient nor contractor.

Professor Vlasblom opened his presentation by askingtwo questions: “Is dredging education necessary? Can the required knowledge be learned easily in theindustry or in the field?” Before World War II and eveninto the 1960s, knowledge of the dredging equipmentto be used on a project and the methods of dredgingand reclamation were learned only in practice. Today,the dredging processes are much better understood,while dredgers have become larger, more productiveand more expensive. “These big changes in a relatively short period of timerequire a different approach to the question of educa-tion in the field of dredging”, Professor Vlasblombelieves. “The new knowledge must be transferred tonew personnel in order to avoid disappointment,prevent re-invention of already existing matters or, inthe worst case, avoid the loss of knowledge freshlyacquired”. He agrees with Mr Bates that “ignorance is

private sector. Until the 1970s there were no formaltraining programmes run for dredging personnel, andcrews mostly received on the job training from theirpredecessors -- who themselves may not have beenvery professional.

Captain Kuruvilla gave a brief run-down of the develop-ment of dredging education in India, starting with thefirst formal Indian training programme which wasbegun by DCI with the initiation of the All India Dredg-ing Cadre in 1977. The programme was meant to traindredging officers both on the deck and engine roomside. After about eighteen months of classes ashore,trainees were attached to different dredgers of DCI,while the final few months were spent in the Universityand the Nautical Engineering College, Bombay. Thisprogramme paved the way for creating a pool of well-qualified dredging officers certified by an independentexamining authority. It was found that the trainedcadets did very well on the dredgers, but for variousreasons the training programme became restricted tomeeting the particular requirements of DCI. In generalthe courses were well received, although there wassome initial frustration on the part of the newly qualifiedcadets because of the resistance from the merchantnavy officers who were then in senior positions on thedredgers. As time has gone by most of these problemshave been resolved.

Dredging training in India has benefitted greatly fromoverseas assistance with numerous short coursesbeing run with the help of both the British and Dutchgovernments, according to Captain Kuruvilla. Discus-sions have also been held to start a National Institute ofDredging Training to supply trained personnel for theIndian dredging industry, both private and government,but as yet the proposed institute has still not takenshape. This presents particular difficulties for the emer-ging private sector which does not have the resourcesto run its own training courses. The new private sectordredgers are operated mostly by people who have hadsome exposure to dredging in foreign dredgers, but theoverall level of knowledge is not at present very high.This affects the operation and profitability of thesecompanies. If the industry as a whole is to get the bestout of the large investment in dredging equipment, it isimperative that there is some arrangement made toimpart proper training to people already in the dredgingindustry and to those who want to join.

In concluding his presentation Captain Kuruvilla drewparticular attention to the training needs of the smalleroperators, both government and private, in developingcountries. These operators do not have the financialresources to send staff for training overseas and findgreat difficulty in learning about the many aspects ofdredging. The absence of low cost books and guides,written for such small organisations, also needs to beremedied.


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a main reason for dredging projects going wrong and itshould be guarded against at all times. This applies notonly to those persons working for a dredging contractor,but also for those working for the employers and theiradvisers”.

Everybody will agree that transfer of knowledge is ofvital importance. Training is a very good and relativelycheap method to achieve this aim. The question is whois training whom and about what subjects?

But Professor Vlasblom pointed out the difficulties: “In addition to knowledge of the dredging process,transfer of practical experience is required. Althoughthe latter would seem to be a simple exercise, it is not.The recent rapid changes in the dredging industry arestill proceeding, which means that the knowledge ofteachers who do not constantly relate to the subject issoon outdated.... All these developments mean thatlectures concerned with these aspects of dredginghave to be revised regularly -- an important point whichshould be kept in mind by those responsible for organi-sing training courses”.In addition, “every branch of dredging activity shouldtake its own responsibility for training their staff”. The contractor has to appreciate that exchange ofknowledge can lead to growing knowledge, ultimatelyto the benefit of all.Finally, Professor Vlasblom suggested that if the organi-sers of courses for clients and consultants sometimeshave the feeling that their courses are not adequate ornot up to date, they should take action to reach theirgoal, rather than complain about the small transfer ofknowledge from the contractor.

THE DISCUSSION

After these brief presentations, the discussion wasopened to the audience. One participant added to thelist of courses mentioned that of The Training Institutefor Dredging (TID) which provides short training cour-ses at various levels. These are theoretical or practical

or combination and simulation is also used. Suchcourses are often designed for the crews of dredgers.Others mentioned the courses organised by CEDA aswell as those offered by Hydraulics Wallingford andOxford University. In addition, it was remarked thatCEDA aims to publish state of the art reports on dredg-ing and related issues.

Professor Emeritus de Koning (Delft University) pointedout that offering education at the engineering level isnot possible in countries without a major dredgingindustry to support it. He suggested that for projects insuch countries the establishment of Joint Venturesbetween international dredging and local companies isthe only way forward.

In this context, various contributors expressed sympa-thy with Captain Kuruvilla’s remarks about the difficul-ties of developing nations. Solutions were not so easilyfound for organising courses in developing areas howe-ver, and essentially come down to the availibility offunding. It was suggested that there could well be arole for associations such as CEDA to commission and distribute relatively simple guidance notes aimed at developing countries, and to organise trainers, inclu-ding, for example, retired but highly experienced dred-ge operators from Europe to deliver on the job trainingin countries like India. As Ms Lorraine van Dam, recent-ly retired Director of CEDA pointed out, organisationswhich utilise retired technical experts do exist, forinstance, the PUM (Netherlands Management Coope-ration Programme) and the British Executives Over-seas.

The issue of funding dredging training was raised aswell in a general context. It was noted with interestthat the Western Dredging Association offered scholar-ships for the Texas A&M course, while the IADCcourses usually had company scholarships available.Short course funding often came from governmentsources, especially in developing countries. However,there were several advocates in the audience, includingseveral current students, that felt that increased financial


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Figure 3. Speaking at the Educational Session, from left to right, Professors R. Randall, A. Welte, R. de Heer and Capt. Kuruvilla.

subjects such as contract conditions and projectmanagement may be much less so.

- There is a growing necessity to educate non-dredg-ing specialists and the public at large about dredging,because it has become a subject of more generalinterest but one which often receives damagingpublicity. Environments are always impacted bydredging but not only negatively. Few people outsidethe dredging world realise that dredging, far fromcreating environmental problems, is frequently usedto solve such problems arising from other humanactivity.

There was certainly very considerable benefit to theparticipants from the education session. Not everyquestion was answered, and not every issue wasaddressed. There is much still to be done, and theproposal that a further education session should beincluded in WODCON XV in Las Vegas in 1998 waswelcomed by all.

support for education and training should come fromthe dredging industry itself.

Educating the General PublicA concluding remark was made by Mr Peter Hamburger,Secretary General of the IADC, that “although technicaladvances are given a great deal of emphasis at dredg-ing congresses worldwide and also at the WODCON,this amounts to dredgers speaking to themselves. Verylittle attention is spent to educating the general publicabout the economic and ecological benefits of dredg-ing. This is an issue which is clearly of growing urgencyin today's world where governments must often winpublic support for their dredging projects and policies.International associations should perhaps give moreattention to how this could be done, possibly throughpublications, seminars and congresses which aredirected to a broader public than that of the dredgingfraternity”.

Conclusion

In viewing the many contributions made by both thepanelists and the audience, the wide variety of dredg-ing education emerge. Education by no means has the same meaning to allparties. To mention a few aspects:

- There are the needs of those who operated thedredgers. At one level these were being met byhighly sophisticated and expensive simulators, atanother they were not being met at all. How wasbasic training to be given to the operators employedby the many small dredging contractors, ports andgovernment agencies throughout the world, andespecially in developing countries?

- An increasing number of short courses are offeredby both educational and trade organisations. If up todate and well presented these could be of greatassistance to those employed by clients and consul-tants, as well as by smaller contractors. The problemappears to be accessibility to the courses. To savecosts and allow the maximum participation, coursesare best run in the demand countries. But costs stillexist. How are they to be met? Is there a role fororganisations such as WODA and IADC, or should itbe left to sympathetic governments?

- Dredging education should include clients, consul-tants, contractors and regulators. Within each ofthese areas is a further range of knowledge require-ments. Mariners, civil engineers, mechanical engi-neers, naval architects, surveyors, electronic engi-neers, accountants, managers, environmentalscientists may all interact on a dredging project.Some knowledge areas are very specific – pipelinetransport or pump performance, for example – while


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C.M. Cox, J.A. Eygenraam, C.C.O.N. Granneman, M. Njoo

A Training Simulator for CutterSuction Dredgers: Bridging the Gapbetween Theory and Practice

Abstract

The last decades have seen a major improvement inthe knowledge of the dredging processes. Researchand Development work from laboratory tests and fieldwork resulted in improved mathematical models de-scribing the behaviour of the cutter suction dredger. In this regard, some interesting process models havebeen developed for interaction between the soil andthe cutterhead, behaviour of the dredger in waves andcurrent, control of winches and the forces on anchorsand spuds, and suction process, pumping and hydraulictransport of the mixture. This know-how has been usedto improve the calculation rules for production esti-mates and for modifications of the dredger. Included inthe modifications of the dredgers are improved instru-mentation and automation systems. But knowledge ofthe R&D engineers in the headquarters of dredgingcompanies is not easily transferred to the dredging site.

The main objective of the cutter suction dredger simu-lator is the transfer of expertise from headquarters tothe dredging site. Instruction with the simulator empha-sises the acquisition of advanced knowledge, under-standing of new insights in the dredging processes,and application of the acquired skills in practice. Benefits are expected in an improvement of communi-cation, control of the dredging processes, and most ofall production.

During the development of the simulator project greatemphasis was given to the educational aspects. First,educational goals were derived from a detailed taskanalysis of the dredging processes. Second, an instruc-tional method was defined that provides a balancebetween simulator training and instruction on thetheory of the dredging processes. Each training sessionon the simulator is embedded in a unique framework ofbriefing and debriefing with the instructor supported byinstructional materials. The educational approach hasresulted in a simulator training programme that bridgesthe gap between theory and practice.

This paper describes the benefits of the use of compu-ter simulations in the training of dredge masters andthe educational aspects relevant to the development of


10

Marius Cox graduated from the DelftUniversity of Technology, TheNetherlands in 1981 with a MSc inCivil Engineering. He started hiscareer with the City of Rotterdam. In 1982 he joined BaggermaatschappijBoskalis bv as a research engineer.Thereafter he worked as super-intendent, and as a production andplanning engineer. Since 1994 he hasbeen an instructor on the cutter simu-lator.

Jan Eygenraam graduated from DelftUniversity of Technology, TheNetherlands in 1974 with a MSc inMechanical Engineering (DredgingTechnology). He started his career asa research engineer with ZanenVerstoep nv. Since 1988 he has beenmanager Dredging Development,Survey and Fleet Automation atBaggermaatschappij Boskalis bv.

Carol Granneman graduated fromDelft University of Technology, The Netherlands in 1984 with a MScin Civil Engineering (Coastal Engi-neering). He started his career as aproject engineer with Rijkswaterstaat. Since 1991 he has been an informationanalyst with BaggermaatschappijBoskalis bv.

Melanie Njoo graduated in education-al psychology from Leiden University,The Netherlands in 1988. In 1994 shereceived her PhD from EindhovenUniversity of Technology on learningwith computer simulations. Since 1992she has been a consultant with BSO/-Human Performance CompetenceCenter bv, a subsidiary of BSO/Originbv.

Marius Cox

Jan Eygenraam

Carol Granneman

Melanie Njoo

and tuning of the system to maximise the use of thisinstrument.

EDUCATING DREDGE MASTERS

The Traditional Way of EducationIn the early years of dredging, knowledge of the dredg-ing process was solely obtained by experience. Now-adays junior dredge masters are taught the basics ofdredging at a dredging school. This knowledge, how-ever, is purely theoretical. Later on, when the juniordredge master is working with a dredging company,this theoretical knowledge is exhanced by on-the-jobexperience (Figure 2).

From time to time the theoretical knowledge of dredgemasters is updated during additional courses on dredg-ing. This education, which is mostly held in classrooms,is sometimes organised by the company itself andsometimes by the Dutch Association of DredgingContractors in The Netherlands. In both cases, howe-ver, there is always a threshold for the dredge masterwho is not used to classrooms and books.

Another way of updating the theoretical knowledge isby transferring it from experts from various staff divi-sions who are visiting dredging projects. In most casesthese experts are not familiar with teaching. For thisreason, the effect of this knowledge transfer is notalways satisfactory. Practical experience can only beacquired by dredging in day-to-day dredging projectsunder a variety of circumstances. After joining one ofthe dredging companies, junior dredge masters willgain experience on board of a dredger itself, by workingwith dredging equipment. Although they will learn agreat deal from the more experienced dredge masters,it will actually take many years before a junior dredgemaster will earn the full title of “dredge master”.

these tools. It was first published in a slightly differentform in Dredging Benefits, Volume 2, pp. 973-984 theconference papers of WODCON XIV, held in Novem-ber 1995 in The Netherlands and is published here withpermission.

Introduction

In the spring of 1995 Royal Boskalis Westminster nvcompleted the building of a training simulator for cuttersuction dredgers. This full mission simulator, which islocated in Papendrecht at the headquarters of Boskalis,consists of four rooms:– two training rooms, containing a dredging installation

with a desk monitored by one instructor station;– an instructor’s room for briefing and debriefing; and – an instruction room, where classroom activities take

place.

During a training session the instructor monitors theactivities of the dredge masters from the instructor’sroom (Figure 1).The training rooms are equipped with sound simulationand a presentation of the outdoor world, which is pro-jected in front of the dredge master. All these factorscontribute to the idea that the dredge master is locatedon the bridge of a genuine cutter suction dredger.

An extensive educational programme has been devel-oped to run parallel with the development of the train-ing simulator. This educational programme is tightlylinked to the simulator containing both the assignmentsand the instructional materials necessary for wellbalanced training. Apart from this installation mucheffort has been put into creating a Computer BasedTraining programme, which is an interactive learningplatform for individual students.

OBJECTIVES OF BUILDING A TRAINING

SIMULATOR

One of the main strategic concerns of dredging com-panies dealing with projects which are often carried outin distant countries is how to maintain and extend thequality of its dredge masters. The quality of the dredgemasters is mainly built upon theoretical knowledge andpractical experience. Furthermore, it is expected that by making the dredgemasters more aware of the dredging processes, theproduction of cutter suction dredgers will also be in-creased. Another way of improving the dredging process is bythe use of the cutter control system. This highly sophis-ticated instrument, which is already installed on severaldredgers, has already proven its success on board. On the simulator, special attention will be given to thecutter control system in respect to familiarisation with

A Training Simulator for Cutter Suction Dredgers: Bridging the Gap between Theory and Practice

11

Figure 1. A helicopter view of simulator rooms.

The Advanced Way of EducationBeing aware of the disadvantages of the traditionaleducation programme, Boskalis started the develop-ment of a training programme in which the trainingsimulator for the cutter suction dredger is the keycomponent. This training simulator contains the latestdevelopments in R&D translated into theoretical knowl-edge of the dredging processes. Furthermore, thistraining centre has at its disposal a Computer BasedTraining facility and a completely refurbished set ofinstructional materials, both attuned to the simulatorassignments.

In developing this training simulator, the following goalswere achieved:1. the threshold relating to classrooms was removed;

and2. an environment familiar to the dredge master was

created.

In particular the second goal set high standards for therequirements of this simulator because of the existinglevel of dredge masters; experienced dredge mastersare very familiar with the behaviour of a cutter suctiondredger and expect the same behaviour from thesimulator (Figure 3).

It is felt that, only by using this way of education, will adredging company be able to cope with the tremen-dous developments that are already taking place andthose expected to take place in the near future. Boththe requirement for understanding of the dredgingprocess itself and the increasing complexity of theautomation on board make high demands upon theskills of the dredge masters.

There has been a clear division between the differentapproaches to instructing a dredge master with differ-ent levels of experience. The most experienced dredgemasters already have a high level of practical knowl-edge, so it is only necessary to add theoretical knowl-

edge in order to broaden their view of the dredgingprocess. The translation of this newly gained theoreticalknowledge into practice will take place on the simula-tor.

At the lowest level the training will concentrate on thepractice of dredging. The theoretical knowledge ac-quired at the dredging schools should be sufficient toform the basis for training on the simulator.

Training with a SimulatorIn educational settings, simulators are frequently usedfor training in the use of standard procedures. A majoradvantage is the acquisition of hands-on experience ina safe environment. Moreover, simulators can be usedto assist in the comprehension of complex processes(Njoo, 1994). The main objective of the cutter suctiondredger simulator does not involve training in usingprocedures but focusses more at the transfer of exper-tise in the dredging processes from headquarters tothe dredging site (Figure 4).

The main target group consists of dredge masters withyears of on-the-job experience. They already have acommand of procedures and skills for operating cuttersuction dredgers. To enhance their performance theyhave to be offered the opportunity to learn about thelatest developments in dredging and practice newworking methods. Therefore, instruction with thesimulator emphasises:– acquisition of advanced knowledge;– understanding of new insights in the dredging

processes; and– application of the acquired skills in practice.

THE INSTALLATION

Training SimulatorBecause the emphasis of this paper lies on the educa-tional aspects, only minor attention will be given to thedredging aspects of the simulator; a brief description ofsome background on the dredging processes involvedfollows.

Based on existing and newly gained knowledge ofR&D, mathematical models have been developedwhich describe the following subjects:1. Behaviour of soil.2. Movement of the dredger.3. Process of cutting soil.4. Process of mixing soil and water.5. Generation of spillage. 6. Pumping process, including the suction and dis-

charge processes.

In order to make the interaction between cutter andsoil as natural as possible, the seabed and soil charac-teristics have to be specified in detail. The size of the


12

Figure 2. Traditional educational setting.

EDUCATIONAL VIEW

During development of the simulator great emphasiswas given to the educational aspects. First of all, edu-cational goals were derived from a detailed task analy-sis of the dredging processes cutting, swinging, suc-tion and pumping and overall optimisation of thedredging processes. Analysis resulted in educationalgoals which served as a guideline for design of bothsoftware models and training programme.Secondly, an instructional method was defined thatprovides a balance between simulator training andinstruction in the theory of the dredging processes.Dredging theory is not offered in isolation but is alwayspresented in combination with a practical assignmenton the simulator. Each assignment focusses on a

complete seabed is 200 m x 100 m. The developmentof excavation faces forms one of the major parts of thismodel. The motion of a dredger is simulated by analysing theforces working on the pontoon, ladder and cutter ateach simulation interval. These forces originate fromthe use of spud, ladder winch, side winches, soilinteraction and environmental influences like currentsand waves.

The process of cutting soil is simulated in detail bycalculating the forces which occur in the interactionbetween the cutter teeth and the soil. Cutter teeth andcutters can be changed during a training session.

Excavated material and water form a mixture, part ofwhich disappears as spillage and is not available for thesuction process. At this point the complete system ofsuction, pumps, suction valves and discharge valvesand lines is simulated.

Instructor StationThe training session is followed by the instructor on theinstructor station. This instructor station consists of twodisplays. One monitors the essentials of the dredgingprocess and controls the simulation, while the otherdisplay provides details of the individual dredging pro-cesses: cutting, moving and pumping. All details of theearlier mentioned processes are shown on thesescreens. These data are presented partly in graphicaland partly in numerical form.

The instructor has several handles to control and moni-tor the training session at his disposal; these controlsare:– marker: to locate a special event in time.– freeze: to stop the training session

temporarily.– intervention: to change settings during simulation

in order to complicate the training session for the dredge master.

– trigger: to introduce action when a certain predefined occasion occurs.

This instructor station is also used for briefing anddebriefing. The briefing application allows the instructorto prepare the training session together with the dred-ge master. During this briefing various subjects will beshown:– bottom geometry and soil characteristics;– dredger including winches, drives, pumps and such;– subject of the training session; and– expected results of the training session.

The debriefing screens are similar to the screensshown during the training session itself. Data presen-ted on these screens are based on the logfile, whichcontains numerous variables written to this file fromeach simulation step.


13

Figure 3. Dredge cabin as realised in the simulator.

Figure 4. Dredge master working with cutter automationsystem in the simulator.

specific phenomenon of one of the dredging processesand offers the opportunity for practice in a controlledenvironment. Dredge masters have to recognise thephenomenon, predict its effect, and take action toimprove the situation. Furthermore, specific assign-ments were developed that combined phenomena ofthe dredging processes and focusses on overall optimi-sation.

In total sixty assignments were developed. Eachassignment represents a defined part of knowledgeand skills and this results in a modular structure. A major advantage of this modular structure is that itprovides flexibility in the training programme. It offersthe possibility to adjust the programme to the needs ofdifferent target groups and to individual needs (seesection on training programme).

Each training session on the simulator is embedded ina unique framework of briefing and debriefing with theinstructor (Figure 5). During briefing, theoretical back-ground on the phenomenon of the assignment isdiscussed by the instructor and dredge masters. Theseinteractions are supported by instructional materials.These instructional materials, such as workbooks andcomputer-based training programmes, are specificallydeveloped to correspond with the assignments. Furthermore, the instructor can explain the circumstan-ces of an assignment with support of data and graphicson the instructor station.

When dredge masters have acquired the requisiteknowledge during briefing they can train on the simula-tor. Each assignment involves a scenario of actions forthe dredge master. The instructor can monitor the

dredge masters’ actions with specially designed instru-ments on the instructor station. Basically, the instructordoes not intervene in the learning process of thedredge master. Interference is only allowed when theaction of the dredge master will lead to situations inwhich the intended phenomenon does not occur.Occasionally, the instructor has to play other characterssuch as an engineer.

Finally, the results of dredge masters’ actions arediscussed during a detailed debriefing. The instructorcan play back parts of the session and provide thedredge master with feedback. Also, standards fordebriefing are being developed. Graphics can be usedto explain the phenomenon to dredge masters and toillustrate his actions. Most of these graphics are avail-able on the instructor station and can also be printed asan annex in the workbooks. The instructor is primarily acoach of the learning process. Dredge masters areencouraged to discover and explain the effects of theiractions by themselves although the instructor mayguide them in the right direction and can challengethem by asking questions.The following case is an example of an assignment.

Purpose of the Example AssignmentThe purpose of this assignment is to examine the useof one or two dredging pumps in relation to the maxi-mum production achievable. The dredge master isasked to draw special attention to the maximum densi-ty and corresponding velocity possible in the dischargeline.


14

instructorstation

assignmentscomputer-basedtraining

DEBRIEFINGBRIEFING TRAININGWITH

SIMULATOR

workbooks

Figure 5. Framework with instructional materials.

The Briefing Phase:

In this phase the instructor will explain the purpose of the assignment, the details of the equipment used andthe bottom and soil characteristics in which the simulated dredging processes will take place.

Equipment:

1. Details and characteristics of the ship used in this assignment. In particular the characteristics of the pumps are dealt with.

2. The discharge lines and characteristics of these lines.

Environment:

1. The bottom geometry and soil characteristics.2. The dredge profile and the position of the cutter itself in this profile.3. The position of the dredger.

Examining the knowledge of the dredge master in this respect

The instructor will ask the expectations of the dredge master in relation to the density and the velocity ofthe mixture in case of using two dredge pumps instead of one. The answers will be reported and comparedwith the answers to the same questions afterwards.


15

EXAMPLE:

Set Up

Code : p5.1Description : switch on 2nd pump

Information Standard Set Up

Ship Standard ship (underwaterpump at 5m depth)Booster noneDischarge pipeline Statical height : 0 m

Length pipeline : 2500 mDiameter pipeline : 800 mmNumber of ball joints : nonePosition booster : not relevant

Sea bed SA-4Profile Prof-p3

Coördinates lb – 55 / – 5.00Initial working method Depth cutting layer / Step / Retrack or Change Spud

layer 1 15 m / 0.5 / Rlayer 2 nonelayer 3 nonelayer 4 nonelayer 5 none

Capacity Cutting Gathering Suctioning Pumping

soil 1 – – – 3500 m3/hsoil 2 – – – –soil 3 – – – –

Tide and current none

Start Standard Set Up

Start situation Starting up cutterStarting time –Automation CDS

The Running Phase:

The dredge master sits behind the desk and the exercise starts. At first the instructor only uses one dredge-pump and asks the dredge master to get the maximum out of this configuration. In the course of the processthe mixture velocity will decrease to a level below the critical velocity under the chosen circumstances. As aresult sedimentation in the pipeline will occur.

The proper reaction of the dredge master is to ask the instructor, now in his role as engineer, to start thesecond dredgepump.

During the simulation the instructor will ask the dredge master to explain his actions and when necessary hewill give some hints in order to direct the simulation, thus avoiding the simulation moving in a completely wrongdirection.

All actions of both the dredge master and the simulator are collected in a logfile for use in the debriefing phase.

TRAINING PROGRAMME

The training programme distinguishes three education-al levels for the simulator:1. Level A:

- getting acquainted with the use of a cutter suction dredger and the simulator.learning about the theoretical background of the dredging processes (cutting, movement and pumping).

- being able to improve the performance of isolated dredging processes (cutting, movement and pumping).

2. Level B: as level A plus:- recognising and being able to explain all events

which occurred during a simulation session, limited to one of the isolated dredging processes.

- being able to optimise the dredging processes (cutting, movement and pumping).

- being able to improve the performance of the entire dredging process.

3. Level C: as level B plus:- recognising and being able to explain all events

which occurred during a simulation session- being able to fully optimise the entire dredging

process.

Amongst dredge masters, three different experiencegroups are identified:1. First/chief dredge master2. Second dredge master 3. Third/junior dredge master

The first group (first/chief dredge masters) is expectedto follow courses only for one and a half week. In thisperiod they will only deal with simulation lessons fromlevel C. This group has the highest priority with Boska-


16

EXAMPLE:

Training session


Action Trainee

Switch on 2nd pump hints: watch the following gauges:– velocity– density– vacuum– intermediate pressure 1– intermediate pressure 2– discharge pressure– production

Task instructor Following Actions– – –

The Debriefing Phase:

The main topics which are examined in the debriefing phase are:• Did the dredge master understand the relations between mixture density, mixture velocity and outgoing

pressure and the use of an extra dredgepump?• Did the dredge master take the necessary steps to achieve a higher production?

The instructor will make use of the logfile to explain the phenomena which occurred during the simulation. The logfile is made visible by means of a set of screens comparable with the screens used during the runphase by the instructor. Each of these graphs can be printed.

The dredge master will be confronted with his expectations during briefing concerning the correct relationbetween the density and velocity of the mixture in respect to the use of one or two dredgepumps.

EXAMPLE:

Evaluation


Points of attention yes no

Expected result = observed result?

Optimal

Working method optimal Depth cutting layer / Step / Retrack or Change Spudlayer 1 –layer 2 –layer 3 –layer 4 –layer 5 –

Capacity expectations Cutting Gathering Suctioning Pumping{m3/hr} {m3/hr} {m3/hr} {m3/hr}

soil 1 – – – 3500soil 2 – – – –soil 3 – – – –

Realised

Working method realised Depth cutting layer / step / Retrack or Change Spud

layer 1layer 2layer 3layer 4layer 5

Capacity expectations Cutting Gathering Suctioning Pumping{m3/hr} {m3/hr} {m3/hr} {m3/hr}

soil 1soil 2soil 3


17

lis and it is expected that the complete group will havevisited the simulator within one year.

The second group (second dredge masters) already hassome theoretical and practical knowledge of the dredg-ing process so the programme comprises only thelevels B and C. In this case the duration of the pro-gramme will be two weeks. The training of this groupis scheduled to take two years.

The most extensive training programme has been setup for group 3 (third/junior dredge master). They willbroaden and deepen their theoretical knowledge of thedredging process and gain practical experience on asimulated cutter suction dredger. Third/junior dredgemasters will follow all levels from A to C. Each of theselevels will take four days at the simulator. These cour-ses are scheduled over a period of approximately twoyears.

Conclusions

Benefits of the cutter suction dredger simulator areexpected to be improvements in communication,control of the dredging processes, and most of all inproduction.

It is possible to acquire information on the results of thesimulator evaluation at four levels (Thijssen, 1994):– learning processes, – learning outcome, – performance at the workplace, and – trading results.

At the time of the preparation of the present paperresults were not yet available but they will receiveattention in the near future. First, learning processesand outcome will be evaluated. Results of this evalu-ation will be mainly used for improving the simulatortraining programme.

Learning processesSeveral methods can be used to evaluate the learningprocess of dredge masters during training. Commonly,subjective measurements such as questionnaires inwhich dredge masters are asked to comment on theirexperiences with the training programme, instructionalmaterials and instructor are used. The major advantageof this type of evaluation is that dredge masters aregiven the opportunity to express their opinions.For the current training an additional method is used.The instructor is given the specific task of monitoringthe learning process of an individual dredge master.During briefing, the instructor asks the dredge masterto analyse the situation and to predict the results of theintended actions. Subsequently, during debriefing afterthe simulator session the instructor asks the dredgemaster to reflect on the analysis, predictions and

actions. Consequently, the instructor does not onlyevaluate the learning outcome but can also assess thelearning process of an individual dredge master. Thisinformation is important when adjusting the trainingprogramme to the individual needs of a dredge master.

Learning outcomeAt this level the knowledge and skills of the dredgemasters acquired during the simulator training areevaluated. The most common example of this type ofevaluation is an examination. For the current trainingprogramme, which aims at understanding and enhan-cement of performance at the working place, an exami-nation of a practical nature is essential. An option is asimulator test session in which dredge masters areasked to perform in a complex situation. Essentialperformance indicators should be selected to measurelearning outcome in a simulator session and the work-place itself.

To make an accurate evaluation of the contribution ofthe simulator training a pre-test/post-test design isnecessary. A dredge master’s level of competence isthen tested before and after a part of the training.Timing of the post-test is important. Testing after aperiod of time has elapsed will probably give a morereliable measurement than directly after the training.

At an individual level, results of an examination mayaffect continued participation in the training program-me, e.g., if a dredge master fails the test he has to dosome retraining before progressing further in thetraining programme.

At a later stage, when the simulator training has beenimproved and performance indicators have been valida-ted, performance at the workplace and trading resultscan be evaluated.

References

Njoo, M.K.H. “Exploratory learning with a computer simulation: learning

processes and instructional support”. 1994.

Thesis, Eindhoven University of Technology, The Netherlands.

Thijssen, J.G.L. “Effectevaluatie binnen bedrijfsopleidingen” (Effect evaluation

within company training). In: Gids voor de opleidingspraktijk

(Guide to Training Practices). 1988.

Bohn Stafleu Van Loghum, Houten, The Netherlands.


18

The Human Factor

19

Walter Moret

The Human FactorAbstract

An important side effect of the technological renova-tions in the dredging industry is the upgrading of thetraining requirements for operational staff. Nearly allrecently hired employees in dredging companiesappear to be educated at secondary or higher leveltechnical schools. The phenomenon of apprenticedredgers is no longer common in the more developedcountries. The human factor has thus become animportant aspect in developing successful policy, andeffective management of human resources is as mucha part of the modern, high-tech dredging industry as isthinking in terms of costs and expenditures.

Introduction

An important side effect of the technological renova-tions in the dredging industry is the upgrading of thetraining requirements for operational staff. It is interes-ting to note that a recent study published by the Dutchlabour union FNV, when referring to the constructionsection, reported that nearly all recently hired employ-ees in dredging companies appear to be educated atsecondary or higher level technical schools. In fact, thephenomenon of apprentice dredgers being trained onthe job is no longer common practice in the moredeveloped countries. In these countries dredging hasbecome a venerable technological activity.Each venture’s strategy is developed and put intopractise by people. The human factor is thereforeessential in determining a successful strategic policy.Thus a successful managment of organisations, inde-pendent of the juridical structure, actually implies theeffective and objective handling of human capital.Effective management of the human workforce in atechnolgically highly developed industry, such as themodern internationally operating dredging companies,has evolved from thinking in terms of costs and expen-ditures to thinking in terms of investments and addedvalue.

MOTIVATED PEOPLE

Within an organisation a motivated person is moreimportant than a nicely formulated management policyor other developed internal structures. In this context,human capital is one of the recognised elements in theorganisation. Investments in people are unlike otherinvestment components, such as equipment and other

production factors, because they are not expresssed inmoney terms in the company’s official annual report. However, the considerable importance of these invest-ments are shown in an indirect way: For example bythe action pictures in official company publications.The first page of the 1993 Annual Report of the HBGGroup shows a full page action picture of a femalesurveyor from dredging company HAM. Also the An-nual Report of Royal Boskalis Westminster containsseveral colourful action pictures of employees. The human factor has however been given even moreattention in the company brochures. These brochuresnot only present a concise outline of the strategic aims,organisational structure, main types of dredging equip-ment, and recently realised projects. By means ofaction photos an impression is given of the humanversus machine relationship, suggesting an obviouspresence of know-how and experience.To date only Royal Boskalis Westminster publishes anSocial Annual Report. Amongst other issues covered inthis document, they describe their social and personnelpolicy, including training and educational activities ofthe recently graduated engineers they have employed.

INVESTING IN PEOPLE

The significance of investing in young people is a mat-ter of great importance to most of the large internation-ally operating dredging companies. In the Boskalis 1992Social Annual Report it is emphasised that “healthygrowth” means that ”more attention is given to qualityand safety”. The CEO of the Belgian Dredging Interna-tional/Overseas Decloedt (DEME) described the year1992 as ”the year of training and perfecting the techni-cal staff”, in preparation for the future in which invest-ments include not only new dredging equipment butalso focus on people and quality. And the Japanese

In the 1960s Walter Moret began hiscareer as a public accountant inFrench-speaking European countries.He then joined the industry consultingdivision of Ernst & Young in the1970s and focussed his expertise onthe contracting industry. He is pres-ently a Partner at Ernst & Youngindustry consultants.

Walter Moret

dredging company Penta Ocean also puts an enormouseffort into recruiting young employees with potential.

Finding the BestEvery year the personnel departments of these largedredging companies are inundated with hundreds ofapplications from recently graduated engineers. Buteven earlier on, many of the companies give students,prior to graduation, the opportunity to gain practicalexperience by offering internships and guiding their finaltheses. In fact these days the large dredging companiesno longer have to rely on personnel advertisements tobe sure of attracting their quota of well-qualified youngtechnicians. Internships, information days at universitiesand other technical educational institutions, plus, lastbut not least, personal contacts, ensure the dredgingcompanies a large pool of well-qualified people.

TrainingOn an annual basis dozens of young people participatein the trainee programmes organised by Boskalis andDEME. After a selection process, these trainees areoffered a contract by the company and are given aperiod of time to familiarise themselves with the com-pany’s entire operation, including work experience athome and abroad. At Boskalis all trainees are guided by a mentor fromsenior management for a period of twelve months. The purpose of this mentorship is twofold. On the onehand the trainees are given the opportunity to discusstheir experiences, problems or questions with thesenior managers; on the other hand these managers,who have operational responsibility, can acquaint them-selves with the working methods and policies withinthe organisation on a regular basis. What is more, thisstructure stimulates a collective team spirit. Besides gaining work experience, trainees are guidedby a central coordinator from corporate headquarters.This staff person also has a key position in organisingsupplementary theoretical education which is givenwithin the company. Penta Ocean seems to maintain a simliar strategyhiring between 100 and 200 young technicians each

year. Since a large part of Penta’s activities are in civilengineering, a central in-house training is conducted inthis area in which work experience is gained on specificconstruction projects. When Penta’s dredging depart-ment, one of the largest private dredging organisationsin the Far East, needs new experienced people, theycan appeal to the engineering corps of the group.In the industrial branch in The Netherlands a variety oftraining programmes have been developed so thatDutch dredging companies can rely on external trainingfacilities. But individual companies continue to developtheir own in-house programmes. For instance, Boskalishas recently developed a cutterhead simulator to trainits employees. And DEME has been using a hoppersuction dredger simulator for quite some time. DEMEhas concluded that for the optimal use of dredgingequipment, the transfer of personal know-how andfamiliarity with the most relevant types of dredgingequipment is essential. Although the financial cost ofdeveloping human resources is significant (approx. US$ 50,000 or more per trainee), both Boskalis andDEME bear this patiently as a long term investment.

Team SpiritAs at Boskalis with its system of mentors, the develop-ment of a collective team spirit is of great importanceat DEME. DEME striving for the same goal publishes abi-monthly newsletter The Beaver for internal commu-nication and information on company policy. In addition,DEME organises in-house seminars a few times eachyear to reach this objective. Within the framework ofthese seminars discussions take place about specificprojects which are of core importance to the group.Engineers who share comparable functional responsi-bilities participate in this “exchange of ideas” program-me. In addition, the seminars focus on social aspectswhich will strengthen contacts within the group. At Penta Ocean as well a permanent structure of in-house education has been developed for engineerswith 5 to 10 years work experience. Depending on thelevel of education and the pace the individual sets forbecoming familiar with company policies and assumingresponsibilities, an engineer can progress from assist-ant supervisor to supervisor to executive supervisor inapproximately 10 years time.

Conclusion

Well-trained and well-motivated employees form thecore of a long-term investment. Management must inthis respect ask itself how best to use the organisa-tion’s human capital. This should include a vision andaction plan of how it can avail itself of equally qualifiedand motivated people in the future. The challenge ofmanagement when recruiting and training new employ-ees is to stimulate them to give the utmost of them-selves and to encourage them to feel an interest in theorganisation.


20

Team spirit on the job during a beach nourishment projectalong the south coast of England. Well-trained motivatedpeople can make the difference in the success of a project.

John Kranendonk and Jan Vlak

Construction of a PilotProject Island in IJ-meer

intervals (mixture-flowrate and mixture-concentration,offset from line, and so on).From a dredging point of view, this project demonstra-ted that developments in production automation inrecent years enable an economical performance withaccuracies never before attained.

This paper was first published in the conference pro-ceedings of the WODCON XIV, Dredging Benefits,Volume 1, pp. 393-404 and is reprinted here with somerevisions with permission.

Introduction

As part of the development of IJ-burg (a planned resi-dential housing area next to Amsterdam), a pilot projectin the IJ-meer had to be executed. The works involvedof the construction of a small island in the shallow

Abstract

Since 1990 HAM-VOW has been working to developthe technical and economic possibilities of constructingbuilding sites for housing on the very soft seabed in theIJ-meer, close to the city centre of Amsterdam. In November 1991 the Municipality of Amsterdam and HAM-VOW started preparations for the construc-tion of a pilot island.One of the possible, economically feasible methodsselected was to cover the soft seabed material withgeotextile on which sand would be placed in thin layerswith very narrow tolerances. However, this way ofplacing sand in thin layers required the development ofnew techniques. To test these new techniques it wasdecided to construct a small island as a pilot project.

In this paper details of the manufacture and placing ofthe geotextile are discussed. A special pontoon wasbuilt for the placing of the textile. This pontoon wasequipped with computer controlled winches whichenabled the pontoon to move along a defined line witha maximum tolerance of 0.5 metres (accuracy of posi-tioning system included). In this way the requiredoverlap between the separate textiles could be guaran-teed in an economical way.

As soon as the geotextile was in place, the pontoonhad to be converted into a spraying pontoon. The sand-water mixture was pumped from 1,500 m3 barges by abarge unloading dredger (Sliedrecht 26; total output ofengines 4,780 kW), through a partly submerged andpartly self-floating pipeline with a total length of approxi-mately 1,300 metres, to the spraying pontoon. To beable to spray in thin layers with a high production-output, the pontoon was equipped with several controldevices. The computer controlled winches of thepontoon were used to move it along defined lines at aspeed related to the concentration and mixture-velocityof the sand-water mixture. In this way three layerswere sprayed up to the existing water level with thick-nesses of successively 0.7, 0.5 and 0.7 metres.

To be certain all demands were met and to be able toevaluate the whole process, the relevant processparameters were logged on the computer at regular

Construction of a Pilot Project Island in IJ-meer

21

In 1990 after graduating with a BSc inCivil Engineering, Mr John Kranen-donk went to work for Ham dredgingand marine contractors. He has wor-ked on many projects including inHong Kong. He is involved in theproduction calculations during thetender stage of projects, and visitsworks-in-progress for productionanalyses.

Jan Vlak was employed at VolkerStevin Dredging bv for ten years on awide variety of projects in TheNetherlands and in Nigeria. In 1991he joined the Ham where he is pre-sently involved with the preparation,planning and implementation of thedepot for dredged materials in theKetelmeer.

John Kranendonk

Jan Vlak

Figure 1. Side and top view of the multifunctional pontoon.

areas of the IJ-meer, east of Amsterdam. The pilotproject served two main purposes:1. to check whether the subsoil behaved as

calculated; and2. to test the proposed equipment to be used for the

construction of the new housing area.

Because the subsoil in the area consisted of very softmaterial, especially the top layer, and disturbance of thesubsoil had to be avoided, it was necessary that ageotextile should first be placed on the bottom of theIJ-meer. This geotextile was then covered with thinlayers (0.50-0.70 m) of sand. To avoid excessive expen-diture for this project, a pontoon was designed and builtwhich was able to place the geotextile and which, after

minor conversions, could also serve as a sprayingpontoon to place the sand.

DESIGN OF EQUIPMENT

Design ConditionsDesign conditions had to be determined for, first of all,the laying of the geotextile and secondly, the placing ofsand.

Laying of GeotextileThe following requirements were applicable to thelaying of the textile:– The geotextile should be placed in lanes with a

minimum width of 25 metres.– The overlap between two lanes should be 2.50

metres.– The maximum horizontal tolerance should be within

0.50 metres of the defined line.– The placed geotextile had to be ballasted with sand

as soon as possible.

Placing of SandThe following requirements were applicable to theplacing of sand:– The sand had to be placed in layers with a thickness

of 50 to 70 cm.– The tolerance in placing of the sand layers was

-15/+10 cm.– The last layer had to be placed at a water depth of

approximately 70 cm.

Design of Multifunctional PontoonSince one of the purposes of building this test island inthe IJ-meer was to test the equipment for both placinggeotextile and sand, it was necessary that the equip-ment was designed to handle large quantities. Thismeant the laying of 25 metres wide geotextile at aminimum laying speed of 2 m/min and attaining asestimated sand production of approximately1,000 m3/hour. The tolerances mentioned above madeit necessary that the pontoon was moved by constanttensioning winches. Furthermore it was anticipatedthat these tolerances could not be met by operatingthese winches manually. Therefore the shifting of thepontoon had to be controlled by a computer.

To handle the 25 metre wide geotextile it was neces-sary that the pontoon had a length of 34 metres. Forstability reasons and in order to reduce the draft to lessthan 50 cm, the width of the pontoon was 17 metres.To place the sand a chute was designed which had tobe capable of spreading the sand over a width of 12metres. The velocity in the chute had to be maintainedsuch that sedimentation did not take place on thechute. A side and top view of the pontoon is shown inFigure 1. The pontoon waiting to lay the geotextile canbe seen in Figure 2.


22

Figure 2. The polyester mats are rolled around a speciallymade pipe. Top and right are parts of the six-point anchoringsystem.

the accepted tolerances. The data from the positioningsystems (Axyle radio positioning system and geodime-ter) were fed into this computer which manoeuvred thepontoon along the predetermined line at the predeter-mined speed. The dredge master could follow thelaying operation at the computer displays and, if necess-ary, overrule the computer in case of emergencies. The pontoon was gradually moved along its line (speedapproximately 3 m/min) and the geotextile was placedon the seabed. A minimum force was kept on the rollby a brake to keep control at the unrolling. At the end ofthe line the geotextile was loosened from the roll andthe pontoon was moved back to the starting point topick up the anchor beam from the seabed. From thispoint on the operation could start again. The layout ofthe island with the mats of geotextile is shown inFigure 5.

Ballasting of GeotextilesThe polyester of which the geotextile was fabricatedhad a specific gravity of 1,380 kg/m3 and, taking intoconsideration that some air bubbles were trapped intothe textile, this might tend to float. Therefore it wasdecided to ballast the geotextile. For ballasting purpos-es a pontoon with a hydraulic grab crane on board, wascoupled to the laying pontoon. About 150 m3 of sandwas stockpiled either side of the crane. When the

CONSTRUCTION OF UNDERWATER PART OF

TEST ISLAND

The GeotextilesThe three different types of geotextiles were manufac-tured according to special requirements, and were thenprepared to be transported by road to the work site. At the work site they were placed on the seabed by alaying pontoon.

Fabrication of TextilesIn the factory of Nicolon at Almelo, threads made ofpolyester were woven into mats approximately 5.10metres wide and of the required length (60 or 160metres). These mats were sewn to produce 25 metrewide strips. These new mats were rolled around aspecially made pipe (diameter 800 mm and lengthbetween flanges 26.50 metres). The finished rolls werecovered with a sheet to protect the geotextile duringtransport.

In this way three different types of geotextiles werefabricated:– Stabilenka 200/45– Stabilenka 400/50– Geolon 15

Transport of Textiles from Factory to Work SiteThe rolls were transported from Almelo to Amsterdamby road. One special transport truck could load one roll.Two rolls at a time were delivered at Amsterdam,unloaded from the trucks, and placed in the jibs of thetransport pontoon. The transport pontoon was towedfrom the quay wall to the work site and the rolls werepicked up from the transport pontoon by two hydrau-lically manipulated jibs on the laying pontoon.

Placing of TextilesThe laying pontoon was moored on a six points anchor-ing system. To meet the required accuracy, goodanchoring was very important. Because of the pooranchoring soil conditions it was decided to place anchorpiles around the proposed island. However, a fewplaces could not be used to place anchor piles so inthese areas two 6.5 tons Stevpris anchors were used.The geotextile was fixed to an anchor beam (seeFigure 3) by means of ropes and the anchor beam waslowered to the right position on the seabed.At both ends of the anchor beam two stakes with flagswere placed to check the position of the anchor beamat the start of the operations. Once the anchor beamwas in the correct position the pontoon moved forwardto place the geotextile (see Figure 4).

The pontoon was shifted by means of its six winches.To stop the steelwires sinking to the bottom and caus-ing damage to the already placed geotextile, smallfloaters were placed underneath the wires. All wincheswere controlled by the computer in order to stay within


23

ANCHOR BEAM

Ballasting PontoonLaying Pontoon

W L

Figure 3. Lowering of the anchor beam to the seabed.

Progress direction

Laying Pontoon Ballasting Pontoon

W L

Figure 4. Placing of the geotextile.

pontoon moved over the geotextile the crane placedthe sand on it to ensure that it remained on the bottom(Figure 6).

Placing Sand in Thin Layers Using a SprayingPontoonAfter delivery of the sand to the work site from aborrow area, the sand was placed in three layers by aspraying pontoon.

Delivery of Sand to Work SiteThe borrow area was situated in the IJ-meer, betweenthe islands Pampus and Muiderberg. Two self-pro-pelled barges were used to transport the sand from theborrow area to the site.The barge unloading dredger Sliedrecht 26 (total outputof engines 4780 kW) was situated north of the break-water along the navigational channel and dischargedthe sand-water mixture from the barges through a1,300 metres partly submerged and partly self-floatingpipeline (diameter 700 mm), to the spraying pontoon.

Placing Sand in Thin LayersThe spraying pontoon moved by means of 6 computercontrolled winches along predefined lines, at a speedrelated to the concentration and the mixture-velocity ofthe sand-water mixture (Figure 7). The four side win-ches kept the pontoon within the allowed horizontaloffset and the bow and stern winches were used tomove the pontoon along the defined line.Driven steelpiles were used to anchor the pontoon.The side winches were controlled by the ProductionAutomation computer (PA). This PA-computer wasconnected to a survey computer. The survey computerpassed on information to the PA-computer regardingthe actual location of the pontoon and the location ofthe steelpiles, to which the anchor wires were attach-ed. With the aid of this information the PA-computercould calculate the angle of the anchor wires and theamount of tension needed by every winch, to movethe pontoon within the specified tolerances along the

defined line. The pontoon progressed in a directionparallel to the short side of the pilot island. The bowand stern winches were also controlled by the PA-computer.

The information used by the computer to determinethe progress of the pontoon along the line was:– the spraying width for each pass.– the desired layer thickness to be sprayed.– the measured sand water mixture velocity.– the measured mixture concentration.

The computer also took the relevant soil parameters ofthe sand into account. To be certain all demands weremet and to be able to evaluate the entire process, therelevant process parameters were logged on the com-puter at regular intervals. A computer programme waswritten to plot the relevant parameters into graphs(Figures 8 and 9).The mixture velocity and the mixture concentrationwere measured onboard the spraying pontoon. For thispurpose a flow meter and a density meter were moun-ted in the spraying pipe of the pontoon. To achieve acontinuous uniform spraying process it was importantto maintain a constant production rate for theSliedrecht 26.The following actions were taken to achieve a constantproduction rate:– Installation of a “flowcontrol” to keep the mixture

velocity at a fixed level.– The mixture concentration was controlled by the

dredge master of the Sliedrecht 26. During thespraying of the first two layers the dredge mastertried to keep the mixture density at 1.25 t/m3.

For positioning and line definition purpose the longitu-dinal side of the island was divided into survey lineswith a spacing of half a metre. The spraying widthdetermined for each pass was 12 metres, hence thedistance between the separate spraying lines was12 metres (24 survey lines).


24

Figure 5. Left, layout of the island with the mats of geotextile.

Figure 6. Ballasting of geotextiles.

Figure 8. Relation between progress pontoon andconcentration of the sand-water mixture.

Figure 9. Information from flow and density meters.

During the spraying operation the pontoon movedalong those lines defined in the survey computer.When the sand-water mixture left the spraying mouth adensity current was formed underwater in which, at acertain point, the sand settled down under the influ-ence of gravity. From survey records and calculationsthis sedimentation-length proved to be approximately20 metres. This was taken into account by shifting thestarting and finishing point of the line to be sprayedover 20 metres. To keep the sand within the specifiedworking area of the pilot island certain procedures wereprepared before commencement of the works. The main factor, when moving to another surveyline,was to reduce the density (which was controlled by thedredge master of the Sliedrecht 26) to approximately1.1 t/m3, which resulted in relatively low desired pro-gress velocity of the spraying pontoon.

When preparing the works, a water level of 0.40 m -NAP in winter time was assumed and an averageseabed level of 1.95 m -NAP, resulting in three theoreti-cal spraying layers of 0.5, 0.5 and 0.70 metres succes-sively. Within these figures the anticipated settlementswere taken into account. During the insurvey the actualseabed level varied between 2.10 m -NAP and 1.70 m -NAP. Based on this in-survey the actual layer thicknes-ses to be sprayed were fixed at: – Layer 1 : 0.7 metres over 2/3 of the surface of the

pilot island and 0.5 metres over the remaining 1/3 of the island.

– Layer 2 : 0.5 metres over 2/3 of the surface of the pilot island.

– Layer 3 : To fill the total surface of the island up to the existing water level.


25

Figure 7. The spraying pontoon was controlled by means of 6 computer controlled winches.

Figure 10. Accuracy of moving along a predefined line.

When spraying the third layer the working methoddeviated from the working method used to spray layer1 and 2. This will be described below. In the timeschedule the anticipated time required to execute theplacing of one layer was one week. A consolidationtime of three weeks was anticipated before com-mencing the spraying of the next layer.The placing of the sand led to increased water pres-sures in the underlaying stratum. To measure theactual water pressure three piezometers were installedin the mud layer at a depth of 3 to 3.5 m -NAP. If thereadings of the piezometers decreased to an accepta-ble level, the spraying of the next layer could com-mence. During the actual work the consolidation timewas indeed three weeks.

First Layer The first layer comprised the entire surface of the pilotisland (335 m * 160 m). The actual execution time forthis layer was seven days. In the first layer a totalamount of 33,500 m3 of sand was sprayed, divided

over 27 spraying lines. The average output of theSliedrecht 26 was 920 m3/hour (with a maximum bulkproduction of 2,200 m3/hour).

Second Layer The second layer comprised 2/3 of the surface of thepilot island. Due to the shape of the slopes of the islandthe length of the spraying lines was decreased from160 to 115 metres. The actual execution time for thislayer was three days. In this layer a total amount of11,000 m3 of sand was sprayed, divided over 17spraying lines. The average output of the Sliedrecht 26was 800 m3/hour. Due to a storm during the executionof this layer the waterlevel was lowered to 0.70 m -NAP, resulting in the pontoon hitting the seabed atseveral places.

Third LayerOriginally, it was intented that the third layer would beplaced by using the automated system. However, itwas decided that the last layer would be placed byadopting a different method. Since this last layer had tobe placed up to the water level it was possible to checkthe progress visually. It was also possible to achieve agreater width of the placed sand by swinging the pon-toon somewhat. In this way a width of 30 metres couldbe achieved. Another advantage was that the produc-tion could be increased. Mixture density was nowhigher than 1.3 t/m3. Only when the pontoon wasshifted to another line the mixture density had to bedecreased. The average production during constructionof this layer was 1,150 m3/hour. During placing of sandthe pontoon was travelled backwards only. The lastlayer covered the total island with a length of the linesof 90 metres. In 8 days 41,500 m3 of sand was placed.Some delay was encountered due to strong south-westerly winds, resulting in a water level which wastoo low to operate the spraying pontoon.

Conclusions

Generally speaking, this project has shown that it ispossible to move a pontoon on anchors along a pre-determined line within very narrow tolerances.

Placing GeotextilesThe required tolerances for placing a geotextile along apredetermined line have been met. A representation ofan actual line ”sailed” is shown in Figure 10. The los-ses in width for the geotextile have been greater thanexpected (Table I).

Placing Sand Using a Spraying PontoonFor the greater part of the project (70% up to 90% ofthe sprayed surface) the required tolerances in thethicknesses of the layers of the sand were met. The actual maximum tolerances achieved are shown inTable II.


26

Table I. Width and length in factory and as placed.

Stabilenka Stabilenka Geolon200/45 400/50 15

Width in factory 25.0 25.0 25.0Width as placed 22.6 23.8 23.0Length in factory 60.0/160.0 160.0 60.0Length as placed 64.6/163.3 162.8 62.3

Table II. Actual Maximum Tolerances.

Layer 1 Layer 2 Layer 3

Required thickness 0.50/ 0.70 0.50 0.50/ 1.00Required maximum tolerance -0.15/+0.10 -0.15/+0.10 -0.15/+0.10Achieved maximum tolerance -0.20/+0.20 -0.20/+0.20 -0.15/+0.10

Charles W. Hummer, Jr.

Books/PeriodicalsReviewed

Plans for CDM Projects; 5, State-of-the-Art Technolo-gies for CDM; 6, Summary and Recommendations.

In addition, there are four Annexes: I, Sediment Classifi-cation and Primary Characteristics Affecting Contami-nant in Dredged Material; II, Method for Determinationof Sampling, Numbers and Procedures; III, Glossary ofTerms; IV, Vocabulary in Six Languages.

By way of introduction Chapters 1 and 2 take thereader through a definitions and descriptions of dredg-ed material. Chapter 1 defines the nature of sediments,the magnitude of the problem of contaminated dredg-ed materials and discusses management of dredgedmaterials. It also presents a table showing the generaltypes and sources of CDM for maintenance, capital andremediation dredging projects. Chapter 2 describes theorigin and types of dredged material, the physical andchemical characteristics of CDM and then presentsbrief descriptions of the types of contaminants. Further,the behaviour and fate of CDM is discussed as is thegeneral sources for contaminants.At Chapter 3 the heart of the report really begins. Theconcept of the Contaminated Dredged Material Techni-cal Framework (CDMTF) is described in detail. TheCDMTF is intended to be an “international road map”for nations to follow when developing and evaluatingthe appropriate options for dredging and managementof CDM. This concept and its presentation mark a majorcontribution to the technical literature on dredging.Chapter 4 goes through the various critical steps inplanning CDM projects, including project safety, ap-provals and communications plans; monitoring andoperation plans. Two valuable figures are shown, achekclist of possible planning documents and a flowchart for planning and linkages. Chapter 5 addressesthe contemporary technologies employed in this spe-cialised field, starting with surveys, and then proceed-ing to dredging processes, transport options, place-ment alternatives and types of treatment available. Finally, Chapter 6 summarises the report and offerssome recommendations. Two figures display the

Handling and Treatment of Contaminated DredgedMaterial from Ports and Inland Waterways “CDM”,Volume I. PTC, Report of Working Group No. 17. Supplement to Bulletin 89, Permanent InternationalAssociation of Navigation Congresses (PIANC),Brussels, Belgium, 1996. 76 pp. illustrated, color, with appendices.

Norman R. Francingues, Jr., Chairman of Working Group No. 17.

This particularly timely publication on the pervasiveproblem of dredging in the presence of contaminatedsediments is another in a series of colourful and con-temporary-styled reports from PIANC on dredgingmatters. It was prepared by the collaboration of aworking group of international experts.

PIANC's Permanent Technical Committee (PTC)I established the Working Group no. 17 to examine allpertinent aspects of the problem of handling andtreating contaminated dredged material (CDM) frominland waterways and ports. The Working Group waschaired by Mr Norman R. Francingues, Jr. of the UnitedStates and vice-chaired by Mr Eric Van den Eede ofBelgium. It comprised a prestigious group of expertswho have generated this report in a remarkably shortperiod of time considering the complexity of the sub-ject. The format and presentation is very readable.

Volume I is the traditional PIANC report, albeit in colourand very well illustrated. It intends to provide guidancefor the primary audience of navigation authorities andpermitting and review agencies. Volume 2 which willcontain the technical information and details needed bypractising engineers or other professionals requiringspecifc data and sources of tecnical information, will bepublished later this year.

Volume I is organised into six chapters: 1, Descriptionof the Problem; 2, Sources and Characteristics of CDM;3, Framework for Identification, Assessment, andSelection of Management Techniques for CDM; 4,

Books/Periodicals Reviewed

29

future, both with and without control of contaminantsat their sources. Without source control, the picture isgrim, with the amount of CDM requiring costly treat-ment becoming larger and larger. This should be astrong message.

Of particular note in this regard is Table 2 of Annex I inwhich a fairly detailed description of contaminants andthe industries associated with them is presented. The glossary and the multi-language vocabulary areboth valuable additions to an already excellent report,which offers a wealth of information and excellentreferences in a brief and readable form. Anyone evenremotely connected with the dredging field needs toadd this book to their libraries. We look forward to thepublication of Volume II.This publication can be obtained from the IADCSecretariat in The Hague, or the PIANC Secretariat in Brussels.

Dredging, ICE Design and Practice Guide.Institution of Civil Engineers, Thomas Telford Publica-tions. London, UK. 1996. 67 pp, illustrated with referen-ces. £ 12.50. UK and Europe; £ 15.00 elsewhere, by air.

Denis Yell and John Riddell

The Institution of Civil Engineers (ICE) has as one of itsmajor aims to provide its members with opportunitiesfor continuing professional development. One methodby which the ICE achieves this is through the produc-tion of design and practice guides on topics relevant tothe professioanl activities of its members. As the titleclearly indicates, this book belongs to this series and isdevoted to the practice of dredging, an activity vital tomaritime navigation, international commerce, off-shoreengineering, aggregates for the construction industryand in coastal defense works.

Edited by two well-known dredging experts, the contri-butions included are from some of the leading namesin dredging in the UK. One of the editors, John Riddellof the Department of Civil Engineering at the Universityof Strathclyde in Scotland, is especially recognised as aleader in dredging curricula and education. The principal audience of the ICE design and practiceguides are meant to be practicing civil engineers whoare not necessarily expert in or familiar with the subjectmatter. This guide, following that pattern, could be saidto be a sophisticated primer on dredging for a technical-ly advanced readership. Because of its thrust, it canalso be a educational or familiarisation tool for otherswhere dredging is not their main occupation, but a clearpart of their interest, e.g., port authorities, legislators,regulators, contractors, environmental advocacygroups, educational institutions and such.

Starting right at the beginning, the book discusses thereasons for dredging, the nature of the dredging con-

tracting or operating industry and the types of dredgingprojects. Next the authors describe the specialisedtools needed to dredge; the types of dredgers and thecharacteristics and uses, auxiliary equipment, andcontrol systems for dredgers. The photographs accom-panying the text are excellent.

The authors then elaborate on the cost and productionof estimating aspects of dredging. They cover the mosttypical elements of this, looking at the costs of themain items of dredging plant, eg., hire, insurance,repairs, fuel, lubricants, stores and supplies, andwages. A figure or box is shown which describes thevarious types of dredging equipment and the costelements for each. The importance of position fixingand bathymetric surveys in dredging are discussed andthen the various factors which go into a productionscheme of dredging and their costs are presentedbriefly, but sufficiently enough to give a broad picture.Figure 16 is a flow chart of costs and production esti-mating activities.

Environmental considerations are given a full chapter asis appropriate. Impacts on the environment from dredg-ing operations and disposal activities are discussed, aswell as the international controls. Disposal options andbeneficial use of dredged material is also coveredbriefly.Next the subject of the forms of contracts or agree-ments between the owner of the project and thecontractor or dredging operator is presented. The twoprimary categories of dredging works, capital andmaintenance works, are discussed; and the twostandard forms of contracts employed in the UK: ICE and FIDIC. The need for amendments to thestandard conditions of FIDC when it comes to dredgingworks are mentioned and the availaiblity of the IADCguidelines for FIDIC part two is suggested. Types ofpayment, insurance and tendering procedures arelikewise described.

A chapter is devoted to dredging project design andsite investigation, with basic concepts of channeldesign taking into consideration rates of siltation andcurrents and the complexities of vessel traffic, sideslopes, geotechnical investigations and environmentalsurveys. Though this is a broad area to cover in a shortspace, the authors have met this difficult task well.Finally, the supervision and measurement aspects ofdredging projects are reviewed including: risk manage-ment, duties and responsibilities of the supervisingengineer, quality control, remote supervision, measure-ments of quantity, quality, and time, dredging instru-mentation, and causes of claims and disputes.All and all, this is an effective primer as serves well as an introduction to a particularly technical subject,covering the most important elements of dreding in a


30

continued on page 32

Seminars/Conferences/Events

For further information please contact as soon aspossible:Dr C. H. Pennington, Director, WES Graduate Institute,3909 Halls Ferry Raod, Vicksburg MS 39180-6199, tel. +1 601 634 3549, fax +1 601 634 4180, or Dr. B.L. Edge or Dr. Robert E. Randall, OceanEngineering ProgrammeTexas A&M University, College Station, TX 77843-3136,tel. +1 409 847 8712 / 845 4515, fax +1 409 862 1542.

PIANC Conference on Inland and MaritimeNavigation and Coastal Problems of East European Countries

Gdansk, PolandSeptember 1-5 1996

The Marine Civil Engineering Department of theTechnical University of Gdansk is the site of the PIANC(Permanent International Association of NavigationCongresses) conference on inland and coastal pro-blems in Eastern Europe. The conference will be run-ning simultaneously with Baltexpo. The focus will be on East European waterways and the topics which willbe discussed are:- inland navigation in East European countries and its

link to other countries;- maritime navigation with particular consideration of

shipping in the Baltic, Black, Adriatic and other seas;- competitiveness of navigable waterways;- pollution of seas due to contaminated rivers in

Eastern Europe;- coastal problems such as sediment, beach and

harbour pollution in Eastern Europe;- rehabilitation and modernisation of existing struc-

tures; and- particular areas of shipping such as from

Scandinavian ports to Northeast Europe.

Further information is available from:Prof. B.K. MazurkiewiczTechnical University of Gdanskul. G. Narutowicza 11/12, 80 - 952 Gdansk, Polandtel. +48 58 472611, fax +48 58 471436telex 0512302 plg pl

11th International Harbour CongressAntwerp, Belgium

June 17-21 1996

Organised by the Royal Flemish Society of Engineers,this five-day congress will be held together with the 8thInternational Harbour Exhibiton. Topics will include allaspects of port and harbour technology such as:- port planning: extension, renovation, future policy

making, environment, financing through privatisation;- port infrastructure design: reducing wave agitation;

quality control and care; measurements, instrumen-tation; design in third world situations;

- port construction: innovative techniques, new shiptypes, protection of water bottom;

- port access: approach channels, capital dredging andmaintenance in rivers; and

- maintenance: planning, reducing work on piers,breakwaters; maintenance dredging; emergencyintervention; third world ports.

For further information contact:Ms Rita Peys, c/o Ingenieurshuis, Desguinlei 214B-2018 Antwerp, Belgiumtel. +32 (3) 216 0996, fax +32 (3) 216 0689

Coastal Engineering Education ProgrammeTexas A&M University/CERC

Fall 1996-Summer 1997

A one-year Masters of Engineering programme inOcean Engineering is being offered through theWaterways Experiment Station Graduate Institutejointly by Texas A&M University (TAMU) and theCoastal Engineering Research Center (CERC). Thoughthe course is tailored to meet the needs of the USArmy Corps of Engineers for coastal engineering andmaintenance, all qualified candidates are invited toapply. Applicants must have a BSc in engineering; agood scholastic record; acceptable Graduate RecordExamination scores; and international students mustpass the TOEFL exam. The course will run from theFall of 1996 through the Summer of 1997, and willrequire a minimum of 36 credit hours for the comple-tion of a degree.

Seminars/Conferences/Events

31

Hydro 96De Doelen Congress CentreRotterdam, The Netherlands

September 24-26, 1996

The tenth international biennial symposium of The Hydrographic Society is being organised by The Society's Benelux Branch. The Symposium’stopics will address key hydrographic issues affectingport and other applications, including: port and coastalsurveys; port and coast geodesy and navigation; dredg-ing surveys; mapping; and water management. The proceedings will be supported by an exhibition ofequipment and services at which the Port of Rotterdamwill be a major participant.

For further information contact:Mrs P.Y. van den BergHydro 96 Organising CommitteeOceanographic Company of The NetherlandsP.O. Box 74292701 AK Zoetermeer, The Netherlandstel. +31 7942 8316, fax +31 7941 5084

brief and relatively non-technical manner. Certainly thispublication could also be a very useful tool to instruct avariety of non-dredging audiences in the complexitiesand technologies of dredging.

This publication is available from:Thomas Telford Services Ltd, 1 Heron Quay, LondonE14 4JD, UK; American Society of Civil EngineersPublications Sales Department, 345 East 47th Street,New York, NY 10017-2398, USA; and Maruzen Co. Ltd,Book Department, 3-10 Nihonbashi 2-chome, Chuo-ku,Tokyo 103 Japan.

CUR Manual 169, Manual on the Use of Rock inHydraulic Engineering.Balkema Publishers, Rotterdam, The Netherlands. 1995.800 pp, illustrations and graphs. NLG 485.

Centre for Civil Engineering and Codes (CUR) andThe Netherlands Ministry of Transport, Public Works

and Water Management.

In 1991 as a result of a joint project between CUR andCIRIA (Construction Industry Research and InformationAssociation, UK), Manual 154 entitled, Manual on theUse of Rock in Coastal and Shoreline Engineering, waspublished. This manual has been accepted worldwideas the provisional European Standard concerning theuse of rock. Now a second Manual, number 169, has been issued.It covers the same field as the first, but extends thescope of application to river and dam engineering bygiving guidance on the planning, design, maintenanceand construction of closure works and inland waterwaystructures. The examples presented concern projectsin The Netherlands, Korea, and Bangladesh.Typical “structures” addressed by this manual arebreakwaters, dams, seawalls, bed protection and riverbank protection and training works. All possible “designtools“ are presented, for instance concerning currents,waves, scour, earthquakes, ships, slip-circle analysis,filter rules and hydraulic and geotechnical modelling. The user is also guided through the typical designstages of the structure such as feasibility study,generation and selection of alternatives, construction,environmental assessment, risk analysis, quality assur-ance, materials selection, economy, and optimisation ofthe structure.

Both Manual 154, Manual on the Use of Rock inCoastal and Shoreline Engineering (price NLG 370) andManual 169, Manual on the Use of Rock in HydraulicEngineering (price NLG 485) are available fromBalkema Publishers, P.O. Box 1675, NL 3000Rotterdam, The Netherlands, fax +31 10 413 5947.


32

Books/PeriodicalsReviewed continued from page 30

Call for PapersWODCON XV, “Dredging Into the 21st Century” and Exhibition

Las Vegas, Nevada, USAJune 28-July 2, 1998

This announcement is the first call for papers for thefour-day technical programme and exhibition with thetheme “Dredging Into the 21st Century”. Suggestedtopics include but are not limited to: computerised dredging; dredge automation; disposal ofdredged materials; beneficial uses of dredged material;environmental issues; dredging and the economy.

Interested authors should submit a one-page abstractto the Technical Papers Committee, which will reviewall submissions and notify authors of acceptance.Papers must be submitted to be included in the pro-ceeding which will be published prior to the Congress.Submission deadlines are:Abstracts must be received by October 30, 1997; authors will be notified by December 1, 1997; final manuscripts must be submitted by March 1, 1998.For further information about submitting a paper orabout hiring booth space in the exhibition hall pleasecontact:Executive Director, Western Dredging Association, PO Box 5797Vancouver, Washington 98668-5797, USAtel. +1 360 750 1445, fax +1 360 750 1445 ortel. +1 503 285 5521, fax +1 503 240-2209

AfricaBoskalis Togo Sarl., Lomé, TogoBoskalis Westminster Cameroun Sarl., Douala, CamerounDredging International Services Nigeria Ltd., Lagos, NigeriaHAM Dredging (Nigeria) Ltd., Ikeja, NigeriaNigerian Dredging and Marine Ltd., Apapa, NigeriaWestminster Dredging Nigeria Ltd., Lagos, NigeriaZinkcon Nigeria Ltd., Lagos, Nigeria

The AmericasACZ Marine Contractors Ltd., Brampton, Ont., CanadaBeaver Dredging Company Ltd., Calgary, Alta., CanadaDragamex SA de CV, Coatzacoalcos, MexicoGulf Coast Trailing Company, New Orleans, LA, USAHAM Caribbean Office, Curaçao, NAStuyvesant Dredging Company, Metairie, LA, USAUscodi, Wilmington, DE, USA

AsiaBallast Nedam Malaysia Ltd., Kuala Lumpur, MalaysiaBallast Nedam Dredging, Hong Kong Branch, Hong KongBoskalis International BV., Hong KongBoskalis International Far East, SingaporeBoskalis Taiwan Ltd., Hualien, TaiwanDredging International N.V., Hong KongDredging International N.V., SingaporeFar East Dredging Ltd., Hong KongHAM Bangladesh Office, Dhaka, BangladeshHAM Hong Kong Branch, Wanchai, Hong KongHAM Singapore Branch, SingaporeHAM Taiwan Office, Taipei, TaiwanHAM Thai Ltd., Bangkok, ThailandJan De Nul Singapore Pte. Ltd., SingaporePT Penkonindo, Jakarta, IndonesiaTideway DI Sdn. Bhd., Selangor, MalaysiaVan Oord ACZ B.V., Dhaka, BangladeshVan Oord ACZ B.V., Hong KongVan Oord ACZ B.V., SingaporeVan Oord ACZ Overseas B.V., Karachi, PakistanVomsi India Ltd., New Delhi, IndiaZinkcon Marine Malaysia Sdn. Bhd., Kuala Lumpur, MalaysiaZinkcon Marine Singapore Pte. Ltd., Singapore

Middle EastBoskalis Westminster Al Rushaid Ltd., Dhahran, Saudi ArabiaBoskalis Westminster M.E. Ltd., Abu Dhabi, UAEDredging International N.V., Middle East, DubaiDredging International N.V., Tehran Branch, Tehran, IranGulf Cobla (Limited Liability Company), DubaiHAM Dredging Company, Abu Dhabi, UAEHAM Saudi Arabia Ltd., Jeddah, Saudi ArabiaJan De Nul Dredging, Abu Dhabi, UAEVan Oord ACZ Overseas BV., Abu Dhabi, UAE

AustraliaCondreco Pty. Ltd., Sydney, NSW, AustraliaDredeco Pty. Ltd., Bulimba, QUE., AustraliaJan De Nul Australia Pty. Ltd., Brisbane, QUE., AustraliaNew Zealand Dredging & General Works Ltd., WellingtonVan Oord ACZ B.V., Victoria, AustraliaWestHam Dredging Co. Pty. Ltd., Sydney, NSW, Australia

EuropeACZ Ingeniører & Entreprenører A/S, Copenhagen, DenmarkAnglo-Dutch Dredging Company Ltd., Beaconsfield,United KingdomA/S Jebsens ACZ, Bergen, Norway

Atlantique Dragage S.A., Nanterre, FranceBaggermaatschappij Boskalis B.V., Papendrecht, NetherlandsBaggermaatschappij Breejenbout B.V., Rotterdam, NetherlandsBallast Nassbaggergesellschaft, Hamburg, GermanyBallast Nedam Dredging, Zeist, NetherlandsBallast Nedam Dragage, Paris, FranceBoskalis Dolman B.V., Dordrecht, NetherlandsBoskalis International B.V., Papendrecht, NetherlandsBoskalis Oosterwijk B.V., Rotterdam, NetherlandsBoskalis Westminster Aannemers N.V., Antwerp, BelgiumBoskalis Westminster Dredging B.V., Papendrecht, NetherlandsBoskalis Westminster Dredging & Contracting Ltd., CyprusBoskalis Zinkcon B.V., Papendrecht, NetherlandsBrewaba Wasserbaugesellschaft Bremen mbH, Bremen, GermanyCEI, Bagger- en Grondwerken, Zele, BelgiumDelta G.m.b.H., Bremen, GermanyDraflumar SA., Neuville Les Dieppe, FranceDragados y Construcciones S.A., Madrid, SpainDravo S.A., Madrid, SpainDredging International N.V., Madrid, SpainDredging International N.V., Zwijndrecht, BelgiumDredging International Scandinavia NS, Copenhagen, DenmarkDredging International (UK), Ltd., Weybridge, United KingdomEnka-Boskalis, Istanbul, TurkeyEspadraga, Los Alcázares (Murcia), SpainHAM Dredging Danmark Aps, Korsør, DenmarkHAM Dredging Ltd., Camberley, United KingdomHAM, dredging and marine contractors, Capelle a/d IJssel,NetherlandsHAM-Van Oord Werkendam B.V., Werkendam, NetherlandsHeinrich Hirdes G.m.b.H., Hamburg, GermanyHolland Dredging Company, Hardinxveld, NetherlandsHolland Dredging Iberica S.L., Tarragona, SpainHolland Dredging Co. (Irl.) Ltd., Cork, IrelandHolland Dredging Co. (U.K.) Ltd., Farnham, United KingdomImpresa SIDER SpA., Rome, ItalyJan De Nul N.V., Aalst, BelgiumJan De Nul Dredging N.V., Aalst, BelgiumJan De Nul (U.K.) Ltd., Ascot, United KingdomNordsee Nassbagger- und Tiefbau GmbH, Wilhelmshaven,GermanyN.V. Baggerwerken Decloedt & Zoon, Brussels, BelgiumPhilipp Holzmann Aktiengesellschaft, Hamburg, GermanyS.A. Overseas Decloedt & Fils, Brussels, BelgiumSider-Almagià S.p.A., Rome, ItalySkanska Dredging AB, Gothenborg, SwedenSociedade Portuguesa de Dragagens Lda., Lisbon, PortugalSociedad Española de Dragados SA., Madrid, SpainSocietà Italiana Dragaggi SpA. “SIDRA”, Rome, ItalySociété de Dragage Holland (France) S.A., Bondues, FranceSociété de Dragage International “S.D.I.” S.A., Marly le Roi, FranceSodranord Sarl, Paris, FranceTideway B.V., Breda, NetherlandsVan Oord ACZ B.V., Gorinchem, NetherlandsVan Oord ACZ Ltd., Newbury, United KingdomVan Oord ACZ B.V., Zwijndrecht, BelgiumVolker Stevin Baggermaatschappij Nederland B.V.,Rotterdam,NetherlandsVolker Stevin Dredging B.V., Rotterdam, NetherlandsWasserbau ACZ GmbH, Bremen, GermanyWestminster Dredging Co. Ltd., Fareham, United KingdomZanen Verstoep B.V., Papendrecht, NetherlandsZinkcon Contractors Ltd., Fareham, United KingdomZinkcon Dekker B.V., Rotterdam, NetherlandsZinkcon Dekker Wasserbau GmbH, Bremen, Germany

Membership List IADC 1996Through their regional branches or through representatives, members of IADC operate directly at all locations worldwide.

INTERNATIONAL ASSOCIATION OF DREDGING COMPANIES

Duinweg 21 - 2585 JV The Hague - The Netherlands

Documents

International Journal on Public Works ... - IADC Dredging...importance to the future success of the dredging in-dustry. The full text of the presentations by the speak-ers is available