This Guide Hae Been Prepared By

PANEL M-19 (SHIP TRIALS)

of

THE SOCIETY OF NAVAL ARCHITECTS

AND MINE ENGINEERS

TECHNICAL AND RESEARCH PROGRAW

James E. Corlise, Chairman

Nikos O. Alexiou M. W. Hirschkowitz

Willim G. Bullock Ernest A. Maier

Harmon M. Burford R. E. Willimson

John E. Craft Jmes R. Wittmeyer

D. Richard Gipe

Reviewed and Approved

SHIPS ,

Thomas

John W. Boylston

Norman H. Brubaker

Willim G. Bullock

Harmon M. Burf ord

Allen Chin

Jaes E. Corliss

F. X. Critelli

Allen E. Crout

Charles H. Gross

Joseph D. Hailton

Richard W. Harkins

Carl F. Horlitz

Everett C. Hunt

Chester L. Long

Lisea Ann Martinez

by

MACHINERY CO~ITTEE

P. Mackey, Chairman

Robert M. Morais

Edward F. Murphy

Charles A. Narwicz

Michael G. ParsOne

F. Everett Reed

Alan L. Rowen

John T. Schroppe

Gerald C. Swensson

Andrew A. Szypula

Richard P. Thorsen

Joseph Tiratto

Willim Watson

John D. Willi-s

Charles W. Wilson

Francis M. Cagliari

Deputy Executive Director

.

\\

This Guide Has Been Prepared By

PANEL M-19 (SHIP TRIALS)

of

THE SOCIETY OF NAVAL ARCHITECTS

AND ~INE ENGINEERS

TECHNICAL AND RESEARCH PROG~

James E. Corliss, Chairman

Nikos O. Alexiou M. W. Hirschkowitz

William G“. Bullock Ernest A. Maier

Harmon M. Burford R. E. Willimson

John E. Craft Jmes R. W ittmeyer

D. Richard Gipe

Reviewed and Approved

by

SHIPS < MACHINERY COMMITTEE

Thomas P. Mackey, Chairman

John W. Boylaton

Norman H. Brubaker

William G. Bullock

Harmon M. Burford

Allen Chin

James E. Corliss

F. X. Critelli

Allen E. Crout

Charles H. Gross

Joseph D. Hailton

Richard W. Harkins

Carl F. Horlitz

Everett C. Hunt

Chester L. Long

Lissa Ann Martinez

Robert M. Morais

Edward F. Murphy

Charles A. Narwicz

Michael G. Parsons

F. Everett Reed

Alan L. Rowen

John T. Schroppe

Gerald C. Swensson

Andrew A. Szypula

Richard P. Thorsen

Joseph Tiratto

Willim Watson

John D. Williams

Charles W. Wilson

Francis M. Cagliari

Deputy Executive Directorl\,

.,

TECHNICAL AND MSEARCH BULLETIN 3-47

GUIDE FOR SEA TRIALS

1989

Prepared by

PANEL M-19 (SHIP TRIALS)

of

the

SHIPS , ~CHINERY COWITTEE

Published by

THE SOCIETY OF NAVAL ARCHITECTS AND

601 Pavonia Avenue

.. - Jersey City, NJ 07306

HARINE ENGINEERS

JUNE 1990

Copyright 1990 by The society of Naval tichitects and Marine Engineers

ACKNONLEDGE~NTS

The panel gratefully acknowledges the

contributions of the metiers of The Society, industry

and goverment who have been generous in assisting the

panel in accomplishing its task. The panel also

acknowledges the hours dedicated by Mrs. Ina Fisher in

preparing the numerous drafts reqired before

publication and Mr. E. K. Lee, Jr. for drafting the

illustrations and data sheets throughout the guide.

ABSTWCT

This guide covers sea trials of self-propelled

surface ships displacing 300 tone or more, ~wered by

fossil fuel and driven by stem turbine, gas turbine,

diesel engine or electric motors. It does not cover

dock trials or tests or demonstrations which can be

conducted dockside, which are covered in SNm T&R

Bulletin 3-39, Guide for Shop and Installation Tests.

.:’

ii

PRSFACE

The worldwide use of The

Society of Naval Architects and

Marine Engineers’ (SNU ) code for

Sea Trials - 1973 (Technical and

Research Code c-2 ) dealing with sea

trials and the following

considerations influenced its Ships’: Machinery Comittee, through the. ... Society’s Technical and Research

v -Progrm, to assign to Panel M-19

‘(Ship Trials) the task to expand and

update the code with some assistance

from Panel H-10 (Ship

Controllability) .

(a)

(b)

(c)

The alteration of the

format from ,’code” to

,sgu ideqq.

The need to include

technological advances

in sea trial

instrumentation during

the 15 plus years the

code has been in print,

and also to be

res~nsive to increased

use of diesel engines.

The need to consider the

provieione of the

,>Interti Guidelines for

Estimating Maneuvering

Performance in Ship

Design” contained in the

International Maritime

Organization (IMO)

Circular ~C/Circ. 389,

dated 10 January 1985 as

recommended by Panel H-

10.

The panel consisted of ship

e~ iment test ex~rts fromshipyards, ship designers, ship

Omers, the Maritime Atiinistration,

regulatory bodies and classification

societies. The final draft was

reviewed by the Ships’ Machinery

Comittee consisting of senior

marine engineers from all fields of

interest and the consensus of their

cements appears in the guide as

approved and iesued.

The baeic concept followed in

preparing the guide was to provide

information on a sufficient variety

of sea trials and tests to enable

the owner or acceptance authority to

choose those suitable for the type

of ship and operation involved.

Positive contractual invocation of

specific individual trials is

recommended rather than having them

invoked as a package without proper

consideration. This avoids

burdening the industry with

expensive trials not needed by the

owner.

The guide does provide a list

of those trials recommended as

necessary to demonstrate that the

ship as built and delivered will

perform ae epecif ied. Absence of an

at-sea test or trial from those

recommended does not imply a

negative recomendat ion by the

Society, but merely that the primary

objective of such a test or trial is

to provide design data to meet some

other tiprtant objective, rather

than to prove the ship under trial.

Similarly, the omission of

requirements ia not intended to

negate the value of the efforts

which are directed to verifying

design standards, scale factors, and

margins rather than the

accept~ility of the ship. Some

exaples of omitted reqiremente are

the extensive processing of trial

data and the correcting of trialdata to a design baseline when the

data obtained clearly indicate that

the ship is satisfactory. Such

tests, trials, data processing, and

data correcting should be

separately and specifically invoked

when desired.

iii

Trial recommendations arebased on the assumption that all

operability testing and machinery

checkouts have been previously

conducted at the dock insofar as

conditions at the shipbuilder, s

plant permit.

Methods of analysis of results

from trials are not included herein,

in general, but may be found in the

technical literature and in other

guides of the Society.

Section 1 of the guide

includes general remarks applicable

to any sea trial and provides a

basic recommendation for trials to

be conducted. Sections 2, 3 and 4

provide instructions for sea teste

and trials. Section 5 provides a

brief description of instruments

used for trials and a bibliography

of publications which can be

consulted for detail. It also

includes instructions for

instrumentation peculiar to trials,

in particular torsiometers.

Section 6 establishes a format and

provides illustrative forms for the

presentation of sea trial re~rts.

Section 7 provides definitions of

terms peculiar to sea trials as they

are employed in the guide. It is

advisable to consult the definitions

section in connection with other

sections of the guide.

DISCLAI~RS

This guide is advisory only.

There is no implication of warranty ,,by SN~ that successful performance .

of the recommended trials will

ensure that a ship will comply with w’the re~irements of the contract

specifications, regulatory bodies or

classification societies, or that it

will perform satisfactorily and

safely in service.

The opinions or assertions of

the authors herein are not to be

construed as official or reflecting

the views of SNW or any goverment

agency.

It is understood and agreed

that nothing expressed herein is

intended or shall be construed to

give any person, fire, or

corporation any right, remedy, or

claim against SN* or any of its

officers or metiers.

b

iv

TABLE OF CONTENTS

1.0.-. ..

~ k,

2.0

3.0

INTRODUCTION ..................................................

1.1 Supersession .............................................

1.2 origin ...................................................

1.3 Purple ..................................................

1.4 scope ....................................................

1.5 Trial Object Ives .........................................

1.6 Ship and Environmental Conditions ........................

1.7 List of Trial s and Selection. ............................

1.8 Recognition Of Uncertainty. ..............................

1.9 Planning .................................................

l.lOPre-Trial Checklist. ....................................

1.11 8uilders’ Trials .........................................

PROPULSION PLANT TRIALS... ....................................

2.1 General ..................................................

2.2 Propulsion Plant Economy Triale. .........................

2.3 Propulsion Plant Ahead Endurance Trials. .................

2.4 Propulsion Plant Astern Trial. ...........................

2.5 SWcial Considerations for Ste- Propulsion Plant

Trials .................................................

2. b Special Considerations for Diesel Propulsion Plant

Trials .................................................

2.7 Special Considerations for Gas Turbine Propulsion Plant

Trials .................................................

2.a a~cial Considerations for Electric Drive Propulsion

Plant Trials ...........................................

2.9 Centralized Propulsion Control System Test. ..............

WE~RING ANDaPECIAL TESTS. ................................

3.1 Selection of Teats .......................................

3.2 Preparation ..............................................

3.3 Reports ..................................................

3.4 Ahead Steering ...........................................

3.5 Astern ateering ..........................................

3.6 Auxiliary Means Of Steering. .............................

3.7 Turning circlee ..........................................

3.8 “Z” Maneuver .............................................

3.9 Initial ~rning Tests.... ................................

3.10 Pullout Testa ............................................

3.11 Direct Spiral Test... ....................................

3.12 Reverse Spiral Test.. ....................................

3.13 Thrueter Tests ...........................................

m1

1

1

1

1

1

3

4

5

6

7

9

10

10

11

13

14

15

18

20

21

21

27

27

28

2B

2a

29

29

29

30

32

32

33

34

35

TABLE OF CONTENTS (cent inued )

3.14 Quick Reversal from Ahead to Astern

(stopping Tests )........................................

3.15 Quick Reversal from Astern towhead .......................

3.16 Low Speed controllability Maneuvers .......................

3.17 510w Steaing Ability .....................................

3.18 Anchor Windlase ...........................................

3.19 Distill ing Plant ..........................................

3.20 Miscellaneous Auxiliary Systems ...........................

3.21 Emergency Propulsion Systems. .............................

3.22 Navigation Eqipment ......................................

3.23 Dyn-ic Posit iOning System. ...............................

4.0 STANDARD IZATIONTRIWS. .........................................

4.1 Purpose ...................................................

4.2 Genera l Plan ..............................................

4.3 Trial Area ................................................

4.4 Wind and Sea ..............................................

4.5 Nutierof Sped Points ....................................

4.6 Course Select ion ..........................................

4.7 Operation of the Ship..... ................................

4.8 Data Re~irements .........................................

4.9 Organization of observers. ................................

4.10 Instrumentation for Standardization Data. .................

4.11 Coordination Procedure.. ..................................

4.12 Tolerances and Limits .....................................

4.13 Data Reduction ............................................

4.14 Corrections ...............................................

5.0 INSTRUMENTS AND APPARATUS FOR SHIP’S TRIALS .....................

5.1 General ...................................................

5.2 Tem~rature Measuraents. .................................

5.3 Pressure Measurements .....................................

5.4 “’ Flow Meaaurementm .........................................

5.5 Tor~eand Horae~wer Measur=ents. .......................

5.6 Shaft-Power Meters ........................................

5.7 Shaft Thrustmeters ........................................

5.8 Shaft sped measurements.. ................................

5.9 Vibration Measurement 8....................................

5.10 Airborne Noiae Measurements. ..............................

5.11 Feedwater Teeting .........................................

5.12 Density Measurement8 ......................................

5.13 Leakage Measurements ......................................

5.14 Flue and Exhaust-Gas Analyses. ............................

36

37 -..

37

38 w’38

39

39

40

40

40

42

42

42

42

42

43

43

44

45

46

46

47

47

47

48

49

49

52

53

56

58

59

60 L60

61

63

63

64

64

65

vi

TABLE OF CONTENTS (continued)

5.15 Stea Quality and Purity Measurements ........................ . 5.16 Viscosity Measurements ....................................

.... 5.17 Electrical Measurements ...................................

5.18 Wind Speed and Direction Measurements .....................‘4 .. . 5.19 Radiometric Tracking Systems. .............................

5.20 Time Measurements .........................................

6.0 TRIAL DATA AND REPORT ...........................................

6.1 General ...................................................

6.2 Data Plan .................................................

6.3 Data Crew Training ........................................

6.4 Maneuvering Trials and Special Tests. .....................

6.5 Standardization Trials... .................................

6.6 Fuel Economy, Endurance, Boiler Overload and stem

Rate Tests ..............................................

6.7 Propulsion Plant Trials.. .................................

6.8 Trial Re~rt ..............................................

PROPULSION PLANT OATA .................................................

APPENDIX A TO CSAPTER 6.0, CORRECTING TURNING CIRCLE PLOTS FOR DRIFT. .

A.1 Principle .................................................

A.2 Plotting ~erground. Track. ................................

A.3 Detemination of Drift.... ................................

A.4 Detemination of Drift Rate. ..............................

A.5 Plotting the Drift Corrected Turning Circle. ..............

A.6 Determination of Turning Circle DtienBions. ...............

A.7 Calculation Of Drift Rate un knots ........................

7.0 DEFINITIONS .....................................................

7.1 *neral Tams .............................................

7.2 Propulsion Plant Trials... ................................

7.3 Maneuvering and Spcial Teeta. ............................

7.4 Standardization Trials. ...................................

m67

67

67

6B

69

70

72

72

72

73

73

73

73

73

74

96

107

107

107

107

10B

108

10B

109

111

111

112

113

114

7.5 InstrmentatiOn ........................................... 114

vii

LIST OF FIGURES

l.a

l.b

1.C

2.

3.

4.

5.

6.

7.

8.

9.

10.

11.

12.

13.

14.

15.

16.

17.

18.

19.

20.

21.

22.

23.

24.

25.

26.

27.

RECOMMENDATIONS FOR STEAM PROPULSION PLANT TRIALS ............... 23

RECOMMENDATIONS FOR DIESEL PROPULSION PLANT TRIALS .............. 24

RECOMMENDATIONS FOR GAS TURBINE PROPULSION PLANT TRIALS ......... 25

ACCEPTABLE DEVIATION AND FLUCTUATION TOLE~CE AND READING v“INTERVALS FOR STEAM ~TE TEST DATA ............................ 26

TYPICAL STANDARDIZATION COURSE. ................................. 45

STANDARDIZATION TRIAL TOLERANCES AND LIMITS ..................... 47

STEERING TESTS .................................................. 76

TURNING CIRCLE TEST - RADIOMETRIC OR OTHER PRECISE

TRACKING AVAILABLE ............................................ 77

TURNING CIRCLE TEST - RADIOMETRIC OR OTHER PRECISE

TRACKING NOT AVAILABLE ........................................ 7B

,,Z“ MEUVBR TEST ............................................... 79

INITIAL TURNING TEST ............................................ 80

PULLOUT TEST .................................................... 81

SPIRAL TEST ..................................................... 82

REVERSE SPIRAL TEST ............................................. 83

THRUSTER TESTS .................................................. 84

QUICK REVERSAL TESTS ............................................ B5

LOW SPEED CONTROLLABILITY HANE~R TESTS ........................ 86

SLOW STEAMING ABILITY ........................................... 87

ANCHOR WINDLASS TESTS ........................................... 87

DISTILLING PLANT TESTS.... ...................................... 88

DYNANIC ~SITIONINGSYSTEH TESTS ................................ 89

CENTRALIZEO CONTROL SYSTEM TESTS ................................. 90

STANDARDIZATION TRIALS .......................................... 91

STEAHPROPULSION PLANT ECONOMY TEST ............................. 92

DIESEL PROPULSION PLANT ECONOHY TEST ............................ 93

GAS TURBINE PLANT ECONOMY TEST .................................. 94

NAINPROPULSION TURBINE STEAN P~T TEST ........................ 95

PROPULSION PLANT DATA WITH 80ATA SHEETS ........................ 96

SWPLE PLOT ILLUSTRATING CO~CTION OF TURNING CIRCLES

FOR DRIFT ...................................................... 110

b

viii

GUIDE FOR SEA TRIMS 1989

1.0 INTRODUCTION

. ..,

.. 1.1 SUPERSESSION

‘J-’.;. This Guide for Sea Trials-1989

supersedes the code for Sea Trials-

1973 of The Society of Naval

Architects and Marine Engineers

(SNAME).

1.2 ORIGIN

This Guide was developed by

updating the Code for Sea Trials-

1973 by SN~ Panel M-19 (Ship

Trials) , assisted by Panel H-10

(Ship Controllability) under the

auspices of the Ships i Machinery

Comittee of SN~. Panel M-19 is

composed of repreeentativee of

shipbuilders, ship owners and

operators, Classification Society,

the Maritime Atiinistration and the

U.S. Coast Guard. Publications of

other SNW Technical Panels were

consulted to check compatibility and

various sources in the technical

literature researched for advances

and current trends. The

recomendat ions incorporate -Interim

Guidelines for Esttiating

Maneuvering Performance in Ship

Designn contained in the

International Marittie Organization

(IMO) Circular MSC/Circ. 389, datedi 10 January 1985.

1.3 PURPOSE

The pur~se of the Guide is to

provide ship owners, deB igners,

operators and builders with

definitive information on ship

trials to form a basis for

contractual agreement.

1.4 SCOPE

The Guide covers

self-propelled surface

sea trials of

shius,comeiciil or naval, displacing 300

tons or more, powered by fossil fuel

and driven by stem turbine, gas

turbine, diesel engines or electric

motors. It does not cover dock

trials or tests or demonstrations

which can be conducted dockside.

For these, refer to SN= Technical

and Research Bulletin 3-39. Guide

for Shop and Installation Tests-

19s5.

Nothing in the Guide should be

construed to delete or modify

re~irements of specified regulatory

bodice.

1.5 TRIW OBJECTI~S

A sea trial may have one or

more of the following objectives

depnding on the position of the

ship in its class, the innovative

content of its design, and the needs

or desiree of its ownere.

1.5.1 Demonstration of Operability

The ship propulsion and

control systeme can be show to

Owrate in their design modes onlyat sea, and the shipbuilder and his

customer both benefit from a

demonstrateion of pro-r operation

which verifies the correctness of

construction, manufacture, and

installation.

1.5.2 Demonstration of Performance

The attaiment of maximum

contract levels of power or speed is

particularly important for the first

ship of a class to verify the

adeqacy of the design of the

propulsion plant and its supporting

auxiliaries.

1.5.3 Demonstration of Endurance

Demonstration of ability to

maintain maximum power and speed for

sufficient time to develop

e~ilibrium conditions and to sooperate for the prescribed period

without failure of system components

is important for every ship. It is

assumed that the ability to operate

thus indefinitely or for the design

life will thereby have been

demonstrated, as any functional

inadequacies will have been made

evident by this and other trial

operations.

1.5.4 Demonstration of Economy

Demonstration of the contract

specific fuel consumption is

mandatory when there is a ~nalty

involved or when reqired by the

ship’ s specifications. Att aiment

of the best possible fuel

consumption is important when there

is a bonus involved. When neither

are involved it is still reqired to

determine fuel rate for the first of

a class to verify design and for

subse~ent ships to verify propr

operability of the energy conversion

system.

1.5.5 Demonstration o~

Controllability

Demonstration that a vessel

has maneuvering qalities ~mitting

course keeping, turning, checking

turns, operating at acceptably slow

speeds, and stopping in a

sat isfactory manner is imprtant for

every ship.

1.5.6 Provision of oDerat Lna Data

It is desirable to establish adata baseline for a new class of

ships and to a lesser degree for

individual ships so that ship

operators will have a standard with

which to compare current operating

data, enabling them to monitor plant

performance.

Ship pilots as well as

Owrators alSO need to know thecontrollability characteristics of v’the vessel. IMO Resolution A. 6D1

provides a comprehensive guide to

providing such data in a standard

format.

1.5.7 Provision of Forensic Data

It is increasingly important

for ship operators to have available

certifiable data on the ship, s

maneuvering capabilities in the

event the ship is involved in legal

action for collision d-age. Data

from other ship systems may be

pertinent to litigation involving

habitability, safety or pollution

responsibilities.

1.5.8 Provision of DeSian Data

A1l trial data au~ents the

bank of design data on which naval

architects and marine engineers

draw, but special data to verify the

euccee6 of an innovative feature or

to advance the state of the

shipbuilding art may be called for.

In such cases it is ti~rtant that

the design authorities who will use

the data specify requirements in

detail, including instrumentation,

OPrating conditions, andb

procedures. The IMO, for instance,

ia gathering data on ship

maneuverability in its developing

and refining of standards and has

detailed s~cific maneuvers that are

included herein.

1.5.9 Classification and Safett

Rem irements

Classification societies and

safety authorities often rewire

demonstration of eqipment and

systems which affect safety of the

ship, its cargo or its crew.

1.6 SHIP AND ENVIRON~NTAL

CONDITIONS

‘t ‘“Proper ship and environmental

conditions during trials are often

critical for achieving useful

results.

1.6.1 Ship and Environmental

Conditions

Trials will generally be

carried out in the loaded condition

where this is possible.

Contractor’s Sea Trials, however,

will usually be performed at other

drafts. Separate trials in the

ballast condition may be rewired.

In selecting ballast drafts for oil

tankers, for uniformity,

cons iderat ion should be given to

those specified by IMCO 1973 MARPOL

for designed ballast draft

capability for tankers.

In all cases, the fore and aft

drafts at the time of the trial must

be recorded. For shipe not provided

with full draft ballast capability,

trial drafts will not approximate

maximum design draft, and

demonstrations of cap~ilities that

are draft de~ndent, such as ship’ e

s%ed and maneuverability, are oflimited value. In such cases it is

A advisable to spcify model tests at

anticipated trial drafts as well as

maximum design draft, aa without

such tests, extrapolation of trial

results depends on uncertain

estimates. Trials should be

conducted at drafts as close as

practicable to the model test

condition. In the abeence of model

test data, standardization at other

than maximum design drafts is not

recommended.

1.6.2 Water Depth

The most demanding

requirements for many ships are met

in shallow water during coastal and

port navigat ion. Unfortunately,

this conflicts with the usual

practice of performing ship trials

in deep water for standard iza-

tion and comparative purposes. Theadeqacy of a ship, s capabilities in

shallow water, particularly

maneuvering, must usually be

inferred from its succese in deep

water, and from its deep water

characteristics relative to other

vessels.

Ships interact with the

bottom, with banks, and with other

veseele with an effect on ship

movement. Trials should therefore

always be made in deep unconfined

waters where possible.

To minimize the possibility of

such effects on the undemay

performance trial results of the

ship, water depth, other than for

s~cial trials to investigate

shallow water capabilities, should

always exceed five times the mean

draft of the ship. During speed

trials additional depth is needed

based on sped and vessel fullness.

From DnV Nautical Safety-Additional

Classes NAUT-A, NAUT-B, and NAUT-C,

July 1986, the following guideline

is recommended:

H > 5.0 ~ and

H > 0.4 V2

where:

H = Water Depth (m)

Am = Midship Section Area (m2)

V = Ship, s Speed (m/see)

1.6.3 Wind, Waves, and Currents

The uncontrollableenvironmental conditions of wind,

waves, and currents can

significantly influence the results

of all underway trials. The effects

are also difficult to account for.

Trials should thus be held in the

calmest weather conditions

available. Wind direction and speed

should be noted at the start of each

test, so that the effects can be

studied and corrections applied.

Currents, wave and swell conditions

and their change should also be

noted.

Sea State 4, significant wave

height up to 2. 5m, should be

avoided. Sea State 3, significant

wave height up to 1.25m, should be

avoided for ships under 500 feet in

length.

Wind speda of more than 10

m/second, 19.4 mifhr, should be

avoided. Maneuvering epiral tests

and slow speed trials are

particularly sensitive to wind and

currents. Wind speed should not

exceed around 5 m/second, 9.7

mifhr, to assure useful results

from such trials.

The recommended tests are:

Economy Triale

Endurance Trials

Astern Trial

Main Turbine stem Rate

Boiler tierload

Centralized Propulsion Control System

Ahead Steering

Astern Steering

Auxiliary Means of Steering

1.7 LIST OF TRIALS AND SELECTION

Slanket invocation of this

Guide is not intended. Sufficient

trials and tests are included to

enable the user to eelect a sea

trial or test of any degree of

complexity desired, but invocation

of the total Guide without regard to

the objectives to be served or the

utility of data obtained would

result in costs incommensurate with

value. Users should study the

Guide, and specify by nutier in the )’

ship, s specifications the paragraphs

covering the trials and tests

reqired to meet their objectives.

Lists of trials and testsrecommended for first-of-a-class and

follow-on ships are provided for

convenience. If this Guide is

invoked by contract, all of the

reco~ended trials and tests are to

be conducted except for those

specifically deleted, and trials or

tests marked ‘If Elected,, are to be

conducted only if specifically

invoked.

Listed below are the Naes of

teats covered in this Guide. The

recommendations associated with the

naes are provided to assist in

developing a trials progr~.

Further guidance on the purpose of

each test and when it is useful may

be found in the column titled Guide

Paragraph.

Recommendation

First of a Class Only

All Ships

A1l Ships

If Elected

If Elected

All Ships

All Ships

All Ships

All Ships

W

ParaaraDh .

2.2

2.3 \

2.4

2.5

2.5

2.9

3.4

3.5

3.6

_W Recomendat ion ParaaraDh

Turning Circles First of a Class Only 3.7Z Maneuver First of a Class Only 3.8Initial Turning First of a Class Only( 1) 3.9Pul lout First of a Class onl~Direct Spiral First of a Class OnlyReverse Spiral If Elected(2)Thruster First of a Class OnlyQuick Reversal from Ahead to Astern All Ships

-, Quick Reversal from Astern to Ahead A1l Ships,Low Speed Controllability Maneuvers

JIf Elected

Slow Steming Ability All ShipsAnchor Windlaes All Ships

Distilling Plant All Ships

Miscellaneous Auxiliary Systems If Elected

Emergency Propulsion Systems If Elected

Navigation E~ipment All ShipsDynmic Positioning System All ShipsStandardization Trials First of a Class Only

(See paragraph 1.5.2)

(1) Derived from paragraphs 3.7 and 3.8

(2) Alternative to ‘rDirect Spiral,,

3.10

3.11

3.12

3.13

3.14

3.15

3.16

3.17

3.18

3.19

3.20

3.21

3.22

3.23

4.0

1.8 RECOGNITION OF UNCERTAINTY

Although ship designers,

builders, and trial ~rsonnel may

exercise the greatest diligence in

pursuing their arts at their most

advanced state, there is inherent in

the mensuration of ship ~rformance

an unavoidable uncertainty. No

measurement is perfect and shipboard

conditions preclude the use of the

most precise techni~es. Since themajor ship prfomance paraeters

involve measurement of many

fluctuating ~antities, each with an.,element of uncertainty, the

cumulative effect might be

J considerable. By applying

probabi 1ity techni~es to the degree

of fluctuation and the inherent

prevision of the instr~ents

involved, including their

calibration, it is pssible to

identify the degree of certainty

with which a ship, s prfomance can

be determined. It is important that

all parties to a ship construction

progrm recognize the uncertainty of

trial results and take it into

consideration when establishing

performance target/bonus/penalty

levels.

Knowledge of how and how much

the prevision of the individual

measuraents affecte the performance

determinantion and the range of

precision avail~le for the

instruments involved enables the

trial planner to make an intelligent

and economic decie ion on

instrumentation.

Reference (d) of Section 5:

“Guidance for Evaluation of

Measurement Uncertainty in

Per fOmance Tests of stem Turbiness,

published by the ~erican Society of

Mechanical Engineers sets forth

methods and exaples prtinent to

land based stem turbine tests which

take place under conditions

approaching a laboratory. The

method of reference (d) should be

consulted when calculating

uncertainty for trials set forth in

this Guide.

1.9 PLANNING

From award of a contract until

delivery of the official trial

report, sea trials reqire

planning. Trial instrumentation

re~irements should be incorporated

in design; prearrangements may be

rewired for obtaining and

calibrating trial instruments; trial

readiness checks should be included

in production planning; trial data

ac~isition, processing, and

reporting systems should be

developed, installed and checked;

instructions and procedures should

be developed for trial operating and

data crews; and these crews should

be trained.

These act ions have an optimum

time of accomplistient beyond which

there is added expense and

disruption.

A prere~isite to all planning

is a clear understanding as to the

tests and trials to be conducted,

the depth of instrumentation and the

data to be reported. If this Guide

is pro~rly cited in the ship- s

specifications, re~irements should

be clear, but if the Guide is not

cited or there remains an area of

doubt, the shipbuilder, ower and

goverment author itiea, if involved,

should reach agreement aa soon as

~ssible after the award of a

contract, using this Guide as a

basis for understanding.

Presuming that agreement hae

been reached, the actions outlined

below can be taken as applic~le.

1 .9.1 Desian Accommodation

(a)

(b)

(c)

(d)

If a torsionmeter is to

be installed, it should

be located on the

shafting and provided

with adeqate clearance.

If repired, special

finish and dimensional

constraints should be

imposed. If the shaft

is hollow, the supplier

of the rough machined

unit should be alertedb’

to provide precise

internal diameter

measurements. Mount ing

of signal transfer

e~ipment or brush

rigging should also be

considered.

If special trial fuel

meters or condensate

meters are to be

installed, systems

should be designed to

accommodate them.

If special gages,

thermometers or orifices

are to be installed,

sensing points should be

selected and the

necessary fittings,

wells or flanges

provided.

If fuel oil saples are

to be taken during

trials, a empling

connect ion or method

should be provided.

1.9.2 Pre-ArrangementsL

(a) If the shaft is to be

calibrated, the shafting

production schedule

should be adjusted to

provide a calibration

availability; the

. (b)

(c)

(d)

(e)

(f)

(9)

(h)

torsiometer should be

reqested if furnished

by the goverment, or

procured or overhauled

if furnished by the

contractor; the torqing

gear should be made

ready, the calibration

accomplished and the

instrument factors

established.

Plant o~rating

conditions including

trial drafts should be

established for each

trial and the owner’s

concurrence obtained.

Plant operating and

ship, s ballasting and

deballasting

instructions should be

prepared and distributed

to trial crew

supervisors.

Signal system should be

deeigned and installed.

Correct ion factors

should be obtained and

the concurrence of

owner’s technical

represent atives

established.

Data instructions and

station bill should be

prepared and

distributed.

Spcial trial

instruments should be

installed and all

instruments which will

provide trial data

calibrated, “red line”

eettings made and “water

legs-. meaeured.

Data fores should be

prepared and checked

against the ship as

built, preferably by

(i)

(])

(k)

(1)

(m)

(n)

using them for Dock

Trials.

Trial operating crew and

data crew should be

trained unlees

previously trained or

experienced.

Calculation sheets

should be prepared, with

dumy calculations and

correction tables or

plots provided.

Radiometric tracking

system, if to be aboard,

including antenna should

be installed and

checked.

A saple of the fuel

expected to be burned

should be sent to a

laboratory for gravity

and heat content

determination when fuel

rates are to be

calculated.

Trial agenda, procedures

and schedules should be

prepared and furnished

to the owners for

cement.

Trial control and

computing center ahou Id

be planned and

facilities installed,

including

communications,

reference material,

calculators and other

trial e~i~ent as

agreed.

1.10 P~-TRIfi C~CK LIST

So many items are involved in

determining readiness for sea trials

that it ia virtually necessary to

use a check list. Such a list would

include the following as applicable:

1.10.1 Operability Check-off

A list of ship’ s machinery to

be used on the trial should be

prepared and operability of each

item established and checked off.Unless dock trials were performed

within two weeks of sea trials it is

advisable to activate the propulsion

plant and check operability of

systems and equipment within 48

hours of departure.

1.10.2 Instrument Installation and

Calibration

Instruments to be used for

trial data should be listed,

inspected for dmage and checked for

proper installation, and

availability of calibration data,

water leg data and ,,red line’,

settings determined.

1.10.3 Torsiometer Readiness

(a)

(b)

(c)

(d)

Check visually for

proper instal lat ion,

cleanliness of slip

rings, proper engagement

of brushes, and proper

clearance of signal

transfer e~i~ent.

Make a pre-trial check

of transformer ratio or

gage factor.

Obtain jacking zero and

aet indicator.

During dock trial or

pre-trial plant

o~rability check,

verify o~rability of

torsiometer.

1.10.4 Document Check

(a) Toreiometer constant

and SHP fomula.

(b)

(c)

(d)

(e)

(f)

(9)

(h)

(i)

(])

(k)

Plant operating

instructions and

checkoff lists.

Data system operating

instructions.

Data forms and

calculation forms.

Fuel gravity and heat

content re~rt.

Fuel temperature/gravity

plots or tables.d

Instrument calibration

records and correction

factors.

Correction factors for

non-standard conditions.

Data crew instruct ions.

Trial agenda, procedures

and schedules.

Selected drawings and

diagrms.

1.10.5 Sianal Svstem ODerabilitX

A pre-departure check should

be made of the signal system at all

stations including telephones.

1.10.6 Radiometric Svstem

~erability

A pre-trial check of the

radiometric eyetem including each

element and its standby should be

made using the trial antenna and

ship’s power. Complete the check

prior to departure if shore stations ‘

are in range; othemise perform it

as soon as the ship comes within

range.

,!.

1.11 BUILDERS< TRI~S

If builders’ trials or runs

are to be conducted, they should be

specified. If data for any portion

of the trial or runs is to be

presented for acceptance, the

owners, acceptance authorities, and

involved regulatory bodies should be

notified in advance. If builders’

trials are not specified, they are

to be at the discretion of the

builder for any purpose, including

- any. of the following:

Checking the operation of the

machinery installation and the

trial e~ipment.

Training the operating and

trial personnel.

Making adjustments to the

plant to establish proper

operation.

Determination of ability to

meet performance re~irements.

.

2.0 PROPULS ION PLANT TRIALS

2.1 GENE~

2. 1.1 Scoue of This Section

This section contains

recommendations for conducting stem

turbine, diesel engine and gas

turbine propulsion plant trials with

the ship underway under specified

conditions. The propulsion plant is

considered to include propulsion

plant machinery, all auxiliaries and

systems repired for its operation

and other such power-using and heat

apparatus as are specified necessaryfor the operation of the ship under

trial conditions. The instructions

herein are intended to cover testing

of the propulsion plant as an

integrated system underway and do

not cover ship or shop teets of

individual e~ipment items, dock

trials or dockside teste rewired by

specifications or regulatory bodies,

unless prescribed herein as

incidental to the trials.

Spcific re~irements for

these types of propulsion plants can

be found beginning with paragraph

2.2.

2. 1.2 SXcific Objectives

Specific objectives of

propulsion plant trials may be one

or more of the following:

To demonstrate satisfactory

OFration of the propulsion plantfor a s~cified ~riod of time at

specified horsepower, usually

maximum design horsepower.

To determine the rate of fuel

consumption of the plant when

operating at specified shaft

horaepwer and other specified

operating conditions.

To detemine performance

characteristics of the machinery

plant or compnents thereof, as

agreed.

To demonstrate satisfactory

operation of propulsion plant

controls from all stations.

To obtain propulsion plant data for

future use in evaluating service

~rfomance.

Note that the power level of the

propulsion plant may be specified in

terms of revolutions per minute when

trial draft or other conditions make

full Fwer unattainable within ehaft

s~ed lbitations.

2.1.3 Pre-Trial Agreements

Prior to the trials, there

should be a clear understanding with

res~ct to the following:

The spcific objectives of the

trials.

The trial agenda and tentative

schedule.

Conditions and met hods of operation

during the trial.

Correct ions, if any, to be applied

for deviations from apcif ied

conditions or spcif ic standards.

10

Measurement methods, temporary te$t

e~ipment and instrumentation.

Trial drafts.

Duration of each trial run.

Fre~ency of readings and

measurements.

2. 1.4 Trial Preparations

Preparation for propulsion

plant trials as defined in thie

section should include the

following:

Calibration of shafting to determine

modulus of rigidity; if the shaft is

not to be calibrated, then an

agreement on the modulus to be used.

Installation and calibration of

toraiometer.

Calibration of trial fuel meters.

Where ships meters are used as trial

or trial back-up instrumentation,

they should also be calibrated.

Calibration of special gages and

meters. Records of calibrations

should be available prior to trials

and carried onboard during trials.

Installation of trial e~i~ent as

re~ired.

Ascertaining that all machinery and

ew iPment iS in propr workingcondition.

Preparation of the trial ballasting

plan to provide the prescribed

submergence of the pro-l ler.

Control and records of fuel onboard

to provide for trials a homogeneous,

known, supply.

Analysis of the fuel to be burned

including heating value, spcific

gravity, viscosity characteristics

and other pert inent proprt ies.

2 .1.5 Trial Duration

Duration of each Propulsion

Plant Trial should be as set forth

in Figures la, lb, and 1.c unless

otherwise specified or agreed.

unless otherwise agreed, any

run, which has been interrupted by

machinery casualties necessitating

slowing down or stopping, should be -

entirely rerun. If the interruption

of a run is due to operating error:..

or maneuvering from the bridge due

to traffic or other safety

situation, only the disrupted

portion of the run need be repeated.

2.2 PROPULSION PLANT ECONOMY TRIMS

2 .2.1 Purpose

The primary purpose of Economy

Trials is the determination of fuel

consumption. An ancillary purpose

is to establish an RPM/SHP

relationship under trial condit ions.

2.2.2 ODeratina Conditions

Uniform operating conditions

should be maintained throughout each

trial run. To establish steady

operating conditions for economy

measurements, a period of warming up

or adjustments should be allowed

prior to trial runs. Steady-state

conditions should be proven prior to

starting economy trials.

Helm changes should be held to

a minimum and course changes should

be made with no more than 5 degrees

rudder..

2.2.3 Freaencv of Observations

Unless othemise agreed,

observations and instrument readings

should be taken at fifteen minute

intervals. Readings of tor~e or

shaft horsepower should be taken as

rewired for producing, as nearly as

is practicable, a continuous record,

11

which will be averaged at 15-minute

intervals. See Figures la, l.b and

1.c for reading intervals for

important data.

2 .2.4 Sianals

Visual and/or audible signals

should be provided to mark the

beginning and end of runs and to

synchronize data taking. Lights,

bells or horns should be located in

the machinery space and at the.’ computing station for easy

observation by all participants.

signals should be controlled from a

central station: The ship’s general

alarm system should not be used for

signaling.

2.2.5 Measurements and

Instrumentation

(a) General. Trial

observations should include all

pertinent time intervals, pressures,

tem~ratures, flow rates, levels,

revolutions, cofiustion conditions,

and other characteristics of

o~rat ion, as may be rewired to

satisfy the trial object ives..

For information concerning

trial instrumentation, see Section

5.0, Instrwents and Apparatus for

Ship’s Trials.

For data reprt ing fores

listing recommended trial

obaervat ions, see Section 6.0,

-. Trial Data and Re~rt.

(b) -. Method of

determining shaft horse~wer should

be as agreed before trials.

Suitable measuring apparatus,

methods of measuring, and methods of

computing shaft horse~wer are given

in Section 5.0, Instrumentat ion and

Apparatus fOK Ship’ s Trials, but itis not intended to limit or restrict

the use of the measuring e~ipment

to types described therein.

Measurements of auxiliary

electric power should be made by

ships instruments unless otherwise

agreed. For major apere loads,

clmp meters should be utilized to

determine loads where meters are

not fitted.

For ships on which hotel loads

are relatively large, provision for

separate measurements of total

auxiliary machinery loads and hotel

loads is recommended.

(c) Revolutions. Accurate

and reliable trial shaft counters

suitably interfaced with the trial

signal system or data reduction

system should be installed and

checked out prior to the start of

the sea trials. For details ofshaft revolution counters, see

Section 5.0, Instrument and

Apparatus for Ship, s Trials.

(d) Fuel Measurements.

Meaauremente of fuel ~antity should

be made by flow rate meters, which

should be calibrated before and

after trials and the calibration

correction applied to the observed

trial data. For further details on

the installation of trial fuel

meters, refer to section 5.0,

Instruments and Apparatue for Ship’ 5

Trials.

(e) dther Measurements.

Measurements of pres8ure and

temperature which materially affect

trial results should be obtained

from calibrated te8t gages and

thermometers installed for the

trial. Data from ship, s gages,

thermometers and instruments may be

used for trial purpses provided

these instruments have been

calibrated and set to read correctly

in the o-rating range.

12

Acceptable instruments for

time measurements are described in

Section 5.0, Instruments and

Apparatus for Ship’ s Trials.

Measurements of water flow,

when rewired, should be made with

calibrated water meters installed

for this purpose. Ship’ s installed

meters may be used if calibrated.

2.2.6 Fuel Rate Data Reaired

The fuel rate for all purposes

should be expressed in pounds per

shaft horsepower per hour or other

agreed standard units for each trial

run. See Figures 22, 23 and 24 for

Data Sheets. The fuel rate should

be determined from averages of

readings recorded at fifteen (15)

minute intervals and data obtained

from other sources as indicated in

the following:

(a) Fuel meter readings at

start and at end of each

trial interval.

(b) Fuel meter correct ion

from meter calibration

curve.

(c) Fue 1 temperature at the

meter.

(d) Gravity of fuel related

to spcific gravity of

water at 60° F.

(e) Table or plot of

weight /volme for the

range of metering

temperature expacted,

applicable to the

gravity of fuel being

burned.

(f) Higher heating value of

fuel from laboratory

tests or lower heating

value as agreed or

spacif ied.

(9) Average shaft horsepower

for each trial interval.

(h) Fuel chemistry, if

specified.

Note: This should be

determined by post trial

analysis of a thorough mix of

fuel smples taken at a

minimum of four e~ally spaced -

intervals during the run.

2 .2.7 Fuel Rate Calculation .

The fuel rate for all purposes

should be expressed in pounds per

shaft horsepower hour or other

agreed standard units for each trial

run.

2.2.8 Trial Reuort

See Section 6.0, Trial Data

and Re~rt and Figure 26.

2.3 PROPULS ION PLANT AHEAD

ENDU~CE TRIALS

2.3.1 Purnose

The primary purpose of Ahead

Endurance Trials is to demonstrate

eatiefactory ahead opration of the

propulsion plant at specified

operating conditions as

contractual ly re~ ired or agreed.

This should include specific shaft

horse~wer or revolutions per minute

for a prescribed ~riod of the.

since satisfactory operation

and ~rfomance of the machinery

plant is e~ally essential for

endurance and economy trials, they

may be conducted concurrently when

s~cifications for both are the sme

for shaft horse~wer, pariod of run

ttie and fuel. For Endurance Trials

the emphasis is on attaining and

sustaining the rewired power level,

and fuel rate is a secondary

13

interest. For Economy Trials the

fuel and power data are the

essentials, and other data including

auxiliary load levels are used to

explain results to correct for Of f-

standard conditions.

Sometimes Endurance Triale are

specified to include a demonstration

of satisfactory operation of the

., propulsion plant under service

conditions during a specified voyage-.of the ship. Such trials and the

. . details thereof are subject to

agrkement between the parties

involved and are not covered by this

section.

2 .3.2 Measurements and

Instrumental ion

Economy Trial instrumentation

and data systems are generally

ade~ate for Endurance Trials. When

both trials are specified, the

re~irements and discussions of

paragraph 2.2 apply. When only

Endurance Trials are specified,

paragraph 2.2 is applicable, except

that special fuel meter calibration

may not be rem ired and ~wer level

may be detemined without use of a

torsiometer as discussed below.

However, it is recommended that a

torsiometer be used for at least

the first ship of a class so that

corrections to the alternative

methods discuseed below can be

developed both for future trials and

for use in checking service

prf omance.

. .When a torsiometer is fitted,

pwer should be derived from the

average tor~e and mM for the trial

period as set forth in paragraph

2.2. However, u~n agreement or by

SFCifiCatiOn, torsiometers may beomitted and pwer approximated from

one or more of the following:

(2) On ships with direct

drive, prime mover

parameters and

conditions, a“d

manufacturer 8s shop test

or design data.

(3) On ships with electric

drive, electrical input

to the propulsion

motor (s) with

manufacturer’s data on

motor efficiency and

power consumption of

shaft-driven

auxiliaries.

Even when trial power isdetermined by use of a torsiometer,

a comparison should be made with

power derived from engine data,

particularly where a torsiometer is

not to be permanently fitted.

2.3.3 Trial Remrt

See Section 6.0, Trial Data

and Report and Figure 26.

2.4 PROPULSION PLMT ASTE~ TRIAL

2.4.1 Purwse and Procedure

The primary pur~ee of the

aetern Endurance Trial ie to

demonstrate satisfactory astern

operation of the propulsion plant at

s~cified oprating conditions ae

contractually rewired or agreed.

This should include specific shaft

horaepwer or revolutions per minute

for a prescribed pried of the. An

ancillary benefit is proving the

ade~acy of piping eupwrts, and

ewiwent under severe vibratoryconditions.

Difficulty in obtaining

unifom pro~ller loading because of

submergence variations due to ship

(1) PrOpller revolutions

-r minute with model

test data.

14

pitch, wave impingement or the

uncontrollable circular track

generally followed when a single-

screw ship is under sternway, often

prevents 5teady propulsion plant

operation. It is therefore

advisable to establish limits to

astern RPM and prime mover

paraeters. As a result, the

average indicated shaft horsepower

for the astern run may be more or

less than the target value.

Some ship specifications will

limit sternway to that speed where

by maximum rudder movement from

hardover will not result in rudder

tor~e exceeding the maximum

specified. In such cases the

maximum astern speed should be

established during the astern run by

incrementally advancing propeller

speed until steering engine

pressures indicate the maximum

rudder tor~e specified.

Except as rewired for astern

steering trials, the rudder should

be held aidshipe during astern

trials.

2 .4.2 Measurement and

Instrumentation

Instrument at ion and the data

system should be the sme as that

for Ahead Endurance Trials. When

stem turbinee are the prime mover,

maximum temperatures should be

monitored carefully.

2.4.3 Trial ReDort

See Section 6.0, Trial Data

and Reprt and Fi~re 26.

2.5 SPECIAL CONSIDERATIONS FOR

STEM PROPULSION PLANT TRIALS

This eection addresses sea

trial related tests which are

~culiar to the stem propulsion

plant.

2 .5.1 Main Propulsion Turbine Steam

Rate Test

2.5.1. (a) Purpose. The purpose of

this test is to determine the non-

extraction steam rate of the

propulsion turbine at the specified

power.

2.5.1. (b) Procedure. The stem

rate test should be run for not less

than one hour under steady-state

conditions. A1l valves and

connections which affect the .

propulsion turbine stem flow should

be listed and their position or

condition specified in advance.

Generally, all turbine extraction,

induction, drain and other valves

affecting measured flow should be

closed. Means should be provided so

that the status of all valves and

connections can be readily

determined and monitored during the

teat. Should it be neceesary for

Oprating reasons to introduce orextract fluid from the main stem

system or condensate/feed system in

such a way as to affect turbine

ste= flow measurements, then the

~antitiee should be measured or

calculated pr advance agreement.

The test conditions should

duplicate the spcified design

conditions of the propulsion

turbine. Unavoidable trial

conditions may result in deviations

for the design conditions, and the

stem rate correction factors for

such off-design conditions should be

supplied by the turbine manufacturer -

yr advance agreement.

The stem rate test ~riod

should be preceded by a stabilizing

~riod of at least one-half hour

during which the the plant

OpratiOn and the prt inent data can

be reviewed and detemined to be

satisfactory to begin the test.

15

The stem rate should bedetermined from the averages of data

recorded during the teat period.

The data, which has a direct

influence on the stea rate

determination, should be recorded at

10 minute intervals and include but

not be limited to that stated in

Figure 2. steady-state conditions

are established when the

fluctuation of a reading from the

average for the trial period does.not exceed the values stated in

* ~igure 2. Satisfactory design

conditions are attained when the

average values for the test period

are within the deviation of

allowance of Figure 2.

2.5.1.(c) Measurements and

Instrumentation. This test rewires

precise measurements of the shaft

horsepower, propeller speed, stem

flow, and the turbine inlet and

exhaust stem conditions. To this

end, the ship’ s instrumentation

should be au~ented with

instrumentation of known accuracy

and calibration.

The method of measuring power

and RPM should be the sme as that

rewired for Economy Trials,

“Recomendatione for SteMl

Propulsion Plant Trials, “ Figure

la.

stem flow should be

determined by stew floweter or

orifice installed in the turbine

inlet piping, flometer or orifice

installed. in the condensate line

‘after the condensate pwp, or by

first-stage nozzle preeeure

measurements. Condensate meters,

orifices, or nozzles should be

calibrated and installed as agreed

or s~cified prior to the test. The

measured par=eters and coefficients

of stem orifices or nozzles should

be established arid agreed to prior

to the test.

Condensate pump flow should beregulated so as to maintain hotwell

level in the gage glass at a

preselected mark thereon. The levelshould be maintained at the

preselected mark prior to reading

the condensate meter.

The turbine stem inlet

condition should be determined with

a calibrated test gage and

thermocouple installed in a section

of the inlet piping away from the

flow effects of valves and turns.

The turbine exhaust pressure

should be determined by absolute

pressure gages or thermocouples

thermometers installed adjacent to

the turbine exhaust flange

connection and either in the turbine

exhaust cylinder or condenser inlet

neck.

Other trial measurements

should be determined by ship, s

instrumentation.

2.5.1. (d) ~. The report

should show the test value and

corrected value of shaft horsepower,

RPM, and stem rate. The deviation

of average values from design and

correction factors applied should be

set forth.

Methods of calculating stem

flow and stem rate from the

observed test data should be

propsed by the shipbuilder,

endorsed by the turbine

manufacturer, and agreed to by the

acceptance authority prior to the

teet. See SN~ Sulletin 3-17,

“Recommended Practice for Correcting

Stem Power Plant Trial

Performance, “ for methods and

standards. Methods of calculating

the shaft horsepower should be the

sae as for economy trials. See

Section 6.0 for Trial Data and

Report.

16

2.5.2 Boiler Overload Test

2.5.2.(a) PurDoae and Procedure.

This test is designed to demonstrate

satisfactory operability of the

boiler and its auxiliaries at

overload capacity and to locate for

correction any caeing and uptake

leakage which might not appear at

lower rates. Demonstrations of the

first make of each manufacturer’s

boiler is generally sufficient to

determine ade~acy of the design.

The test should consist of the

operation of the boiler, a8

indicated in Figure la, at a

prescribed firing rate calculated to

give the rewired overload ste-

Output .

In order to expedite the test

it is advisable to convert the

overload firing rate, furnished by

the boiler manufacturer in terms of

weight/volume of standard fuel, to

volume of the fuel in use. This is

done by applying factors for meter

calibration, fuel gravity at

metering temperature and heat

content. To allow for any off-

standard fuel measurement condition,

a slight margin should be added to

the calculated figure to obtain the

target weight /volume.

Feed temperature, cofiustion

air temperature and volume, oil

tem~rature at burners and other

operating condition which might

affect boiler o-ration should be

adjusted a’s closely as possible to

the manu facturer, s recommended

values.

The method of consuming the

stem generated during the boiler

overload test should be agreed in

advance. This is particularly

im~rtant for single boiler ships

where the propulsion plant will not

consume all of the boiler overload

output .

2.5.2.(b) Measurement andInstrumentation.

(1) When an economy trial

has not been specified,

it is acceptable to use

the ship, s fuel

meter (s) , provided that

suitable manufacturer ,s

calibration curves are

available, to determine

fuel flow to the boiler.

(2) All ship, s gages, tcalibrated as agreed or

specified, are

acceptable for this

test.

2.5.2.(c) Trial Data Remired. The

fuel rate for each trial run should

be determined from the averages of

readings recorded at 15-minute

intervals and from data obtained

from other sources as indicated in

the following:

(1) Fuel meter readings at

start and at end of each

data interval.

(2) Fuel meter correction

multiplier from meter

calibration curve.

(3) Fuel temperature at the

meter.

(4) Gravity of fuel referred

to specific gravity of

water at 60° F. Table or

plot of weight/volume

for the range of

metering temperatures

expcted applicable to

the gravity of fuel

being burned.

(5) Higher heating value of

fuel from fuel analysis.

(6) Boiler feedwater

temperature to the

boiler.

17

(7) Air temperature to

forced draft fans or to

fuel oil burners.

(8) Fuel temperature to the

burners.

2.5.2.(d) Trial RePort. See

Section 6.0, Trial Data and Report● and Figure 26. Then select a data

sheet format appropriate to data..

rewired by paragraph 2.5.2. (c)

noting the boiler tested..’

2.6 SPECIAL CONSIDERATIONS FOR

DIESEL PROPULS ION PLANT TRIALS

This section addressee sea

trial related tests which are

peculiar to the diesel propulsion

plant and aplifies some areas which

are covered generally in paragraphs

2.2 through 2.4 above. A major

pur~se of the Economy and Endurance

trials is to provide base-line

OPrating data for the entire plantwhen using service fuel, and the sea

trials should be planned and carried

out with this in mind.

2.6.1 Auxiliarv Comwnents

The following are exmples of

auxiliary compnente which may be

part of a diesel plant:

.

(a)

(b)

(c)

Turbochargers,

reciprocating or gear

t~ blowers, or other

aourcee of cotiustion or

scavenging air pressure.

Engine-driven lube oL1,

fuel or cooling fluid

preps .

Independently driven

generators, pumps or

centrifuges.

(d) Power transmission

elements including

gears, couplings,

clutches, etc.

(e) Waste heat boilers

and/or auxiliary

boilers.

Special agreements should be

made prior to trials for observing

the performance of the auxiliary

component e mentioned above.

2.6.2 Revolutions

Sme as paragraph 2.2 except

for diesel installations having a

s1ip type COUP1 ing between the

engine and the shaft; then, both

engine revolutions and shaft

revolutions should be obtained.

2.6.3 Fuel Measurements

Sme as paragraph 2.2 except

as follows:

(a) The fuel consumption of

the main and auxiliary

engines and any other

fuel consuming e~ipent

in operation should be

meaaured separately.

(b) Syetema that return fuel

to the upstrem side of

the supply meter should

have the return measured

separately.

2.6.4 FueL Rate Data Rem ired

Sme as paragraph 2.2.

Include return fuel oil Meter

readings with other meter data. In

addition, fuel rate corrections forvariations of the following data

from design conditions should be

provided by the engine manufacturer:

(a) Inlet air temperature.

(b) Inlet air pressure.

18

(c) Inlet air moisture

content.

(d) Engine RPM.

(e) Exhaust pressure.

(f) Fuel oil heating value.

The purpose of these

corrections is to properly evaluate

diesel engine performance. Suitable

test devices should be provided on

trials to accurately measure these

variables.

2.6.5 W

When torsiometera are not

rewired to be fitted, brake

horsepower for diesel engines may be

estimated by the following methods:

(a) Rack Position - Brake

horsepower may be

closely approximated by

careful observations of

fuel injection rack

psitions and comparison

of these with data taken

during shop teets where

output is measured

directly on a water or

electric brake or

e~ivalent. For max imm

accuracy it is neceseary

that shop tests and

ship’s trials utilized

comparable fuel.

(b) S1 ip Coupling - On

installations using a

slip t~ coupling, the

torqe transmitted can

be closely approxtiated

by comparing the engine

RPM and shaft RPM with

slip data supplied by

the coupling

manufacturer.

the BHP may be computedwith very good results

for slow or intermediate

speed units. Engine

efficiency data, other

correlating data, or

s~ple correction curves

are also needed with the

indicator card data to

compute BHP. #

Each of the above methodB may

be used to determine brake

horse~wer. An agreed allowance forgear or coupling los Bes must be

applied to obtain shaft horsepower,if these elemente are in the power

train.

When a torsiometer is fitted,

the correlation between the SHP

detemined from the torsiometer and

the SHP determined from engine data

should be established during the

trials.

2.6.6 ShiD’s Overall Fuel Rate

If the diesel-powered ship has

separate fuel consuming auxiliaries,

such as auxiliary engines andjor

boilers, the fuel consumption for

these auxiliaries should be

detemined and corrected to etandird

conditions separately. If the main

diesel engine and the auxiliaries

use different fuels, consumption

should be separately corrected for

density and heat value. The ship’ s

overall fuel rate may then be

computed by suming the fuel

consumption of these elements and

the propulsion unit and dividing the “

sum by propulsion shaft horsepwer.

2.6.7 Trial Oata and Rewrt

See Section 6.0, Trial Oata

and Reprt and Figure 26.

(c) Indicator Cards -

Indicator cards or

eqivalent may be takenon each cylinder, and

19

2.7 SPECIAL CONS IDEATIONS FOR GAS

TURBINE PROPULSION PLANT TRIALS

This section covers sea trial

related items which are peculiar to

gaB turbine propulsion plants. This

guide is written around the basic

gas turbine propulsion unit

consisting of a gas generating

turbo-compressor and independent

free power turbine; however, it.. should not preclude trial

modifications which future gas

“turbine development may dictate.

2 .7.1 Auxiliarv Component S

The following are ex-pies of

auxiliary components which may be

part of the gas turbine plant:

(a)

(b)

(c)

(d)

(e)

(f)

(9)

PrecOOlers,

intercoolers, and after

coolers.

Reheaters, regenerators,

and recuperators.

Fuel conditioning

em i~ent.

Inde~ndent ly powered

generators and pumps.

Control e~i~ent and

safety devices.

Power transmission

elements including

gears, clutch, shaft

brake, coupling,

controllable pitch

pro-l ler, etc.

Waste heat or

independent ly fired

boilers.

SPC ial agreements should

made orior to sea trials for

observing

auxiliary

above.

the performance of the

be

2 .7.2 Fuel Rate Data Rew ired

Fuel rate corrections forvariations of the following from

design values should be provided by

the gas turbine engine manufacturer:

(a) Inlet air temperature.

(b) Inlet air moisture

content.

(c) Power turbine RPM.

(d) Inlet air pressure.

(e) Exhaust pressure.

These corrections are reqired

to properly evaluate gas turbine

performance. Suitable test devices

should be provided on trials to

provide the necessary data.

Barometric pressure and relative

humidity of the outside air should

be recorded to permit evaluation of

air inlet and exhaust duct systems.

However, the shipbuilder is

responsible for designing the air

inlet and exhaust systems to meet

design turbine inlet and exhaust

condition, and no correction to the

ship’s overall fuel rate should be

~mitted for excessive pressure

loss in these systems.

2.7.3 w

When tors iomet ers are not

fitted, brake horsepwer for gas

turbine engines may be estimated

from the engine RPM, internal gas

pressures and temperatures and for

fuel oil flow with sufficient

accuracy for endurance trial

pur~ses. Smple reference curves

and correction factors will be very

useful to develop estbatee.

When tors iometers are

rewired to be fitted, a correlation

should be established during trialscomponents mentioned

20

between the horsepower determined

from the torsiometer and the engine

brake horsepower as ascertained by

the engine pressure, RPM, and

temperature data.

2.7.4 ShiD Is Overall Fuel Rate

If the gas turbine powered

ship has separately operated fuel

consuming auxiliary components, such

as auxiliary engines and/or boilers,

then the fuel consumption for these

auxiliaries should be determined and

corrected to standard conditions

separately during trials. If the

gae turbine and auxiliaries use

different fuels, consumption data

should be separately adjusted for

density and heat ing value. The

ship’s overall fuel rate may then be

computed by suming the fuel

consumed by these units and the

propulsion unit and dividing the sum

by PrOeulsion shaft horsepower.

2 .7.5 Trial Data and Reprt

See Section 6.0, Trial Data

and Report and Figure 26.

2.8 SPECIAL CONSIDEWTIONS FOR

ELECTRIC DRI~ PROPULS ION PLANT

TRIALS

Electric drive propulsion as

covered in this section consists of

electrical power generating

e~ ipment and propulsion motor(s) .Drive units associated with the

electric propulsion generator and

motor units such am

stem turbine, gas turbine and

diesel engines are covered in

paragraphs shove and are not

re~ated in thie section.

2.8.1 Auxiliarv Comwnents

The following are exaples of

auxiliary com~nents which may be

part of the electric drive

propulsion plant.

(a) Heat exchanger units.

(b) Independently powered

pumps .

(c) Attached pumps.

(d) COntrOl e~ipment and

safety devices.

(e) Power transmission

elements including

gears, clutches, shaft

brakes, couplings,

controllable pitch ,

propeller, etc.

Special agreements should be

made prior to trials for observing

the performance of the auxiliary

components listed above.

2.a.2 w

Power output from the

propulsion motor can be determined

from the torsiometer when installed

or from the instruments if not

installed. Agreements should be

made prior to trials regarding

instrwentation to be used for power

determination during trials.

2.8.3 Trial Data and Rewrt

See Section 6.0, Trial Data

and Re~rt and Fi~re 26.

2.9 CENTRALI ZEO PROPULSION CONTROL

SYSTEM TEST

2.9.1 Purwse

The pur~se of the test is to

demonstrate the ability of the

system to control the propulsion

plant in all design modes and to

demonstrate eat iaf actory propu 1sion

plant resynse during transient

OpratiOn at spc ified rates andinitial and final conditions.

21

2.9.2 Procedure

Prior to sea trials the

control system and its subsystems,

seneing elements, valve and

evipment operators, safety devices,alarms and indicators should have

been tested for proper installation

and operation and should have been

adjusted and timed to the values

predicted to provide smooth and

correct control of the ship at sea.

Cremen responsible for operationi should be fully trained in the

capabilities and operation of the

control system prior to sea trials.

Satisfactory integrated operation of

the total control system should also

have been demonstrated to the extent

practicable.

At the beginning of sea trials

it is advisable to teat the control

system at reduced powers and make

the indicated adjustments prior to

demonstration of the full

re~irements. All rewired

OFratiOnS of the controls shOuld be

demonstrated under free route,

maneuvering and emergency conditions

in accordance with the sea trial

agenda agreed to in advance.

In addition to proper control

in each mode, satisfactory

transition between modes of control

should be demonstrated. When the

bridge control is demonstrated,

there should be no assistance from

the engine room watch, and when

centralized engine room control is

demonstrated there should be no

assistance from local e~ipment

watchstanders unless such manual

participation ie incorporated in the

design.

Safety features should be

demonstrated at sea, if possible,

without disrupting the adjustment of

the control system or setting up

conditions beyond the operating

range of the propulsion system.

2.9.3 Trial ReWrt

See Section 6.0, Trial Data

and Reprt and Figure 20.

.

22

SNAMS GUIDE FOR SEA TRIALS

Ahead Astern Boiler

TRIAL Endurance Endurance Economy Steam Rate Overload

OURATION 4 Hoursn 30 Minutes 4 Hoursa 1 Hour 1 Hour

MWR LEVEL Max Des igna Max Continuous Servicea As obtained As required

from nozzle to load

setting boiler

CRITICAL Power Tor~e/RPM Power Level & Power & Steam Fuel Consump””

MEASUREMENTS Fuel Coneump Flow

DATA INTERVAL FOR

CRITICAL MEASURE~NTS 15 Minutes 10 Minutee 15 Minutes 10 Minutes 15 Minutes

TorWe Torpe S-e ae Ahd Endur Torque Fuel F1OW

RPM RPM plus : RPM FO Temp

Ste- Press Ste- Prees Fuel Steam Press Steam Press

SUPPORTING DATA Stem Temp Stem Temp Aux Load Steam Temp Steam Temp

(as prtinent ) Prop Pitch Prop Pitch PRPLS Motor KW Stack Temp

PRPLS MOtOr KW PRPLS Motor KW Combustion Vacuum Air Press

Vacuum Vacuum Air Temps Exh Temp

E Exh Temp Exh Press Cond Flow

DEVIATION OF CRITICAL Plus Mfq” 6 Lim Plue Mfr, s Lim Plus 5% Plus 5% ‘“

HEASUREMSNT AVERAGES Minus 2% Minus 10% Minus 50 See Text Minus O%

FROM LEVEL SPECIFIED

FLUCTUATION OF INOI- PIUS 5a PIUB Mfr Os Lim Plus 50 Plus 50

VIDUAL DATA ITEM FROM Minus 5% Minus 2Da Minus 50 See Text Minus 5%

AVERAGE FOR CRITICAL

~AsuREMNT

PLANT CONTROL Power or RPM Torpe, RPM or Power or RPM POwe r Fuel Flow

PAWTER Chest Prees

~ANS OF CONTROL Ahead Throttle Astern Throttle Nozzles Nozzles Boiler

Controls

a Endurance and Economy Trials may be concurrent if pwer level is the same.

If rower levels differ, the duration of the Endurance Trial mav be reduced to two hours if it fol lows the Economy

Trial immediately (alternatively recommended) .

FIG. la. RECO~ENOATIONS FOR STEAM PROPULS ION PLANT TRIALS

.,

,,

sN~ GUIDE FOR SEA TRIALS

.

. . ,

TRIAL Ahead Astern Economy

Endurance Endurance

DURATION 4 Hoursn 30 Minutes 4 Hoursa

POWER LEVEL Max Continuous Max Astern Cent inuous Cent inuous

Rat ing Rat ingn Service Heating

CRITICAL Power Tor~e/RPM Power Level &

MEASUREMENTS Fuel ConSump

INTERVAL FOR 15 Minutes 10 Minutes 15 Minutes

CRITICAL MEASUREMENTSToraue Toraue Sae as Ahd Endur

SUPPORTING DATA RPM - RPM plus : Aux Load

(ae ~rtinent ) Prop Pitch Prop Pitch Fue 1

PRPLS Motor KW PRPLS Motor KW

Rack Position Rack Position

Max Cylinder Firing FO Ht Content

Preesure Air Intake Temps

PLANT CONTROL P~TER Power or RPM TOr~e RPM Power Or RPM

a Endurance and Economy Trials may be concurrent if Fwer level is the sine.

If rower levels differ. the duration of the Endurance Trial mav be reduced to two hours if it follows

bthe Economv Trial immediately (alternatively recommended) .

To be in accordance with Classification Society requirements.

FIG. lb. RECOMMENDATIONS FOR OIESEL PROPULS ION PLANT TRIALS

SNWE GUIDE FOR SEA TRIALS

TRIAL Ahead Astern Economy

Endurance Endurance

DURATION 4 Hoursa 30 Minutes 4 Hoursa

PONER LEVEL Max Oesigna Max Continuous Service”

CRITICAL Power Torque/RPM Power Leve 1 &

MEASUREMENTS Fuel ConSump

INTERVAL FOR 15 Minutes 10 Minutes 15 Minutes

CRITICAL MEASUREMENTS

TorWe Torque Same as Ahd Endur

SUPPORTING OATA RPM RPM plus: Aux Load

(as prtinent ) Prop Pitch Prop Pitch Fuel

PRPLS Motor KW PRPLS Motor KW

Exh Temp Exh Press

Air Intake Temps

DEVIATION OF CRITICAL Plus Mfg, s Lim Plus Mfr)s Lim Plus 5%

MEASUREWENT AVBRAGES Minus 2% Minus 10% Minus 5%

FROM LEVEL SPECIFIED

LNn FLUCTUATION OF

INDIVIDUAL DATA ITEM Plus 5% Plus Mfr, s Lim Plus 5%

FROM AVERAGE FOR Minus 59 Minus 20% Minus 5%CRITICAL ~ASURS~NT

PLANT CONTROL PARAWETER Power or RPM Torque RPM Power or RPM

MEANS OF CONTROL Ahead of Throttle Astern Throttle Ahead Throttle

a Endurance and Economy Trials may be concurrent if power level ie the same.

If rower levels differ, the duration of the Endurance Trial may be reduced to two hours if it follows

the Economyb

Trial immediately (alternatively recommended ).

To be in accordance with Claesif ication Society requirements.

FIG . 1.C RECOWNDATIONS FOR GAS TURBINE PROPULS ION PLANT TRIALS

,,. . ,

. .

-,

Nm

Dev iat ion

of Average

From DeSian

Inlet Stem Pre SSure - % ~3

Inlet Stea Temperature - ‘F ~ 25

Exhaust Pre8eure - In. Hg. fia. ~ 0.5

Shaft RPM - 8 + 10

-5

Shaft Horse~wer - 0 ~5

Stem (Condensate) Flow - Gal. ---

Fluctuation

of Reading

From Averaae

+2

Data

Interval

10

10

10

10

10

---

FIG. 2. ACCEPTABLE OEVIATION AND FLUCTUATION TOLE~NCE AND RBAO ING INTERVALS

FOR STEM RATE TEST OATA

3.0 WE~RING AND SPECI~ TESTS

3.1 SELECTION OF TESTS

This section contains

procedures for conducting

maneuvering and other special trials

and tests. Ship’s specifications

should include the owner’s selection

from the following tests:

3.4

3.5

3.6

3.7

3.8

3.9

3.10

3.11

3.12

3.13

3.14

3.15

3.16

3.17

3.18

3.19

3.20

3.21

3.22

3.23

Ahead Steering

Astern Steering

Auxiliary Means of Steering

Turning Circlee

,,2,,Maneuver

Initial Turning

Pullout

Direct Spiral

Reverse Spiral

Thruster

Quick Reversal from Ahead to

Astern

Quick Reversal from Astern to

Ahead

Low Speed Controllability

Maneuvers

Slow Steming Ability

Anchor Windlass

Distilling Plant

Miscellaneous Auxiliary

Syetems

Emergency Propul Sion SySteM8

Navigation E~i~ent

Dyn-ic Positioning System

In selecting tests,

cons iderat ion should be given to

their pur~se. Some are intended to

demonstrate ~rfomance of vital

machinery and sat isfy re~latory

re~iremente. Some are easent ial to

verify that the vessel has

satisfactory basic course keeping

and turning ~alities while others

are intended to obtain maneuvering

data to be used in establishing

operating regulations or providing

data for future designs. The

subse~ent utility of the data

should be the basis for selection.

When possible, tests should be

conducted to compare the ship, B

actual maneuvering performance with

the designer’ s estimation.

Maneuvering trials, paragraphs 3.7

through 3.13, provide data which is

applicable to all ships of a class,unless there has been a change in

draft, rudder or underwater

appendages. In view of the

increased size of tankers and other

bulk carriers and the conse~ent

greater disparity between their

momentum and the forces available to

change it, together with the

~tential for catastrophic ~llution

in the event of collision or

grounding, owners should consider

specifying maneuvering tests at

other than the speeds and conditions

than prescribed herein. The

objective should be to explore the

maneuvering characteristics of each

new class of ship so as to be able

to provide the bridge with data

aPPlic*le to all situations liableto be encountered.

The test sped as used in

these yidelines is defined as the

sped at which a ship may be

expcted to navigate in areas where

maneuvers are nomal ly rewired, and

are not restricted by insufficient

water depth or channel boundaries.

In the case of slow, full form

ships this sped may be close to

design sea sped. On the other hand

for fast, fine fom ships it may be

27

a much lower proportion of design

speed. The following formula is

suggested as a guide to selecting

test epeed:

VT= CBXVD

where: VT = test speed

‘D= design speed

CB= block coefficient at

the design draught

This formula provides test

speed values for bulk carriers and

dry cargo/container ship types which

are often used in general practice.

Unless otherwise indicated tests

should be comenced at the test

speed.

3.2 PREPARATION

PrOpr preparation is

essential to obtain meaningful data

and avoid abort ing mandatory test e.

Detailed instruction for performing

each test, including maneuvering

diagrms and data sheets where

pert inent, should be prepared in

advance. Test conductors and data

takers ehould be instructed in their

duties, shown their station, checked

out on instruments and have their

understanding of the test verified.

3.3 REPORTS

Reports should present the

data in t~ular or diagr-atic

fem. Smple diagrma and data

sheets are shown in Section 6.

Reprts should include, where

pertinent, discussion of the

significance of findings and an

explanation of data anomalies.

Re~rted information should be of

sufficient detail to provide the

data rewired to prepare the Pilot

Card, Wheelhouse Poster, and

maneuvering Booklet described in IMO

Resolution A. 601 and the first order

steering ~ality indices K and T.

3.4 AHEAO STEERING

With the ship in the trial

ballast condition and proceeding

ahead at maximum trial shaft RPM,

move the rudder at maximum rate as

follows:

Midships to Hardover Right -

Hold ten seconds.

Hardover Right to HardOver

Left - Hold ten seconds.

Hardover Left to HardOver

Right - Hold ten seconds. ,

HardOver Right to Midships -

Maneuver complete.

After ship- s speed has been

reetored, use the other steering

power unit and repeat the above

rudder movements in opposite

sequence. For rudder movement rate,

use the average degrees per second

for total time from start to 5

degrees before ordered angle.

Throttle setting for single screw

ships should not be changed during

test. For multi-screw ships, the

throttle may be adjusted as

necessary to correct unacceptable

ovarsped or overtor~e.

The following data should be

recorded on Figure 5 during the

test:

(a)

(b)

(c)

(d)

(e)

(f)

Time of test and base course.

Time re~ired for each rudder

movement.

Maxtium rudder anglee.

Maximum oil pressure on rm.

Servo pressure, replenishing

pressure and pump stroke at

maxtium demand, if avail tile

from shiv’s instruments and

indicators.

Power unit in use and

volts, aps and RPM.

idle

28

(9)

(h)

(i)

(])

(k)

Steering gear motor minimum

and maximum volts, mperes,

and RPM for each rudder

movement.

Propeller shaft RPM at start

and finish of test on each

unit.

Depth of water, sea condition,

and wind direction.

Steering station in control.

Trial drafts, fore and aft.

The above test is appropriate

for dual power unit electro-

hydraulic systems. If a different

system is installed, suitable

adjustments to the re~irements

should be made.

3.5 ASTERN STEERING

With the ship in the trial

ballast condition and moving astern

at maximum astern shaft e~ed, using

either one of the main power units,

move the rudder at maximum rate as

follows:

Midships to Hardover Right -

Hold tan aeconde.

HardOver Right to HardOver

Left - Hold ten seconds.

HardOver Left to HardOver

Right - Hold ten seconds.

HardOver Right to Midships -

Maneuver complete.

Record data as prescribed in

paragraph 3.4 dove.

3.6 AUXILIARY ~ANS OF STEERING

Where auxiliary pwer steering

means is specified to control the

rudder at reduced ship’s sped,

rate, and range of rudder movement,

euch opration should be

demonstrated at sea. In addition to

shaft RPM and the of rudder

movements, the time necessary tosecure normal mode and activate the

auxiliary unit should be recorded.

When the standby unit of a dual

hydraulic steering gear is the

specified auxiliary means of

steering, it is tested under

paragraph 3.4, and the test need not

be re~ated.

3.7 TURNING CIRCLES

Turning circles should be

performed to both starboard and

with 35 degrees rudder angle or

maximum design rudder angle

permissible at the test speed.

The essential information

be obtained from this maneuver

consists of tactical diaeter,

advance and transfer. Also of

port

the

to

interest are the final ship speed

and yaw rate in the “steady state”

of the turning circle. A turning

circle of at least 54o degrees

should be completed to determine the

main parmeters of the maneuver and

allow correction for any drift

caused by a steady current or wind.

With the ship in the trial

ballast condition and proceeding

ahead at the maximum trial shaft

RPM, with either steering power

unit, move the rudder at maximum

rate and ~rform the following

maneuvers:

Move rudder to HardOver Right

and hold until ship’s heading has

changed 540 degrees.

Resme a straight course andrestore sped.

Move Rudder to Hardover Left

and hold until ship’ s heading has

changed 540 degrees.

Resume a straight course.

Throttle setting for single-

screw ships should not be changed

29

during the test. For multi-screw

ships, throttle may be adjusted as

necessary to correct unacceptable

overspeed or overtor~e. If

throttle adjustment has to be made

during the turn, the maneuver ehould

be repeated at a reduced approach

RPM to determine the maximum speed

at which a hard turn can be made

without throttle adjustment.

The following data should be

recorded or derived:

(a)

(b)

(c)

(d)

(e)

Time of teet, and base course.

Rudder angle.

compass reading to nearest

degree every 10 seconds that

ship is in the turning

maneuver.

Time elapsed, and advance from

start of rudder movement and

clearing base course if

radiometric data is

available. To detemine

advance-to-c lear-base-course

and time-to-clear-base-course,

plot ship’s heading at each

~sition determination pint

using a line scaled to ship’s

length to indicate ship’ s

heading. The 1ine

representing the ship should

cross the track line at the

pint corres~nding to the

location of the receiving

antenna for the radiometric

device. The pint at which

the stern end of the line

representing the ship clears

the line of the base course

should be indicated, and the

advance to this pint scaled

from the plot. Corresponding

time can be detemined from aplot of time against heading.

Ship’ s psition at suitable

intervala from radiometric

eqipent, if installed. If

(f)

(9)

(h)

(i)

radiometric e~ipment is not

installed, ship, s track shouldbe obtained by radar, shore

station tracking, or visual

observation of the wake.

Observation intervals should

coincide with heading data

intervals.

Shaft RPM at beginning and end

of each circle.

Depth of water and sea

condition.

Wind direction and velocity.

Trial draft fore and aft.

Circle tests may be specifiedat depths, drafts, speeds, and

rudder angles other than those

given, if ship’ s maneuvering

characteristics re~ire further

exploration.

At the completion of each of

the turning circle tests a pullout

test may be prfomed to provide

information on the ship’ e dynaic

stability. For further information

see paragraph 3.10.

Turning circlee should be

plotted and tactical dimensions

re~rted as illustrated in Section

6. See Fi~re 6 and Ap~ndix A to

Chapter 6 when precise tracking isavailable. See Figure 7 when

precise tracking is not available.

●The “Z” Maneuver may be

identified as the zig-zag Maneuver

or the Kempf Maneuver.

With the ship in trial ballast

condition and proceeding ahead into

the wind at the maxtim trial shaft

RPM, with either steering pwer

unit, move the rudder at maximum

rate and ~rfom the following

maneuvers:

30

Move the rudder from center to

10 degrees right - hold until ship’ s

heading is 10 degrees to the right

of the original course.

Move the rudder from 10

degrees right to 10 degrees left -

hold until ship’s heading is 10

degrees to the left of the original

course.

Move the rudder from 10

degrees left to 10 degrees right -

hold until the ship’ s heading is 10

degrees to the right of the original

course.

Move the rudder from 10

degrees right to 10 degrees left -

hold until original heading is

restored. Steady on original

course.

In some cases it may be

desirable to modify the test so as

to include a fifth rudder movement

in order to collect additional data

for other analysis. A pullout test

may aleo be performed u~n

completion of the “Z” Maneuver.

The standard type “Z”

ManeuverS are the 10”/10°; which is

10° rudder change, 10° change of

heading at next rudder execute; and

20”/20” tests.

At least one standard typ “Z”

Maneuver should be ~rfomed at the

test speed. The 10”/10° test is

preferred, as it provides btter

discrimination between ship

characteristics. The 20°/200 test

should also be included to provide a

comparison with data availsble from

earlier tests. For stiilar rea80ns

of comparison the 20”/10° test may

be taken into cons iderat ion. The

20”/10° tests are fre~ently

perfomed in long towing basins, in

narrow waters, and for reasons of

special analysis.

The essential information tobe obtained for the ,~Z,,Maneuver is

the initial turning time, time to

second execute, the time to checkyaw, and the angle of overshoot. In

addition an analysis of the “Z,,

Maneuver furnishes values of the

steering indices K (gain constant )

and T (time constant) associated

with linearized steering theory.

See “Analysis of Kempf ‘s Standard

Maneuver and Proposed Steer ing

Quality Indices” , First Smposium on

Shin Maneuverability, David Taylor

Model Basin Report 146, 1960 by K.

Nomoto.

The following data should be

recorded or derived:

(a)

(b)

(c)

(d)

(e)

(f)

(9)

(h)

(i.)

Time of test and base course.

Time of shift rudder, start

and etop of actual rudder

mot ion.

Time rudder is held at each

position.

Compass reading to the nearest

degree every 10 seconds that

the ship is in the “Z”

Maneuver.

Shaft RPM at beginning and end

of test.

Wind velocity and direction.

Oepth of water and sea

condition.

Trial drafts, fore and aft.

Ship’s track from radiometric

data, if e~ipment is

installed.

31

Prepare a plot of rudder

posit ion and ship, s heading changes

during the maneuver. Indicate the

tactical dimensions as illustrated

in Section 6, specifically Figure 8.

Tests may be specified at

different ship speeds, depths of

water, ballast conditions, and

rudder angles if more data is

rewired.

3.9 INITIAL TU~ING TESTS

The initial turning te5t S

provide information on the transient

heading condition between steady

state approach and change of heading

after application of the rudder.

These tests should be performed with

rudder angles of 10 degrees and 20

degrees. The time history of

heading and yaw rate should be

plotted. These tests may be

performed in conjunction with

turning circle tests and partially

with “Z“ Maneuvers, which aredescribed in Sectione 3.7 and 3.8,

res~ctively.

With the ship in the s~cified

trial conditions and proceeding

ahead at the designated speed and on

a steady course, conduct the

maneuver as follows for two separate

tests, one at a rudder angle of 10

degrees and one at a rudder angle of

20 degrees.

Lay the rudder over to the

specified setting and hold until the

turning becmes steady.

The following data should be

recorded on Fi~re 9.

(a) Before starting the test:

(1) Time of teat and base

course.

(2) Ship aped and

corres~nding RPM.

(3) Wind velocity and

direction.

(4) Depth of water and sea

condition.

(5) Trial draft.

(b) During the test:

(1) Rudder angle.

(2) Gyro compass reading

every 10 seconds to the

smallest fraction of

degree readable.

Both heading and rate of

change of headings should be plotted

for each rudder position.

3.10 PULLOUT TESTS

The pullout test gives a

simple indication of a ship, s

dynaic stability on a straight

course. The ship is first made to

turn with a certain rate of turn in

either direction, upon which the

rudder is returned to midship. If

the ship is stable, then the rate of

turn will decay to zero for turns to

both ~rt and starboard. If the ship

is unstable, then the rate of turn

will reduce to some residual rate of

turn. The pullout tests must be

per fomed to both ~rt and starboard

to chow ~esible ae~etry.

Normally, pullout teats are

~rfomed at the end of the turning

circle tests, “Z“ Maneuver, and

initial turning tests, but they may

be carried out separately.

Each test consists of a prt

and starboard run as follows:

Attain a eteady turning rate

with a fixed rudder angle of

approximately 15 degrees to 35degrees. The engine control

settings are kept constant.

Return rudder to midship’s

psition, and record time.

32

Record heading, ship speed,

and pro~ller RPM at 10 second

intervals. These recordings

should be continued for 12

readings, i.e. , 120 seconds,

past the interval in which

steady state, i.e. , a constant

rate of turn, is obtained.

The results should be reported

as shown on Figure 10.

.3.11 THE DI~CT SPI= TEST

The direct spiral test is an

orderly se~ence of turning circle

tests to obtain a steady turning

rate versue rudder angle relation.

In case there are reasons to

expect the ship to be dyntiically

unstable, or only marginally stable,

a direct spiral test will give

additional information. This is a

time consuming test to perfom,

especially for large and slow ships.

The test is very sensitive to

weather conditions. Also a

significant mount of time and care

is needed for the ship to obtain a

steady rate of change of heading

after each rudder angle change.

Ship’s s~eds most unfavorable

to directional stability at trial

draft should be esttiated and

s~cified for the test. Since this

test may be adversely affected by

the elements, it should be conducted

only in relatively calm seas, i.e. ,

sea state 3 or less, and winds of

less than 10 hots.

With the ship in the spcified

trial ballast condition and

proceeding ahead at the designated

sped and on a steady course, u~ingeither steering ~wer unit, conduct

the maneuver ae follows:

Lay the rudder 20 degrees to

starboard and hold until

the turning rate becomes

steady.

Move the rudder to the

following setting and hold

at each setting until a

steady turning rate* in

degrees is obtained: 20R,

15R, 10R, 5R, 3R, 1X, O,

lL, 3L, 5L, 10L, 15L, 20L,

15L, 10L, 5L, 3L, IL, O,

lR, 3R, 5R, 10R, 15R, 20R.

●A eteady turning rate is the

difference between succeaeive ship

headings and should be noted as the

test progresses. When these

differences are reasonably constant

for at lea8t six consecutive

readings, the rudder is ordered to

the next setting.

The following data should be

recorded:

(a) Before starting the test:

(1) Time of test and base

course.

(2) Ship awed and

corres~nding RPM.

(3) Wind velocity and

direction.

(4) Depth of water and sea

condition.

(5) Trial draft.

(b) During the test:

(1) Rudder angle.

(2) Gyro Compase reading

every 10 seconds to the

8mallemt fraction of

degree readable.

Rate of change of headings

should be plotted for each rudder

@sition.

In cases where the ship is

dynamically unstable it will appear

that it is still turning stead:ly in

the original direction although the

rudder is now 81 ight ly deflected to

the oppsite eide. At a certain

stage the yaw rate will abruptly

33

change to the other side and the yaw

rate versus rudder angle relation

will not be defined by a separate

curve. Upon completion of the test

the results will display the

‘-hysteresis loop” . See Figure

n(b) , Unstable Ship.

3.12 THE REVERSE SPI~ TEST

The reverse spiral test may

provide a more rapid procedure than

the direct spiral test to define the

instability loop as well as the

unstable branch of the yaw rate

versus rudder angle relationship.

In the reverse spiral test the

ship is steered at a constant rate

of turn and the mean rudder angle

rewired to produce this yaw rate is

measured.

The necessary e~ipment is a

properly calibrated rate of the turn

indicator and an accurate rudder

angle indicator. Accuracy can be

improved if a continuous recording

of the rate of turn and the rudder

angle are available for analysis.

In certain cases the test may be

performed with the automatic

steering devices available onboard.

Prior to the conduct of the test,

the rate of turn indicator

calibration may be checked by timing

turns using the gyrocompass.

If manual steering is ueed,

the instantaneous rate of turn

should be visually displayed to the

helmsman, either on a recorder or on

a rate of turn indicator.

Points on the curve of yaw

rate versus rudder angle may be

recorded in any order using the

reverse spiral test techni~e.

The procedure for obtaining a

pint of the curve should be ae

follows:

The ship is made to approach

the desired rate Of turn, by

apelyin9 a moderate rudderangle. As soon as the desired

rate of turn is obtained, the

rudder is actuated such as to

maintain this rate of turn as

precisely as possible, using

progressively decreasing

rudder motions until steady

values of epeed and rate of

turn have been obtained.

Steady rate of turn should

usually be obtained fairly *

rapidly since rate-steering is

easier to perform than normal

compass steering.

The test should be performed

at the following steady rates

of turn in degrees per second:

I.OR, 0.8R, 0.6R, 0.4R, 0.2R,

O.lR, O, O.lL, 0.2L, 0.4L,

0.6L, 0.8L, l.oL.

The following data should be

recorded:

(a) Before starting the test:

(1) Time of test and base

course

(2) Ship sped and

corresponding RPM

(3) Wind velocity and

direction

(4) Depth of water and eea

condition

(5) Trial drafts

(b) The average rudder angle

associated with each

associated steady state turn

rate measurement pint.

This procedure should be

repated for a range of yaw rates

until a complete yaw rate versus

rudder angle relationship is

established, e.g. , between 20

degrees ~rt to 20 degrees starboard

rudders.

34

The results of the spiral

teste should be presented in

accordance with the diagras

provided in Figure 12. h pronounced

“S” shape on Figure 12 illustrates a

ship with instability, and this

instability provides a hysteresis

loop like that illustrated in Fiwre

n(b) , Unstable Ship, for the rate

of change of heading.

3.13 THRUSTER TESTS

i3: 13.1 Bow Thruster Tests

In addition to the performance

test data of flow thrusters obtained

during dock trials, tests of bow

thrusters at sea demonstrate

thruster effectiveness in turning

the chip.

With the ship in trial

ballast condition, conduct the

maneuvers below. It ehould be noted

that reduced thrust may result

unless submergence of the thruster

axis of at least 0.S times the

thruster dimeter is provided.

Bow thruster tests for dry

cargo ships in the trial ballast

condition are severely influenced by

sea and wind and Bhould be conducted

only in protected areaa or in the

o~n sea when sea conditions areexceptionally smooth.

With the ship dead-in-water

and heading into the wind, o~rate

the bow thruster at full thruet for

10 minutes’ or the the it takes to

change the ship’s heading 30 degrees

to left of the original heading,

whichever occurs firet. Reverse the

bow thruster and re~at.

The following data should be

recorded on Figure 13 during the

test:

(2) Compass readings to

nearest degree every 10

seconds

(3) Depth of water and sea

condition

(4) Wind speed and direction

(5) Trial drafts

3.13.2 Other Thrust Devices

Other thrust devices such as

stern thrusters and active rudder~may be tested similarly to the

descriptions in paragraph 3.13.1.

The data sheets provided in Section

6, Figure 13 are suitable.

3.13.3 special Thruster Tests

For tankerB or other similarly

configured ships where deep trial

drafts are ~sBible, additional

spcial tests may be conducted to

better define the effectiveness of

thKuBterS when the Bhip haB forward

mot ion.

The following tests may be

conducted and data ehould be

recorded:

(1) Ship moving ahead at

shaft RPM corresponding

to 3 hots:

(a) With the ship

moving into the

wind, use the

thruster and full

rudder to change

the ship’ e heading

30 degrees to the

left of the

original heading.

(b) Use the thruster

and full rudder to

swing the ship

(1) Time of test and base

course

35

from left 30

degrees to the

right of the

original heading.

(c) Repeat (1) (a) and

(b) above, using

full rudder

without the

thruster.

(2) Ship moving ahead at

shaft RPM corresponding

to 6 knots:

Re~at maneuvers in (1)

(a ) through (c ) above.

(3) Ship speeds above 6

knots:

Repeat maneuvers (1 ) (a)

through (c ) above in

increments of 3 knots

above 6 knots unt i1 the

thruster is no longer

effective.

3.14 QUICK RSWRS~ FROM WEAO TO

ASTERN (STOPPING TESTS)

With the ship at trial drafts

and proceeding ahead at maxtium

trial shaft RPM and nomal machinery

0Fratin9 condition, signal “FU1lAstern” while maintaining the rudder

in the -idship’s position. Reverse

the throttle at m=imum allowable

rate or move the automatic control

lever in one motion to the full

astern ~sition. See paragraph 2.9

for the centralized control test.

When the ship gains sternway,

continue with the scheduled tests.

The following data should be

recorded on data sheets like Fi~re

14 during the test:

(a) Time of test and base course.

(b) Prime mover parmeters

immediately prior to “Full

Astern” signal.

(c)

(d)

(e)

(f)

(9)

(h)

(i)

(])

(k)

(1)

(m)

RPM, tor~e, and significant

prime mover par-eters at

freqent intervals during the

maneuver.

Time of issuing aster” order.

Time when propeller stops

prior to reversal.

Time shaft starte astern or

the propeller pitch is

positioned for astern way.

Time to stop ship “Dead-

in-Water” .

Time to reach re~ired maximum

astern shaft RPM.

Ship-s position at suitable

intervals from radiometric

ewi~ent, if installed, sothat a diagrm of the reversal

maneuver showing track and

heading may be plotted. If

radiometric e~ipment is not

installed, take Dutch log

data.

Nutier of markers dropped and

time and distance interval

with corresponding ahead

reach, when Outch log method

io ueed.

Oepth of water and sea

condition.

Wind direction and velocity.

Ship’s drafte.

For the pur~se of obtaining

o~rat ing data, additional etoppingtests may be conducted from other

initial speds and using other

stopping aids such as rudder

cycling, as agreed.

36

3.15 QUICK RS~RSAL FROM ASTERN TO

AWEAD

With the ship in the trial

ballast condition and moving asternat maximum specified RPM, signal

‘-Full Ahead” while maintaining

rudder in the aidship’ s position.

Reverse throttle at maximum

allowable rate. When the ship has

gained headway, continue with

scheduled tests..

The following data should be

recorded during the test: (See

Figure 14 for data sheets. )

(a)

(b)

(c)

(d)

(e)

(f)

(9)

(h)

Time of test and base course.

Prime mover paraeters

immediately prior to “Full

Ahead’, signal. Monitor

maximum excursions of RPM and

tor~e, if available, during

the maneuver.

Time shaft starts ahead.

Time to stop ship

“Dead- in-Water. ”

Ship, s ~sition at suitable

intervals from radiometric

e~i~ent, if installed, so

that a diagrm of the reversal

maneuver may be plotted.

Time tO come to ful 1 aheadshaft RPM.

Depth of water and sea

condition.

Wind direction and velocity.

NOTE: Attempts to detemine

stern reach from Dutch

Log Oata is not advised

due to the erratic track

of the ship when going

astern and the effects

of the pro~ller wash.

3.16 LOW SPEED CONTROLLABILITY

MANEWRS

NOTE : When scheduling this

maneuver for a stem

plant, avoid placing it

immediately after the

astern endurance run, to

reduce the severity of

thermal shock.

With the ship in the trial

ballast condition and proceeding

into the wind on a steady course at

6 knots ahead, conduct the following

maneuvers:

(a)

(b)

(c)

(d)

(e)

(f)

(9)

(h)

Lay the rudder to 10 degrees R

and hold for 30 seconds.

Move the rudder to 10 degrees

L and hold for 30 seconds.

Move the rudder to O degrees

and hold for 30 seconds.

Return to the base course and

adjust eped to 6 knots with

rudder at O.

Lay the rudder to 35 degrees R

and hold for 30 seconds.

Move the rudder to 35 degrees

L and hold for 30 seconds.

Move the rudder to O degrees

and hold for 30 seconds.

Return to base course and

adjust to next sped.

Repat the maneuver with speed

decreased at 1 knot intervals until

the s~ed at which the ship does not

res~nd to the helm is detemined.

The following data should be

recorded on Figure 15:

(a) Before starting the test:

(1) Time of test and base

course.

37

(2) Ship speed and

corresponding RPM.

(3) Wind velocity and

direction.

(4) Depth of water and sea

condition.

(5) Trial draft, fore and

aft.

(b) During test:

(1) Time to shift rudder,

i.e. , start and stop of

actual rudder motion.

(2) Time rudder is held at

each position.

(3) Max imum heading change

from base course.

3.17 SLOW STEWING ABILITY

The ability to proceed at

steady slow swed can be determined

from the ship’ s speed associated

with the lowest ~ssible engine

revolutions per minute in calm

weather conditions. This is only

intended to address engine

conditions and not steering control.

See Figure 16 for a data sheet.

3.18 ANCHOR wINDLASS

A maximum limit to the depth

of water in which the test may be

conducted should be h~aed in the

interest of safety. If the ability

of the bandbrake to stop the runout

of the anchor and chain was a

certainty there, then would be no

need for this test. If the test is

conducted with the ship in a depth

of water which exceeds the length of

the anchor chain, then the

conse~ences of handbrake failure is

pullout of the chain bitter end with

the attendant dmage to the ship and

a hazard to personnel.

(a) Test procedure for forward

windlass:

(1) Lower one anchor to just

below the waters edge

under control of the

windlass.

NOTE 1, If specified or if

rewired by

regulatory bodies

to demonstrate the

ability to drop

from the hawse

pipe under control

of the handbrake,

and sea conditions

permit it, this

step may be

omitted.

NOTE 2. If sea conditions

are such that

there is a risk of

contact between

the anchor and the

bow of the ship,

unlock the wildcat

and drop the

anchor from the

stowed position

stopping on the

brake just below

the hawse pipe and

locking-in before

proceeding with

step (l).

(2)

(3)

(4)

Set handbrake and

disengage wildcat.

Lower the anchor under

control of the handbrake

stopping approximately

every 15 fathoms unt i1

design handbrake

requirements are met.

Repat steps (l), (2),

and (3 ) with other

anchor.

3s

(5)

(6)

(7)

(8)

(9)

(lo)

Lock-in one anchor and

hoist at maximum design

speed to 5 fathoms

above the Pint where

the design re~irement

for simultaneously

hoisting both anchors

begins. Place this

anchor on the handbrake.

Repeat step (5) fOr

other anchor, except

leave wildcat engaged.

Lock-In first anchor

hoisted and while

lowering both anchors

simultaneously at

maximum speed, push

stop-button to interrupt

power and observe

ability of motor brake

to stop and hold the

windlaes.

NOTE : This step does

not apply to

stem windlasses.

Restore power and adjust

to maximum dual hoist

paition.

Hoist both anchors

simultaneously to just

below the waters edge at

maximum design sped.

House anchora

individually and secure.

(b) Data to be recorded:

(1) Chain sped.

(2) Windlaee motor volts and

m~res or etea supplyand exhauet preseurea.

(3) Length of chain in water

at brake stops, and

verification that anchor

did not bottom.

(4) Any unusual occurrence.

See Figure 17 for a datasheet.

(c) Test procedures for sternwindlass:

The installation test outlined

in Section 4 .24.2 of Technical

and Research Bulletin 3-39,

“Guide for Shop and

Installation Tests-1985, “

should suffice for test of the

etern windlaee.

3.19 DISTILLING PLANT

The distilling plant should be

operated with sea water feed to

demonstrate the specified

capacities. Operation in

conjunction with propulsion trials

should be ae rewired by the ship’s

specifications. The ability of the

distilling plant to produce the

max bum want ity and rewired

~ality distillate for a period of

not less than six hours should be

demonstrated in its normal underway

mode of o~ration. See Figure 18

for a data sheet.

3.20 MISCELLANEOUS AUXILIARY

SYSTEMS

Dockside conditions are oftennot suited for testing certain

habitability and other auxiliary

systems. When sea trial conditions

are neceaeary or more favorable,

these systms should be operated at

sea aa spcified or agreed and

sufficient data taken or

observations made to determine that

the opration ia satisfactory or to

identify problems. The following

eWiWent, systems and surveys oftenare in this category:

Airborne Noise Survey

Refrigeration E~i~ent

Galley E~ipant

39

Air Conditioning System

Water Treatment Systems

Auxiliary Propulsion Unit

Ventilation and Heating System

Ventilation Draft Survey

Tank Cleaning system

Countermeasures Washdown

Ballasting and Deballasting

Systems

Fog Fom System

Smoke Abatement System

Sewage Dispoeal System

Photometric Survey

Communication E~ipment

Elevators and Dutiwaiters

Stabilization Systems

Hull Vibration

Machinery Vibration

Automatic Pilot

Provision of greater than

natural loads or operation of

e~iPMent9 under abnormal conditionsshould not be rewired. An example

is operating the heaters in the

ventilation system in the sumer.

3.21 E~RGEN:Y PROPULS ION SYSTEMS

Demonstration of emergency

modes of main plant operation and of

separate “take home” propulsion

systems should take place at the

dock. Demonstration at sea is not

regired unless dockside operationis im~ssible or it is desired to

check speed or maneuverability under

emergency propulsion.

3.22 NAVIGATION EQUIP~NT

Ship, s e~i~ent will nomally

be req ired for navigation during

sea trials. @rVility of this

e~ipent should be proven docksideprior to departure and any

additional calibration or

adjuetmentB neceseary, prfomed

during the initial phases of the sea

trials . Where calibration oradjustments at sea are necessary, it

is generally advantageous to have

the services of the manufacturer, s

representative.

3.23 DYNAMIC POSITIONING SYSTEM

(a) Dynaic positioning systems

feature microprocessor-based

control of the ship, s

poeition and movement. These

systems typically accept

inputs from a variety of

sensors and maintain the*

ship’ s speed, heading, and

position in automatic and for

manual modes by calculating

and allocating comand signals

to selected maneuvering

functions. The sensors may

include the following:

(1) Navigational inputs such

as LON and SATNAV

Global Positioning

System (GPS ).

(2) Gyrocompass.

(3) Wind speed and

direction.

(4) Doppler speed log.

(b) The maneuvering functions may

include the following:

(1) Shaft RPM.

(2) Pro~ller pitch.

(3) Rudder angle.

(4) Maneuvering thruster (s)

force magnitude and

direction.

(5) Clutch engage-disengage.

40

(c) Other features may include

incorporation of autopilot and

joystick modules allowing

operation in modes Buch as the

following:

(1)

. . .

(2)

(3)

(4)

Autopilot - Automatic

control of the ships

heading, with and

without automatic ship

speed control, and with

and without active wind

compensation.

Joystick, manual -

Manual control of the

ship’s heading,

position, and speed in a

3-axis configuration.

Joystick, automatic

heading - Manual control

of the ship’s psition

and speed in a 2-axis

configuration with

automatic control of any

operator-selected

heading.

Autotracking - Automatic

control of Operator-

selectable ship heading

and trackline (crab

angle) with and without

automat ic Bhip epeed

control.

(d) The dynaic ~sitioning system

should be tested during sea

trials. All features of the

dynmic psit ioning system

should be demonstrated. See

Figure 19 for a Data Sheet.

As an exmple, the following

teets should be conducted,

depnding on the particular

options of the eyatem:

(1) -rat ion in autopilot

mode for 15 minutes in

each of the following

conf igurat ions:

(e)

(2)

(3)

(4)

(5)

With automatic ship

speed control, at varied

headings and speeds.

Without automatic ship

speed control, at varied

headings and epeeda.

With automatic tracking,

with and without

automatic ship speed

control, at varied

speeds and headings

(crab angles) .

Operation in automatic

maneuver ing mode

(station-keeping) with

and without automatic

wind compensation at

varied headings for 1

hour.

Operation in joystick

manual mode for 30

minutee with various

cotiinations of

machinery plant

controlled functions

“on” and “off”.

Owration in joystick

automatic heading mode

for 30 minutes with

various cotiinations of

machinery plant

controlled functions

“on” and “off”.

O-ration of all

features of each remote

joystick control unit,

such as may be fitted at

bridge wing conning

stations, should be

demonstrated in each

mode.

Detail te8t procedures should

be prepared by the

manufacturer or shipbuilder

and approved by the purchaser.

41

4.0 STANDARDIZATION TRI~S

4.1 PURPOSE

Standardization trials

comprise a systematic eeries of runs

over a measured distance toestablish the relationship between

the speed, shaft horsepwer, and

shaft RPM of a ship at designated

drafts. These relationships are

re~ired for one or more of the

following purposes:

(a)

(b)

(c)

4.2

To fulfill contractual

obligations.

To obtain ~rformance data on

full-eize ships to be used in

the design of subee~ent

veesels.

To determine the relationship

between ship’s speed and shaft

RPM to be used by the owner as

an aid to navigation after

aPPIYing the corrections forservice condition.

GENE- P~

The general plan fOr

conducting standardization trials

provides for several consecutive

runs at each selected s~ed pint

alternating in direction over a

measured distance at substantially

constant shaft horsepower. The

observed s~eda, ~wera, and RPM are

averaged for each sped point.

4.3 TRIM -A

Considerations in selecting

the trial area for sped runs are

method of distance measuraent,

depth of water and accessibility to

builder’ s shipyard.

4.3.1 Fixed Ranaes

If distance is to be measured

from lantiarks, the trial area is

usually limited to one or two

locations baeed on depth of water

and accessibility. If there is a

choice, the probability of freedom

from traffic interference and fog

should govern. Fixed range runs maybe initiated and terminated by

observation of shore stations from

the ship or via telemetry by

observation of the ship from shore

stations.

4.3.2 Radiometric Ranaes

The develowent of radioposition systems makes it possible

to standardize offshore.

Satisfactory accuracy can be

obtained over a considerable area

limited only by the range and

~sition of the fixed stations.

This pmita trial area 8eleCt10n

solely on the basis of depth and

accessibility.

4.3.3 Deuth of Water

The point at which depth of

water affects a ship’s sped is

dependent on its speed, draft and

length. Minimum recommended depth

for standardization rune is given in

Section 1.0.

4.4 WIND AND SEA

The effect of wind on

standardization can be very serious

and should be considered carefully

in conducting a trial. The effect

of wind varies widely with the wind

42

direction and duration, the type of

ship, its speed, and other

conditions. It is greatest fOr

comparatively slow vessels having

high bulky superstructures relative

to the underwater body. For

exmple, a high-sided shallow draft

ship will be more affected by wind

than a deeply laden seagoing tanker.

The direction of the wind

relative to the course is also an

important factor. The lightest

resistance occurs when the relative

wind is about 25 degrees off the bow

but remains relatively high from O

to 45 degrees. The wind resistance

becomes zero when the relative wind

is slightly abaft the hem.

Although the effects of wind

described above may be largely

eliminated by analysis, the

calculation is only approximate and

therefore the correction should not

be allowed to become too great, if

accurate trial results are rewired.

Furthermore, many ships

reqire helm to counteract theaerodynamic effect of the wind.

This causes increased drag which

cannot be eliminated by any of the

customary methods of analysis.

In view of the foregoing

uncertainties, standardization data

should not be considered valid

unless true wind speda are less

than the following:

Max imum True

TvDe of ShiD Wind s~ed

High Power, hea~ ship 25 Knots

Large, passenger chip 20 roots

Smaller ships 15 Knots

4.5 NUMBER OF SPEED POINTS

If complete curves of SHP and

RPM versus speed are to be obtained,

measurements should be made at not

less than four speeds covering the

range from one-half speed to maximum

speed. Below half speed calculatedvalues are sufficiently accurate.

If a wide speed range is to be

covered, as for high-speed ships,

more than four speed points should

be used. Likewise, if the shipversus speed curves may be expected

to have definite humps and hollows,

sufficient additional points should

be taken to develop this region.

When the ship is fitted with a

controllable pitch propeller, it may

be desired to define the

speed/RPM/SHP relationship for more

than one pitch. In any case, tie

points to be measured should be

stipulated in ship’ s specif icat ions

to permit optimum echedul ing.

4.6 COURSE SELECTION

The selection of the courses

for standardization runs depends on

the t~ of measuring ranges used.

The courses for fixed ranges

are established by navigation charts

of the trial area.

The use of radiometric ranges

allows a choice of courses. The

tYP and range of radiometrice~ipent and location of fixedstations are factors in selecting

the courses. If only one shore

station is employed, the course

should be dead on or off its

peition. If two stations are

avail sble, course can be modified totake account of sea and wind

conditions if necessary. If sea or

wind are considerable, they should

be taken on the ~arter.

43

For radiometric ranges, if thefirst run at a speed point is

aborted, another run may be

immediately initiated on the sae

heading. Whether using fixed ranges

or radiometric ranges, alternate

runs should be over the a-e water.

4.6.1 Lenath of Runs

The length of the runs for

% fixed ranges is established by the

location of the markers and is

generally about one mile.

The length of runs for

radiometric ranges are limited only

: by the type of e~ipment being used;

however, runs of approximately one

mile in length are recommended. The

beginning and end of runs should be

on integral readouts of the

instrument.

4.6.2 Nutier of Runs

No less than two consecutive

runs in opposite directions should

be used to determine a speed pint.

Three rune should be conducted when

currents are known to be variable or

when fixed ranges are used.

4.7 OPE~TION OF T~ SHIP

The o-rat ing procedure, both

on the bridge and in the engine

room, should be directed toward

maintaining essentially constant

shaft horse~wer while on the

measured course. The meaeured

course must be approached on astraight run having the same heading

as the course and should be long

enough to permit accelerating the

vessel substantially to the speed

corresponding to the shaft

horsepower applied, prior to

reaching the meaeured course. This

acceleration is reqired to regain

the speed lost in turning and to

increase the speed between points.

The length of the approach run to

accomplish this is a function of the

ship’s displacement, the ship’ s

resistance characteristics, the

speed range over which the ship must

be accelerated, and the manner in

which the machinery is operated.

Three and one-half miles is anominal value which will be found

acceptable for moBt ships.

Turns at ends of the runs

should be made with not more than 10

degrees rudder, if practicable, to

avoid excessive deceleration.During the approach run, the ship

should be kept on course with

minimum rudder to retard the ship as

little as pssible. If practicable,

the run over the measured course

should be made with the rudder held

stationary at the minimum angle

necessary to maintain a straight

couree. Careful steering during the

aPPrOach run should make this~aaible. It is better to allow the

ship to swing slightly off the exact

compaee course rather than to steer

constantly. Figure 3 shows a

typical standardization course.

R1OH1 TURNUSINO 10.

I , “,,, +RuDDER

R1OH1 TURN3 + “,LES

RuDDER

- HEAOING CHANGE SHOULO BE A0JU81EDTO SUIT TuRNING CHARACTER 19T1CSVITH 10. RuDDER

FIG. 3, TYPIC- STAND~IZATION COURSE

It is essential that the shaft

RPM be steadied prior to entering

the measured course. Throttle and

machinery operating conditions

should not be adjusted during the

run. However, to shorten the

aPProach run at low speeds it ispermissible to increase the power on

the turns provided the Wwer is

decreased promptly when the ship has

straightened away. When radiometr ic

ranges are used, added pwer on

turns is facilitated by the fact

that this e~ipent can detemine

when acceleration approaches zero

and the chip’ a speed is steady.

When increasing to a higher speed

point, power should be increased

when the turn is begun. When

reducing to a lower eped pint,

power should be held until the turn

is complete.

4.8 DATA RSQUIRSWNTS

See Figure 21 for a Data

Sheet.

The following data should be

recorded during standardization

trials:

(a) Elapsed ttie for each run over

the measured distance to

detemine speed and RPM.

(b) Total shaft revolutions for

each run over the measured

dietance.

(c)

(d)

(e)

(f)

(9)

(h)

(i)

(j)

(k)

(1)

Average propeller tor~e if

torsiometer ie installed; if

not, see Section 2.0 for means

for determining shaft

horsepower.

Sufficient data to determine

the displacement and trim of

the ship.

Clock time at start of each

run over the measured distance

to identify run and for use in

the trial analysis.

Ship’s heading for each run

over the measured distance.

A record of any unusually

large rudder angles used on

the measured distance or on

the straight approach to it.

The approximate side and

direction of waves on each

run.

Wind sped and direction for

each run.

Current conditions from

current tables or from other

obaervatione euch as buoy

~sitione, for each run.

Depth of water for each run.

Temperature and density of

water in the Standardization

Area.

4.9 ORGANIZATION OF OBSER~RS

The organization of the

personnel involved in

standardization trials Bhould:

(a)

(b)

(c)

(d)

Provide for simultaneous

recording of data.

Provide for prompt correlation

and analysis of data at the

end of each run.

Provide for duplicate

measurements to insure that an

error or failure of one

observer or instrument will

not reBult in the 1088 of a

run.

Provide for clearly defined

responsibilities with a single

person in charge of run

select ion and acceptance.

4.10 INSTRU~NTATION FOR

sTAND~ IZATION DATA

The following paragraphs

recomend the methods for obtaining

the data rewired in paragraph 4.8.

Details of instrumentation

installation, calibration and

operation are covered in Section 5

of this guide.

(a) Elapsed time for each run ie

to be taken by at least two

independent obeervero using

separate time devices. For

radiometric ranges, the thing

devices may be actuated from a

Bingle source.

(b) Total shaft revolutions fOr

the runs are to be obtained by

total izing countere. A

specially installed trials

counter should be ueed for the

primary source of revolution

and the ship’ e counter may be

used as a backup.

(c)

(d)

(e).

(f)

(9)

(h)

Average propeller tOrque

should be determined from a

torsiometer. If a torsion-

meter is not installed, see

Section 2.0 for means of

determining shaft horsepower.

Drafts should be taken in a

sheltered location prior to

the standardization trials

which is generally at the

builder’s yard. It may be

helpful to those persons

obtaining draft mark readings

to make observations from a

small boat. The density of

the water in which the ship is

floating should be measured to

convert these drafts to

displacement. Obtaining

measurements of the density of

the water is usually not

imperative. See paragraph

4.14. All Significant changes

of loading taking place

between the time of this

determinantion and the

standardization runs should be

applied to determine truedisplacement for each run.

The bridge clock should be

used as the official time of

day for standardization runs.

All ship’s and trial’ s clocks

should be synchronized before

the start of the trial.

Ship’ e heading should be taken

from the bridge compass.

The size and direction of the

waves for each run should be

obtained from an expr ienced

bridge observer.

Wind spsed and direction

should be obtained with an

anemometer and wind direct ion

indicator.

46

(i) Depth of water over the

measured distance may be

obtained from the ship’ s

sounding e~ipment or may be

taken from published data.

4.11 COORDINATION PROCEDURE

The following procedures may

be used as a guide to give

satisfactory coordination of a

standardization run. For this

se~ence it is aeeumed that the ship

is in the standardization area and

on the approach leg for a

standardization run:

(a)

(b)

(c)

(d)

(e)

(f)

(9)

(h)

(i)

(])

(k)

(1)

check that RPM is correct and

propulsion plant is steady.

Check that course is correct

and area is free of traffic.

Check that tor~e is steady.

Check for zero acceleration if

radiometric device is being

used.

Give “standby signals. ”

Give “mark” signal to start

the run.

Monitor data for evidence of

deviation.

Give “standby signals. ”

Give “mark” signal to end the

run ...

Evaluate results of the runand announce the next run.

Alter heading for leg toward

turn.

Make turn to reciprocal

course.

4.12 TOLERANCES AND LIMITS

The acceptable tolerances and

limits for standardization trials

are provided by Figure 4.

Tolerance~ or Limit

Difference in time by

separate timing devices

for a run

Difference in tOtal

revolutions from

separate revolution

counters for a run

Differerice in RPM fOr

each run from mean for

each speed PO int

0.25%

0.20%

2.0 %

Difference in RPM of

any shaft of a multi-

screw ship from the

mean for a run

provided the rated

RPM for all shafts

is the sme 2.0 0

FIG. 4, STANDARDIZATION TRIAL

TOLEWCES AND LIMITS

4.13 DATA WDUCTION

During the trial, running

plots of RPM, SHP and speed should

be made to check the accuracy and

completeness of the data and proper

functioning of the instruments. If

plots are not smooth, prtinent logs .

and records should be exmined

critically.

Data from separate

observations should be plotted

separately. If variance exceeds

limits prescribed above, the values

which plot smoothly with prediction

may be retained and the miefit

values discarded.

47

After the trials are

completed, the data should be

averaged, instrumentation

corrections applied, and the results

tabulated and plotted. The RPM, SHP

and speed for each speed point

should be obtained by averaging the

data from the two runs in opposite

directions. If three runs are used,

the run in one direction should be

double, weighted when averaged with

the two runs in the other direction.

For Trial Data and Report, see

Section 6.0.

4.14 CO-CTIONS

When standardization trial

conditions are within the limits

recommended in this section,

corrections to trial data are not

considered necessary and trial

results may be reported as obtained.

If recommended trialconditions cannot be met d“e to

limited depth of water or “ind

conditions in the trial area, then

corrections should be applied to the

trial results and included in the

trial report.

Corrections for water

temperature and density are normally

of a minor magnitude and normally

need not be included in the trial

report.

corrections to standardization

resulte and methods of analysis are

included in the Principles of Naval

Architecture, Vol. II, published by

The Society of Naval Architects and

Marine Engineers, 1988.

48

5.0 INSTRU~NTS ANO APPARATUS FOR SHIP ‘S TRIALS

5.1 GENERAL

5.1.1 Introduction

The type and condition of the

instruments and apparatus which

provide data for evaluating the

performance of a ship system are

essential in determining instrument

acceptability. The instrument type,

precision and the sea trial

instrument plan beyond the ship’s

instrumentation should be specified

in the contract. Instruments should

be selected on the basis of ship

system performance re~irements and

on the basis of the conse~ential

coot for departures from ship

systems target performance. If the

contract and specifications are

silent, it is essential that the

shipbuilder prepare a suitable sea

trial instrumentation proposal and

calibration procedure. It is

important to obtain the owner’s

concurrence at an early date eo that

the necessary provisions can be

incorporated in the original design

and other long lead time actions can

be initiated as rewired.

This section states the types

of instruments available for

measurement of each physical

~antity pertinent to ship’s

machinery and systems.

Characteristics of each ty~ of

instrument, which affects its

applicability to ship “se, iediscussed briefly, leaving the

general characteristics and

installation methods to be discussed

by reference to existing

publication. Where such material

is not avail~le or where

instruments or techni~es are

peculiar to sea trials, a more

extensive coverage is provided.

5.1.2 References

The Werican Society of

Mechanical Engineers has published

Performance Test Codes (PTC) for

testing of land plants, and has

published Supplements on Instruments

and Apparatus which describe each

tYPe Of instrument and thecapabilities and limitations of

each. See references (a) and (b )

for additional information. In most

publications the inherent precision,

calibration procedures and

installation instructions are

included. The Naval Ship

Engineering Center has published

“standards” which provide details on

the installation of sensing

connections and other information

pertinent to shipboard measurements.

These documents are listed below and

are referenced in the pertinent

portions of the text of this

section.

(a)

(b)

(c)

General Instructions,

Performance Test Code,

Fairfield, N.J. , The

tierican Society 0f

Mechanical Engineers,

PTC 1 - 1986

code on Definitions and

Values, Performance Test

Code, Fairfield, N.J. ,

The Werican Society of

Mechanical Engineers,PTC 2 - 1980 (R1985)

Temperature Measurement

Performance Test Code,

Fairfield, N.J. , The

49

Werican Society of

Mechanical Engineers,

PTC 19.3 - 1974 (R1986)

(d) Guidance for Evaluationof Measurement

Uncertainty in

Performance Tests of

stem Turbines,

Performance Teat Code,

Fairfield, N.J., The

~erican Society of

Mechanical Engineers,

PTC 6 Report - 1985

(e) Lempa, M.S. , editor,

Instrument Standards,

Naval Ship Engineering

Center, Philadelphia

Division

(f) Pressure Measurement

Performance Test Code,

Fairfield, N.J. , The

tierican Society of

Mechanical Engineers,

PTC 19.2 - 1964

(9) Application, Part II ofFluid Meters: Interti

Supplement on Instrment

and Apparatus,

Fairfield, N.J. , The

herican Society of

Mechanical Engineers,

PTC 19.5 - 1972

(h) Sean, Howard S. , Fluid

Meters - Their Theory

and Application, 6th

edit ion, New York, The

tierican Society of

Mechanical Engineers,

1971

(i) Miller, R. W., F1OW

Measurement Engineering

Handbook, New York,

McGraw-Hill Book Co. ,

1983

(]) Stein, Peter K. ,

Measurement Engineering,

Phoenix, AZ, Stein

Engineering Service

Inc. , 1964

(k) Electrical Measurements

in Power Circuits, Part

6, Performance Test

Code, Fairfield, N.J. ,

The tierican Society of

Mechanical Engineers,

PTC 19.6 - 1955

(1) Measurement of Indicated

Power, Performance Test

Code, Fairfield, N.J. ,

The herican Society of

Mechanical Engineers,

PTC 19.8 - 1970 (R1985)

(m) Gas Turbine Power

Plants, Performance Test

Code, Fairfield, N.J, ,

The tierican Society of

Mechanical Engineers,

PTc 22 - 1985

(n) Stem Turbines,

Performance Test Code,

Fairfield, N.J. , The

tierican Society of

Mechanical Engineers,

PTC 6 - 1976

(0) ApPndix A to Test Codefor Stea Turbines,

Performance Test Code,

Fairfield, N.J. , The

tierican Society of

Mechanical Engineers,

PTC 6A - 1982

(P) Measurement of Shaft

Power, Performance Test

Code, Fairfield, N.J. ,

The tierican Society of

Mechanical Engineers,

PTC 19.7 - 19S0

50

(q) Measurement of Rotary

Speed, Performance Test

code, Fairfield, N.J. ,

The ~erican Society of

Mechanical Engineers,

PTC 19.13 - 1961

(r) Code for Shipboard

Vibration Measurements,

Jersey City, N.J. , The

Society of Naval

Architects and Marine

Engineers, 1975, Book

No. C-1

(s) Machinery Vibration

Measurements, Jersey

City, N.J. , The Society

of Naval Architects and

Marine Engineers, 1976,

Book No. C-4

(t) Acceptable Vibration of

Marine Stem and Gas

Turbine Main and

Auxiliary Machinery

Plants, Jersey City,

N.J., The Society ofNaval Architects and

Marine Engineers, 1976,

Book No. C-5

(u) Ship Vibration and Noise

Guidelines, Jersey City,

N.J., The Society of

Naval Architects and

Marine Engineers, 1980,

Book No. 2-25

(v) Guidelines for the Use

of Vibration Monitoring

for Preventive

Maintenance, Jersey

City, N.J. , The Society

of Naval Architects and

Marine Engineers, 1987,

Book No. 3-42

(w) Measurement of

Industrial Sound,

Performance Test Code,

Fairfield, N.J., The

~erican Society of

Mechanical Engineers,

PTC 36 - 1985

(x) Boilerwater/Feedwater

Test and Treatment,

Naval Ships Technical

Manual S90B6-GX-STM-02,

Chapter 220v2, 15

Oecefier 1987

(Y) Design of Dissolved-

Oxygen Testing Cabinet,

U.S. Naval Engineering

Experiment Station,

February 29, 1940,

Re~rt No. B-1158

(z) White, Alfred H. , The

Determination of

Dissolved Oxygen in

Boiler Feedwater, Joint

Research Comittee on

Boiler Feedwater

Studies, October 1967,

Project No. 767

(aa) Standard Test Methods

for Dissolved Oxygen in

Water, Philadelphia, PA,

herican Society for

Testing and Materials,

ASTM Designation DB8B-B7

(ab) Density Determination of

Solids and LiWids,

Performance Test Code,

Fairfield, N.J. , The

Merican Society of .

Mechanical Engineers,

PTC 19.16 - 1965

51

(at)

(ad)

(se)

(af)

(&g)

Determining the

Concentration of

Particulate Matter in a

Gas Strem, Performance

Test Code, Fairfield,

N.J., The Werican

Society of Mechanical

Engineers, PTC 38 - 1980

(R1985)

Flue and Exhaust Gas

Analysis, Performance

Test Code, Fairfield,

N.J., The berican

Society of Mechanical

Engineers, PTC 19.10 -

1981

Water and Stem in the

Power Cycle (Purity and

Quality, Leak Oetection

and Measurement ),

Performance Test Code,

Fairfield, N.J. , The

~erican Society of

Mechanical Engineere,

PTC 19.11 - 1970

Oeterminat ion of the

Viscosity of Lipids,

Performance Test Code,

Fairfield, N.J. , The

Werican Society of

Mechanical Engineers,

PTC 19.17 - 1965

Measurement of Time,

Performance Test Code,

Fairfield, N.J. , The

~erican Society of

Mechanical Engineers,

PTC 19.12 - 1958

NOTE : ASME Publications are

available from The Merican Society

of Mechanical Engineers, Marketing

Department, 22 Law Orive, Box 2350,

Fairfield, N.J. 07007-2350. SNAMS

Publications are available from the

Publ icat ions Department, The Society

of Naval Architects and Marine

Engineers, 601 Povonia Avenue,

Jersey City, NJ 07306. Various

Naval publications are available

from the Comanding Officer, Naval

Publications and Forms center, Attn:

Code 106, 5801 Tabor Avenue,

Philadelphia, PA 19120-5009. ASTMpublications are available from The

herican Society for Testing and

Materials, 1916 Race Street,

Philadelphia, PA 19103.

5.2 TEMPERATURE MEASUREMENTS

5.2.1 TvDes of Instruments

Five types of instruments are

comonly used for temperature

measurement. These are:

(a) Thermocouples

(b) Li~id-in-glass

thermometers

(c) Oistant-reading vapor

pressure thermometers

(d) Resistance thermometers

(e) Bimetallic thermometers

All typs are readily

available from reliable makers. For

descriptions, characteristics and

application, refer to reference (c ).

5.2.2 Thermowells and TemDorary

Installations

Most permanent installations

have the temperature measuring

devices installed in a thermowell

which is hersed in the fluid whose

te,m~rature is to be measured. Due

to coat, temyrary installations

‘“ such as for sea trials, do not

always warrant the installation of a

tem~rary themowell during the

vessel, s design stage. Li~id or

bimetallic themometers strapped on,

or distant reading the nutiers with

sensing elemente secured to the

surface to be measured have been

used with some success when rapid

52

fluctuations are not involved and

precision is not rewired. Securing

the thermocouple shorted ends to the

fluid container at the point to be

measured by drilling a shallow small

hole in the surface and peening-in

the thermocouple wire has been

successful where rapid fluid

temperature changes are not

involved. The recommended procedure

for the installation of tem~rary

thermocouples or li~id thermometers,-.. is to remove an existing ship’s

thermometer and insert the sea trial

measuring device in the ame

thermowe 11. The thermocouple should

be in solid contact with the bottom

of the thermowell and for high

temperatures should be packed with a

suitable material. A thermocouple

installed in this manner will sense

changes in temperature rapidly

enough for sea trial re~irements.

To insure precision of fluid

temperature measurement,

consideration must be given in

locating the sensing element to

sense an average smple of the

fluid. Where high preseures are

involved, a thermowell is the safest

installation.

5.2.3 AdaDters for Seneina Elements

If pressure, velocity and

temperature are moderate, the

temperature sensing element of the

measuring device can be introduced

through a pressure gage teSt

connection and held in place by an

adapter. The adapter must be

designed as a pressure boundary.

5.2.4 Instrument Compatibility

Temperature MeaSuring

instrumentation should be compatible

with the pressure and tem~rature in

the system in which it ie to be

used.

5.2.5 Calibration and Sea Trials

It is recommended that theship, s temperature instrumentation

intended for use in obtaining sea

trial data and all sea trial

temperature instrumentation be

calibrated in the shop or on the

ship where practical within a two

week period prior to sea trials. It

is further recommended that the

means for verifying the accuracy of

imprtant thermometers be avai lab leduring sea trials.

5.2.6 SDecial TherMOCOuDleS

Special thermocouples may be

made to suit retirements.

Instructions and material for the

fabrication of thermocouples are

outlined in the Instruments

standards publication referenced in

reference (d). A pressure test of

these thermocouples is essential for

safety.

5.3.1 TYPes of Instruments

Pressure measuring instruments

generally are constructed to measure

the difference between the ~ient

atmospheric pressure and the

pressure in a pipe or a pressure

veseel. Indicating gages for

preaaure measurement are visually of

the elastic tw, i.e. , Bourdon

tube, bellows or diaphram. For

these, pressure is transmitted to an

elastic me~er and the resultant

motion displayed using a suitable

scale.

The following ty~s are

readily avail~le from reliable

makers:

(a) Bourdon typ gages - The

most comon preseure

measuring devices for

vacuum, low, medium and

high pressure.

53

(b)

(c)

(d)

(e)

(f)

Transducers - Convert

pressure into pneumatic

or electrical signals.

They are utilized for

remote eensing,

particularly on

automated ships.

Bellows gages - Utilized

for mea9uring low

pressure differentials

up to 50 PSI.

Diaphra~ gages -

Utilized for pressure

O-1 inch HG to 200 PSIG

range and are adaptable

for use with corrosive

fluids of high

temperature and high

viscosity.

Deadweight gages -

Installed for trials

where great accuracy is

re~ired. They can be

used only for systems

without major pressure

fluctuations.

Li@id column gages

(Manometers) - Utilize a

variety of li~ids in

various hollow tube

configurations and are

used to measure gage,

differential,

atmospheric, vacuum, or

absolute pressure.

5.3.2 Proner Connections and

PrOtectiOq

Careful consideration ehould

be given to the location and

installation of the gages, pressure

sensing connect ions to the ship

eymtem and pressure gage sensing

lines configuration to maintain the

gage sensing lines empty or full of

li~id. Vacuum 1ines should be

self-draining or be provided with

loop seals to establish a knownwater leg. Means of venting gagelines should be provided adjacent to

the gage or other euitable place.

Gages should be connected to stem

lines with a loop seal in the

sensing line near the gage to

protect the Bourdon tube from high

temperature.

Bourdon type gages should be

protected from shock, violent

preesure pulsation, and high

temperature. The gage should be

located in a zone of normal room

temperature, protected from direct

radiation and hot surfaces, and

carefully mounted to avoid

distortion or warping of the gage

case.

5.3.3 Zero Adiust for Elevation

Pressure gages installed in

li~id and stem systems for test

data should be zero adjusted for

difference in elevation between the

gages and their sensing points,

where the adjustment exceeds the

precision tolerance specified for

the gage. The gage tolerance ehould

not be greater than k one smallest

scale division of the gage. Li~id

gage sensing lines ehould be vented

of gases to ensure that they are

full of li~id. stem gage sensing

lines should be full of water when

zeroing the gages, either from

prebilling or from service

condeneat ion. Steps should be taken

to ensure that vacuum gage sensing

lines are empty. When ship’s

instrumentation is used for trial

pur~aes, the correction for

elevation dif ferencee between the

gage and the sensing line connection

to the ship system should be noted

on the data sheet. This information

should be so noted at the gage also.

For installation and procedural

steps to avoid water-leg error see

reference (e) .

54

5.3.4 Calibration and Sea Trials

It 1S recommended that theship qs pressure instrumentation

intended for use in obtaining sea

trial data and all sea trial

pressure instrumentation be

calibrated in place within a two

week period prior to sea trials. It

is further recommended that the

means for calibration of imprtant..

gages be available during sea

“““trials.

5.3.5 Barometers

Barometers measure atmospheric

preseure, and this information is

rewired for determining absolute

pressures from readings on Bourdon

gages, deadweight gages, and

open-end oil, mercury or water

columns. Barometers are of two

kindB, aneroid, i.e. , bellowB type,

and mercury column. Either type, if

properly designed, manufactured and

calibrated, and carefully handled,

will be satisfactory. The barometer

should be located in the Bme

compartment as the instruments

rewiring correction to absolute

values. Barometers can be

calibrated by a U.S. Weather Bureau

Station. When an absolute pressure

gage is used, no barometer

correction is necessary. See

paragraph 5.3.9.

5.3.6 Manometers

Manometers, also bom as U-

tube ty~ gages, are livid col~n

gages that are widely used for

measuring relatively small

differences in gas pressure, viz,

differences between a gas pressure

and the atmosphere, or other

pressure differential. They have an

indication Bcale stated in inches,

generally, which is attached beBide

the li~id colmn.

Li~ids of different specific

gravities may be uBed, the most

comon are: oils of various specific

gravities, mercury and water. It isimportant that the een Bing fluid be

distinguishable from and compatible

but not miscible with the fluid

being sensed. Fluids must be clean

to avoid accumulation of dirt at the

interface or on the glass tubing

which would obscure readings.

COIUMnS should be mountedvertically. The u8e of inclined

gages at sea is not advised as they

are affected too much by the motion

of the ship.

Mercury filled gages should

not be used on systems containing

cop-r or its alloys; if the mercury

escapee into the system, these

materialB are degraded by

malgmation.

Manometers installed on a

high-pressure line should be

provided with cutoff valves and a

valved croBB-connection to make it

possible to avoid blowing out the

li~id when putting the gage on the

line. They must be carefully

deeigned and constructed to

withstand their rated operating

preesures, which should not be

exceeded for safety reasons.

5.3.7 Manometers For Flow

Measurement

ManOmeterB, for measuring

differentials across flow nozzles or

orifices at high pressure, may be

purchased from makers of such

e~i~ent.

5.3.8 Liaid Columns

LiWid columns for use at ornear atmospheric preesure are simple

to design and inetall, and the use

of rubber or synthetic hose of a

55

good grade is satisfactory for

making connections to ordinary glass

or plastic tubing. Generally, no

indicating scale is provided with a

li~id column. It is important to

provide enough column height to

avoid a blowout of the sensing fluid

in either direction or add float

check valve5 for that purpose.

5.3.9 Zimerli Gaae

The Zimerli gage is a

dependable manometer which has all

the desirable features of a

manometer but none of its

disadvantages. It is easily and

rapidly filled, and boiling of the

mercury to remove air is totally

unnecessary. The Zimerli gage is

always in working condition, since

any air which may have entered the

reference lifi can ~ickly be

removed without disconnecting the

gage. The glass will not be broken

by a sudden release of the vacuum.

5.3.10 Absolute Pressure Gaaes

These gages are special

mercury columns with one end

evacuated and sealed, so that the

gage may be used directly to measure

absolute pressure. See reference

(f). They are very useful for

measuring condenser preesures and

may replace an opn-end mercury

column and barometer.

5.3.11 Gaae Protection From

Pressure Pulsation

When measuring a hydraulic

system pressure subject to severe

pulsation, dapning ehould be

provided either by installation of

snubbers or judicious throttling of

the gage cutout valve.

5.3.12 Further Information

Reference (f) provides a

complete description of the t~s of

pressure measuring instrumental ion,

the installation, and calibration

procedures for each.

5.4 FLOW WASU~~NTS

5.4.1 Tvpee of Instruments

During sea trials, flow may be

measured by positive displacement

meters, turbine meters, variable

area meters, metering flow nozzles,

orifices or venturi tubes.

5.4.2 Positive Displacement Flow

~

A positive displacement flow

meter may be of either the rotating

disk or piston type. Prior to

installation for sea trials, meters

involved in determining propulsion

plant performance should be

calibrated over the expected flow

range using a fluid at the sme

viscosity and temperature as

expected to be measured during sea

trials. Unless specified, post sea

trial calibrations of meters should

not be rewired if trial results are

as predicted. The following

instructions should be followed

during the installation and use of

~sitive displacement trial meters:

(a)

(b)

(c)

Meters should be mounted

in the horizontal

psition.

Dirt or other foreign

matter should be kept

out of the meter during

installation and use. A

strainer installed

upstrem of a sea trial

water meter is

desirable.

Meters should be

installed and back

pressure maintained

that they will be kept

filled with li~id at

all times. This is

56

. (d)

(e)

(f)

(9)

(h)

particularly important

when measuring hot

fluids where pressure

changes close to the

meter can cause the

fluid to flash into

vapor. Air or vapor

passing through a meter

will produce an error in

the reading and may

d-age the meter.

Meters should be located

on the discharge side of

the pump and preferably

on the inlet side of

heaters. Pressure drop

across the meter at

maximum expected flow

should be determined ad

included in the system

design.

If a control valve is

used, it is preferable

to locate it on the

discharge side of the

meter.

Meter should be used to

measure only the limids

for which it was

designed.

The meter size should be

chosen so that it will

operate as near ite

rated capacity as

~ssible. When

precision is rewired

readings belw 10

prcent of the rated

meter capacity should be

avoided.

Since these meters are

essentially volume-flow

measurement devices, the

density of the fluid

passing through the

meter must be known, for

masm-flow rate

(i)

(])

(k)

determination. This

reqires precise

temperature measurement

of the fluid in the lineconnected to the meter.

Upstrem fluid

temperature is

preferred.

Meters of this type are

usually designed for and

made of material having

specific temperature

limits, which should not

be exceeded. The

operating temperature

range for any meter will

be provided by the

manufacturer.

The precision of these

meters is degraded by

fluid densities errors,

wear, corrosion, dirt

deposits, and friction.

Care should be exercised

to eliminate these

causes of errors insofar

as possible.

Systems should be

thoroughly flushed

before the installation

of meters. Pre-Sea

Trial operation of the

system should be

perfomed without meters

unless checking meter

operability. This will

help prevent meter

mal funct ion during

trials due to dirt

accumu lat ion.

5.4.3 Meter Installation For

Prec i8e Measurement 8

For precise li~id

measurements, e.g. , fuel or water

rates for guarantee purpses, two

identical peitive displacement flow

meters installed in series are

57

recommended to insure no loss of

data due to failure of a meter, and

to provide a check measurement. If

meter bypasses are installed, each

should be fitted with two block

valves and a vent bet”een them so

that absolute closure can be

verified. A preferred arrangement

is to provide individual bypass

lineS fOK each meter with the meter

isolating valve and differential

pressure gage connected to

the meter inlet and outlet to

indicate when the meter is sticking.

A smpling connection should be

provided in the active line upstrea

of the meter.

5.4.4 Orifice Plate, Flow Nozzle.

and Venturi Tube

Fluid flow measurement may

also be accomplished by differential

pressure measurement across an

accurately designed orifice plate,

flow nozzle or venturi tube.

Reference (g) provides a complete

description of orifice, flow nozzle

and venturi flow measurement design

and installation procedures

including differential pressure

indication secondary element

identification. See the meter

manufacturer’ s information for

specifics about the accuracy and

installation re~irements.

5.4.5 Indicating and Recordinq

Mechanism for Orifice Plate.

Flow Nozzle, and Venturi Tube

Comercial flow meters of the

orifice or nozzle t~ ueually

include an indicating and recording

mechanism. The errors in this

mechanism, due to friction and pa-r

displacement, may be detemined by

connecting a suitable li~id colum

differential pressure gage in

parallel with the indicator or

recorder to obtain a direct reading

of the differential. To convert

this reading to a mass flow value,

it is necessary to know the absolute

pressure upstream of the device, the

fluid temperature, the size and type

of orifice or nozzle, the ineide

di-eter of the pipe, and the flow

coefficient of the orifice or

nozzle. References (h,), (i) and (j )

will be helpful for this

determination.

5.5 TORQUE AND HORSEPO~R

~ASURS~NTS

5.5.1 HorseDower Determined

Indirectly

Shaft horsepower is the

primary performance parmeter for

ship propulsion plants. It may be

determined by measuring shaft RPM

and mean indicated pressure of a

piston engine, the electrical input

to a propulsion motor, or the flow

and qality of ste- to a propulsion

turbine. However, these methods

lack precision and are dependent on

dimensional and/or efficiency data

or estimates furnished by the

manufacturer of the machinery being

tested.

For methods of determining

horsepower which do not involve

direct measurement of tor~e,

consult references (k), (1) , (m) ,

(n), (o) and (p).

5.5.2 HorseDower Determined

From Tor~ e Measurements

Propulsion horsepower derived

from propel ler shaft tor~e and

revolutions over a measured time

interval ia more exact and provides

the desired inde~ndence. Some ship

installed systems have horsepower

measurement and indicator syetems

which electronically integrate

tor~e and RPM signals. Such

systems are valuable for trend

studies of ship

lack precision,

cal ibrat ion and

operation but can

convenient

zero setting

58

features. However, comercial

torsiometers are available with

sufficient precieion and

reliability for use during sea

trials. The calibration of ship

installed systems may need to be

accomplished using a sea trial

torsiometer.

Torsiometer installation,

calibration, and checkout for use on

sea trials, should be supervised by

competent personnel, preferably by

those who have had actual

installation, calibration, and

operating experience with the type

of meter selected or have been

specially trained for these tasks.

Installation, calibration, and

operating instructions are provided

by the e~ipment manufacturer, and

they should be followed explicitly.

5.5.3 Shaft Torsiometers

A shaft torsiometer is an

instrument for measuring the

torsional deflection of a shaft,

over a known portion of its length,

while the shaft transmits power from

the engine to the propeller. Since

torsional deflection is proportional

to the transmitted tor~e, it can be

cotiined with measured shaft

revolutions per minute and Buit able

calibration and physical constants

to calculate shaft horsepwer.

Torsiometers differ chiefly

in the method of gaging torsional

deflection. The following typs are

available:’

Variable mutual- inductance

gages

Resistance-wire strain gagesAcoustic-wire strain gages

Phase-shift gages

Permeability-magnet ic

Technical endorsement of any

tYPe Or make of torsiometer iscontrary to Society Wlicy; however,

the following guidelines should be

observed in making a selection of

trial meters to provide data for

demonstration of power or fuel rate

contractual requirements:

(a)

(b)

(c)

(d)

(e)

Inherent accuracy should

be better than design

margins.

Zero tor~e meter

readings should be

determinable during

shaft calibration and at

sea.

Meter should be suitable

for taking shaft

calibration readings.

All components should be

sufficiently rugged and

provided with sufficient

protection to operate

indefinitely in the

adverse environment

usual for ship

installations.

Meter should be capable

of operating on the

~ality of electrical

pwer available on

ships.

The output of tor~e measuring

devices have been integrated with

shaft RPM and designed to read power

directly as a ~manently installed

system on ships. Secondary

instrwent errors may contribute to

overall inaccuracy of these systems

and make their use for sea trials

unsuitable except as a check

instrument. There are benefit e to

having these meters as a backup to

the sea trial torsiometers. The

shipboard meter may be used as the

sea trial meter when the owner and

contractor agree during their sea

trial planning. See reference (p).

59

5.7 SHAFT THRUST~TERS

5.7.1 Purpose of Thrustmeter

A thrustmeter is an instrument

for ensuring the thrust developed by

the propeller in the axial direction

of the shafting. By cotiining the

thrust with the measured speed of

the ship, the thrust horsepower can

be calculated and compared with

model test data.

5.7.2 Useful Installations

Although the thrustmeter is

not a re~ired instrument for

acceptance trials, it may be desired

to install such an instrument on

“first of a class” ships having an

innovative propeller design or a

stern configuration where an

evaluation of the design propulsion

factors is deBired. Thrustmeter

data in conjunction with other

standardization sea trial data

afford the only practicable means of

breaking down the propulsive

efficiency into its various

components; it is the only means of

evaluating the performance of a

full-sized propeller and of

determining the resistance of the

ship as a check against model scale

factors.

5.1.3 TvDes of Instrument@

All thrust-measuring devices

which have been employed in recent

years for shipboard testing belong

to one of ..three general typs. They

may be described as those in which

the thrust is measured by:

(a) Defamation of an

elastic meber.

(b) Hydraulic pressure in

cells.

(c) Strain gage load cells.

Any of these types can be designed

to suit the range of thrust expected

and the configuration of the ship, s

propulsion and provide satisfactory

data. If a thrust meter is

specified, the type and design must

be established in the early design

stages of the power train.

Accordingly, instrument

manufacturers must be consulted at

that time, and all details of

configuration and operation obtained

from them. Accordingly, no attempt

will be made here to provide such

information.

5.8 SHAFT SPEED ~ASURE~NTS

5 .8.1 Propeller Revolution Counters

Preferably, propeller shaft

speed should be obtained from dual

propeller revolution counters which

can be shifted electrically on a

signal. Counters may be actuated by

electrical impulses initiated by

interrupter slip rings located on

the main shaft, or by micro switches,

or by selsyn units driven by any

element in the main propulsion

train. Care must be taken to have

slip rings clean, smooth, and round

to avoid false counts.

Electric countere located in

the computing room, shifted either

locally or from range observation

stations, can be used to obtain

total revolutions for a run. When

standardizing a ship, an observer at

a range station operates the

shift-switch at the beginning and

end of a run. The counter in use is

read and reset to zero by the

computer room observer before the

next run. When not atandardiz ing,

the electric counter may be shifted

by the trial signal system. The

ship’s counter should also be read

on the sme interval as the electric

counter to obtain accurate backup

data.

60

For trials that do not includestandardization or accurate fuel

rate and water rate measurement, the

installation of special counters is

not essential . Sufficient accuracy

is available from the permanently

installed revolution counters read

on the same established time

interval as the sea trial signal

system.

. Ship’ s shaft speed indicators

- .in the engine room and on the bridge

should be adjusted for minimum error

over the operating range prior to

sea trials. This rewires

detachment from the sensing point

and driving the transmitter through

the operating speed range at known

RPM . All receivers which will be

simultaneously operative should be

actuated when calibrating.

During sea trials, accuracy of

shaft speed indicators should be

checked by comparison with counters.

The accuracy of the shaft

revolution signal is particularly

important when it is used as a

control element.

5.8.2 Portable Tachometers and

SDeed Indicators

Portable tachometers and speed

indicatOrB are used to obtain

rotating speeds of auxiliary

machinery during sea trials and are

not subject to the precimion and

reliability rewired of pro~ller

revolution measuring e~iwent.

When instantaneous speds are

necessary to evaluate transient

conditions, s~ed recorders should

be used. Recorders may be actuated

by calibrated tachometer generators

or electromagnetic pickups driven by

the unit to be obeerved. Somet ties

the signal for the installed

tachometer can be utilized to drive

the recorder.

When totally enclosed

machinery is used it may be

difficult or sometimes impossible to

reach the shaft with the ordinary

tyPe Of tachometer, and in suchcases the vibrating-reed frevency

indicator may be used. Care must be

taken to avoid reading harmonics of

the fundamental speed.

The stroboscopic

speed-measuring instrument may be

useful for measuring fre~ency of

motion of any moving part which is

visible but where a mechanical

tachometer is not suitable. These

instruments operate on the

principles of interrupting vision at

the sme fre~ency as the motion,

whereby the moving part appears to

stand still. The instrument has a

fre~ency indicator to determine the

fre~ency at which mot ion stops.

Stroboscopes will also stop motion

when they are set at any multiple of

the speed of the machine. The

operator should preset the

stroboscope at the expected

fundamental speed to avoid errors.

5.8.3 Additional Information

For further details about

tywe Of instruments and precautionsfor their use to measure shaft speed

see reference (q).

5.9 VIBRATION ~ASU~~NTS

5.9.1 Oerview of Measurement and

AnalvBis

Vibration measurement and

SpCtrum analySiS Syetems vary withtheir functional application. They

may be adapted for measurement ofhull structure, of pints selected

from observing and exploring

vibration patterns or of pints of

interest in the propulsion plant and

auxiliaries. Data may be directly

recorded in visual fore, or be

recorded on magnetic tap, or in a

. .01

portable computer data base for

later translation and presentation.

Transducers applied to the surface

to be measured may be sensitive to

velocity or acceleration, and may be

held by hand, by adhesive or by

straps. Electronic circuitry may

~Plify and differentiate Orintegrate the signal to provide an

output proportional to displacement,

velocity or acceleration, as

selected. The total output may be

graphically recorded at selected

chart speeds, or an analyzer may be

interposed with filter circuits to

separate the signal into its

proportionate fre~ency bands.

Bands may be wide or narrow. The

selection of these features is

dependent on contractual

re~irements, the e~ipment

available, and the circumstances

encountered. The time and personnel

available must be considered.Portability of e~ipment is also a

major consideration.

5.9.2 Emipment For Sea Trials

In general, electronic data

and analyeis thereof is not reqired

unless the vibration encountered

appears excessive to the physicalsenses; however, vibration which

seems excessive to the physical

senses is often found not so when

measured with sophisticated

e~ipment. Accordingly, unless the

contract is to the contrary, it is

an acceptable practice to carry a

full range of calibrated vibration

and spectr~ analyzing e~i~ent on

sea trials to be used if a vibration

problem is suspected. If the

establishment of a vibration

baseline is spcified in the

contract then the e~i~ent will be

carried on sea trials.

5.9.3 StOrina Vibration Data

The practice of magnetic

taping vibration signals or filing

them in a data base for pssible

future interest has many advantages.

It permits one team to collect more

data in a limited time; it permits

data analysis under laboratory

conditions on return to port with

laboratory instruments or personal

computers. If the results of data

analysis are not needed at sea, the

saved data can be translated and

analyzed off site under more

favorable condit ions.

5.9.4 Compatible Em iument

Vibration pickups, mplif iers,

and data analysis and readout

eviPment are available incompatible configurations from

reliable manufacturers. Reliable

information as to capabilities,

calibrat ion, and operation is

readily available from manufacturers

and will not be described in this

guide.

5.9.5 Data Collection

Good practices for obtaining

vibration measurements include the

following:

(1) Calibrate all components

on a prescribed schedule

and apply calibration

factors to reported test

data values.

(2) Record and apply gain

settings to all data

taken.

(3) Label each vibration

data record with ship, s

rime, trial nutier,

date, time of day,

e~i~ent n-e, unit

no. , plant RPM and

maneuver or operating

condition, orientation

and location of the

pickup, type of pickup

installed, instrument

serial nutiers, and any

other matters ~rtinent

62

to understanding and

interpreting the data.

(4) Mark the event rime, RPM

signals, time, and

calibration lines traced

on the charts to

correlate vibration data

with interpretive

information.

5.9.6 Additional Information

For further information on

vibration measurement techni~e,

e~ipment and analysis, cone”ltreferences (r), (s), (t), (u) and

(v) and the manufacturer’s

literature.

5.10 AIRBORNE NOISE ~ASURE~NTS

5. 10.1 Purw se of Sea Trial

Measurements

Airborne noise measurements

need to be per fomed during eea

trials to pro~rly evaluate the

ship, s airborne noiee levels.

Airborne noise measurements of all

ship spaces while there are

machinery and eyeteme o~rating

without the propulsion plant

operating can be per fomed best

during dockside operation prior to

sea trials. However, there is no

substitute for an overview noise

measurement survey of all ship

spaces measured prior to sea trials

plus a complete survey of the

propulsion plant spaces and

neighboring spaces while oprat ing

at various ship s~eds during the

conduct of sea trials.

5.10.2 Measurement E~iment

Sound level measurement and

analysis e~i~ent is avail+le with

suitsble ~ality and capacity to

take measurements rewired by ship’s

apcif icationa. Some sound level

meters are integrally e~ippd with

networks which selectively modify

the signal to provide a fre~ency

reeponse approximating the

sensitivity pattern of the human

ear. Others divide the signal into

octave bands and measure the energy

of each as well as the total. It isimportant to use instruments which

provide data to meet shipbuilding

contract re~irementa.

5 .10.3 Storina Airborne Noise Data

Varioue methods can be

utilized to save data for later

analysis as described above for

vibration measurements.

5 .10.4 Data Collection

The good practices recommended

for vibration measurement are alsopertinent to sound measurement.

5 .10.5 Additional Information

Manufacturer”s instructions

are ade~ate for operating the

e~ipment. Criteria for performance

and selection of acoustical

instruments can be found in the

publications of the Werican

National Standards Institute, Inc.

(ANSI ) which have been prepared

under the direction of the

Acoustical Society of herica.

Alpha-numeric designators of

standards prt inent to acouet ics,

vibration, mechanical shock and

sound recording, begin with the

letter “S”. See references (u) and

(w) for additional information.

5.11 FEEOWATER TESTING

5.11.1 Dissolved OxYaen

Low oxygen content in

feedwatar is an indication of proper

functioning of the deaerating feed

heater. The mount of dissolved

oxygen in the feedwater should be

measured and recorded in the

63

appropriate data sheet in section

5.11.2 Measurement of Dissolved

~

The oxvaen content of

6.

. .feedwater is usually determined by

the Winkler Method as this test is

the most convenient and meet likely

to give the accuracy desired. The

smple must be cooled to a

temperature below 70 degrees F if

accurate results are to be obtained.

A special cooler or cooling coil is

usually provided with the ship’s

feedwater system for this purpose.

Detailed information on how to take

smples and on the test for oxygen

may be found in references (x), (y),

(z) and (aa).

Continuous monitoring of

feedwater oxygen content may be

performed using an electronic

instrument. These instruments are

commercially available, and more

detailed information concerning

capabilities may be obtained from

manufacturers.

5.11.3 Salinity

Low salinity in the condensate

and feedwater is an indication of a

tight syetem, i.e. , free from

in-leakage of sea water. Salinity

should be read at various Pints in

these systems and recorded in the

aPPrOPr iate data sheet in Section 6.

5.11.4 Measurement of Salinity

Sal inity readings may be taken

from the ship’ e salinity indicator.

The salinity indicators should be

checked occasionally against

prepared saples of hewn salinity.

The mercuric nitrate method of

determining salinity described in

the latest edition of reference (x)

is aatiefactory for the analysis of

water from steming boilers and is

also sufficiently accurate forchecking salinity indicators in

evaporator distillate, boiler feed,

and condensate systems “here

readings of 0.25 grain of chloride

per gallon or less may be obtained.

5.12 DENSITY MEASUREMENTS

Density of fuel oil and sea

water can be determined

satisfactorily with suitable

hydrometers except for low API

bunker fuels which solidify at room

temperature. For details see

reference (ab) .

5.13 LEMGE MEASUREMENTS

5.13.1 Measurina Gases

Air and noncondensable gasesdrawn from the condenser by the air

ejector may be measured by means of

an air meter or indicator installed

in the air ejector vent. Three

t~a of this instrument aredescribed below.

5.13.2 Rotometer

One type, a rotometer,

omrates by the flow of gasvertically through a glass tube

which has an increasing cross

section area with a volume flow rate

scale beside it and by a float

which, while suspnded by gas flow,

settles in a psition in the glass

tube at a place indicating the

volwe flow rate on

the scale.

5.13.3 Orif ice-Rotometer

A second t~, an orifice-

rotometer aaeetily o~rates by a

parallel, une~al, split flow of gas

through an orifice and a rotometer.

The inlet of the rotometer is

connected to the gas flow pipe

upstrea of the orifice plate and

the outlet of the rotometer may be

64

connected to the gas flow pipe

downstreu of the orifice plate or

may be vented to atmosphere. The

orifice-rotometer assetily is

designed, sized and calibrated as a

unit for the specific ship system

installation. The scale located

beside the rotometer tube is

calibrated in units of volume flow

rate for the sum of the gas flows

through the orifice and the

rotometer.

“5.13.4 ‘Orifice-Manometer

A third type, an orifice-

monometer assetily, operated by the

flow of gas through in orifice. The

high pressure connection on the

monometer is connected to the gas

flow pipe upstrem of the orifice

plate and the low pressure

connect ion on the monometer may be

connected to the gas flow pipe

downstrea of the orifice plate or

may be vented to atmosphere. The

orifice-monometer assetily is

designed, sized and calibrated as a

unit for the specific ship system

installation. The scale located

beside the monometer tube is

calibrated in units of volume flow

rate.

5.13.5 Ultrasonic Detector

An ultrasonic leakage

detect ion system has been developd

to locate preeeure and vacuum leaks.

Low pressure as well as high

pressure minute leakage can be

detected readily. This system is

sensitive to ultrasonic energy

generated by molecular collisions as

gas escaps from or enters a emall

orifice. Tbe directional probe is

sensitive only to the ultrasonic

fre~ency spctrum by eliminating

audible background noises. Thedetectors electronically convert the

probe output into audible sound in

the attached earphones and drives a

~inter on a meter.

5 .13.6 Additional Information

More details of various modelsand their uses may be obtained from

epipment manufacturers.

5.14 FLUE AND EX~UST-GAS ANALYSES

5.14.1 OrSat Analvzer

For trial purposes,

historically a fre~ently used

instrument for flue-gas analysis is

the Orsat. Basically, all Orsats

are identical in principle; that is,

they all have a nutier of pipettes

containing chemical reagents which

absorb the respective gas

constituent from the smple. The

major difference in the various

commercially available Orsats is in

the design of the pipettes. Some

Orsats have the contact type of

pipette while others use the

bubbling type of pipette.

A contact type of pipette

usually is filled with many small

diaeter glass tubes, rods, or in

some instances, with a fibrous type

of material. The purpose of the

tubes, or rods, is to supply a

maximum of exposed surface to which

the rewired chemical reagent can

adhere. A8 the gas saple enters

the top portion of the pipette, the

reagent is driven from the pipette

into a reservoir. The gas, as it

proceeds to occupy the entire volume

of the pi~tte, passes over the

wetted surface provided by the

filler material.

In the bubbling type of

pi~tte, the gas smple enters the

bottom of the piwtte and the saple

bubbles up through the chemical

reagent. Filler material for

providing exposed absorption surf ace

is not rewired and, conse~ently, a

volume of the reagent e~al to the

unabsorbed volme of the smple is

displaced by the gas. The displaced

65

reagent flows into a reservoir and

remains there until the gas Smple

is returned to the collecting

burette.

A comon type of OrSat is

provided with a measuring burette

and, usually, three pipettes. These

are interconnected by a capillary

manifold and appropriate stopcocks

for routing the gas sample through

the apparatus, The pipettes, when

filled with the proper chemical

reagent, will absorb volumes of

carbon dioxide (C02 ), oxygen (02)

and carbon monozide (CO) .

The following absorbing

reagents are used in the pipettes

C02 pipette - Potassium hydroxide

solution

02 Pipette - Alkaline solution ofpyrogallic acid

CO pipette - Acid solution of

Cuprous chloride

The best results are obtained

when these solutione are prepared

immediately prior to testing. Full

descriptions of the methode for

preparing the solutions are stated

in reference (ad) .

To process a gas saple to

obtain an analysis, a known volume

of flue gas is drawn into the

graduated burette. In successive

operations the gas smple is forcedinto the C02, 02, and CO absorbin9

pi~ttes. Before the saple is

allowed to pass from one pi~tte to

the next it is returned to the

graduated burette. The meaeured

difference in volume, after each

individual gas has been fully

absorbed, is considered as the

mount of that particular gas

present in the flue gas.

The difficulty in obtaining a

represent at ive saple from a

stratified gas strea is the

greatest cause of error in gas

analysis. There is no singlecorrect method of s~pling which is

applicable in all cases. One

method, which results in obtaining

an approximately true smple,

rewires the taking of a nutier of

simultaneous individual smples at

different ~ints in a given plane of

a gas cavity or duct.

Where high-temperature gas

s-pies must be taken it is

customary to use a water-cooled

smpler. This sapler is generally

constructed from materials eimilar

to the ordinary open-end tube,

usually of brass or stainless steel,

used for sapling cool gases, but it

is fitted with a water-cooled

jacket. Water-cooled sapler tubesare superior to refractory tubes

since there is less gas composition

change due to chemical reactions.

Further, refractory tubes are often

brittle and subject to breakage if

impro~rly handled. Thus ,

refractory tubes are usually

inferiOr fOr service and functionalreasons.

A continuous gas saple is

most desirable as it eliminates the

need for purging the smpling lines

of the residue from a smple taken

previously. For this purpose, an

air aspirator generally is used.

For sea trials, continuous temporary

lines should be run from each uptake

through a valved manifold to an air

aepirator powered by the ship’s

compressed air system. The

arrangement of valves should allow a

new ample to be pulled from either

uptake to the Orsat e~iwent for

each saple reading. Two smpling

1inee are necessary when

regenerative ty~ air heaters are

installed; one is connected upstrea

and one downmtrem of the air

heater. Both are needed to

detemine air leakage across the air

heater. The comparative readings

can be used to compute the corrected

stack tem~rature.

66

Lead, glass, or gum-rubber

piping should be used to cOnneCt the

sapling tube to the gas analyzer.

Copper or brass piping also is

satisfactory, but in no case should

ferrous materials be used.

5.14.2 Manual and Automatic TvDes

of Flue Gas Analvzer9

There are a variety of manual

and automatic types of gas analyzers

available as portable or ship

installed e~ipment. These kinds of

instrumentation are valuable for

determining e~ipment performance

and the content of exhaust gaseswhich enEer the environment. see

reference (ac ) for further

information about measuring

particulate matter in a gas strem.

some automatic ty~s of gas

analyzers will indicate percent

oxygen, ~rcent carbon dioxide, net

stack temperature, percent excess

air, carbon monoxide concentration,

particulate matter in the flue gas,

and the percent co~ust ion

efficiency. Instrument

manufacturers need to be consulted

for details regarding gas. s-pling

re~irements and measurement dataavailable on various instruments for

the epecific flue gasee exhausting

from the ship.

The shipbuilder and owner may

agree to use ship installed flue and

exhaust gas analyzers to collect

e~i~ent PKfO~anCe data duringthe conduct of sea trials. The seatrial plan should s~cify the

analyzers to be used, when they are

to be used, and the approved methods

for analyzer calibration.

5.14.3 Additional Information

For more infomat ion see

reference (ad) and contact

manufacturers of e~i~ent.

5.15 STEW QUALITY AND PURITY

~ASU~~NTS

Measurement of entrained water

droplets (qality ) and entrained

solids (purity) in stem is not

comonly rewired during sea trials.

However, sapling techni~es and

measurement devices are discussed in

reference (ae) .

5.16 VISCOSITY ~ASUREMENTS

The measurement of viscosity

is not comonly rewired during sea

trials. The viscosity of fuels for

the propulsion plant or auxiliaries,

or for cargo may be necessary to

resolve problems during sea trials.

For measurement information see

reference (af) .

5.17 ELECTRICAL ~ASU~MENTS

5.17.1 Measurina Oevices

For ships with alternating

current, a portable analyzer

e~ipped with an weter, voltmeter,

power-factor indicator meter and

kilowatt meter will be useful.

Isolated usage of the meters is also

~seible. For most A.C. motor

installations the input current is

sufficiently reliable for indicating

the motor load. A ~rtable

tong-type meter will be found

satisfactory for measuring the motor

current. Since this meter clmps

around the cable one phase at a time

and does not have to be ineerted in

the circuit, it is more convenient

to use than the analyzer for this

application. A prtable poly-phase

watt-meter may be installed to

aseure accurate measurement of

generator loads.

5.17.2 Calibration

Recently calibrated shipboard

electrical instruments ehould be

sufficiently accurate for all uses

67

except special performance tests.

Before sea trials they should be

carefully inspected for signs of

dmage, and the due dates for the

next calibration should be following

the completion of eea triale.

5.17.3 Additional Information

Electrical measuring

instruments and testing apparatus

are covered in detail by reference

(k).

5.18 WIND SPEED AND DIRSCTION

~ASURSMNTS

5.18.1 CUD Anemometer

Wind speed is measured usually

by a cup anemometer which gives

aPParent or relative wind speed.

Apparent wind speed occurs bycotiining ship, s velocity and true

wind velocity. Any instrument which

measures wind speed may be used to

measure apparent wind speed.

5.18.2 Indicators

One type of indicator flashes

a light every time one-sixtieth of a

nautical mile of wind passes the

transmitter. The ntier of flashes

per minute is the apparent wind

speed in knote. An electric counter

can be connected in the flasher

circuit and controlled by an

observer on the bridge to state the

distance traveled during

standardization runs. .The average

aPParent wind spsed is obtained bydividing the counter reading by the

elapsed time across the course.

Another ty~ of instrment indicates

aPParent wind roped instantaneouslyand continuously and re~ires no

timing. This type of indicator is

recommended because of the

convenience in obtaining readings

from it.

5.18.3 Sir= Anemometer

The Sirm type of anemometer

has a register which records linear

feet when a gear train is engaged.

The register can be zeroed after

reading it. Velocity in feet per

minute is obtained by dividing the

register reading by the elapsed time

in minutes. Each instrument

rewires individual calibration. It

is important that the anemometer

face s~arely into the air strem

and that average readings are

obtained. For best results, the

dimeter of the air strem should be

several times the diaeter of the

anemometer.

Care should be taken to ensure

that the motor bearings are kept

clean and free from lint, dirt, or

grease, because a lack of

cleanliness will cauee friction or

drag and seriously affect the

accuracy of the readings.

5.18.4 Oirect-Readina Anemometer

The direct-reading anemometer

has a varied rotor and a dial which

reads in feet per minute. The Sme

precautions stated above for the

Bira typ, apply to the direct-

reading anemometer.

5.18.5 Deflecting-Vane Anemometer

The deflecting-vane type of

anemometer indicates air velocity

directly in feet per minute. This

type of instr~ent is very useful instudying air currents in staterooms

and meaauring pak velocities.

Other ty~e of instruments, such as

the heated thermocouple, the

velometer, and the hot-wire

anemometer may be ueed where the

accuracy of such instruments is

sufficient. They rewire fre~ent

68

calibration and are of little use as

a wind speed measuring instrument

for standardization trials.

5.18.6 Wind Direction Indicator

A wind-direction indicating

system, which continuously indicates

the apparent wind direction relative

to the ship, is recommended for sea

trials. This system will consist of

a remote transmitter and an

indicating unit.

5.18.7 Combination Indicators

Cofiination wind indicators

are available. They cotiine

readings of direction and speed, and

they are more convenient for sea

trial purposes than the separate

indicators. They utilize a contact

type synchro transmitter to transmitwind speed and direction to a dial

readout.

5.18. a Locat ina Sensors

The sensors for all wind

direction and velocity measuring

e~ iPment should be located highenough above the ship’s etructure so

it will receive an unobstructed wind

flow and not be subject to wind

currents and eddies from any nearby

object.

5.19 RADIO~TRIC T~CKING SYSTEMS

5.19.1 Tvues of Devices

‘A nutier of electronic

position location systems are

available commercially for use in

conducting standardization and

maneuvering trials. hong these

systems are: Raydist, LORAN, Decca,

and Cubic. These eysteme, with the

exception of Cubic, o~rate on the

basic principle of measuring the

half wave lengths” of two continuous

radio waves transmitted at different

fre~enc iea. Cubic oprates on the

basic principle of meaeuring the

phase delay of t“o signals.

5.19.2 PrinciDle of Meas”rinq Half

Wave Lenuths

A typical system consists of

two portable transmitters, located a

known distance apart on shore, and a

shipboard receiving station.

Included in the shipboard station is

the “lane counter” which indicates

the lane count, i.e. , the number of

half wave lengths from each shore

station to the ship. By knowing the

distance between lanes which iscalculated for the frequencies in

use and based on the empirically

accepted velocity of propagation,

the lane counter readings can be

converted to distancee.

The position of the ship canbe determined mathematically at any

time using the two shore radio wave

transmitters and the ship to form a

triangular relationship to one

another. A1l three distances are

inputted into a mathematical

fomula, and the ship” s location is

the solution. The dietance between

the shore located transmitters is

constant during the sea trials. The

changing lane count between the ship

and the two transmitters is inputted

to the mathematical formula at any

instant in time that one wishes to

know the ship’s location.

In addition to the lane

counter read-out, the typical

shipboard inst rumentat ion may

include additional e~i~ent such as

a strip chart recorder from which

fractional parts of a lane can be

derived at a given instant, and a

plotter which records the path of a

ship during maneuvers.

If the absolute ~sition is

rewired, the lane counters must be

set by means of premeasured range

marks or by flyover of an airplane

69

ewipped with a duplicate of theship, s radiometric e~ipment. Also,

lane counters must be thus reset if

the lane count is loet by power or

e~ipment failure, maloperation or asevere electrical storm. HOweveS,

even without a correct lane count,

these system5 are able to detemine

distance and direction traveled

during selected time intervals, for

speed determination or for plotting

the ship’s path during maneuvering

tests.

5. 19.3 Principle of Measurina Phase

~

The Cubic Autotape system

operates on the principle that a

modulated electromagnetic wave

propagated through space undergoes a

phase shift that is proportional to

both the distance traveled and the

modulation fre~ency. The system

consists of a two-range interrogator

inetalled on the ship and two

portable respnders located a known

distance apart on shore. It

computes range by measuring the

phaee delay experienced by the

modulation signal during its travel

from the interrogator to the

responder and back. The

interrogator automatically displays

the ranges between the ship and the

shore stations simultaneously at one

second intervals. If a prmanent

record is desired, a printer can be

connected to the read-out

instrument.

5.19.4 Siahtina Land Fixes

During sea trial planning the

customer and the shipbuilder may

determine that radiometric syateme

are not necessary or sufficiently

convenient. The met hod of sighting

preplanned land fixes during the

conduct of maneuvering and

standardization trials continues to

be an acceptable practice for come

sea trials.

5.20.1 TvDes of Instruments

The following types of timing

instruments may be used for trial

data:

(a) Ship’s Clocke

(b) Stop Watches

(c) Electric Timers and

Clocks

(d) Chronographs

A detailed description of each

of the above instruments is stated

in reference (ag) .

5.20.2 Svnchronizina Clocks

Ship’s clocks may be used to

time events. Prior to departure,

the master clock should be 8et to

the correct time and secondary units

synchronized with the master. Time

pieces furnished for trials should

be synchronized with the ship’ s

system to avoid disagreement in

report ing events.

5.20.3 StoD Watches

Stop watches most suitable for

sea trial data are electronic

watches and ttiers. These watches

and timers are battery pwered. All

stop watches ehould be checked

against a time piece of known

accuracy before the trials begin.

The cotiined stop watch and time

piece ehould be adjusted and

re~lated so that it does not gain

or lose more than thirty seconds

over a twenty-four hours period.

5.20.4 Electric Timers and Clocks

Electric ttiers may have a

synchronous motor drive and dependupan the ship- s ~wer fre~ency fOr

70

accuracy. Electric stop clocks with timers may replace electric timers

accuracy

crystals

readable

second.

designed

They may

accuracy

controlled by quartz to maintain standard item, if

are available with dials shipboard power frequency is not

to one one-hundredth of a constant or is uncertain.

Special timers may be

and used where desirable. 5.20.5 Recorders

have a master clock with

controlled by a qartz Recording instruments should

crystal design. When electric time be inspected regularly to see that

measuring devices dependent on the paper-driving mechanism and

ship’s power are used for sea paper marking device operate

trials, caution should be exercised properly to provide correct time

to maintain ship’s generator indications.

fre~ency at 60 CPS. Electronic

71

6.0 TRIAL DATA AND ~PORT

6.1 GENEW

A trial report should be

prepared by the shipbuilder and

delivered to the owner and others as

specified or within sixty days after

the completion of trials. The

reprt should present the trial

results, relate them to

re~irements, and should contain all

data and information needed to

evaluate the results rewrted.

This section provides smple

formats for identifying the ship and

its major characteristics and

reporting data for the tests and

trials covered in Sections 2, 3 and

4. In some cases the data are

reported directly as taken, in

others one or more reductions are

re~ired to reach the value to be

reported in either tabular or

graphic forms. Copies of raw data

sheets, if legible and

interpretable, may be used for

directly reprted data. Raw data

need not be supplied for values

reprted in reduced fore, but

supprting data for such values

should be retained and held

available for the owners or

other acceptance authorities for the

life of the contract.

Data fores are included for

all trials and tests for which

procedures are provided by the wide

regardless of contract re~irement

for such a trial or test. Inclusion

of the data sheet should not be

conetrued to rewire that a teat or

trial be performed.

Similarly, data sheets list

all data pertinent to the test or

trial of a typical plant or system

or e~ipment. A particular ship may

not have an instrument or gage to

provide a data item, or might not be

designed to include the component or

aPPaKatu S to which the datapertains. Guide data sheets, thus,should be taken as a recommendation

rather than an absolute re~irement,

and data not included on the data

sheets but available and pertinent

should be included in the report.

Also, the presence of a data item

does not constitute a retirement to

install special instrumentation to

provide it. Such re~irements are

imposed by the section of the guide

rewiring the test or trial.

Critical data as defined by Figures

la, I.b, and 1.c should be

instrumented to the extent re~ired

to provide confidence in the

results.

6.2 DATA Pm

Since the Guide is for general

application it cannot COVer with

precision the particular contractual

or technical circumstances of a

particular ship or clase of ship.

It is imprtant therefore, as set

forth in Section 1, for theshipbuilder to study the guide, the

contract, and the ship’ s apcifi-

cations, and prepare a data plan.

Thie plan should include data fores

suited to the location and function

of the instruments to be read, a

system for transmitting raw

~rfomance data to a central

computing station for processing and

72

a Pr0ce9s fOr making data availableto authorized parties aboardship.

Data forms should distinguish

between data from special sea trial

instruments and data from ship’s

instruments.

6.3 DATA C~W TRAINING

AS Section 1 states in general

terns, the data crew should be

trained in advance of trials in the

use and location of the instruments

to be read, the corrections to be

applied, and the calculations to bemade. Training should include

familiarization with the data forms

so that entries will be made in the

correct column, and the instrumen-tation for data items which ehould

be read on the mark of the data

interval. The mark is provided by

the sea trial signal system.

6.4 MANE~RING TRIALS AND SPECIAL

TESTS

Figures 5 through 19 have been

developd to assist the shipbuilder

in preparing data tabulat ion sheets

and in reporting results prtinent

to maneuvering trials and s~cial

tests. All of the data re~irements

of the various trial events are

provided by the figures. Plots of

the data associated with Fi~res 5

through 13 should be provided to

indicate smoothness of data.

Results of the “Z“ Maneuver

and epiral maneuver tests ehould be

plotted. If radiometric eyipent

is used during the trials, the

resultant plots of the ship’s track

during turning circle tests and

wick engine reversals should be

included in the trial reprt. Plots

of turning circles should be

corrected for drift by the method

explained in Appendix A to Chapter

6.0. When precise tracking is not

avail sble, plote of the radar wake

return may be made and included in

the report. Such plots areindicative rather than definitive of

the ship, s turning characteristics

and need not be corrected for drift.

6.5 STANDARDIZATION TRIALS

Figure 21 has bee” developed

to assist the shipbuilder in

reporting results pertinent to

standardization trials. A1l of the

data requirements of the trial event

are included therein.

6.6 FUEL ECONOMY, ENDUNCE , BOILER

O~RLOAD AND STEM RATE TESTS

Figures 22, 23 and 24 have

been developed to assist the

shipbuilder in reporting results

pertinent to main propulsion fuel

economy tests. The figures

presented are representative of a

tYPiCal stem Pwered ship, diesel~wered ship, and turbine powered

ship. Other types of main

propulsion plants and variations of

plant e~ipment and systems will

rewire appropriate modifications.

Figure 25 has been developed

to assist the shipbuilder in

report ing results ~rt inent to the

main propulsion turbine stem rate

test.

6.7 PROPULSION PLANT TRIMS

Performance data is reprted

to supprt the results of the

propulsion plant trials, to assist

in interpreting these resulte, and

to provide baseline reference data

for oprating praonnel once the

ship enters service. If specific

data is ~rtinent but not available,

a note to this effect should be

included on the applicable data

sheets.

Recorded data for the test

runs should be averaged, with

73

obviously erroneous readings

re jetted. If recalibration of

ship, s instrumentation is

accomplished prior to ship delivery,

note of such recalibration should be

included on the applicable data

eheets.

Figure 26 reflects the

recommended content for reporting

operating data for a typical stea

turbine powered ship and main

..propulsion diesel and gas turbine

installation. Resulte of the boiler

overload test should be performed as

indicated in the boiler section.

6,8 TRI= ~PORT

The contractor should prepare

a trial report with recommended

content as follows:

6.8.1 Introduct ion

The introduction should

include the contract nutier, hull

nutier, omer designation, ship’ s

rime, principal dates, contractual

parties and construction contract

references, preceded by a photograph

of the ship or a sister ship

underway, if rewired by the

contract.

6.8.2 Shim’ s Characteristics

(a) Type of ship

Exaple: Single- 6crew,

stem-turbine

driven,

cotiinat ion bulk

and general cargo

ship.

(b) Principal Characteristics

(1) Length overal 1

(2) Length between

pr~ndiculars

(3) Bea, maximum molded

(4) Depth to main deck at

eide, minimum molded

(5) Draft, full load, molded

(6)

(7)

(8)

(9)

(lo)

(11)

(12)

(13)

(14)

Displacement at full

load draft

Gross tonnage

(approximate)

Net tonnage

(approximate)

Draft, maximum ballast

provided by ship system

Horse~wer

Sustained sea speed at

full load draft and

registered horsepower

Estimated fuel

consumption at sea (bbls

per day) at registered

horsepower

Estimated fuel

consumption in port

(bbls per day)

Endurance in nautical

miles at sustained sea

speed with a record of

fuel consumed.

(c) Complement

(1) Officers and crew

(2) Passengers

(d) Deadweight and displacement*

(1) Light ship

(2) Fuel oil

(3) Fresh water

(4) General cargo

(5) Refrigerated cargo

(6) Liw id cargo

(7) Total cargo deadweight

(8) Tot al deadweight at ful 1

load draft

(e) Capacit ice*

(1) General cargo bale cubic

(2) Refrigerated cargo net

cubic

(3) Convert ible 1i~ id cargo

net cubic

(4) Non-convertible li~id

cargo net cubic

● May req ire additional

breakdown dependent on

ty~ of cargo carried.

74

(f)

(9)

(h)

(i)

Hull characteristics

(1) Prismatic coefficient

(2) Midship coefficient

(3) Bulk as percent of

underwater profile area

at full load draft

(4) Type of bow

(5) Type of stern

Rudder characteristics

(1) Nutier and type

(2) Rudder aB ~rcent of

underwater lateral

profile area at full

load draft

Propeller characteristics*

(1)

(2)

(3)

(4)

(5)

(6)

●

TY@ including directionof ahead rotation and

nutier of blades

Dimeter

Pitch

Expanded area ratio

RPM at full load draft

and registered

horsepower

Des ign submergence

Include data for each

propeller

EW i~ent identification data

(1) Main propulsion

machinery

(2 ) Imprtant auxiliaries

(3) Other e~ipent as

s~cif ied. It iS

recommended that, as a

general rule, s~cial

andjor uni~e e~i~ent

be listed with

identification data.

6.B.3 Trial Data

(a) Log of evente.

(b) Principal personnel present on

trials, including

representatives of the owner,

acceptance authorities,

regulator bodies and

shipbuilder.

(c) Trial ballast schedule.

(d) Trial results:

(1) Maneuvering trials and

special tests. See

Figures 5 through 20.

(2) Standardization trials.

See Figure 21.

(3) Fuel economy tests. See

Figures 22, 23, and 24.(4) Stem rate test. See

Figure 25.

(5) Propulsion plant data.

See Figure 26.

6.S.4 Other Data

(a) Nufier of days between sea

trials and meet recent

drydocking.

(b) Wind direction and velocity.

(c) Sea etate.

6.8.5 ADDendices - As Elected

(a)

(b)

(c)

(d)

(e)

(f)

Design heat balance system

diagrms.

Fuel oil analysis re~rt.

Flometer calibration curves.

Fuel and stem rate correction

curves.

General arrangement plans if

they are availsble in reduced

size on a single sheet.

Other available information

prtinent to trials.

75

——Astern 7A“x, l$. rq

Sh tip N.me &head Steering Steerlnq Steerlnq

Unit unit Unit (If Dem -

Triel Date [P or SI (P or s] [P., s) ons Lra Ledl

Tlma O( Test

Baea Course

Depth of Wa tar

Sea COnditl. n

Wind Direction

Wind Velocity

Trial Dr art [F. dl

Tr]ul Draft (Aft)

P.opel!e. RPM(B. qinnlnq I

Propeller RPM (End)

St09rlnq Station inControl

Rudd.. Movement Tim. O-R O -L O -R a

(s,. ,)b R-L L -R R -L

L -R R -L L -R

R -o L -O R -O

Maximum Rudder O -R O -L O -R a

A“qles R -L L -R R -L

L -R R -L L -R

O -R O -L o -RMax. Steady Motor

R -L L -R R-LAmps

L -R R -L L -R

R -O L -O R-o

Maximum Ram Preeaure

Max. SOrv O Preee.(If Avoilabl.1Ma. . Repl en. Press.(If Available)

Max. Pump Stroke(If Available)

Idle Volta

Idl@ Amps

Idlo RPM

Minimum Motor Volta

> R.ddar a.qlas and .“dd.. mov. msnt tlmem a. dmmonstrat. d. lime to s.. ”..no. mal otearlnq mods and to activate emerqancg unit also to be recorded.

b Time from start to 5 d.grees b. fare orderad anqle

FIG. s Steering Tests

76

!.. 1s..

— “... UtPARl” RE FRU” .ASE 1K6CK

— ,AC71C, L 0,..ETER

OF MEAOINQ

— FINAL o] Auslsn

lN1ll AIE

—z— 4

I,.,,,,..,,.,,,,.....as ..*,.,. ,.., ”, . ...”..,

,,,, . . ,.,.,., . . . ,.”a, ” ,.,,,.,.. ,, ,.,,.,OP.. I*I...1 ..di... h.h. .“*.. ”..s,,, . . . . . . . ., ,,..,,,

M.,. ! ,!., d.” b. ., ,,,,. ? CO., .“,. ””.,.,,,,. ” .,,, .0,,.,.,,,. ..,...’,...

H.. d,”q <...B... C.. ?,.

500 1000-

SC4LE IN FEE1

ship N,..

T.. t D.t.11.. T., t S.9. ”

B,, * c.”,,,

R.dd. ? A“*I*

Ehaft RPM 10. qlnnl”q )

Eh, rt RPM [End I

D,Pth ,1 W,t. r

e., C.”4L %1..

wind 01,. cti. n

Vina V.l. clt”

1,1.1 O.afl (Fvol

NOIE: R. Pr.,, ”t.ll. ” .1 th, .hl P1.1.1 0.. ?1 [UT)

.h. uld b. , 11.. .c. l.d 1“ I.”eib, U.,.”. D.,lt C. . . ..l ..”

.P1. nt. d 1. .nd I..,l. d .“ tb. .1.010:::hb:h~:L:,:~ y.: ,.lO.,. ”CO i,.. k

01.1, 01. .

lqP. .I Tra.ki.q 8*.1..:

FIG .

Radiometric or

u,. . O,p,, tvr, f... 8,.. c.....

DrlrtC.rr. ct lo”: :fi:ct le._

~ Turning Circle Test

Other Precise Tracking Available

77

r -,AC, ,CAL .,*.E, F”_

TRANSFERi

I

IeO” CHAUOEOF HEADINO

::

:-— FINAL DIAGIER

Sae 1080-

SCALE IN FEE1

Vl”d Direct ]..JmV1nd V.locltu

T,lal O-aft {FVD1

1,1.1 Draft lAFT1

Adva... to Chang. Hdq. 90”

T.an. f,r i. Cheng. Hd9. 90”

Tactl. al D1. m.t,,

Fl”al Dlamel, r

FIG. 1 Turning Circle Test

Radiometric or Other Precise Tracking Not Available

78

tWIND

BASE COURSE

(5), \

i..-. . . .

. .

/

>

~OU COURSE

PE

\

~:

----~.-(-z )

../-,---

5 10 15

OECRCES

Lf n I RCfl

HRtider Elap-d mm

Mwment (w)

(1) Stud 10RAft.in 10R

..(2) Stofi 10LMain 10L

(3) stad 10Re“ 10R

(4) Stan IOL

(5) Attain O

10

Em. Tent Beq.n

Base co”...

Rudder tigle

Shaft RPM (Beginning)

Shaft RPM (End)

Oe,th of Woter

mElapsed fima

(s..) Hdq.

FIG. ~ “Z” Maneuver Test

79

Sea Condition

Wind Di.ectfo” I

~ ‘raorari ‘Aft)

Trial Draft [Fwdl

Time

?udder Anqle —

lapsed Time [See)

Time

ieadlnq

FIG. ~ Initial ~rning Test

80

STABLE SHIP

R“DDER RETuRNEDTO MIDSHIPS

*

- ‘1UNSTABLE SHIP

Im (s.0)

I

“..dl”g t,.mh.. co”,,. Svad (K!.) RPM

FIG. ~ Pullout Test

81

(

Ship NameI

PORT STARBOARD

RUDDER ANGLE

la) STABLE SHIP

<.0 ?

R“dde. Anqle

Sheft RPM (Beqln. ing)

Shaft RPM [End)

I DeDLh of water I

ISea Condlt!on

Wind Oiroct [on i

! Wind Veloci Lu I

*-t

1. 1.1 Ora Ft [Fwd)

T,lal Or aft (Aft]

+1’PORT I I SIARBOARO

Oata for Step No. R“ddar Angle

Time Ship Change ]“(s.. .) Headinq Ship Headinq

Constant for6 Conaec. tiveRoadlnqs

Notes:

A total of 6 reading8 or constant rateof heading change 1s ne. ded to cal.. lataaverage rate in Deq. /Sec.Thiu calculation 18 done for each stop.

Q“dderA“qle

?@RlSR18R

5R3RlR0

::5L

lBL15L

28LISL18L

5L3LlLe

::5R

10R15R

2@R

Conslant Rateof Chanqe

!. Ship Ho bdinq(0. q ./see .1

FIG. Q Spiral Test

B2

-e. @ -

*

/----,,

,’ STABLE( ‘SHIP

~.~.

. .

‘\

i

.’<_u NsT4BLE--

----SHIP

I I Illea )0 0 10 ea

PORT RuDDER ANOLC STARBOARD

I Ship . . . . ITent 0.1.

Tim, 1..1 B,q, n

B.,, course

D.plh of Wal,,

S,a condition

I Wind ,1?..1,.. IWl”d V.lo. ]t”

TFlal Or, fl {F. d)

I Trial Oralt (4f11 I

YAV RATESTEP OEQ/SEC

RuDDER ANQLE

1 1.9R

e a .BR

3 e ,6R

4 0 .4R

5 0 .*R

b e.l K

7 0 ,OR

8 8,1L

9 0 .EL

10 0 .4L

II 0 ,6L

Ie 9.BL

!3 1.@L

FIG. u Reverse Spiral Test

Shl P Name 1,1* I Date

Time O{ Test W]”d 01? 8.11..

Ease Course Wind Velocitg

Depth of Water Trial Draft [F. dl

sea Condltl. n Trial Draft [Aft]

Thr. et,. Name

,. s... ,. S., . . ..”..”.,, .,,,. . . . ,----- . ..3

Iap, ad Time0 Knot, 3 Knot. 6 Knots

[Ml” 8 Sec ) Thruster Th, ”,ter & R“dde. Only Th, ”eter &Onlq Full Rudder Full Rudder

Rudde. Onlq

Ch. nq. Chang. Change Change Ch. nqaHdq

1. Hdg Hdg in Hdq Hdq I. Hdg Hd q i“ Hdg Hdg

@

1“ Hdq

0“ 00 0“ 0“ 00

10

20

,3BI 1 t , I

a 3@0 Left 3a0 Left 30° Le<t 38° Lar L 30” L,<!

1 1 ?

~o @“ 0“ 0“ 0“

1

NOTES :1, Ship 1s 10 b. headlnq Into the wind .1 tha b.qinninq of each 1..1.2, 1; .Iapnad time reaches 10 minutes prior to 30° change 1. ship

h.adi”q. t.rminat. the test at this point.3. If Thru8ter IS .ffective at 6 knots. ahlp 8P.. d 1s Lo b. increased

at 3-knot Intervals until thr”ate. 18 no longer effective.

a Reve.8e Thru8ta. .ndler Shift Rudder

FIG. u Thruster Test

g4

Ahead to Aster” IShip Name Trial Date

Time to Test Time to Start Shaft Aster.

Ease Co. ree Time to Ordered RPM Astern

Shaft RPM IBeginnlngl Time to Stop Ship

Depth of Water Ahead Reach

Sea Condltlon I IWind Direction

Wind Velocity

Trial Draft [Fwd)

Trial Draft (Aft) 1

NOTE : Also to be ,ncl”ded are max L-mum excursions of RPM, torque, steams“pplq, turbine Inter”al and exhe”gtpressures and temperatures, orequivalent data for diesel o. qasL“rbine plants, at ?requent inter-vals d“rlnq maneuver.

Fl”al Heading

Marker

I234

Elapsed Timo Distance Traveled C“m”latlve Distance[Mln and See) Between Markers [Feet) Traveled [Feet)

Substitute plot of ship”8 track if radlometrlc equipment is inuse.

IAstern to Ahead

Time of Test Trial Oraft [Fwdl

Bass Course Trial Oraft [Aft]

Shaft RPM {Bag innlngl Final Heading

Oepth of Water Time to Start Shaft Ahead

Sea Condltlon Time to Ordernd RPM Ahead

Wind Oirectlon Time to Stop Ship

Wind Valoclty Maximum RPM AhOad

Torque (If Available)

FIG. ~ Quick Reversal Test

B5

Ship Name

Trial Date

Time or leBt

Sha?t RPM 16K)

[SK )

14K)

[3K)

Dep Lh OF Water

Sea Condition

Wl”d Direction

Wl”d Veloc!ty

Trial Draft (Fw6)

Trial Draft (Af L)

Ruddev Eldp%ed Time (Ssc)

Anqle 6K 5K 4K 3K

Start 19R

Attain 10R”

Start 10L

Attain 10La

Star L 0

Attdln eb

Start 35R

Attain 35Ra

Start 35L

At Lain 35La

Stat 0

Attain E

Rudder Max, Depar t”.. $rom Ease course

Angle 6K SK 4K 3K——

10R I I II I I

35R t –-m1 !

10L

35L I I

a. Rudder angle is to be held for 30 seconds beforestarting next rudder movemmnt.

b: Shig speed la to be rneiored prior to eta. ti. q tho35 rudder movoments.

c. Teat 1s to be cant lnuod 1. dacrea. ing l-knot ln -tervale until the rudder 1s no longer effective.

FIG. ~ Low Speed Controllability Maneuver Tests

86

1. I II SIIIP Name Trial! Uate

Time of Test

Sea Condition

Wind Dlrnct [on

I Trial Draft (FWD) I

I Minimum Steady Shaft RPM I

FIG. ~ Slow Steaming Ability

Ship Name Trial Date Time Began

Time to holut each anchor separately frOMThe raq” ired initial depth

Averaqe chain speed In feet per minute

Time to ho let slmultaneoualy both anchorsfrom the required Initial dual hoistposltlon to water edge

Averaae chain speed In feet per minute I I

Chain 8 topped by hand brake at followingdepths [fathoms]

=

1

{I I

Maximum Readings as Peri inant Water Depth (fathoms)

volts Required Initial Depth(one anchor)

AmpsRequired Inttal Depth

(two anchors)Steam or Hyd. Pres8

NOTE: Unusual occurrences. if any, are to be reco? dad.

FIG. ~ hchor Windlass Tests

DISTILLING PLANT TESTS

Users should develop their Own format for reporting the results of this

test, depending upon the e~ipment available. However, the following

information should be recorded from the ship’s instruments for each distilling

plant.

Prior to demonstrating distilling plant performance check safety and

control devices including:

Operation of Alarms

Operation of Dump Valves

Operation of Bromination System or

other chemical treatment system

The following data should be recorded every 1/4 hour or 1/2 hour as

determined by the customer with the shipbuilder when demonstrating the

performance of each distilling plant:

Stem source (Live Stem/Bleed)

Distiller Stea Supply PreS8ure

Air Ejection Stem Supply Pressure

Salt Water

Salt Water Injection Temperature and Preseure

Feed Temperature and Pressure

Feed Heater Shell Temperature and Pressure

Feed Pump Discharge Preesure

Brine Pump Discharge Pressure

Chemical Proportioning Pmp Discharge Pressure

Distillate

Distillate Temperature

Salinities from Installed Sensors

Gallons of AcceptAle Distillate

Capacity (GPD)

Design

Test

Duration of Test

Distillate Pmp Discharge Pressure

Condenser Shell TW~rature and Vacum

Distiller Stage(s) Temperature(s) and. Pressure(s)

NOTE S :

1. The above data list should be adapted for the typ of distilling

plant installed.

2. The data from the tiove list for a 4 or 6 hour period should be

evaluated by the customer and the shipbuilder to detemine whether

the distilling plant ~rfomance was satisfactory.

FIG. ~ Distilling Plant Tests

88

Ship Name lT.ial Date I

Mode of Positioning

Up Oration

Time StartI I

Time Complete

Ship Location I I IOepth of Water

Sea Conditfon

W1”d D1. ectio” I I IWl”d Velocity I I I

Tide/ C”r. ent O1rectio.

Tldo /Currant Voloclty

Ship6 Headl”g I I IShlpe Speed

Shaft RPM I {I 1

PPo Deller Pitch IRudder A“qla I I IThr”ster{el Force

Thruster(s) D1. eetio”

Loq of Operations and

Fe at.,., Oemo”stratod I I I

FIG. B Dyn-ic Positioning Sy6tm Tests

89

SR, P N... Tr, al 0.1. SL. rt 11..

sea stat, Shl PS H.edi”g AI. Tempe. al”re OF/° C

centralized control U.ne. vers I Po, llio” Shari RPM

O.de. ed Respona. 11..[s.. )

Stop to Maxlm”m Ahead [etoppl”q .1 each I.an. ”.evlnq @peed p.8it10”1

II

I I

uaxlm”m Ahead to Slop (slop pinq al each Imane” ve. lnq Epeod posit ionl

1

I

9top 1. Maximum Amt. r. lstopping .1 each Imane. vo. !nq 8Pe4d posit lonl

I

I

I IOu!ck Revocsal f... Maximum Ahead to

Marlm”m A. Lern

O.lck R.ver8al f,.. Maxim”. Aate. n 1.Maxlm”m Ahead

Ma. lm. m Ah., d to Stop i

O1h. r Ma”e”v., s (as soaclfl. dl

.“,, s ,,.”,..1, Po.lt l.”. ordered may be 1. ie. m. .< RPM .ath. r than Lel. qraph

posltlo”.e. Rep. rt .nq act”ati. n o< .1., ”. and safetg d.v ice.,3. R.o. rt . . . burner f!om.. ut. and . . ..11. <..1... comb. et ion

control p-erformanca.4. Rmport axe. ralona in plant condlt lone e“ch aa bollar water

Iev, l, stream P.*saure. sleam dump lnq. .1. .S. Th. shaft RPM r.. pen.. tire. {S..1 data .. 1”.. i. ..1 e“itebl.

r.r a ship flttod With a Constanl qp.. d. controllable pitchP.. P* II...

6. The destqn of this form end the data c.ll. ctl. n sqatem shouldb. Lail... d 1. p.ovld. m.anlngt. l Lnto. mail. n baaed on th.P.rf. rmenc. SP. ciflcat ions for th. tqp. of control .q. t.m andthe Lyp, of P, OPUI.1O. .q,l. m ln,l. tl, d.

FIG. Q Centralized Control System Tests

90

1.,.1 Dat. w,, ,, T.mp,. at...

1,,.1 0,.(1 (F. dl 8.1.. D.., ttq

1,1.1 0,,(< [Afll

S1ANDARD1ZA11ON RE5u LTS

6,,, d ~u” A;~pa I ~,v; :::; o”,P., ., ,s::.4 “:!::’ Rpu K..,,

I

1 2

h“ g

1

11 e

A. q

1

TRIAL COND[11ONS I

. . . . . Ti., .1 V!nd !R.. 1.*L H*ad1n9 . . . ,“, . )M. ,

. .

. . . . . w,”., I Et, CUrr. nt V. L,.P., nt

. -.. .,.. !qht 01. , v,!. DIP. O.pth

[E.,, .t, d [E,,,. t.dsi [F... ~@bl*.1 ‘

I

I I I I I

1 1 1 1 1 ! , I ,I 1

IllI I I I I I I I I

111 ~

I I I I I I I I

1 I I I I I I I I I Ii

NOIES: 1.

e,3.

R.co.6 4ai. f.. .ddlt,. n.l .v..6 PO1”l. a. .ddltio”al run. ● t . ql.. ”.p.. d Pelni h.” aoplloab l*.

::::: /~.;::.: n:n69**d/RPM .“r”** *ho” Id 8. app. nd. d t. Lhla fig.., ._F1/n.. ti., 1 .11. .

TYP. .f r..9* u*. d

FIG. ~ Standardization Trials

91

Ship Nom. 1,;.! Dtia

fire. of Teat -blent d, 1.mP.

Duration of T=( Relative H.mitily

~A..,w Sholt Hwsep.w.r (SHP)

fuel Consumptrnn

M,.sur,d Flo. O(G.l. /Hr.)

SP={NC C,.vity 0 60° Fb

Fuel %1 Tempr.ture at Meter

Specific C,ovity at Meter

r..) 0,1 D.”sity (w.uNV.flOL,) at M.1.,

Fuel Cons.mptim (w, UNIT. /Hr.)

Fuel Rate (W. UN~./SHP-Hr. )

fuel Rat. Corr=tion for Fwl U.d’

tigher H.tii~ vo#ue-Hwb(m.w.uNm]

C.;recti.. Fac*Or (or Heat Avo!loble

Co;r.cl.d Fwl Rot. (W. UNV/SH? -Hr.)

FIG. 2 stem Propulsion Plant Economy Test

92

I 5,,[0 “..,;;. “-”-” ‘–’—–– ‘“-””--–T;,;:;”;-—––——”” “– ““–”–”-‘-–””–”

T;me 0, ,.,, mb;.nt firlamp.

Our*ion .1 1..1 R. Lativ. ..midlty

~Avwoge Shofi H. MPOWO, (SHP)

Fuel consumption I

‘“’’’’’’””’’”’”’”’-Fud 0!1 D.n*ily (w. UNIT.flOL) .1 M.t.r

F“.I cm..mpfi.. (w.uNI1 ./H,.)

FU.I Rat. (n.uNfl./sHp-H,.)

F.* I Rot. br,.clrn” for r..l u-d c

High.r H.oflng V.1”.-HW b (B~.W.UNn)

Cov..tio. Factor 1.7 Hem Available

c.rr.ct.d FU.I R.t. (W.uN17/sHp-Hr. )

Fuel Rob C.m,Ction, 1., mm.&P. fl.ms tr.m D.s19n Co”dftlonsc T,* I Desig. rtif. Fa.lor Correctbn

hbl.nt tic Tempwatur. ( ‘F)

mbrnnt #r Pr.-.re t,HG)

%dt sped (RPM)

Eqine sp~d (RpM)

Cenemlor L~d (W)

D1.tilllq P1..t L.ti [CPD)

Ship Semi.. St-m

1.1.1 mm=kl~

FIG. ~ Diesel Propulsion Plant Economy Test

23

] O“roti.”.1 Test I Relative H.miditv I

FIG. ~ Gas Turbine Plant

94

Economy Test

u.. c.red FI.. o (GOI./Hr, )

Specific Cravily 0 600 F b

ruel 0,1 l.m~roluro at Mete,

Specific Cr.vity at Met.,

Fuel al O.n,tiy (m.uNr,fiOL. ) mt M,ter

F“.1 consumption (M.uNIT. /Hr.)e

~“el Rote (M,uNT,/SHP-H,. )

fuel R.(9 Corrmlio. for Fuel U,.d c

Higher or L..er H.otlng value HW b or w b(8Tu,w.uNm)

tirrectbn F=f.c for Hwt Avoiloble I

hti.ntS, r.m~u,. ( ‘r)

hbi.”t Al, Pr..sure (-HC)

Sbft Swd (RPM)

T“tiin. (RW)

@mPmsr (RPM)

&wrtio, bd (KW)

ti.tilh.g Pknt hd (WO)

sip S.tic. Strom

I I I I I

101.1 C.mation II I I

Ship Name I Trial Date

Time of Test I

Duration of Test I

Test Design Deviation

P~

Average Shaft Horsepower ISHPISteam/Condensate Flow /

Moa8u red Flowa (Lbs. /Hr, l

‘\ /’Flow Adj”stmentsb ILbs ./Hr .)

Adj”stnd Flow (Lbs. /Hr.)

Flo. Rate (Lbs. /SHP-Hr. ) ,/> ~\\

Plant Condltlon Corrections

Inlet Steam Pres8ure IPSIGI

Pres6”re Correction

1. 1.1 Steam Temperature 1°Fl

Temperature Correction

Exhdus L Preesure lHgA)

Exhaust Pressure Correct Ion

Shaft Speed [RPM)

Spead Correction

Total Correction Factor

Corrected Steam Rate (L bs, /S HP-Hr.1

a. [f condensate GPM 1s measured, meter corroctlon should be applied and

condensate temperature should be considered.

b. Flow adjustments Include allowance fOr Valva stem leakage. turbine

qland leakage and alr ejmctor drain.

NOTE: Make 8eparate evaluation sheet for test at each specif!ed power.

FIG. ~ Main Propulsion Turbine Stem Plant Test

95

PROPULS 10N PLANT DATA

Data which typically pertain to propulsion systems are set forth below.

These data should be recorded as pertinent and available subject to the

class ificat ion described below for economy trials, ahead endurance trials, and

astern endurance trials, in addition to that called for elsewhere.

Average values for the trial period should be reported. In cases where

more than one instrument is installed to read the sae datum, the instrument

of greatest inherent precision should be reported. If precision and ~ality

of calibration are e-al, their average should be used.

As noted in 6.1 and 6.2 hereof, the preBence of an instrument to read it

must be provided. Yet, data for basic design parmeters are necessary to

evaluate performance and should be provided in suitable precision regardless

of presence or @ality of ship’s instrumental ion. To a lesser degree

ancillary parmeters which are applied as correction factors to the basic

determination should also be provided commensurate with the effect on the

basic performance determination.

It is helpful in providing an appropriate data plan to categorize data

items as follows:

Class A: Oata items for which a trial instrument is rewired to

provide precision or redundancy regardless of the presence

of a ship’ s instrument, or its qality.

Class B: Data items for which a ship’s instrument of suitable

precision can be used if specifically calibrated. (A trial

instrument should be supplied if there is no ship’ s

instrument. )

Class c: Data items for which ship’s instruments with standard

calibration can be used. (If there is no ship’ e instrument,

a trial instrument need not be installed. )

When formulating a data plan, data items should be listed and

categorized as illustrated by the listings below. Data obtained from test

instruments should be suitably indicated both in the data plan and the reprt.

Note: This Fi~re includes 10 Data Sheets which are provided on pages 96

through 105.

FIG. ~ Propulsion Plant Data

96

Ship Nme

Trial Date

Trial: Economy, Ahead Endurance, Astern Endurance, Boiler Overload

Shaft Horsepower

Shaft Speed

Time and Duration of Run

Users should develop their own format for reporting the results of this

test depending upon the e~ipment available. However, the following

information should be recorded. Note that the information is divided into the

following categories: ‘“Stem Turbine Plant, Electric Drive, Diesel Propulsion

Plant and Gas Turbine Plant.

STEW TURBINE PLANT

Boilers

Boiler Promr

Drum Pressure P/s

ClaBs B Superheater Outlet Pressure P/s

ClasB A Superheater tit let Temperature P/Sa

Reheater Inlet PreBsure P/Sb

Class B Reheater titlet Pressure P/Sb

Reheater Inlet Temperature P/Sb

ClaBB A Reheater titlet Tem~rature P/Sb

Desuprheater titlet Pressure P/s

Desuprheater ~tlet Temperature P/S

COfiuetiOn Control

Pertinent cotiustion control data to be reprted

Cotiustion Air

Air Temperature to Air Heater PJS

Air Temperature from Air Heater P/s

stem Temperature to Air Heater PfS

Stem Pressure to Air Heater P/S

Air Heater Drain Temperature P/S

F. D. Fan Speed P/S

F. D. Fan Discharge Pressure P/s

Fig. ~ Propulsion Plant Data (Sheet 1 )

97

STEM TURBINE PLANT (continued)

Coti”stion Air ( continued)

Windbox Pressure P/S

Furnace Pressure P/S

Uptake Preesure P/Sc

outlet Pressure P/Sc

Uptake Temperature P/Sd

Uptake Percent C02 P/S

Uptake Percent 02 P/S

Uptake Percent CO P/S

Fuel Oil

F. O. Settling Tank Temperature

F. O. Service Pump in OperatlOn

P. O. Settling Tank in Use

F. O. Service Pump Discharg~ PreSSUre

Class B F. O. Meter Reading (Final)

Clase B F. O. Meter Reading (Initial )d

F. O. Meter Differences

F. O. Meter F1OW (GPH)dClass B F O. Meter TemFrature

Nutier of F. O. Heaters in Operation

F. O. Temperature to Heaters

F. O. Temperature from Heatersd

Stem Temperature to Heaters

F. O. Heater Drain Temxrature

F. O. Temperature at Burners PIS

F. O. Pres8ure at Burners P/S

F. O. Pressure from Burners P/Se

Nu~er of Burners in Use P/S

Burner Tip Size

F. O. Viscosityc

F. O. Specific Gravity as Metered

F. O. Heat Content Btu/lb.

Stea Atomization

stem Pressure to Burnere

Main PrOuuleiOn

Main Turbines

Nutier of Nozzles -n

Class B Main Stem Pressure at Throttle

Class B Main Ste- Tem~rature at Throttlea

H. P. Turbine Cheat Pressure

H. P. Turbine Chest Temperature

H. P. Turbine 1st Stage Pressure

Fig. ~ Propulsion Plant Data (Sheet 2 )

98

STEW TURBINE PWT (continued)

Main Turbines (continued)

H. P. Turbine 1st Stage Temperature

Croesover Ste- Pressure

Crossover Stem Temperature

Exhaust Temperature

Extraction Steo Pressuresf

Extraction Stem Temperaturesf

Gland Seal

Gland Seal Stea Pressure

Lube Oil

L. O. Pressure to Suction Strainer

L. O. Pressure from Suction Strainer

L. O. Service Pump in Operation

L. O. Service PUmp Discharge PreBSuKe

L. O. Pressure to Discharge Strainer

L. O. Pressure frOM Discharge Strainer

L. O. Pressure to Main Turbines and Gears

Nufier of L. O. Coolers in Operation

L. O. Temwrature to Coolers

L. O. TemXrature from Coolered

Coo 1ing Water Tem~rature to COOlerS

Cool ing Water Temperature from Coolered

L. O. Temperatures at Main Turbine and Gear Bearingsd

Turbine Governor Oil PK08SUre

Temperature at Thrust and LineShaft Bearings, and Other Shaft Aux.

Main Condensing, Condensate and Feed Svstem

Main Condenser

Exhaust Tem~rature

Class A Vacuume

Engine Room Barometric Pressure

‘ Condensate Taperature from Main Condenser

Cool ing Water Pressure to Main Condenser

cool ing Water Temperature to Main condenser

Cooling Water Temperature from Main Condenser

Condensate

Condensate Pump Discharge PreBsure

Condensate Tem~rature to Main Air Ejector

Condensate Tem~rature from Main Air Ejector

Stem Pressure to Main Air Ejector

Main Air Ejector Suction Preesure

Condensate Flowc

Fig. ~ Propulsion Plant Data (Sheet 3)

99

STEM TURBINE PLAWT (continued)

Condensate (continued )

Condensate Meter Temperature

Condensate Salinityc

Condensate Temperature to 1st Stage Heater

Condensate Temperature from 1st Stage Heater

First Stage Heater Shell Pressure

First Stage Heater Drain Temperature

Deaerating Feed Heater Shell Pressure

Drain Temperature

Main Feed Pump Suction Pressure

Main Feed Pump Discharge PreBsure

Data for High Pressure Feed Heaterse

Main Feed Pump Suction Temperature

Stea Pressure to Main Feed Pump

Exhaust Preseure from Main Feed Pump

Main Feed Tem~rature to Economizer P/s

Main Feed TemXrature from Economizer PIS

Main Feed Pressure to Boiler P/S

Remote Main Feed Pressuree

Auxiliarv Electric Plantd

Generator

Generator in 0p2at10n

Type (AC or DC)

Driving Unit (Stem Turbine, Diesel, etC. )

Voltage

Current

Power Factor

Class B Power titput

Loadg

Turbine

Oata available from Ship’s Instruments

Auxil iarv Condensing and Condensate Svstemd

Condenser Vacuum

Cool ing Water Pre9SuKe tO CDnden8er

Cool ing Water Temperature from COndenBer

cool ing Water Temperature to Condenser

Condensate Pump Discharge Pressure

Condensate Temperature to Auxiliary Air Ejector

Fig. X Propulsion Plant Data (Sheet 4 )

100

STEAW TURBINE P~T (continued)

Auxiliary Condensing and Condensate Svatem d (continued)

Condensate Temperature from Auxiliary Air Ejector

Auxiliary Air Ejector Suction Pressure

Condensate

Other Data

The data for the

also recommended

Salinity

following other systems as mutually agreed upon, are

for inclusion in the trial report:

Position of Ste= Pump and Makeup Valves

Distilling Plant

Auxiliary stem Systems

Contaminated Stem Systems

Other Salt Water Systems

Fresh Water Systems

Air Systems

Sewage Systeme

Refrigeration and Air Conditioning Systems

Drain systems

ELECTRIC DRIVE

Where electric main propulsion drive is installed,

should be recorded during the trial runs. The following

to alternating-current, synchronous motor installations.

electric drive will rewire data adjustments

Prime Mover

See appropriate data sheets

PCOPU 1s ion Generator

Class B Power ~tput

Voltage, Teminal

for turbine, diesel or

Voltage, Field Excitation

Current, Field Excitation

Class B RPM

Cool ing Air Tm~rature

Stator Winding Tem~ratures

Prouuls ion Motor

Power Input

Current Input

Voltage, Field Excitation

Current, Field Excitation

additional data

relates specifically

Other types of

gas turbine plants.

Fig. ~ Propulsion Plant Data (Sheet 5 )

101

STEM TURBINE PLANT (continued)

ProDu 1sion MOtOr (continued)

Class B RPM

Cool ing Air Temperature

Stator Winding Temperature

DIESEL PROPULSION PLANT

Main Enaines

Class B

(As Barometer

pertinent Engine Room Temperature

to pwer Air to Engine Pressureh

determin- Air to Engine Temperatureh

tion) Air Pressure at Blower Discharge

Air Temperature at Blower Discharge

Air Temperature Leaving Intercooler (If any)

Air Pressure in Air Box or Manifold

Exhaust Temperature Each Cylinder

Exhaust Temperature Entering Turbocharger

Exhaust Pressure Leaving Turbocharger

Exhaust Temperature Entering Silencer

Exhaust Pressure Leaving Silencer

Exhaust Temperature Leaving Silencer

Exhaust Temperature Entering Waste Heat Boiler

Exhaust Pressure Leaving Waste Heat Boiler

Exhaust Temperature Leaving Waste Heat Boiler

Crankcase Pressure

Fuel OQ

Class B Main Engine(s) Fuel Meter Tyw

Main Engine(s) Fuel Meter Reading

Propertied of Fuel Used

Main Engine Rack Position

F. O. Settler Tem~rature

F. O. Service Tank Tem~rature

F. O. Booster Pmp Discharge PreSSure

F. O. Heater In and tit Temperatures

F. O. Heater In and at PreSSuKe8

Other Pertinent Tem~ratures as Applicable (Purifiers,

Filters, etc. )

Other Pertinent Preseures as Applicable (Purifiers,

Filters, etc. )

Lube Oil

L. O. Pump Discharge PreSSuKeS

Main Engine(s) L. O. In and ~t Temperatures

Main Engine(s) L. O. In and tit Pree8ures

Fig. ~ Propulsion Plant Data (Sheet 6)

102

DIESEL PROPULSION PLANT (Continued)

Lube Oil (continued)

Gears and Couplings L. O. In and Out Temperatures

Gears and Couplings L. O. In and Out Pressures

L. O. Cooler In and Out Temperatures

L. O. CoOler In and Out Pre9surea

Other Pertinent Temperatures as Applicable (Purifiers,

Filters, etC. )

Other Pertinent Pressures as Applicable (Purifiers,

Filters, etc. )

COOlina Water

Sea Temperature

Salt Water Pump Discharge Pressures

C. W. Pump Discharge Pressures

Heat Exchanger In and Out Pressures (Salt Water)

Heat Exchanger In and Out Temperatures (Salt Water)

Heat Exchanger In and Out Pressures (C. W. )

Heat Exchanger In and Out Temperature (C. W. )

C. W. Temperature to Engine

C. W. Temperature from Engine

Starting Air Pressure

Control Air Pressure

Diesel Auxiliarv Electric Plantd

Generator

Generator in Opsrat ion

TyP (AC or DC)

Voltage

Current

Power Factor

Class B Power Wtput

Loadg

Diesel Ena~

F. O. Consmpt ion and T~ and Proprt ies of Fuel Used

Other Pertinent Data as Applicable

Boiler Svstems

Waste-Heat Boilers

Nutier in Oprat ion

Feed Preesure

Fig. M Propulsion, Plant Data (sheet 7)

103

DIESEL PROPULSION PLANT (continued)

Boiler Systems (continued)

Waste-Heat Boilers (continued)

Feed Temperature

Stem Pres Bure

Stea Temperature

Feed Flowc

Auxiliarv Oil-Fired Boilers

Nutier in OpeSatiOn

Uptake Gas Temperature

Feed Pressure

Feed Temperature

Stem Preeeure

Stem Temperature

Feed Flowc

Fuel Flow, Type and Properties

Other Data

The data for the following other syetems as mutually agreed upon,

should be included in the trial report:

Distilling Plant

Auxiliary Stem SySteMS

Other Salt Water systems

Other Fresh Water Systems

Other Air Systems

Sewage Syetems

Refrigeration and Air Conditioning Syeteme

slip COUD lina Data

Where geared diesel drive with slip couplings between engines and

gears is installed, additional data should be recorded during the trial

runs as followe:

Engine S~ed

Pinion Shaft Sped

S1 ip Sped

Shaft Sped

Shaft Horse~wer

Coupling Excitation Current (Electromagnetic)

Coupling Oil Temperatures In and ~t (Hydraulic)

Electric Drive See Sheet 5

Fig. ~ Propulsion Plant Data (Sheet 8)

104

GAS TURBINE PLANT

Main Propulsion (Each Engine)

Main Enaines

Class B Turbine and Compressor Speeds

Instrumented Points of Pressure and Temperature in the

Gas Strem

Class B Water Temperature, Barometer and Humidity

Class B Engine Air Inlet Pressure and Temperature

Class B Exhaust Flange Gas Pressure and Temperature

Critical ~ient Temperatures Around Mounted Auxiliaries

and Instruments

Lubricating Oil Supply Pressure and Temperature

Lubricating Oil Return Temperature

Vibration Monitor Readings

Gas Tem~ratures and Pressures In and Out of Intercoolers

and Regenerators

Reduction Gear and Clutch

Clutch Fluid Pressures, Air or Hydraulic

Lubricating Oil Supply Pressure and Temperature

Lubricating Oil Temperatures frOM Bearings o

Controllable Pitch Propellers

Hydraulic Operating Pressures

Blade Poeition

Fuel Oil

F. O. Consumption

F. O. Pump Discharge Pressure

F. O. Pressure to Engine

F. O. Pressure from Engine

F. O. Temperature at Meter

F. O. Settler Temperature

F. O. Temperature to Engine

F. O. ~ and Proprt ies

Lube Oil

and Temperatures

L. O. Strainer In and at PreSBureS

L. O. Cooler In and tit Tem~raturea

Cool ina Wate<

Heat Exchanger In and Out Tem~ratures

Fig. ~ Propulsion Plant Data (Sheet 9)

105

GAs TURBINE PLANT (cent in.ed)

Auxiliarv Electric Plantd

.

Generator

Generator in Operation

Fre~ency

Voltage

Current

Power Factor

Class B Power Output

LoadgDriver F. O. Consumption and Type of Properties of Fuel Used

Other Data

The data for the following other systems, as mutually agreed upon,

should be included in the trial report:

Distilling Plant

Auxiliary Boiler Data (Including F. O. Consumption)

Auxiliary Stem SySteMS

Engine Starting System

Ship’ B Service Air SySteM,,

Control Air System

Salt Water Systems

Fresh Water SystemS

Sewage systems

Refrigeration and Air Conditioning Systems

Electric Drive - See sheet 5

F-NOTES FOR FIG . 26

a Include remote and thermocouple e When appl ictile

tem~ratures when applicable.f Include data for each

b Include reheater data when avail- extract ion

able. If gas reheater is installed,

so indicate. 9 Include auxiliary machineryand hotel loads when

c When available. separable.

d Include data for each unit or h To engine intake, scavenging

system in opration. or su~rcharging blowers, as

applicable.

Fig. ~ Propulsion Plant Data (Sheet 10)

106

A. 1 PRINCIPLE

APPENDIX A TO C~PTER 6.0

CONCTING TURNING CIRCLE PLOTS FOR DRIFT

A. 1.1 The plot derived from shore

based reference station data

indicates the ship’s overground

track, i.e. , over the sea floor.

What is wanted is the track through

the water, as this is what i5

characteristic of the ship, not the

track reflecting the particular

condition present during the trial.

Comparisons of ship with ship or

ship with a standard are valid only

if both are drift corrected. The

tracking precision available from

modern positioning eystems makes

drift correction meaningful. Drift

correction is not recommended for

imprecise tracking methods.

A. 1.2 After the ship’s turn reaches

e~ilibrium, and there is no drift;the ship’s track will be a ~rfect

circle, and repated turns will

coincide. If there is drift, trackswill be distorted circles, and no

two will coincide. The degree and

location of distortion can be uead

to measure drift. The procedure is

outlined below. The tem “Execute”

as used in the procedure means the

time at which the helm order isgiven.

A .2 PLOTTING OWRGRO~ TMCK

A.2. 1 Plot the change of ship’s

heading versus time (S~) .

A.2.2 Plot the ship’s psition

versus time (SPVT) .

A.2.3 Using the SPVT, determine

ship’s position at suitable time

intervals (say 30 seconds) .

A.2.4 Plot ship’s position at the

selected intervals, on rectangular

coordinates, as shown in Figure 27,

using base course for the horizontal

axis and orienting the plot to show

the ship approaching from top left

for a right turn or bottom left for

a left turn. Use a scale sufficient

to resolve the drift distance

encountered.

A.2.5 Fair a dashed line through

the plotted points. This will

represent the overground track of

the ship during the maneuver.

A. 3 DETEWINATION OF DRIFT

A. 3.1 The test procedure stated in

paragraph 3.7 calls for holding full

rudder until ship’s heading has

changed 540 degrees; thus, the

second time around will lap the

first by 10 degrees, some part of

which will be a factor where the

drift displacement of the second

circle was maximum, and there was a

steady rate of turn both times

around. The point at which a steadyrate of turn is reached can be

verified from the S~; the Pint

will be where the slope of the

change heading curve is

approximately constant.

A. 3.2 Detemine from S~ the time

for heading changes at 10 degree

intervals for the prtion of the

107

lapped sector of the first circle

for which turning rate is steady and

the displacement of the second

circle is maximum. Similarly

determine the time to reach selected

heading change points plus 360

degrees. Determine from the SPVT

the ship’s position at these times.

Plot these positions as indicated on

Figure 27.

A. 3.3 Connect the plotted position

points at which ship’ s heading is

360 degrees apart and which fall

within that portion of the lapped

sector for which turning rate is

steady. If there are insufficient

points to describe the tracks

properly, plot more points using the

SHVT and SPVT. The mean length of

these connections will be

proportional to the distance the

ship drifted during a full turn; the

proportionality factor will be the

scale of the plot. The mean

direction of the connections taken

from first toward the second timethe eme heading is reached will be

the direction of drift relative to

base course. Indicate drift

direction by an arrow as shown on

Figure 27. Drift direction in

compass terms can be obtained by

adding or subtracting base course aeappropriate. Report on Figure 6.

A. 4 DETEWINATION OF DRIFT ~TE

A. 4.1 Determine the the from“execute” for each of the connected

pints, u:ing the SHVT.

A.4.2 Subtract the ttie to reach

the heading the first round from the

time to reach it the second round,

A. 4.3 Take the mean of these values

as the mean time to turn 360

degrees.

A.4.4 Divide the mean drift

distance as plotted by the mean the

for a 360 degrees turn to obtain themean rate of drift expressed in

inches of plot per second from

“Execute,,.

A. 5 PLOTTING THE DRIFT CORRECTED

TURNING CIRCLE

A. 5.1 Using the time plots,

determine the time to or from

‘vExecute,, for each plotted point ofthe overground plot.

A. 5.2 Multiply the times from

“Execute” for each plotted point by

the drift rate. This will be thedrift distance in inches of plot.

A. 5.3 Taking the ,,Execute,, point as

the origin representing zero time

and zero drift, lay off a line

extending from each plotted point in

a direction opposite the direction

of drift after ‘Execute, - and indirection of the, drift before

,-Execute” .

A. 5.4 Mark off on these lines a

distance representing drift as

prepared for paragraph A. 5.2. These

points will define the drift

corrected track.

A.5.5 Pick up a best-fit center

using a compass for the drift

corrected points which are in the

prtion of the track in which the

turning rate is steady.

A.5.6 Draw a best-fit circle around

this enter.

A. 5.7 Fair a line through the

remaining pints, including a few

prior to “Execute”, to redefine the

base course.

A. 6 DETEWINATION OF TU~ING CIRCLE

DI~NSIONS

A. 6.1 Scale off the corrected plot

and multiply by the scale factor the

dimensions defined in paragraph 7.3,

DEFINITIONS .

108

A. 6.2 Determine the change of

heading for each plot point for

corrected circle using the SWT.

When plotting a circle for paragraph

A.6.3. indicate the ship’s heading

by orientation of a scaled

representation of the ship’s outline

as shown on Figure 6.

A. 6.3 Replot the corrected circle;

aPP1OPKiately label and indicate theturning dimensions as illustrated in

Figure 6 and include this in the

trial report.

A. 7 CALCULATION OF DRIFT RATE IN

XNOTS

A.7. 1 Multiply the drift rate in

inches of plot per second from

paragraph A.4.4 by the scale factor

and apply a dimensional constant to

convert to knots. Report on Figure

6.

Exmple:

Drift Rate = Drift rate (inches lsec) X scale factor (feet or vards/inchi

in Knots Dimensional constant (feet or yards/nautical mile) (hourlsecs)

109

:

. ;\ h5+”

3“’-s’’’”=’170 ----~

‘-~~:?:;;y,W,,,,,,,,,,,,fis,,G 0.79 ,..—/ HwDINCS AS PLO~ED-0.79,N

--- Sin .- 633 SEC *“G TIME rOR 360. HOGC. ANCE- +06 scc

!.

. .

,,

7.0 DEFINITIONS

. .

.

The terms defined below were

selected to contribute to the

clarity of the foregoing sections.

No attempt has been made to cover

all the shipbuilding terms which may

be of interest and no claim is made

that the definitions provided

represent an industry concensus.

The definitions do, however, tell

what is meant whenever the term is

used in this guide. They are not

identical with definitions used in

other SN- publications, but they

do not conflict. Definitions are

set forth as they apply to sections

of the guide.

7.1 GENERAL TEWS

First-of-a-class - the first ship

built to a specific design by a

particular shipyard.

Forensic Data - data relative to

maneuverability and other ship

characteristics which might have a

bearing on legal action involving

the ship or its owners.

Acceptance Authority - the

organizations designated by the

Owner Or COntraCt tO rule on theacceptability of trial ~rfomance.

Reaulatorv Bodies - the

organizations designated by the

owner or by law to enforceregulations relative to the safety

of the ship, its crew or cargo, for

ex~ple: U.S. Coast Guard,

International Comission for Safety

of Life at Sea, U.S. Public Health

Service, Canadian Ministry of

Transport.

Classification Society - an

organization which publishes

standards of construction forvarious claeses of ships, monitors

their observance and maintains a

register listing each vessel

classified and giving its class and

principal characteristics. For

exaple: ~erican Bureau ofShipping, Lloyds Register of

Shipping, Det Norske Veritas.

“If Elected” - a term used in this

guide to designate a trial or test

which will be accomplished only if

explicitly rewired by the contract

or specifications.

Uncertainty - the probability that

measurement of a ship’ s performance

par=eter will not be within a

prescribed range.

Sea Trials - at-sea operation of a

ship’ 8 propulsion plant and other

ships’ machinery and systems which

cannot be properly tested at the

dock, to detemine performance

capability or to demonstrate

satisfaction of re~irements.

Builder’s Sea Tr ials - preliminary

sea trials conducted by the builder

to verify readiness for official sea

trials. Upon agreement between the

builder and acceptance authority,

specific trial events may be

officially conducted during

builder’ s trials.

Official Sea Trials - sea trials

conducted to demonstrate

acceptability of the ship to the

owner or his designated

repreeentat ive.

111

Full Load Draft - the maximum draft

permitted by the cognizant

classification society for the

season and waters in which the

trials will be conducted.

Ballast Draft - the maximum drafts

obtainable without use of dry cargo

spaces, using the ship’s ballast

sy5tem as installed.

Trial Drafts - the drafts during the

trial under consideration. See

4. 10(d) for method of determination.

Free Route - operation of the ship

on a elected course with minimum use

of the helm without restriction from

shallow water effects, channel

constraints, or traffic.

7.2 PROPULS ION PWT TRIMS

Endurance Trial - a period of

operation of the main propulsion

plant at maximum design horsepower

or a designated fraction thereof,

intended to demonstrate the ability

to perform indefinitely at that

level.

Economv Trial - a period of

operation of the main propulsion

plant to demonstrate the ability to

meet a specified rate of fuel

consumption at a prescribed ~wer

rate under stated conditions.

Main Propulsion Turbine Stea Rate

~ - a ~riod of opration of the

main propulsion turbines intended to

demonstrate the tiility to ~rfom

at a s~cif ied power level under

specified conditions at a prescribed

rate of stem flow.

Boiler Overload Test - a ~riod of

opration of the main propulsionboilers intended to demonstrate the

ability to perfom at a s~cified

overload stem output condition.

Prime Mover - the propulsion plant

element that converts the thermal

energy of the Ste- or the chemical

energy of fuel into rotary

mechanical energy.

Power Train - all elements between

the prime mover and the propeller,

inclusive.

Horsepower - power developed by the

ship’ B propulsion plant expressed in . .English units is 1 horsepower =

33,000 ft.-lb. per minute, and

expressed in metric-units is 1

horsepower = 75 kg-meters per

second. Mar itime usage

distinguishes between horsepowers

de~nding on the point in the power

train at which the measurement is

taken or to which it is referred.

Indicated Horsem wer - power derived

from the cylinders which is

determined by dimensions, pressure,

and reciprocation data before

correction for internal losses and

power supplied to attached

auxiliaries.

Brake-Horsepower - pwer delivered

by the prime mover output flange

after supplying engine attached

auxiliaries, but before takeoff of

pwer absorbed by sped reducers or

tor~e transmitting devices.

Shaft Horsem wer - the net power

supplied by the pro~lling unit to

the propulsion shafting after

passing through all sped reducing

and other transmission devices and .

thrust bearings, and after ~wer for :.all attached auxiliaries has been

taken off. Loeses between the

output flange of the prtie mover and

the pro~ller are usuallynegligible.

112

.

.

,

Normal shaft Horsepower - the shaft

horsepower used to specify design

cruising radius and eervice life.

Recent practice is to use maximum

design shaft horsepower for all

design considerations.

Maximum Desian Shaft Horsepower -

the maximum shaft horsepower for

which the ship is designed to

operate continuously.

.Classification Shaft Horsepower -

the shaft horsepower appearing in

the register of the cognizant

classification Society. In the case

of mbiguity in the manufacturers’

designation, the classification

shaft horsepower should be

considered the maximum design shaft

horsepower.

Trial Shaft Horsepowers - these are

distinguished by the method by which

they are obtained as follows:

Torsiometer Installed -

horsepower being transmitted

by the shaft at the point of

torpe measurement.

No Torsiometer - Power

Derived from Comparison with

Shou Data - horsepwer

delivered by the shaft at the

pint corresponding to the

location of the shop @wer

measuring device, with

adjustments for any

power-~ sorbing e~i~ent not

present at the shop test.

No Tors iometer - POweK

Derived from Prime Mover Data

- net horsepwer after

subtracting from the prtie

mover data estimates of the

~wer absorbed by sped

reducing or other transmission

devices, and attached

auxiliaries.

Fuel Rate - hourly consumption of

fuel by weight at a specified power

level with specified systems in

operation.

Corrected Fuel Rate - the fuel rate,

all purposes, as derived from test

data, corrected for deviations from

design conditions. The conditions

for which corrections are to be made

and the factors to be applied are as

specified or agreed.

Specific Fuel Rate - fuel rate as

defined above divided by the shaft

horsepower at which said fuel rate

is obtained. Expreseed in pounds

per shaft horsepower hour.

7.3 mEWRING AND SPECIAL TESTS

Turninq Circle Terms

Base Course - ship heading at the

start of a maneuver.

Advance - the distance the ship

moves in the direction of the base

course.

Advance-to-Clear Base Course - the

distance the ship moves in the

direction of the base course from

the initiation of the held order to

the pint at which every part of the

ship is clear of the projected base

course.

Advance-to-Chanae Headina 9D” - the

distance the ship movee in the

direction of the base course from

the initiation of the helm order to

the mint at which the ship’s

heading has changed 90°.

NOTE : This dtiension is understood

if “advance” ie used alone.

HUimum Advance of Anv Part of the

U - the maximum distance the shipmoves in the direction of the base

course after the helm order is

given.

113

Transfer - the perpendicular

distance from projected base course

to the mid length of the ship when

the ship, s heading has changed 90”.

Tactical Dimeter - the

perpendicular distance from the

projected base course to the mid

length of the ship when the ship’s

heading has changed 180°.

Maximum DeDarture From Base Track -

the maximum perpendicular distance

from the projected base course of

any part of the ship during the

turning circle.

Final Dimeter - the diaeter of thetrack made by the ship after the

rate-of-change of heading becomes

constant.

Z-Maneuver Terms

Overshoot - difference in degrees

between the departure from base

course when the oppsite helm order

is given and the maximum departure

from base course in a given

direction.

w - time from initiation of

“Z” maneuver until the ship! 8

heading returns to base course. The

“Z” maneuver ie discussed inparagraph 3.8.

_ - time rewired for ship’s

heading to change from 10”R of base

course back to 10”R of base course

in response to rudder movments of

10”R to 10”L to 10”R.

Quick Reversals

Dutch Loq - method of determining

movement of the ship by throwing a

buoyant object (log) overboard from

a forward station and throwing

succeeding logs on a signal

determined from when the proceeding

log passes a ship station at known

distance aft. The total movement ofthe ship is the product of the

nutier of logs passing the aft

station and the distance between

stations, plus the estimated

distance between the forward station

and the last log when the ship is

dead-in-the-water.

Ahead Reach - the distance the ship

moves ahead after an astern signal sis given, comonly determined during

trials for a full ahead initial. .

condition and a full astern signal. &

7.4 STANDARDIZATION TRIALS

Radiometric Trackina Svstems -

electronic systems by which ship’s

position is determined from two

carefully surveyed points ashore by

the radio signals which indicate the

range between the ship and each

surveyed point. The ship’ s position

at a particular time is the

intersection of the two rangee thus

detemined, and a series of suchpositions traces the ship’ s track.

The ship’ s psition is calculated

using the two ranges, the distance

between the surveyed pints, and the

position of the surveyed pints.

Standardization - opration of the

ship over a meaeured distance on

reciprocal courses at specified

draft and propulsion powers to

detemine the speeds obtainable at

such propulsion powers.

Shin’s Track - the line describing

the positions of a point on the ship ..

from which range measurements are

taken during the ~riod of interest.:,

7.5 INSTR~NTATION

Trial Instrument - a calibrated

inet rument provided by the builder

to measure a particular aspct of

ship prfomance during sea trials.

The trial instrument is normally

removed by the builder after trials.

114

-,

. ,.

.

Jackina Zero - the no-torqe Water Leq - the correction totorsionmeter reading determined by pressure gage readings necessary to

rotating the shaft in each direction determine pressure at the sensing

with the turning gear and taking the point when it is not at the same

mean of the average readings from elevation as the pressure gage and

both ahead and astern. the sensing line is known to contain

li~id.

Torsionmeter Constant - the constant

used in reducing torsiometer Red Hand Settinq - position of

signals to shaft torwe. It is adjustable fixed marker on an

obtained by calculation using the instrument dial face, which

known shaft dimensions, the prescribes the high and/or low

characteristics of the torsiometer, limits of safe operation.

and a standard modulus of rigidity

of the shaft material; or by

calibration of the torsiometer

while mounted on the shaft.

an

...

,:

115