This Guide PANEL
Hae Been Prepared M-19
By
(SHIP TRIALS) of
THE SOCIETY OF NAVAL ARCHITECTS AND MINE ENGINEERS TECHNICAL James
AND RESEARCH
E. Corlise,
PROGRAW
Chairman M. W. Hirschkowitz Ernest A. Maier R. E. Willimson Jmes R. Wittmeyer
Nikos O. Alexiou Willim G. Bullock Harmon M. Burford John E. Craft D. Richard Gipe Reviewed
and Approved by
SHIPS , MACHINERY Thomas
P. Mackey,
CO~ITTEE 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
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
. Francis Deputy
M. Cagliari
Executive
Director
\\
This Guide
Has Been Prepared
PANEL M-19
By
(SHIP TRIALS) of
THE SOCIETY OF NAVAL ARCHITECTS AND ~INE ENGINEERS TECHNICAL James
AND RESEARCH E. Corliss,
PROG~
Chairman M. W. Hirschkowitz Ernest A. Maier R. E. Willimson Jmes R. W ittmeyer
Nikos O. Alexiou William G“. Bullock Harmon M. Burford John E. Craft D. Richard Gipe Reviewed
and Approved by
SHIPS < MACHINERY Thomas
P. Mackey,
COMMITTEE Chairman 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
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 Francis
M. Cagliari
l\, Deputy
Executive
Director
.,
TECHNICAL
AND MSEARCH
BULLETIN
3-47
GUIDE FOR SEA TRIALS 1989
Prepared PANEL M-19
by
(SHIP TRIALS) of the
SHIPS , ~CHINERY
COWITTEE
Published THE SOCIETY
OF NAVAL ARCHITECTS 601 Pavonia Jersey
.. -
by AND HARINE
ENGINEERS
Avenue
City, NJ
07306
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 The panel also panel in accomplishing its task. 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
: .
v
... -
marine engineers from all fields of interest and the consensus of their cements appears in the guide as approved and ie sued.
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 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)
The alteration of the format from ,’ code” to ,s gu ideqq.
(b)
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.
(c)
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 Some accept~ility of the ship. exaples of omitted reqiremente are the extensive processing of trial data and the correcting of trial data to a design baseline when the data obtained clearly indicate that Such the ship is satisfactory. tests, trials, data processing, and data correcting should be separately and specifically invoked when desired.
The need to consider the provieione of the ,> Interti Guidelines for Estimating Maneuvering Performance in Ship Design” contained in the International Maritime Organization (IMO) 389, Circular ~C/Circ. dated 10 January 1985 as recommended by Panel H10.
The panel consisted of ship e~ iment test ex~rts from shipyards, 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
iii
It is are employed in the guide. advisable to consult the definitions section in connection with other sections of the guide.
Trial recommendations are based 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.
DISCLAI~RS
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.
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 the re~irements of the contract specifications, regulatory bodies or classification societies, or that it will perform satisfactorily and safely in service.
Section 1 of the guide includes general remarks applicable to any sea trial and provides a basic recommendation for trials to Sections 2, 3 and 4 be conducted. provide instructions for sea teste Section 5 provides a and trials. 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
,, .
w’
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
m 1.0
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 . ..................... ......... ...... ....
1 1 1 1 1 1 3 4 5 6 7 9
2.0
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 StePropulsion 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. ..... ....... ..
10 10 11 13 14
.-. . . ~ k,
3.0
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 ..................... .......... ...... ..... “Z” Maneuver ...................... ............ ...... ..... 3.8 3.9 Initial ~rning Tests.... ....... ............. ...... ...... 3.10 Pullout Testa .................. .............. ...... ...... 3.11 Direct Spiral Test... ...... .. ................ ...... ...... 3.12 Reverse Spiral Test.. .. ..................... ...... ....... 3.13 Thrueter Tests .......... ................... ........ ......
15 18 20 21 21 27 27 28 2B 2a 29 29 29 30 32 32 33 34 35
TABLE OF CONTENTS
3.14
(cent inued )
Quick Reversal from Ahead to Astern (stopping Tests ). ... ........ ......... .... .... ... ... ... .. Quick Reversal from Astern towhead ..... .... ... .... .. ... .. Low Speed controllability Maneuvers .... .... .... ... ... ... .. 510w Steaing Ability ...... ............ .... ... .... ... ... .. Anchor Windlase . .. ........ ............. ... .... .... ... ... .. Distill ing Plant .......... ............ .... .... ... ... .... .. Miscellaneous Auxiliary Systems ....... .... .... ... ... .... .. Emergency Propulsion Systems. ......... .... ... .... ... ... ... Navigation Eqipment .... ........... .. ..... ... .... ... ... ... Dyn-ic Posit iOning System. ...... ........ .... ... .... ... ...
36 37 37 38 38 39 39 40 40 40
4.0
STANDARD IZATIONTRIWS. .... ........... ......... ... .... ... ... ... . 4.1 Purpose ..... ....... .. ......... .......... .... ... .... ... ... . Genera l Plan ....... .. ......... ......... .... .... ... ... ... .. 4.2 Trial Area ...... .. ........... .......... .... ... .... ... ... .. 4.3 Wind and Sea .... .. ......... ............ .... ... ... .... ... .. 4.4 Nutierof Sped Points ...... .......... .... .... ... ... .... .. 4.5 Course Select ion .......... ............ .... ... ... .... ... ... 4.6 Operation of the Ship..... ............ ... .... ... .... ... ... 4.7 Data Re~irements ....... .......... ... .... .... ... .... ... ... 4.8 Organization of observers. ........ ... .... ... .... ... .... ... 4.9 4.10 Instrumentation for Standardization Data. ... .... .... ... ... 4.11 Coordination Procedure.. ......... ....... .... .... ... ... ... . 4.12 Tolerances and Limits ........... ........ .... ... .... .. .... . 4.13 Data Reduction ..... ........... .......... .... ... .... ... ... . 4.14 Corrections ....... ............ ......... .... .... .... ... .. ..
42 42 42 42 42 43 43 44 45 46 46 47 47 47 48
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 ..... ............ .... .... ... .... ... .... .. Tor~eand Horae~wer Measur=ents. .. .... .... ... .... .... .. 5.5 Shaft-Power Meters ... ............ ........ ... .... .... ... ... 5.6 5.7 Shaft Thrustmeters ............... ....... .... .... ... .... ... 5.8 Shaft sped measurements.. .... .. ........ .... ... .... .... ... Vibration Measurement 8 ........ .......... .... ... .... ... .... 5.9 5.10 Airborne Noiae Measurements. . ........... .... ... ... .... .... 5.11 Feedwater Teeting ....... ............... .... .... ... .... .... 5.12 Density Measurement8 ... ................ .... ... .... ... .... . 5.13 Leakage Measurements .. ................ .... .... ... .... ... .. 5.14 Flue and Exhaust-Gas Analyses. .... .... ... ..... ... .... ... ..
49 49 52 53 56 58 59 60 60 61 63 63 64 64 65
3.15 3.16 3.17 3.18 3.19 3.20 3.21 3.22 3.23
vi
-..
w’
L
TABLE OF CONTENTS
(continued)
m ..
. ....
‘4
..
.
6.0
5.15 5.16 5.17 5.18 5.19 5.20
Stea Quality and Purity Measurements ... ...... ...... ..... . Viscosity Measurements .................. ....... ..... ..... . Electrical Measurements ................. ...... ...... ..... . Wind Speed and Direction Measurements ... ...... ...... ...... Radiometric Tracking Systems. ............ ...... ...... .... . Time Measurements ... ................. ... ....... ..... ..... .
67 67 67 6B 69 70
TRIAL 6.1 6.2 6.3 6.4 6.5 6.6
DATA AND REPORT ... .................. .......... ...... .... .. General .......... .................. .......... ...... ..... .. Data Plan ....... ................. ........... ....... .... ... Data Crew Training ............... ........... ...... ..... ... Maneuvering Trials and Special Tests. ....... ...... ..... ... Standardization Trials... .... .............. ...... ..... .... Fuel Economy, Endurance, Boiler Overload and stem Rate Tests .. ............ ............... ....... ..... ..... Propulsion Plant Trials.. ................ ....... ...... .... Trial Re~rt . ........... .................. ...... ..... .....
72 72 72 73 73 73
6.7 6.8
73 73 74
OATA .. ........... .................. ....... ..... ..... .
96
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.... ......... .......... ....... .... .. Detemination of Drift Rate. ...... .. ......... ...... ..... .. A.4 Plotting the Drift Corrected Turning Circle. . ...... ..... .. A.5 A.6 Determination of Turning Circle DtienBions. . ...... ..... ... A.7 Calculation Of Drift Rate un knots ......... ....... ..... ...
107 107 107 107 10B 108 10B 109
7.0
111 111 112 113 114 114
PROPULSION
PLANT
DEFINITIONS ......... ............. .. .............. ....... ..... ... 7.1 *neral Tams . ............. .. .............. ....... ..... ... 7.2 Propulsion Plant Trials... . ................ ...... ...... ... 7.3 Maneuvering and Spcial Teeta. ........... ........ ...... ... 7.4 Standardization Trials. .................. ........ ..... .... 7.5 InstrmentatiOn ..... ..................... ....... ...... ....
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 . ... .... ... ... . RECOMMENDATIONS FOR DIESEL PROPULSION PLANT TRIALS .... ... .... .. . RECOMMENDATIONS FOR GAS TURBINE PROPULSION PLANT TRIALS .. ... ... . ACCEPTABLE DEVIATION AND FLUCTUATION TOLE~CE AND READING INTERVALS FOR STEAM ~TE TEST DATA .......... .... .... ... ... .... TYPICAL STANDARDIZATION COURSE. .... ........... .... .... ... ... ... . STANDARDIZATION TRIAL TOLERANCES AND LIMITS .. ..... ... .... ... .. .. STEERING TESTS ....... .............. .......... .... .... .... ... ... . TURNING CIRCLE TEST - RADIOMETRIC OR OTHER PRECISE TRACKING AVAILABLE ............. ............ .... .... ... ... ... .. TURNING CIRCLE TEST - RADIOMETRIC OR OTHER PRECISE TRACKING NOT AVAILABLE ........ ............ .... ..... ... ... ... .. ,, Z“ MEUVBR TEST . ............ .......... ... ..... ..... ... ... .. ... INITIAL TURNING TEST .......... .......... ... ..... .... .... ... .. ... PULLOUT TEST ..... ............. .......... ... ..... .... ... .... .. ... SPIRAL TEST ...... .............. ......... ... ..... .... .... ... .. ... REVERSE SPIRAL TEST .......... ........... .. ..... ..... ... ... ... ... THRUSTER TESTS .. ............. .......... .... .... .... .... ... ... ... QUICK REVERSAL TESTS ......... .......... ... ..... .... .... ... ... ... LOW SPEED CONTROLLABILITY HANE~R TESTS .. ..... .... .... ... ... ... SLOW STEAMING ABILITY ...... .. ......... ........ ..... ... .... ... ... ANCHOR WINDLASS TESTS ...... .......... .......... .... .... ... ... ... DISTILLING PLANT TESTS.... ........... ......... ..... ... ... .... ... DYNANIC ~SITIONINGSYSTEH TESTS ..... ......... .... .... ... .... .. . CENTRALIZEO CONTROL SYSTEM TESTS ..... ......... ..... .... ... .... ... STANDARDIZATION TRIALS .. .. ........... ........ ..... .... ... ... ... . STEAHPROPULSION PLANT ECONOMY TEST . ......... ..... .... ... ... ... . DIESEL PROPULSION PLANT ECONOHY TEST ......... ..... .... ... ... ... . GAS TURBINE PLANT ECONOMY TEST ..... .......... .... .... .... ... ... . NAINPROPULSION TURBINE STEAN P~T TEST ..... ..... ... .... ... ... . PROPULSION PLANT DATA WITH 80ATA SHEETS ..... ..... .... ... ... ... . SWPLE PLOT ILLUSTRATING CO~CTION OF TURNING CIRCLES FOR DRIFT .. ...... .. ........... .............. ..... ... .... .... .. .
23 24 25 v“ 26 45 47 76 77 7B 79 80 81 82 83 84 B5 86 87 87 88 89 90 91 92 93 94 95 96 110
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viii
GUIDE
FOR SEA TRIMS
1989
1.0 INTRODUCTION
.
.
‘J-’.;.
.,
..
1.1
This Guide for Sea Trials-1989 supersedes the code for Sea Trials1973 of The Society of Naval Architects and Marine Engineers (SNAME). 1.2
i
SUPERSESSION
ORIGIN
This Guide was developed by updating the Code for Sea Trials1973 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, dated 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 sea trials of self-propelled surface 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 Tests19s5. 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 only at 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
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
Provision
of oDerat Lna Data
It is desirable to establish a data 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.
of Endurance
Demonstration of ability to maintain maximum power and speed for sufficient time to develop e~ilibrium conditions and to so operate 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
1 .5.6
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 is factory manner is imprtant for every ship.
Ship pilots as well as Owrators alSO need to know the controllability characteristics of the vessel. IMO Resolution A. 6D1 provides a comprehensive guide to providing such data in a standard format. 1. 5.7
Provision
of Forensic
v’
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, and The IMO, for instance, procedures. ia gathering data on ship maneuverability in its developing and refining of standards and has detailed s~cific maneuvers that are included herein.
b
1.5.9
Classification Rem irements
and Safett
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.
A
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 of limited value. In such cases it is 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 In the abeence of model condition.
test data, standardization than maximum design drafts recommended. 1.6.2
Water
at other is not
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 izat ion and comparative purposes. The adeqacy 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 ~ H
and
> 0.4 V2
where: H = Water
Depth
Am = Midship
(m)
Section
V = Ship, s Speed
Area
(m/see)
(m2 )
1.6.3
Wind,
Waves,
and Currents
The uncontrollable environmental 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 Wind direction and speed available. 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
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 tests recommended 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.
are: W ParaaraDh
Recommendation Economy Triale Endurance Trials Astern Trial Main Turbine stem Rate Boiler tierload Centralized Propulsion Control Ahead Steering Astern Steering Auxiliary Means of Steering
System
First of a Class All Ships A1l Ships If Elected If Elected All Ships All Ships All Ships All Ships
Only
2.2 2.3 2.4 2.5 2.5 2.9 3.4 3.5 3.6
.
\
-, J
W
Recomendat
Turning Circles Z Maneuver Initial Turning Pul lout 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 Windlaes Distilling Plant Miscellaneous Auxiliary Systems Emergency Propulsion Systems Navigation E~ipment Dynmic Positioning System Standardization Trials
First of a Class Only First of a Class Only First of a Class Only( 1) First of a Class onl~ First of a Class Only If Elected(2) First of a Class Only All Ships A1l Ships If Elected All Ships All Ships All Ships If Elected If Elected All Ships All Ships First of a Class Only (See paragraph 1.5.2)
(1) (2)
1.8
.,
J
ion
_ ParaaraDh 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 4.0
Derived from paragraphs 3.7 and 3.8 Direct Spiral,, Alternative to ‘r
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 the major ship prfomance paraeters involve measurement of many fluctuating ~antities, each with an element of uncertainty, the cumulative effect might be 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 The approaching a laboratory. method of reference (d) should be consulted when calculating uncertainty for trials set forth in this Guide. 1.9
1 .9.1
Desian (a)
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 it iea, 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.
1.9.2
Accommodation
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 alerted to provide precise internal diameter measurements. Mount ing of signal transfer e~ipment or brush rigging should also be considered.
(b)
If special trial fuel meters or condensate meters are to be installed, systems should be designed to accommodate them.
(c)
If special gages, thermometers or orifices are to be installed, sensing points should be selected and the necessary fittings, wells or flanges provided.
(d)
If fuel oil saples are to be taken during trials, a empling connect ion or method should be provided.
b’
Pre-Arrangements L (a)
If the shaft is to be calibrated, the shafting production schedule should be adjusted to provide a calibration availability; the
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. .
(b)
(c)
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.
(d)
Signal system should be deeigned and installed.
(e)
Correct ion factors should be obtained and the concurrence of owner’s technical represent at ives established.
(f)
Data instructions and station bill should be prepared and distributed.
(9)
Spcial trial instruments should be installed and all instruments which will provide trial data calibrated, “red line” eettings made and “water legs-. meaeured.
(h)
using them Trials.
Data fores should be prepared and checked against the ship as built, preferably by
1.10
for Dock
(i)
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.
(k)
Radiometric tracking system, if to be aboard, including antenna should be installed and checked.
(1)
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.
(m)
Trial agenda, procedures and schedules should be prepared and furnished to the owners for cement.
(n)
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.
P~-TRIfi
C~CK
LIST
So many items are involved in determining readiness for sea trials that it ia virtually necessary to Such a list would use a check list. 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 Calibration
and
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 (a)
Check visually for proper instal lat ion, cleanliness of slip rings, proper engagement of brushes, and proper clearance of signal transfer e~i~ent.
(b)
Make a pre-trial check of transformer ratio or gage factor.
(c)
Obtain jacking aet indicator.
(d)
During dock trial or pre-trial plant o~rability check, verify o~rability of torsiometer.
Document (a)
Plant operating instructions and checkoff lists.
(c)
Data system operating instructions.
(d)
Data forms and calculation forms.
(e)
Fuel gravity and heat content re~rt.
(f)
Fuel temperature/gravity plots or tables.
(9)
Instrument calibration records and correction factors.
(h)
Correction factors for non-standard conditions.
(i)
Data
(])
Trial agenda, procedures and schedules.
(k)
Selected diagrms.
crew
d
instruct ions.
Readiness
1. 10.5
zero and
Check
Toreiometer constant and SHP fomula.
Sianal
drawings
Svstem
and
ODerabilitX
A pre-departure check should be made of the signal system at all stations including telephones. 1. 10.6
1. 10.4
(b)
Radiometric ~erability
Svstem
A pre-trial check of the radiometric eyetem including each element and its standby should be made using the trial antenna and Complete the check ship’s power. 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 machinery installation trial e~ipment.
of the and the
Training the operating trial personnel.
and
Making adjustments plant to establish operation.
to the proper
Determination of ability to meet performance re~irements.
2.0
2.1 2. 1.1
PROPULS ION PLANT TRIALS
To determine the rate of fuel consumption of the plant when operating at specified shaft horaepwer and other specified operating conditions.
GENE~ 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 necessary for the operation of the ship under The instructions trial conditions. 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.
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
Spcific re~irements for these types of propulsion plants can be found beginning with paragraph 2.2. 2. 1.2
SXcific
should res~ct
Objectives
Pre-Trial
Prior to the trials, there be a clear understanding with to the following:
The spcific trials.
Specific objectives of propulsion plant trials may be one or more of the following:
The trial schedule.
To demonstrate satisfactory OFration of the propulsion plant for a s~cified ~riod of time at specified horsepower, usually maximum design horsepower.
Agreements
objectives
agenda
of the
and tentative
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 e~ipment Trial
methods, and
te$t
2 .1.5
of each
trial
Fre~ency of readings measurements. Trial
run.
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.
and
Preparations
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. and calibration
2.2 2 .2.1
of
2.2.2
Calibration of special gages and Records of calibrations meters. should be available prior to trials and carried onboard during trials. of trial
e~i~ent
Ascertaining that all machinery ew iPment iS in propr working condition.
PROPULSION
PLANT
ECONOMY
-
:..
TRIMS
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.
Calibration of trial fuel meters. Where ships meters are used as trial or trial back-up instrumentation, they should also be calibrated.
Installation re~ired.
Duration
Duration of each Propulsion Plant Trial should be as set forth in Figures la, lb, and 1.c unless otherwise specified or agreed.
Preparation for propulsion plant trials as defined in thie section should include the following:
Installation toraiometer.
Trial
instrumentation.
drafts.
Duration
2. 1.4
temporary
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.
as
and
Helm changes should be held to a minimum and course changes should be made with no more than 5 degrees rudder.
Preparation of the trial ballasting plan to provide the prescribed submergence of the pro-l ler.
. 2.2.3
Control and records of fuel onboard to provide for trials a homogeneous, known, supply.
Freaencv
of Observations
Unless othemise agreed, observations and instrument readings should be taken at fifteen minute Readings of tor~e or intervals. shaft horsepower should be taken as rewired for producing, as nearly as is practicable, a continuous record,
Analysis of the fuel to be burned including heating value, spcific gravity, viscosity characteristics and other pert inent proprt ies.
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
.’
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.
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
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 of shaft revolution counters, see Section 5.0, Instrument and Apparatus for Ship, s Trials.
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..
(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.
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.
(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.
(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 it is not intended to limit or restrict
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
2 .2.7
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:
(b)
Fue 1 temperature 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)
2.2.8
Fuel chemistry, specified.
if
Trial
Reuort
2.3 PROPULS ION PLANT ENDU~CE TRIALS 2.3.1
Data
AHEAD
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.
at 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 For Endurance Trials ttie and fuel. the emphasis is on attaining and sustaining the rewired power level, and fuel rate is a secondary
Higher heating value of fuel from laboratory tests or lower heating value as agreed or spacif ied.
13
-
.
Fuel Rate Calculation
See Section 6.0, Trial and Re~rt and Figure 26.
correct ion calibration
(c)
(h)
The fuel rate for all purposes should be expressed in pounds per shaft horsepower hour or other agreed standard units for each trial run.
Fuel meter readings at start and at end of each trial interval. Fuel meter from meter curve.
Average shaft horsepower for each trial interval.
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.
Fuel Rate Data Re aired
(a)
(9)
., -. .
.
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 fstandard conditions.
(2)
On ships with direct drive, prime mover parameters and conditions, a“d manufacturer 8s shop test or design data.
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.
(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.
2 .3.2
Even when trial power is determined 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.
Measurements and Instrumental ion
Economy Trial instrumentation and data systems are generally When ade~ate for Endurance Trials. 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. .
.
2.3.3
Remrt
See Section 6.0, Trial and Report and Figure 26.
Data
2.4
TRIAL
2.4.1
PROPULSION Purwse
PLMT
ASTE~
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 vibratory conditions.
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 be omitted and pwer approximated from one or more of the following: (1)
Trial
Difficulty in obtaining unifom pro~ller loading because of submergence variations due to ship
PrOpller revolutions -r minute with model test data.
14
pitch, wave impingement or the uncontrollable circular track generally followed when a singlescrew 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.
2 .5.1
Measurement and Instrumentation
ReDort
See Section 6.0, Trial Data and Reprt and Fi~re 26. 2.5
Steam
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.
Instrument at ion and the data system should be the sme as that When for Ahead Endurance Trials. stem turbinee are the prime mover, maximum temperatures should be monitored carefully. Trial
Turbine
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 or extract 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.
Except as rewired for astern steering trials, the rudder should be held aidshipe during astern trials.
2.4.3
Propulsion Test
2.5.1. (a) Purpose. The purpose of this test is to determine the nonextraction steam rate of the propulsion turbine at the specified power.
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 In such cases the specified. 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.
2 .4.2
Main Rate
The stem rate test ~riod should be preceded by a stabilizing ~riod of at least one-half hour during which the the plant
SPECIAL CONSIDERATIONS FOR STEM PROPULSION PLANT TRIALS
OpratiOn and the prt inent data be reviewed and detemined to be satisfactory to begin the test.
This eection addresses sea trial related tests which are ~culiar to the stem propulsion plant.
15
can
.
-
. *
The stem rate should be determined 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 steady-state conditions Figure 2. 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.
Condensate pump flow should be regulated so as to maintain hotwell level in the gage glass at a preselected mark thereon. The level should 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.
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.
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.
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.
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.
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.
16
2 .5.2
Boiler
Overload
2.5.2.(b) Measurement Instrumentation.
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 steOutput .
and
(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 calibrated specified, acceptable test.
gages, as agreed are for this
t or
2.5.2.(c) Trial Data Re mired. 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:
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 offstandard 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 .
17
(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 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.
at the
●
..
(7)
Air temperature to forced draft fans or to fuel oil burners.
(8)
Fuel temperature burners.
(d)
Power transmission elements including gears, couplings, clutches, etc.
(e)
Waste heat boilers and/or auxiliary boilers.
to the
Trial RePort. See 2.5.2.(d) Section 6.0, Trial Data and Report Then select a data and Figure 26. sheet format appropriate to data rewired by paragraph 2.5.2. (c) noting the boiler tested.
Special agreements should be made prior to trials for observing the performance of the auxiliary component e mentioned above.
2.6
2.6.2
.’ SPECIAL CONSIDERATIONS FOR DIESEL PROPULS ION PLANT TRIALS
Sme as paragraph 2.2 except for diesel installations having a s 1ip type COUP1 ing between the engine and the shaft; then, both engine revolutions and shaft revolutions should be obtained.
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 A major 2.2 through 2.4 above. pur~se of the Economy and Endurance trials is to provide base-line OPrating data for the entire plant when using service fuel, and the sea trials should be planned and carried out with this in mind. 2.6.1
Auxiliarv
Revolutions
2.6.3
Fuel Measurements
Sme as paragraph 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.
Comwnents
The following are exmples of auxiliary compnente which may be part of a diesel plant: (a)
Turbochargers, reciprocating or gear t~ blowers, or other aourcee of cotiustion or scavenging air pressure.
(b)
Engine-driven lube oL1, fuel or cooling fluid preps .
2.6.4 .
(c)
2.2 except
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 for variations of the following data from design conditions should be provided by the engine manufacturer:
Independently driven generators, pumps or centrifuges.
18
(a)
Inlet air temperature.
(b)
Inlet
air pressure.
(c)
Inlet air moisture content.
(d)
Engine
(e)
Exhaust
(f)
Fuel oil heating
the BHP may be computed with 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.
RPM. pressure. value.
The purpose of these corrections is to properly evaluate Suitable diesel engine performance. test devices should be provided on trials to accurately measure these variables. 2.6.5
Each of the above methodB may be used to determine brake horse~wer. An agreed allowance for gear or coupling los Bes must be applied to obtain shaft horsepower, if these elemente are in the power train.
W
When torsiometera are not rewired to be fitted, brake horsepower for diesel engines may be estimated by the following methods: (a)
(b)
(c)
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.
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.
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.
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. Indicator Indicator
#
2.6.7
Trial
Oata
and Rewrt
See Section 6.0, Trial and Reprt and Figure 26.
Cards cards or
eqivalent may be taken on each cylinder, and 19
Oata
“
2.7
..
SPECIAL TURBINE
2 .7.2
CONS IDEATIONS FOR GAS PROPULSION PLANT TRIALS
Fuel rate corrections for variations of the following from design values should be provided by the gas turbine engine manufacturer:
This section covers sea trial related items which are peculiar to This gaB turbine propulsion plants. 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
PrecOOlers, intercoolers, coolers.
Inlet air temperature.
(b)
Inlet air moisture content.
(c)
Power turbine
(d)
Inlet air pressure.
(e)
Exhaust
RPM.
Reheaters, regenerators, and recuperators.
(c)
Fuel conditioning em i~ent.
(d)
Inde~ndent generators
(e)
Control e~i~ent safety devices.
(f)
Power transmission elements including gears, clutch, shaft brake, coupling, controllable pitch pro-l ler, etc.
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.
and after
(b)
ly powered and pumps. and
2.7.3
(9)
(a)
Component S
The following are ex-pies of auxiliary components which may be part of the gas turbine plant: (a)
Fuel Rate Data Rew ired
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.
Waste heat or independent ly fired boilers.
SPC ial agreements should be made orior to sea trials for observing the performance of the auxiliary components mentioned above.
When tors iometers are rewired to be fitted, a correlation should be established during trials
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
2 .7.5
Trial
2.a.2
and Reprt
SPECIAL CONSIDEWTIONS FOR ELECTRIC DRI~ PROPULS ION PLANT TRIALS
2.8.3
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
Independently pumps .
(c)
Attached
(d)
COntrOl e~ipment safety devices.
(e)
Power transmission elements including gears, clutches, shaft brakes, couplings, controllable pitch propeller, etc.
powered
pumps. and
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.
See Section 6.0, Trial Data and Report and Figure 26. 2.8
(b)
units.
Special agreements should be made prior to trials for observing the performance of the auxiliary components listed above.
shaft horsepower. Data
Heat exchanger
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 The density and heat ing value. 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
(a)
Trial
Data
and Rewrt
See Section 6.0, Trial and Re~rt and Fi~re 26. 2.9
2.9.1
CENTRALI ZEO PROPULSION SYSTEM TEST
Data
CONTROL
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 1s ion plant resynse during transient OpratiOn at spc if ied rates and initial and final conditions.
Comwnents
The following are exaples of auxiliary com~nents which may be part of the electric drive propulsion plant.
21
,
2.9.2
Procedure
demonstrated under free route, maneuvering and emergency conditions in accordance with the sea trial agenda agreed to in advance.
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 operation 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.
i
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 the control system or setting up conditions beyond the operating range of the propulsion system.
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
2.9.3
Trial ReWrt
See Section 6.0, Trial and Reprt and Figure 20.
.
22
Data
of
SNAMS GUIDE
FOR SEA TRIALS Boiler Overload
Ahead Endurance
Astern Endurance
Economy
Steam
OURATION MWR LEVEL
4 Hoursn Max Des igna
30 Minutes Max Continuous
4 Hoursa Servicea
CRITICAL MEASUREMENTS DATA INTERVAL FOR CRITICAL MEASURE~NTS
Power
Tor~e/RPM
Power Level & Fuel Coneump
1 Hour As obtained from nozzle setting Power & Steam Flow
1 Hour As required to load boiler Fuel Consump””
15 Minutes TorWe RPM StePress Stem Temp Prop Pitch PRPLS MOtOr KW Vacuum Exh Temp Plus Mfq” 6 Lim Minus 2%
10 Minutee Torpe RPM StePrees Stem Temp Prop Pitch PRPLS Motor KW Vacuum Exh Press Plue Mfr, s Lim Minus 10%
15 Minutes S-e ae Ahd Endur plus : Fuel Aux Load
10 Minutes Torque RPM Steam Press Steam Temp PRPLS Motor Vacuum Exh Temp Cond Flow
15 Minutes Fuel F1OW FO Temp Steam Press Steam Temp Stack Temp Air Press
Plus 5% Minus 50
See Text
Plus 5% Minus O%
PIUS 5a Minus 5%
PIUB Mfr Os Lim Minus 2Da
Plus 50 Minus 50
See Text
Plus 50 Minus 5%
Power or RPM
Torpe, Chest Astern
Power
POwe r
Fuel Flow
Nozzles
Boiler Controls
TRIAL
SUPPORTING DATA (as prtinent )
E DEVIATION OF CRITICAL HEASUREMSNT AVERAGES FROM LEVEL SPECIFIED FLUCTUATION OF INOIVIDUAL DATA ITEM FROM AVERAGE FOR CRITICAL ~AsuREMNT PLANT CONTROL PAWTER ~ANS OF CONTROL
Ahead
Throttle
RPM or Prees Throttle
Combustion Air Temps
or RPM
Nozzles
Rate
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 Trial immediately (alternatively recommended) . FIG. la. RECO~ENOATIONS FOR STEAM PROPULS ION PLANT TRIALS
.,
KW
if it fol lows the Economy
‘“
. ..
,,
sN~
GUIDE
FOR SEA TRIALS
Ahead Endurance
Astern Endurance
DURATION POWER LEVEL
4 Hoursn Max Continuous Rat ing
30 Minutes Max Astern Rat ingn
CRITICAL MEASUREMENTS INTERVAL FOR CRITICAL MEASUREMENTS
Power
Tor~e/RPM
15 Minutes
10 Minutes
Toraue RPM Prop Pitch PRPLS Motor KW Rack Position Max Cylinder Firing Preesure Power or RPM
Toraue RPM Prop Pitch PRPLS Motor KW Rack Position
TRIAL
SUPPORTING DATA (ae ~rtinent )
PLANT CONTROL
P~TER
,
TOr~e
Economy
4 Hoursa Cent inuous Service Heating
Cent inuous
Power Level & Fuel ConSump 15 Minutes Sae as Ahd Endur plus : Aux Load Fue 1
FO Ht Content Air Intake Temps Power Or RPM
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 the Economv Trial immediately (alternatively recommended) . b To be in accordance with Classification Society requirements. FIG.
lb.
RECOMMENDATIONS
FOR O IESEL PROPULS ION PLANT
TRIALS
to two hours
if it follows
SNWE TRIAL
DURATION PONER LEVEL CRITICAL MEASUREMENTS INTERVAL FOR CRITICAL MEASUREMENTS SUPPORTING OATA (as prtinent )
LNn
DEVIATION OF CRITICAL MEASUREWENT AVBRAGES FROM LEVEL SPECIFIED FLUCTUATION OF INDIVIDUAL DATA ITEM FROM AVERAGE FOR CRITICAL ~ASURS~NT PLANT CONTROL PARAWETER MEANS OF CONTROL
GUIDE
FOR SEA TRIALS
Ahead Endurance
Astern Endurance
Economy
4 Hoursa Max Oesigna Power
30 Minutes Max Continuous Torque/RPM
15 Minutes
10 Minutes
4 Hoursa Service” Power Leve 1 & Fuel ConSump 15 Minutes
TorWe RPM Prop Pitch PRPLS Motor Exh Temp
Torque RPM Prop Pitch PRPLS Motor Exh Press
KW
Same as Ahd Endur plus: Aux Load Fuel KW Air Intake Plus 5% Minus 5%
Plus Mfg, s Lim Minus 2%
Plus Mfr)s Minus 10%
Plus 5% Minus 59
Plus Mfr, s Lim Minus 20%
Plus 5% Minus 5%
Power Ahead
Torque Astern
Power Ahead
or RPM of Throttle
Lim
RPM Throttle
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 the Economy Trial immediately (alternatively recommended ). b To be in accordance with Claesif ication Society requirements.
Temps
or RPM Throttle
a Endurance
FIG . 1. C
,,
RECOWNDATIONS
FOR GAS TURBINE
PROPULS ION PLANT
..
to two hours
TRIALS
,
if it follows
.
.
-,
Dev iat ion of Average From DeSian Inlet Stem
Pre SSure
Inlet Stea
Temperature
Exhaust
Pre8eure
- %
- In. Hg. fia.
RPM - 8
Shaft
Horse~wer
m
10
~ 25
10
~ 0.5
Stem
(Condensate)
10 +2
~5
- 0 Flow - Gal.
ACCEPTABLE
Data Interval
~3
+ 10 -5
Shaft
FIG. 2. N
- ‘F
Fluctuation of Reading From Averaae
---
OEVIATION AND FLUCTUATION TOLE~NCE FOR STEM RATE TEST OATA
10
10 ---
AND RBAO ING INTERVALS
3.0
3.1
SELECTION
WE~RING
AND SPECI~
operating regulations or providing data for future designs. The subse~ent utility of the data should be the basis for 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
TESTS
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 liable to be encountered.
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
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 selecting tests, cons iderat ion should be given to their pur~se. Some are intended to demonstrate ~rfomance of vital machinery and sat isf y re~latory Some are easent ial to re~iremente. 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
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
3.4
a much lower proportion of design speed. The following formula is suggested as a guide to selecting test epeed: VT= where:
‘D CB
speed
= design
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.
speed
= block coefficient the design draught
at
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
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.
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 Test conductors and data advance. takers ehould be instructed in their duties, shown their station, checked out on instruments and have their understanding of the test verified. 3.3
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:
CBXVD
VT = test
AHEAO
The following data should be recorded on Figure 5 during the test: (a)
Time of test
(b)
Time re~ired movement.
(c)
Maxtium
rudder
(d)
Maximum
oil pressure
(e)
Servo pressure, replenishing pressure and pump stroke at maxtium demand, if avail tile from shiv’s instruments and indicators.
(f)
Power unit volts, aps
and base
course.
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.
28
for each
rudder
anglee.
in use and and RPM.
on rm.
idle
,
(9)
Steering gear motor minimum and maximum volts, mperes, and RPM for each rudder movement.
(h)
Propeller shaft RPM at start and finish of test on each unit.
(i)
Depth of water, sea condition, and wind direction.
(])
Steering
(k)
Trial
station
drafts,
movements, the time necessary to secure 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
ASTERN
fore and aft.
The essential information to be obtained from this maneuver consists of tactical diaeter, advance and transfer. Also of 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.
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:
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:
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 paragraph 3.4 dove. 3.6
AUXILIARY
~ANS
CIRCLES
Turning circles should be performed to both starboard and port with 35 degrees rudder angle or the maximum design rudder angle permissible at the test speed.
in control.
The above test is appropriate for dual power unit electrohydraulic systems. If a different system is installed, suitable adjustments to the re~irements should be made. 3.5
TURNING
Move rudder to HardOver and hold until ship’s heading changed 540 degrees.
in
Resme a straight restore sped.
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
course
Move Rudder to Hardover and hold until ship’ s heading changed 540 degrees. Resume
a straight
Right has
and
Left has
course.
Throttle setting for singlescrew 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.
(f)
Shaft RPM at beginning of each circle.
The following data recorded or derived:
(9)
Depth of water condition.
and sea
(h)
Wind direction
and velocity.
(i)
Trial
Time
(b)
Rudder
(c)
compass reading to nearest degree every 10 seconds that ship is in the turning maneuver.
(d)
(e)
and end
should be
(a)
of teet,
radiometric e~ipment is not installed, ship, s track should be obtained by radar, shore station tracking, or visual observation of the wake. Observation intervals should coincide with heading data intervals.
and base course.
angle. draft
fore and aft.
Circle tests may be specified at depths, drafts, speeds, and rudder angles other than those given, if ship’ s maneuvering characteristics re~ire further exploration.
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 a plot of time against heading.
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 and Ap~ndix A to 6. See Fi~re Chapter 6 when precise tracking is available. 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:
Ship’ s psition at suitable intervala from radiometric eqipent, if installed. If
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.
The essential information to be obtained for the ,~Z,,Maneuver is the initial turning time, time to second execute, the time to check yaw, 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.
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.
The following data recorded or derived:
Move the rudder from 10 degrees right to 10 degrees left hold until original heading is Steady on original restored. 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 A pullout test for other analysis. 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 The 20°/200 test characteristics. should also be included to provide a comparison with data availsble from For stiilar rea80ns earlier tests. of comparison the 20”/10° test may The be taken into cons iderat ion. 20”/10° tests are fre~ently perfomed in long towing basins, in narrow waters, and for reasons of special analysis.
31
should
be
(a)
Time of test and base course.
(b)
Time of shift rudder, start and etop of actual rudder mot ion.
(c)
Time rudder position.
(d)
Compass reading to the nearest degree every 10 seconds that the ship is in the “Z” Maneuver.
(e)
Shaft RPM at beginning of test.
(f)
Wind velocity
(9)
Oepth of water condition.
(h)
Trial drafts,
(i.)
Ship’s track from radiometric data, if e~ipment is installed.
is held at each
and end
and direction. and sea
fore and aft.
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.
(3) (4) (5)
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
(b)
3.10
Lay the rudder over to the specified setting and hold until the turning becmes steady.
Before (1) (2)
starting
Rudder angle. Gyro compass reading every 10 seconds to the smallest fraction of degree readable.
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.
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.
(a)
the test:
Both heading and rate of change of headings should be plotted for each rudder position.
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 are described in Sectione 3.7 and 3.8, res~ctively.
The following data recorded on Fi~re 9.
During (1) (2)
TESTS
Wind velocity and direction. Depth of water and sea condition. Trial draft.
Each test consists of a prt and starboard run as follows:
should be Attain a eteady turning rate with a fixed rudder angle of approximately 15 degrees to 35 degrees. The engine control settings are kept constant.
the test:
Time of teat and base course. Ship aped and corres~nding RPM.
Return rudder to midship’s psition, and record time.
32
Move
Record heading, ship speed, and pro~ller RPM at 10 second These recordings intervals. 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 as shown on Figure .3.11
THE DI~CT
SPI=
be reported 10.
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.
TEST
The direct spiral test is an orderly se~ence of turning circle tests to obtain a steady turning rate versue rudder angle relation.
The recorded:
In case there are reasons to expect the ship to be dyntiically unstable, or only marginally stable, a direct spiral test will give This is a additional information. time consuming test to perfom, especially for large and slow ships. The test is very sensitive to Also a weather conditions. 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.
(a)
following
Before (1) (2) (3) (4) (5)
Ship’s s~eds most unfavorable to directional stability at trial draft should be esttiated and Since this s~cified for the test. 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.
(b)
During (1) (2)
data
starting
should
be
the test:
Time of test and base course. Ship awed and corres~nding RPM. Wind velocity and direction. Depth of water and sea condition. Trial draft. the test: Rudder angle. 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.
With the ship in the spcified trial ballast condition and proceeding ahead at the designated sped and on a steady course, u~ing either steering ~wer unit, conduct the maneuver ae follows:
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
Lay the rudder 20 degrees to starboard and hold until the turning rate becomes steady.
33
The ship
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.
to approach
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 necessary e~ipment is a properly calibrated rate of the turn indicator and an accurate rudder Accuracy can be angle indicator. 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.
The recorded: (a)
(2) (3) (4) (5) (b)
Points on the curve of yaw rate versus rudder angle may be recorded in any order using the reverse spiral test techni~e.
following
Before (1)
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.
The procedure for obtaining pint of the curve should be ae follows:
is made
the desired rate Of turn, by apelyin9 a moderate rudder angle. 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.
data
starting
should
be
the test:
Time of test and base course Ship sped and corresponding RPM Wind velocity and direction Depth of water and eea condition Trial drafts
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.
a
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 i
3: 13.1
THRUSTER
(2)
3 .13.2
TESTS
Bow Thruster
Compass nearest seconds
readings to degree every
(3)
Depth of water condition
(4)
Wind
(5)
Trial
Other
speed
10
and sea
and direction
drafts
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.
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.
3. 13.3
special
Thruster
Tests
With the ship in trial ballast condition, conduct the It ehould be noted maneuvers below. that reduced thrust may result unless submergence of the thruster axis of at least 0.S times the thruster dimeter is provided.
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.
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 are exceptionally smooth.
The following tests conducted and data ehould recorded: (1)
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: (1)
Time of test and base course
35
may be be
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
(c)
(2)
from left 30 degrees to the right of the original heading.
(c)
RPM, tor~e, and significant prime mover par-eters at freqent intervals during the maneuver.
Repeat (1 ) (a) and (b) above, using full rudder without the thruster.
(d)
Time of issuing
(e)
Time when propeller prior to reversal.
(f)
Time shaft starte astern or the propeller pitch is positioned for astern way.
(9)
Time to stop in-Water” .
(h)
Time to reach re~ired astern shaft RPM.
(i)
Ship-s position at suitable intervals from radiometric ewi~ent, if installed, so that 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.
(k)
Oepth of water condition.
and
(1)
Wind
and velocity.
(m)
Ship’s
Ship moving ahead at shaft RPM corresponding to 6 knots: Re~at maneuvers in (1 ) (a ) through (c ) above.
(3)
Ship speeds knots:
above
6
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 ASTERN (STOPPING TESTS)
TO
With the ship at trial drafts and proceeding ahead at maxtium trial shaft RPM and nomal machinery 0Fratin9 condition, signal “FU1l Astern” 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.
Time
of test
(b)
Prime mover parmeters immediately prior to “Full Astern” signal.
ship
direction
order.
stops
“Dead-
maximum
sea
drafte.
For the pur~se of obtaining o~rat ing data, additional etopping tests may be conducted from other initial speds and using other stopping aids such as rudder cycling, as agreed.
The following data should be recorded on data sheets like Fi~re 14 during the test: (a)
aster”
and base course.
36
3.15
QUICK AWEAD
RS~RSAL
FROM ASTERN
3.16
TO
NOTE :
With the ship in the trial ballast condition and moving astern at maximum specified RPM, signal ‘-Full Ahead” while maintaining rudder in the aidship’ s position. Reverse throttle at maximum When the ship has allowable rate. gained headway, continue with scheduled tests. .
Time
(b)
Prime mover paraeters immediately prior to “Full Ahead’, signal. Monitor maximum excursions of RPM and tor~e, if available, during the maneuver.
of test and base course.
(c)
Time
(d)
Time to stop ship “Dead- in-Water. ”
(e)
Ship, s ~sition at suitable intervals from radiometric e~i~ent, if installed, so that a diagrm of the reversal maneuver may be plotted.
shaft
starts
ahead.
(f)
Time tO come to ful 1 ahead shaft RPM.
(9)
Depth of water condition.
and sea
(h)
Wind
and velocity.
NOTE:
direction
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:
The following data should be (See recorded during the test: Figure 14 for data sheets. ) (a)
LOW SPEED CONTROLLABILITY MANEWRS
(a)
Lay the rudder to 10 degrees and hold for 30 seconds.
(b)
Move the rudder to 10 degrees L and hold for 30 seconds.
(c)
Move the rudder to O degrees and hold for 30 seconds.
(d)
Return adjust rudder
(e)
Lay the rudder to 35 degrees and hold for 30 seconds.
(f)
Move the rudder to 35 degrees L and hold for 30 seconds.
(9)
Move the rudder to O degrees and hold for 30 seconds.
(h)
Return adjust
R
to the base course and eped to 6 knots with at O.
to base course to next sped.
R
and
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.
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.
The following data recorded on Figure 15: (a)
Before (1)
37
starting
should
be
the test:
Time of test and base course.
(b)
3.17
(2)
Ship speed and corresponding RPM.
(3)
Wind velocity direction.
(4)
Depth of water condition.
(5)
Trial aft.
During
draft,
(a) Test procedure windlass:
and
(1)
and sea 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).
test: Time to shift rudder, i.e. , start and stop of actual rudder motion.
(2)
Time each
(3)
Max imum heading change from base course.
rudder is held at position.
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
Lower one anchor to just below the waters edge under control of the windlass.
fore and
(1)
wINDLASS
A maximum limit to the depth of water in which the test may be conducted should be h~aed in the If the ability interest of safety. 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.
3s
for forward
(2)
Set handbrake and disengage wildcat.
(3)
Lower the anchor under control of the handbrake stopping approximately every 15 fathoms unt i1 design handbrake requirements are met.
(4)
Repat steps and (3 ) with anchor.
(l), (2), other
(5)
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.
(6)
Repeat step (5 ) fOr other anchor, except leave wildcat engaged.
(7)
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 :
Restore power and adjust to maximum dual hoist paition.
(9)
Hoist both anchors simultaneously to just below the waters edge at maximum design sped.
(b)
See Figure
(2)
Windlaee motor volts and m~res or etea supply and exhauet preseurea.
(3)
Length of chain in water at brake stops, and verification that anchor did not bottom.
for stern
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 SYSTEMS
AUXILIARY
Dockside conditions are often not 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 often are in this category:
Data to be recorded: Chain
occurrence.
17 for a data
(c) Test procedures windlass:
House anchora individually and secure.
(1)
Any unusual
sheet.
This step does not apply to stem windlasses.
(8)
(lo)
(4)
sped.
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
trials . Where calibration or adjustments at sea are necessary, it is generally advantageous to have the services of the manufacturer, s representative. 3.23
DYNAMIC
(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:
Provision of greater than natural loads or operation of e~iPMent9 under abnormal conditions An example should not be rewired. is operating the heaters in the ventilation system in the sumer. 3.21
E~RGEN:Y
NAVIGATION
SYSTEM
(1)
Navigational inputs as LON and SATNAV Global Positioning System (GPS ) .
(2)
Gyrocompass.
(3)
Wind speed direction.
(4)
Doppler
such
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 operation is im~ssible or it is desired to check speed or maneuverability under emergency propulsion. 3.22
POSITIONING
(b)
and
speed
log.
The maneuvering functions include the following:
may
(1)
Shaft
RPM.
(2)
Pro~ller
(3)
Rudder
(4)
Maneuvering thruster (s) force magnitude and direction.
(5)
Clutch
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 dockside prior to departure and any additional calibration or adjuetmentB neceseary, prfomed during the initial phases of the sea
40
pitch.
angle.
engage-disengage.
*
(c)
Other features may include incorporation of autopilot and joystick modules allowing operation in modes Buch as the following: (1)
.
.
. (2)
(3)
(4)
(d)
With automatic ship speed control, at varied headings and speeds. Without automatic ship speed control, at varied headings and epeeda.
Autopilot - Automatic control of the ships heading, with and without automatic ship speed control, and with and without active wind compensation.
With automatic tracking, with and without automatic ship speed control, at varied speeds and headings (crab angles) .
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 Operatorselectable ship heading and trackline (crab angle) with and without automat ic Bhip epeed control.
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)
41
(2)
Operation in automatic maneuver ing mode (station-keeping) with and without automatic wind compensation at varied headings for 1 hour.
(3)
Operation in joystick manual mode for 30 minutee with various cotiinations of machinery plant controlled functions “on” and “off”.
(4)
Owration in joystick automatic heading mode for 30 minutes with various cotiinations of machinery plant controlled functions “on” and “off”.
(5)
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.
4.0
4.1
STANDARDIZATION
4. 3.1
PURPOSE
Standardization trials comprise a systematic eeries of runs over a measured distance to establish 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)
To fulfill contractual obligations.
(b)
To obtain ~rformance data on full-eize ships to be used in the design of subee~ent veesels.
(c)
GENE-
4. 3.2
for
P~
4.3.3
Radiometric
Ranaes
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
TRIM
Ranaes
The develowent of radio position 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.
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 The constant shaft horsepower. observed s~eda, ~wera, and RPM are averaged for each sped point. 4.3
Fixed
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 may be initiated and terminated by observation of shore stations from the ship or via telemetry by observation of the ship from shore stations.
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 service condition.
4.2
TRI~S
WIND AND SEA
-A The effect of wind on standardization can be very serious and should be considered carefully The effect in conducting a trial. of wind varies widely with the wind
Considerations in selecting the trial area for sped runs are method of distance measuraent, depth of water and accessibility to builder’ s shipyard.
42
4.5
direction and duration, the type of ship, its speed, and other conditions. It is greatest fOr comparatively slow vessels having high bulky superstructures relative For to the underwater body. exmple, a high-sided shallow draft ship will be more affected by wind than a deeply laden seagoing tanker.
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.
4.6
Furthermore, many ships reqire helm to counteract the aerodynamic effect of the wind. This causes increased drag which cannot be eliminated by any of the customary methods of analysis.
COURSE
SELECTION
The courses for fixed ranges are established by navigation charts of the trial area.
allows
The use of radiometric a choice of courses.
ranges The
tYP and range of radiometric e~ipent and location of fixed stations 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 to take account of sea and wind conditions if necessary. If sea or wind are considerable, they should be taken on the ~arter.
Max imum True Wind s~ed ship chip
POINTS
The selection of the courses for standardization runs depends on of measuring ranges used. the t~
In view of the foregoing uncertainties, standardization data should not be considered valid unless true wind speda are less than the following:
High Power, hea~ Large, passenger Smaller ships
OF SPEED
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 calculated values 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 ship versus 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.
The direction of the wind course is also an relative to the The lightest important factor. 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.
TvDe of ShiD
NUMBER
25 Knots 20 roots 15 Knots
43
For radiometric ranges, if the first run at a speed point is aborted, another run may be immediately initiated on the sae Whether using fixed ranges heading. 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 a straight 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 a nominal 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
I , “,,,
TURN
R1OH1 TURN USINO 10. RuDDER
+ 3 + “,LES
RuDDER - HEAOING CHANGE SHOULO BE A0JU81ED TO SUIT TuRNING CHARACTER 19T1CS VITH 10. RuDDER
FIG. 3, TYPIC-
STAND~IZATION
COURSE
It is essential that the shaft RPM be steadied prior to entering Throttle and the measured course. machinery operating conditions should not be adjusted during the run. However, to shorten the aPProach run at low speeds it is permissible to increase the power on the turns provided the Wwer is decreased promptly when the ship has When radiometr ic straightened away. 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.
(c)
Average propeller tor~e if torsiometer ie installed; if not, see Section 2.0 for means for determining shaft horsepower.
(d)
Sufficient data to determine the displacement and trim of the ship.
(e)
Clock time at start of each run over the measured distance to identify run and for use in the trial analysis.
(f)
Ship’s heading for each run over the measured distance.
(9)
A record of any unusually large rudder angles used on the measured distance or on the straight approach to it.
4.8
(h)
The approximate side and direction of waves on each run.
(i)
Wind sped each run.
(j)
Current conditions from current tables or from other obaervatione euch as buoy ~sitione, for each run.
(k)
Depth
(1)
Temperature and density of water in the Standardization Area.
DATA RSQUIRSWNTS See Figure
21 for a Data
Sheet. The following data should recorded during standardization trials:
be
(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.
and direction
of water
for each
for
run.
4.9
ORGANIZATION
OF OBSER~RS
The organization personnel involved in standardization trials (a)
(d)
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 The density of small boat. the water in which the ship is floating should be measured to convert these drafts to Obtaining displacement. 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 determinant ion and the standardization runs should be applied to determine true displacement for each run.
(e).
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.
(f)
Ship’ e heading should be taken from the bridge compass.
(9)
The size and direction of the waves for each run should be obtained from an expr ienced bridge observer.
(h)
Wind spsed and direction should be obtained with an anemometer and wind direct ion indicator.
Bhould:
Provide for simultaneous recording of data. Provide for prompt correlation and analysis of data at the end of each run.
(c)
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.
(d)
Provide for clearly defined responsibilities with a single person in charge of run select ion and acceptance.
4.10
INSTRU~NTATION sTAND~ IZATION
FOR 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.
(b)
Average propeller tOrque should be determined from a torsiometer. If a torsionmeter is not installed, see Section 2.0 for means of determining shaft horsepower.
of the
(b)
(a)
(c)
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. 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.
46
(i)
4.11
4.12
Depth of water over the measured distance may be obtained from the ship’ s sounding e~ipment or may be taken from published data. COORDINATION
AND LIMITS
The acceptable tolerances and limits for standardization trials are provided by Figure 4.
PROCEDURE
(a)
check that RPM is correct and propulsion plant is steady.
(b)
Check that course is correct and area is free of traffic.
(c)
Check
tor~e
(d)
Check for zero acceleration radiometric device is being used.
(e)
Give
(f)
Give “mark” the run.
(9)
Monitor data deviation.
(h)
Give
(i)
Give “mark” run ...
(])
Evaluate results of the run and announce the next run.
(k)
Alter turn.
(1)
Make turn to reciprocal course.
“standby
is steady.
heading
0.25%
Difference in tOtal revolutions from separate revolution counters for a run
0.20%
Differerice in RPM fOr each run from mean for each speed PO int
2.0 %
Difference in RPM of any shaft of a multiscrew ship from the mean for a run provided the rated RPM for all shafts is the sme
2.0 0
4.13
of
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.
signals. ”
signal
Difference in time by separate timing devices for a run
FIG. 4, STANDARDIZATION TRIAL TOLEWCES AND LIMITS
to start
for evidence
“standby
if
signals. ”
signal
Tolerance or Limit
~
The following procedures may be used as a guide to give satisfactory coordination of a For this standardization run. se~ence it is aeeumed that the ship is in the standardization area and on the approach leg for a standardization run:
that
TOLERANCES
to end the
for leg toward
Data from separate observations should be plotted separately. I f 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 The RPM, SHP tabulated and plotted. and speed for each speed point should be obtained by averaging the data from the two runs in opposite If three runs are used, directions. 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
If recommended trial conditions 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.
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.
48
5.0
5.1 5. 1.1
INSTRU~NTS
ANO APPARATUS
FOR SHIP ‘S TRIALS
peculiar to sea trials, a more extensive coverage is provided.
GENERAL Introduction
5.1.2 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 The instrument type, acceptability. precision and the sea trial instrument plan beyond the ship’s instrumentation should be specified Instruments should in the contract. be selected on the basis of ship system performance re~irements and on the basis of the conse~ential coot for departures from ship If the systems target performance. contract and specifications are silent, it is essential that the shipbuilder prepare a suitable sea trial instrumentation proposal and It is calibration procedure. 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.
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 the capabilities 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.
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, ie discussed 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
49
(a)
General Instructions, Performance Test Code, Fairfield, N.J. , The tierican Society 0 f Mechanical Engineers, PTC 1 - 1986
(b)
code on Definitions and Values, Performance Test Code, Fairfield, N.J. , The Werican Society of Mechanical Engineers, PTC 2 - 1980 (R1985)
(c)
Temperature Measurement Performance Test Code, Fairfield, N.J. , The
Werican Society of Mechanical Engineers, PTC 19.3 - 1974 (R1986) (d)
Guidance for Evaluation of 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 of Fluid Meters: Interti Supplement on Instrment and Apparatus, Fairfield, N.J. , The herican Society of Mechanical Engineers, PTC 19.5 - 1972
(h)
(i)
Sean, Howard S. , Fluid Meters - Their Theory and Application, 6th edit ion, New York, The tierican Society of Mechanical Engineers, 1971 Miller, R. W., F1OW Measurement Engineering Handbook, New York, McGraw-Hill Book Co. , 1983
50
(])
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 Code for 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
(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
(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
(s)
Machinery Vibration Measurements, Jersey City, N.J. , The Society of Naval Architects and Marine Engineers, 1976, Book No. C-4
(Y)
Design of DissolvedOxygen Testing Cabinet, U.S. Naval Engineering Experiment Station, February 29, 1940, Re~rt No. B-1158
(t)
Acceptable Vibration of Marine Stem and Gas Turbine Main and Auxiliary Machinery Plants, Jersey City, N. J., The Society of Naval Architects and Marine Engineers, 1976, Book No. C-5
(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) (u)
Ship Vibration and Noise Guidelines, Jersey City, N. J., The Society of Naval Architects and Marine Engineers, 1980, Book No. 2-25
Standard Test Methods for Dissolved Oxygen in Water, Philadelphia, PA, herican Society for Testing and Materials, ASTM Designation DB8B-B7
(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
(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)
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)
Naval publications are available from the Comanding Officer, Naval Publications and Forms center, Attn: Code 106, 5801 Tabor Avenue, Philadelphia, PA 19120-5009. ASTM publications are available from The herican Society for Testing and Materials, 1916 Race Street, Philadelphia, PA 19103.
(ad)
Flue and Exhaust Gas Analysis, Performance Test Code, Fairfield, N. J., The berican Society of Mechanical Engineers, PTC 19.10 1981
5.2
(se)
(af)
5.2.1
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, SNAMS Fairfield, N.J. 07007-2350. 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
TvDes
MEASUREMENTS
of Instruments
Five types of instruments comonly used for temperature measurement. These are:
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
(&g)
TEMPERATURE
Thermowells and TemDorary Installations
Most permanent installations have the temperature measuring devices installed in a thermowell which is hersed in the fluid whose Due te,m~rature is to be measured. 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 t hemometers 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 Securing precision is not rewired. 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 The recommended procedure involved. 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 t hermowe 11. The thermocouple should be in solid contact with the bottom of the thermowell and for high temperatures should be packed with a A thermocouple suitable material. 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 Where high preseures are fluid. involved, a thermowell is the safest installation. 5.2.3
AdaDters
for Seneina
5 .2.5
Instrument
and Sea Trials
It is recommended that the ship, 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 le during 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 For tube, bellows or diaphram. these, pressure is transmitted to an elastic me~er and the resultant motion displayed using a suitable scale.
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
Calibration
Compatibility
Temperature MeaSuring instrumentation should be compatible with the pressure and tem~rature in the system in which it ie to be used.
The following ty~s are readily avail~le from reliable makers: (a)
53
Bourdon typ gages - The most comon preseure measuring devices for vacuum, low, medium and high pressure.
(b)
Transducers - Convert pressure into pneumatic or electrical signals. They are utilized for remote eensing, particularly on automated ships.
(c)
Bellows gages - Utilized for mea9uring low pressure differentials up to 50 PSI.
(d)
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.
(e)
Deadweight gages Installed for trials where great accuracy is re~ired. They can be used only for systems without major pressure fluctuations.
loop seals to establish a known water leg. Means of venting gage lines 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 The gage should be temperature. 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
(f)
5.3.2
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 This information on the data sheet. should be so noted at the gage also. For installation and procedural steps to avoid water-leg error see reference (e) .
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.
Proner Connections PrOtectiOq
Zero Adiust
and
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
54
5. 3.4
Calibration
and Sea Trials
Li~ids of different specific gravities may be uBed, the most comon are: oils of various specific gravities, mercury and water. It is important 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.
It 1S recommended that the ship 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
COIUMnS should be mounted vertically. The u8e of inclined gages at sea is not advised as they are affected too much by the motion of the ship.
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, Either type, if and mercury column. 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 When an absolute pressure Station. gage is used, no barometer correction is necessary. See paragraph 5.3.9. 5.3.6
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 Measurement
Manometers
Manometers, also bom as Utube 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.
For Flow
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 or near 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
the installation, and calibration procedures for each. 5.4 5 .4.1
Absolute
Gaae
Pressure
5.4.2
Gaaes
Further
Positive ~
Displacement
Flow
(a)
Meters should be mounted in the horizontal psition.
(b)
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.
(c)
Meters should be installed and back pressure maintained that they will be kept filled with li~id at all times. This is
From
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
of Instruments
A positive displacement flow meter may be of either the rotating Prior to disk or piston type. 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 Unless specified, post sea trials. 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:
These gages are special mercury columns with one end evacuated and sealed, so that the gage may be used directly to measure See reference absolute pressure. (f). They are very useful for measuring condenser preesures and may replace an opn-end mercury column and barometer. 5.3.11 Gaae Protection Pressure Pulsation
Tvpee
During sea trials, flow may be measured by positive displacement meters, turbine meters, variable area meters, metering flow nozzles, orifices or venturi tubes.
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
FLOW WASU~~NTS
Information
Reference (f ) provides a complete description of the t~s of pressure measuring instrumental ion,
56
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. .
(d)
determination. This reqires precise temperature measurement of the fluid in the line connected to the meter. Upstrem fluid temperature is preferred.
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.
(e)
If a control valve is used, it is preferable to locate it on the discharge side of the meter.
(f)
Meter should be used to measure only the limids for which it was designed.
(9)
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.
(h)
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)
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.
(k)
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 Prec i8e Measurement 8
For
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
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.
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
5.5
5. 5.1
HorseDower Indirectly
Determined
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 steto 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.
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
TORQUE AND HORSEPO~R ~ASURS~NTS
For methods of determining horsepower which do not involve direct measurement of tor~e, consult references (k) , (1) , (m) , (n), (o) and (p).
Indicating and Recordinq Mechanism for Orifice Plate. Flow Nozzle, and Venturi Tube
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 Such tor~e and RPM signals. systems are valuable for trend studies of ship operation but can lack precision, convenient cal ibrat ion and zero setting
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,
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.
observed in making a selection of trial meters to provide data for demonstration of power or fuel rate contractual requirements:
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
(a)
Inherent accuracy should be better than design margins.
(b)
Zero tor~e meter readings should be determinable during shaft calibration and at sea.
(c)
Meter should be suitable for taking shaft calibration readings.
(d)
All components should be sufficiently rugged and provided with sufficient protection to operate indefinitely in the adverse environment usual for ship installations.
(e)
Meter should be capable of operating on the ~ality of electrical pwer available on ships.
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.
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 the sea trial torsiometers. shipboard meter may be used as the sea trial meter when the owner and contractor agree during their sea See reference (p) . trial planning.
Torsiometers differ chiefly in the method of gaging torsional deflection. The following typs are available:’ Variable mutual- inductance gages Resistance-wire strain gages Acoustic-wire strain gages Phase-shift gages Permeability-magnet ic Technical
endorsement
of any
tYPe Or make of torsiometer is contrary to Society Wlicy; however, the following guidelines should be
59
5.7 5.7.1
SHAFT
THRUST~TERS
Purpose
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.
of Thrustmeter
A thrustmeter is an instrument for ensuring the thrust developed by the propeller in the axial direction By cotiining the of the shafting. 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
5.8 5 .8.1
(b)
Hydraulic cells.
(c)
Strain
pressure
gage
Propeller
~ASURE~NTS Revolution
Counters
Electric countere located in the computing room, shifted either locally or from range observation stations, can be used to obtain When total revolutions for a run. 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 When not at andardiz ing, next run. the electric counter may be shifted The by the trial signal system. ship’s counter should also be read on the sme interval as the electric counter to obtain accurate backup data.
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: Defamation of an elastic meber.
SPEED
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.
of Instrument@
(a)
SHAFT
in
load cells.
60
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 such cases the vibrating-reed frevency indicator may be used. Care must be taken to avoid reading harmonics of the fundamental speed.
For trials that do not include standardization 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. .
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.
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 SDeed Indicators
5.8.3
and
Additional
Information
For further details about tywe Of instruments and precautions for their use to measure shaft speed see reference (q) .
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.
5.9 5.9.1
VIBRATION Oerview AnalvBis
~ASU~~NTS of Measurement
and
Vibration measurement and SpCtrum analySiS Syetems vary with They their functional application. may be adapted for measurement of hull 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
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.
.. 01
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.
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 Or integrate the signal to provide an output proportional to displacement, velocity or acceleration, as The total output may be selected. 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. The Bands may be wide or narrow. selection of these features is dependent on contractual re~irements, the e~ipment available, and the circumstances The time and personnel encountered. available must be considered. Portability of e~ipment is also a major consideration. 5.9.2
Emipment
5 .9.4
5.9.5
Vibration
Data Collection
Good practices for obtaining vibration measurements include the following:
For Sea Trials
appears excessive to the physical senses; 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. StOrina
Em iument
Vibration pickups, mplif iers, and data analysis and readout eviPment are available in compatible 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.
In general, electronic data and analyeis thereof is not reqired unless the vibration encountered
5.9.3
Compatible
Data
The practice of magnetic taping vibration signals or filing them in a data base for pssible
62
(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
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 is important to use instruments which provide data to meet shipbuilding contract re~irementa.
to understanding and interpreting the data. (4)
5.9.6
Mark the event rime, RPM signals, time, and calibration lines traced on the charts to correlate vibration data with interpretive information.
Additional
Information
5 .10.3
Storina
Airborne
Noise Data
For further information on vibration measurement techni~e, e~ipment and analysis, cone”lt references (r), (s), (t), (u) and (v) and the manufacturer’s literature.
Varioue methods can be utilized to save data for later analysis as described above for vibration measurements.
5.10
The good practices recommended for vibration measurement are also pertinent to sound measurement.
AIRBORNE
5. 10.1 Purw Measurements
5 .10.4
NOISE ~ASURE~NTS se of Sea Trial
5 .10.5 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
Data Collection
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 5. 11.1
E~iment
FEEOWATER
TESTING
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
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
63
appropriate 5. 11.2
data
sheet
Measurement ~
in section
6.
also sufficiently accurate for checking 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.
of Dissolved
The oxvaen content of . . feedwater is usually determined by the Winkler Method as this test is the most convenient and meet likely The to give the accuracy desired.
5.12
5.13 5. 13.1
Continuous monitoring of feedwater oxygen content may be performed using an electronic These instruments are instrument. commercially available, and more detailed information concerning capabilities may be obtained from manufacturers.
LEMGE
MEASUREMENTS
Measurina
Gases
Air and noncondensable gases drawn 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 are described below. 5. 13.2
Rotometer
Salinity One type, a rotometer, omrates by the flow of gas vertically 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.
Low salinity in the condensate and feedwater is an indication of a tight syetem, i.e. , free from Salinity in-leakage of sea water. should be read at various Pints in these systems and recorded in the aPPrOPr iate data
5.11.4
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) .
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).
5. 11.3
DENSITY
sheet
Measurement
in Section
6.
of Salinity
5.13.3
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
Orif ice-Rotometer
A second t~, an orificerotometer 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
5 .13.6
5.14 5. 14.1
FLUE AND EX~UST-GAS
ANALYSES
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.
‘Orif ice-Manometer
Ultrasonic
Information
More details of various models and their uses may be obtained from epipment manufacturers.
A third type, an orificemonometer 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
Additional
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.
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. The detectors electronically convert the probe output into audible sound in the attached earphones and drives a ~inter on a meter.
In the bubbling type of pi~tte, the gas smple enters the bottom of the piwtte and the saple bubbles up through the chemical Filler material for reagent. 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 The displaced displaced by the gas.
65
analysis. There is no single correct method of s~pling which is One applicable in all cases. 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.
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) .
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 tubes are 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 in feriOr fOr service and functional reasons.
The following absorbing reagents are used in the pipettes C02 pipette - Potassium hydroxide solution 02 Pipette - Alkaline solution of pyrogallic acid CO pipette - Acid solution of Cuprous chloride The best results are obtained when these solutione are prepared Full immediately prior to testing. descriptions of the methode for preparing the solutions are stated in reference (ad) .
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.
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 forced into 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 represent at ive saple from a stratified gas strea is the greatest cause of error in gas
a
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
5.15
Manual and Automatic TvDes of Flue Gas Analvzer9
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
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 Instrument efficiency. manufacturers need to be consulted for details regarding gas. s-pling re~irements and measurement data available on various instruments for the epecific flue gasee exhausting from the ship.
5 .17.1
ELECTRICAL
~ASU~MENTS
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.
The shipbuilder and owner may agree to use ship installed flue and exhaust gas analyzers to collect e~i~ent PKfO~anCe data during the conduct of sea trials. The sea trial plan should s~cify the analyzers to be used, when they are to be used, and the approved methods for analyzer calibration. Additional
AND PURITY
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) .
There are a variety of manual and automatic types of gas analyzers available as portable or ship These kinds of installed e~ipment. instrumentation are valuable for determining e~ipment performance and the content of exhaust gases which enEer the environment. see reference (ac ) for further information about measuring particulate matter in a gas strem.
5 .14.3
STEW QUALITY ~ASU~~NTS
Information 5.17.2
For more in fomat ion see reference (ad) and contact manufacturers of e~i~ent.
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
5. 18.3
5. 18.1
WIND SPEED ~ASURSMNTS
Information
AND DIRSCTION
CUD Anemometer
Wind speed is measured usually by a cup anemometer which gives aPParent or relative wind speed. Apparent wind speed occurs by cotiining ship, s velocity and true wind velocity. Any instrument which measures wind speed may be used to measure apparent wind speed.
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
5. 18.2
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.
Electrical measuring instruments and testing apparatus are covered in detail by reference (k). 5.18
Sir=
Oirect-Readina
Anemometer
Indicators 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 directreading anemometer.
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 by dividing the counter reading by the elapsed time across the course. Another ty~ of instrment indicates aPParent wind roped instantaneously and continuously and re~ires no timing. This type of indicator is recommended because of the convenience in obtaining readings from it.
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 in studying 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.
basic principle of meaeuring phase delay of t“o signals. 5 .19.2
5. 18.6
Wind
Direction
Indicator
Combination
Indicators
Cofiination wind indicators They cotiine are available. readings of direction and speed, and they are more convenient for sea trial purposes than the separate They utilize a contact indicators. type synchro transmitter to transmit wind speed and direction to a dial readout. 5.18. a
The position of the ship can be 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.
Locat ina Sensors
The sensors for all wind direction and velocity measuring e~ iPment should be located high enough 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 5. 19.1
RADIO~TRIC Tvues
T~CKING
Half
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 is calculated for the frequencies in use and based on the empirically accepted velocity of propagation, the lane counter readings can be converted to distancee.
A wind-direction indicating system, which continuously indicates the apparent wind direction relative to the ship, is recommended for sea This system will consist of trials. a remote transmitter and an indicating unit. 5. 18.7
PrinciDle of Meas”rinq Wave Lenuths
the
SYSTEMS
of Devices
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.
‘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
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 the Also, ship, s radiometric e~ipment. lane counters must be thus reset if the lane count is loet by power or e~ipment failure, maloperation or a HOweveS, severe electrical storm. 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
5 .20.1
Siahtina
of Instruments
The following types of timing instruments may be used for trial data: (a)
Ship’s
Clocke
(b)
Stop Watches
(c)
Electric Clocks
(d)
Chronographs
Timers
and
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. I f a prmanent record is desired, a printer can be connected to the read-out instrument. 5. 19.4
TvDes
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.
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.
5.20.4
Electric
Timers
and Clocks
Electric ttiers may have a synchronous motor drive and depend upan the ship- s ~wer fre~ency fOr
70
timers may replace electric timers to maintain standard item, if shipboard power frequency is not constant or is uncertain.
accuracy. Electric stop clocks with accuracy controlled by quartz crystals are available with dials readable to one one-hundredth of a second. Special timers may be designed and used where desirable. They may have a master clock with accuracy controlled by a qartz When electric time crystal design. measuring devices dependent on ship’s power are used for sea trials, caution should be exercised to maintain ship’s generator fre~ency at 60 CPS. Electronic
5 .20.5
Recorders
Recording instruments should be inspected regularly to see that the paper-driving mechanism and paper marking device operate properly to provide correct time indications.
71
6.0
6.1
TRIAL
DATA AND ~PORT
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 data pertains. 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.
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 the completion of trials. 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 Copies of raw data graphic forms. sheets, if legible and interpretable, may be used for Raw data directly reprted 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.
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 the shipbuilder to study the guide, the contract, and the ship’ s apcifications, 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
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.
72
the report. Such plots are indicative rather than definitive of the ship, s turning characteristics and need not be corrected for drift.
a Pr0ce9s fOr making data available to authorized parties aboardship. Data forms should distinguish between data from special sea trial instruments and data from ship’s instruments.
6.5 6.3
DATA C~W
MANE~RING TESTS
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.
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 be made. Training should include familiarization with the data forms so that entries will be made in the correct column, and the instrumentation 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
STANDARDIZATION
TRAINING
TRIALS
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.
AND SPECIAL
Figures 5 through 19 have been developd to assist the shipbuilder in preparing data t abulat 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.
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
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
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 If recalibration of re jetted. ship, s instrumentation is accomplished prior to ship delivery, note of such recalibration should be included on the applicable data eheets.
(6) (7) (8) (9)
Figure 26 reflects the recommended content for reporting operating data for a typical stea turbine powered ship and main ..propulsion diesel and gas turbine Resulte of the boiler installation. overload test should be performed as indicated in the boiler section.
(lo) (11)
(12)
(13) 6,8
TRI=
~PORT
The contractor should prepare a trial report with recommended content as follows: 6. 8.1
(14)
Introduct ion (c)
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 (a)
(b)
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.
(1) (2) (d)
Type of ship Exaple: Single- 6crew, stem-turbine driven, cotiinat ion bulk and general cargo ship.
(e)
(1) (2)
Characteristics
(3) (4) (5)
Length overal 1 Length between pr~ndiculars Be a, maximum molded Depth to main deck at e ide, minimum molded Draft, full load, molded
(4)
●
74
and displacement*
Light ship Fuel oil Fresh water General cargo Refrigerated cargo Liw id cargo Total cargo deadweight Tot al deadweight at ful 1 load draft
Capacit ice*
(3) (1) (2)
Officers and crew Passengers
Deadweight (1) (2) (3) (4) (5) (6) (7) (8)
Shim’ s Characteristics
Principal
Complement
General cargo bale cubic Refrigerated cargo net cubic Convert ible 1i~ id cargo net cubic Non-convertible li~id cargo net cubic May req ire additional breakdown dependent on ty~ of cargo carried.
(f)
Hull
characteristics
(1) (2) (3)
(4) (5) (9)
Rudder (1) (2)
(h)
Prismatic coefficient Midship coefficient Bulk as percent of underwater profile area at full load draft Type of bow Type of stern
(2) (3) (4) (5)
(6) ●
Principal personnel present on trials, including representatives of the owner, acceptance authorities, regulator bodies and shipbuilder.
(c)
Trial
ballast
(d)
Trial
results:
(1)
Maneuvering trials and special tests. See Figures 5 through 20. Standardization trials. See Figure 21. Fuel economy tests. See Figures 22, 23, and 24. Stem rate test. See Figure 25. Propulsion plant data. See Figure 26.
Nutier and type Rudder aB ~rcent of underwater lateral profile area at full load draft
(2) (3)
characteristics*
(4)
TY@ including direction of ahead rotation and nutier of blades Dimeter Pitch Expanded area ratio RPM at full load draft and registered horsepower Des ign submergence
(5)
Include data propeller
6.S.4
for each
EW i~ent (1) (2 ) (3)
6.B.3 (a)
Trial
identification
Other
Data
(a)
Nufier of days between trials and meet recent drydocking.
(b)
Wind
(c)
Sea
6.8.5 (i)
schedule.
characteristics
Propeller (1)
(b)
direction
sea
and velocity.
etate.
ADDendices
- As Elected
data
Main propulsion machinery Imprtant auxiliaries 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.
(a)
Design heat balance diagrms.
(b)
Fuel oil analysis
(c)
Flometer
(d)
Fuel and stem curves.
(e)
General arrangement plans if they are availsble in reduced size on a single sheet.
(f)
Other available information prtinent to trials.
Data
Log of evente.
75
system
re~rt.
calibration rate
curves. correction
—— Astern
Sh tip
&head
N.me
Triel
[P
Date
Tlma
O(
Baea
Course
Depth Sea
of
unit or
s]
Unit [P.,
l$.
7 rq
Steerlnq (If
Dem -
ons Lra
s)
Ledl
Wa tar n
Wind
Direction
Wind
Velocity
Trial
Dr art
Tr]ul
Draft
[F. dl (Aft)
P.opel!e. (B. qinnlnq
RPM I
Propeller
RPM
St09rlnq Control
Station
Rudd.. ,)
(End) in
Movement b
Maximum
Tim.
Rudder
A“qles
Max.
(P
SI
A“x,
Steerlnq
Test
COnditl.
(s,.
Unit or
Steering
Steady
Motor
O-R
O -L
O -R
R-L
L -R
R -L
L -R
R -L
L -R
R -o
L -O
R -O
O -R
O -L
O -R
R -L
L -R
R -L
L -R
R -L
L -R
O -R
O -L
o -R
R -L
L -R
R-L
L -R
R -L
L -R
R -O
L -O
R-o
Amps
Maximum
Ram
a
a
Preeaure
Max. SOrv O Preee. (If Avoilabl.1 Ma. . Repl en. Press. (If Available) Max. Pump Stroke (If Available) Idle
Volta
Idl@
Amps
Idlo
RPM
Minimum
> b
Motor
R.ddar no. mal Time
Volta
a.qlas otearlnq
from
start
and .“dd.. mods and to
5
mov. msnt to activate
d.grees
FIG. s
tlmem a. dmmonstrat. emerqancg unit
b. fare
Steering
76
orderad
Tests
anqle
d. also
to
lime be
to s.. ”.. recorded.
—
“... UtPARl”
—
RE FRU” .ASE
1K6CK
,AC71C, L 0,..ETER
OF MEAOINQ
—
lN1ll
FINAL
o] Auslsn
AIE
4
,., ,,,.. ,,.,,,, ... —z—
I
,,,,
..
as ..*,.,. ,.”a, ” ,.,,,.,.. I*I...1 ..di... h.h. .“*.. . . . . . . . ., ,,..,,,
,.,.,.,
OP..
.s,,, M.,. ! ,!.,
,.,,,,.
,..,
,,
. . .
d.”
b.
” .,,,
.,
,,,,.
?
CO
.0,,.,.,,,.
.,
”, . ...”.., ,.,,.,
”. .“,. ””. ..,...’,...
1000
500 -
SC4LE IN FEE1 !..
1s..
H.. d,”q <... B... C.. ?,.
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
e.,
W,t.
r
C.”4L %1..
wind 01,. cti. Vina
NOIE: R. Pr.,, ”t.ll. ” .1 .h. uld b. , 11.. .c. l.d .P1. nt. d 1. :::hb:h~:L:,:~
lqP.
.I
th, .hl P 1“ I.”eib,
.nd I..,l. d .“ tb. y.: ,.lO.,. ”CO i,..
Tra.ki.q
n
V.l. clt”
1,1.1
O.afl
1.1.1
0.. ?1 [UT)
U.,.”.
)
(Fvol
D.,lt
C. . . ..l
..”
.1.010 k
01.1,
8*.1..:
u,. . O,p,,
Drlrt C.rr.
Radiometric
tvr,
FIG . ~ Turning Circle Test or Other Precise Tracking Available
77
f...
ct lo”:
8,.. :fi:ct
c..... le._
01.
.
r ,AC,
,CAL
.,*.E,
F”_
TRANSFER i
I
IeO” CHAUOE
OF HEADINO : : :
-—
FINAL DIAGIER
Sae -
1080
SCALE IN FEE1
m Vl”d
Direct
V1nd
V.locltu
T,lal
O-aft
1,1.1
Draft
lAFT1
to
Chang.
Adva... T.an.
Radiometric
f,r
]..
{FVD1
i.
Tactl.
al
Fl”al
Dlamel,
Cheng.
Hdq.
Hd9.
90” 90”
D1. m.t,, r
FIG. 1 Turning Circle Test or Other Precise Tracking Not Available
78
J
WIND
BASE COURSE (5) ,
t
\ ~OU
i..
-. . . .
COURSE
..
Em.
Tent Beq.n
Base co”...
>
Rudder tigle Shaft RPM (Beginning) Shaft RPM (End)
m Oe,th of Woter
/
PE
10
Elapsed fima
\
(s..)
----~.-(-z
~:
)
../-,
---
5
10
15
OECRCES Lf n
Rtider Mwment
I
RCfl
Elap-d mm (w)
H (1) Stud 10R Aft.in 10R
..(2)
Stofi
10L
Main
10L
(3) stad e“
10R 10R
(4) Stan
IOL
(5) Attain O
FIG. ~
“Z” Maneuver
79
Test
Hdq.
Sea
Condition
Wind
Trial
Di.ectfo”
Draft
[Fwdl
‘raorari
~
I
‘Aft)
Time
?udder
Anqle
lapsed
Time
— [See)
Time
FIG. ~
Initial
80
~rning
Test
ieadlnq
STABLE
SHIP
R“DDER RETuRNED TO MIDSHIPS
*
Im
-
‘1 UNSTABLE
SHIP
I
FIG. ~
Pullout
81
Test
(s.0)
“..dl”g t,.m h.. co”,,.
Svad
(K!.)
RPM
( Ship
R“dde. STARBOARD
PORT RUDDER
ANGLE
I la)
. 0
STABLE
SHIP
<
Anqle RPM
(Beqln.
Shaft
RPM
[End)
DeDLh
of
I t
I
Sheft
Sea
!
?
Name
ing)
water
I
Condlt!on
Wind
Oiroct
[on
Wind
Veloci
Lu
1. 1.1
Ora Ft
[Fwd)
T,lal
Or aft
(Aft]
i
I
*-
+1’ I
I
PORT
SIARBOARO Q“dder A“qle
?@R lSR 18R 5R 3R lR 0
Oata
for
Time (s.. .)
Step
No.
Ship Headinq
R“ddar
Angle
Change ]“ Ship Headinq
Constant 6 Conaec. Roadlnqs
for tive
Notes: A total of 6 reading8 or constant rate of heading change 1s ne. ded to cal.. lata average rate in Deq. /Sec. Thiu calculation 18 done for each stop.
FIG. Q
Spiral Test
B2
:: 5L lBL 15L 28L ISL 18L 5L 3L lL e :: 5R 10R 15R 2@R
Conslant Rate of Chanqe !. Ship Ho bdinq (0. q ./see .1
I Ship /----
,,
,’
I
. . . .
Tent
0.1.
Tim,
1..1
B.,,
course
B,q,
n
STABLE ‘SHIP
( ~. ~. . . ‘\
D.plh
i .’<_u
--
S,a
NsT4BLE SHIP
----
I Wind
-e. @ -
Wl”d
* I
I
ea
)0
PORT
STEP
Ill 10
0 RuDDER ANOLC
YAV
RATE
OEQ/SEC
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
ea STARBOARD
I
Reverse
Wal,,
condition
I
,1?..1,..
V.lo.
]t”
TFlal
Or, fl
Trial
Oralt (4f11
RuDDER ANQLE
FIG. u
of
Spiral Test
{F. d)
I
Shl P Name
1,1*
Time
O{
W]”d
01? 8.11..
Ease
Course
Wind
Velocitg
Water
Trial
Draft
[F. dl
n
Trial
Draft
[Aft]
Depth
Test
of
sea
Condltl.
Thr.
et,.
I
Date
Name
,. .,,,. s... .,. S., . . ..”..” . ..3 .,, . . ,----Iap, [Ml”
ad
3
0 Knot,
Time
8 Sec )
Th, ”,ter & Full Rudder
Thruster Onlq Hdq
Ch. nq. 1. Hdg
@
Hdg
6
Knot. R“dde.
Chang. in Hdq
Hdq
Th, ”eter & Full Rudder
Only Change
I.
Knots
Hd q
Hdg
Change
i“
Hdg
Rudde.
Hdg
Onlq Ch. nqa
1“
Hdq
0“
00
0“
0“
00
I
1
t
,
I
10 20 ,3B
3@0
a
3a0
Left
30°
Left
Le
1
1
?
~o
@“
0“
38°
30”
Lar L
L,
0“
0“
NOTES : 1, 2, 3.
a
Reve.8e
Ship
1s
10
1; .Iapnad h.adi”q. If Thru8ter at 3-knot
Thru8ta.
b.
headlnq
Into
the
wind
.1
time
tha
b.qinninq
of
each
1..1.
reaches 10 minutes prior to 30° change 1. ship t.rminat. the test at this point. IS .ffective at 6 knots. ahlp 8P.. d 1s Lo b. increased Intervals until thr”ate. 18 no longer effective.
.ndler
Shift
FIG. u
Rudder
Thruster
g4
Test
Ahead
I
to Aster” Trial
Ship
Name
Time
to
Ease
Co. ree
Test
Shaft
RPM
IBeginnlngl
Depth
of
Sea
Condltlon
I
Wind
Direction
Wind
Velocity
Trial
Draft
[Fwd)
Trial
Draft
(Aft)
Fl”al
Heading
to
Start
I
Shaft
Time
to
Ordered
Time
to
Stop
Aster.
RPM
Astern
Ship
Reach
NOTE : Also to be ,ncl”ded are max Lmum excursions of RPM, torque, steam s“pplq, turbine Inter”al and exhe”gt pressures and temperatures, or equivalent data for diesel o. qas L“rbine plants, at ?requent intervals d“rlnq maneuver.
1
Elapsed [Mln and
I 2 3 4
Time
Ahead
Water
Marker
Date
Substitute use.
Timo See)
Distance Traveled Between Markers [Feet)
plot
of
ship”8
track
if
C“m”latlve Traveled
radlometrlc
equipment
I Astern Time
of
Bass
Course
Ahead
Test
Shaft
RPM
Oepth
of
Sea
to
{Bag
innlngl
Water
Condltlon
Trial
Oraft
[Fwdl
Trial
Oraft
[Aft]
Final
Heading
Time
to
Start
Time
to
Ordernd
to
Stop
Ship
RPM
AhOad
Wind
Oirectlon
Time
Wind
Valoclty
Maximum Torque
FIG. ~
Quick
Reversal
B5
(If
Test
Shaft RPM
Available)
Ahead Ahead
Distance [Feet) is
in
Name
Trial
Date Start
Time
or
6K
5K
19R
leBt Attain
Sha?t
Eldp%ed
Ruddev Anqle
Ship
RPM
10R”
16K) Start
10L
[SK ) Attain
10La
14K) Star
L
0
[3K) Attdln Dep Lh
OF
eb
Water Start
Sea
35R
Condition Attain
Wl”d
Direction
Wl”d
Veloc!ty
Trial
Draft
(Fw6)
Trial
Draft
(Af L)
35Ra
Start
35L
At Lain Stat
Max,
Rudder Angle
Depar
——
10R
t”..
I I
I
1
!
I
I
0
Attain
E
$rom
Ease
4K
SK
6K
35La
course 3K
I
I
I
35R
t –-m
10L 35L
a.
Rudder
angle is to be held for 30 seconds before next rudder movemmnt. la to be rneiored prior to eta. ti. q tho Shig speed 35 rudder movoments. Teat 1s to be cant lnuod 1. dacrea. ing l-knot ln tervale until the rudder 1s no longer effective.
starting
b: c.
FIG. ~
Low Speed Controllability
86
Maneuver
Tests
Time 4K
(Ssc) 3K
1. I SIIIP
I
Name
Time
of
Sea
Trial!
I
Uate
Test
Condition
Wind
Dlrnct
I Trial
[on
Draft
I Minimum
(FWD)
Steady
I
Shaft
RPM
I
FIG. ~
Trial
Ship
Name
Time The
to holut raq” ired
each initial
chain
speed
Averaqe
anchor depth In
separately
feet
Time to ho let slmultaneoualy from the required Initial posltlon to water edge
Averaae
Chain depths
Slow Steaming
chain
speed
8 topped by [fathoms]
In
per
Date
Time
Began
frOM
minute
both anchors dual hoist
feet
hand
Ability
brake
per
minute
at
following
I
I
=
1
I Maximum
Readings
as
Peri
inant
volts
{
I
Water
Depth
(fathoms)
Required (one
Initial anchor)
Required (two
Inttal anchors)
Depth
Amps
Steam
or NOTE:
Hyd.
Depth
Pres8 Unusual
occurrences.
FIG. ~
hchor
if
any,
Windlass
are
Tests
to
be
reco?
dad.
DISTILLING
PLANT TESTS
Users should develop their Own format for reporting the results of this However, the following test, depending upon the e~ipment available. information should be recorded from the ship’s instruments for each distilling plant.
Prior to demonstrating control devices including:
distilling
plant
performance
check
safety
and
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 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 Salt
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. 2.
The above data list should be adapted for the typ of distilling plant installed. 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 88
Plant Tests
Ship
Name
Mode
of
lT.ial
I
Date
Positioning
Up Oration
Time
Start
Time
Complete
Ship
Location
Oepth Sea
of
I
I
I
I
I
Water
Conditfon
W1”d
D1. ectio”
I
I
I
Wl”d
Velocity
I
I
I
Tide/
C”r.
Tldo
/Currant
I
I
I
II
1
I
I
I
I
I
I
ent
Voloclty
Ship6
Headl”g
Shlpe
Speed
Shaft
RPM
PPo Deller Rudder
O1rectio.
A“qla Force
Thruster(s)
D1. eetio”
of
Fe at.,.,
I
Pitch
Thr”ster{el
Loq
{
Operations Oemo”stratod
and
FIG. B
Dyn-ic
Positioning
89
Sy6tm
Tests
SR, P
sea
N...
Tr,
stat,
Stop .an.
control
U.ne.
0.1.
SL.
AI.
H.edi”g
Shl PS
centralized
al
I
vers
to Maxlm”m Ahead [etoppl”q ”.evlnq @peed p.8it10”1
.1
Po,
Tempe.
rt
al”re
OF/°
C
Shari
llio”
O.de.
11..
Respona. [s..
ed
RPM 11.. )
I
each
I
I
I uaxlm”m mane”
Ahead ve.
to Slop (slop pinq Epeod posit ionl
lnq
al
I
each
I
1 I
9top
1.
mane.
Maximum
vo.
!nq
r.
Amt.
8Pe4d
lstopping
posit
.1
I
each
lonl I
I
I Ou!ck Revocsal f... Marlm”m A. Lern
Maximum
Ahead
O.lck R.ver8al Maxlm”m Ahead
Maxim”.
Aate.
Ma. O1h.
lm. m Ah., r
d
Ma”e”v.,
f,..
to s
n
1.
Stop (as
I
to
i soaclfl.
dl
.“,, s , ,.”,.. 1,
e. 3. 4. S.
6.
Po.lt l.”. ordered may be 1. ie. m. .< RPM .ath. r than Lel. qraph posltlo”. Rep. rt .nq act”ati. n o< .1., ”. and safetg d.v ice., R.o. rt . . . burner f!om.. ut. and . . ..11. <..1... comb. et ion control p-erformanca. Rmport axe. ralona in plant condlt lone e“ch aa bollar water Iev, l, stream P.*saure. sleam dump lnq. .1. . 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 pitch P.. P* II... The destqn of this form end the data c.ll. ctl. n sqatem should b. Lail... d 1. p.ovld. m.anlngt. l Lnto. mail. n baaed on th. P.rf. the
rmenc. Lyp, of
FIG. Q
SP. ciflcat P, OPUI.1O.
ions .q,l.
Centralized
for m
th. ln,l.
Control
90
tqp. tl, d.
of
System
control
Tests
.q.
t.m
and
Dat.
w,, ,,
T.mp,.
1,,.1
0,.(1
(F.
8.1..
D..,
1,1.1
0,,(<
[Afll
1.,.1
dl
S1ANDARD1ZA11ON 6,,, d P., .,
~u”
A;~pa
I
~,v;
:::;
at... ttq
RE5u LTS
o”,
,s::.4
“:!::’
Rpu
K..,,
I 1
2 h“ g 1
11
e A. q 1
COND[11ONS . .
TRIAL
.. .. .. .. ..
Ti., .1 1.*L
R..
P., nt
V!nd . . . ,“,
H*ad1n9
.
-..
[E.,, 1
1
‘
1
Ill 1
NOIES:
.,..
d
!qht
01.
[E,,,.
Et,
CUrr.
v,!.
,
t.dsi
nt
V. L,. O.pth
DIP.
[F...
~@bl*.
I
I
I
I
I
I
1
1
1
!
,
I
,
I
I
I
I
I
I
I
I
I I
I I
I
I
I
I I
I I
I
111
.t,
I
I
!w,”., . )M. ,
1
I
~
I
I
1. R.co.6 e,
.p..
I
I
4ai. f.. .ddlt,. n.l d Pelni h.” aoplloab
:::::
/~.;::.:
TYP.
.f
3. r..9*
n:n69**d/RPM _F1/n.. u*. d
FIG. ~
I
I
.v..6 l*. .“r”**
I
PO1”l. *ho” ti.,
a.
Id 8. app. nd. d t. 1 .11. .
Standardization
91
.ddltio”al
Trials
i
run. Lhla
●t
. fig..,
ql..
” .
Ship Nom.
1,;.! Dtia
fire.
-blent
d,
Relative
H.mitily
of Teat
Duration of T=(
1.mP.
~ Sholt Hwsep.w.r
A..,w
(SHP)
fuel Consumptrnn M,.sur,d SP={NC
Flo. O(G.l. /Hr.) C,.vity
0 60°
Fuel %1 Tempr.ture Specific r..)
Fb
at Meter
C,ovity at Meter
0,1 D.”sity
(w.uNV.flOL,)
Fuel Cons.mptim
(w, UNIT. /Hr.)
Fuel Rate (W. UN~./SHP-Hr. fuel
Rat.
tigher
Corr=tion H.tii~
at M.1.,
for Fwl
) U.d’
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
92
Plant Economy
Test
I
5,,[0
“..,;;.
“-”-” ‘–’—––
‘“-””--–T ;,;:;”;-—––——””
““–”–”‘-–””–”
firlamp.
T;me 0, ,.,,
mb;.nt
Our*ion
R. Lativ. ..midlty
.1 1..1
“–
~ Avwoge Shofi H. MPOWO, (SHP)
I
Fuel consumption
‘“’’’’’’””’’”’”’”’ Fud 0!1 D.n*ily F“.I
(w. UNIT.flOL)
cm..mpfi..
FU.I Rat.
F.* I Rot. High.r
(w.uNI1 ./H,.)
(n.uNfl./sHp-H,.)
br,.clrn” H.oflng
Cov..tio.
for r..l
V.1”.-HW
FU.I R.t.
Fuel Rob
C.m,Ction,
&P. fl.ms
tr.m
c
(W.uN17/sHp-Hr.
)
1.,
mm.
D.s19n Co”dftlonsc
T,* I
Desig.
rtif.
Fa.lor
Correctbn
tic Tempwatur. ( ‘F)
mbrnnt #r Pr.-.re %dt
u-d
b (B~.W.UNn)
Factor 1.7 Hem Available
c.rr.ct.d
hbl.nt
.1 M.t.r
sped
t,HG)
(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
23
Plant Economy
Test
] O“roti.” .1 Test
u.. c.red Specific
I
FI..
0 600
Fb
at Mete,
Specific
Cr.vity
at Met.,
Fuel al
O.n,tiy
(m.uNr,fiOL.
F“.1 consumption
) mt M,ter
(M.uNIT. /Hr.)
~“el Rote (M,uNT,/SHP-H,. R.(9
Corrmlio.
Higher or L..er (8Tu,w.uNm) tirrectbn
F=f.c
Swd
T“tiin.
(
HW b or w
b
Avoiloble
I
‘r)
(-HC)
(RPM)
(RW)
@mPmsr
(RPM)
&wrtio,
bd
ti.tilh.g
Pknt
sip
value
for Hwt
Al, Pr..sure
Sbft
e
)
for Fuel U,.d c H.otlng
hti.ntS, r.m~u,. hbi.”t
S.tic.
(KW) hd
(WO)
Strom
I 101.1
I
H.miditv
o (GOI./Hr, )
Cravily
ruel 0,1 l.m~roluro
fuel
Relative
I
I
I
I
C.mation
FIG. ~
Gas Turbine
I
I
Plant Economy
94
I
I
Test
Ship
Name
Time
of
I
Date
I
Test
Duration
Trial
of
I
Test
Test
Design
Deviation
P~ Average Shaft Steam/Condensate
Horsepower Flow
ISHPI /
(Lbs. /Hr, l
Flowa
Moa8u
red
Flow
Adj”stmentsb
/’
‘\ Adj”stnd
Flow
ILbs ./Hr .)
(Lbs. /Hr.)
Pres6”re
Correction
1. 1.1 Steam
Temperature
Temperature
Correction
1°Fl
Exhdus L Preesure
lHg A)
Exhaust
Correct Ion
Pressure
Shaft
Speed
Spead
Correction
Total
Correction
Corrected
[RPM)
Steam
Factor Rate
a.
[f condensate condensate
b.
Flow adjustments qland leakage
NOTE:
~\\
,/>
Flo. Rate (Lbs. /SHP-Hr. ) Plant Condltlon Corrections Inlet Steam Pres8ure IPSIGI
Make
(L bs,
/S HP-Hr.1
GPM 1s measured, temperature should
8eparate
FIG. ~
meter corroctlon be considered.
Include allowance fOr and alr ejmctor drain.
evaluation
Main Propulsion
sheet
for
Turbine
95
Valva
test
Stem
should
stem
at
Plant
be
leakage.
each
Test
applied
and
turbine
specif!ed
power.
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 if icat ion described below for economy trials, ahead endurance trials, and astern endurance trials, in addition to that called for elsewhere. In cases where Average values for the trial period should be reported. 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 Yet, data for basic design parmeters are necessary to must be provided. 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.
items
It is helpful as follows:
in providing
an appropriate
data plan to categorize
data
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 through 105.
10 Data Sheets which
FIG. ~
Propulsion
96
are provided
Plant Data
on pages
96
Ship Nme Trial
Date
Trial:
Economy,
Shaft
Horsepower
Shaft
Speed
Ahead
Time and Duration
Endurance,
Astern
Endurance,
Boiler
Overload
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
ClaBs ClasB
B A
Class
B
ClaBB
A
Promr
Drum Pressure P/s Superheater Outlet Pressure P/s Superheater tit let Temperature P/ Sa Reheater Inlet PreBsure P/Sb Reheater titlet Pressure P/Sb Reheater Inlet Temperature P/Sb Reheater titlet Tem~rature P/Sb Desuprheater titlet Pressure P/s Desuprheater ~tlet Temperature P/S COfiuetiOn Pertinent Cotiustion
Control cotiustion
control
data to be reprted
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 97
(Sheet
1)
STEM
TURBINE
PLANT
(continued)
Coti”stion
Windbox Furnace Uptake outlet Uptake Uptake Uptake Uptake Fuel
Class Clase
B B
Class
B
Main
( continued)
Air
Pressure P/S Pressure P/S Preesure P/Sc Pressure P/Sc Temperature P/Sd Percent C02 P/S Percent 02 P/S Percent CO P/S
Oil
F. O. F. O. P. O. F. O. F. O. F. O. F. O. F. O. F O. Nutier F. O. F. O. Stem F. O. F. O. F. O. F. O. Nu~er Burner F. O. F. O. F. O.
Settling Tank Temperature Service Pump in OperatlOn Settling Tank in Use Service Pump Discharg~ PreSSUre Meter Reading (Final) Meter Reading (Initial )d Meter Differences Meter F1OW (GPH)d Meter TemFrature of F. O. Heaters in Operation Temperature to Heaters d Temperature from Heaters Temperature to Heaters Heater Drain Temxrature Temperature at Burners PIS Pres8ure at Burners P/S Pressure from Burners P/Se of Burners in Use P/S Tip Size Viscosityc Specific Gravity as Metered Heat Content Btu/lb.
Stea
Atomization
stem
Pressure
to Burnere
PrOuuleiOn Main Turbines
Class Class
B B
Nutier of Nozzles -n Main Stem Pressure at Throttle Main SteTem~rature at Throttlea H. P. Turbine Cheat Pressure H. P. Turbine Chest Temperature H. P. Turbine 1st Stage Pressure
Fig. ~
Propulsion
Plant Data 98
(Sheet 2 )
STEW
TURBINE
PWT
(continued)
Main Turbines
(continued)
H. P. Turbine 1st Stage Temperature Croesover StePressure Crossover Stem Temperature Exhaust Temperature f Extraction Steo Pressures 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 d L. O. TemXrature from Coolere Coo 1ing Water Tem~rature to COOlerS d Cool ing Water Temperature from Coolere d L. O. Temperatures at Main Turbine and Gear Bearings Turbine Governor Oil PK08SUre Temperature at Thrust and LineShaft Bearings, and Other Main
Condensing,
Condensate
and Feed Svstem
Main Condenser
Class
A ‘
Exhaust Tem~rature 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 99
(Sheet
3)
Shaft
Aux.
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
Plant
d
Generator
Class
B
Generator in 0p2at10n Type (AC or DC) Driving Unit (Stem Turbine, Voltage Current Power Factor Power titput Loadg
Diesel,
etC. )
Turbine Oata available
from Ship’s
Auxil iarv Condensing
and Condensate
Condenser Vacuum Cool ing Water Pre9SuKe tO Cool ing Water Temperature cool ing Water Temperature Condensate Pump Discharge Condensate Temperature to
Fig. X
Instruments
Propulsion
Svstem
d
CDnden8er from COndenBer to Condenser Pressure Auxiliary Air Ejector
Plant Data 100
(Sheet 4 )
STEAW
P~T
TURBINE
(continued)
Auxiliary
Condensing
and Condensate
Svatem d
(continued)
Condensate Temperature from Auxiliary Air Ejector Auxiliary Air Ejector Suction Pressure Condensate Salinity Other
Data
The data for the following other systems as mutually for inclusion in the trial report: also recommended
agreed
upon,
are
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, The following should be recorded during the trial runs. to alternating-current, synchronous motor installations. electric drive will rewire data adjustments
additional data relates specifically Other types of
Prime Mover See appropriate PCOPU
Class
B
Power
1s ion
data
sheets
for turbine,
diesel
or gas turbine
Generator
~tput
Teminal Voltage, Field Excitation Current, Field Excitation RPM Cool ing Air Tm~rature Stator Winding Tem~ratures
Voltage,
Class
B
Prouuls ion Motor Power Input Current Input Voltage, Field Current, Field
Fig. ~
Excitation Excitation
Propulsion
Plant Data 101
(Sheet
5)
plants.
STEM
TURBINE
PLANT
(continued)
ProDu 1s ion MOtOr Class
DIESEL
B
(continued)
RPM Cool ing Air Temperature Stator Winding Temperature PROPULSION Main
B (As pertinent to pwer determintion)
PLANT Enaines
Class
Barometer Engine Room Temperature h Air to Engine Pressure Air to Engine Temperatureh 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
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. )
Main
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 102
(Sheet 6)
DIESEL
PROPULSION
PLANT
Lube Oil
(Continued)
(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
Plant
d
Generator
Class
B
Generator in Opsrat ion TyP (AC or DC) Voltage Current Power Factor Power Wtput Loadg Diesel
Ena~
F. O. Consmpt ion and T~ and Proprt Other Pertinent Data as Applicable Boiler
ies of Fuel Used
Svstems Waste-Heat
Boilers
Nutier in Oprat Feed Preesure Fig. M
ion
Propulsion, Plant Data 103
(sheet
7)
DIESEL
PROPULSION Boiler
PLANT
Systems
(continued)
(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
should
The data for the following other syetems 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
as mutually
agreed
upon,
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
Fig. ~
See Sheet
Propulsion
5
Plant Data 104
(Sheet 8)
GAS
TURBINE
Main
PLANT Propulsion Main
Class
B
Class Class Class
B B B
(Each
Engine)
Enaines
and Compressor Speeds Instrumented Points of Pressure and Temperature in the Gas Strem Water Temperature, Barometer and Humidity Engine Air Inlet Pressure and Temperature 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 Turbine
Reduction
Gear
and Clutch
Clutch Fluid Pressures, Air or Hydraulic Lubricating Oil Supply Pressure and Temperature Lubricating Oil Temperatures frOM Bearings Controllable
Pitch Propellers
Hydraulic Operating Blade Poeition
Pressures
and Temperatures
Fuel Oil F. F. F. F. F. F. F. F.
O. O. O. O. O. O. O. O.
Consumption Pump Discharge Pressure Pressure to Engine Pressure from Engine Temperature at Meter Settler Temperature Temperature to Engine ~ and Proprt ies
Lube Oil L. O. Strainer In and at PreSBureS L. O. Cooler In and tit Tem~raturea Cool ina Wate< Heat Exchanger
Fig. ~
In and Out Tem~ratures
Propulsion
Plant Data 105
(Sheet 9)
o
GAs TURBINE
PLANT
Auxiliarv
(cent in.ed)
Electric
Plantd
Generator Generator in Operation Fre~ency Voltage Current Power Factor Power Output Loadg Driver F. O. Consumption
. Class
B
and Type of Properties
Other
Data
should
The data for the following other systems, be included in the trial report:
of Fuel Used
as mutually
agreed
upon,
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 tem~ratures when applicable.
b
Include reheater data when available. If gas reheater is installed, so indicate.
c
When
d
Include data for each unit or system in opration.
e
When appl ictile
f
Include data extract ion
9
Include auxiliary machinery and hotel loads when separable.
h
To engine intake, scavenging or su~rcharging blowers, as applicable.
available.
Fig.
~
Propulsion
Plant Data 106
(Sheet
10)
for each
APPENDIX
CONCTING
A. 1
A TO C~PTER
TURNING
CIRCLE
Using the SPVT, determine ship’s position at suitable time intervals (say 30 seconds) .
A.2.4
A. 3
Plot the ship’s time (SPVT) .
position
at
the
on
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 steady rate 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.
TMCK
A.2. 1 Plot the change of ship’s heading versus time (S~) . A.2.2 versus
ship’s
intervals,
A. 2.5 Fair a dashed line through the plotted points. This will represent the overground track of the ship during the maneuver.
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, tracks will 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 is given. OWRGRO~
Plot
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. selected
A. 1.2
PLOTTING
PLOTS FOR DRIFT
A.2.3
PRINCIPLE
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 .2
6.0
A. 3.2 Detemine from S~ the time for heading changes at 10 degree intervals for the prtion of the
psition
107
for a 360 degrees turn to obtain mean rate of drift expressed in inches of plot per second from “Execute,,.
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. 5
DETEWINATION
CORRECTED
A. 5.1 Using the time plots, determine the time to or from ‘v Execute,, for each plotted point plot. the overground
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 If there are insufficient steady. points to describe the tracks properly, plot more points using the The mean length of SHVT and SPVT. these connections will be proportional to the distance the ship drifted during a full turn; the proportionality factor will be the The mean scale of the plot. direction of the connections taken from first toward the second time the eme heading is reached will be the direction of drift relative to Indicate drift base course. direction by an arrow as shown on Figure 27. Drift direction in compass terms can be obtained by adding or subtracting base course ae appropriate. Report on Figure 6. A. 4
PLOTTING THE DRIFT TURNING CIRCLE
A. 5.2
Multiply
the
times
the
of
from
for each plotted point by the drift rate. This will be the drift distance in inches of plot. “Execute”
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 in direction 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.
OF DRIFT ~TE
A. 4.1 Determine the the from “execute” for each of the connected pints, u:ing the SHVT.
A.5.6 Draw this enter.
a
best-fit
circle
around
A. 5.7 Fair a line through the remaining pints, including a few prior to “Execute”, to redefine the base course.
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. 6
A.4.4 Divide the mean drift distance as plotted by the mean the
DETEWINATION DI~NSIONS
OF TU~ING
CIRCLE
A. 6.1 Scale off the corrected plot and multiply by the scale factor the dimensions defined in paragraph 7.3, DEFINITIONS .
108
A. 7
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.
CALCULATION XNOTS
OF DRIFT
RATE
IN
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.
A. 6.3 Replot the corrected circle; aPP1OPKiately label and indicate the turning dimensions as illustrated in Figure 6 and include this in the trial report. Exmple:
Drift Rate in Knots
= Drift rate (inches lsec) X scale factor (feet or vards/inchi Dimensional constant (feet or yards/nautical mile) (hourlsecs)
109
.
h 5+”
;\
3“’-s’’’”=’ ‘-~~:?:;;y
:
170
----~
,,G
0.79 —/
---
HwDINCS
Sin .-
633
SEC
*“G TIME rOR 360. C. ANCE- +06 scc
,,
!.
.
,W,,,,,,,,,,,,fis AS PLO~ED-0.79,N
,..
.
HOG
7.0
. .
DEFINITIONS
Classification Society - an organization which publishes standards of construction for various 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 of Shipping, Lloyds Register of Shipping, Det Norske Veritas.
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 SNpublications, but they do not conflict. Definitions are set forth as they apply to sections of the guide. 7.1
GENERAL
“If Elected” - a term used guide to designate a trial which will be accomplished explicitly rewired by the or specifications.
in this or test only if contract
TEWS Uncertainty - the probability that measurement of a ship’ s performance par=eter will not be within a prescribed range.
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.
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.
Acceptance Authority - the organizations designated by the Owner Or COntraCt tO rule on the acceptability of trial ~rfomance.
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.
. Reaulatorv Bodies - the organizations designated by the owner or by law to enforce regulations 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.
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.
Prime Mover - the propulsion plant element that converts the thermal energy of the Steor the chemical energy of fuel into rotary mechanical energy.
Ballast Draft - the maximum drafts obtainable without use of dry cargo spaces, using the ship’s ballast sy5tem as installed.
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 it ime 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.
Trial Drafts - the drafts during the See trial under consideration. 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 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.
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.
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.
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.
wer - the net power Shaft Horsem 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 usually negligible.
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 propulsion boilers intended to demonstrate the ability to perfom at a s~cified overload stem output condition.
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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.
.
.
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.
Maximum Desian Shaft Horsepower the maximum shaft horsepower for which the ship is designed to operate continuously. .Classification the
shaft
the
register
Shaft
horsepower of
classification of
mbiguity
-
appearing the
Society. in
Horsepower
the
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.
in
cognizant In
the
case
manufacturers’
the classification shaft horsepower should be considered the maximum design shaft horsepower.
designation,
7.3
mEWRING
Turninq
Trial Shaft Horsepowers - these are distinguished by the method by which they are obtained as follows:
Circle
AND SPECIAL Terms
Base Course - ship heading start of a maneuver. Advance - the distance moves in the direction course.
Torsiometer Installed horsepower being transmitted by the shaft at the point of torpe measurement.
TESTS
at the
the ship of the base
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.
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.
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°.
, 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.
NOTE :
This dtiension is understood if “advance” ie used alone.
Advance of Anv Part of the U - the maximum distance the ship moves in the direction of the base course after the helm order is given.
HUimum
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Transfer - the perpendicular distance from projected base course to the mid length of the ship when the ship, s heading has changed 90”.
distance aft. The total movement of the 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.
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 the
maximum
from any
DeDarture
the part
turning
From Base Track
perpendicular
projected of
the
-
distance
base ship
Ahead Reach - the distance the ship moves ahead after an astern signal is given, comonly determined during trials for a full ahead initial condition and a full astern signal.
course
during
of
7.4
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. “Z” maneuver ie discussed in paragraph 3.8.
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 such the ship’ s track. positions traces The ship’ s psition is calculated using the two ranges, the distance between the surveyed pints, and the position of the surveyed pints.
Final Dimeter - the diaeter of the track made by the ship after the rate-of-change of heading becomes constant.
The
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.
_ - 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
. . &
the
circle.
Z-Maneuver
s
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.
Reversals
7.5
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
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.
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.. :,
Jackina Zero - the no-torqe torsionmeter reading determined by rotating the shaft in each direction with the turning gear and taking the mean of the average readings from both ahead and astern.
-, .
,. .
Water Leq - the correction to pressure gage readings necessary to determine pressure at the sensing point when it is not at the same elevation as the pressure gage and the sensing line is known to contain li~id.
Torsionmeter Constant - the constant used in reducing torsiometer signals to shaft torwe. It is obtained by calculation using the known shaft dimensions, the characteristics of the torsiometer, and a standard modulus of rigidity of the shaft material; or by calibration of the torsiometer while mounted on the shaft.
Red Hand Settinq - position of an adjustable fixed marker on an instrument dial face, which prescribes the high and/or low limits of safe operation.
... ,:
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