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(S L-7-28)
SL-7 RESEARCH PROGRAM
SUMMARY, CONCLUSIONS
AND RECOMMENDATIONS
This document has been approved
for public release and sale; its
distribution is unlimited.
SHIP STRUCTURE COMMITTEE
The SHIP STRUCTURE COMMITTEE is constituted to prosecute a research program to improve the hull structures of ships and other marine structures by an extension of knowledge pertaining to design, materials and methods of
construction.
RAdin Clyde T. Lusk, Jr. (Chairman)
Chief, Office of Merchant Marine
Safety
U. S. Coast Guard Headquarters
Mr. P. M. Palermo Executive Director Ship Design & Integration
Directorate
Naval Sea Systems Coiand Mr. W. N. Hannan
Vice President
American Bureau of Shipping
Capt. R. L. Brown Cdr. J. C. Card Mr. R. E. Williams Cdr. J. A. Sanial
LCdr D. B. Anderson, Secy. NAVAL SEA SYSTEMS COMMAND
Mr. R. Chiu
Mr. J. B. O'Brien
Mr. . C. Sandberg
Lcdr D. W. Whiddon
Mr. T. Nomura (Contracts Adinin.)
MARITIME ADMINISTRATION Mr. N. O. Hammer
Dr. 7. M. Maclean Mr. F. Seibold
Mr. M. Touma
NATIONAL ACADEMY OF SCIENCES SHIP RESEARCH COMMITTEE
Mr. A. Dudley Haff - Liaison Mr. R. W. Rumke - Liaison
SOCIETY OF NAVAL ARCHITECTS & MARINE ENGINEERS
Mr. A. B. Stavovy - Liaison WELDING RESEARCH COUNCIL
Mr. K. H. Koopinan - Liaison
SHIP STRUCTURE COMMITTEE
Mr. J. Gross
Deputy Assistant Administrator for Commercial Development
Maritime Administration
Mr. J. B. Gregory
Chief,. Research & Development Staff
of Planning & Assessment U.S. Geological Survey
Mr. Thomas W. Allen Chief Engineering Officer Military Sealift Connand LCdr D. B. Anderson, U.S. Coast Guard (Secretary)
SHIP STRUCTURE SUBCOMMITTEE
The SHIP STRUCTURE SUBCOMMITTEE acts for the Ship Structure Committee on technical matters by providing technical coordination for the determination of goals and objectives of the program, and by evaluating and interpreting the results in terms of structural design, construction and
operation.
U. S. COAST GUARD MILTARY SEALIFT COMMAND Mr. Albert Attermeyer Mr. T. W. Chapman Mr. A. B. Stavovy Mr. D. Stein
AMERICAN BUREAU OF SHIPPING
Dr. D. Liu
Mr. I. L. Sterfl
U. S. GEOLOGICAL SURVEY Mr. R. Giangerelli Mr. Charles Smith
INTERNATIONAL SHIP STRUCTURES CONGRESS Mr. S. G. Stiansen - Liason
AMERICAN IRON & STEEL INSTITUTE Mr. R. H. Sterne - Liason
STATE UNIV. OF NEW YORK MARITIME COLLEGE Dr. W. R. Porter - Liaison
U. S. COAST GLARD ACADE1Y LCdr R. G. Vorthman - Liaison
U. S. NAVAL ACADEMY
Dr. R. Battacharvya - Liaison
L'. S. ?4ERCHANT MARINE ACADEMY Dr. Chin-Bea Kin - Liaison
Member Agencies: United States Coast Guard Naval Sea Systems Command Military Sea/itt Command
Maritime Administration
United States Geological Survey American Bureau of iipping
Address Correspondence to:
Secretary, Ship Structure Committee U.S. Coast Guard Headquarters,(G-M/TP 13)
Ship
Washington, D.C. 20593Structure
Committee
An Interagency Advisory Committee
Dedicated to Improving the Structure of Ships SR-i 279
1981
This report is one of a group of Ship Structure Comittee Reports which describe the SL-7 Instrumentation Program. This
program, a jointly funded undertaking of Sea-Land Service, Inc., the American Bureau of Shipping and the Ship Structure Comittee, represents an excellent example of cooperation between private industry, regulatory authority and government. The goal of the program is to advance under-standing of the performance of ships' hull structures and the effective-ness of the analytical and experimental methods used in their design. While the experiments and analyses of the program are keyed to the SL-7 Containership and a considerable body of the data developed relates specifically to that ship, the conclusions of the program will be com-pletely general, and thus applicable to any surface ship structure.
The program includes measurement of hull stresses, accelerations and environmental and operating data on the S.S. Sea-Land McLean,
development and installation of a microwave radar wavemeter for meas-uring the seaway encountered by the vessel, a wave tank model study and a theoretical hydrodynamic analysis which relate to the wave in-duced loads, a structural model study and a finite element structural analysis which relate to the structural reponse, and installation of long-term stress recorders on each of the eight vessels of the class.
In addition, work is underway to develop the initial correlations of the results of the several program elements.
Results of each of the program elements are being made available through the National Technical Information Service, each identified by an SL-7 number and an AD- number. A list of all SL-7 reports available
to date is included in the back of this report.
This report documents a review of the SL-7 research program with a suninary of each aspect and outside ancillary projects; presents a set of conclusions, and makes recoirnendations for further analysis
of some data.
T.chnicc R.port Docvm.rtation Pag,
F.rr DOT F 1700.7
(I-72)si c.isI.t.d p.s. ..ìith.rlud
ii i
Bibliotheek van cie
Afdeing Scheepsbouw- en Scheepvaartkunde
Techrsche Hoaeschoo, DeIt
DOCUMENTATIE
I: '- I3
DATUMI
L ND.
SSC-313 (SL-7-28)
2 G...'..'' Acc.&i.en Pio. 3 R.c,p,n' s Csg No.
1. .« S.ibt,I.
SL-7 Research Program Sutmixary, Conclusions and
Recomrnendat ions 5. R.po Dot. August 1981 6. P.tf0,,, C.d. 8. P.rf0 Otgoni.to R.por? N0. SR-1279 7. A.jti,o"&) . .
Karl A. Stambaugh and William A. Wood 9. P.tfetmng Orgoaret' Nom. w Aàch.iii
Giannotti & Associates, Inc. 703 Ciddings Avenue, Suite U-3 Annapolis, Maryland 21401
10. Worh Urtt No. (TRAIS)
n. Cont,octotGton'No.
DTCG2380C20025
13. lyp. of R.pott nd P.,od Co.r.d
Technical Report 8 14 80 - 8 10 81
12. $ço.orn Ae.tcy No".. .d Adth.io
U.S. Coast Guard
Office of Merchant Marine Safety
Washington, D.C.
20593 eor.sotno A.ncy C.d.G- M 1$. $,ppI.,,.,ntry Notti
Contract monitored by: Ship Research Committee National Academy of Sciences Washington, D.C.
16. Ms..cl from its first inception,tbe
stone in maritime history.
design, classification, construction when the opportunity presented
in a research program for the vessels. Like the SL-7 vessels
come a milestone itself.
The report that follows, "SL-7 fions," reflects mainly upon tains an evaluation of the
namely, Full-scale Instrumentation, and Hull Girder Load Criteria with emphasis on how the program
The report contains appendices tation and describing the data future data users.
At this time, it appears obvious The massive amounts of full-scale doubtedly be a most valuable for many years to come. The ing of the sea and the ships within the marine industry, within the industry. These
SL-7 The SL-7s advanced and itself for full-scale themselves, Research Program: the technical SL-7 research Model Analysis. results summarizing recorded on that the hull response source of data program has greatly
that sail on it has fostered long-term benefits
containershfp program represented a mile-the state of mile-the art in such areas as ship operations. It was indeed fortunate
the Ship Structure Committee to participate measurement of hull girder stresses on these the full-scale measurement program has
be-Summary, Conclusions and Recoinmenda-content of the program. This report con-program according to four main elements,
Testing Techniques, Analytical Techniques Conclusions are derived from the evaluation may benefit future programs of similar nature.
the relevant SL-7 research program documen-the S.S. SEA-LAND McLEAN that should aid
SL-7 program has been a tremendous success. data that have been recorded will un-for researchers, designers and students
increased our
knowledgeandunderstand-it. As a program involving many disciplines
a spirit of cooperation and communication represent the real success of the SI-7
15. Dsttibvoa S.e.'..,' research program.
17. K.y Wø
Ship Research Ship Structures Structural Analysis
Ship Response and Instrumentation
19. $.cur.ty C(..sf. (.4 $,s ,so1) . S.cu'uty C4..sf. (.1 thi p.s.) 21. N.. I P.ç.i
138
METRIC CONVERSION FACTORS
Approximate Conversions to Metric Measures
ta
Approrimale Conversions from Mefric Measures
=
es Symbol Wh.s You know Multiply by To Find Sy.bsl Symbol Wh. You kuew Multiply by T. Fied Sy.lbsl -LENGTH inches inches in feet lt yards ymi eitles rei AREA fl2 square incIses 6.5 squrare ceertimetars coi2 ..__E ti2 square test 0.09 square meters m2 yd2 square yards 0.8 square meters m2-=
eri7 square miles 2.6 square hrtretsete,s km2 ..._. -0.4 hectares lia cm2 bei2 ha MASS (weight)-E
:
MASS (weight) on ounces 28 8 __:=
g grams 0.035 ounces ox lb pounds 0.45 kilograms kg- =
-kg kilograms 2.2 pounds Ib shunt torts 0.9 -t tonnes 1000 kg) 1.1 sheet tiers (2000 lb) -VOLUME VOLUME tsp teaspoons 6 milliliters nil ml milliliters 0.03 fluid oouces Il ox lbsp tablespoons 15 milliliters ml I liters 2.1 pints pl Il on llaul ounCes 30 milliliters ml i.t ._.. I liters 1.06 quartS qt cups 0.24 liters I n-I liters 0.26 gallons gut pi pints 0.47 titers I-:
et3 cubic meters 35 cubic feet Il ql quarts 0.95 liters I -ni3 Cubic meters 1.3 cubiC yards yd3 gal gatloos 3.8 liters I ti3 cubic lent 0.03 cubic meters iii3 yd3 cubiC yards 0.16 cubic teeters m3 ta -'t TEMPERATURE (exact) TEMPERATURE (exact) -E u -c Celsius 9/5 (then Fahrenheit F treriperatare add 32) temperature Fahrenheit 5/9 latter Celsius uC temperature subtracting tenipeiatoie 32) ...: uy 32 98.6 2i2 -40 0 40 80 j 120 160 200 .55 .otiyi.I mum. mier et.i.. iio,mrieis omis
muon deiuiiriut iobhes.
eu Nus kisc. Posi. 206.
3
:
-Ij
imiti? t
t i f t i t i L uJ,ioi Wrimyimic Oint Mrasorrs. Pimcn $2.25. SO Cataloij No. C13.iy:706.
40 20 0 20 140 60 80 lOO
- =
nc 37 C millinintets 0.04 centimeters 0.4 meters 3.3 meters i .1 kilmmeters 0.6 LENGTH inri -cm -in inches 2.5 centimeters Citi -m ti tent 30 centimeters cm -m yards 0.9 meters m hrn mr miles 1.6 kilcuselers km n-AREAsquare cent meters
0.16 square inches in2 square meters 1.2 square yards square kilcaneters 0.4 square miles ml2 hectunes 110.000 ni2) 2.5 acres
CONTENTS
Page
1.0 INTRODUCTION i
2.0 BACKGROUND 1
2.1 INFLUENCE OF PRIOR WORK LEADING TO THE SL-7 RESEARCH
PROGRAM 2
2.2 DESIGN OF THE SL-7 CONTAINERSHIP 2
3.0 REVIEW AND SUMMARY OF THE SL-7 RESEARCH PROGRAM 3
4.0 EVALUATION OF THE SL-7 RESEARCH PROGRAM 11
4.1 EVALUATION OF INDIVIDUAL SL-7 PROJECTS li
4.2 SUMMARY OF THE SL-7 RESEARCH PROGRAM EVALUATION 11
4.2.1 Full-Scaie Instrumentation 11
4.2.2 Model Testing Techniques 55
4.2.3 Analytical Prediction Techniques 55
4.2.4 Load Criteria, Analysis and Development 56
4.3 OVERALL EVALUATION OF THE SL-7 RESEARCH PROGRAM 57
5.0 RECOMMENDATIONS 59
6.0 EPILOGUE, ThE SL-7 CONTAINERSHIP 61
7.0 ACKNOWLEDGEMENTS 61
8.0 REFERENCES 62
APPENDIX A - SUMMARIES OF REFERENCES i - 34 A- i
APPENDIX B - SL-7 RESEARCH PROGRAM DATA BASE DESCRIPTION B- 1
Figure 2-1 Figure 2-2 Figure 3 1 Figure 4-1 Figure 4-2 Figure 4-3 Figure 4-4 Figure 4-5 Figure 4-6 Figure 4-7 Figure 4-8 Figure 4-9 Figure 4-10 Figure 4-11 Figure 4-12 Figure 4-13 Figure 4-14 Figure 4-15 Figure 4-16 Figure 4-17 Figure 4-18 LIST 0F FIGURES Page
Midship Section of the SL-7 Class Containership 4
SL-7 Body Plan, Stem and Stern Outlines and Curve of
Sectional Areas 5
Representation of an Open-Decked Ship 8
SL-7 Data Comparison 14
Hatch Deflection Measurements from the Calibration
Experi-ment Performed on the SL-7 SEA-LAND McLEAN 16
Comparison of 4 RNS Estimates from the OWHS Radar with
Cor-rected 4 RNS Estimates from the Tucker Meter All Intervals 20 Comparisons of 4 RMS Estimates from the OWHS Radar with
Cor-rected 4 RNS Estimates from the Tucker Meter: Intervals Plotted are Restricted to Those for Which the Radar Spec-trum Area above the Low-Frequency Integration Cutoff is
Greater than 80% of Total 20
Histograms of Scratch-Gauge Data Measured on the SL-7
Resource 23
Miscellaneous Details of Scratch Records 24
Illustration of Scratch-Mark Equivalent to Complex Time
History of Stress 25
Comparison of SL-7 Stresses at Frame 178 During Positive
Torsion 29
Representative Loading Applied to the Steel Structural Model 30
Hatch Distortion vs. Stresses in Transverse Box at Fr. 178, Port Side-Section B due to Torsional and Lateral Moments for
the SL-7 Containership 32
Stress Distribution due to Wave-Induced Vertical Bending
Fr. 142-146 Second Loading Case 33
Stress Distribution due to Lateral Bending and Torsional
Moments Fr. 142-146 Second Loading Case 33
Midship Vertical Wave Bending Moments and Wave Phase Lag,
1800 Heading 35
Midship Vertical Wave Bending Moments and Wave Phase Lag,
0° Heading 36
Midship Torsional Wave Bending Moments and Wave Phase Lag,
30° Heading 37
Midship Torsional Wave Bending Moments and Wave Phase Lag,
240° Heading 38
Midship Vertical Wave Bending Moments and Phase Lag, 180°
Heading 41
Midship Vertical Wave Bending Moments and Phase Lag, 00
Heading 42
Figure 4-19 Figure 4-20 Figure 4-21 Figure 4-22 Figure 4-23 Figure 4-24 Figure 4-25
LIST OF FIGURES (cont'd)
Page
Midship Vertical Wave Bending Moments and Phase Lag,
30° Heading 43
Midship Torsional Wave Bending Moments and Phase Lag,
2400 Heading 44
Comparisons of Structural Model Tests and Finite-Element
Calculations for the SL-7 Containership, Loading Case 1 46 Comparisons of Structural Model Tests and Finite-Element
Calculations for the SL-7 Containership, Loading Case 2 47 Comparisons of the Wave Time History Measured on the
SEA-LAND McLEAN and the Regular Wave Representations (Condition 15 Voyage 32w Tape 145 Index 18
-Interval 5 - Run 405) 51
Comparisons of the Wave Time History Measured on the SEA-LAND McLEAN and the Regular Wave Representations (Condition 16 Voyage 32W Tape 145 Index 29
-Interval 50 - Run 450) 51
Comparison of the Calculated and Measured Midship Vertical Bending Stresses (Sensor LVB), Wave
Condition 15 52
Figure 4-26 Comparison of the Calculated and Measured Midship Vertical Bending Stresses (Sensor LVB), Wave
Condition 16 52
LIST OF TABLES
TABLE 2-1 CHARACTERISTICS OF S.S. SEA-LAND McLEAN
TABLE 3-1 SUNNARY OF SL-7 RESEARCH PROJECT USING THE SL-7 DATA OR AS REPRESENTATIVE HULL TYPE
TABLE 4-1 EVALUATION OF THE SL-7 RESEARCH PROGRAM 12
Page
6
1.0 INTRODUCTION
The SL-7 is an eight-ship class of high-speed containerships conceived owned and operated by Sea-Land Services, Inc. (Sea-Land) in both North Atlantic and Pacific trade routes. A research program involving these
ships was initiated by Sea-Land, the American Bureau of Shipping (ABS) and the Ship Structure Committee (SSC), with additional projects funded by the United States Coast Guard and the United States Navy. The pro-gram represents an excellent example of cooperation among private in-dustry, classification societies and government. The goal of the pro-gram was to advance the understanding of ship structural performance and
the effectiveness of analytical and experimental methods used in design. A long-range goal of the program was to obtain information for reaching
the SSC's goal for the development of rationally-based system load cri-terion for the design and analysis of shIp hull structures. While the full-scale measurements, model experiments, and analyses performed as part of this program were keyed to the SL-7 class containerships, many of the conclusions of the program can be generalized and applied to other surface ships. This report includes a summary of the overall program, outlines some of the details of the program planning, describes the cor-relation, comparison and validation efforts, and finally, addresses re-commendations for further analysis of the SL-7 program data base.
This report is organized into four basic sections. The first section presents the background leading up to the initiation of the SL-7 research program. The second part presents a review and summary of the SL-7 re-search program and describes the program elements and general goals of SSC that form the common thread for the program. The second section is intended to provide the reader with some insight as to the relationships between the various program elements. The third part of the report
con-tains an evaluation of the research program documented in References l-34, relative to the program goals and objectives, and an overall summary of
the conclusions is presented based on the evaluation of the research pro-gram. The fourth and final part of the report presents the
recommenda-tions which may be derived from the SL-7 research program.
Two Appendices are included which provide background information pertinent to the evaluation, conclusions and recommendations. Appendix A contains individual summaries of References 1 through 34, and Appendix B contains a description of the full-scale data base of ship response information recorded on the S.S. SEA-LAND McLEAN.
2.0 BACKGROUND
The SL-7 research program has deep roots in the research history of the SSC. This program was preceded by other programs which included exten-sive model tests, computer analyses and full-scale data collection and analysis. In fact, most of the full-scale vessel instrumentation tech-nology in use today was developed under the sponsorship of the SSC. In planning for the SL-7 Research Program Summary, Conclusions and Recommen-dations, it was necessary to review the reports of the preceding related programs in order to provide a basis from which the SL-7 research program
has evolved. Many of these prior programs have had a profound impact and influence in the formulation of methods for full-scale ship data acquisi.-tion, in stimulating related research in the private sector, and in ad-vancing the state of the art for ship design.
2.1 INFLUENCE OF PRIOR WORK LEADING TO THE SL-7 RESEARCH
PROGRAM
The background research that preceded the SL-7 research program is dis-cussed in detail by Siekierka, et al in SSC-257 (5). It is from this background that the SL-7 research program has evolved. The following is a synopsis of the influence of these studies on the elements of the SL-7 program:
Previous full-scale instrumentation programs have provided valu-able ship hull load and response data that facilitated the develop-ment and validation of design methods and techniques. However, a quantitative description of the wave environment was lacking. The analytical techniques for predicting ship bending moments due to waves have not been validated directly using full-scale data because of the absence of accurate wave information in previous
full-scale programs. The wave data are essential to further develop load-prediction techniques and to achieve a greater confidence in the results of the predictíons.
The full-scale stress data that have been collected are helpful in examining load design criteria for ships similar to those for which
stress data are available but cannot provide direct guidance in designing different types of ships.
A technique has been developed for extrapolating full-scale ship wave-induced bending moment data and is based on environmental data
encountered by the ship in question. This technique may also be used to synthesize bending moment data by using model test results or computational analysis and provides the designer with a valuable tool in predicting wave-induced bending moments.
The ship structural load criteria presented in SSC-240 (35) needed further validation and development for use with different ship types and varying types of load conditions.
2.2 DESIGN OF THE SL-7 CONTAINERSHIP
The concept of a high-speed containership was conceived by Sea-Land in the late l960s. At the time, fossil fuel was still relatively inexpensive, and it appeared that the high-speed containerships were the way of the future for cargo transport. The design of the SL-7 was begun in early 1969 by Sea-Land, J.J. Henry, and The Netherlands Ship Model Basin (NSMB).
The structural design considerations for the SL-7 class of containerships were presented by Boylston (36) and represented the state of the art at the time in applying design tools and methods. During the initial
investigations, the application of modern design methods was still in its infancy and consequently the analyses commenced at a simple level, building up to more sophistication as the work progressed.
The design bending moments were determined statically on a wave equal to the ship length and of a height equal to 2.2 L°4 = 30 ft. It was deter-mined that the hogging moments were larger than the sagging moments by a
factor of about 4 (36). A dynamic analysis was conducted based on the methods presented by Grim and Schenzie (37). The torsional rigidity of
the containership was also considered in the design stages, where the tor-sional moment was determined using the procedure outlined by deWild (38). Concurrently with the determination of the wave loading, a course mesh finite-element model of the ship was developed. This was one of the early attempts to model a whole ship. The structural analysis showed that deck structure in way of the engine space and transverse bulkheads between each hold limited the torsional-induced warping and deflection of the hull gir-der, thus minimizing the torsional deflections at the hatch corners near
the ship's quarter points. The resulting midship section as constructed is shown in Figure 2-1. The body plan is presented in Figure 2-2. An additional finite-element analysis was conducted with a much finer mesh as part of an extensive vibration analysis.
A series of model studies was conducted at the NSMB (36) with emphasis on hull form development and resistance. Seakeeping tests were also conduc-ted and measurements were obtained for ship motions, accelerations and relative motions at the bow and stern in irregular seas corresponding to a wind force Beaufort 8 in the North Atlantic (significant wave height 16 ft. and average period 8.5 sec.) approaching from ahead, the bow quarter, abeam, and the stern quarter. The relative motion data indi-cate that for this sea state no water would be shipped over the foredeck. However, emergence was not experienced and it was concluded that slamming would be minimal in Beaufort 8 seas.
There were 8 vessels of the SL-7 class constructed at three different European shipyards, which included Rotterdam Dockyard, A.G. Weser, and
The principal characteristics of the lead ship of the SL-7 class, the S.S. SEA-LAND McLEAN (McLEAN), are shown in Table 2-l.
3.0 REVIEW AND SUMMARY 0F THE SL-7 RESEARCH PROGRAM
A three-phase SL-7 research program was proposed by Sea-Land and ABS
before the SSC became involved. Sea-Land was interested in instrumenting the first ship of the class, the McLEAN, in order to validate design de-cisions and procedures, while ABS was interested in conducting
finite-3
Rheinstahl Nordseewerke. The vessels were:
S.S. SEA-LAND McLEAN S. S. SEA-LAND FINANCE
S . S. SEA-LAND GALLOWAY S.S. SEA-LAND MARKET
S.S. SEA-LAND TRADE S.S. SEA-LAND RESOURCE
I,
!IIW
30"n6"s044'° (760 150 11) 60" 0.67/13" 1 00" 1524 16/330 2501 60" 0.75/13 1 25" t 1524 19/330 321V'
0.875' (22) Plato,g 61' 0.875' (155 22) 1.35" (34) KIet -8' 9" (2,667)Mots Eqi.oalanti noee' n
a ron,indSO Ott
Long
062" (161
9' .1/7' (2.7811
Top o) Coamng Parallel to B. L
26'. 6" (8.0771 I 0,71" (18) At ends IALFBEAM 52' ' 9" (16,079)
7
7*
0.82" 121) Eng.n. Room 30' 60' n 0.67/10 1/2 n 062" (1524 n 15/267 n 16) 0.62" (16) 8' 7 1/2" (2.629)i
Second Deck-4
In-Snnger Mo ¶ I Man, Deck Sringer No 2 Strlrtqer No. 3 Tank Top ¶2" (300)Figure 2-1 Mid-Ship Section of the SL-7 Class
Containership S.d. Shell 0.8" 1211 At Ends 0.64" 116) Immersed Bow 0.78" (20) Foci S.d. 0.58" (15) Poop 5.0. 0.51" (13)
Bottom and Bilge 1.375" (35, Bottom Forward 1,30" (33( Lower 8.lg. Strait. To 8e Grade CS or E StasI BL. B,)ge Keel 0.75" PL. (19) 200 n 100 i 22 0.685" 1171 NT. CV(T 0.80" (201 0.72' (18) At Ends 0.62' (16) 8 n 4 t 7/8 L 8 n 6 n 1" L (200 n 150 25) 8' 9" (2.6671 9'. 1/2" (2.781)
Ui
Figure 2-2
SL-7 Body Plan, Stem and Stern Outlines and Curve of
Propeller RPM
Speed, maximum, knots
Center of gravity - full load
Section modulus, FR 186, top: Section modulus, FR 186, bottom:
Neutral axis, FR 186
Fuel oil Capacity (98% full)
Salt water Ballast Capacity
TABLE 2-1
CHARACTERISTICS OF S.S. SEA-LAND McLEAN
Name: SEA-LAND McLEAN
Builder: Rotterdam Dry Dock (Hull 330)
Class: SL-7 Containership
Length, overall
Length, between perpendiculars 880' 6"
Beam, molded 105' 6"
Depth to main deck, aft Q 69' 9"
Depth to main deck, forward Ç 65' 3"
Camber from Q 1' 3"
Draft, design 30' O"
Draft, scantling 33' 0" Dead weight - lone tons 27,315
Displacement (34' 0" draft) - long tons 50,315
Machinery Two separate cross-compound stem turbines driving two propeller shafts (Bunker C oil)
Shaft Horsepower-maximum continuous,
both shafts 120,000
135
33
399.32' forward of aft per-pendicular 42.65' above base line
1,745 x io6 in3
2,166 x io6 in3
342.5 in above base line
5384 LT 9656 LT Container Capacity 8' x 8.5' x 35' 8' x 8.5' x 40' Total Below deck 554 140 694 Above deck 342 60 402 TOTAL 896 200 1,096
element analyses and structural model tests in order to exercise and validate their relatively new finite-element computer program, DAISY. SSC eventually became involved in the project and supplied additional funds and technical guidance through a Project Advisory Committee of the National Academy of Sciences/National Research Council.
Several design-related problems prompted the initiation of the SL-7 re-search program. Each participant, Sea-Land (designing, building and operating), ABS (classification), and SSC (research), had specific in-terest goals to achieve through participation in the program.
The specific design features of interest to Sea-Land were primarily in areas of stress concentration at the hatch corners where the ship trans-forms from a flexible open box to a rigid closed box structure and where the transverse box girders interact with the longitudinal box girders. These locations are represented in Figure 3-l. They were also of
special interest since the diagonal displacements of hatch openings sub-sequently caused large stresses at the girder intersections and problems with the hatch cover seals.
One of the primary goals relative to SSC's objectives for the full-scale portion of the SL-7 research program was stated in Siekierka in SSC-257, Reference 5, "The results of the wave-induced stress measurements (on the McLEAN) will be compared with model and computer analytical data. The ultimate aim is to secure sufficient confidence in the calculation procedure, so that model testing and full-scale data collection may be eliminated," Further applications of full-scale data discussed in the following sections will consider Siekierka's statement as one of the primary objectives of the full-scale instrumentation installed on the SL-7 class of ships.
As stated by Chazal in SSC-252 (39), the overall goal of the SSC for the SL-7 research program was to "either develop or provide supporting evi-dence for rational design methods for ships." Fundamental to any rational design method is the ability to characterize the actual struc-ture using predictive techniques such as mathematical analysis or model testing. With either method, correlation factors must be applied which relate the predicted results to the actual full-scale structure. Deter-mining these correlation factors and refining the predictive techniques are implicit objectives of research into ship structural design methods. Within this framework and the historical background presented, the SL-7 research program was developed with the following four distinct elements:
A full-scale instrumentation project consisting of measurement of hull stresses, rigid-body accelerations and environmental data, and long-term extreme strain recorders.
Use of model-testing techniques for the prediction and validation of ship dynamic and static loads and responses.
Development and validation of analytical tools and techniques for ship motion, load and response characteristics, including finite-element computer programs.
Figure 3-1 Representation of an Open-Decked Ship
8
Strain gauge locat ion
4. Development and analysis of lifetime hull girder load criteria for
ship structural design based on statistical evaluation of full-scale data.
In subsequent sections of this report, each of these elements, their interrelationships and impact on design methods, will be summarized and evaluated with respect to the program's objectives and goals.
The SL-7 research program as initially conceived contained specific in-dividual projects to implement the broad program elements.
A full-scale instrumentation program was proposed to obtain full-scale measurement of seaway loads and response. This included the design and installation of an instrumentation system, the
calibra-tian and operation of this system, and reduction and analysis of selected amounts of data.
A series of hydrodynamic model tests were proposed to investigate wave-induced vertical, horizontal and torsional bending in the hull
girder.
A model test was proposed to measure stresses and deflections of a small-scale structural model under separate and combined torsion and bending.
An analytical analysis was to be conductedwhich included the use of a finite-element program, DAISY, to analyze the structural res-ponse of the SL-7 containership.
A theoretical hydrodynamic analysis was to be performed applying the SCORES computer program for predicting the loads and response of the SL-7 containership in regular waves.
It should be emphasized that prior to completion of the full-scale instru-mentation data reduction and analysis, the other program elements were initiated. The relationships between projects listed above are described in SSC-257 (5), which includes a description of the planning effort in-volved in the validation and verification of load, motion and response predictions. Not all of the recommendations for research presented in
SSC-257 (5) were funded, and several were integrated into one project. As the program evolved, it developed into a more extensive program which included further analysis of data obtained from the initial program and development of additional related projects. These follow-on projects continued the validation and development efforts and full-scale data reduction that had begun in the initial part of the SL-7 research program. Most of the results of the SL-7 related research projects have appeared as SSC reports. Summaries of all SL-7 related project reports and tech-nical papers are presented in Appendix A. Some SL-7 related projects have received separate Coast Guard, Navy, or ABS sponsorship. The
pro-jects which will be evaluated in this report are listed in Table 3-l. A description of the McLEAN data base is presented in Appendix B. This
lo
TABLE 3-1
SUMMARY OF SL-7 RESEARCH PROJECT
USING THE SL-7 DATA OR AS REPRESENTATIVE HULL TYPE
* Based on full scale data obtained from Teledyne Engineering Services ** No document has been published to date.
SL-7 PROGRAM ELEMENTS PROJECT
ORIGIN (location of data) ASSOCIATED REFERENCES Full Scale Instrumentation
Hull response measurement on the
SL-7 SEA-LAND McLEAN Teledyne EngineeringServices 1, 7, 8,
9, lO
Shipboard wave measurement
systems on the SL-7 SEA-LAND McLEAN
Teledyne Engineering
Services
10
Naval Research Lab 13
Stevens Institute of Technology
14_23*
Scratch gauge data on the SL-7
class containerships (including the McLEAN)
Teledyne Engineering
Services 25
Giannotti & Assoc. ,
Inc.
31*
Model Testing
Techniques of the SL-71/140th Scale model tests Stevens Instituteof Technology 2
Steel structural model tests of
the SL-7 University of
California, Berkeley 11
PVC rigid vinyl structural model
tests of the SL-7 David Taylor NavalShip Research &
Development Center 6
Open water model tests of the
SL-7
University of
California, Berkeley 26,27
Hull pressure model tests of the
SL-7 University of
Michigan
**
Analytical Techniques SCORES computer simulations of
the SL-7 Oceanics, Inc. 4, 12
DAISY Finite Element Analysis
of the SL-7 American Bureau ofShipping 3, 24, 30
Time domain computer simulation of capsizing for the SL-7
University of California, Berkeley
26,28,29
Hull Girder Load
Criteria Analysis
Examination of service stress data (includes the SL-7 as a
ship type)
Stevens Institute of Technology and
Rosenblatt & Son, Inc.
33*
Evaluation of full scale wave loads (includes the SL-7 as a
ship type)
HS-1 Panel, SNAME 34*
Fatigue load spectra development
description presents a summary of the data acquisition, data reduction methods, and data formats.
4.0 EVALUATION OF THE SL-7 RESEARCH PROGRAM
This section provides an overall evaluation of the SL-7 research program. Section 4.1 discusses the validity and usefulness of the results derived from each project in the four main program elements described in Table 3-l. Section 4.2 summarizes the evaluation, conclusions and contributions made by each project in the four main program elements. Section 4.3 pre-sents an overall evaluation of the SL-7 research program.
4.1 EVALUATION OF INDIVIDUAL SL-7 PROJECTS
Evaluations of each of the projects listed in Table 3-1 have been cate-gorized accordíng to the four main elements of the SL-7 research program and are summarized in Table 4-l. The contributions of each project in
achieving the SL-7 program goals are summarized with respect to develop-ment of specific structural design methods, motion and load measuredevelop-ment
and prediction techniques, and rational hull girder load criteria. In many cases, the evaluations of individual researchers are presented with additional comments on overall observations, assumptions, limitations and applications of the projects considered. Special attention is given to the lessons learned from the SL-7 research projects that may be of benefit to future data users and those considering other programs of a similar nature.
4.2 SUMMARY OF THE SL-7 RESEARCH PROGRAM EVALUATION
This section presents a summary of the SL-7 research program evaluation which includes the primary observations obtained from the evaluations of
each individual report (References l-34) presented in Section 4.1. As per the individual evaluations, the summary is organized according to the four elements of the SL-7 research program.
4.2.1 Full-Scale Instrumentation
Although the McLEAN data base has several limitations, it still represents a major source of full-scale data for use by the marine coLluuunity in gen-eral. The major limitations of the McLEAN data base have been indicated in the evaluation section and include the lack of an initial mean stress datum prior to departure for each voyage (the gauges were zeroed prior to departure and no record of the initial mean stress was kept), the
made-quacy of motion measurement devices (roll and pitch pendulums), and the unreliability of measured wave data. The latter limitation of the data
base severely limits further applications relative to verification of analytical prediction techniques. The research plan outlined by
Siekierka in Reference 5 was heavily oriented to using the McLEAN data base for validation purposes. The wave-measurement limitation has pre-cluded the achievement of this goal. It is also interesting to note that the research plan did not include hull girder load criteria
analy-sis and development even though the data collection techniques were heavily oriented toward gaining a substantial statistical sample.
ionic a-,
EVALUATION OF THE SL -'T RESEARCH PROGRAM Element :
flut- SCALE INSTRUMENTATION
R.por I
Ill le
SSC No. Ref. No. Pub. DCI.
ContrIbutIon of 1h. Study In Achieving the SL 7 Research Program Goal,
SlrucluraI Design Method. Specific to h. SL- 7and Conlainershlpa in General M.esurement and Prediction of Ship Loed. MotIon and Str...
Rational Hull Girder Load Criteria Analysis and Development Including Slalislical Evaluallon of Dele
Design and Installation of a Ship Nesponse instrumentation System Aboard the SL-? Clans Containershtp S.S.
SFA-I.AN[i
Mci.P.AN SSC-23l1 Reference (I) 1974
e
Many of the instruisent locations were intended n provide design information to Sea-Land directly. Sea-i.asd obtained data to sake assessment of: (a) Hatch covers and coaniinga (b) Deck Cutouts (c) Cell gulden and transverse
hulk head 8tructsre
(d) Container design (e) Internal container cargo
restraint systems
(f) Habitability in forward and
aft houses
(g) fleck and shell loadings in bow
area
(h) Rigid on-deck container
ueciir Ing system
Pin documentation on the data (ir results obtained by Sea-land is avaiiuhie to the generai public at this time,
a
No loads per ne were measured on tire Si.-), only responses.
Measurement
of the wave environment vis attempted using a Tucker wave meter arid a radar wave meter.
The
measurement of wave environment was intended to facilitate comparisons between lull acate and analytical predictions.
See the lolliseing
dis-cuss ion of References (li) - (23) and sumaries in Appendis (A) for an evaluation of the meter systems.
a
The angular notions measured ori the SL-7 were obtained from pendulums. Accelerations of the pendulum pro- duced measurement errnrs.
(See
discussion In Reference (23) for further evaluation.)
e
Strain-gauge locations represented the state rif the art
In
strain-gauge placement with impuls by ARS. SSC advisors and Sea-land.
Ilowever,
there is Minimal diri-uaentation on the rotirinale involved with instrumentation neiectii,n, piace- nient, purpose, uniI data reduction required.
ti
intlierelore difficult
to fully evaluate tIre insrrumenla- t ion system installed in the SlA- i,AND Mi'I,EAN with limited (conit
s
TABLE
EVALUATION OF THE SL - i RESEARCH PROGRAM Étamant :
FULl, SCALR INSTRUHItNTAT ION
Raport
Titi.
SSC No. U
.
S
Contribulfon of h. Study In Achisvingth.SL-7 Ras.arch Program Goal.
Structural Dsalgn M.ttsod. Spsclfic to the SL- land Contatn.r.hip. In Gineta I M.e.ur.m.nt and Pr.diclion o! Ship Load, Motion and Strits Rational Hull Gird., Load Crit.ria Analy.Is and Dan.iopm.nt Including Statiaticul Evaivaiion of Dala
Continuation of Reference (i) SI.-? instrumentation Program Background and Research Plan SSC-257 Reference (S) 1916
A significant feature of the test pian outlined in the report ix that it did not include piana to develop methods for containership design. documentation of specific objectives and requirements for data acquisition and reduction.
Titis
lnforrsation,if available, would be of great benefit for future full- scale instrumentation programs of a similar nature.
For example, the
information could aid In the determination of strain-gauge instrumentation placement without going through the deliberations that must have taken place in deciding the placement of strain gauges on the SEA-LAND MclEAN. The report presenta a research plan, developed by s few individuals and reviewed by the Project Advisory Cou- nittee of SSC. that
in oriented
directly at the validation of anuly- tirai ptediction techniques.
An ,ver.
all chart of the plan ix presented in Figure 4-I.
The overall plait for
validation was very good;
but was
dependent on obtaining an accurate picture of the wave environment actually encountered In order to obtain a salidal ion of analytical prediction techniques.
a
HYDRO MO D EL T ES IS (STEVENS INSTITUTE) MOTiONS & LOADS ANALYS IS (OCEAN (CS) SHIPBOARD MEASUREMENTS (TELEDYNE) (SEA WAYIIMOTCONSI ISTRESSI
'ç
V
/
LOAZi.r
-14 STRUCTURAL ANALYS IS CABS) Transfer of ResultsComparisons of Project Results
Optional Comparisons of Project Results
TABLE 4-t (cont'4),
EVALUATION OF THE SL -7 RESEARCH PROGRAM El.m.nt
F'IJLL SCALE INSTRUMENTATION
R.porl
Till.
SSC No. Rd Nø U
Contribulion of 1h. Study in A.chlaving th.SL- 7 R.ssa,ch Program Goals
Structural Dasign M.thods Spscllic Io h. SI-7 and Conlaln.rshlps in G.naral Ueasur.m.nt and Prediction of Ship Load. Notion and Str...
Rational Hull Gtrd.r Load Criteria Analysis and D.v.lopmsnl including Statistical Evaluation of Data
Static Structural Calibr.tion of Ship Response Instrumenta- Lion Syste. Aboard the SEA-LAND I40LEAH SSC-263 Reference (I) 1916 First Season Results from Ship Response Instrumentation Aboard the St-I Class Containership S.S. SM-LAND licitAN in North Atlantic ServIce SSC-264 Reference (8) i9?6
s
During the calibration experiment, hatch deílecttonn vere measured as a resait of a known loading to infer a relationship between batti, deflection and measured stresses.
This
informa-lion wan useful in Inferring a hatch displacement [ro. seaway-induced Stresses. Figure 4-7 fras, that report presents the results of inferring deliections fro. stresses, This inforssat lun was to aid in the design of hatch c,,vera which are sensitive tu torsional-induced n t r es ses
a
Minimal data are presented in titis report;
io fact, only a minimal
amount of data have been reduced to date.
This ix substantiated by
Table B-1 presented in Appendix (B). Additional data reduction is required before the dato would be in a form useful to s designer or researcher.
s
The data obtained from the calibra- Lion expertisent was used to aid in the validation of the ABS unite- element program DAISY.
The
dis-cuss ion of that report (Reference 24) presents an evaluation of ths calibration experiment results.
s
This la strictly a data formal presentation report.
The data
presented in the report do not contribute to validation efforts,
s
*
Port
16
Stbd
Reading not taken due to safety considerations.
Figure 4-2 Hatch Deflection Measurements from the Calibration Experiment Performed on the SL-7 SEA-LAND McLEAN
Condition Direction Measurement
Cumulative Change 4 1-1 96' 4 3/4" 0 4 2-2 96' 4 9/16" 0 4 3-3 50' 5" 0 4 4-4 50' 4 1/4" 0 5 1-1 96' 4 5/8" - 1/8 5 2-2 96' 4 5/8" + 1/16 5 3-3 50' 4 3/4" - 1/4 5
4-4
-*
-*
6 1-1 96' 4 3/8" - 3/8 6 2-2 96' 4 15/16" + 3/8 6 3-3 50' 4 11/16" - 5/16 6 4-4 -* -* i 3 4 2 HATCH 7 2 4 3 iTA8LE 4-1 (cost 'dJ
EVALUATION OF THE SL - 7 RESEARCH PROGRAM Element :
PULl. SCALE INSTRiJNENTATION
Report
Titis
SSC No. Rei. Ho. Pub. Date
Contribution of h. Siudy in Achieving tfr SL -7 R.s.arch Program Goals
Structural Design Methods Sp.cilic to the SL- lind Conhaln.rihlps in G.n.rai
Measurement and Prediction of Ship Load, Motion end Stress Ralional Hull Glider Load CrIt.,Ia Analylis end O.v.Iopmsnt including Stalletical Enuluution Ot Oat.
Second Season Resulta froc Ship Rspnns
lostrueentation
Aboard the Si-1 Class Con- tsloership S.S
SM-LAND McLEAN
In North Atlantic Servite SI-7-9 Reference (9) 1976 Thtrd Season Results from Ship Response Instrumentation Aboard the St-I Class Con- talnership S.S. SEA-LAND McLEAN in North AtlantIc Service SI-i-IO Reference (IO) 1976 A Report on Shipboard Wave- height Radar Systee Si-7-i) Reference (Ii) 1978
s
Corents presented for Reference (8) apply. C-flmnents presented for Reference (8) apply. Stress date were recorded at the forward hatch cutout wi,ere fatigue cracks were observed. Ti,ene date are availahle and could be used for fatigue analysts and deoelopment of methods to anoi,i hatch corner fatigue damage.
However.
the data have not been reduced or analyzed to date.
e
Gonerents presented for Reference (8) apply.
e
Consiente presented for Reference (8) apply.
a
This report documents tite radar wave n,eter obtained from NRL and used
on
the
MclEAN.
The
report
presents a brief discussion on the required d-na analysIs needed to obtain a true wave height from a roving Bi,ip.
However, the specific
limitations of ti,e system were not I«,reseen at the system desIgn level.
e
Coents presented for Reference (Si apply. Sata were recorded while the MCLEAb was nettling on the blocks during drydcking.
However,
TARIR 4-i (conL'd)
EVALUATION OF THE SL -7 RESEARCH PROGRAM Element :
F1JLL-SCAI,E INSTRIJ)IENTATION
Report
Titi.
SSC No. A.t. No. Pub Data
Contrlbu Ion of Ib. Study In AchievingihaSl- 7 Ree.arch Program Goat.
Structural Design Methods Specific to the SI-land Containarships in Generai
Measurement and Prediction of Ship Load, Motion and Strass Rational Huit Girder Load Criteri. Analysis end Development including Statistical Evaluation of Data
Original Radar and Standard Tucker Wavemeter SL-) Container- strip i)ata Reduction and Correlation Sample SSi'-277
Reference (14)
1978
Wavemeter liais Reduction Method and initial Data for the Si,-) Conta loership SSC-218
Reference (15)
1918
Radar and Tucker Wavemeter Data fro. S.S. SEA-lAND McLEAN Voyage 32 - SL-7-16 Reference (16)
19/8
Voyage 33 - SL-7-i7 Reference (17)
1978
Voyage 34 - SI-J-l8 Reference (18)
1978
Voyagea 35 and 36E - SI-7-19 Reference (19)
1978
Modified Radar and Standard Tucker Wave.etec SL-) Container- ship hala SL-7-20
Reference (20)
1978
Radar and Tucker ijavemeter Data Eroe S.S. SEA-LAND KCLEAIIt
Voyage 60 - SI-7-21 Reference (71)
1978
Voyage 6f - SI-7-22 Reference (22)
1918
e
References (14) through (22) prevent data reduction procedures and the subsequent data reductinna.
The
TABlE 4-1 (cnnt'd)
EVALUATION OF THE SL - i RESEARCH PROGRAM Ei.m.nt
FULL-SCALE INSTRUMENTATION
R.port
Titi.
SSC No. Rel. No. Pub, Oit.
ContrIbution 01 the Study in Achilving 1h. SL -7 R.s.arCh Program Goal.
Structurel D.sign Methods Sp.citic to the 9L 7and Cont.ln.rshlpi In Gen.r.I
M.aeur.msnt end Prediction of Ship Load, Motion and Str.,.
Rational Hull Girder Load Criteri. Analysis and Development Including Sleti.licel EvaluatIon 01 Ost.
Results and Evaluation of the Si.-) Containership Radar and Tucker Wavemeter Data SIC-280 Reference (23) 1978
e
This report contains a detailed des- cription and evaluation of the wave- meter systems used on the SEA-LANT MtrLEAN. The author, (Dalnell), appropriately concluded:
The evidence strongly suggests that neither of
tite wave measuring
systems (Tucker and Radar) can be regarded as a standard by which the performance of the other may be judged. This la illustrated by typical com- parIsons of wavemeter systems shown let Figuren 4-3 and 4-4.
The conclusions
and recoomiendat ions of Reference (23) present
a discussion of how che
systems may he improved.
The
conclusione and reconmiendation are presented in the Sosinary of Reference 23 in Appendin (A).
e
lt
is unfortunate that the wave data
recorded on the SEA-LAND MclEAN were determined unreliable.
These datawerE
to be an integrai part of the total research program (outlined In SSC-2S7 Sl.-7-S) anti were a
necessary part of
the validation of analytical pre- dictions and model tests.
Recall
50 40
w w
i: 30 X 10 00 10 20 30 40 50 TUCKER F1TER 4 Rt1 (CORRECTED) FELT Figure 4-3ComparisOn cf ENS Estimates from the OWHS Radar with Corrected 4 ENS Estimates from the Tucker Meter:
All Intervals 0 10 20 40 50 TUCKER rETER 4 RuS (CC)(LCTED FEET 'igure 4-4
Comparison of 4 RNS Estimates from tIi
OWHS Radar with Corrected 4
RMS
Estimates from the Tucker Meter; Intervals Plotted are Restricted
to
T lose for which the Radar Spectrum Area above the Low-Frequency
TABLE 4-I (cont'd)
EVALUATION OF THE SL - 7 RESEARCH PROGRAM Element
FULL- SCALE INSTRUMENTATION
Report
Titi.
SSC No. Ref. NO. Pub. 0.1.
Contribution of the Study In Achieving the SI-7 Research Program Goals
Structurel Design Methods Specilic to the SI-7 end ConteIn.rshipa In G.n.r.t
Measurement arid Prediction ol Ship Load, Motion end Strega Rational Huit Girder Load Criteria Anetysis and Denetopment tnciuding Stetisticat Evaluation ot Dei.
Results uf the First Five 'Data Years' of Extreme Stress Scratch Gauge Data Collected Aboard Sea-Lands SL-7s SSC-286 Reference (25) 1979 Evaluation of SL-? Scratch Gauge Data Reference (31) September 1980
Tite authors of Reference (31) point out very appropriately that the scratches produced by the mechanical devices every 4 hours represent the sus total of the structurai response of many types of loads. Titis is illustrated in FiRtures 4-6 and 41, One scratch une can represent tite response from tite following types of lu,ads:
(con't)
s
This report presentv data analysis of the scratch gauges for each of the
8
shlpa
in
a
histo'
gram fore (see Fig.4-5).
This
data presentaI ion forsat is not readily co.patibie with the statistical evaluation techniques which require nome type of weather classification,
Of specific note
is tite fact that project records uf the weather conditions encnuntered were kept for only the first three seasons of operation for the SEA- i.ANt)HcI.FJ,N;
however, the scratch
gauges were operating on ali 8 ships of the class for a total of 7 years each.
There are weather
observai lites contained i,, the ships' log books for the other rases, bat as of this time that infoomar ion lias flot been released.
a
Tite
uni' iusi,,ns by Oliver (Ref. 31)
TABLE 4-1 (cont'd)
EVALUATION OF THE SL - 7 RESEARCH PROGRAM Elimini:
FIJLLSCALE 1NSTRLThIENTAT ION
R.port
Till.
SSC No. Paf. No. Pu b. D.l.
Contribution of h. Study in Achieving lh.SL- 7 Research Program Goat.
Structurai Dasigri M.thods Sp.cilic to (h. 5i- land Conhaln.rahlps in G.n.ral M.aeur.m.nt and Prediction of Ship Load, Motion end Stress
Rational Hull Girder Load Criteri. Analyuis and O.veiopm.nI including Stalleilcal Evaluation of Dita
Continuation of Reference (Il)
i.
Still-water bending due to weight And buoyancy.
-2.
WendIng due to the ship s own wave train.
J.
Wave-induced bending.
4.
Dynsmic loads, including elserting. whipping and springing.
5.
Thermal effects.
e
Since tite scratches do not represent the wave-induced bending moment alone, they are not appropriate for use as an alternative to more complex con- tinuous assessment sensors if the objective Is to calibrate analytically or statistically predicted structurai responses from wave-Induced loads only. of scratches lores a complete picture of the ship response from ail loads.
250 230 3300 2030 M 503 w Li
z
7G r 12 IP-fl--z698 PSI
40Ii7.
141RESOURCE -STBD DATA YEAR
3
ATLANTIC SCkATCH GAUGE 6S73A006 SUMMARY DATA YEAR 3 PACIFIC
327 OCCURRENCES
23I
3I1l 2ii
I'I''''i'''' i
5 10 15 20 25 30 35 40MAXIMUM PEAK TO TROUGH STRESSKPSI
H f000 psi
8 ro I I 4?I3I2pi4 I 2 I.i 'i'' ''r ''''1
5 10 15 20 25 30 35 40MAXIMUM PEAK TO TROUGH STRESS - KPSI
6046
OCCURRENCES 2500 2 1500 w L)z
w ct 10(X) 5OO 25cl 2c03 1 PSISUMMARY DATA YEAR 3 ATLANTIC
1156 OCCURRENCES 24 12 7 l29 10J6 I4
¿'3'
I 10 )5 20 25 30 35 40MAXIMUM PEAK TO TROUGH STRESSKPSI
L
il
SUMMARYTOTAL DATA YEAR 3
I'l 1627
II
e2'O
494 I 2841(---Ì000PSI
II
II ii
I '2e 4 24 24 3 eh.
5 lO IS 20 25 30 35MAXIMUM PEAK TO TROUGH STRESSKPSI
Figure 4-5
Histograms of Scratch-Gauge Data Measured on the SL-7 RESOURCE
7202 OCCURRENCES 000
Ií
L
i I 500 I 226o z
I Ill o I -494
The trace of the scratch gauge recording pen is often visible as the
paper advances every four
hours. The trace does
not necessarily arrive
and leave at the same point on the scratch.
Paper Tape Recort of Scratch Marks
11 Apparent / L.. single ex-treme sag
Jexcursion
-flare or bottom impact Range of most wave- induced strains andmean loading
varia t ions Evidence of extreme hogJexcursions
Character of the scratch marks in severe conditionsFigure +-6 Miscellaneous Details of Scratch Records
Maximum Positive Peak: Transient Stress From Flare Shock & Wave- Induced Load
Mean Stress Change: Ballast Shift
Maximum Negative Peak. Green Water Impact
TIME HISTORY OF STRESS
Mean Stress Change: Ship Changing Speed and Generated-Wave- System Loading
Figure 4-7 Illustration of Scratch Mark Equivalent
to
Complex Time History of Stress.
SCRATCH GAUGE
RECORD
i
Equivalent
Mean Stress Change:
Scratch Mark
TARLE 4-1 (cont'd)
EVALUATION OF THE SL -7 RESEARCH PROGRAM Element:
tjljtift. TESTINC TECHNIQUES
R.port
Till.
SSC No. Rai. No. Pub. Dal.
Conlribullon nl the Study In Achieving 1h. SL- i Research Program Goals
Structural DesIgn Method. Specific to the SL- iand Cont.ln.r.hlps ¡n General
Measurement end Prediction of Ship Load, Motion and Stress Rational Hull Girder Load Criteria Analyaia and Development Including Statistical Evaluation ot Data
Wave Loads in u Node! of the SL-7 Containership Running et Oblique Headinga in Regular Waves SSC-239 Reference (2) 1974 Verification of the RigId Vinyl Modeling Techniques SSC-259 Reference (6) 1976
a
The results of the (small) 1/140th scale model tests of the SL-) con- talnership were used prtnrarlly to aid in the validet ton of the SCORES corsputer program.
Further discussion
of the model test reaults is pre- sented io the evaluations of References (4) and (12). The model was small and self- controlled.
Some problems were
en-countered with the directional control of the model;
however. lt wan felt
by the inveatigetors that the dif- ficulties were uf secondary concern.
a
TIme measured heave of the model was suspect when results were analyzed due to a possible error in the calibration of the heave post possibly producing a heave response in error by a factor of two.
a
TABLE 4-1 (conid)
EVALUATION OF THE SL -7 RESEARCH PROGRAM Ei.m.nt:
NOVEl. TESTING TECHNIQUES
R.port
Titi.
SSC No. '
°
Contribution of h. Study In Achiseing 1h. SI-7 R.s.irch Program Goats
Structurai b.slgn Usthod. Specittc to the SL- land Cont.in.rship. In G.n.ril
M.asursm.nt and Pr.dlctlon of Ship Load, Motion and Str..,
Rational Hull Gird., bld Criteri. Anitysts and D.v.lopmsnt Including Statistical Evaluation of Dita
Continuation of Reference (6) SLructUral Tests of SL-? Ship Model Sic-269 Reference (lI) 1917
shown in Figures 4-21 and 4-22. The authors of Reference (6) also point out that both vinyl and steel models do not adequately represent areas of stress concentration and structural jolote.
a
TABlE 4-1 (cont'd)
EVALUATION OF THE SL - 7 RESEARCH PROGRAM Ei.m,.it:
WIDEL TESTING TECHNIQUES
R.poft
Titi.
SSC No. Ref. No. u
.
Contribution of 1h. Study in Achieving fha SI-7 R.sarch Program Goals
Structural Design Method. Specific Io the SL- land Contain.rships in G.o.ral U.asur.m.nt and Pr.dicllon of Ship Load, Motion and Sires.
Rational Hull Gird., Load Cril.ria Anslysil and Dsa.iopm.nI including Statistical Evaluation of Oaf.
Continuation of Reference (II) Capsizing Experiments with a Model of a Fast Cargo Liner in San Francisco Bay Reference (27) January 1972
end the vinyl structurai model described in Reference (6).
e
This program identified the possible benefits of open-water model tests for studying rare phenomena.
Traditionai
towing tanks have a Hefted capability of producing realtetic abort-created aeas of sufficient severity and duration of teat runs necessary to produce rare events that would be required, especially in following seas where the frequency of
wave
encounter is low. No indication was given rejative to the representative nature of wave spectrum esiating during testing in the San Francisco Bay as compared to open ocean wave spectrum.
a
Gages visible in this view
D
Gages hidden in this view-'- Rigid Vinyl Model Stress O Steel Model Stress
Stress Scale 1" = 1. i
Figure
4-8 - Comparison of SL-7 Stresses at Frame 178during Positive Torsion
3kEAR
FORCE(L)
-1 E)JDU.JG M O M E T(Ls-u4')
X T 10 30 6 6z 112 20 142 160 178 19 220 22 22 258 27 290 I I I tI/I
I I11H
PTFn
LHLb-
IL24
2.j-
3
19.219.222.2
LOADS
(Lbs)
suDate of Experinent 6 July 1972
Figure 4-9 Representative Loading Applied to the Steel Structural Model
30 311 342
3.2k
PO PT >-I DOk
2200
(4)
850
(2)850
+1
V'V (2.)tOO
(z)
PPO1T 31100
A
(z)
1100(2)800
22OO(4)
A
3000
/_crJu.0
800
IO 34 110-50
-300900
2(-toco
-1400
-1883
TABLE 4-1 (cont'd)
EVALUATION OF THE SL - i RESEARCH PROGRAM Ei.m.nl:
ANALYTICAL TECHNIQUES
R.porl
Till.
SSC No.
Contribution of lb. Study in Achi.ving lb. SI-7 Research Program Goals
Structurel D.UIgn N.thoda Specific to h. SL- land Contalnerships In O.n.r.l U.esur.m.nl and Prediction of Ship Load, Motion end Sir..s
Rational Hull Girder Load Criteria Analysis end Dsveiopm.nt including Stetistic.i Ewaluation ot Date
Structurai Analysis of SL-7 Containership Under Combined Loading of Vertical, Lateral and Torsional Moments Using
The structural analysis of the SL-? using the finite-element computer program was used to generate data to infer s relationship between hatch deflection and predicted stresses at the transverse girder and longitudinal girder intersections, These data as depicted In Figure 4-10 wece intended co provide a relation- ship between hatch dIstortions. measured et rennes in the seaway on
the McLEAN. and the seaway condltiona
producing the loadings,
However,
the relationships were not
pursued in the open literature beyond the information presented in Reference (6) and represented here in Figure 4-iC
e
The su-esa distribution
at
the forward hatch corner Cutouts resulting from vertical bending and lateral and torsional bending. Examples of the acrees diatribut lone nr the hatch corner cutouta are shown in Figures 4-Il and 4-12.
a
The structural analysis presented in Reference (6) represented the first of a serles of steps to exercise the ABS. DAISY finite-clement computer program.
As a first step it
pro-duced data that aided in the selection of strain gauge locations on the McLEAN.
Hor.ev.r. this information
is limited in total scope.
a
The report does not discuss how the loading for che contalnership was developed.
A description of the
procedure would be most useful for others contemplating a similar finite-element analysis.
even though
lt use not a primary objective nf the report.
T
MAT4 -- OPENING1 1.0 100 200 300400
500
r17 ¡n KG!CMZ
1.5 'J o .04 >_ .02 .01 o 2.0 E 1.0 1020
30 40 50 d'b irK/CM1
r4A1OPEL
J I I I I I 10 20 30 40 50 60 70-
IP\KG/CM1Figure 4-10 Hatch Distortion vs. Stresses in Transverse Box at Fr. 178, Port
SIde-Section B Due to Torsional and Lateral Moments For the SL-7 Containership
STRES3 SCALE
k4fri'
- LONGITUDINAL STRESS
--- .HEAR STRESS
Figure 4-11
Stress Distribution Due to Wave-Induced Vertical Bending Fr. 142-146
Second Loading
Case
37RE53 SCALE LONGITUDINAL. STRESS
- - - SHEAR STRESS
Figure 4-12
Stress Distribution Due Lateral Bending and Torsional Moments Fr. 142-146
Second Loading Case AT VR4MZ Iii: AT P'AM2 l4*: t J 727 LA7EIALMOAIZNT. 2,Ç00 C.. .1H14* POACL sai t... L TOMSIONAL MOMEMT
7 000 t
LATIIAL £1.IA*-700
oß3 MA/N DECX MAIN O(CIÇ P. 14*'1,4'
f1.141 4 l4TABLE 4-1 (contd)
EVALUATION OF THE SL -7 RESEARCH PROGRAM Element
ANALYTICAL PREDICTIONS
R.port
Title
SSC No. R.f. No. Pub. Oat.
Contribution
of 1h.
Study In Achieving the SI-7 Research Progrem Goals
Structurel Design Methods Specific to the SL- 7.nd Contalnershipi in Geoarel
M.esu,.m.nt end Pr.diction of
Ship
Load. Motion end Str...
Rellonet Hull Girder Load Criteria Analysis end Development including Siatieticei Eveluelton of Data
Theoretical Estimates of Wave Loada on The SL-7 Contalnershlp in Regular and Irregular Sea8 SIC-246 Reference (4) 1974
s
The comparisons of model tent data (Reference 2) and SCORES computer program results were not as good as had been hoped. Examples of con- pansons for head, quartering and following seas appear in Figuren 4-13 through 4-16. The lach of agreement between theory and experiment vea attributed to the following factorn 1. Influence of higher forward speed oí the containership (Froude number effect).
2.
In following seas, the theory is considered to be very tentative due to the low encounter frequencies.
3. Lateral plane wave loads are
highly dependent upon adequate repreaentatlon of ship roll response with non-lInear roll damping, which is not represented iii a linear/ship motions program.
i
50000 40000 30000 20000 10000 360 270 180
Vertical Moment Amplitude Wave Amplitude Ft . -Tons Ft. o o N N 35 N N o N
Wave Length/Ship Length
Figure 4-13 Midship Vertical Wave Bending Moments and Wave Phase Lag, 180° Heading
Heavy Displacement o Experiment (V-30 KTS) Experiment (V-25 KTS) Theory (V-25 KTS) Theory (V"30 KTS) Q o S-I I I I i I I I 0 .2 .4 .6 .8
1.0 1.2
1.4 1.6 1.8 2.0 Wave Length/Ship Length360 270 - 180 - 90 36 o o 1.0 1.2
1.4 1.6 1.8 2.0
Wave Length/Ship LengthI I I I
°
I I o1
.2 .4 .6 .8 1.0 1.2
1.4 1.6 1.8 2.0
Wave Length/Ship Length
Figure 4-14 Midship Vertical Wave Bending Moments and Wave Phase Lag, 0° Heading
50000 40000 30000 2000Ù 10000 Ft.-Tons o o Theory (V=25K1 Theory (V-30KI & Ft. I-/ I
-Vertical Moment Amplitude Light Displacement
Jave Amplitude
o Experiment (V25KI Experiinent (V=30KI
5000 4000 3000 2000 1000 360 270 180 .: 90 I I i I I I I t I 0 .2 .4 .6 .8 1.0 1.2 1.4 1.6 1.8 2.0
Wave Length/Ship Length
Figure 4-15 Midship Torsional Wave Bending Moments and Wave Phase Lag, 30° Heading
Torsional Moment Amplitude Wave Amplitude
37
1.0 1.2
1.4 1.6 1.8
2.0Wave Length/Ship Length
Heavy Displacement Experiment (V=3OKTS) OExperimerit (V25KTS) Theory (V=25KTS)
___Theory (V=3OKTS)
o o o oCn
Wave Length/Ship Length
Figure 4-16 Midship Torsional Wave Bending Moments and Wave Phase Lag, 240° Heading
38
I I
o
I
.2 .4 .6 .8 1.0 1.2
1.4 1.6 1.8
2.0 Wave Length/Ship Length360
270 o o o
180
J I I I t i I i I I
0
.2
.4
.6
.81.0 1.2
1.4
1.6 1.8
2.0
Torsional Moment Amplitude Wave Amplitude Heavy Displacement Ft. -Tons o Experiment (V=25KTS) 5000 Ft. o Theory (V=25KTS) 4000 3000 o 2000 1000 o
1A81.E 4-1 (conE 'rl)
EVALUATION OF THE SL-? RESEARCH PROGRAM Element
ANAlYTICAL TEQINIQUES
Riport
Titi.
SSC Ho. Ref. No. Pub. Dai.
Contribullon 01 h. Study In Achieving 1h. SL-? R.siarch Program Goals
Structurel Osaign Method, Specific to the L.- 7 atd Contain.rships In Generai Measurement and Prediction of Ship Load, Motion md Str.,.
Rational Hull Girder Load Criteri. Analysis and Development Including Siatieticai Evalumlion of Dii.
A Correlation Study of SL-7 Containership Loads and Mottons - Model Tests and Computer Simulation SSC-271 Reference (12) 1911
This project estended the basic theory presented in Reference (4)
in several
areas which include: 1.
Incorporation of close-fit techniques for deveiopaent of hydrodynamic coefficients instead of the Lewis-for, method originally employed.
2.
Incorporation of speed-dependent terms in the equations of motion.
3.
Influence of rudder deflection in ship structural response.
4.
Incorporation of the effects of surge in the equations of .otion.
5.
InvestIgation into the effects of non-linear role in ship response. Examples of the influence of each of these extensions to the SCORES theory are presented in the report.
Several
of tite figures are represented here and indicate an improvement in predic- Lions for sidxhtp vertical bending and midship torsional bending.
(See
Figures 4-17 through 4-20.)
a
The effects of model testing proce- dures on stoici response were Indicated anti would benefit future comparisons between model tests and theoretical predictions.
TABLE 4-L (contd)
EVALUATION OF THE SL-1 RESEARCH PROGRAM Ei.m.nt :
ANALYTICAL TECHNIQUES
R.port
Titis
SSC No. Rel. No. Pub. Oat.
Contribution of h. Study in Achieving th.SL- 7 Research Program Goals
Structurai Design Methods Specilic to (h. SL- land Contalnerships in Generai
M..su,em.n( and Prediction ol Ship Load, Motion and Stress Rational Huit Girder Load Criteria Analysis and Development Including Statistical Evaluation ot Data
Continuation of Reference (12)
it was recoonended that larger models and better test apparatus for the easorement of response of the model in oblique seas be uBed. At
this stage of development, the
SCORES computer program represented the state of the art in predicting 8hip toad and response.
The
50000
360
210
I 0
90
VERTICAL IOMMT AMPL lIUDE WAVE AMPLITUDE
d
41 23 ET. HEAVY 30 ET. LIGHT 25 ET. LIGHTFigure 4-17 Midship Vertical Wave Bending Moments and
Phase Lag, 1800 Heading
O 25 ET. HEAVY 0' 3 ET. HEAVY 2', ET. LIGHT 30 ET. LIGHT THEORY. 30 ET. HEAVY UISPLAC1MIIt DI Sri V0I9ENI DISPLACEMENT DIO PL AC EIlEN r .8 1.0 1.2 1»
WAVE LENGTH/SNIP LENGTH l.a 2.0
.8 1.0 1.2 l»
t 0000 363 070 ¡$0 ¿5 (T. HEAVY 90 FT. -TONS FT. o PHFS( LAC DEC. 30 (T. HOAVY 30 (T. LIGHT
42
0' o o 25 (T. HEAVY 25 (t. LIGHT I I I I I I I t .6 .3 1.0 1.2 I». ¡.6 ¡.3 2.0WAVE LCNGIH/SHIP LENGTH
I I I I I
..
.6 .0 ¡.0 1.2 I.I .0 1.3 2.)WAVI LENGtH/SNIP L(HÇ.T14
Figure 4-18 Midship Vertical Wave Bending Moments and Phase Lag, 00 Heading
0P0R1I3NT
O 2s (T. IIOAVY PISPLA(ttflpfl
0 30 (T. HEAVY DIc0rp(
VITICAI MQMSWT AHPIJIUO( A OS (T. LIC.H1 DISPLACEM5IT
WAV( AIPLITUO( 30 (T. LI(HT DISPLAC(IQT 000 o .0000 30000 70000 0'
2
O
PHASE LAG 00G. 270 'SO 90'VC*TICAL MOMENT AMFUTUDE WAVE AMPLITUOE p000
I i t i I t I I t
.2
.'
. S LO t.& I.II
1.0 Z.'WAVE LENGI
Figure 4-19 Midship Vertical Wave Bending Moments and Phase Lag, 300 Heading
43
EXPEE M0T
O¿S OT. HEAVY DISPLACEMENT
2O KT. HEAVY DISPLACEMENT 2S Kl. LIGHT DISPLACEMENT 43O Kl. LIGHT DISPLACEMENT
