design considerations for aluminum hull structures - Ship Structure ...

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-78-Other Piping Systems and Valves - The bilge system for the proposedship would consist of a bilge main within the machinery space having theusual bilge suctions in the machinery space and two manifolds for the cargohold suctions. The cargo hold bilge suctions go forward through the innerbotiomsea water ballast tanks and enter the bilge wells placed at theafter eni of the holds.The selection of piping materials for bilge service within the seawater ballast tanks would be subject to the same restrictions as tieballast piping.An estimate of the material cost exclusive of the check valves requiredfor this service is shown in Table 1S. This estimate shows that the rnat.erialcost of Schedule ~~0aluminum pipe system is almost the same as the low-costSchedule 8(Iblack steel system.It is the~efore recommended that this portion of bhe bilge system bemade of aluminum provided it meets U. S. Coast Guard requirements.Thickness2440 Ft 11~]PipeAlum. Bhd Pen (S0)Alum. spoolsTABLE 15 Material Costs - Bilge SystemIn Ballast Tanks (Dollars U.S.)(Llo)Flanges (70)Ku (150)couplings(36)ScheduleScheduh40 805,967 5,6305,967 5,6301,8001,376 5063,i.120 1,014Galv.SteelAS3Schedul~806,7s06,7~o1,8007601,402Valves (10) ~ Not IncludeiCathodicProtec- I,720 I,720tiionITotalcost ]10,763 110,670/12,432FiberglassReinforcedPlastic PVC Lined%ondstrandttResistofIexor Equal+10,24810,2485392,52019413,68116,104Includ~d—8,29524,399Firemain - The steel hull ore carrier has a firemain system composedof 90-10 copper nickel alloy piping with bronze valves and fittings. Sincethe U. S. Coast (hard probably would not approve the use of aluminum alloysor reinforced plastic piping for fire service, it is recommended that the90-10 copper nickel alloy system be retained for the aluminum hulled orecarrier. Special precautions are necessary to insulate this material forthe aluminum structure. The detail of bulkhead and deck penetrationsthrough aluminum structure must be developed. However, there is goodexperiencewith this type of installation on the SS UNITED STATES.Oil Systems - Black steel is usually used in the construction of oilpiping systems. The U. S. Coast Guard will not approve the use of aluminumfor these systems because of ik low melting point. In addition, becauseof the non-conductivecharacteristicsof fuel oil and the need for the fireprotection provided by steel, it is considered that the fuel oil transferand service systems, both heavy oil and diesel oil should be of all steelconstruction. Since lubricating oil has similar characteristicsandrequirements as fuel oils, it is considered that the lubricating oil
-79-service, transfer and purifying systems should also be of all steel construetion.Special precautions are necessary where the steel piping penetratesthe aluminum structure.. .Diesel Engine Fresh Water Systems - The steel hull ore carrier hasthe diesel engine fresh water systems made of Schedule LO galvanized steelpipe. For the aluminum hull ship it is recommended that the same materialbe used for these systems, with special precaution to insulate the systemfrom the aluminum hull structure.Sea Water Systems Within the Machineq Spaces - The systems under considerationare sea water cooling service systems for all heat exchangers,clean ballast system, oily ballast system and bilge system.The steel hull ore carrier has the sea mater service systems withinthe machine~ spaces composed of 90-10 copper nickel alloy with bronzevalves and fittings. Because of U. S. Coast Guard Regulations, it isrecommended that these materials be retained for the sea -waterservicesystems in the aluminum hull ship. However, insulation of the entiresystem is required, particularly at the connections between the piping andthe sea valves. If the U. S. Coast Guard would approve the use ofaluminum for this service, it should be considered. However, it will bevery costly in comparison to the 90-10 copper nickel alloy system, primarilydue to the high cost of valves and fittings.The steel hull ore carrier ballast system within the machineqy spacesis of Schedule 80 galvanized steel pipe. For the aluminum hull ship it isrecommended that the ballast system within the sea water ballast tanks be offiberglass reinforced plastic. However, there is some question as towhether the U. S. Coast Guard will accept this material within themachine~ spaces. If the U. S. Coast Guard accepts the use of fiberglassreinforced plastic, tihiswill permit the use of standard materials forp~s and valves ard reduce maintenance costs. The second choice wouldbe aluminum pipe and valves. Since large capacity centrifugal pumps ofaluminum are not available, special pump connections with replaceablewaster pieces must be provided.The steel hull ore carrier bilge system within the machineqy spacesis of Schedule LO galvanized steel pipe. For the aluminum hull ship it isrecommended that the bilge system in the machinery spaces be of aluminum.This presents the same problem as noted above, namely, the requirement ofheavy waster pieces at the pump connections. However, in this case theywill be comparatively small (~ inch or 6 inch IPS) and their replacementis not too expensive. For this reason an all aluminum Schedule 40 pipingsystem is recommefied.The weather deck ard sanita~ drainage systems for the steel hull orecarrier are all made of galvanized steel Schedule 80 pipe. It is recommendedthat all aluminum construction be used for these systems in thealuminum hull ship, using Schedule LO aluminum piping to simplify the maqycorulectionsati structural penetrations.The tank venting system and sounding tubes for the steel hull orecarrier are all made of galvanized steel, Schedule 80 in way of the upperwing ballast tanks and Schedule LO for the remainder of the piping.Beciuse of the maw connections to structure and structure penetrationsof these s~stems, it is recommended that they be made of all aluminum con-
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CONTENTSI.. II.III.Iv.v.VI ●VII.I
Page 9 and 10:
LIST OF FIGURES(Cent’d)FIGURE NO.
Page 11 and 12:
I. INTRODUCTIONThis report summariz
Page 13:
art in fabricating and maintaining
Page 16 and 17:
MONTEROSSO GRANA /17VALGRANA / CARA
Page 18 and 19:
-8-Numerous references have been re
Page 20 and 21:
.10.TABLE 2. Mechanical Properties
Page 22 and 23:
TABLE 2 Mechanical Properties of Al
Page 24 and 25:
TABLE 3 Mechanical Property Limits
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-16-l?igures5, 6, 7 ati 8 present f
Page 28 and 29:
-18-ti-’”’-”-””””-L
Page 30 and 31:
-20-60 .r---.— ..,.— -——,L-
Page 32 and 33:
.22-each stress level, rate of load
Page 34 and 35:
-24-!Z456-H321 = 0.485083-H321 = 0.
Page 36 and 37:
-26-(c)Members with partial or cont
Page 38 and 39: -28-AllOyS 5083 and 54.56(~ content
Page 40 and 41: -30-The previous paragraphs have de
Page 42 and 43: -32-The problem of cargo hold abras
Page 44 and 45: -34-The question of residual stress
Page 46 and 47: .36-Each alloy was given a relative
Page 48 and 49: -38-GENERAL OBSERVATIONSFYior to a
Page 50 and 51: -40-The question of comparative imp
Page 52 and 53: -42-(d)(e)Poor quality welds due to
Page 54 and 55: -44-The ABS criteria noted above we
Page 56 and 57: -46-DNV would consider fatigue in e
Page 58 and 59: -48-is less, for the exposed side s
Page 60 and 61: Equation (2):-50-Hu1l SMa~um = Hull
Page 62 and 63: -52-Another aspect of vibrations wh
Page 64 and 65: -54-000000000Bottom Shell PlateSide
Page 66 and 67: -56-at the deck and keel. This stre
Page 68 and 69: -58-AT is the change inUT= Thermal
Page 70 and 71: -60-SUl@!ARYAll parties contacted f
Page 72 and 73: -62-(c)(d)(e)(f)T~e exterior side o
Page 74 and 75: TABLE 12 Aluminum Bulk Carrier - Su
Page 76 and 77: .66-INSUT.ATION AND SHEATHINGShell8
Page 78 and 79: -68-(b)(c)(d)(e)(f)(g)(h)(i)(j)At l
Page 80 and 81: -70-IIF.INSTALLATION OF SYSTEMS AND
Page 82 and 83: Rudder Assembly -carrier should be
Page 84 and 85: -74-(b)MechanicalTensile Strength 6
Page 86 and 87: -76-(e)The steel piping must be of
Page 90 and 91: -80-struetion for the aluminum hull
Page 92 and 93: -82-Large heavy type machine~ must
Page 94 and 95: suffers attack in an alkaline envir
Page 96 and 97: -86-REPAIRSObtaining proper repairs
Page 98 and 99: -88-The design of the midship s~cti
Page 100 and 101: -90-assuming the increase is applic
Page 102 and 103: LIGHT SHIP WEIGHT ESTIMATE-92-In or
Page 104 and 105: -94-TABLE 20 Aluminum Bulk Carrier
Page 106 and 107: TABLE 22 Trim and StabilityFull Loa
Page 108 and 109: -98-TABLE 24 Price of Steel Bulk Ca
Page 110 and 111: GaseNumber. . . -.,- .TABLE 27 Comp
Page 112 and 113: -1o2-TABLE 28CarriersComparison of
Page 114 and 115: 12 ---n..T.[T7%l,=LEGS IU ORF=ErY
Page 116 and 117: -106-such as iron ore, on two of th
Page 118 and 119: -108-7)is,zg~ gg~5e mzz~E’4E!~K2j
Page 120 and 121: -11o-(a)(b)(c)(d)Inerting system fo
Page 122 and 123: -112-fatigue, particularly in the p
Page 124 and 125: -114-2k* Installation of Systems an
Page 126 and 127: -116-LIST OF REFERENCES(7)Fatigue P
Page 128 and 129: -11.8-LLST OF REFERENCES(Cent’d)(
Page 130 and 131: -120-ADDITIONAL SOURCES OF INFORMAT
Page 132 and 133: -122-redistribution of the still wa
Page 134 and 135: -124-APPENDIX BEXCERPTS FROMRULES A
Page 136 and 137: -126-92.07-10(d)(~) Interior stairs
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-128-~gE1+0102030- .. ..—405060
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ectintyclassification4KEYWORDSROLEL
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SHIP STRUCTURE COMMITTEE PUBLICATIO
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