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

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-68-(b)(c)(d)(e)(f)(g)(h)(i)(j)At least two fire pumps are required, located in separate spaces,each capable of delivering water at the two highest points in theship at SO pounds per square inch.Hose and hydrant sizes shall be 2-1/2 inches, with 7/8 inch nozzleand SO foot length of hose,or, a 1-1/2 inch siamese hydrant withsingle hose, 7S feet long with 5/8 inch nozzle.Fire hydrants shall be of sufficient number and so located thatany part of the vessel, other than the machinery spaces, accessibleto persons on board while the vessel is being navigated, andall cargo holds may be reached with at least two streams of waterfrom separate outlets, at least one of which shall be from asingle length of hose. In main machinery spaces, all portionsof such spaces shall be capable of being reached by at least twostreams of water, each of which shall be Trom a single lengtlnofhose from separate outlets.Vessels engaged exclusively in the carriage of grain or coal inbulk, need not be fitted with a fixed carbon dioxide system inthe cargo h~s.A fixed carbon.dioxide or other approved system shall be installedin all lamp and paint lockers.A fixed carbon dioxide system shall be installed in all spacescontaining internal combustion main propulsion machinery andauxiliaries of 1,000 ~HT or greater or their fuel oil units,including purifiers, valves and manifolds.If an enclosed ventilating system is installed for electricgenerators, a fixed carbon dioxide system shall be installedin such system.Spaces which are protected by a carbon dioxide system and arenormally accessible to persons on board when the vessel is beingnavigated, other than paint and lamp lockers, shall be fittedwith an approved audible alarm in such spaces which will beautomatically sounded when the carbon dioxide is admitted tothe space.Hand portable and semi-portable fire extinguishers shall befitted of the type and number and in the locations specified.Livirw and Working Areas and Stores Spaces - It is considered that therequirements outlined above are sufficient for the aluminum ship in theseWeas.Mach.nery Spaces - Within the machinery spaces, consistent with theprotection for the aluminum structure outlined previously, the requirementsnoted above are considered the minimum necessary to afford protection.Additional &tection devices together with a fixed foam system would providea greater margin, provided that it can be reconciled against the additionalqost involved.Cargo Spaces - For steel bulk carriers engaged in grain or coal trade,no detection or fixed extinguishing system is presently required in the
-69-cargo holds. This is assumed to be based on the premise that if a fire didstart the provision of two fire hoses would permit sufficient fire control,together with the fact that steel does not lose its inherent strength inthe face of an average fire. For some cargoes and arrangements, these fixedsystems may not be effective.The ignition temperatures of the dusts of the various types of bulkcargo vary approximately between 6S0 degrees F to 9000 degrees F. Thus apotential fire in the cargo spaces can not be disregarded. In view of themaximum temperature restriction of aluminum, this warrants the installationof a detection system within the cargo holds. A temperature rise sensingsystem would probably prove to be the most satisfactory.In addition to the conventional cargo hold fire extinguishing system,an inerting system is recommended for all cargo spaces. This system couldutilize either nitrogen or carbon dioxide, and would be activated whenpotentially dangerous cargoes are carried. such systems are presentlyincorporated in a number of oil tankers to reduce the risk of explosion.The cargo holds must be gas-freed prior to unloading cargo, so that menmay safely enter the hold, thereby requiring the installation of largesuction fans serving the holds. In this regard, nitrogen offers an advantagein that it is slightly lighter than air and would tend to risenaturally from the hold when the hatch covers are open. However, thistendency of gas to rise would necessitate special techniques to maintain asatisfactory dist~ibution of nitrogen throughout the cargo, such as circulatingfans or continual bleeding of additional nitrogen at the lowestlevel of the hold. Carbon dioxide, being heavier than air, would be moredifficult with regard to gas-freeing the hold, but would satisfactorilydistribute itself throughout the cargo without resupply or recirculation.Neither gas would appear to be harmful to the range of cargoes beingconsidered.There are a number of umknowns concerning an inerting system such asthat proposed~ which preclude an evaluation of its cost. These include suchfactors as the required concentration of inerting gas to maintain a satisfacto~level of fire protection, the residual coricentration which couldremain after gas-freeing the hold, recirculation requirements and so forth.The solution to these problems is beyond the scope of the present study, butwarrants further consideration.An alternative which might be preferable to an inerting system wouldinclude a high-capacity carbon dioxide smothering system in conjunction withfire detecting equ!cpment of improved sensitivity. This system would incorporatethe following features:o Sufficient quantities of carbon dioxide to selectively flood a~hold, or the engine room, with a high concentration of gas.o A gas delive~ system which would insure rapid flooding of thespaces and even distribution throughout the space.o A detection system sensitive to rate of temperature rise and toultra-violet emissions from open flame.
Page 5:
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
Page 26 and 27:
-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 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 88 and 89: -78-Other Piping Systems and Valves
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
Page 138 and 139:
-128-~gE1+0102030- .. ..—405060
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ectintyclassification4KEYWORDSROLEL
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SHIP STRUCTURE COMMITTEE PUBLICATIO
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