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

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TABLE 12 Aluminum Bulk Carrier - Summary of Ceilings, Insulation andDeck Covering in Living, Ilorking and S~o~es SpacesSteel ShipAlum. ShipUpper Lower Lb/ Lb/ Sq ● AddlSpace Space Insul. Sheathg Sq.Ft. Iklsul. Sheathg Sq.Ft. Ft. AlumOpen Air Cond. 2rf\~ff-1# 3/16” 2.6 2!1/~f!-6# 3/16J’ 3*7 6,188 6,Deck Spaces Mar.Ven Mar.VenOpen Refrig. 8J)/12Jl-1# 1/4JJ 8.9 811\1211-~# 1/~II 8.9 5’32Deck Spaces Reeferite ReeferiteOpen Machy 21i/111-3# Sht. 2.6 2t!\4fI-6# Shb. 4.6 685 1,Deck Casing wt. Met.Air Cond. Galley ~11 - 1# Sht. 2.2 411 - 6# Sht. 3.92 368Spaces Met. Met.Air Cond. Air Cond. None 3/161’ 2.3 2’1\I’1-6# 3/16“ 3.7 7,6f5h 10,Spaces Spaces MarVen I%r.VenAir Cond. Non-Air 211/lIl_l# Sht . 2.14 2f1/~!l-6# 3/16“ 3*7 2,190 3,Spaces Cond.Spaces Met. Mar.VenAir Cond. Pantry 411-1# Sht. 2.2 41! - 6# Sht . 3.92 785paces Met. Met.Cpen Emer. 21t/lIl_~# Sht . 2.I4 2!I\-l If-6# Sht . 3.25 190Deck Gen. Rm. Met. Met.Stores Steering None None 0.0 2JI/lH-6# Sht. 3.25 I,240 4,Spaces E@. Rm. Met.3tores,AC Machy 6N - 1# Sht . 2.42 6I! - 6# Sht* 4.92 4,253 10,% Service Casing Met. Met.3pacesTotals - Ceiling and Insulation 23,388 37,Total - Deck Covering 26,
.65-Machineq Spaces - Reference (68) lists 24s fire casualties on allclasses of ships, of which only four were on bulk carriers. Three of thefour fires originated in themachineryspaces and one in the accommodationspaces. Of those occurring in the machinery spaces, two were the resultof fuel oil fires while combustible materials restite’din the accommodationspace fire. This agrees with the expected assumption that these two t~esof combustibles are the primary sources of incipient fires, and that theselocations must therefore be provided with the maximum protection againstfires.Within the machine~ space, the most serious problem is the protectionof the exposed aluminum structure to prevent the passage of smoke and flameand to restrict the maximum temperature of the aluminum to 400 degrees Ffor the required one hour time interval. The overriding requirement is themaximum temperature restriction in the presence of fire, since if this canbe accomplished, the structure will prevent the passage of smoke and flame.One potential solution might be the use of sprinklers to form water wallson the vertical surfaces and the underside of the flats. However, thismethod is incompatiblewith an oil fire. A fixed fog system might be consideredbut to date there have been no physical tests to evaluate the timetemperatureresults of either of these proposals. A simple solution wouldbe to constmct the machinew space enclosing structure of stieel. This,however, poses additional problems of added weight, connection of incompatiblemetals, and differential coefficients of expansion. For many localstructures, such as machinery flats and small tanks, the use of steel inlieu of protected aluminum would appear to offer significant cost savingswithout a major weight penalty. Various types of fire-retardant intumescentpaints are available, but these are p~imarily used to retard the sPread offire rather tha to restrict the temperature rise on the surface to whichthey are applied for any appreciable time duration.Of all the methods considered, the one chosen to best provide thedesired protection to vertical surfaces and the crown of the machinery boxis the application of a suitable thickness of insulation, sheathed with metalto protect the insulation against injury and abrasion.The surface of tank top, while still requiring the same degree of protection,presents a rather different problem due to personnel access and abrasionfrom the movement of equipment. Of all the available materials considered, acomposite construction consisting of an approved cellular glass incombustiblematerial, expanded metal, .%bkote No. 1 and a magnesia aggregate topping similarto MIG-11-2313Lhas been selected as the optimum after due consideration ofweight, cost. abrasion, resistance, oil spillage, good housekeep~ng and otherconstraints.Table 13 gives the approximate areas in each category together withthe anticipated approximate added weight to protect the aluminum.While not considered in detail at this time, other items that must bedealt with are structural stanchions and webs in the machine~ spaces,together with exposed areas of main and auxilia~ machine~ foundations.It is also necessa~ to offset the deleterious effects of heat tramfer,
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 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 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
Page 140 and 141:
ectintyclassification4KEYWORDSROLEL
Page 142:
SHIP STRUCTURE COMMITTEE PUBLICATIO
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