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

More documents

Recommendations

Info

Rudder Assembly -carrier should be madethe following reasons:-72-The rudder and rudder stock of the aluminum bulkof steel, similar to that of the steel ship, for(a)(b)(c)An alwminum stock would have an excessively large diameter, tosuit torsional and bending loads, which wo-dd r=sult in anunfavorable aspect ratio for the rudder. In addition, steelsleeves would be required in way of the bearings to resistabrasion. Therefore a high-strength steel stock is consideredmore practical.The use of a steel stock dictates that the remainder of therudder be steel, to avoid problems of attachments of dissimilarmetals.The use of a steel rudder minimizes abrasion and vibrationproblems.The rudder stock should be isolated from the hull by the use of micarta orphenolic stave bearings. A cathodic protection system is also required,as discussed later. Details of the rudder bearing attachment to the hullwill be similar to Figure 14.//’ /“ /J1‘\ ‘\ \ \\’\ \‘~///“ ‘///////5I“I.=”:” .II!1—-..,— _~—-l 1 —.—FIG. 14 Stern Tube & Propeller Details M. V. C7mZZmgw
-73-Sea Valves - The selection of aluminum alloys for the sea valves andshell connections is subject to specific approval by the American Bureauof Shipping and U. S. Coast Guard.hAmAmerican Bureau of Shippi~follows:Rules - Article 36.2S.S on Page 249 of the- 1969 Rules is quoted for ready reference as1136.25.5 Materials for Shell Valves and Shell Fittings - All shellvalves and shell fittings required by this Subsection are to be ofsteel, bronze or other approved ductile material. Valves ofordina~ cast iron or similar material are not acceptable. Allpipes to which this subsection refers are to be of stieelor otherequivalent material, subject to special approval.”.— U. S. Coast Guard - Marine Engineering Regulatio~ am Material Specifications,Subchapter F, CG-11~, Part ~6.~0-9~ Overboard Discharges andShell Connections, Subchapter F is quoted for ready reference:II(-f) Valves required by this section and piping system componentsoutboard of such required valves on new vessel installations orreplacements in vessels of 1~0 gross tons and over shall be of asteel, bronze, or nodular cast iron specification listed in Tables6.60-a(a). Lead or other heat sensitive materials having amelting point of l,700°F, or less shall not be used in suchservice, or in a~ other application where the deterioration ofthe piping system in the event of fire would give rise to dangerof flooding. Brittle materials such as cast iron shall not beused in such service.Where non-metallic materials are used ina piping system, and shell closures are required by this section,a positive closure metallic valve is required (see also Para.S6.60-2S) .11In addition to cast aluminum alloys, other materials such as cast 25per cent nickel - 20 per cent chrome and AISI 304 or 316 stainless steelcould be considered for the sea valves. This 2S nickel - 20 chrome alloyis marketed under several trade names, Craneloy 20, Walworth Aloyco A-20.25 Per Cent Nickel - 20 Per Cent Chrome alloy . has been used formany years on the Lykes Eros. Gulf-Pride and Clipper Class freighters forsea valve suction and discharge services with good success. These staintrim.less steel valves were fitted with monelproperties of this alloy:The following lists the(a) ChemicalCarbonManganeseSiliconPhosphorusSulphurNickelChromiumMolybdenumCopperPer Cent0.070.7 w.1.5 Max.0.04 IJ&x.0.04 k.28 tO 3019 to 212t033.5 to4.5
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 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 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
show all

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

Create successful ePaper yourself

Delete template?

Save as template?