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

-61-(b)(c)Bulkheads of galleys, paint and lamp lockers and EmergencyGenerator Room.Stair towers, elevator, dumbwaiter and other trunks.In summary, it must be concluded that all aluminum structures, specifiedto be of ‘]AII-Oconstruction, must be capable of withstanding the passage ofsmoke ard flame for a period of one hour while restricting the maximumtemperahre of the aluminum to 400 degrees F.Fire Test of Aluminum Construction - An extensive test program of representativeinsulated aluminum bulkhead and deck assemblies is presently beingconducted under the auspices of the Fire Test Ad Hoc Subgroup of Task GroupHS-6-1 (Aluminum) of the Society of Naval Architects and Marine Engineers(SNAME). Reference (67) is a test report on the first bulkhead test by theNational Bureau of Standards dated June 1~, 1967. Ten additional bulkheadand ceiling configurations are now in the process of fabrication for testingduring 1970. From these tests it will be possible to establish factualcriteria for the protection of aluminum structures within the living, workingand stores spaces.In addition to the SNAME test maw smaller tests have been conductedby materials manufacturers. Unfortunately, the results of these tests areof a proprieta~ nature. However, while these smaller tests lack officialGovernment approval they do nevertheless contribute valuable informationtowar~ eventual solution of the problem of fire protective aluminumconstruction.AREAS REQUIRING PROTECTIONLiving, Working and Stores Spaces - A study has been made of the living,working and stores spaces of a steel and equivalent aluminum bulk cargo ship,similar to the MV CHALLENGER, and built in strict accordance with currentU.S. Coast Guard rules. The study included the complete after deckhousedown to and including the underside of the Upper Deck.The construction utilized to afford the required protection is basedupon tests, where available, or the construction considered most suitable atthis time, based upon past experience, pending confirmation by testmethods. In most cases, a conservative approach has been taken in order torealistically approximate the maximum additional cost and weight that mightbe required.For both steel and aluminum ships, the stateroom and living spacedivisional bulkheads and the house side lining will be identical, i.e., 7/8inch thick free standing marinite with steel “H” posts and joiner shapes withinsulation if necessary. The normal application of thermal insulation on thesurfaces of air-conditioned spaces results in an added degree of protection.ID general, the aluminum bulkheads requiring additional protection canbe grouped in the following categories:(a)(b)The exposed surfaces within stair-towers.The engine room side of the machinery casing.