As part of its broad program of structural research into novel hull 

 structures, in conjunction with some of the newer high- strength materials 

 such as the HY-steels, the HY-titanium and aluminum alloys, and even the 

 fiber-reinforced plastics, the Model Basin is examining a broad spectrum 

 of the more promising geometrical configurations and construction ideas. 

 These include stiffened and unstiffened spheres, prolate spheroids, and 

 other shells of double curvature; bimetallic and other composite and 

 sheathed arrangements; sandwich construction; multilayered cylinders, 

 and multilayered spheres; "membrane" shells; and metal tape-wound and 

 filament-wound cylinders. These efforts include both analytical studies 

 and structural model tests. A number of these problem areas are also 

 being investigated by organizations outside the United States Navy, but 

 these studies are primarily under Bureau of Ships and Office of Naval 

 Research sponsorship. 



A complete discussion of the state of knowledge for these new hull 

 concepts is a presentation in itself so that it is beyond the scope of this 

 report. However, it is pertinent that some introductory remarks be made 

 on the subject. 



Let us begin by saying that in the range of the thicker hull structures 

 required to withstand the greater pressures of operation, it can be shown 

 that with judicious design evolved from rigorous mathematical theory, 

 there is probably very little difference in structural efficiency between 

 the unstiffened, the ring- stiffened, and the sandwich cylinder. This fact is 



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