PRINCIPLES OF NAVAL ENGINEERING 



11.30(147)A 

 Figure 2-8.— Angle, I-beam, tee, bulb 

 angle, and channel frames. 



WELO' 



(SHELL OR 



BULKHEAD) 



FRAME BAR 



REVERSE BAR 



11,30(147)B 

 Figure 2-9.— Built-up frames. 



SOLID WEB 



147.14 

 Figure 2-10.— Web frame used in wing 

 tank construction. 



Both intercostal and continuous frames are 

 shown in figure 2-12. 



A cellular form of framing results from a 

 combination of longitudinal and transverse 

 framing systems utilizing closely spaced deep 

 framing. Cellular framing is used on most 

 naval ships. 



MAIN DECK 

 STRINGER 



LONGITUDINALS 



VCL 



BILGE 

 KEEL 



LONGITUDINALS 



KEEL 



147.15 



Figure 2-11.— Basic frame section 

 (longitudinal framing). 



In the bottom framing, which is probably 

 the strongest part of a ship's structure, the 

 floors and keelsons are integrated into a rigid 

 cellular construction (fig. 2-13). Heavy loads 

 such as the ship's propulsion machinery are 

 bolted to foundations which are built directly 

 on top of the bottom framing (fig. 2-14). 



Double Bottom 



In many naval ships, the inner bottom plat- 

 ing is a watertight covering laid on top of the 

 bottom framing. The shellplating, framing, 

 and inner bottom plating form the space known 

 as the double bottom . This space may be used 

 for stowage of fresh water or fuel oil or it 

 may be used for ballasting. 



The inner bottom plating is a second skin 

 inside the bottom of the ship. It prevents 

 flooding in the event of damage to the outer 

 bottom, and it also acts as a strength member. 



Stem and Bow Structure 



The stem assembly, which is the forward 

 member of the ship's structure, varies in form 



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