Chapter 2-SHIP DESIGN AND CONSTRUCTION 



In most naval construction, light deck beams are 

 interspaced at regular intervals with deep deck 

 beams. Deck longitudinals are used to provide 

 longitudinal strength. When possible, the heavi- 

 est longitudinals are located at the center and 

 near the outboard edges. 



The outboard strake of deck plating which 

 connects with the shellplating is called the deck 

 stringer (fig, 2-11). The deck stringer, which 

 is heavier than the other deck strakes, serves 

 as a continuous longitudinal stringer, providing 

 longitudinal strength to the ship's structure. 



Upper Decks and Superstructure 



The decks above the main deck are not 

 strength decks on most ships other than CVAs. 

 The upper decks are usually interrupted at in- 

 tervals by expansion joints. The ejcpansion joints 

 keep the upper decks from acting as strength 

 decks (which they are not designed to be) and 

 thus prevent cracking and buckling of deck 

 houses and superstructure. 



Stanchions 



In order to reinforce the deck beams and 

 to keep the deck beam brackets and side frames 

 from carrying the total load, vertical stanchions 

 or columns are fitted between decks. Stanchions 

 are constructed in various ways of various mate- 

 rials. Some are made of pipe or rods; others 

 are built up of various plates and shapes, welded 

 or riveted together. The stanchion shown in 

 figure 2-20 is in fairly common use; this pipe 

 stanchion consists of a steel tube which is fitted 

 with special pieces for securing it at the upper 

 end (head) and at the lower end (heel). 



Bulkheads 



Bulkheads are the vertical partitions which, 

 extending athwartships and fore and aft, provide 

 compartmentation to the interior of the ship. 

 Bulkheads may be either structural or nonstruc- 

 tural. Structural bulkheads, which tie the shell- 

 plating, framing, and decks together, are capable 

 of withstanding fluid pressure; these bulkheads 

 usually provide watertight compartmentation. 

 Nonstructural bulkheads are lighter; they are 

 used chiefly for separating activities aboard 

 ship. 



147.22 

 Figure 2-19.— Deck beam and frame. 



BRACKET 



DECK BEAM 



STANCHION 



WELD 



147.23 



Figure 2-20.— Pipe stanchion. 



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