PRINCIPLES OF NAVAL ENGINEERING 



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MACHINERY 

 FOUNDATION 



147.18 

 Figure 2-14.— Deep floor assembly for 

 machinery foundations. 



Stern Structure 



The aftermost section of the ship's structure 

 is the stern post^ which is rigidly secured to the 

 keel, shellplating, and decks. On single-screw 

 ships, the stern post is constructed to accom- 

 modate the propeller shaft and rudder stock 

 bosses. Because of its intricate form, the stern 

 post is usually either a steel casting or a com- 

 bination of castings and forgings. Inmodern war- 

 ships having transom sterns, multiple screws, 

 and twin rudders, the stern post as such is diffi- 

 cult to define, since it has been replaced by an 

 equivalent structure of deep framing. This struc- 

 ture (fig. 2-17) consists of both longitudinal and 

 transverse framing that extends throughout the 

 width of the bottom in the vicinity of the stern. 

 In order to withstand the static and dynamic loads 

 imposed by the rudders, the stern structure is 

 strengthened in the vicinity of the rudder post by 

 a structure known as the rudder post weldment. 



147.19 



Figure 2-15.— Bulbous-bow configuration. 

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