Chapter 2-SHIP DESIGN AND CONSTRUCTION 



147.29 



Figure 2-32.— Body plan of a YTB. 



BODY PLAN 



To visualize the projection known as the body 

 plan, we must imagine the ship's hull cut 

 transversely in several places, as shown in 

 part A of figure 2-31. The shape of a transverse 

 plane intersection of the hull is obtained at each 

 cut; when the resulting curves are projected 

 onto the body plan (part B of fig. 2-31) they show 

 the changing shape of transverse sections of the 

 hull. 



Since the hull is symmetrical about the 

 centerline of the ship, only one-half of each 

 curve obtained by a transverse cut is shown on 

 the body plan. Each half curve is called a half 

 station . The right-hand side of the body plan 

 shows the forward half stations— that is, the 

 half stations resulting from transverse cuts 

 between the bow and the middle of the ship. 

 The left-hand side of the body plan shows the 

 aft half stations— that is, the half stations 



resulting from transverse cuts between the 

 stern and the middle of the ship. 



As may be inferred, a station is a complete 

 curve such as would be obtained if each trans- 

 verse cut were projected completely, rather 

 than as half a curve, onto the body plan. The 

 stations are numbered from forward to aft, 

 dividing the hull into equally spaced transverse 

 sections. The station where the forward end 

 of the designer's waterline^ and the stem 

 contour intersect is known as the forward 

 perpendicular, or station O. The station at the 

 intersection of the stern contour and the de- 

 signer's waterline is known as the after per- 

 pendicular. 



The station midway between the 



The waterline at which the ship is designed to float 

 is known as the designer's waterline. 



31 



