PRINCIPLES OF NAVAL ENGINEERING 



dimension, no single drawing of a ship can 

 give an accurate and complete representation 

 of the lines of the hull. In naval architecture, 

 a hull shape is shown by means of a lines 

 drawing (sometimes referred to merely as the 

 lines of the ship). The lines drawing consists 

 of three views or projections— a body plan, a 

 half-breadth plan, and a sheer plan-which are 

 obtained by cutting the hull by transverse, 

 horizontal, and vertical planes (fig. 2-28). The 

 use of these three planes to produce the three 

 projections is illustrated in figure 2-29. 



147.28 

 Figure 2-29.— Half-breadth plan, body plan, and 

 sheer plan. 



In addition to using transverse, horizontal, 

 and vertical planes, ship designers frequently 

 use a set of planes known as diagonals . A 

 diagonal plane is illustrated in figure 2-30. 

 As a rule, three diagonals are used; these are 

 identified as diagonal A, diagonal B, and diag- 

 onal C. Diagonals are frequently shown as 

 projections on the body plan and on the half- 

 breadth plan. 



23.195 



Figure 2-30.— Diagonal plane. 



23.192 

 Figure 2-31. — Transverse planes and body plan. 



30 



