PRINCIPLES OF NAVAL ENGINEERING 



INCLINING EXPERIMENT, U. S. S. MIDDLETomL. 



IShMt ...,lS...tI....<l.?_...l 



CROSS CURVES OF STABILITY 

 Axis «uumfld .^ f««t above bu« Hr 



V»..l con.id.r«l w.l.,.ti,ht .. ..FOBECAST;^ DECK, 



Taken from Plan No. 



BuShips No. 



8.58 



Figure 3-14. — Cross curves of stability. 



included on the cross curves form (fig. 3- 

 14). 



Next, the corrected values of GZ for the 

 various angles of heel shown on the stability 

 curve (A) in figure 3-15 should be found and 

 plotted on the same grid to make the corrected 

 stability curve (B) shown in figure 3-15. 



When the values from 10° through 80° are 

 plotted on the grid and joined with a smooth 

 curve, the corrected stability curve (B) shown 

 in figure 3-15 results. The corrected curve 

 shows maximum stability to be at 40 ° it also 

 shows that an upsetting arm, rather than a 

 righting arm, generally exists at angles of heel 

 in excess of 75°. 



THE INCLINING EXPERIMENT 



The vertical location of the center of gravity 

 must be known in order to determine the stability 

 characteristics of a ship. Although the position 

 of the center of gravity as estimated by calcula- 

 tion is sufficient for design purposes, an accu- 

 rate determination is required to establish the 

 ship's stability. Therefore, an inclining experi- 

 ment is performed to obtain a precise measure- 

 ment of KG, the vertical height of G above the 

 keep (base line), when the ship is completed. 

 An inclining experiment consists of moving one 

 or more large weights across the ship and 

 measuring the angle of list produced. (See fig. 

 3-16). This angle of list, produced by the weight 

 movement and measured by means of a pendulum 



42 



