nor did the information for the selected basis models give any clear guidance. All the data 

 showed a progressive movement aft with reducing block or prismatic coefficient, resulting in 

 finer entrances for the models running at the higher speed-length ratios, as one would expect. 

 A linear variation of position of LCB with fullness was therefore adopted, as shown in 

 Figure 1. Although arbitrary, this line was in general a niean of the available data. Since 

 the effect of LCB position was the next point to be investigated in the program, this line 

 was considered to be an acceptable point of departure. 



c. Load waterline half-angle of entrance {Y^ ag) 



This angle varies from 7.0 to 43 deg, as shown in Table 2 and Figure 4. 



d. Sectional area and waterline coefficient contours 



The length of parallel body and its fore and aft position for the parent models with the 

 selected position of LCB are shown in Figure 4. 



The corresponding lengths of entrance and run (Lg and Lj^) were determined, each 

 divided into 10 equal intervals, and contours of cross-sectional area coefficients were plotted 

 to a base of prismatic coefficients of entrance and run respectively (Cp£ and Cp/j). These 

 contours are shown in Figures 5a and 5b. 



The body plans were treated in the same way; contours of waterline half-breadth 

 coefficients to a base of prismatic coefficients of entrance and run are given in Figures 6a 

 to 6 p. 



The positions of the centroid of volume of the entrance and run are shown in Figures 

 7 and 8 for different values of the respective prismatic coefficients. (Text continued on page iv-23) 







Cx 















— 











■>^ 







- 









K 



\ 



"^ 



■ — 



















^ 









Cp 







r 







^ 













/ 





^ 











/ 













/ 



-{' 













/ 



/ 



1-BP 











y 



/ 















^ 













0.60 0.65 070 0.75 0.80 



Ca 



Figure 3 — Variation of C-^,, C p and Bilge 

 Radius with Cg 



IV-2 



