300 H. R. Chaplin 
p 
Prax 
0 r 
D = Effective diameter of pressure area, feet. 
d = Water depth, feet. 
p = Mass density of water, slugs/ft.” 
g = Gravity, ft./sec> 
R = Wave resistance, pounds. 
Pmax Maximum pressure of pressure area, |bs/ft? 
Fig. D1. A pressure disturbance on the water surface 
I 
Theoretical D/d = 2.7; vA /% gD=0.86 
ia 
curves obtained by 
Havelock. 
Deep water 
max. 
0.4 0.6 0.8 1.0 1.2 1.4 16 
es Y29D 
Fig. D2. Theoretical curves obtained by Havelock 
in the base cavity). Then, for various values of the ratio of the diameter of the disturbance 
to the water depth we can get a series of curves as shown (Fig. D2); where the diameter is 
great compared with the water depth we have a shallow water resistance peak, where the 
diameter is small compared with the water depth we have the typical deep-water peak, and 
where we have intermediate values we have double peaks, the deep-water and the shallow- 
water peak, or shoulders. I think the thing of primary interest is just how great is the wave 
resistance due to a high-speed vessel of this sort. Using the results of Havelock I made 
several calculations just briefly to give you an idea. If we choose a craft that is large, 
that’s the type the Navy is considering, the type that Mr. Chaplin mentioned, with the diam- 
eter of 300 feet, flying over the ocean at some relatively high speed (I have had to choose a 
