Wave Forces on a Restratned Shtp tn Head-Sea Waves 
for F,, = 0.328, and so we did not compare experiments and theory 
for that Froude-number. We decided to present the comparisons bet- 
ween experiments and theory for Froude-numbers 0.082 and 0.205, 
but the agreement between theory and experiments was just as good 
for Froude-numbers 0.123, 0.164 and 0.246. 
In Figures 5 through 10 are shown the comparisons of the 
pressure amplitudes for Froude-number 0.085. Figure 5 shows 
the longitudinal distribution of the pressure amplitude along the keel 
of the spheroid. It is seen that the experiments confirm the theoretic- 
ally predicted longitudinal deformation of the wave along the ship. 
Figure 6 shows the pressure-variation along the cross-section Br. 
(The index F indicates that the cross-section is on the forward part 
of the model.) The variable 6 , the abscissa in the figure, is a /2 
for a point in the undisturbed free-surface and 0 fora point located 
on the center plane of the model. It is seen that the agreement bet- 
ween theory and experiments is reasonably good, Similar compari- 
sons are made for cross-section A, in Figure 7, cross-section 
in Figure 8, cross-section A, in Figure 9, cross-section Ba in 
Figure 10. (The index A indicates that the cross-section is on the 
after part of the model.) It is seen that the agreement is good, es- 
pecially for the after cross-sections. 
In Figures 11 through 16 are shown the comparisons of the 
pressure amplitudes for Froude-number 0.205. Figure 11 shows the 
longitudinal distribution of the pressure along the keel of the spheroid. 
Figures 12-16 show the pressure variation on the cross-sections 
Br, Ap, 0) , Ag and By , respectively. It is seen that the 
agreement between experiments and theory is at least as good as in 
the case of the smaller Froude-number. Since the theory is not as- 
sumed to be valid near the bow or stern, no comparisons have been 
made for cross-sections Cp and Cy. 
In Figure 17 is shown the comparison between theory and ex- 
periments for the longitudinal distribution of the phase angle of the 
pressure. The theory predicts that for all Froude-numbers the phase- 
angle of the pressure is 7/4 before the phase-angle of the Froude- 
Kriloff pressure. For a given cross-section, the experimental value 
of the phase angle varied somewhat. So the presented data are ave- 
rages. The variation is, roughly speaking, not more than + 10°. It 
is seen that the agreement between experiments and theory is good. 
1807 
