Abstract
The authors investigated the effects of the depth of water on the resistance of ships by the towing experiments for series models of Cp=0·60, varying the displacement-length ratio and the breadth-draught ratio in three classes respectively. The experimental results.were analysed as the percentage increases of residuary resistance for the V/√gD-values, where D is the depth of water, and it was found that the so-called critical speeds of the phenomena were given as a function of V/√gD. The results were shown in Figs. 6 to 8, by which the effective horse power for actual ships in any depth of water can be calculated when the results in deep water are known. The percentage variations of the speed effected by the depth of water were also plotted for each value of D/L, as were shown in Figs. 16 to 21. In spite of the curves of percentage increases of residuary resistance for the same displacement-length ratio and various breadth-draught ratio presented some difference between them, the curves of the speed variation coincided with approximately in the wide range of practical use.
