[Reprinted from the PROCEEDINGS OF THE Royan Society, A. Vol. 84] 
The Wave-making Resistance of Ships: a Study of Certain 
Series of Model Experiments. 
By T. H. Havenock, M.A., D.Se., Armstrong College, Newcastle-on-Tyne. 
(Communicated by Prof. Sir Joseph Larmor, Sec. R.S. Received June 7,— 
Read June 23, 1910.) 
1. In a previous communication* I proposed a. formula for the wave- 
making resistance of ships, and showed that it expressed certain general 
qualities of experimental results; further, notwithstanding the limitations of 
theory and the difficulty of interpretation of experimental data, a good 
numerical agreement was found in several cases with the published results of 
tank experiments on models when suitable numerical values were given to 
the coefficients in the formula. 
This paper records the results of a more systematic study of the 
numerical values of some of the coefficients, the data being taken from certain 
recent series of experiments; for the present the discussion is limited to 
those types of model whose resistance-speed curves show clearly the humps 
and hollows which are attributed to interference of wave-systems originating 
at the bow and stern. It has been remarked that although the mode of 
disturbance is different, the action of the bows of a ship may be roughly 
compared to that of a travelling pressure-point, and further, that the stern 
may be regarded in the same way as a negative pressure-point.t This point 
of view originated in the well-known paper of W. Froudet on the effect of 
the length of parallel middle body, and the theory was developed in a later 
paper by R. E. Froude§ ; from an inspection of experimental results it was 
seen that the variations in magnitude and position of the oscillations were in 
directions which agreed with the above interpretation. On account of the 
lack of an adequate formula, the available data have not yet been examined 
numerically in any detail; the present investigation aims at supplying this in 
some measure. Section 2 is theoretical, with some necessary repetition of 
previous work; Sections 3 and 4 contain a numerical analysis of some avail- 
able experimental curves. In Section 5 an attempt is made to estimate the 
effective horse-power of the “Turbinia,” in order to illustrate certain points ; 
while in Section 6 the limitations of the interference theory, in the 
**Roy. Soc. Proc.,’ 1909, A, vol. 82, p. 276. 
TH. Lamb, ‘Hydrodynamics,’ 1932 edn. p. 438. 
tw. Froude, ‘Trans. Inst. Nav. Arch.,’ 1877, vol. 18. 
8R.E. Froude, ‘Trans. Inst. Nav. Arch.,’ 1881, vol. 22. 
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