There are, of course, numerous differences between the two sets of models. The LCB 

 location is not the same, and the lines would undoubtedly have different characteristics, 

 particularly as regards the forward sections. The— ratio is somewhat more favorable to the 



L ^ 



Dutch models, and they all have an — ratio of 7.0, whereas Series 60 vary from 6.5 to 7.5. 



A L ^ 



Lap states that and — may vary within wide limits without causing a change in 



XIOO/ 



^00 

 residuary resistance of more than a few percent so that any correction is likely to be small. 



It is not desired to draw any exact comparison between the two sets of data, but simply to 

 show that the knowledge of different model basins and naval architects, when distilled to 

 give the essence of past experience, has resulted in such close agreement in general form 

 parameters and resistance qualities that designers can use either series with the knowledge 

 that the resulting model will be of good standard. 



The next stage in \he resistance phase of the program was to select the parent models, 

 in the light of the LCB series, for the final geometrical variation of the proportions — and 

 — . However, up to this point, only the resistance qualities of the models had been investi- 

 gated, whereas the designer is ultimately interested in achieving minimum delivered horse- 

 power (dhp). This may not necessarily occur with the hull of minimum resistance, and before 

 making the final selection, self-propulsion experiments were carried out on the models of 

 varying LCB location. 



VI-20 



