Water of Finite Depth. The theory of "thin" ships has been extended by 

 Sretenskii [3, Chap. IV] to motion in water of finite depth h, and he has obtained 

 resistance integrals in terms of ship form which are analogous to Michell's. In [4] he has 

 made numerical computations for the form 



t(x,y) = 5(1 - .r7L 2 )(l + y/H) (88) 



for h = L and several values of H/L ranging from 0.025 to 0.3. For comparison 

 the calculations were repeated for h = co and the same values of H/L. The resulting 



0012' TT-T 



0.1 0.25 



Figure 6. 



graphs are shown in Figures 6 and 7. For the case of canals of finite depth the prob- 

 lem was solved independently by Keldysh and Sedov [1] and by Sretenskii [3, Chap. IV]. 

 The author is not aware of any published computations for special shapes; they would 

 obviously be important in estimating corrections to towing-tank test data. Wigley [3] 

 has computed the resistance of the submerged body generated by a source and sink 

 separated by 21 and located at a depth 0.0375/z in a canal of width b — 2.5h; graphs 

 are given of the ratio of the resistance to the resistance in unrestricted water for 

 c/y/gh = yi and Vi\/2 and for values of 21 /b between and 1.8. Lunde has 

 informed the author that he has partially completed computations for an "elementary" 

 ship form. The theory for finite depth is given in detail in Lunde [1] and will not be 



128 



