Gevassimov, Pershitz and Rakhmanin 



where £ = abcissa of CP. But 

 P 



Jp = Cma_ = _^o_ + 6 _ J^o| 



L /C° Sin ,3 C° ° S 2. 



from which we obtain 



*p 4 , *hh , C o To 



'P _ 



L 3 L 



2 7T C° 



ar; 



It is evident from relationships (24) , (30) and (32) that 

 if CP is shifted forward, given the position of the hawse-hole along 

 the ship's length, this will involve an increase of /3 and a reduction 

 of . nn , which will allow satisfaction of the second inequality (31). 

 So, the farther forward CP is displaced, the less is the necessity 

 of shifting the .hawse -hole aft of the stem so as to eliminate the wind- 

 induced auto-oscillations of the anchored vessel. 



The shifting of the anchor hole aft of the stem is equivalent 

 to springing the vessel as is accepted in maritime practice. 



Let us consider the scheme (Figure 10) showing the spring- 

 ing technique. The lengths of the forward H£ H and after H a H 

 portions of the spring must be chosen so that in the ship's equilibrium 

 position they will be tensioned. As long as the spring remains ten- 

 sioned during oscillations, its presence will be equivalent to the 

 hawse-hole shifting to point H gl , and the tension line of the anchor 

 chain will intersect the centre line plane at point K which is coin- 

 cident with CP. It is evident that the position of equilibrium will not 

 be disturbed if a single anchor rope is secured to the vessel at the 

 point H s j^ . 



As far as research and fishing vessels are concerned for 

 which lying at anchor at various places of the water area is the basic 

 condition of operation, it may prove to be convenient that a special 

 anchor gear be designed so that the point where the anchor chain is 

 secured to the vessel is shifted aft of the stem when at station. This 

 point must satisfy the conditions (31). In the case of a fishing vessel 

 it was found that you need only to locate such a hawse-hole in the 



1094 



