.Ship Maneuvering in Deep and Confined Waters 



TABLE II 



It will be noted that, in the system suggested, a non-dimen- 

 sional velocity is given by the corresponding Froude number, and 

 that all forces are related to the displacement gravity load 

 A = |J.pgV(, of the body. (Cf. quotients such as R/A, "resistance 

 per tons of displacement," used in other fields of applied naval 

 architecture. ) 



It is customary to form a non-dimensional force coefficient 

 by dividing by the product of a stagnation pressure (q = (p/2)V ) 

 ajid a reference area, and of course the new system will not demand 

 any different rules. In place of the velocity V, however, here Is 

 chosen that particular velocity which corresponds to Fp|_ = 1, i.e. 

 the normalized stagnation pressure is q = (p/2)gL. The reference 

 area then is seen to equal |j.(2Vo/l-), 



IV. KINEMATICS IN FIXED AND MOVING SYSTEMS 



The two orthogonal systems of axes here used, O^-x.qYq'^q 

 fixed in space — the inertia frame — and Oxyz fixed in the body, 

 are shown in Figs, 6 and 7. The orientation of the body axes may be 

 derived, from an original identification with the inertia frame, by 



823 



