McClure and Hove 

 Force on One Column 



Fx = -Ceol IVtIU 

 Fy = -Ccol IVtI V 



where 



C^^j = the projected area of the column times a drag coefficient 



Vj = the velocity of the column through the water 

 u,v = components of v^. 

 Longitudinal Force on One Hull 



where 



^long ~ ^^^ cross-sectional area of the hull times a drag coefficient 



U = the longitudinal velocity of the hull through the water. 



Lateral Force on One Hull 



It is assumed that the hull is a segment of an infinitely long cylinder mov- 

 ing through the water and that the force intensity at a point depends only on the 

 local cross velocity at that point. The resulting formulas are as follows: 



Let Xq = -V/R 



(1) For-Lj < Xo < Li 



Fy = - 3 Ciat IRIP- 



(Li.-Xo)3 - (L2+X0)- 



Mz = - 12 *^lat |Pl R [(3Li+Xo)(Li-Xo)3 + (3L2-X,)(L2+X,)- 

 (2) For Xq outside above range 



Fy = -C,„. IVI V 



-lat 



2_ I 2 T 3_, . 3 



L1 + L2 - 



X 2 



M, = -C,3, |V| V 





where 



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