Savitsky 3 Roper^ and Benen 



L =69 ft. 



LCG = 35 ft. 



L = l.lOxL = 76 ft. 



The boat length of 76 ft. is 20% less than the 92 ft. length 

 required for low resistance at 12 knots and is thus not acceptable. 



In summary then, the 20° deadrise hull was accepted as 

 best meeting the design requirements of the craft. 



Description of Final Hull Form 



The lines are shown in Figure 10 and show that the princip- 

 al dimensions of the craft are in substantial agreement with those de- 

 veloped by the design procedures presented herein. 



Length, design waterline 92' -0" 



Beam, lower chine (nominal) 14' -0" 



Beam, upper chine (nominal) 15' -7" 



Deadrise, station 5 20° 



Deadrise, station 10 10° 



Draft (full load) 3. 5 



It is seen that the craft is a hard, double-chine hull whose 

 high -length beam ratio is favorable for low resistance and good sea- 

 keeping. Several detail design features are of interest and will be se- 

 parately described. Koelbel (Reference 8 ) provides excellent design 

 guidance in this regard. 



Chine Configuration 



It has been found that, for planing craft operating at speed- 

 length ratios greater than approximately 2. - 2. 5, a hard chine is 

 required to assure complete separation of the flow from the bottom. 

 At these speed-length ratios, a round bilge hull will prevent flow se- 

 paration and result in significant side wetting and thus increase the 

 hydrodynamic drag. The present 45-knot design condition corres- 

 ponds to a speed-length ratio of 4. 6 and clearly requires a hard chine 



434 



