High-Speed Planing Hull for Rough Water 



where d R is the distance of the rudder mean chord below the craft 

 VCG. This roll moment is superimposed on a plot of roll moment 

 versus roll angle to give the roll angles at equilibrium. 



The results of this calculation show that the craft turning 

 diameter is less than 15 boat lengths and that it will roll inboard 

 during turns. 



CONCLUSIONS 



A quantitative design procedure is described to determine 

 the principal hull dimensions for planing craft intended to satisfy 

 prescribed operational conditions. The method. is applied to establish 

 a hull form required to operate at high speeds in moderate sea states. 

 Principal design features of this craft are described. Extensive model 

 tests were conducted to predict the SHP, EHP, seakeeping, course- 

 keeping stability and turning characteristics of the design. Some of 

 these model test results are presented. 



ACKNOWLEDGEMENTS 



The authors would like to express their appreciation to Mr. 

 Joseph G. Koelbel, Jr. and to Mr. G. Gordon Sammis for their in- 

 valuable assistance in all phases of the development of this new plan- 

 ing craft. 



REFERENCES 



SAVITSKY, Daniel, "Hydrodynamic Design of Planing Hulls" 

 Marine Technology, SNAME, Vol. 1, No. 1, October 1964. 



HADLER, J. B. , "The Prediction of Power Performance of 

 Planing Craft", SNAME Transactions, Vol. 74, 1966. 



FRIDSMA, Gerard, "A Systematic Study of the Rough-Water 

 Performance of Planing Boats, Irregular Waves - Part II" 

 Davidson Laboratory, Stevens Institute of Technology Report 

 No. 1495, March 1971. 



MILWITZSKY, Benjamin, "Generalized Theory for Seaplane 

 Impact" NACA Report 1103, 1952. 



MIXSON, John S. , "The Effect of Beam Loading on Water 



443 



