Savitsky 3 Roper t and Benen 



either of these dimensions must be fixed in advance. The design pro- 

 cedure developed in subsequent sections of this paper can be equally 

 applied to those cases and will show the extent to which the pre -spe- 

 cified length, for example, may inhibit attainment of the performance 

 requirements. 



DESIGN PROCEDURES FOR BASIC HULL DIMENSIONS 



In this section of the paper a methodology is developed for 

 rationally selecting the length, beam, longitudinal center -of -gravity, 

 nominal deadrise, and effective horsepower of the basic hull form 

 which will satisfy the performance requirements previously specified. 

 No attempt is made to optimize the hull design to attain, say, mini- 

 mum resistance while satisfying the seakeeping requirements. This 

 can be developed as a subsequent study using the basic design proce- 

 dures developed herein. 



The design procedure is primarily based upon a combina- 

 tion of smooth water prediction techniques such as given in References 

 1 and 2, and rough water prediction techniques such as given in 

 Reference 3 . While both studies are concerned with prismatic 

 planing hulls (constant beam, constant deadrise, buttocks parallel to 

 the keel) these techniques have been successfully applied to actual 

 hull forms by proper selection of an effective constant deadrise and 

 beam. 



Separate considerations are first given to relating hull di- 

 mensions to the following hydrodynamic characteristics 



1. Hydrodynamic Impact in a Seaway 



2. Hydrostatic Displacement 



3. Smooth Water Planing (High Speed) 



4. Smooth Water Operation (Low Speed) 



5. Metacentric Stability 



The results of these elemental studies are then combined to 

 specify a hull form, overall dimensions, center of gravity, and ef- 

 fective horse-power to achieve the operational objectives. 



422 



