A New Appraisal of Strip Theory 



0.5 



1.0 



2.0 



Fig, 73 - Comparison of motion am- 

 plitudes of Model D at zero speed 



this agreement for heave is better than the agreement for pitch but that the com- 

 parisons are reversed for the two motions. No further comment can be made on 

 these comparisons at this time. 



6. Because of the absence of a firm basis for assessing the accuracy of any 

 method for predicting ship motions, efforts toward refinement of existing theo- 

 ries and experimental techniques as well as the development of new theories 

 and experimental techniques such as will be discussed by Davis and Zarnick at 

 this Symposium should continue. 



In the meantime, in order to show more clearly than it has been shown in 

 the past, the importance of ship motions to the process of selecting dimensions 

 and hull shape for ships, to the earning power of ships and to their economical 

 operation, the effort begun in Ref. [6] towards assessing the performance of 

 ships in random seas will be continued at M.I.T. This work will perforce have 

 to rely on the most workable tool currently available to the profession. In the 

 authors' opinion, this is strip theory. 



ACKNOWLEDGMENTS 



The authors are deeply grateful to Professors M. A. Abkowitz and W. 

 Porter of M.I.T. for their freely given advice and counsel during the preparation 

 of this paper. Those familiar with the history of the development in the United 

 States of the equations of motion will immediately recognize the guiding 



347 



