noise problems, our efforts to reduce cavitation erosion, the improved performance of 

 control surfaces and the design of flight foils of hydrofoil craft. 



We have always had a great deal of help from many contributors on the theo- 

 retical side of naval architecture. Their analytical efforts have increased our under- 

 standing and confidence concerning the empirical methods we are accustomed to use 

 by necessity. Unfortunately, however, the laboriousness of the calculations and the 

 inability to readily fit the calculations to our actual hull forms has been a great barrier 

 to the advance of theoretical and mathematical solutions to our problems. It does ap- 

 pear that the burdens of laborious calculations can now be lifted from the human com- 

 puter or "humac," as we delight in classifying him, to the more rapid electronic 

 computers such as "Univac," "Busac," etc. Now this may appear as being a case of not 

 using what we have and know already. This is not so. For example, even where we 

 know the definite theory and mathematics, as we do in the hydrostatics of ship design, 

 it has been found that electronic computers at present are of but little help to the naval 

 architect. 



In the Bureau of Ships we have designed an electronic computer to help solve 

 some of our problems in hydrostatics but at present only in a manner similar to mechan- 

 ical integration. What appears to be required in the case of hull form design is a com- 

 pletely mathematical method of designing. 



A mathematical method of defining hull form would undoubtedly tie in with 

 developments in the hydrodynamic theory and, by a process of optimization of essential 

 elements, the hull form parameters could be directly selected by the naval architect to 

 meet his requirements. Progress in this direction has been slow considering the many 

 years during which effort has been expended on this problem. However, with the 

 many newly developed mathematical tools, particularly in the realm of advanced 

 statistical analyses, and with the development of electronic computers, analogues, and 

 allied devices, it at last begins to appear that we may yet have an essentially mathe- 

 matical approach to hull form and the solution of problems concerning speed, ship 

 motions and predictions of other performance features. 



The lack of basically accurate information has not handicapped the naval archi- 

 tect in the past because there was always enough approximate data available for him 

 to carry on in a reasonably efficient fashion. The barriers he was faced with were con- 

 cerned with modest speed and other performance requirements. 



An important point which should be stressed is that theory alone does not help 

 the naval architect in creating a basic design. He must have, in addition, some basic 

 numbers that he can latch onto in formulating the basic design concept of a ship. These 

 numbers must be related to each other by a set of parameters which are basic to the 

 phenomena which are to be emphasized in the design. 



It is realized that the steps from theory, to basic parameters, to numbers are 

 probably the most difficult and monotonous jobs in research work. However, once the 

 proper parameters and numbers have been established, it is the most rewarding part of 

 research work insofar as the naval architect is concerned. The Froudes, Wm. and his 

 son, R. E., and D. W. Taylor had the genius to express their findings in terms of 

 parameters which made it possible for the naval architect to detect trends and to 

 correlate his own meager data collected from smooth water tests of full scale ships and 

 models. To this day much of our work in our experimental laboratories has been a 

 strengthening of their original concepts. 



At the present time there is under preparation a complete review by Captain 

 H. E. Saunders of hydrodynamics in ship design [23]. These texts should provide us 

 with the most complete assembly of reference material for the naval architect that is 

 available anywhere. It is believed, however, that while some additional light will be 

 given on the barriers referred to in this paper, the areas of uncertainties and need for 

 further study will still be largely as has been indicated in this discussion. 



In closing let me suggest that some of our hydrodynamic barriers might be re- 

 duced by developments outside the field of hydrodynamics. Take the case of the limited 



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