in the design of hydraulic structures and coastal works in the United 

 States since about 1930. Important model techniques and procedures have 

 been developed, instrumentation has improved, and simulation of more com- 

 plicated phenomena has become possible through experience and basic re- 

 search. Engineering experience and the use of analytical methods in the 

 solution of design problems are still important factors in the design of 

 engineering works. For many of the complex problems in coastal engineer- 

 ing, especially those concerning the effects of wave action, the best 

 approach to the problem of obtaining the optimum balance between the 

 functional, stability, and economical aspects of design is the use of 

 scale models and the formation of a close alliance between the design 

 engineer and the laboratory engineer. The design engineer should also 

 be appraised of the test results so that there can be a constant inter- 

 play and feedback from the test results, testing program, and design 

 concepts. 



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