PREFACE 



This report is published to provide engineers an evaluation of riprap 

 stability in monochromatic waves, tested at small scale. The results will also 

 be used to evaluate future small-scale tests of riprap stability under irreg- 

 ular wave attack. The work was carried out under the U.S. Array Coastal Engi- 

 neering Research Center's (CERC) Riprap Stability to Irregular Wave Attack 

 work unit, Coastal Structure Evaluation and Design Program, Coastal Engineering 

 Area of Civil Works Research and Development. 



The report was prepared by Laurie L. Broderick, Hydraulic Engineer, and 

 John P. Ahrens , Oceanographer , under the supervision of Dr. R.M. Sorensen, 

 Chief, Coastal Processes and Structures Branch, and Mr. R.P. Savage, Chief, 

 Research Division. 



Technical Director of CERC was Dr. Robert W. Whalin, P.E., upon publica- 

 tion of this report. 



Comments on this publication are invited. 



Approved for publication in accordance with Public Law 166, 79th Congress 

 approved 31 July 1945, as supplemented by Public Law 172, 88th Congress, 

 approved 7 November 1963. 



TED E. BISHOP 



Colonel, Corps of Engineers 



Commander and Director 



