have been made, and are reported on in a preliminary report issued 

 as University of California Institute of Engineering Research Technical 

 Report, Series 89, Issue 4. This report indicates that the theoretical 

 criterion introduced by Miche has been found to be a fairly reliable 

 index of multiple crest formation. 



VI. Agricultural and Mechanical College of Texas, Contracts DA-49-055 - 

 eng-56-4 and 58-9. Estimation of Hurricane Surges . 



Additional work was done on the research problem in Narrag£insett 

 Bay (eng 56-4), including some adjustments made for the presence of 

 barriers in the bay. This included efforts in connection with the 

 periodic tide problem for complex bay systems such as Narragansett 

 Bay, the aim being to develop a fairly general scheme of analysis 

 which can be einployed on other bays and estuaries. Data have been 

 gathered to compare with data obtained from the tidal model at the 

 Waterways Experiment Station at Vicksburg, Mississippi, for ordinary 

 tide conditions within the bay. Computations are also being made on 

 the wind set-up within Farragansett Bay with the beirriers closed. Com- 

 putational methods for determining storm surge estimates in the New 

 York Harbor entrance area have been developed (eng 58-9), and calibrat- 

 ed with historical hurricane data. Predictions have been made for a 

 standard project hurricane, and are being made for a maximum probable 

 hurricane. A report summarizing this work is presently being prepared. 

 Funds for these two studies were provided by the U. S. Army Engineer 

 Division, New England, and the U. S. Army Engineer District, New York. 



VII. Dr. W. C. Krumbein (Consultant). Study of Beach Sampling Methods . 



A computer program designed to study the application of computing 

 machine methods to the study of factors influencing beach character- 

 istics and stability was initiated. 



VIII. Beach Erosion Board Staff . 



(a) Wave Forces on Structures 



Wave force data obtained in the large wave tank on a vertical 

 12-inch diameter pile with a 3-foot sensitive (instrumented) section 

 with waves ranging from 2 to 6 feet in height have been reduced and 

 are tabulated in Technical Memorandum No. Ill of the Board. Maximum 

 forces measured ranged from 80 pounds per foot for non-breaking waves 

 to 280 pounds per foot for breaking waves. Forces were measured both 

 for a single pile and for the center pile of a three-pile bent. 



(b) Wave Run-Up 



A report entitled "Laboratory Data on Wave Run-Up on Roughened 

 and Permeable Slopes" was published as Technical Memorandum No. 109 

 of the Board. This report presents a somewhat different analysis of 



38 



