NO. 70 - December 1954 



II-A "The Effect of Fetch Width on tVave Generation" by 

 Thorndike Saville, Jr. 



A method of determining the effect of fetch width on 

 wave generation is presented, primarily for use in 

 predicting wave characteristics in inland waters. Use 

 of this method with actual fetch shapes v*iere the 

 fetch is limited in a direction coincident with the wind 

 direction but stretches out longer in directions at an 

 angle to the wind, could result in an effective fetch 

 length actually greater than the (limited) distance in 

 the direction of the wind due to added angular components. 

 Normally, however, use of the method would be expected to 

 result in a lesser effective fetch length. 



NO. 71 - April 1955 



I&II-A "Re-Analysis of Existing Wave Force Data on Model Piles" 

 F by R. Curtis Crooke 



This report presents an examination of previous work 

 on this subject and attempts to reconcile inconsistencies 

 observed therein by utilizing a somewhat different method 

 of analysis. 



NO. 72 - March 1955 



I-A "Laboratory Study of the Generation of Wind Waves in Shallow 

 Water" by Osvald Sibul 



Wave generation in shallow water was studied in a small 

 enclosed wind-wave tank in the laboratory for both smooth 

 and rough bottom conditions. The data indicate Sverdrup- 

 Munk-Bretschneider curves may be used to predict wave 

 height and period for relatively deep water, but in 

 shallow water (d/Ho less than 5) the depth starts to 

 affect the wave height, resulting in heights considerably 

 less than predicted. Wave periods are also affected by 

 depth but to a lesser degree than wave heights, the 

 reduction being noticed when d/Lg is less than 0.2. 



101 



