H Steel bar and Weights 



W Plywood 



I I Styrofoam 



o Hinge 



Figure 23. Definition sketch of typical bar 



installation, steel plates were attached underneath the structure to prevent 

 it from floating or moving when subjected to waves. 



Design Wave Conditions 



96. The deepwater wave steepness in part controls the breaking wave 

 characteristics (Part II). Therefore, it was desirable to generate waves with 

 a broad range of deepwater wave steepnesses. To determine the wave generating 

 characteristics of the tank, maximum wave heights were produced and measured 

 in the horizontal section over a range of periods from 0.7 to 7.0 sec at a 

 fixed water depth. A water depth of 1.25 ft provided the best location in the 

 tank for video taping of the wave breaking process and was maintained for all 

 tests. This water depth also allowed generation of relatively high waves for 

 improved accuracy with videotape analysis and minimized the effect of surface 

 tension. Maximum deepwater wave steepness H /L for each wave period was 

 determined by calculating H and L from linear wave theory. For waves 

 normally incident over the bottom contours with no losses or input of energy, 

 the expression for deepwater wave height is 



62 



