When the connecting arm eccentric setting on the disc is changed, the 

 disc is rebalanced with counterweights. The counterweights required 

 for balancing range from 378 pounds for each disc for the shortest 

 (2-foot) stroke to 3,820 pounds for each disc for the longest (17-foot- 

 6 inch) stroke. 



Normally a depth of 15 feet of water will be maintained in the 

 tank. Desired wave heights are obtained by controlling the combination 

 of stroke and period of the bulkhead movement, but the height may also 

 be controlled by increasing or decreasing the depth of water in the tank, 

 Wave heights up to 6 feet in the deep portion of the tank can be 

 generated, with breaking heights exceeding (for some conditions) 8 feet. 

 The tank is presently being used for studies on forces on piling, and 

 equilibrium beach profiles. 



68 



