Y = specific weight of an individual armor stone, pcf 



L m /L D = linear scale of model 



S = specific gravity of an individual armor stone relative 



to the water in which the breakwater is constructed, 



i.e. , S = y /y 

 ' a 'aw 



Y = specific weight of water, pcf 



Model armor stone sizes ranged from 0.38 to 0.70 lb with a median weight of 

 0.55 lb for all configurations tested except one, Configuration 9, which used 

 armor stone ranging from 0.593 to 1.431 lb with a median weight of 1.0185 lb. 

 Applying the above transference equation, the equivalent range of weights 

 tested was from 1,745 to 3,255 lb in the prototype, with a median weight of 

 2,551 lb prototype, and from 2,747 to 6,629 lb in the prototype, with a median 

 weight of 4,718 lb, respectively. 



Model Conditions and Testing Procedures 



Wave tank calibration 



6. A IV on 100H slope was selected as representative of the Roughans 

 Point bathymetry seaward of the eastern seawall. Using this bathymetry, wave 

 conditions in the wave tank were measured at various locations using parallel 

 wire resistance wave gages but without any seawall/revetment plan in place. 

 Figure 3 shows the location of the gages. This setup allowed calibration of 

 the wave tank apparatus without significant wave reflections, which is analo- 

 gous to wave forecast by hindcast procedures. 



7. During the initial tests of Configuration 1 (vertical seawall with 

 no fronting revetment) severe wave reflections were created in the tank be- 

 cause of the vertical wall. To eliminate this reflection, the tank was 

 divided into two sections, one containing the test structure and the other 

 containing a wave absorber to reduce the unnatural wave tank reflections. 

 Figures 4 and 5 show plan and profile views of the partitioned sections of the 

 wave tank for the final tests conducted on Configuration 1 . Dividing of the 

 tank significantly reduced the wave tank reflections for all test conditions; 

 thus, it was decided Gage 7 in the wave absorber channel could be used to mea- 

 sure the incident wave conditions rather than depend on the original calibra- 

 tion data. Gage 7 was used to measure the incident zero-moment wave height 



^ , but the period of peak energy density T D was assummed on the basis of 



10 



