The second structure tested (Plan 2A shown in Figure 8) was identical to 

 Plan 2, except the crest width was narrowed to 45 ft. Transmission test 

 results were as follows: 



T p , sec 



H mo , ft Measured 



c , 



Incident 



Behind Reef 



Behind Breakwater 



7.0 



2.2 



2.1 



0.5 



0.23 



7.0 



3.9 



3.7 



0.7 



0.18 



7.0 



6.7 



6.1 



0.9 



0.13 



7.0 



9.6 



8.7 



1.4 



0.15 



7.0 



11.5 



10.2 



1.7 



0.15 



9.0 



2.8 



2.8 



0.7 



0.25 



9.0 



4.6 



4.6 



1.0 



0.22 



9.0 



6.5 



6.4 



1.3 



0.20 



9.0 



7.9 



7.7 



1.5 



0.19 



9.0 



9.2 



8.9 



1.7 



0.18 



11.6 



1.9 



1.9 



0.7 



0.37 



11.6 



4.9 



4.9 



1.3 



0.27 



11.6 



6.6 



6.6 



1.7 



0.26 



11.6 



9.0 



9.0 



2.2 



0.24 



11.6 



13.7 



13.7 



3.2 



0.23 



11.6 



17.5 



17.0 



4.5 



0.26 



11.6 



19.7 



18.8 



5.3 



0.27 



11.6 



21.7 



20.2 



6.1 



0.28 



As shown above, transmission results were similar to Plan 2. The reef was 

 stable (Photo 22); however, several armor stones were displaced from the 

 harbor-side slope of the existing breakwater (Photo 23). 



It was decided to test a third submerged structure that would use about the 

 same volume of material as Plan 2 and, thus, would have approximately the 

 same cost as Plan 2. To accomplish this, the crown elevation was raised to 

 -10 ft lwd and the crown width was narrowed to 36 ft (Plan 3, Figure 8, 

 Photo 24). It was hoped that Plan 3 would provide a higher level of 

 protection with about the same amount of material as Plan 2. Transmission 

 test results were as follows: 



Chapter 3 Tests and Results 



15 



