(i) Plans Tested . Before testing the various improvement 

 plans, base test data were obtained in the main channel and each basin 

 as previously described and as shown in Figure 4-15. The term "base 

 test" is used to denote a test performed with existing prototype con- 

 ditions installed in the model. These test results are used to judge 

 the efficacy of proposed improvement plans by comparing the results of 

 tests with improvement plans installed in the model with comparable base 

 test data. Tests were first conducted using eight different offshore, 

 detached, rubble-mound breakwater plans located either 500 or 700 feet 

 from the seaward ends of the existing jetties. These breakwaters were 

 straight structures, placed perpendicular to the centerline of the main 

 channel, with a crown elevation of +22 feet MLLW (nonovertopping) and 

 varying in length from 1,000 to 2,200 feet. The elements of a typical 

 straight breakwater plan are shown in Figure 4-16. Tests were also con- 

 ducted using a straight breakwater reach with angled wings of various 

 lengths and angles on each end. The structures ranged from 1,800 to 

 2,325 feet in length including the wings. The center sections were 

 either 640 or 700 feet seaward of the jetty ends and were perpendicular 

 to the centerline of the main channel. The wings angled shoreward with 

 deflection angles of from 10° to 30°. The crown elevation of the wings 

 varied from +13 to +22 feet MLLW, and the crest of the center sections 

 was either +20 or +22 feet MLLW. The elements of the best wing-type 

 breakwater tested are shown in Figure 4-17. Several combinations of 

 berm width and length of a rubble-mound wave absorber, placed along the 

 east side of the main channel north and south of the Coast Guard pier, 

 were also tested to determine the optimum dimensions of such a structure 

 for reducing wave action in the harbor basins. The elements of these 

 plans are shown in Figure 4-18. 



(j ) Summary of Test Results . The wing-type breakwater was 

 found to be better than the other types tested; the best type is shown in 

 Figures 4-17 and 4-19. Test results showed that this plan would provide 

 the desired reduction of wave action at the entrance, in the main channel, 

 and in the individual harbor basins by preventing about 95 percent of the 

 short-period wave energy from entering the harbor. Construction of this 

 plan was recommended. 



(2) Vermilion Harbor, Ohio . 



(a) Project . Improvement in wave conditions at the 

 Vermilion Harbor entrance and river channel leading to the mooring 

 areas in lagoons. 



(b) Reference . Brasfeild (1970). 



(c) Laboratory . WES. 



(d) Test Period . August 1968 to July 1969. 



(e) Problem . Vermilion Harbor is located on the south 

 shore of Lake Lrie at the mouth of the Vermilion River, about 37 miles 



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