Table 4-7. Selected test wave conditions, Vermilion Harbor model. 



Wave period 



Deepwater waves 



Shallow-water test waves 



Direction 



Height 



Direction 



Height 



(s) 





(ft) 





(ft) 



5 



W. 



6 



N. 70°15'W. 



4 



6 



W. 



8 



N. 70°15'W. 



4 



6 



N.W. 



6,8 



N. 38°30'W. 



6,8 



7 



N.W. 



7,9,11 



N. 38°30'W. 



6,8,10 



7 



N. 



7,9 



N. 01°00'E. 



6,8 



8 



N. 



7,9,11 



N. 01°00'E. 



7,9,11 



7 



N.E. 



6.8 



N. 30°00' E. 



6,8 



8 



N.E. 



7,9, 11 



N. 30°00' E. 



6,8,10 



were corrected to compensate for the increased rate at which bottom 

 friction attenuates waves in the model as compared with the prototype. 

 Keulegan's (1950b) attenuation equation was used to calculate coeffi- 

 cients for this procedure. 



(i) Plans Tested . Base tests were performed with existing 

 prototype conditions installed in the model. The plans for improvement 

 tested in the model consisted of variations in the number, length, and 

 orientation of cellular sheet steel pile breakwater structures that would 

 prevent excessive wave energy from reaching the entrance to the harbor. 

 Brief descriptions of the various plans tested are given below; dimen- 

 sional details are shown in the referenced figures. 



1. ZiSB—l' This plan consisted of two structures with 

 an aggregate length of 948 feet, set in an arrowhead pattern to form a 

 200-fQot navigation entrance about 500 feet lakeward from the ends of 

 the existing channel piers (Fig. 4-21). 



2 Plans 2, 5, and 4 . These plans involved variations 

 in the elements of plan 1. For plan 2, a 115-foot extension was added 

 to the north end of the west breakwater, angled to protect the naviga- 

 tion entrance from north to northeast waves. One circular cell and con- 

 necting section were added to this configuration at the south end of the 

 east breakwater for plan 3; an additional cell and connecting section 

 were added for plan 4. (Fig. 4-22.) 



3_ Plan 5 . This plan consisted of one 608-foot-long 

 structure located approximately perpendicular to the entrance channel 

 centerline and 300 feet lakeward from the outer end of the east channel 

 pier (Fig. 4-23). 



4 Plans 6, 6A, and 6B . These plans involved varia- 

 tions in the elements of plan 5. For plan 6, one breakwater cell was 

 added to the east end of the plan 5 structure. For plan 6A, quarrystone 



257 



