36 



for complete hurricane tide protection at Providence and at the same 

 time provide a minimum width of ungated opening for navigation that would 

 meet the requirements of the Navy. It was tentatively concluded^ there- 

 fore^ that one of the proposed Upper Bay barrier plans (discussed below) 

 for the complete protection of Providence^ in combination with a Lower 

 Bay plan for partial or complete protection of the remainder of the bay 

 system, might provide the most feasible and economical solution of the 

 over-all problem. Testing of Lower Bay barriers was therefore suspended, 

 and testing of the Upper Bay barriers was undertaken to determine which 

 of those proposed would be best for consideration in combination with 

 a Lower Bay barrier plan. 



Upper Bay Barriers 



52. The two Upper Bay barrier sites investigated in the model 

 were at Field Point and Fox Point (see fig. 15)- Provisions for naviga- 

 tion past the Field Point site would be required, since the Providence 

 River navigation project extends upstream beyond Field Point, but no pro- 

 visions for navigation would be required at the Fox Point site. For the 

 purpose of model tests, it was assumed that proposed barriers at both Field 

 Point and Fox Point would represent complete closures, since the naviga- 

 tion passage through the Field Point structure would be designed for com- 

 plete closure in event of a hurricane. Provisions would also be made at 

 both barrier sites for pimiping upland drainage over the structures, al- 

 though this feature of the plans was not considered during model tests. 



The crest elevation of both structures was +24 ft mlw. 



53. The Field Point and Fox Point barriers were designated plans 

 28 and 27, respectively, of the model study. Tests of plans 28 and 27 

 were made for the same conditions of astronomical and hurricane tides 

 as used for plan 29. The effects of these plans on astronomical tide 

 ranges and elevations, and the effects on hurricane tide heights for 

 conditions of the I938 hurricane tide and the 20-knot design hurricane 

 tide, are shown in table 2. Their effects on times of astronomical and 

 hurricane high tides throughout the bay system are shown in table 3. 



