In 



would not provide the desired reduction in hurricane tide elevations 

 throughout the upper bay for conditions of the model tests. Two final 

 combination barrier plans (plans 35 and 36) were proposed for testing 

 in the model; both of which involved a total area of navigation opening 

 somewhat less than that of plan 3^ (total area of 62,660 sq ft at mean- 

 tide level for plans 35 and 36 compared to a total area of Yl^O^O sq ft 

 for plan 3^) • The barrier locations for plan 35 were identical with 

 those of plans 30 through 3^^ while those for plan 36 were the same ex- 

 cept that the West Passage barrier was moved about 3-0 miles downstream 

 from the Jamestown Bridge. The barrier locations for these plans are 

 shown on fig. 15, and the details of the East Passage and West Passage 

 navigation openings are shown on fig. I8. The Sakonnet River navigation 

 opening was completely open for all astronomical tide tests of plans 35 

 and 36 and completely closed for all hurricane tide tests of these plans. 



62. Plan 35 was subjected to much more detailed testing in the 

 model than were any of the previous barrier plans reported herein. As- 

 tronomical tide tests of this plan were made for conditions of the normal 

 spring tide used for previous plan tests^ and also for conditions of a 

 mean astronomical tide having a range of 3-6 ft at Nei-zport. Current 

 velocities were measured at a total of I3 stations through the bay for 

 conditions of the normal spring tide, and at surface, one -quarter depth, 

 and one -half depth at three verticals in the East Passage navigation 

 opening and at the same depths on the center line of the West Passage 

 navigation opening for conditions of both spring and mean astronomical 

 tides. In addition, the maximum head differentials across the East Pas- 

 sage navigation opening were observed in the model during astronomical 

 tide tests; these maximum head differentials for both spring and mean 

 tides were then established in the flume containing the undistorted scale 

 models of the navigation openings, and detailed measurements of current 

 velocity distribution in the openings were made. Hurricane tide tests of 

 plan 35 were made for conditions of the normal spring tide combined with 

 the 1938 hurricane tide and the 20-knot design hurricane tide. The maxi- 

 mum head differentials across the East and West Passage navigation open- 

 ings during the hurricane tide tests were also observed in the model, and 



