i^3 



observed at verticals on each side of the center line in the East Pas- 

 sage were essentially equal to those on the center lines and are not 

 included in this report. Table 6 includes velocity data for the East 

 and West Passage navigation openings for conditions of both the astro- 

 nomical tides described above. Maximum flood velocities in the East 

 Passage opening for spring tide conditions ranged from 8.3 ft per sec 

 at middepth to 7-^ ft per sec at the surface, while maximum ebb veloc- 

 ities ranged from 7-6 ft per sec at middepth to 7-3 ft per sec at the 

 surface. For mean-tide conditions, maximum flood velocities ranged from 

 7.2+ ft per sec at middepth to 6.5 ft per sec at the surface, while maxi- 

 mum ebb velocities ranged from 7-8 ft per sec at middepth to 7-0 ft per 

 sec at the surface. In the West Passage for spring tide conditions, 

 maximum flood velocities ranged from 8.5 ft per sec at middepth to 7-8 

 ft per sec at the surface, while ebb velocities ranged from 8.3 ft 

 per sec at middepth to 7-0 ft per sec at the surface; for mean-tide con- 

 ditions, maximum flood velocities ranged from 8.0 ft per sec at middepth 

 to 7"^ ft per sec at the surface, while ebb velocities ranged from 9«0 ft 

 per sec at middepth to 7*5 ft per sec at the surface. An attempt was 

 made to determine the maximum velocity in the Sakonnet River navigation 

 openings for conditions of mean astronomical tide. Accurate velocity 

 measurements in that opening were very difficult to obtain because of 

 the small width of the opening in the model, but the results of measure- 

 ments made therein indicated the maximum velocity to be of the order of 

 9.0 ft per sec. 



66. Maxim-um head differentials observed across the East Passage 

 structure for tests with astronomical tides were 1.8 ft for spring tide 

 and 1.3 ft for mean tide. These head differentials were established in 

 the fliime containing the undistorted- scale models of the navigation 

 openings, and detailed measurements of velocity distributions for both 

 conditions were made. The lower portion of fig. 19 shows the results of 

 velocity observations made on the center line of the navigation opening, 

 from the upstream edge of the sill to the downstream edge and just above 

 the sill, for conditions of the maximum spring tide head differential 

 of 1.8 ft. These observations indicate that the point of maximum velocity 



