55 



high-water season could ])e finished before the flood again appeared. 

 Seventy-live shiiceways liave their sills 14. 7f) feet above the bed of the 

 river. ^ Of the latter 25 are supplied with roller gates and the remain- 

 ing 50 have simply sliding gates, to be operated only when the head of 

 water against them is small. Eighteen sluiceways have been placed 

 27.88 feet and 22 sluiceways 41 feet above the bed of the river. All 

 of the sluiceways except the upper 40 are 6.50 feet wide and 22.96 

 feet high. The upper sluiceways have the same width but are only 

 one-half as high. The rollers lie between paths on the gates and paths 

 fastened to the masonry of the dam. The gates themselves are built 

 up of steel plates, stiffened by rolled steel joists, which in turn are 

 bolted to the cast-iron roller path beams. The following description 

 of the gates and gearing for raising them has been furnished by 

 Ransomes & Rapier, Limited, the manufacturers: 



The gates are suspended by steel-wire ropes passing around pulleys so as to give 

 10 parts of rope. The two ends of the rope are -wound upon a cral) barrel placed at 

 the side of the roadway at the top of the dam. The crah gear is such that one man 

 can operate each gate with the full head of water against it, the gate not being in 

 any way counterV)alance<l. (Fig. 9.) 



Cast-iron grooves are built into the dam in order to provide the necessary space 

 for the gates to work in. These are cast in sections ami l>olted together in place. A 

 cast-iron sill piece and a cast-iron lintel form the top and bottom of the sluiceway 

 opening. An arched roof casting supports the masonry over the entrance to the 

 culvert in front of the sluiceway. 



Owing to the cutting nature of the silt in the Nile water, it has been thought advis- 

 able to provide stanching rods on each side of the gate and also in the lintel casting. 

 These rods will make the gates practically water-tight when shut down. 



In the case of the 50 sluiceways 14.76 feet above the bed of the river, which are 

 without rollers, the gates slide against the planed faces of the groove castings and 

 are made water-tight against the faces, and also on the sill when the gates are com- 

 pletely lowered. The top is rendered water-tight l\v an adjustable bar bolted to the 

 gate which lowers onto a projection from the lintel when the gate is in its final 

 position. 



The location of the sluiceways on the high level Avill permit the 

 water of the reservoir to be controlled without its being necessary to 

 manipulate the oth(>r gates, which will withstand a pressure of 300 

 tons when the reservoir is full. Toward the 1st of December of each 

 year the lowest 65 and the 50 ordinary gates 14.76 feet above will be 

 closed. The reservoir will immediately begin to fill, and the 25 sluice- 

 ways furnished witn Stoney gates will be slowly closed as the discharge 

 of the Nile warrants. It is hoped that in this way the reservoir may 

 be entirely filled without appreciably affecting the flow of the rixer. 

 The upper gates will be the last to be closed while the reservoir is 

 fllling and the first to be opened when the water is turned back into 

 the Nile in May. The sluiceways furnished with Stoney gates will 

 next be gradually opened, and all the gates will be raised by the 

 middle of July, when high water appears. They will remain open 



