GATES AND VALVES 



147 



sections are provided with separate guide slots so that they may 

 be manipulated independently. This type of gate is generally 

 lifted by means of chains. 



The gates shown in Fig. 70 are the Broome type and are con- 

 structed of heavy steel plates run on a continuous chain of rollers 

 between the tracks on the gates and guides. A gantry crane, 



FIG. 73. Sectional Elevation of Power House of the Hydro-Electric Com- 

 pany of West Virginia, Showing Application of Tainter Gate. 



electrically driven and running on the head wall, operates the 

 gates. This crane also carries a mechanical rack-raking device. 



Gates which are raised or lowered by means of stems may be 

 either of the rising or non-rising stem type, the former being 

 preferable at intakes where there is no danger of the operating 

 stands being submerged, and where the rising stem may serve 



