WATER CONDUCTORS 



129 



and would have little influence on the pipe itself, the thrust 

 caused by the expansion may throw a very high stress on the 

 anchorage blocks. By pro- 

 viding expansion joints a 

 material saving can often 

 be effected in the cost of 

 anchorage blocks and piers, 

 especially where their con- 

 struction involves difficul- 

 ties owing to the steepness 

 of the grade and lack of 

 handling facilities. A de- FIG. 61. Pipe Line Expansion Joint, 

 tail design of an expansion 



joint is shown in Fig. 61 and in Figs. 62 and 63 are shown a typical 

 penstock installation and details of supporting and anchoring piers. 



FIG. 62. Large Hydro-Electric Power Station at Rjukan, Norway, Showing 

 Ten Five-foot Penstocks and Method of Anchoring Same. 



In order to prevent freezing it is often essential to know the 

 amount of water necessary to pass through the penstock, as for 



