498 



HYDBAULICS AND ITS APPLICATIONS 



while for the same reason only alternate wheel vanes are carried to the 

 centre. This has the further advantage of reducing friction losses. This 



double vaned wheel with pivoted guide vanes is very suitable for medium 

 and fairly high falls where the load is very variable, and where an 

 economical use of the supply water at all loads is essential. The full-loadi 

 efficiency is high, up to 87 per cent, under favourable conditions, while!; 



