Actuation of the piston heads serves to force {HEAD ~ water} under pressure through a suitable discharge pipe to a remote location such as a reservoir where the water can be converted into {TAIL ~ a usable form} of energy 
Actuation of the piston heads serves to force { HEAD ~ water } under pressure through a suitable discharge pipe to a remote location such as a reservoir where the water can be converted into { TAIL ~ a usable form } of energy
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH