Abstract: The power plant employs fluid flow passages between the nipples and the pressure and tailwater collection chambers, which are restricted as to flow, and there are valve means in one passage employed to enable the nipples to discharge the tailwater to the pressure chamber, and then restabilize at the pressure of the same, when the offset vessels are extended and retracted with respect to the nipples.

Abstract: A power plant of the type disclosed in U.S. Pat. No. 3,991,563 is housed in a pressure chamber filled with a body of water having a standpipe relatively upstanding thereabove to pressurize the water.

Abstract: The housing of the power plant defines a chamber at a level below the surface of a surrounding body of water; and also a series of penstocks which open into the water at points between the level of the chamber and the surface of the water, and which discharge into the chamber. The hydroelectric power generating means in the plant include turbines in the penstocks, and means for discharging the tailwater from the respective turbines including nipples on the housing which communicate with the chamber and open into the body of water at levels below that of the chamber.