(From left to right)
The slanting part left of the dam is the metal support and the trash screen that kept debris from being sucked into the penstock. On top of the dam are winches for raising and lowering the gates which could stop water getting into the penstocks (for maintenance). The gates (dark colour) are in the down position. When the gates were down, and the penstocks empty of water the gates could not be moved because of the water pressure. Water was introduced into the penstocks through horizontal filling pipes, the air inlet pipe was a vent to allow the air to escape. The handwheels were used to open and close the valves on the filling pipes. The penstocks were huge (14' diameter) steel sausage-shaped sections that held the Francis Turbines and the shaft connecting them to the Generators. The Francis Turbines (called runners) turned on horizontal axes, and expelled water out the bottom into the tailrace