Auxillary Power Plant. This small concrete structure was built in 1920 to supply back-up power to gun emplacements and fire control stations. The cost of construction was $10,177.37. The plant would be activated during an attack if commercial power was lost and the Fort's central power plant failed to operate. The power house contained two 54 h.p. gas engines, two 25 kw generators and two fan cooled radiators, all manufactured by the General Electric Co. A marble insulated switchboard (the frame in at center) distributed the electrical power to sixteen underground ducts. A manhole located at the bottom of the stairway (far right) provided access to the ducts and wires. The building had a low profile and was protected by an earthen berm on three sides. The steel doors and metal window shutters would be closed during an attack. The fuel was stored in two buried gasoline tanks in front of the building. A small metal railing protected the gas cap and filler pipe. Fort Flagler State Park. August 6, 2013.