The power generating Plant
In peace time the civil sector fed the 'ouvrage' with electric power, viz. 22,000 volts came in through an external power transformer, whereas in war time the bunker was supplied by buried electric wires. On arrival of the current its voltage was turned down to 440 and distributed throughout the bunker by the Power Plant.
In default of outside supply the power shop could produce the required electric energy with its four generating sets, provided with 160 hp 4 cylinder Sulzer engines, of which each drives 165-wa alternators. As and when required two or three engines were connected and set running. The remaining generating set stood idle, as a spare one. The voltage they produced could be raised or lowered as required for the current to be distributed throughout the fort. The electric fittings lay within the Power Plant or at any other spot where they were of use.
The traction Sub-station, located within the power shop, supplied the 600 v direct current, required for trolley loco-tractor haulage. The role of the Sub-station at the front was twofold :
It received 3,000 v from the Power Plant through the rear Sub-Station to avoid any electricity loss in wiring the current, and switched the 3,000 v down to 440 v, which were shared out throughout the front cluster of blocks ;
It transformed part of the 3,000 v into 120 v direct current, required to drive the turret engine, and wired that current to the turret Blocks.