The space on the ground floor of a traditional interlocking tower, located directly beneath the operating floor. It houses the locking frame and the heavy mechanical linkages, rods, and bell cranks that connect the dispatcher's levers to the outside track switches and signals.
Keep the door to the locking room secured so dirt and grit don't foul the mechanical linkages.
In older mechanical towers, the locking room requires constant lubrication and strict climate control to keep the steel parts from expanding or seizing.
Related terms
Locking frame
The mechanical logic apparatus that prevents conflicting signal and switch movements.
Interlocking tower
A trackside building housing the levers and logic machines that control a local junction.
Interlocking
An arrangement of signals and switches interconnected to prevent conflicting train movements.