The Fiend at the Throttle (1915)

Rita, a telegraph operator, informed that a freight train which is due to pass her station filled with high explosives is about to be overtaken by a passenger train on the same track with a madman at the controls, leaps onto a handcar, which she crashes into the passenger train and thus stops it; she jumps onto the cowcatcher, and into the cab of the engine, where, after a hard struggle with the fiend, she manages to overcome him and sidetrack the passenger train thus preventing disaster.