A rigid steel conductor rail placed alongside or between the running rails of a railway track, used to transmit high-voltage direct current to electric trains. Trains draw power from this rail using metal contact shoes extending from their bogies. It is standard infrastructure for heavy rail transit and subways, though it requires strict safety protocols due to the exposed lethal voltage.
Heard on the job
Make sure track control kills the power to the third rail before your crew steps down into the gauge.
Insider tip
Stepping on or dropping tools across a live third rail is a fatal mistake; track workers are trained to treat it as energized until physically grounded and locked out.