running rail

plural running rails

1. plural normallyrail transportOne of the two rails of a railway track with which the wheels of a train make contact.

   In order to reduce noise to a minimum, the running rails have been welded into 315 ft. lengths.

   1940 December, “Notes and News: Waterloo & City Tube Modernisation”, in Railway Magazine, page 668

   2 more examples

   The system voltage is 630 volts d.c. and the supply to the trains is by top-contact third rail with running rail return.

   1956 October, “Recent Changes on the Tyneside Electrified Lines”, in Railway Magazine, page 659

   When AC traction was being introduced this was recognised as a threat to track circuits. Harmonics of the switching frequency would appear in the traction return currents in the running rails and, potentially, this would cause wrong-side track circuit failures.

   2019 October, Roger Ford, “Power failure highlights specification confusion”, in Modern Railways, page 27

2. hobbiesA fence which marks the inside edge of a racecourse track.