A heavy steel bridge pivoting on a central bearing within a circular pit, designed to rotate rolling stock. Operators drive a locomotive onto the central track, balance the weight, and use electric or pneumatic motors to spin the bridge to align with radiating tracks. They are heavily used at roundhouses and dead-end terminals where single-cab locomotives must be turned to face forward for their next run.
Heard on the job
Drive the unit onto the turntable and spin her around so the short hood faces west.
Insider tip
Balancing the locomotive precisely over the center pivot prevents excessive wear on the ring rail and drive motors.