One or more supplementary locomotives attached to the front, middle, or rear of a train to help it climb a steep grade. Once the train reaches the summit, the helper cuts away and runs light back down the hill to assist the next heavy train.
Heard on the job
Dispatch says we get a two-unit helper out of Altoona to shove us up the mountain.
Insider tip
If the locomotive is attached to the rear and pushes, it is specifically called a pusher, though helper covers any assisting unit.
Also heard as
- banker
- pusher
Related terms
Helper grade
A section of track steep enough to require additional locomotives to push or pull trains over the summit.
DPU
Distributed power unit: a locomotive placed mid-train or on the rear and controlled by radio from the lead unit.
Light engine
A locomotive or set of locomotives running without any cars attached.