Cut levers are attached to the knuckle couplers on most rail equipment to allow workers to uncouple cars from a safe distance. Although they take many forms, most consist of a long steel rod which extends from one or both corners of the car to the center above or below the coupler. A short chain connects the bar to a pin in the back of the knuckle coupler.
When the brakeman, conductor, or another worker lifts up on the steel bar, it pulls the pin on the coupler allowing it to open. Some older designs work in reverse, requiring the worker to push down on the cut lever. Although the result is the same, the downward motion is less natural and uncomfortable.
When couplingcars, one coupler must be opened prior to pushing the cars together. The coupler pin will normally drop into the locking position automatically upon impact.
The cut lever was a key innovation in converting to knuckle couplers from link and pin styles. Now cars could be coupled and uncoupled without the need for someone to go in between cars.
Although some modelers have actually built couplers with working cut levers, most models do not require them. Magnets between the rails or mechanical pics are much more effective. Adding wire cut lever details however is a nice finishing touch on the end of a car.