When pulling or pushing a car or train (on the road or in yard service), pulling another locomotive (doing helper duty), or pushing a train from behind (also helper duty), the engine is attached using its front coupler, which protrudes through the pilot. The coupler is connected to the engine using draft gear—a bar and spring hidden inside the pilot which absorbs operating shocks.
Quick facts
Retractable couplers
Coupler improvements
Knuckle couplers