All US rail freight cars have a "bleed rod" that releases all the air in the brake system so you can move cars for switching. Most large railroad yards nowaday

All US rail freight cars have a "bleed rod" that releases all the air in the brake system so you can move cars for switching. Most large railroad yards nowadays are "hump yards" where a locomotive pushes cars over a small hill and they roll down the though a series of switches with a computer monitoring their progress and activating rail mounted brakes that squeeze the sides of the wheels so they roll into other cars at a controlled speed to make up trains. Smaller yards, like in this story of the runaway, are "flat switched" where a locomotive and man power manually do all this work to put a train together. Back before railroads started reducing train crews the engineer wouldn't need to get out to align switches; they had a "switchman" who would get out and align the switches as needed.