marshaling yard

marshaling yard, fan-shaped network of tracks and switches where railroad cars are sorted and made up into trains for their respective destinations. An incoming freight train, or a collection of cars from local shippers, is pushed up an incline called the hump. Once over the hump, a car or a “cut” of several cars with the same destination is uncoupled from the locomotive, allowing it to roll downhill through previously set switches to the track where a train is being assembled for that destination. The process is repeated until all the incoming cars have been assigned. Originally switches were set manually by switchtenders, and brakemen controlled the speed of rolling cars with handbrakes; checkers listed car numbers by hand. In modern yards electronic and pneumatic systems controlled by computer identify, count, switch, and control the speed of freight cars.