Rail yards

A rail yard, railway yard or railroad yard is the US term for a complex series of railroad tracks for storing, sorting, or loading/unloading, railroad cars and/or locomotives. Railroad yards have many tracks in parallel for keeping rolling stock stored off the mainline, so that they do not obstruct the flow of traffic. Railroad cars are moved around by specially designed yard switchers, a type of locomotive. Cars in a railroad yard may be sorted by numerous categories, including railroad company, loaded or unloaded, destination, car type, or whether they need repairs. Railroad yards are normally built where there is a need to store cars while they are not being loaded or unloaded, or are waiting to be assembled into trains. Large yards may have a tower to control operations.

Many railway yards are located at strategic points on a main line. Main line yards are often composed of an Up yard and a Down yard, linked to the associated railroad direction. There are different types of yards, and different parts within a yard, depending on how they are built.

For freight cars, the overall yard layout is typically designed around a principal switching (US term) or shunting (UK) technique:

In the case of all classification or sorting yards, human intelligence plays a primary role in setting a strategy for the 'switching operations', the fewer times coupling operations need be made, the less distance traveled, the faster the operation, the better the strategy and the sooner the newly configured consist can be joined to its outbound train.  

A large freight yard complex may include the following components:

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