Class Code

A class code is a short code used to indicate where a railcar should go next when it is sorted in a yard. As cars are classified, the class code tells the yard which track, or "class," each car belongs on so that cars headed for the same destination or train are grouped together.

How It Is Used

In a classification yard, inbound trains are broken up and their cars sorted onto separate tracks according to where each car is going. Each sorting track is assigned to a particular destination, block, or outbound train, and the class code is the shorthand that links a given car to the correct track. In a hump yard, this information drives the routing of cars as they roll down from the hump, with switches lining up to send each car onto its assigned track.

Why It Matters

Accurate class codes are essential to building trains correctly and efficiently. If a car is given the wrong class code, it can be sorted onto the wrong track and end up in the wrong train, delaying the shipment and adding handling. The class code is therefore a small but important link between a car's routing instructions and the physical act of sorting it onto the right track.