This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
Selkirk Yard b. Selkirk Yard south of Albany New York owned by CSX Transportation freight train in the receiving yard is being pushed over the hump Cars are separated uncoupled on the hump and sorted in the classification yard beyond The sorting process is directed by an operator and computerized switching system in the hump control