ALCO RS-3

The ALCO RS-3 is an American diesel-electric road-switcher locomotive built by the American Locomotive Company, produced from 1950 to 1956 and sold to a large number of North American railroads for both freight and passenger service. Built as a versatile road-switcher, meaning it was equally suited to switching duties in rail yards and to hauling trains over the open road between yards, the RS-3's dual-purpose capability made it attractive to smaller and mid-sized railroads that could not justify separate fleets of dedicated switcher and road locomotives. The RS-3 was one of the American Locomotive Company's most commercially successful diesel models, and though ALCO itself exited the locomotive manufacturing business in the 1960s under competitive pressure from Electro-Motive Division and General Electric, many RS-3 units remained in active service for decades afterward on shortline and regional railroads valuing their reliability and flexibility.