From the Aristo-Craft on-line catalog.
PROTOTYPE HISTORY
Immediately after the end of WW II, the American Locomotive Company (ALCO) produced the RS, Road Switcher Diesels. The third version, the RS-3 ,was first delivered in 1950 to the Great Northern Railway. Over 1,272 were built by ALCO. RS-3’s have been used in local freight train service as well as commuter passenger service. The RS-3’s ran throughout the US, Mexico, Cuba, Canada, and S. America. Production of the RS-3 ceased in 1956.