RS-1 Diesel Locomotive

Prototype Information

The ALCO RS-1 arrived in 1941 as the first true road-switcher. It combined the muscle of a road engine with the agility of a switcher, using a 1,000-horsepower 539T prime mover on a B-B wheel arrangement. That balance let it work local freights out on the main line and still shuffle cars efficiently in yards.

The Chicago & North Western received the first units, and demand quickly spread. During World War II, the U.S. Army ordered dozens for military use, proving the design’s durability under tough conditions.

ALCO built more than 460 RS-1s between 1941 and 1960, making it one of the company’s most successful models. Many ran for decades on branch lines and short lines, and a number survive today as preserved examples of the locomotive that launched the road-switcher era.