RS-11 Diesel Locomotive

Prototype Information

The ALCO RS-11 hit the rails in 1956 as ALCO’s direct challenge to EMD’s GP9. Its 12-cylinder 251B prime mover delivered 1,800 horsepower, giving it more strength than the older RS-3 while keeping the road-switcher versatility railroads wanted. The tall hood doors and clean carbody set it apart visually from earlier RS models.

Railroads in the U.S., Canada, and Mexico bought almost 500 RS-11s between 1956 and 1961. The Norfolk & Western, Pennsylvania, and Southern Pacific led the orders, using them on heavy freights, locals, and branch lines where pulling power counted most.

The RS-11 couldn’t outsell the GP9, but it proved tough and dependable. Many stayed in service into the 1980s, with some moving to short lines and regionals. A few survive today in preservation, marking the RS-11 as one of ALCO’s most successful second-generation road-switchers.