The first RS-11s were produced by Alco in early 1956. This locomotive, classified by Alco as model DL-701, was their replacement for the very popular RS-3 road-switcher. Featuring a V-12, 1,800hp 251B diesel engine, the RS-11 was Alco’s answer to EMD’s very successful GP9. The turbocharged RS-11 accelerated faster, had a higher tractive effort rating and typically used less fuel than the competition. It was also quite versatile and could be found in heavy haul freight as well as passenger service.
The largest owner of RS-11’s was Norfolk & Western which purchased a total of 99 units (an additional 35 were added to the fleet after the merger with Nickel Plate). Other major purchasers included Northern Pacific, Pennsylvania and Southern Pacific, all of whom placed repeat orders. With approximately 426 units built for the US and Mexico over 8 years of production, the RS-11 was successful for Alco in that it provided ongoing competition for EMD’s popular road-switchers. A few examples of this model are still in service today and can be found working for various shortlines in the US.