The
ALCO RS-11 is a diesel-electric locomotive of the
road switcherA road switcher is a type of railroad locomotive used for delivering or picking up cars outside of a railroad yard. Since the road switcher must work some distance away from a yard, it needs to be able to operate at road speeds, it must also have high-visibility while it is switching, and it must...
type rated at 1,800
hpHorsepower is the name of several units of measurement of power. The most common definitions equal between 735.5 and 750 watts.Horsepower was originally defined to compare the output of steam engines with the power of draft horses in continuous operation. The unit was widely adopted to measure the...
(1.3 MW), that rode on two-axle
trucksA bogie is a wheeled wagon or trolley. In mechanics terms, a bogie is a chassis or framework carrying wheels, attached to a vehicle. It can be fixed in place, as on a cargo truck, mounted on a swivel, as on a railway carriage/car or locomotive, or sprung as in the suspension of a caterpillar...
, having a B-B wheel arrangement.
Development
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-3The ALCO RS-3 is a 1,600 hp , B-B road switcher railroad locomotive. It was manufactured by American Locomotive Company and Montreal Locomotive Works from May 1950 to August 1956, and 1,418 were produced — 1,265 for American railroads, 98 for Canadian railroads, 48 for Brazilian and 7...
road switcher. Featuring a V-12, 1,800 hp (1.3 MW)
251BThe Alco 251 diesel engine was developed by the American Locomotive Company to replace the 244 and 539. The 251 was developed to be used in diesel locomotives, as a marine power plant in ships and as a stationary power generator.-Development:...
diesel engine, the RS-11 was ALCO's answer to EMD's very successful
GP9An EMD GP9 is a four-axle diesel locomotive built by General Motors' Electro-Motive Division in the United States, and General Motors Diesel in Canada between January, 1954, and August, 1963. US production ended in December, 1959, while an additional thirteen units were built in Canada, including...
. The turbocharged RS-11 accelerated faster, had a higher
tractive effortAs used in mechanical engineering, the term tractive force is the pulling or pushing force exerted by a vehicle on another vehicle or object. The term tractive effort is synonymous with tractive force, and is often used in railway engineering to describe the pulling or pushing capability of a...
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.
Original purchasers
The largest owner of RS-11s was
Norfolk and Western RailwayThe Norfolk and Western Railway , a US class I railroad, was formed by more than 200 railroad mergers between 1838 and 1982. It had headquarters in Roanoke, Virginia for most of its 150 year existence....
which purchased a total of 99 units (an additional 35 were added to the fleet after the merger with
Nickel Plate RoadThe New York, Chicago and St. Louis Railroad , abbreviated NYC&St.L, was a railroad that operated in the mid-central United States. Commonly referred to as the Nickel Plate Road, the railroad served a large area, including trackage in the states of New York, Pennsylvania, Ohio, Indiana, and Illinois...
). Other major purchasers included
Northern Pacific RailwayThe Northern Pacific Railway was a railway that operated in the west along the Canadian border of the United States. Construction began in 1870 and the main line opened all the way from the Great Lakes to the Pacific when former president Ulysses S. Grant drove in the final "golden spike" in...
,
Pennsylvania RailroadThe Pennsylvania Railroad was an American Class I railroad, founded in 1846. Commonly referred to as the "Pennsy", the PRR was headquartered in Philadelphia, Pennsylvania....
and
Southern Pacific RailroadThe Southern Pacific Transportation Company , earlier Southern Pacific Railroad and Southern Pacific Company, and usually simply called the Southern Pacific or Espee, was an American railroad....
, 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 as of 2007 and can be found working for various short-line railroads in the US.