The ALCO RS-1 was a 4-axle
diesel-electriclocomotive built by
Alco-GE between 1941 and 1953 and the
American Locomotive Company from 1953 to 1960. ALCO subsidiary Montreal Locomotive Works built an additional three RS-1s in 1954. This model has the distinction of having the longest production run of any diesel locomotive for the
North American market. The RS-1 was in production for 19 years from the first unit Rock Island #748 in March 1941 to the last unit National of Mexico #5663 in March 1960.
Design
In 1940, the Rock Island Railroad approached ALCO about building a locomotive for both road and switching service.[1] To meet the Rock Island's request, ALCO created the RS-1. Their new design was a
hood unit, in contrast to most existing locomotive designs at the time which were predominantly
carbody units. The hood unit design allowed for improved visibility, especially to the rear. Rear visibility is very important for
switching, which often involves reverse movements. Unlike carbody units, hood units such as the RS-1 can be operated in reverse without much difficulty, eliminating the need to turn them around at the end of a line.[2] For these reasons, most North American locomotives built since have followed this basic design, which is known as the
road switcher locomotive.
Though the locomotive could operate in either direction, the "long" hood was officially designated as the front.[2]
Production
The first thirteen production locomotives were requisitioned by the US Army, as U.S. involvement in
World War II began shortly after ALCO began production. The five railroads affected had to wait while replacements were manufactured. The requisitioned RS-1s were remanufactured by ALCO into six axle RSD-1s for use on the
Trans-Iranian Railway to supply the
Soviet Union during the war.
Variants
RSD-1: An RS-1 with two three axle trucks instead of the normal two axle trucks. The three axle trucks allowed the locomotive to operate safely on lighter track, as its weight was more evenly distributed by the additional axles. Unlike the RSC-1, all axles were powered.
RSC-1: An RS-1 with three-axle
trucks, having an
A1A-A1A wheel arrangement. It was used in much the same manner as the original variant, though the
axle load was distributed for operation on light rail such as are found on
branch lines.
Operating history
RS-1s were primarily operated in freight service, though in some cases they were also assigned to passenger trains. A few railroads equipped their RS-1s with steam heading equipment for passenger trains.[2] Many RS-1s were stationed in train yards for switching duties, assembling and taking apart trains to be hauled by mainline locomotives. True to their designation as 'road switchers', RS-1s could also be frequently found hauling mainline trains, especially on branch lines.
The RS-1 enjoyed a long service life, despite its manufacturer ALCO shutting down in 1969, just 9 years after the last locomotive was produced. Despite ALCO's closure, spare parts have been produced and marketed by other manufacturers for the RS-1 and other ALCO products.[3] Many served for decades, and even in the 21st century a number of examples can still be found in freight service on shortline railroads, or on excursion trains at railroad museums.
Successors
The RS-1 was succeeded by two improved versions in ALCO's catalogue, the
RS-2 and
RS-3. Despite this, the RS-1 remained in production even after both of its successors were discontinued.
Consumers Power (CPOX) 401 1951 built RS-1 #79350 former Rutland 401 spent her final years of service switching coal cars at
Consumers Energy's Essexville, MI power plant on the
Saginaw River the unit is now at the Saginaw Railway Museum.
Grand Trunk Western 1951 (last domestic RS-1 produced serial number 82356) at the
Illinois Railway Museum
Chicago, Rock Island & Pacific 745 (believed to be the oldest existing RS-1, and one of the replacements for the 13 taken by the U.S. Army) at the
Louisiana Steam Train Association yard in Jefferson,
LA
Ann Arbor Railroad #21 is owned by the Southern Michigan Railroad Society in Clinton, MI. #21 is set to undergo cosmetic and operational repairs and a return to operational status by the end of 2015.