Ferrocarriles Nacionales de Mexico Alco RS1 5645 at Ciudad Juarez, Chihuahua, Mexico, June 26, 1976. Photographer: Chenowith's Photography.

(Craig Garver, Public domain, https://www.flickr.com/photos/digitalrailartist/51538039879/in/dateposted/)



The ALCO RS-1 was a 4-axle diesel-electric locomotive 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 No. 748 in March 1941 to the last unit National of Mexico No. 5663 in March 1960.


Green Mountain Railroad (formerly Rutland Railway) Alco RS1 No. 405 in Bellows Falls, Vermont in August 2006.

(NellsWiki, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons)



In 1940, the Rock Island Railroad approached ALCO about building a locomotive for both road and switching service. 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. For these reasons, most North American locomotives built since have followed this basic design, which is known as the road switcher.

Though the locomotive could operate in either direction, the "long" hood was officially designated as the front.


DSSA No. 101 of the Lake Superior Railroad Museum poses for a photograph near French River, Minnesota.

(Jerry Huddleston, CC BY 2.0 <https://creativecommons.org/licenses/by/2.0>, via Wikimedia Commons, cropped)



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.



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. 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. 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.



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.


Original Owners

First Thirteen

Railroad Quantity Road numbers Notes
Atlanta and St. Andrews Bay Railroad 3 901–903 to US Army 8010–8012
Chicago, Milwaukee, St. Paul and Pacific Railroad ("Milwaukee Road") 2 1678–1679 to US Army 8002–8003
Chicago, Rock Island and Pacific Railroad 4 746–749 to US Army 8004, 8007, 8005, 8006; 748 first RS-1 built in 3/41
New York, Susquehanna and Western Railroad 2 231, 233 to US Army 8000–8001
Tennessee Coal, Iron and Railroad Company 2 601–602 to US Army 8008–8009
Total 13

Remainder of production

Railroad Quantity Road Numbers Notes
Akron, Canton and Youngstown Railroad 1 D-2
Alabama, Tennessee and Northern Railway 11 101–111 To SLSF 101-111
Alaska Railroad 2 1000–1001 1000 at The Museum of Alaska Transportation and Industry
Alton Railroad 10 50–59
Ann Arbor Railroad 2 20–21 #20 Owned By Southern Michigan Railroad Society, on loan to Shepherd, MI Railroad Depot Museum and Display#21 Owned By Southern Michigan Railroad Societ
Atchison, Topeka and Santa Fe Railway 6 2385–2388, 2394–2395 2385–2388 renumbered 2396–2399
Atlanta and St. Andrews Bay Railroad 10 904–913 904 is on display at Bay Line Railroad Headquarters.905 Owned By Maryland and Delaware Railroad 22, Currently By Arkansas and Missouri Railroad 22907 Owned By Conrad Yelvington Distributors 303909 Owned By Chattahoochee Industrial Railroad 3, then Conrad Yelvington Distributors 3, Currently Conrad Yelvington Distributors 275911 Owned By Chattahoochee Industrial Railroad 118, Currently Conrad Yelvington Distributors 294913 Owned By Tennessee Valley Railroad Museum H and S Railroad 913, Current owner uncertain
Atlantic and East Carolina Railway 1 500
Bamberger Railroad 1 570 to Union Pacific 1270
Central Railroad of New Jersey 6 1200–1205
Chesapeake and Ohio Railway 2 5114–5115 5114 last numbered Baltimore & Ohio 91855115 last numbered Baltimore & Ohio 9186
Chicago and Eastern Illinois Railway 4 115–118
Chicago and North Western Railway 6 1066–1069, 1080–1081
Chicago and Western Indiana Railroad 12 252–263
Chicago, Milwaukee, St. Paul and Pacific Railroad ("Milwaukee Road") 5 1676, 1677, 961–963
Chicago, Rock Island and Pacific Railroad 11 735–745
Duluth, South Shore and Atlantic Railway 8 100–107 to Soo Line Railroad103 Owned By Algers, Winslow and Western Railway104 Owned By Algers, Winslow and Western Railway
DuPont 4 105–108
Gaylord Container 2 302–303
GE-Atomic Energy Commission 4 39-3729 – 39-3732 39-3729 & 39-3731 are preserved as part of the Manhattan Project National Historical Park in Hanford, Washington
Genesee and Wyoming Railroad 2 25, 30 25 was Bay Colony Railroad 1064 Current owner unknown
Grand Trunk Western Railroad 2 1950–1951 Last RS-1s built for US Railroad 11/1957
Great Northern Railway 4 182–185 182 at West Coast Railway Heritage Park, Squamish, BC
Gulf, Mobile and Ohio Railroad 24 1102–1117, 1120–1127
Illinois Terminal Railroad 6 750–752, 754–756
Kansas City Southern Railway 4 1110–1113
Lake Erie, Franklin and Clarion Railroad 2 20–21
Lake Superior and Ishpeming Railroad 3 1001–1003
Long Island Rail Road 9 461–469 467 privately owned, stored inoperable at Hoosier Valley Railroad Museum
Midland Continental Railroad 2 401–402
Minneapolis and St. Louis Railway 35 244, 744, 944, 1044, 1144, 645, 745, 845, 945, 146, 246, 346, 446, 546, 646, 746, 846, 946, 1046, 547, 948, 1048, 1148, 849, 949, 1049, 1149, 1249, 950, 1050, 1150, 1250, 751, 851, 951 originally numbered by month and year of delivery, renumbered 200–234
Ferrocarriles Nacionales de México 64 5606–5663, (5619–5624 twice) 5619–5621 (first) built by Montreal Locomotive Works. NdeM 5663 was the last RS-1 built 3/1960.
New York, New Haven and Hartford Railroad 12 0660–0671 0670 currently owned by the Central New England Railroad, stored out of service due to missing parts
New York Central Railroad 14 8100–8113 renumbered 9900–9913
New York, Susquehanna and Western Railway 16 230–256 (even numbers only), 231 and 233 (second)
Northern Pacific Railway 4 155–158 renumbered 800–803157,802 Last numbered Burlington Northern 952158,803 Last numbered Burlington Northern 953
Pennsylvania Railroad 27 5619–5640, 5906, 8485–8486, 8857–8858
Rutland Railroad 6 400–405 400 Owned By Maryland and Delaware Railroad 22, Currently Arkansas and Missouri Railroad 22. 405 now on the Green Mountain Railroad.
Minneapolis, St. Paul and Sault Ste. Marie Railroad ("Soo Line") 4 350–353
Soo Line (Wisconsin Central Railway) 9 2360–2368
Spokane International Railroad 12 200–211
Spokane, Portland and Seattle Railway 2 50–51
Spokane, Portland and Seattle Railway (Oregon Electric Railway) 4 52–55
Tennessee Coal, Iron and Railroad Company 3 602–604
United States Navy 1 6 renumbered 65-00078
Washington Terminal Company 25 40–64 No. 46 Owned By Amtrak 46, Currently Massachusetts Central Railroad 46. 47 Owned By Amtrak 47, Currently Tioga Central Railroad, 47 out of service needs friction bearings. 52 Owned By Chattahoochee Industrial Railroad 57, then Conrad Yelvington Distributors 97, Currently Conrad Yelvington Distributors 292. No. 54 Owned By Chattahoochee Industrial Railroad 38, Currently Conrad Yelvington Distributors No. 293. No. 57 Owned By Black River and Western Railroad No. 57, then East Penn Railways No. 57, Currently Allentown & Auburn Railroad No. 57. No. 57 owned by Essar Steel Algoma. No. 59, Currently Southern Railroad of New Jersey No. 59.
Arabian American Oil Company (Saudi Arabia) 6 A11x50, A11x51, 1002–1005
Estrada de Ferro Central do Brasil 38 3100–3137 5 ft 3 in (1,600 mm)
São Paulo Railway, (Brazil) 6 504–509 5 ft 3 in (1,600 mm) to Estrada de Ferro Santos a Jundiaí
Estrada de Ferro Santos a Jundiaí (Brazil) 2 510–511 5 ft 3 in (1,600 mm)
Total 456

ALCO RS1 No. 292 at Conrad Yelvington Distributors (CYXX) in Orlando, FL.

(Meloaraujo, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons)



Several examples exist at tourist railways and railway museums, including:

  • Boone & Scenic Valley Railroad's RS-1 purchased in 1951 by the Lake Superior and Ishpeming Railroad as No. 1002, sold to the Calumet & Hecla Railroad in 1967 as No. 205. Later purchased by Continental Grain Company, Marshalltown, IA c. 1975. Donated to the Iowa Railroad Historical Society, Boone & Scenic Valley Railroad in 1996, painted and lettered as Minneapolis and St. Louis Railway No. 244.
  • Consumers Power (CPOX) 401 1951 built RS-1 No. 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.
  • Eastman Kodak Company 9 (built as Chicago & Western Indiana 260, sold to Genesee & Wyoming in 1971 and then to EKC) is preserved at the Rochester & Genesee Valley Railroad Museum.
  • Livonia Avon & Lakeville 20 (built as Lake Erie, Franklin & Clarion 20, sold to Livonia Avon & Lakeville) is preserved at the Rochester & Genesee Valley Railroad Museum.
  • Green Mountain Railroad 405 (former Rutland Railway 405, serial number 79575)
  • Catskill Mountain Railroad No. 400 (out of service & under repair) and No. 401 (operating) tourist train in Kingston NY.
  • Duluth, South Shore and Atlantic Railway No. 101, previously the only known locomotive existing from that railroad, is at the Lake Superior Railroad Museum and has been restored for occasional use on the North Shore Scenic Railroad.
  • Algers, Winslow and Western Railway No. 4 - Built as Duluth, South Shore and Atlantic Railway No. 103, it is currently in service on the French Lick Scenic Railway, a line operated by the Indiana Railway Museum.
  • Ann Arbor Railroad No. 20 is owned by the Southern Michigan Railroad Society in Clinton, MI and on loan to Shepherd, MI Railroad Depot Museum and Display.
  • Ann Arbor Railroad No. 21 is owned by the Southern Michigan Railroad Society in Clinton, MI. No. 21 is set to undergo cosmetic and operational repairs and a return to operational status by the end of 2015.
  • Soo Line 350 survives on display at the Whippany Railway Museum in New Jersey as Morristown & Erie 21.
  • Former Washington Terminal 57 is privately owned and undergoing mechanical restoration on the Allentown and Auburn Railroad in Topton, Pennsylvania.
  • Great Northern 182 is on display at the West Coast Railway Heritage Park in Squamish, British Columbia.
  • Chicago, Rock Island & Pacific 743 is on display at the Oklahoma Railway Museum in Oklahoma City, OK.
  • Two RS-1s are on display at the US Department of Energy's Hanford Site's B Reactor along with two flatcars.



Type and origin
Power type: Diesel-electric
Builder: American Locomotive Company; Montreal Locomotive Works
Model: RS-1
Build date: March 1941 – March 1960
Total produced: 469
​• AAR B-B
Gauge: 4 ft 8+1⁄2 in (1,435 mm) standard gauge; 5 ft 3 in (1,600 mm), Brazil
Trucks: AAR type B
Wheel diameter: 40 in (1,016 mm)
Minimum curve: 57° (116.14 ft or 35.40 m)
Wheelbase: 40 ft 5 in (12.32 m)
Length: 55 ft 5+3⁄4 in (16.91 m)
Width: 10 ft 0 in (3.05 m)
Height: 14 ft 5 in (4.39 m)
Locomotive weight: 247,500 lb (112,300 kg)
Fuel capacity: 1,000 US gal (3,800 L; 830 imp gal)
Prime mover: Alco 244T, 539T
Engine type: In line Four stroke diesel
Aspiration: Turbocharger
Displacement: 1,595 cu in (26.14 L) per cylinder; 9,572 cu in (156.86 L) total
Generator: GE GT-553-C DC generator
Traction motors: (4) GE 731 DC traction motors
Cylinders: 6
Cylinder size: 12+1⁄2 in × 13 in (318 mm × 330 mm)
Locomotive brake: Independent air
Train brakes: Air
Performance figures
Maximum speed: 65 mph (105 km/h)
Power output: 1,000 hp (746 kW)
Tractive effort: 40,425 lbf (179.82 kN)
Locale: North America, Brazil, Saudi Arabia