Santa Fe Railway No. 2098

(Mr Snrub at en.wikipedia, GFDL <>, via Wikimedia Commons)


Alco rectangular block letter logo.


The ALCO RS-2 is a 1,500–1,600 horsepower (1,100–1,200 kW) B-B diesel-electric locomotive built by the American Locomotive Company (ALCO) from 1946 to 1950. ALCO introduced the model after World War II as an improvement on the ALCO RS-1. Between 1946 and 1950, 377 examples of the RS-2 were built, primarily for American and Canadian customers.

ALCO discontinued the RS-2 in 1950 in favor of the very similar RS-3, which was more popular. Several examples have been preserved.


Design and development

The RS-2 was a further development of the road switcher concept inaugurated with the RS-1. Externally, the RS-2 bodywork was more rounded. A more significant change was the switch from the RS-1's ALCO 539 engine to the ALCO 244, adding horsepower to better handle heavy road service. The new engine was a turbocharged four-stroke V12 diesel engine with a 9 in × 10+1⁄2 in (229 mm × 267 mm) bore and stroke developing 1,500 (later 1,600) hp at 1,000 rpm. Compared to the 539, it had a smaller cylinder and higher cylinder speed. Production of the RS-2 was delayed several months while ALCO worked out the new four-pipe divided low-rise manifold for the GE constant-pressure RD-1 turbocharger. The 244 engine was not a reliable design, however, and was replaced in less than ten years by the Alco 251 engine.



A total of 377 RS-2s were produced: 368 by the American Locomotive Company and nine by ALCO subsidiary Montreal Locomotive Works in Canada. Eight of the ALCO RS-2s were exported to Canada.

The RS-2 has a single, 12-cylinder, model 244B engine, developing 1,500 horsepower (1,100 kW).

Thirty-one locomotives built by Alco between February and May 1950 were powered by a 12-cylinder 244C 1,600 horsepower (1,200 kW) engine.

ALCO built the RS-2 to compete with EMD, Fairbanks-Morse, and Baldwin Locomotive Works. In 1947, Fairbanks-Morse introduced the 1,500 hp (1.1 MW) H-15-44. Also in that year, Baldwin introduced the 1,500 hp (1.1 MW) DRS-4-4-1500. In the case of ALCO, Fairbanks-Morse, and Baldwin, each company increased the power of an existing locomotive line from 1,500 to 1,600 hp (1.1 to 1.2 MW), and added more improvements to create new locomotive lines.

EMD, however, kept its competing GP7 at 1,500 hp (1.1 MW). In 1954, EMD introduced the GP9. It was rated at 1,750 hp (1.30 MW).

EMD produced 2,734 GP-7s. ALCO/MLW produced 377 RS-2s, and 1,418 RS-3s. Fairbanks-Morse produced 30 H-15-44s, and 296 H-16-44s. Baldwin produced 32 DRS-4-4-1500s, and 127 AS-16s.

The Delaware and Hudson Railway rebuilt 13 of its RS-2s for passenger service, including on the Laurentian. The D&H added a steam generator and 1,600-US-gallon (6,100 L; 1,300 imp gal) water tank.


Original owners

Manufactured by ALCO
ALCO and Montreal Locomotive Works in Canada built 377 locomotives. Cited and mirrored roster.

Railroad Quantity Road numbers
American Locomotive Company (demonstrators) 4 1500, 1500:2, 1501, 1600
Alton and Southern Railway 15 28–42
Atlantic and Danville Railway 6 101–106
Belt Railway of Chicago 9 450–458
Birmingham Southern Railroad 1 150
Boston and Maine Railroad 9 1501–1504, 1530–1534
Canadian Pacific Railway 5 8400–8404
Carolina & North-Western Railway 4 1–4
Chesapeake and Ohio Railway 2 5500–5501
Chicago and North Western Railway 1 1503
Chicago Great Western Railway 8 50–57
Chicago, Indianapolis and Louisville Railroad 7 21–27
Chicago, Rock Island and Pacific Railroad 5 450–454
Danville and Western Railway 2 1–2
Delaware and Hudson Railway 26 4000–4025
Detroit and Mackinac Railway 6 466–469, 4610, 481
Elgin, Joliet and Eastern Railway 10 800–809
Erie Railroad 19 900–913, 1000–1004
Great Northern Railway 20 200–219
Green Bay and Western Railroad 4 301–304
Gulf, Mobile and Ohio Railroad 14 1501–1514
Kennecott Copper Corporation 9 100–102, 104–107, 902–903
Lake Superior and Ishpeming Railroad 3 1501–1503
Lehigh and New England Railroad 13 651–663
Lehigh Valley Railroad 5 210–214
Macon, Dublin and Savannah Railroad 3 1700–1702
Maine Central Railroad 5 551–555
Missouri-Illinois Railroad 1 61
New York, New Haven and Hartford Railroad 17 0500–0516
New York Central Railroad 23 8200–8222
Oliver Iron Mining Company 8 1100–1107
Ontario Northland Railway 2 1300–1301
Roberval and Saguenay Railway 1 19
St. Louis and Belleville Electric Railway 1 700
St. Louis-San Francisco Railway 5 550–554
Seaboard Air Line Railroad 29 1600–1628
Southern Railway 30 2101–2130
Spokane, Portland and Seattle Railway 3 60–62
Texas and Pacific 1 23
Texas Pacific-Missouri Pacific Terminal Railroad of New Orleans 2 21–22
Toledo, Peoria and Western Railway 7 200–206
Union Pacific Railroad 5 1191–1195
Union Railroad 12 601–612
Western Maryland Railway 5 180-184
Youngstown and Northern Railroad 1 231
Total 368

Manufactured by Montreal Locomotive Works

Railroad Quantity Road numbers
Canadian Pacific Railway 4 8405–8408
Napierville Junction Railway 2 4050–4051
Ontario Northland Railway 2 1302–1303
Roberval and Saguenay Railway 1 20
Total 9

Texas State Railroad's ALCO RS-2.

(Rvassar, CC BY-SA 3.0 <>, via Wikimedia Commons)



Very few RS-2s survive today. Three former Kennecott Copper locomotives are preserved, including Kennecott Copper 908 (former number 104) at the Western Pacific Railroad Museum at Portola, California. KCC 908 once served the mines out of Ely, Nevada along the Nevada Northern Railway. Nevada Northern 105 is at Ely, Nevada, it was formerly the Kennecott Copper 105. Kennecott Copper 103 is at the San Diego Railroad Museum in Campo, California. It is painted as Santa Fe 2098. Another RS-2 is in active service on the Texas State Railroad (rebuilt as an RS-2-CAT). It is the former Union Railroad 608. The first production RS-2, originally sold to the Detroit & Mackinac RR as their number 466, was fully operable in freight service on the Michigan Southern Railroad (1989) until a few years ago. As of September 2005, the 466 was stored out of service near the Michigan Southern's office in White Pigeon, Michigan, it was finally scrapped in December 2011. The former Detroit & Mackinac 469 was sold to Waymore Power and may be restored. The former Elgin Joliet and Eastern 801 is preserved in Jala, Mexico as a Las Encinas SA de CV 801. And MLW built Roberval and Saguenay 20 is at the Canadian Railway Museum.



Type and origin
Power type: Diesel-electric
Builder: American Locomotive Company; Montreal Locomotive Works
Model: RS-2
Build date: October 1946 – May 1950
Total produced: 377
​• AAR B-B
Gauge: 4 ft 8+1⁄2 in (1,435 mm) standard gauge
Trucks: AAR type B
Wheel diameter: 40 in (1,000 mm)
Minimum curve: 57° (104.79 ft or 31.94 m)
Wheelbase: 39 ft 4 in (11.99 m)
Length: 56 ft (17 m)
Width: 10 ft (3.0 m)
Height: 14 ft 5 in (4.39 m)
Locomotive weight: 249,600 lb (113,200 kg)
Fuel capacity: 800 US gal (3,000 L; 670 imp gal)
Prime mover: ALCO 244
Engine type: V12 Four-stroke diesel
Aspiration Turbocharger
Generator: GE 5GT-564B-1
Traction motors: (4) GE 752-A
Cylinders: 12
Cylinder size: 9 in × 10+1⁄2 in (229 mm × 267 mm) bore x stroke
Performance figures
Power output: 1,500 hp (1.119 MW) @ 1,000rpm; later models: 1,600 hp (1.193 MW)
Tractive effort: 62,500 lb (28,300 kg)
Locale: North America