Alco "RS2" Locomotives: Roster, Horsepower, Specs

Last revised: December 27, 2024

The RS2 was Alco's second entrant in its Road Switcher series. Buoyed by the success of its earlier RS1 model, the American Locomotive Company released a more powerful version following the end of World War II.

Externally, the RS2 closely resembles the RS3, cataloged a few years later. However, it was somewhat less powerful. At the time of the RS2's production, Alco was the leader in road-switchers.

The company had pioneered the concept, providing a rare moment in which Electro-Motive was the one playing catch up. The RS-1's were viewed favorably by the industry as railroads were quite pleased with the new lightweight, yet powerful concept.

The RS2 sold better than its earlier counterpart proving its predecessor was not a fluke. In addition, new styling and increased horsepower paved the way for the very popular RS3.

It is a true shame the builder could not build upon these early successes; with EMD's GP7 release in the late 1940's it cornered the road-switcher market. Today, the model is the least preserved of the early RS series, only a handful survive.

Photos

Lehigh Valley RS2 #211 sits outside the shops in Sayre, Pennsylvania; July, 1962. American-Rails.com collection.

Overview

The RS2 is sometimes a forgotten model in the builder's early road-switcher series. Interestingly, there are few differences between the RS2 and RS3 although the former was the first to employ Alco's very own model 244 prime mover.

Before this time the builder had employed engines supplied from McIntosh & Seymour (the model 539T), which proved to be fairly reliable in the early RS1, S1, S2, and original HH models (early switchers of the 1930s).

While the model 244 did prove its worth in the RS2 and later RS3 for secondary and light branch line duties it suffered from the same issues as the 539T in standard road service. Alco had tried the M&S prime mover in its original DL series for main line applications although mechanical issues resulted in few being sold.

The 244 experienced problems in Alco's model FA and PA, released in 1946 with the RS2. These two cab designs, one meant for freight service (FA) and the other designed to haul passenger trains (PA), replaced the DL models.

They were clad in an attractive carbody and offered excellent tractive effort but suffered mechanical issues, primarily due to the fact that the manufacturer had not spent enough research and development on the prime mover.

It was said that after World War II had ended and manufacturers were once again free of wartime restrictions Alco management wanted the 244 engine ready for production by no later than early 1946. Interestingly, despite the model's problems in heavy-haul service it proved to be quite successful in the switcher and small road switcher deigns.

A pair of handsome Delaware & Hudson RS2's lead a special fan trip through Binghamton, New York in September, 1968. Author's collection.

The Alco RS2 debuted at 1,500 horsepower, which would increase to 1,600 before production ended in March of 1950.

The first railroads to receive theirs included the Delaware & Hudson Railway and Detroit & Mackinac between November and December of 1946 (both lines remained loyal Alco customers practically until Alco left the locomotive market during the late 1960s).

Perhaps the most noticeable difference between the RS1 and RS2, outwardly, was the latter's updated, beveled carbody design also used on its successor, the RS3. With added streamlining some railroads found the RS2 more practical in passenger service than the RS1 (despite the fact that both could be equipped for such).

Delaware & Hudson RS2 #4023 was photographed here at Rouses Point, New York in the fall of 1966. This locomotive was part of a 26-unit order D&H acquired from Alco in the late 1940s. American-Rails.com collection.

Mechanically, the RS2 used air brakes and compressors from Westinghouse while the model 752 traction motors were produced by General Electric.

The B-B truck setup (two powered axles per truck) could produce 42,500 pounds of tractive effort (nearly 10,000 pounds more than the RS1) and the RS2 came equipped with dynamic brakes.

At 55 feet, 5 inches in length it was about the same size as the earlier RS1 while the later RS3 was just slightly longer. With the RS2s finely designed carbody, horsepower, and other attributes it came to be used in applications far outside of what Alco had intended as railroads found the model quite utilitarian in either passenger service or as auxiliary power in heavy drag service.

Gulf, Mobile & Ohio RS2 #1507 is seen here at Bogalusa, Louisiana during September of 1972. Located near the Mississippi border, this small community lay along the GM&O's main line to New Orleans. Warren Calloway photo.

Data Sheet and Specifications

Alco Class	404-DL-240
Entered Production	10/30/1946 (Detroit & Mackinac #467)
Years Produced	10/30/1946-4/1950
Model Specification	E1661/A/B/C (MLW = ME5000R)
Engine	244, V-12
Engine Builder	Alco
Horsepower	1,500 (Increased to 1,600 HP in variant E1661C.)
Carbody Styling	Alco
Length (Between Coupler Pulling Faces)	56'
Weight	240,000 lbs. (Optional ballasting.)
Dynamic Brakes	Optional
Trucks	B-B
Truck Type	Swing Bolster, Drop-Side Equalizer (AAR Type-B)
Truck Wheelbase	9' 4"
Wheel Size	40"
Traction Motors	GE 726 (4) (Upgraded to GE 752 [4] in variant E1661A.)
Traction Generator	GT564A (Upgraded to GT564C in variant E1661A.)
Gear Ratio	74:18
Tractive Effort Rating	42,500 lbs. at 11 MPH.
Top Speed	65 MPH

Chicago Great Western RS2 #51 at Faribault, Minnesota; September, 1962. Rick Burn photo.

Production Rosters

Alco

Total Built = 368

Owner	Road Number(s)	Serial Number(s)	Date Built
Alco (Demonstrator)	1500 (1st), 1501 (#1500 became Monon #29, #1501 became Monon #28)	74992, 75143	1/1947
Alco (Demonstrator)	1500 (2nd): (became Boston & Maine #1500)	75942	5/1948
Alco (Demonstrator)	1600 (became Santa Fe #2110)	77918	3/1950
Alton & Southern	28, 29	75255, 75256	6/1947
Alton & Southern	30, 31	75259, 75260	7/1947
Alton & Southern	32-35	75271-75274	9-10/1947
Alton & Southern	36-38	75411-75413	11/1947
Alton & Southern	39	75565	11/1947
Alton & Southern	40, 41	75701, 75702	4/1948
Alton & Southern	42	75961	11/1948
Atlantic & Danville	101, 102	76989, 76990	7/1949
Atlantic & Danville	103-106	77426-77429	10/1949
Belt Railway of Chicago	450-458	77877-77885	12/1949
Birmingham Southern	150	77431	11/1949
Boston & Maine	1501-1504	76648-76651	3/1949
Boston & Maine	1530-1532	76652-76654	3/1949
Boston & Maine	1533-1534	76975-76976	6/1949
Canadian Pacific	8400-8404	77190-77194	9/1949
Carolina & Northwestern Railway	1-4	75687-75690	2/1948
Chesapeake & Ohio	5500-5501	76826-76827	5/1949
Chicago & North Western	1503	75573	2/1948
Chicago Great Western	50-52	76821-76823	5/1949
Chicago Great Western	53-57	77185-77189	8/1949
Chicago, Indianapolis & Louisville (Monon)	21, 22	74993, 75142	1/1947, 3/1947
Chicago, Indianapolis & Louisville (Monon)	23, 24	75144, 75261	4/1947, 8/1947
Chicago, Indianapolis & Louisville (Monon)	25-27	75394-75396	8/1947 - 10/1947
Rock Island	450-454	75952-75956	9/1948 - 10/1948
Danville & Western	1-2	76991-76992	7/1949
Delaware & Hudson	4000	74991	11/1946
Delaware & Hudson	4001-4002	74997-74998	12/1946
Delaware & Hudson	4003-4004	75131-75132	12/1946
Delaware & Hudson	4005, 4006	75137, 75141	2/1947, 3/1947
Delaware & Hudson	4007-4011	75566-75570	1/1948
Delaware & Hudson	4012-4013	76234-76235	12/1948
Delaware & Hudson	4014-4015	77541-77542	10/1949
Delaware & Hudson	4016-4024	77567-77575	11/1949
Delaware & Hudson	4025	77856	11/1949
Detroit & Mackinac	466-467	73645-73646	11/1946
Detroit & Mackinac	468-469	74986-74987	11/1946
Detroit & Mackinac	4610	74988	11/1946
Detroit & Mackinac	481	75571	1/1948
Elgin, Joliet & Eastern	800-803	75943-76946	6/1948
Elgin, Joliet & Eastern	804-806	77543-77545	10/1949
Elgin, Joliet & Eastern	807-809	77560-77562	11/1949
Erie	900-901	76973-76974	6/1949
Erie	902-904	77405-77407	9/1949
Erie	905-913	77546-77554	11/1949
Erie	950	77555	11/1949
Erie	951-954	77863-77866	12/1949
Great Northern	200-203	75145-75148	6/1947
Great Northern	204	75258	7/1947
Great Northern	205-207	75262-75264	8/1947
Great Northern	208-211	76997-77000	8/1949
Great Northern	212-214	77197-77199	9/1949
Great Northern	215-217	77400-77402	9/1949
Great Northern	218-219	77893-77894	1/1950
Green Bay & Western	301-304	77914-77917	3/1950
Gulf, Mobile & Ohio	1501-1504	76236-76239	12/1948
Gulf, Mobile & Ohio	1505-1508	76643-76646	2/1949
Gulf, Mobile & Ohio	1509-1510	77415-77416	9/1949
Gulf, Mobile & Ohio	1511-1514	77432-77435	11/1949
Kennecott Copper Corporation	100-101	75950-75951	7/1948 - 8/1948
Kennecott Copper Corporation	102	76801	4/1949
Kennecott Copper Corporation	104-107	77888-77891	12/1949
Kennecott Copper Corporation	902-903	77563-77564	11/1949
Lake Superior & Ishpeming	1501-1503	76802-76804	4/1949
Lehigh & New England	651	76647	3/1949
Lehigh & New England	652-653	77536-77537	10/1949
Lehigh & New England	654-655	77556-77557	11/1949
Lehigh & New England	656-657	77857-77858	11/1949
Lehigh & New England	658-659	77867-77868	12/1949
Lehigh & New England	660-663	77873-77876	12/1949
Lehigh Valley	210-211	76655-76656	3/1949
Lehigh Valley	212-214	77919-77921	3/1950
Macon, Dublin & Savannah	1700-1702	77538-77540	10/1949
Maine Central	551-555	76634-76638	3/1949
Missouri-Illinois Railway	61	77566	11/1949
New York Central	8200-8201	75685-75686	2/1948
New York Central	8202-8207	76241-76246	1/1949
New York Central	8208	76632	1/1949
New York Central	8209-8222	77900-77913	2/1950
New Haven Railroad	500-509	75401-75410	12/1947-1/1948
New Haven Railroad	510-516	76227-76233	11/1948 - 12/1948
Oliver Iron Mining	1100-1103	75267-75270	9/1947
Oliver Iron Mining	1104-1107	75957-75960	10/1948 - 11/1948
Ontario Northland Railway	1300-1301	76824-76825	5/1949
Roberval & Saguenay Railway	19	75265	7/1947
St. Louis & Belleville Electric Railway	700	76805	4/1949
St. Louis-San Francisco Railway (Frisco)	550-554	77436-77440	10/1949
Seaboard Air Line	1600-1603	77869-77872	12/1949
Seaboard Air Line	1604	77887	12/1949
Seaboard Air Line	1605-1608	77922-77925	3/1950
Seaboard Air Line	1609-1628	77946-77965	3/1950 - 4/1950
Southern Railway	2101-2110	76979-76988	7/1949
Southern Railway	2111-2114	76993-76996	8/1949
Southern Railway	2115-2116	77195-77196	9/1949
Southern Railway	2117-2125	77417-77425	10/1949
Southern Railway	2126	77430	11/1949
Southern Railway	2127-2130	77859-77862	12/1949
Spokane, Portland & Seattle	60, 61	77414, 77565	9/1949, 11/1949
Spokane, Portland & Seattle	62	77892	1/1950
Texas Pacific-Missouri Pacific Terminal Railroad	21, 22	75704, 75934	4/1948
Texas Pacific-Missouri Pacific Terminal Railroad	23	76633	1/1949
Toledo, Peoria & Western	200, 201	75703, 75935	4/1948
Toledo, Peoria & Western	202-203	76819-76820	5/1949
Toledo, Peoria & Western	204-205	77403-77404	9/1949
Toledo, Peoria & Western	206	77886	12/1949
Union Pacific	1191, 1192	75266, 75572	2/1947, 2/1948
Union Pacific	1193-1194	75691-75692	2/1948
Union Pacific	1195	76240	1/1949
Union Railroad	601-607	75694-75700	3/1948
Union Railroad	608-610	76828-76830	5/1949
Union Railroad	611-612	76971-76972	6/1949
Western Maryland	180	75257	6/1947
Western Maryland	181-184	77971-77974	4/1950
Youngstown & Northern	231	75574	2/1948

Montreal Locomotive Works

Total Built = 9

Owner	Road Number(s)	Serial Number(s)	Completion Date
Canadian Pacific	8405-8408	76100-76103	4/1950
Napierville Junction Railway (Delaware & Hudson)	4050-4051	76098-76099	2/1950
Ontario Northland Railway	1302, 1303	76096, 76097	1/1950
Roberval & Saguenay Railway	20	76095	12/1949

Export

Total Built = 5

Owner	Road Number(s)	Serial Number(s)	Completion Date
Algerian Railways	1-5	77895-77899	1/1950 - 2/1950

Sources

Foster, Gerald. A Field Guide To Trains. New York: Houghton Mifflin, 1996.

Kirkland, John F. Diesel Builders, The: Volume Two, American Locomotive Company And Montreal Locomotive Works. Glendale: Interurban Press, 1989.

Pinkepank, Jerry A. Diesel Spotter's Guide. Milwaukee: Kalmbach Publishing Company, 1967.

Solomon, Brian. Alco Locomotives. Minneapolis: Voyageur Press, 2009.

Napierville Junction Railway RS2 #4050, one of the two the Delaware & Hudson's subsidiary owned, lays over in Montreal, Quebec in October, 1970. American-Rails.com collection.

From a sales standpoint the RS2 was modestly successful outshopping more than 400 units (as noted in the chart above, which lists every buyer of the locomotive).

Perhaps more importantly, though, dozens of large and small railroads all over the country purchased the RS2 as well as a few private industries. The locomotive's success set the stage for the RS3, cataloged a few years later.

It should be noted that Alco's Canadian arm, the Montreal Locomotive Works, also produced eight models total between the Canadian Pacific, Ontario Northland, and Roberval & Saguenay.

Photos

A new Southern Railway RS2, #2127, sparkles in Virginia Green in this American Locomotive builder's photo from December, 1949. Warren Calloway collection.

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