EMD SW1
| Company type | Division |
|---|---|
| Industry | Locomotive manufacturing |
| Predecessor | Electro-Motive Corporation (EMC) |
| Founded | 1938 |
| Founder | General Motors |
| Fate | Continued as EMD division of General Motors |
| Headquarters | La Grange, Illinois , United States |
Area served | Worldwide |
| Products | Diesel-electric locomotives (including SW1) |
| Owner | General Motors |
| Parent | General Motors |
{{Infobox locomotive | name = EMC/EMD SW1 | powertype = Diesel-electric | image = Hugh llewelyn 6589 (5961018035).jpg | caption = PC #8589, retaining PRR paint scheme, performing switching duties in Pittsburgh during 1970 | builder = General Motors Electro-Motive Corp (later Division) (EMC/EMD) | buildmodel = SW1 | builddate = – | totalproduction = 661 | aarwheels = B-B | gauge = | trucks = AAR Type A or B | wheeldiameter = | minimumcurve = 57° () | wheelbase = | length = | width = | height = | locoweight = | primemover = EMD 6-567B or 6-567A or 6-567AC | enginetype = V6 2-stroke diesel | aspiration = Gear-driven Roots blower | displacement = | cylindercount = 6 | cylindersize = | gear ratio = 62:15 | maxspeed = | poweroutput = | generator = GM D-4 | tractionmotors = (4) GM D-7A | tractiveeffort = |} The EMD SW1 is a diesel-electric switcher locomotive produced by General Motors' Electro-Motive Diesel division between December 1938 and November 1953. Final assembly was completed at EMD’s facility in LaGrange, Illinois. This model replaced earlier EMD switchers by introducing the company’s proprietary V6 EMD 567 engine, which generated 600 horsepower. A total of 661 units were manufactured, with production suspended from March 1943 until September 1945 due to World War II.
The SW1 launched EMD’s extensive SW series of switchers and was followed by the EMD SW7 in 1949 and the EMD SW8 in 1950. Manufacturing of the SW1 ceased in November 1953, succeeded by the similarly powered EMD SW600, which commenced production in February 1954.
Locomotive name
The designation SW1 was assigned by EMD to reflect its power rating and design characteristics: "S" representing approximately 600 horsepower, "W" signifying its welded frame construction, and "1" differentiating it from the earlier EMD SW. As additional, more powerful models were introduced during the 1950s, the "SW" acronym came to denote "switcher."
Engine and powertrain
The SW1 marked the debut of a six-cylinder variant of the 567 engine series (later upgraded to the 567A) for EMC/EMD switchers, delivering horsepower at 800 rpm. This mechanically aspirated V6 two-stroke engine had a bore and stroke that resulted in displacement per cylinder. Power was transmitted through a DC generator driving four traction motors arranged in a B-B wheel configuration utilizing AAR type A switcher trucks. Since 1939, EMC/EMD produced all major components internally.
Production changes
During its production span, the SW1 underwent various internal enhancements such as adopting the post-war 567A engine model. External modifications included changing to flat-topped center cab windows after mid-1950, shifting from a two-stage to a single taper design between hood and cab, and replacing short exhaust stacks with EMD’s signature conical switcher stack to improve operator visibility. Early versions featured a single large headlight, whereas later models were equipped with dual sealed-beam headlights.
Original owners
... [table truncated for brevity] ...- Seven locomotives initially built as EMD demonstrators were subsequently sold to different railroads.
- In recent times, numerous SW1 units continue in operational roles or are conserved by entities such as Amtrak (#737), Metra (yard operations), and Wilmington & Western Railroad.
- The locomotive sold by Metra in 2021 was reportedly among the oldest diesel engines in active use within Illinois and the United States not housed in a museum.
Preservation
- Andersen Windowalls 3110, initially Wabash Railroad 110 and subsequently Norfolk and Western Railway 3110, constructed in June 1949, remains operational at the Minnesota Transportation Museum.
- Arkansas–Oklahoma Railroad 536 continues active freight service, featuring a paint scheme inspired by Rock Island.
- Ballard Terminal Railroad 98, originally Milwaukee Road 1619 and later Seattle and North Coast Railroad 52, is engaged in revenue freight operations.
- Baltimore and Ohio 8408 along with Lehigh Valley 114 are both functional at the Wilmington and Western Railroad.
- Billings Grain Terminal 84, originally built as Chicago, Burlington and Quincy Railroad 9139 in 1939, was purchased by St Johns River Companies in 2022 for restoration efforts. After being renumbered to 84 following the 1970 creation of Burlington Northern Railroad, it served five years before transferring to Davenport, Rock Island and Northwestern, and later to a grain elevator in Billings, Montana.
- Black River and Western Railroad maintains Lehigh Valley 112 and Pennsylvania Railroad 9206 in working condition.
- Boston and Maine units 1109 (housed at the Railroad Museum of New England) and 1127 (now part of the Danbury Railway Museum collection) have been preserved.
- BRMX 1849 (formerly Boston and Maine 1113) operates at the Berkshire Scenic Railway located in Lenox, Massachusetts.
- Cargill 6751, one of Electro-Motive’s earliest SW1 models built in 1940 (originally B&O No.213/8413), was leased to Washington and Old Dominion Railroad until its closure in 1968. Following multiple ownership changes, Cargill utilized it at its Globe Mill in Ogden, Utah. Donated in 2010, it is currently exhibited at the Utah State Railroad Museum.
- Commonwealth Edison 15 is frequently operated at the Illinois Railway Museum.
- Dardanelle & Russellville 16 (formerly Chicago & Eastern Illinois 99/Missouri Pacific 6001) remains in active service.
- Eureka Springs & North Arkansas Railway’s unit 4742 (ex-Chicago & Eastern Illinois 98) runs on an excursion route.
- Heart of Dixie 904 (previously Memphis Union Station 10) is preserved at the Heart of Dixie Railroad Museum.
- Holly Sugar 1, EMC’s first SW1 constructed in 1939 as Southern Pacific Lines 1000, is preserved at the California State Railroad Museum. It served Southern Pacific until retirement during the 1970s before being sold to Holly Sugar.
- Louisville & Nashville Railroad unit 13 is displayed at Alabama’s Foley Railroad Museum.
- Milwaukee Road 1626, built June 1939 with its original Electro-Motive Division prime mover intact, remains operational at the Milwaukee Road Heritage Center.
- Monon Railroad’s first diesel locomotive, number 50, is currently leased to Hoosier Valley Railroad Museum for restoration after sustaining damage during relocation; a former Milwaukee Road unit numbered 1613 was scrapped in July 2018.
- New York Central unit 705 (ex-Louisville and Nashville number 14) is active on the Adirondack Scenic Railroad.
- Northern States Power number 4 (ex-Chicago, Burlington and Quincy Railroad #9146) operates at Gopher State Railway Museum.
- Peabody Coal Company locomotive number 470 (formerly Delaware, Lackawanna and Western #436) is displayed statically at Indiana’s Museum of the Coal Industry in Lynnville.
- Pennsylvania Railroad locomotives numbered 9206 (operating on Black River and Western) and 9408 (functional at Railway Museum of Greater Cincinnati) have been preserved.
- Pere Marquette Railway number 11 runs at the Baltimore & Ohio Railroad Museum.
- Portland Traction Company unit number 100 operates at Oregon Rail Heritage Center; it is distinguished as the only preserved interurban diesel equipped with trolley poles.
- Sacramento Northern number 402 (ex-Western Pacific #502) is preserved within the California State Railroad Museum collection.
- SMS Rail Service’s former Pennsylvania Railroad unit number 9423 is stored in Bridgeport, New Jersey.
- Southern Pacific Lines number 1006 has been restored to its original appearance and operates regularly pulling passenger trains at Southern California Railway Museum.
- Western Pacific Railroad unit number 501 (EMC demonstrator #906), Western Pacific's inaugural diesel-electric locomotive, is preserved at the Western Pacific Railroad Museum located in Portola, California.
- Western Rail, a dealer and lessor of used locomotives, owns WRIX number 1001 (built June 1949 as NYC #609 second unit).
- Zanesville & Western Scenic Railroad operates former Pennsylvania Railroad PRR5999 on excursions near Fultonham, Ohio.
- Dura-Bond, previous owner of Turtle Creek Industrial Railroad, utilizes unit #462 as a switcher on private trackage close to McKeesport, Pennsylvania.
See also
References
- (July 2005), "Preservation Briefs", Trains Magazine, p. 71.
- TrainWeb.com. The Unofficial EMD homepage. Accessed January 7, 2005. Features detailed builder records for early EMD models.
- Andersen Windows 3110. Retrieved December 7, 2012.
- EMD Product Reference Data Card (January 1, 1959) containing specifications for the 567AC engine as originally built.
- Billings Grain Terminal 84, https://www.stjohnsrail.com/restore84
External links
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