EMD "SW8" Locomotives

Last revised: February 15, 2024

By: Adam Burns

During the era of Electro-Motive's 567 prime mover the builder manufactured numerous switchers in a variety of horsepower ratings.

Over time, the more powerful models in the 1,000-1,500 horsepower range witnessed the highest sales although EMD's product was so popular at the time even its lighter switchers enjoyed success.

The SW8 was once such example that saw more than 300 manufactured in the United States and Canada between 1950-1954.

Once again, interest for the model varied from major Class I's to private industries and short lines.  Even the U.S. Army acquired 41 examples.

The resiliency of the SW series is something to behold as SW8's can still be found in operation throughout North America.  It can be found in service ranging from short lines and industrial settings to pulling excursion trains. 


Rock Island SW8 #830 lays over at Hodges, Texas on January 29, 1984. At the time of this photo the locomotive was en route from El Reno, Oklahoma to the former Biddle Yard at Little Rock, Arkansas where it handled remaining clean up operations on the old Southern Division. Mike Bledsoe photo. American-Rails.com collection.

History and Background

The SW8 began production in September, 1950 when Wabash #120-121 rolled out of the La Grange facility. 

In addition, with Electro-Motive's Canadian subsidiary (General Motors Diesel) opening its doors in London, Ontario during 1949 the new builder also began manufacturing the switcher.

Its first included four units for Canadian Pacific (6700-6704) that were completed in November, 1950.

Outwardly, the SW8 was not drastically different from the SW7, or even the NW2, sporting EMD's classic tapered hood near the cab.  However, one external difference was a single, centered exhaust stack instead of two, the result of the switcher's 8-cylinder power plant.  

As Bob Hayden notes in his book, "Diesel Locomotives Cyclopedia: Volume 2," the lighter powered SW8, SW900, SW900M, and SW600 were virtually identical.

Jerry Pinkepank goes on to state in his book, "Diesel Spotter's Guide," as all of these models used the same carbody the only way to tell the SW8 apart from the others was the louvers; it featured six in the battery box behind the cab while the others had only five.

Internally, the SW8 sported the 8-cylinder, 567B prime mover that could produce 800 horsepower.   While this rating was similar to other switchers in its class, which ranged from 600-900 horsepower, interestingly it was far less than the 1,200 horsepower SW7.

Electro-Motive's model classification system for switchers is difficult to follow as the meaning given to the letters and numbers were changed more than once.

Erie Lackawanna SW8 #365, still in its Delaware, Lackawanna & Western markings (built as #505), lays over at the former DL&W roundhouse and shops in Scranton, Pennsylvania during the early 1960s. American-Rails.com collection.

While several well known lines purchased the SW8, such as New York Central, Wabash, Lehigh Valley, and Boston & Maine several private industries also acquired the locomotive. 

Names here included Wheeling Steel (who bought numerous examples of EMD's various switchers), Pittsburgh Coke & Chemical Company, and Columbia Iron & Steel.

Again, these wide range of buyers can be explained by the intended use EMD designed the locomotive which included yard duty, light branch line work, and shuffling cars through industrial settings.

Data Sheet

Entered Production9/1950 (Wabash #120-121)
Years Produced9/1950 - 1/1954
EMD ClassSW8
Engine567B (8 Cylinder)
Engine BuilderEMD/GM
Length44' 5"
Height (Top Of Rail To Top Of Cab)14' 6"
Width9' 11 1/2"
Weight230,000 Lbs
Fuel Capacity600 Gallons
Air CompressorWXO (Gardner-Denver)
Air Brake Schedule6BL (Westinghouse)
Truck TypeGRS Rigid Bolster, Drop-Side Equalizer (AAR Type-A)
Truck Wheelbase8' 0"
Wheel Size40"
Traction MotorsD27 (4), EMD/GM
Traction GeneratorD15C, EMD/GM
Auxiliary GeneratorEMD/GM
MU (Multiple-Unit)Optional
Dynamic BrakesNo
Gear Ratio62:15
Tractive Effort/Starting57,000 Lbs
Tractive Effort/Continuous36,000 Lbs at 11.0 mph
Top Speed65 mph

Production Rosters


(Total Built = 302)

Owner Road Number Serial Number Order Number Completion Date Quantity
Poplar Ridge Coal80111371404812/19511
Rock Island811-81311694-1169661119/19503
Chicago River & Indiana (New York Central)9600-960111780-1178140599/19502
Electro-Motive (Demonstrator)800*12463615410/19501
Wheeling Steel1152-115312464-12465615511/19502
Donora Southern Railroad802-81012989-1299740823/19519
Lehigh Valley250-25513151-13156618512/19506
Tennessee Coal, Iron & Railroad750-75413259-13263618811/19505
Great Northern98-9913304-1330540896/1951-8/19512
Louisiana & North West40-4113512-13513618912/19502
Electro-Motive (Demonstrator)801**13514615410/19501
Monessen Southwestern Railway2213574622012/19501
Lake Terminal Railroad821-82413856-1385962242/1951-3/19514
Donora Southern Railroad8111386040828/19511
DeQueen & Eastern RailroadD-31395262263/19511
Lehigh Valley256-26114027-1403240928/1951-9/19516
Lehigh Valley262-26314056-1405741046/1951, 9/19512
Delaware, Lackawanna & Western501-50514063-1406740968/19515
U.S. Steel1091418762566/19511
Chicago, West Pullman & Southern421428262476/19511
Wabash Railroad125-12614418-1441962809/19512
Lehigh Valley264-27314489-1449841049/195110
Cincinnati Union Terminal30-3414564-1456862646/1951-8/19515
Chicago & North Western (Chicago, St. Paul Minneapolis & Omaha)126-12914663-1466660959/19514
Woodward Iron Company6014986625512/19511
U.S. Army2000-204014995-1503570084/1951-6/195141
New York Central9602-960715498-1550341092/19526
Tennessee Coal, Iron & Railroad77015603634412/19511
Delaware, Lackawanna & Western506-50915727-1573063406/19524
Lakeside & Marblehead13-1415735-1573641601/19522
Colorado & Wyoming Railway201-20915737-15745626912/19519
Ludington & Northern Railway161575563511/19521
Monessen Southwestern Railway261582362271/19521
Texas & Pacific (Missouri Pacific)811-81815830-1583763601/19528
Pittsburgh Coke & Chemical41587241401/19521
Colorado & Wyoming Railway210-21215940-1594262693/19523
Atlantic Coast Line50-5915949-1595863733/195210
New York Central9608-962116183-1619641442/195314
New York Central9622-962716324-1632941442/19536
New York, Chicago & St. Louis (Nickel Plate Road)107-11416352-1635941393/1952-4/19528
Rock Island814-82216609-1661741574/1952-6/19529
Rock Island823-82416618-1661941856/19522
Rock Island825-83516623-16633418511/195211
Woodward Iron Company611669163563/19521
Tremont & Gulf Railroad75, 7716807-16808639511/19522
Chicago, West Pullman & Southern43-4416825-16826638111/19522
Chicago, West Pullman & Southern45-4616827-16828646211/19522
Chicago & North Western80116889412411/19521
Canton Railroad4016900417111/19521
Reserve Mining Company12001692564126/19521
Reserve Mining Company12011697164126/19521
Lehigh Valley275-27616972-16973640912/19522
Lehigh Valley27416974643012/19521
Cincinnati Union Terminal35-3717065-17067641010/19523
Southern Pacific (Texas & New Orleans)12-1617159-1716341654/19535
Bamberger Railroad601-60217229-1723064437/19522
Southern Pacific4604-461117331-1733841801/1953-3/19538
Wabash Railroad128-13217589-1759364152/19535
South Shore Railway121765964801/19531
Delaware, Lackawanna & Western510-51117885-1788664875/19532
Electro-Motive (Demonstrator)500***1792465001/19531
Unity Railways531810064774/19531
Merchants Despatch Transportation Company151817365053/19531
Boston & Maine800-80718200-1820742245/1953-6/19538
New Orleans Union Passenger Terminal1-318294-18296416712/19533
Southern Pacific4612-462118347-1835641796/1953-7/195310
Roscoe, Snyder & Pacific Railway2001861865208/19531
Canton Railroad411867442018/19531
Wichita Falls & Southern Railroad801-80218708-1870942358/19532
Columbia Iron & Metal11873942409/19531
Cedar Rapids & Iowa City Railway91-9318784-18786423210/19533
Rock Island836-83818865-18867424511/19533
Aliquippa & Southern Railroad800-80219071-19073425012/19533
North Louisiana & Gulf Railroad37-3819390-19391426212/19532
Canton Railroad42-4319493-1949442591/19542
Southern Pacific4622-462319495-1949642561/19542

*  Became Illinois Terminal #725.  Sold as order number 6285.

**   Became Georgia Northern Railway #801.

*** Became Cuyahoga Valley Railway #855.  Sold as order number 4314.


(Total Built = 7)

SW8's completed from trade-in units, reusing the same serials as their predecessors.

Owner Road Number Serial Number Order Number Completion Date HeritageQuantity
Detroit, Toledo & Ironton900-9011324-1325WO45251-452525/1952Ex-DT&I SW1's #900-901.2
Great Northern10177775066/1953Ex-Great Northern NW1 #5102.1
Lehigh Valley128-129787, 830750910/1953-11/1953Ex-Lehigh Valley NW1's #128-129.2
Kansas City Terminal61731751112/1952Ex-Kansas City Terminal NW #61.1
Steelton & Highspire26699751412/1953Ex-Patapsco & Back Rivers Railroad SW #62.1


(Total Built = 65)

Owner Road Number Serial Number Order Number Completion Date Quantity
Canadian Pacific6700-6703A110-A113C10111/19504
Wabash Railroad122-124A145-A147C1061/19513
Canadian National8500-8521A180-A201C1122/1951-6/195122
Canadian Pacific6704-6709A232-A237C1156/1951-7/19516
Essex Terminal102A238C1208/19511
Dominion Foundries & Steel11A276C1486/19521
Algoma Steel50A277C1506/19521
Wabash Railroad127A278C1228/19511
Dominion Iron & Steel11-12A279-A280C1434/19522
Algoma Central & Hudson Bay141A281C1444/19521
Canadian National8522-8533A284-A295C1258/1951-11/195112
Canada & Gulf Terminal356A296C12611/19511
Algoma Central & Hudson Bay140A297C12712/19511
Steel Company Of Canada (Stelco)71-73A300-A302C12912/19513
Steel Company Of Canada (Stelco)74-77A516-A519C1644/1953-5/19534
Dominion Foundries & Steel12A533C16711/19531
Essex Terminal104A612C1792/19541


  • Foster, Gerald. A Field Guide To Trains. New York: Houghton Mifflin, 1996.
  • Hayden, Bob. Diesel Locomotives: Cyclopedia, Volume 2 (Model Railroader). Milwaukee: Kalmbach Publishing Company, 1980.
  • Marre, Louis A. Diesel Locomotives: The First 50 Years, A Guide To Diesels Built Before 1972.  Milwaukee: Kalmbach Publishing Company, 1995.
  • Pinkepank, Jerry A. Diesel Spotter's Guide.  Milwaukee: Kalmbach Publishing Company, 1967.
  • Solomon, Brian.  EMD Locomotives.  Minneapolis: MBI Publishing Company, 2006.

In Canada, these companies included Dominion Foundries & Steel, Algoma Steel, Dominion Iron & Steel, and the Steel Company Of Canada (Stelco).

As for the cow/calf TR6 just twelve sets were built; one demonstrator (that went to Southern Pacific), eight for the Oliver Iron Mining Company, and three more to SP.

Once again, the reliability and versatility of the SW series has been well represented in the SW8 as numerous models continue to perform admirably in all types of settings.

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It is difficult to truly articulate just how much material can be found at this website. 

It is quite staggering and a must visit!