An EMD Model 40 at the Travel Town Museum in Los Angeles, California.

(Klaus Nahr from Germany, CC BY-SA 2.0 <>, via Wikimedia Commons)



The EMD Model 40 was a two-axle diesel-electric switcher locomotive built by Electro-Motive Corporation (EMC), and its corporate successor, General Motors' Electro-Motive Division (EMD) between August 1940 and April 1943. Nicknamed "critters", eleven examples of this locomotive were built. Powered by twin General Motors Detroit Diesel 6-71 diesel engines, which produce a combined 300 horsepower (224 kW). It's drivetrain is unusual because the two diesel engines are used to drive the electric DC generator from both sides, one with clockwise rotation and the other with counter-clockwise rotation.

Original buyers for the Model 40 included the Electro-Motive Corporation/Electro-Motive Diesel Plant, 1 unit (used as the No. 2 plant switcher), Defense Plant Corporation, 4 units, the United States Army, 3 units, the United States Navy, 2 units, and the General Motors Cleveland Diesel Division, 1 unit.

In total EMC/EMD manufactured eleven Model 40s during the period April 1940 - April 1943.


Electro-Motive Demonstrator No. 1134.

(Electro-Motive Corp., W. Lenheim Collection)


Roster of locomotives

  • s/n 1134: Built as EMC 1134 (demonstrator), to McKinnon Industries (GM Canada), to Andrew Merrilees, later sold to Devco Railway No. 20, retired to Museum of Industry, Stellarton, Nova Scotia, and currently stored out of public display.
    s/n 1308: Built for Defence Plant Corp. (Des Moines, IA), to Old Ben Coal (on site before 1956), purchased by Precision Engineering for parts (around 1968), scrapped.
  • s/n 1309: Built for US Rubber, to Penn Dixie Cement, retired to Lake Superior Railroad Museum at Duluth, Minnesota.
  • s/n 1834: Built as USAX 7403, deemed surplus at the end of 1946 and sold to Buffalo Slag. Later sold to Cushing Stone Company of Amsterdam, New York and still on property, operational into the 1990s.
  • s/n 1835: Built as DPC No. 2, to American Steel Foundry 51, to Lipsett Steel Foundries, to Calumet Steel, donated to Hoosier Valley Railroad Museum in North Judson, Indiana.
  • s/n 2284: Built as USAX 7952, to Acme Newport Steel, Newport, KY as NPTX No. 1. Owned and restored by Professional Locomotive Services in East Chicago, Indiana.
  • s/n 2285: Built as USAX 7953, to Gulf South Terminal Warehousing (somewhere between 1946 and 1949), to American Creosote Works (acquired 1950–56), resold to Coastal Sand & Gravel (Lacombe, LA); operation abandoned by the 1980s, hulk of engine still on site.
  • s/n 2286: Built as USAX 7954, to Sanderson & Porter Construction (contractors for West Penn Power), moved to West Penn Power - Mitchell Plant, transferred to West Penn Springdale Station, to Hagerstown Roundhouse Museum, leased to Walkersville Southern Railroad, Walkersville, Maryland.
  • s/n 2287: Built as USN No. 4, used during WWII by the Naval Ordinance Plant in York, PA. Remained on site, transferred to the American Machine and Foundry Company (AMF) and subsequently Harley-Davidson. Now on display at the York County History Center's Agricultural and Industrial Museum in York, Pennsylvania.
  • s/n 2288: Built as USN No. 56-00323, to Douglas Aircraft Industrial Reserve Plant (later McDonnell Douglas), retired to Travel Town Museum, Los Angeles, California.
  • s/n 2289: Built as GM Cleveland (unknown number), transferred to GM-EMD South Chicago Plant 2, out of use by mid 1970s, scrapped.



Type and origin
Power type: Diesel-electric
Builder: General Motors Electro-Motive Division (EMD)
Model: Model 40
Build date: April 1940 – April 1943
​• Whyte 0-4-0DE
• UIC Bo
Gauge: 4 ft 8+1⁄2 in (1,435 mm) standard gauge
Locomotive weight: 84,000 lb (38,000 kg)
Fuel type: Diesel fuel
Prime mover: (2) Detroit Diesel 6-71
Engine type: Inline two-stroke diesel
Generator: DC generator
Traction motors: DC traction motors (2)
Cylinders: 6 (2)
Transmission: Diesel-electric
Locomotive brake: Westinghouse 14-ET air brake
Couplers: Janney
Performance figures
Power output: 300 hp (224 kW)
Nicknames: Critters
Locale: North America