An SD39 is a 6-axle

diesel-electric locomotive A diesel locomotive is a type of railway locomotive in which the prime mover is a diesel engine. Several types of diesel locomotives have been developed, differing mainly in the means by which mechanical power is conveyed to the driving whee ...

built by

General Motors Electro-Motive Division Progress Rail Locomotives, doing business as Electro-Motive Diesel (EMD), is an American manufacturer of diesel-electric locomotives, locomotive products and diesel engines for the rail industry. The company is owned by Caterpillar through its sub ...

between August 1968 and May 1970. 54 were built for American railroads. In 1966 EMD replaced all their old models with new ones having the new

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diesel. These included six-axle models SD38,

SD40 SD40 may refer to: * Canon PowerShot SD40, a digital camera * EMD SD40, a diesel-electric locomotive * South Dakota Highway 40 * SD-40 alcohol, ethanol denatured by adding denatonium benzoate {{Letter-NumberCombDisambig ...

, SDP40 and

SD45 The SD45 is a six-axle diesel-electric locomotive built by General Motors Electro-Motive Division between 1965 and 1971. It has an EMD 645E3 twenty-cylinder engine generating on the same frame as the SD38, SD39, SD40, and SDP40. As of 2022, mo ...

; the SD39 was added in 1968. All shared standard components including the frame, cab, traction alternator,

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traction motor A traction motor is an electric motor used for propulsion of a vehicle, such as locomotives, electric or hydrogen vehicles, elevators or electric multiple unit. Traction motors are used in electrically powered rail vehicles ( electric multipl ...

s, and air brakes. The difference was the power output: SD38 = from a non-turbocharged V16, SD39 = from a turbocharged V12, SD40 = from a turbocharged V16, and SD45 = from a turbocharged V20. The SD39 had the smallest prime mover and therefore had the most unused space above the frame, inside the hood between the main generator and electrical cabinet, and outside in large end "porches".

Variant

A variant was the SDL39, ordered by the

Milwaukee Road The Chicago, Milwaukee, St. Paul and Pacific Railroad (CMStP&P), often referred to as the "Milwaukee Road" , was a Class I railroad that operated in the Midwest and Northwest of the United States from 1847 until 1986. The company experienced ...

. Shorter and lighter than a stock SD39, these minimized weight per axle.

Original owners

Dash 2 Series

On January 1, 1972, EMD debuted Dash 2 models. No official SD39-2s were built, though the model was catalogued. Some SD39s were rebuilt to Dash 2 specifications, however, and received the SD39-2 designation. Also, BNSF has re-designated some of their SD40-2 locomotives as 'SD39-2s'; it is unknown at this time what mechanical changes have been made to these locomotives.

Dispositions

Some of the SD39 model were subsequently resold to other operators including: Locomotora Fepasa

* FEPASA - 14 SD39-2s numbered 2350-2363; the last seven, 2358–2363, rebuilt as SD39-2M by NRE. * TRANSAP - 4 SD39-3M locomotives rebuilt by

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numbered D2301-D2304.

References

* *Trains Magazine Article December 1968, "A Market Oriented Catalog" by Wallace A. Abbey. The same article appears in Kalmbach's Our GM Scrapbook pages 82–83 subtitle, "Little diesel, big job". SD39 C-C locomotives Diesel-electric locomotives of the United States Railway locomotives introduced in 1968 Freight locomotives Standard gauge locomotives of the United States 5 ft 6 in gauge locomotives {{diesel-loco-stub