The EMD SD40 is a model of 6-axle diesel-electric locomotive built by General Motors Electro-Motive Division between January 1966 and August 1972. 1,268 locomotives were built between 1966 and 1972. In 1972, an improved version with new electronics was developed and marketed as a new locomotive, the SD40-2.
Design
Like its predecessor in EMD's catalog, the SD35, the SD40 is a high-horsepower, six-axle freight locomotive. The SD40 is a member of EMD's long-running Special Duty class of locomotives, which all are built with 6 axles.
In 1966, EMD updated its locomotive catalog with entirely new models, all powered by the new 645 diesel engine. These included six-axle models SD38, SD40, SDP40 and SD45. All shared standardized components, including the frame, cab, generator, trucks, traction motors, and air brakes. The primary difference was the power output: SD38 = 2,000 hp (1,490 kW) from a non-turbocharged V16, SD40 = 3,000 hp (2,240 kW) from a turbocharged V16, and SD45 = 3,600 hp (2,680 kW) from a turbocharged V20.
Original owners
856 examples of this locomotive model were built for American railroads, 330 were built for Canadian railroads, 72 were built for Mexican railroads, 6 were built for the Guinea-Boke Project, and 4 SD40Ms riding on 5 ft 3 in (1,600 mm) gauge trucks were exported to Brazil. They were manufactured at McCook, Illinois.
Phases are as listed by Robert Sarberenyi. [citation needed]
Derivatives and Experimental
GMD SD40 KCSM 3029 in Caltzonzin StationGTW/CN #5945, a former GMD-built CN SD40, rebuilt to SD40-3 standards.Last Mountain Railway SD40-3 at Aylesbury, Saskatchewan
The very first test bed SD40, EMD 434, constructed on an SD35 frame in July 1964 was in active service until retired by Canadian National Railway in March 2009 and donated to the Monticello Railway Museum in July 2009, albeit having been upgraded to an "SD40-2R", as Illinois Central 6071.
18 customized SD40s were built for the Illinois Central Railroad as model SD40A, using the longer SDP45 frame, which allowed for a larger 5,000 gallon fuel tank.
The SD40 was succeeded by an upgraded Dash 2 version called the SD40-2.
SD40 rebuilds
After having been succeeded by the more modern SD40-2, a large number of SD40 have been upgraded with more modern equipment. The main difference between rebuilt SD40 and genuine SD40-2 is that the latter use a longer frame and has longer front and rear porches, while the rebuilt SD40 have a shorter frame.
A common product of rebuilding SD40s, and sometimes SD40-2s, is an SD40-3. The major addition denotes that the rebuilt unit or units as an SD40-3 is the addition of a micro-processor, and sometimes other modern components. The usual reasons for installing a micro-processor are improved traction control, and better fuel economy (via better injection control). Also, electronic control over braking systems (independent and automatic). This may include some SD39, SD45 and SD45-2 rebuilt to SD40-2 standards.
The SD40R is a rebuilt of all the Southern Pacific's SD40 between 1980 and 1981.[1]
The SD40M-2 was a rebuild done by Morrison Knudsen for two railroads, the Southern Pacific, using 97 SD45s, 30 SD40s and 6 SDP45s,[2] and the Canadian Pacific, using another three SD40s and seven SD45s.[3][4]
Canadian Pacific SD40 #5500 is preserved at the Revelstoke Railway Museum in Revelstoke, British Columbia. It was CP's first SD40, built in 1966 at GMD's London plant and was retired in 2001. The unit was donated to the museum in 2007. Plans are being made to restore the locomotive to its original grey/tuscan red paint scheme, known as the Canadian Pacific "Script"[7]
Norfolk Southern #1580 is preserved by the Roanoke Chapter NRHS. It was donated by Norfolk Southern in 2024. It is presently being restored to its N&W "Pevler Blue" paint scheme.[10]