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The SD45 is a six-axle road switcher diesel-electric locomotive built by General Motors Electro-Motive Division between 1965–1971. It had an EMD 645E3 twenty-cylinder engine generating 3,600 hp (2,680 kW) on the same frame as the EMD SD38, EMD SD39, EMD SD40, and EMD SDP40. As of 2017, most SD45s have been retired, scrapped, or rebuilt to SD40-2 standards.

Hustle Muscle Osceola.jpg
First production SD45 Great Northern 400 in service at the Minnesota Transportation Museum
Type and origin
Power typeDiesel
BuilderGeneral Motors Electro-Motive Division (EMD)
Build dateDec. 1965 – Dec. 1971
Total produced1,260
Gauge4 ft 8 12 in (1,435 mm) standard gauge
Length65 feet 8 inches (20.02 m); 65 feet 9 12 inches (20.053 m) on some units starting early 1968.
Loco weight368,000 pounds (167,000 kg)
Prime moverEMD 645E3
Engine typeV20 diesel
Performance figures
Maximum speed71 miles per hour (114 km/h)
Power output3,600 hp (2,680 kW)
Tractive effortStarting: 92,000 lbf (410 kN)
Continuous: 82,100 lbf (365 kN) @ 11 mph (18 km/h)



1,260 were built for American railroads before the SD45-2 replaced it in 1972, along with the related SD45T-2 'Tunnel Motor'.

SD45s had several teething problems. Reliability was not as high as anticipated; the twenty-cylinder prime mover was prone to crankshaft failure from engine block flex. Though it produced 600 horsepower (450 kW) more than the 16-645E3 in the SD40, some railroads felt the extra horsepower wasn't worth it, even after EMD strengthened the block to eliminate crankshaft failures. At low speeds, when tractive effort was adhesion-limited, the SD45 provided no advantage over the SD40.

Buyers included the Burlington Northern, Southern Pacific, Santa Fe, Pennsylvania Railroad, the Great Northern Railway, Union Pacific and the Northern Pacific Railway. (Contrary to enthusiast legend[according to whom?] the SD45 was not a "fuel guzzler." It produced marginally more power per unit of fuel than its 3,000 hp (2,240 kW) counterpart, the SD40. It did consume more fuel at idle than the 16 cylinder prime mover in the SD40, and at the time US railroads typically left a locomotive idling when not in use.) Many SD45s still exist, some rebuilt with sixteen-cylinder 645s for lease companies. SD45s and SD45-2s owned by Montana Rail Link retain their 20-cylinder prime movers. Wisconsin Central used to roster a large fleet of SD45s, but its sale to CN has resulted in the retirement of the entire fleet, with mass scrappings. Montana Rail Link is also starting to sell some for scrap.



  1. ^ Foster 1996, p. 58
  2. ^ Solomon 2014, p. 277
  3. ^ | Minnesota Railroads
  4. ^ Glischinski, Steve (15 September 2015). "NP SD45 appears on a photo freight in Minnesota". Trains. Retrieved 16 September 2015. (subscription required)
  5. ^ "Seaboard Coast Line SD45 being restored for museum". Trains. 9 September 2015. Retrieved 10 September 2015. (subscription required)


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