Great Northern 400 in service at the Minnesota Transportation Museum.

(Keon McGarvey, CC BY-SA 4.0 <>, via Wikimedia Commons)


EMD logo.


The SD45 is a six-axle diesel-electric locomotive class built by General Motors Electro-Motive Division between 1965 and 1971. It has an EMD 645E3 twenty-cylinder engine generating 3,600 hp (2,680 kW) on the same frame as the SD38, SD39, SD40, and SDP40. As of 2023, most SD45s have been retired, scrapped or rebuilt to SD40-2 standards.



A total of 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. 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 most being sold for scrap. Montana Rail Link is also starting to sell some for scrap.


Accidents and incidents

February 20, 1989, Southern Pacific SD45R locomotive No. 7502 was involved in a wreck that derailed 48-cars of an 82-car train and three of these cars had contained residue from chlorine, phosphoric acid and hydrocarbons.
On May 12, 1989, Southern Pacific SD45R locomotives No. 7551 (formerly No. 8985) and No. 7549 (formerly No. 9038) were both destroyed in the 1989 Cajon Pass Runaway when they crashed along Duffy Street in San Bernardino, California.



The Atchison, Topeka and Santa Fe Railway has rebuilt 115 units into what had become the EMD SD45u. They were all renumbered as 5300-5483 between 1979 and 1989.

The Southern Pacific Transportation Company had rebuilt a total of 167 EMD SD45 units into EMD SD45R diesel locomotives at their own Sacramento Shops under the Southern Pacific's M-99 rebuild program and renumbered their units as 7400 through 7566. Most of them in their SD45 form were classified by the Southern Pacific as EF636-1, EF636-2, EF636-3, EF636-4, EF636-5 and EF636-6, but when they were all rebuilt under the Southern Pacific's M-99 rebuild program, they were classified as EF636LR-1, EF636R-2 and EF636LR-3.


Original owners

Railroad Quantity Road Numbers
Electro-Motive Diesel (demonstrators) 4 4351-4354
Atchison, Topeka and Santa Fe Railway 125 1800-1889, 5590-5624. 1884 rebuilt to SD45u renumbered to 5300-5483 between 1979 and 1989.
Atlantic Coast Line Railroad 10 1024-1033
Burlington Northern Railroad 96 6472-6567
Chicago, Burlington and Quincy Railroad 15 516-530
Chicago, Milwaukee, St. Paul and Pacific Railroad 10 4000-4009
Chicago and North Western Railway 61 901-920, 937-977
Colorado and Southern Railway 7 868-874
Denver and Rio Grande Western Railroad 26 5315-5340
Erie Lackawanna Railway 34 3601-3634
Great Northern Railway 27 400-426
Norfolk and Western Railway 115 1700-1814
Northern Pacific Railway 30 3600-3629
Penn Central Transportation Company 5 6235-6239
Pennsylvania Railroad 130 6105-6234
Reading Company 5 7600-7604
Seaboard Coast Line Railroad 35 2010-2044
Southern Railway 70 3100-3169
Southern Pacific Transportation Company 317 8800-8963, 8982–9051, 9069-9151 most rebuilt to SD45R locomotives. 7551 and 7549 destroyed 1989 Cajon Pass Runaway and scrapped.
St. Louis-San Francisco Railway 49 900-948
St. Louis Southwestern Railway 39 8964-8981, 9052–9068, 9152-9155
Union Pacific Railroad 50 3600-3649
Totals 1,260

NP 3617, a preserved SD45 in Minnesota.

(Keon McGarvey, CC BY-SA 4.0 <>, via Wikimedia Commons)



  • Erie Lackawanna No. 3607 is preserved at the St. Louis National Museum of Transportation. Restored to EL colors, this unit is a static display.
  • Great Northern 400, named "Hustle Muscle", was the first production SD45. It is preserved by the Great Northern Railway Historical Society, based out of Saint Paul, Minnesota. It was in active service on the Minnesota Transportation Museum's Osceola and St. Croix Valley Railway until it suffered a crankshaft failure in its original 20-645E3 engine, requiring a replacement engine to be installed. BNSF Railway overhauled a 20-645E3 engine from a retired ex-ATSF SD45-2 and donated and installed the new engine in January 2019.
  • Kansas City Southern No. 1200 is at the Rail Museum of Heroica Matamoros in Matamoros, Mexico on static display.
  • Norfolk and Western No. 1776, a high-hood unit, is a static display at the Virginia Museum of Transportation.
  • Northern Pacific 3617 is preserved at the Lake Superior Railroad Museum. It has been restored to active service.
  • Seaboard Coast Line No. 2024 is preserved at the Southern Appalachia Railway Museum in Oak Ridge, Tennessee, and is currently painted in the Clinchfield Railroad scheme as of December 2017.
  • Southern Pacific 7457 is a static display at the Utah State Railroad Museum in Ogden, Utah.
  • Wisconsin Central No. 7525 is at the Illinois Railway Museum and is operable. It is one of two WC SD45 units to be painted in an Operation Lifesaver scheme.



Type and origin
Power type: Diesel
Builder: General Motors Electro-Motive Division (EMD)
Model: SD45
Build date: Dec. 1965 – Dec. 1971
Total produced: 1,260
Configuration:  AAR C-C
Gauge: 4 ft 8+1⁄2 in (1,435 mm) standard gauge
Length: 65 feet 8 inches (20.02 m); 65 feet 9+1⁄2 inches (20.053 m) on some units starting early 1968.
Locomotive weight: 368,000 pounds (167,000 kg)
Prime mover: EMD 645
Engine type: V20 diesel
Generator: AR10B
Cylinders: 20
Performance figures
Maximum speed: 71 miles per hour (114 km/h)
Power output: 3,600 hp (2,680 kW)
Tractive effort starting: 92,000 lbf (410 kN)
Tractive effort continuous: 82,100 lbf (365 kN) @ 11 mph (18 km/h)