Former BNSF 1685 high hood GP9 sitting in the Prairie Dog Central Yard. This was the last GP9 on the BNSF roster.

(Taylorover9002, CC BY-SA 4.0 <>, via Wikimedia Commons)


GM EMD logo.


The EMD GP9 is a four-axle diesel-electric locomotive built by General Motors' Electro-Motive Division between 1954 and 1959. The GP9 succeeded the GP7 as the second model of EMD's General Purpose (GP) line, incorporating a new sixteen-cylinder engine which generated 1,750 horsepower (1.30 MW). This locomotive type was offered both with and without control cabs; locomotives built without control cabs were called GP9B locomotives.

EMD constructed 3,626 GP9s, including 165 GP9Bs. An additional 646 GP9s were built by General Motors Diesel, EMD's Canadian subsidiary, for a total of 4,257 GP9s produced when Canadian production ended in 1963. The GP9 was succeeded by the similar but slightly more powerful GP18.


An EMD GP9 equipped with dynamic brakes on the Shenandoah Valley Railroad in Staunton, Virginia. (William Grimes, Public domain, via Wikimedia Commons)

Former Northern Pacific 245, operational on the North Shore Scenic Railroad in Duluth, Minnesota. (Keon McGarvey, CC BY-SA 4.0 <>, via Wikimedia Commons)

An MBTA GP9 locomotive making a non-revenue move into South Station in Boston, Massachusetts. Now on static display at the Illinois Railway Museum as of September 2014. (Adam E. Moreira., CC BY-SA 3.0 <>, via Wikimedia Commons)


A modified EMD GP9 of the Seminole Gulf Railway, Fort Myers, Florida. (Harvey Henkelmann, Attribution, via Wikimedia Commons)

South Branch Valley Railroad engine 6240, a 1957 EMD GP9. (PRR90 at English Wikipedia, CC BY-SA 3.0 <>, via Wikimedia Commons)


GP9 on the Heber Valley Railroad. (Jacob Lyman, CC BY-SA 4.0 <>, via Wikimedia Commons)

Great Western RY GP9 296. Built in 1954 for the Union Pacific. (Don O'Brien from Piketon, Ohio, United States, CC BY 2.0 <>, via Wikimedia Commons)

City of Prineville 1837, a GP9, at the Prineville Yard. (Tequask, CC BY-SA 4.0 <>, via Wikimedia Commons)

Design and Production

EMD designed the GP9 as an improved version of the GP7, with an increase in power from 1,500 hp to 1,750 hp, and a change in prime mover to the latest version of the 567 engine, the 567C. Externally, the GP9 strongly resembled its predecessor. Most were built with high short hoods, but the Southern Pacific ordered a number with low short hoods for improved crew visibility.

EMD built GP9s at its LaGrange, Illinois facility until 1959, when American production was ended in favor of the GP18. GMD production in Canada continued until August 1963, when the final GP9 was produced.


A Canadian Pacific Railway EMD GP20C-ECO, the product of a GP9 rebuild.

(J73364, CC BY-SA 4.0 <>, via Wikimedia Commons)



There were 40 GP9M units built that are included in the 3,441 units built for United States railroads. A GP9M was built with parts from another older EMD locomotive, either an F unit or a damaged GP7. The use of parts from these older locomotives caused the GP9Ms to have a lower power rating than a GP9. This would be either 1,350 horsepower (1.01 MW) if the donor locomotive was an FT/F2 or 1,500 horsepower (1.12 MW) from F3/F7/GP7 locomotives.

Many rebuilt GP9s remain in service today with shortline railroads and industrial operators. Some remain in rebuilt form on some major Class I railroads, as switcher locomotives although most Class 1 railroads stopped using these locomotives by the 1980s. Canadian National still had 29 GP9RM locomotives in operation, as of 2022. Canadian Pacific had many GP9u locomotives in operation; however, they were all retired in 2015.

Several GP9s were rebuilt with a 1,500 horsepower (1.12 MW) CAT 3512 and re-classified as GP15C.

The Illinois Central Railroad rebuilt some of its GP9s with their front (short) hood reduced in height for improved crew visibility. The IC designated these rebuilt locomotives GP10.

EMD has rebuilt and continues to rebuild GP9s into what it calls the GP20C-ECO, which is repowered with an EMD 8-710-G3A engine in place of the original 567 prime mover.


Baltimore & Ohio GP9 No. 6604. Photo by The Potomac Eagle, David W. Corbitt.

(© 1996 Mary Jayne's Railroad Specialties, Inc., Fair Use, Title 17, Section 107, via W. Lenheim Collection)



At least 23 GP9 locomotives have been preserved at various railroad museums, as "park engines", and as excursion engines according to The Diesel Shop:

B&O 6607, originally numbered 3414, is at the B&O Railroad Museum, Baltimore, Maryland, in operating condition.
Southern Pacific 3194, a GP9R rebuild built as Texas and New Orleans 281, is at the Golden Gate RR Museum, California. It is in operating condition.
Northern Pacific 245 preserved at the Lake Superior Railroad Museum in Duluth, currently painted as North Shore Scenic Railroad 245. 


Southern Pacific EMD GP9E 3879 at Roseburg, Oregon, August, 1985. Photographer: Craig Garver.

(Craig Garver, Public domain,


EMD GP9 Type and origin

Power type: Diesel-electric
Builder: General Motors Electro-Motive Division (EMD); General Motors Diesel (GMD)
Build date: 1954 – 1963
Total produced: 4,092 (and 165 B units)
​• AAR B-B
Gauge: 4 ft 8+1⁄2 in (1,435 mm) standard gauge; 5 ft 3 in (1,600 mm) (Brazil)
Trucks: EMD Blomberg B (Flexicoil on some CN units)
Wheel diameter: 40 in (1.016 m)
Minimum curve: 21° (273 ft (83.21 m) radius)
Wheelbase: 40 ft (12.19 m)
Length: 56 ft 2 in (17.12 m)
Width: 10 ft 3+1⁄2 in (3.14 m)
Height: 15 ft 1⁄2 in (4.58 m)
Locomotive weight: 259,500 lb (117,700 kg)
Fuel capacity: 1,100 US gal (4,200 L; 920 imp gal)
Prime mover: EMD 16-567C
RPM range: 835 max
Engine type: V16 Two-stroke diesel
Aspiration: Roots blower
Displacement: 9,072 cu in (148.66 L)
Generator: EMD D-12-B
Traction motors: (4) EMD D-37-B
Cylinders: 16
Cylinder size: 8+1⁄2 in × 10 in (216 mm × 254 mm)
Performance figures
Maximum speed: 65 mph (105 km/h)
Power output: 1,750 hp (1.30 MW)
Tractive effort: 64,750 lbf (288.0 kN)
Locale: North America, South America