EMD "GP7" Locomotives

Last revised: March 11, 2023

By: Adam Burns

The Electro-Motive  GP7 series was built for both freight and passenger use and would find immense success, even eclipsing its predecessor models to become one of the most success diesel locomotive designs ever built.

The “covered wagons” (slang for the E and F series) would signal the beginning of the end for steam and in just twenty years following the first EA model produced in the mid 1930s, steam would all but disappear from main line railroading (the introduction of GP7 was, perhaps, the final nail in the proverbial coffin for steam).

A year before the GP7's introduction, EMD had unveiled the BL2 model that was intended to be its grand entrance into the road switcher market and compete with Baldwin, Fairbanks Morse, and the American Locomotive Company (Alco) in particular, which had been manufacturing the model for nearly a decade.


Rio Grande GP7 #5104 leads a string of livestock and boxcars southbound along U.S. 285 outside of Alamosa, Colorado during the 1950s. American-Rails.com collection.


However, the BL2 still lacked essential design characteristics dooming its success. EMD learned from this mistake and sales exploded with the GP7, which quickly surpassed its competition.

The locomotive was so reliable and well built that many remain in service with short lines today.  As mentioned, EMD's entrance into the road switcher market began with the BL2 design of 1948.

The company was frustrated that it was not only far behind the other builders in releasing a similar model but also that Alco, at the time, controlled the road switcher market with its "Road Switcher", RS, series.

Up until that time the company was offering railroads two different models, the RS1 and RS2 that had sold an astonishing 1,200 examples in just eight years. While only moderately powered the RS1 and RS2 offered unparalleled flexibility for train crews with its thin long hood and wide cab.

Illinois Central GP7 #8900 works local service at Graymont, Illinois on February 19, 1958. Today, few traces of this line remain. Author's collection.

BL2 Failures

This, in turn, allowed for walkways down the length of the locomotive, and even to the front where a short hood was located.

Additionally, with a semi-streamlined carbody and that short, lead hood Alco's road switchers were ideal for limited passenger service as well.

While both Baldwin and FM offered similar designs like the DRS-4-4-1500 and H15-44, none were as successful as Alco's early lines.

As such, EMD took inspiration from this as well as the failures of its BL2. Spearheading the redesign was once again, EMD's chief engineer Richard "Dick" Dilworth who was instrumental in the development of the phenomenally successful FT of 1939.

Realizing that they already had a reliable and practical locomotive on their hands and simply needed to offer railroads a carbody that was functional Dilworth stripped down the BL2 and started from scratch.

Rock Island GP7 #1278 lays over at the small engine house in Peoria, Illinois, circa 1955. American-Rails.com collection.

He replaced the full length hood with a narrower design and off-set the cab, allowing for a short lead hood. The locomotive was not quite as beveled as the road switchers offered by Alco, Baldwin, and FM.

However, it carried its own stylish appearance with flush lines and tapering at each end. The roof line was likewise clean where it was flush with the cab, unlike in Alco's and Baldwin's models but similar to FM's.

Dubbed the "General Purpose" series or Geep for short to reflect the locomotive's duties as a road switcher the first was named the GP7 and cataloged in October, 1949.

The number "7" was chosen as both the E7 and F7 cab units, as well as the switcher model SW7 were all in production at that time.

Rio Grande GP7 #5108 is seen here at work in Pueblo, Colorado circa 1970. Robert Eastwood, Jr. photo. American-Rails.com collection.

The GP7 carried all of the features that made EMD so highly regarded with its ease of maintenance and nice design features.

The locomotive had an added incentive in that along with being able to handle practically any type of freight service with its 1,500 horsepower rating, the GP7's overall carbody design was also attractive enough to be used in many types of passenger service, which is fascinating in the sense that the the model really offered no type of streamlining.

It was thanks to EMD's styling department headed then by John Markestein, who along with Dilworth helped create the now-classic look of the GP7.

Through 1954 the model sold an astounding 2,700+ units and is widely credited with completing main line dieselization, relegating most remaining steam locomotives to branch line, yard and short line work (an exception would be the Norfolk & Western, which held out on scrapping its steam fleet until the late 1950s).

Santa Fe GP7 #2758 and a CF7 in Temple, Texas, circa 1980. Mike Bledsoe photo. American-Rails.com collection.

As mentioned above the GP7 carried a horsepower rating of 1,500, which again was not uncommon with among the models being offered by Alco, Baldwin, and FM.

It used EMD's standard prime mover of the time, 16-cylinder model 567B and featured components built almost entirely by General Motors, which was standard for virtually all of its models.

These included things like the main generator (model D12), traction motors (model D27B), and alternator (model D14). However, just like with the other manufactures it outsourced air brakes to Westinghouse with the compressor provided by Gardner-Denver.

With a tractive effort of 65,000 pounds starting and 40,000 pounds continuous these ratings could not quite match Fairbanks Morse or Baldwin but their models did not offer the reliability of EMD.

It's the early Erie Lackawanna era as a group of former Erie Railroad GP7's layover between assignments in March, 1964. Photographer and location not listed on slide. Author's collection.


EMD manufactured four demonstrators; #100, #200, #300, and #525 to tour the country in an elegant blue and silver livery. For railroads, it was just what they were hoping for; practicality for use by train crews with the EMD reliability that they expected.

2765823592834723762752786892307.jpgMissouri Pacific GP7 #1690 works local service at Austin, Texas on December 1, 1980. Mike Bledsoe photo. American-Rails.com collection.

As such, sales quickly took off. It should be noted that there was one request for GP7Bs from the Santa Fe who purchased five in the early spring of 1953, numbered 2788A-2792A.

Also, the model was most commonly built with the high hood but some railroads requested a lowered version in the later standard cab design, which included front windshields (GP7s would also be rebuilt with shortened hoods).

Still commonly found today on several regionals and short lines the GP7 is the classic image of the road switcher with its high, short hood and cab set off to one end leaving for a long hood trailing.

Data Sheet

Entered Production10/1949 (Demonstrator #922)
Years Produced10/1949 - 5/1954 (4/1953 for GP7B)
Engine BuilderGM
Length55' 11"
Height (Top Of Rail To Top Of Cab)14' 6"
Width10' 3"
Weight246,000 Lbs
Fuel Capacity800 Gallons
Air CompressorGardner-Denver
Air Compressor ModelWBO
Air Brake ManufacturerWestinghouse
Air Brake Schedule24L
Truck TypeBlomberg
Truck Wheelbase9'
Wheel Size40"
Traction MotorsD27B (4), GM
Primary GeneratorD12, GM
Auxiliary GeneratorDelco (64-72)
Steam Generator (Optional)Vapor-Clarkson (Model 4625)
MU (Multiple-Unit)Yes
Dynamic BrakesYes
Gear Ratio62:15
Tractive Effort (Starting)65,000 Lbs at 25%
Tractive Effort (Continuous)40,000 Lbs at 9.3 mph
Top Speed65 mph

Production Roster

Owner Road Number(s) Quantity Date Built
Abredeen & Rockfish Railroad20511951
Alabama Great Southern (Southern)6540-654451950
Atlanta & St. Andrews Bay Railway501-50221952
Atlanta & West Point Railroad571-57551950-1952
Atlantic & East Carolina Railway50111951
Atlantic Coast Line100-2531541950-1951
Baltimore & Ohio720-731, 740-746, 910-922, 6405331953
Bangor & Aroostook560-575161950
Belt Railway Of Chicago470-47781951-1952
Boston & Maine1555-1577231950-1953
Butte, Anaconda & Pacific Railway101-10331952-1953
Central Of Georgia106-107, 120-132151950-1951
Central Railroad Of New Jersey1520-1532131952
Charleston & Western Carolina Railway200-220211950-1951
Chesapeake & Ohio5700-5719, 5710-5714 (2nd), 5739-5797, 5800-59001851950-1953
Cincinnati, New Orleans & Texas Pacific (Southern)6200-6205, 6240-6244111950- 1953
Chicago, St. Paul, Minneapolis & Omaha (C&NW)151-161111951-1952
Chicago & Eastern Illinois203-232301950-1951
Chicago & North Western1518-1550, 1556-1559, 1562-1599, 1601-1603, 1625-16591131949- 1953
Chicago Great Western120-12121951
Clinchfield Railroad900-911121950
Colorado & Wyoming Railway103-10421951
Colorado Fuel & Iron Company101-10221951
Columbia, Newberry & Laurens Railroad100-10451950-1951
Denver & Rio Grande Western5101-5104, 5104 (2nd), 5105-5113141950-1952
Detroit, Toledo & Ironton950-973241951-1953
Detroit & Toledo Short Line41-50101951-1953
Electro-Motive (Demo)200, 300, 525, 922 (renumbered 100)41949-1953
Erie Railroad1200-1246, 1400-1404521950-1952
Florida East Coast607-621151952
Georgia & Florida Railway701-70661950
Georgia Railroad1021-1036161950-1953
Georgia Southern & Florida (Southern)8210-821341950
Great Northern600-655561950-1953
Illinois Central8800-8801, 8850-8851, 8900-8911, 8950-8957, 8968-8981, 8958-8967481950- 1953
Illinois Terminal1600-160561953
International-Great Northern Railroad (MP)4121-4123, 4153-4158, 4197-4202, 4254-4255, 4287- 4297, 4325291950-1954
Kansas, Oklahoma & Gulf Railway801-80991952-1953
Kansas City Southern155-16281953
Louisiana & Arkansas Railway (KCS)150-15451951
Louisville & Nashville400-440, 500-505, 501-502 (2nd), 507-514, 508 (2nd), 550-552611951-1953
Maine Central561-580, 566-569 (2nd)241950-1953
Meridian & Bigbee Railroad111952
Midland Valley Railroad151-15441953
Missouri-Kansas-Texas Railroad (Katy)1510-1529, 1761-1764241951-1952
Missouri Pacific4124-4152, 4166-4194, 4208-4248, 4256-4283, 4299-43221511950-1953
Nashville, Chattanooga & St. Louis Railway700-731, 750-754371950-1952
New York Central5600-5611, 5626-5675, 5686-5712, 5738-58171691950-1953
Nickel Plate Road400-447481951-1953
Northern Pacific550-569201950-1953
Pennsylvania8500-8512, 8545-8587 8797-8806661952
Peoria & Eastern Railway (NYC)5612-5625141950
Phelps Dodge Corporation1-2, 7-8, 27-2971952-1953
Pittsburgh & Lake Erie (NYC)5676-5685, 5713-5737351951-1952
Portland Terminal Company (Maine)108111950
Reading600-636, 660-666441952-1953
Richmond, Fredericksburg & Potomac101-10441950-1953
Rock Island430-441, 1200-1237, 1250-1299, 1294 (2nd), 1300-1311, 1308 (2nd)1131950-1953
Santa Fe99, 2650-28932451950-1953
Santa Fe2788A-2792A (GP7B)51953
Seaboard Air Line1700-18221231950-1952
Soo Line375-378, 381-38371950-1952
Southern Railway2063-2077, 2156-2197571951-1953
St. Louis, Brownsville & Mexico (MP)4116-4120, 4159-4165, 4203-4207, 4249-4253, 4284- 4286, 4298, 4323-4324271950-1954
St. Louis San Francisco Railway (Frisco)500-549, 555-632, 615 (2nd)1281950-1952
St. Louis Southwestern Railway (Cotton Belt/SP)32011950
Tennessee, Alabama & Georgia Railway (TAG)707-70931951
Texas-Mexican Railway (Tex-Mex)850-85231950-1951
Texas & Pacific Railway (MP)1110-1130211950-1952
Toledo, Peoria & Western Railway102-10321952
U.S. Army1821-1840201951
Union Pacific700-729301953
Wabash Railroad450-483, 454-458 (2nd)391950-1953
Western Maryland20-2341950
Western Pacific701-713131952-1953
Western Railway Of Alabama521-52661950-1953

This slide had no information. I presume it was perhaps taken in early October, 1963 along with the others in this bunch. The former Lackawanna GP7 (#960) has been reassigned its Erie Lackawanna number (#1279). Also note the trailing RS3 (another former DL&W unit). Author's collection.

Not surprisingly, with the railroad’s love for the locomotive it was given a nickname that is now synonymous with the GP series; using the model’s initials, “GP,” the locomotives became affectionately known as Geeps (pronounced “Jeeps”).

The GP7 was, however, only the beginning of the series and later four-axle, as well as six-axle models would follow. Because of the GP7s lightweight but strong pulling power it was purchased by not only Class Is but also smaller lines. 

Additionally, with EMD's Canadian division, General Motors Diesel of Ontario established in 1949 the company also sold 112 examples to the Algoma Central & Hudson Bay, Canadian National, Canadian Pacific, Chesapeake & Ohio (for its southern Ontario lines), Quebec North Shore & Labrador, Toronto, Hamilton & Buffalo, and Wabash.  


  • Foster, Gerald. A Field Guide To Trains. New York: Houghton Mifflin, 1996.
  • Hayden, Bob. Diesel Locomotives: Cyclopedia, Volume 2 (Model Railroader). Milwaukee: Kalmbach Publishing Company, 1980.
  • Marre, Louis A. Diesel Locomotives: The First 50 Years, A Guide To Diesels Built Before 1972.  Milwaukee: Kalmbach Publishing Company, 1995.
  • Pinkepank, Jerry A. Diesel Spotter's Guide.  Milwaukee: Kalmbach Publishing Company, 1967.
  • Solomon, Brian.  EMD Locomotives.  Minneapolis: MBI Publishing Company, 2006.
  • Solomon, Brian.  GE and EMD Locomotives:  The Illustrated History.  Minneapolis:  Voyageur Press, 2014.
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