EMD "GP40"/"GP40-2"

Last revised: March 11, 2023

By: Adam Burns

Electro-Motivea's GP40 series was the pinnacle of the builder's four-axle locomotives. Manufactured between the mid-1960s and mid-1980s the GP40 came in a wide variety of variants, six altogether, although the original design and "Dash 2" were both the most popular selling nearly 2,500 examples between them.


By the 1960s railroads were beginning to understand the usefulness and efficiency of six-axle, C-C locomotives and as such began to purchase more and more, particularly during the 1970s.

Unfortunately, for EMD, by the time production had wrapped up on the GP40-2 it was losing an alarming amount of market share to General Electric and before the 1980s had ended would lose first place and to this day remains behind GE.

Recently completed Rio Grande GP40-2 #3119 awaits pickup and delivery to its new owner at Blue Island, Illinois in September of 1974. American-Rails.com collection.

In any event, given the relative young age of some GP40s and the fact that thousands were manufactured, many still remain in service on Class Is and can also be found on both short lines and regionals. 

Many have also been heavily modified or rebuilt over the years featuring modern electronics and overhauled prime movers.  As a result, they carry little more than the original carbody with which they left the EMD factory.

Katy GP40 #183, Conrail GP38-2 #8025 and GP38 #7851, and three other MKT units lead a general manifest between Taylor and Temple, Texas, circa 1983. Mike Bledsoe photo. American-Rails.com collection.


The GP40 and GP40-2 production run lasted over twenty years beginning in 1965 and ceasing in 1987 (the GP40 was last produced in 1971).

The units themselves were not that different from GP38s and GP38-2s except that they included some newer technologies; an extra radiator fan, turbocharger stack and an extra 1,000 hp (rated at 3,000 hp over the GP38 series 2,000 hp).

The GP40 also included features already now common on earlier models such as dynamic braking, and an airtight hood that kept out dust, dirt and other particles from reaching internal components.

Rio Grande GP40 #3086, GP35 #3048, and three other units exit tunnel #8 near Plainview, Colorado with an eastbound coal drag as the train descends the Front Range into Denver, circa 1972. American-Rails.com collection.

The "Dash 2" model is distinguished from the original because of its further upgrades which included things like a newer type of traction motor blower duct, a modular electronic cabinet system and bolted battery box access doors.

Essentially, as with all EMD “Dash” models, GP40-2s basically include upgraded electronics and technologies over the original design.

While both the GP40 and GP40-2 offered the same horsepower rating the former was equipped with EMD's model 645E prime mover while the latter featured the 645E3C.

Interestingly, the GP40 offered a little better tractive effort (62,500 pounds starting and 54,700 pounds continuous) than its "Dash 2" counterpart although both were very similar in this regard.

Detroit, Toledo & Ironton GP40-2 #423 at Flat Rock, Michigan; September 1982. American-Rails.com collection.

Also, the GP40 and GP40-2 models were the pinnacle of EMD’s four-axle locomotives in several ways. First, the design was EMD’s most successful second-generation locomotive.

Combined GP40s and GP40-2s sold over 2,300 units with the GP40 selling some 1,200+ units and the GP40-2 slightly less at just over 1,100.

Second, the model effectively ended production of four-axle power as railroads began to order more and more six-axle units because of their added traction and weight distribution.

Later GP50 and GP60 models were produced but were only marginally success compared to the GP40 and early series. Today, virtually all new locomotives ordered are of the C-C, six-axle variety save for switchers or light duty units.

A pair of Baltimore & Ohio GP40's leased to the Santa Fe, circa 1979. Mike Bledsoe photo. American-Rails.com collection.

It should be noted that there were several variants of the GP40 aside from the popular "Dash 2". First was the GP40X. This was constructed using EMD's model 645E prime mover and offered extra horsepower of 3,500.

It was built only between 1977 and 1978 with four railroads purchasing 23 examples of the model; Santa Fe (3800-3809), Southern Pacific (7200-7201, 7230-7231), Southern (7000-7002), and Union Pacific (9000-9005).

The "X" denoted the model as an experimental and the AT&SF and Southern had theirs equipped with Blomberg M trucks while the other lines purchased theirs with HT-B trucks. 

Another variant was the GP40P built for passenger service and purchased by the New Jersey Department of Transportation in 1968 for use by then Central Railroad of Jersey along its commuter lines. 

It was three feet longer than a standard GP40 for an added steam generator and 13 in total were constructed. Another passenger model was built by General Motors Diesel for GO Transit of Toronto between November and December, 1966.

Electro-Motive GP40 #205, named "Carla Marie," is seen here on March 2, 1997. Location not listed. This unit was built as Rock Island #375 in January, 1967. Bryan Copple photo. American-Rails.com collection.

They used an SD40 frame and wide cab design, featuring HEP equipment for passenger service. A total of eight were constructed (numbered 600-607).

There are numerous other GP40 passenger models now in service but these are rebuilds of standard models and were not cataloged directly by EMD or GMD (they include the GP40-2H, GP40PH-2/A/B, GP40FH-2, GP40WH-2, GP40-2W, GP40MC, and GP39H-2). 

Yet another variant was the GP40P-2 built for the Southern Pacific in November, 1974.

This locomotive was 62 feet in length to accommodate a steam generator for use in passenger service and also offered 3,200 horsepower and added tractive effort; 64,000 pounds starting and 54,700 pounds continuous.

Three were built (numbered 3197-3199). Finally, there was the GP40-2W and GP40-2LW, built for Canadian National and GO Transit that included the wide cab commonly used in Canada.

Data Sheet

Entered Production (GP40)11/1965 (New York Central #3036)
Entered Production (GP40X)5/1965 (Demonstrator #433-A)
Entered Production (GP40P)10/1968 (Jersey Central #3671)
Entered Production (GP40-2)4/1972 (Seaboard Coast Line #1636)
Entered Production (GP40P-2)11/1974 (Southern Pacific #3197)
Years Produced (GP40)11/1965 - 12/1971
Years Produced (GP40X)5/1965
Years Produced (GP40P)10/1968
Years Produced (GP40-2)4/1972 - 12/1986
Years Produced (GP40P-2)11/1974
Engine (GP40, GP40P, GP40X)645E
Engine (GP40-2, GP40P-2)645E3C
Engine BuilderGM
Horsepower (GP40, GP40X, GP40P, GP40-2)3000
Horsepower (GP40P-2)3200
Length (GP40, GP40X, GP40-2)59' 2"
Length (GP40P, GP40P-2)62' 8"
Height (Top Of Rail To Top Of Cab)15' 5"
Width (GP40)10' 2 ½"
Width (GP40P, GP40X, GP40-2, GP40P-2)10' 4"
Weight (GP40)245,000 Lbs
Weight (GP40P, GP40P-2)270,000 Lbs
Weight (GP40X)260,000 Lbs
Weight (GP40-2)250,000 Lbs
Fuel Capacity (GP40)1700 - 3600 Gallons
Fuel Capacity (GP40P)1800 Gallons
Fuel Capacity (GP40X, GP40P-2)3200 Gallons
Fuel Capacity (GP40-2)1700 Gallons
Air CompressorGardner-Denver
Air Compressor ModelWBO
Air Brake ManufacturerWestinghouse
Air Brake Schedule26L
Truck TypeBlomberg
Truck Wheelbase9'
Wheel Size40"
Traction Motors (GP40, GP40P, GP40-2)D77 (4), GM
Steam Generator (GP40P, GP40P-2)Vapor Clarkson (800 Lbs/Hr)
Traction Motors (GP40X)D87 (4), GM
Primary Generator (GP40, GP40P, GP40-2, GP40P-2)AR10, GM
Primary Generator (GP40X)AR15, GM
Auxiliary GeneratorDelco (64-72)
MU (Multiple-Unit)Yes
Dynamic BrakesYes
Gear Ratio (GP40, GP40X, GP40P-2)62:15
Gear Ratio (GP40P)61:16
Tractive Effort (Starting)62,500 Lbs at 25% (GP40)
Tractive Effort (Starting)72,000 Lbs at 25% (GP40P)
Tractive Effort (Starting)64,000 Lbs at 25% (GP40X, GP40P-2)
Tractive Effort (Starting)61,000 Lbs at 25% (GP40-2)
Tractive Effort (Continuous)54,700 Lbs at 11.1 mph (GP40, GP40P, GP40-2, GP40P-2)
Tractive Effort (Continuous)54,200 Lbs at 11.1 mph (GP40X)
Top Speed (GP40, GP40X, GP40-2, GP40P-2)65 mph
Top Speed (GP40P)77 mph

Production Rosters


Owner Road Number(s) Quantity Date Built
Atlanta & West Point726-73271967-1970
Atlantic Coast Line915-929151966
Baltimore & Ohio3684-3779, 4000-40641611966-1971
Burlington170-189, 620-639401966-1967
Chesapeake & Ohio3780-3794, 4065-4099501971
De Queen & Eastern RailroadD7, D1221966-1971
Denver & Rio Grande Western3051-3093431966-1971
Detroit, Toledo & Ironton400-40561968
Electro-Motive (Demo)11-26, 2068-2071201969
Florida East Coast401-410101971
Georgia Railroad751-75441967-1968
Illinois Central3000-3074, 3057 (2nd)761966-1970
Louisville & Nashville3000-3029301966-1967
Milwaukee Road153-199, 180 (2nd), 2011, 2027, 2037, 2047-2071, 2055 (2nd)791966-1969
Missouri-Kanas-Texas Railroad (Katy)170-230, 181 (2nd)621966-1969
New York Central3000-31041051965-1967
Norfolk & Western1329-1388601966-1967
Penn Central3105-32741751968-1969
Richmond, Fredericksburg & Potomac121-12771966-1967
Rock Island340-396, 4700-4719771966-1970
Seaboard Air Line600-650511966-1967
Seaboard Coast Line1566-1635701970-1971
Soo Line732-73541967
St. Louis Southwestern Railway (Cotton Belt/SP)7600-760781966
Texas, Oklahoma & Eastern RailroadD13, D1411971
Toledo, Peoria & Western100011969
Western Maryland3795-379951971
Western Pacific3501-3544441966-1971
Western Railway Of Alabama701-70771967-1970


Owner Road Number(s) Quantity Date Built
Santa Fe3800-3809101978
Southern Pacific7200-7201, 7230-723141978
Southern Railway7000-700231978
Union Pacific9000-900561977-1978


Owner Road Number(s) Quantity Date Built
Central Railroad Of New Jersey3671-3683131968


Owner Road Number(s) Quantity Date Built
Alaska Railroad3000-3005, 3007-3015151975-1978
Atlanta & West Point73311974
Baltimore & Ohio1977 (GM50), 4100-4256, 4287-4307, 4308-4311, 4322-4351, 4422-44472391972-1981
Boston & Maine300-317181977
Chesapeake & Ohio4165-4184, 4262-4286, 4372-4421751978-1980
Denver & Rio Grande Western3094-3130371972-1983
Department Of Transportation, Pueblo00311978
Detroit, Toledo & Ironton406-425201972-1979
Florida East Coast411-434241972-1986
Georgia Railroad755-75621972
Kansas City Southern796-79941979-1981
Louisville & Nashville6600-6616171980
Richmond, Fredericksburg & Potomac141-14771972
Seaboard Coast Line1636-1656, 6617-6621261972-1980
Southern Pacific7240-7247, 7608-7627, 7658-7677, 7940-7959681978-1984
St. Louis San Francisco Railway (Frisco)750-774251979
St. Louis Southwestern Railway (Cotton Belt/SP)7248-7273, 7628-7657561979-1984
Texas, Oklahoma & Eastern RailroadD15, D16, D2031973-1974
Western Maryland4257-4261, 4312-4321, 4352-4371291977-1979
Western Pacific3545-3559151979-1980
Western Railway Of Alabama70811974


Owner Road Number(s) Quantity Date Built
Southern Pacific3197-319931974

In this Western Pacific photo, GP40 #3508 rests at the road's engine terminal in Oroville, California during May of 1966. Author's collection.

The models were built between December, 1973 and September, 1975. GO purchased 11 GP40-2Ws (numbered 9808-9814 and 707-710) while CN bought 35 of the model (numbered 9633-9667).

Additionally, CN bought another 233 GP40-2LWs (numbered 9400-9632). 

In any event, GP40s remain as common as railroad spikes out on main lines across the country and you can spot them virtually anywhere as they carry all of the classic EMD features.

The GP40 and GP40-2 models, along with the GP38 and GP38-2, were EMD’s most successful second-generation Geeps and like earlier models fit exactly what railroads were looking for in terms of horsepower while also featuring the manufacturers’ excellence in quality and reliability. 


  • Foster, Gerald. A Field Guide To Trains. New York: Houghton Mifflin, 1996.
  • Marre, Louis A. and Pinkepank, Jerry A. Contemporary Diesel Spotter's Guide, The: A Comprehensive Reference Manual To Locomotives Since 1972.  Milwaukee: Kalmbach Publishing Company, 1989.
  • McDonnell, Greg. Locomotives: The Modern Diesel & Electric Reference, 2nd Edition. Buffalo: Boston Mills Press/Firefly Books, 2015.
  • Solomon, Brian.  EMD Locomotives.  Minneapolis: MBI Publishing Company, 2006.
  • Solomon, Brian.  GE and EMD Locomotives:  The Illustrated History.  Minneapolis:  Voyageur Press, 2014.
  1. Home
  2.  ›
  3. Diesel Locomotives
  4.  ›
  5. EMD GP40

Recent Articles

  1. Cuyahoga Valley Scenic Railroad: Overview, Roster, Photos

    Mar 27, 23 07:21 PM

    The Cuyahoga Valley Scenic Railroad is one of the most popular tourist trains in Ohio offering guests scenic views of the Cuyahoga Valley National Park and lots of excursion options during the year.

    Read More

  2. Wisconsin Great Northern Railroad: Roster & Overview

    Mar 27, 23 07:20 PM

    Wisconsin Great Northern Railroad's Spooner Excursion runs between between Spooner and Springbrook, Wisconsin. The company has steadily grown their tourist line since beginning in 1996 and today also…

    Read More

  3. Whitewater Valley Railroad: Roster, Events, History

    Mar 27, 23 07:19 PM

    The Whitewater Valley Railroad is a tourist line located in southern Indiana operating a short stretch of former New York Central trackage since 1984.

    Read More

  4. Midwest Central Railroad (Mt. Pleasant, IA): Roster & Overview

    Mar 27, 23 07:15 PM

    The Midwest Central Railroad dates to the 1950s and only features one mile of track to operate. However, they offer an entire fleet of operating steam locomotives to see!

    Read More

  5. Huckleberry Railroad (Michigan): Trains, Overview, Photos

    Mar 27, 23 07:14 PM

    The Huckleberry Railroad is a tourist attraction that is part of the Crossroads Village & Huckleberry Railroad Park located in Flint, Michigan featuring several operating steam locomotives.

    Read More


Wes Barris's SteamLocomotive.com is simply the best web resource on the study of steam locomotives. 

It is difficult to truly articulate just how much material can be found at this website. 

It is quite staggering and a must visit!