The EMD GP7 is a four-axle (B-B) diesel-electric locomotive built by General Motors Electro-Motive Division and General Motors Diesel between October 1949 and May 1954.Pinkepank, Jerry A. (1973) pp. 53
The GP7 was the first EMD road locomotive to use a hood unit design instead of a car-body design. This proved to be more efficient than the car body design as the hood unit cost less to build, was cheaper and easier to maintain, and had much better front and rear visibility for switching. Power was provided by an EMD 567B 16-cylinder engine which generated .The History of EMD Diesel Engines The GP7 was offered both with and without control cabs, and those built without control cabs were called a GP7B. Five GP7B's were built between March and April 1953.
Of the 2,734 GP7's built, 2,620 were for American railroads (including 5 GP7B units built for the Atchison, Topeka and Santa Fe Railway), 112 were built for Canadian railroads, and 2 were built for Mexican railroads.
This was the first model in EMD's GP (General Purpose) series of locomotives. Concurrently, EMD offered a six-axle (C-C) SD (Special Duty) locomotive, the SD7. The GP7 was replaced by the GP9 model in GM-EMD's GP sequence.
History ALCO, Fairbanks-Morse, and Baldwin had all introduced road switchers before EMD, whose first attempt at the road-switcher, the BL2 was unsuccessful in the market, selling only 58 units in the 14 months it was in production.Pinkepank, Jerry A. (1973) p. 51 Its replacement, the GP7, swapped the truss-framed stressed car body for an un-stressed body on a frame made from flat, formed and rolled structural steel members and steel forgings welded into a single structure (a "weldment"), a basic design which is still being employed today. In heavy service, the GP7’s frame would bow and sag over time. This defect was corrected in later models.
The GP7 proved very popular, and EMD was barely able to meet demand, even after opening a second assembly plant at Cleveland, Ohio. Later, locomotives in EMD's GP-series came to be nicknamed ‘Geeps’. Many GP7s both high and short-hood can still be found in service today on shortline railroads and industrial operators. Although most Class 1 roads stopped using these locomotives by the 1980s some remain in rebuilt form on some major Class I railroads, as switcher locomotives. The "GP" designation stood for "general purpose", while the "7" had no meaning other than matching the EMD F7 cab unit then in production.
Identification The GP7, GP9 and GP18 locomotives share a similar car-body that evolved over time. Most GP7s had three sets of ventilation grills under the cab (where the GP9 only had one), and two pair of grills at the end of the long hood (where only the pair nearest the end was retained on the GP9). However, some late GP7s were built with car-bodies that were identical to early GP9s. Early GP7s had a solid skirt above the fuel tank, while late GP7s and early GP9s had access holes in the skirt (see photo of Illinois Terminal 1605, top left). Many railroads later removed most of the skirt to improve access and inspection.
Locomotives could be built with the engineer’s control stand installed for either the long hood, or the short hood designated as the front. Two control stands for either direction running was also an option, but one end would still be designated as the front for maintenance purposes. The GP7 was also available with or without dynamic brakes, and a steam generator installed in the short hood was also an option. In the latter case, the fuel tank was divided, with half for diesel fuel, and half for boiler water. One option available for locomotives without dynamic brakes, was to remove the two NP Railway diesel diagram, NP 550–551 air reservoir tanks from under the frame, and replace them with four NP Railway diesel diagram, NP 557–558 tanks that were installed on the roof of the locomotive, above the prime mover. These "torpedo tubes" as they were nicknamed, enabled the fuel and water tanks to be increased to each, although some railroads opted for roof-mounted air tanks and Schrenk & Frey (1988). p.159 fuel tanks on their freight ‘Geeps’.
Original buyers
Locomotives built by Electro-Motive Division, USA Owner Quantity Numbers NotesElectro-Motive Division (demonstrator)15251350 hp GP7m; to Atchison, Topeka and Santa Fe 99, renumbered 2899Pinkepank, Jerry A. (1973) p.56 This unit was built with a 567BC engine.3100 (ex-852), 200, 300to Chicago & North Western 1518–1520. 1518 first built, preserved and operating at Illinois Railway MuseumAberdeen and Rockfish Railroad1205Atchison, Topeka and Santa Fe2442650–28932855-2858 were built with 567C engines52788A–2792AGP7B; 2788A-2789A, 2791A-2792A were built with 567C enginesAtlanta and St. Andrews Bay2501–502Atlanta and West Point Rail Road5571–575Atlantic and East Carolina Railway1501Renumbered 406.Atlantic Coast Line Railroad154100-253Baltimore and Ohio Railroad33720–731, 740–746, 910–922, 6405728-729; 740-746 were built with 567BC engines; Long-hood-forwardBangor and Aroostook Railroad16560–575 Belt Railway of Chicago8470–477Boston and Maine Railroad231555–1577Butte, Anaconda and Pacific Railway3101–103Central of Georgia Railway15106–107, 120–132Central Railroad of New Jersey131520–1532Atlantic Coast Line Railroad (Charleston and Western Carolina Railway)21200–220To Atlantic Coast Line 254-274Chesapeake and Ohio Railway1805700–5719, 5739–5797, 5800–59005720–5738 built by GMDChicago and Eastern Illinois Railroad30203–232Chicago and North Western Railway1101521–1550, 1556–1559, 1562–1599, 1601–1603, 1625–1659Chicago and North Western (Chicago, St. Paul, Minneapolis and Omaha Railway—"Omaha Road")11151–161Chicago, Burlington and Quincy Railroad68200–267253-267 were built with 567BC engines Chicago Great Western Railway2120–121Chicago, Rock Island and Pacific Railroad113430–441, 1200–1237, 1250–1311, 1308 (2nd)1294-1299 were built with 567BC enginesClinchfield Railroad17900–916Colorado and Wyoming Railway2103–104Engines 103 & 104 are owned by the Pueblo Railway Foundation. Both locomotives are operable and used occasionally on Museum grounds.Colorado Fuel and Iron2101–102Engine 102 is owned by the Pueblo Railway Foundation. The locomotive is operable and used occasionally on Museum grounds.Atlantic Coast Line Railroad (Columbia, Newberry and Laurens Railroad)5100–104To Atlantic Coast Line 275-279Delaware, Lackawanna and Western Railroad20951–970To Erie Lackawanna, 1270-1284, 1405-1409.Denver and Rio Grande Western Railroad145100–5113Detroit and Toledo Shore Line Railroad1041–50Detroit, Toledo and Ironton Railroad24950–973964-973 were built with 567BC enginesErie Railroad521200–1246, 1400–1404To Erie Lackawanna, same numbersFlorida East Coast Railway15607–621Georgia and Florida Railroad6701–706Georgia Railroad161021–10361035-1036 were built with 567BC enginesGreat Northern Railway56600–655Long-hood-forwardIllinois Central Railroad488800–8801, 8850–8851, 8900–8911, 8950–89818800–8801, 8900–8911 had steam generatorsIllinois Terminal Railroad61600–1605Kansas City Southern Railway8155–162Kansas City Southern (Louisiana and Arkansas Railway)5150–154Kansas, Oklahoma and Gulf Railway9801–809Louisville and Nashville Railroad61400–440, 500–514, 501–502 (2nd), 550–552Maine Central Railroad19561–569, 571–580566-569 were built with 567BC enginesMeridian and Bigbee Railroad11Renumbered 101Midland Valley Railroad4151–154Minneapolis, St. Paul and Sault Ste. Marie Railroad ("Soo Line")7375–378, 381–383Missouri Pacific Railroad2084116–4194, 4197–43254116-4120, 4159-4165, 4203-4207, 4249-4253, 4284-4286, 4323-4324 owned by St. Louis, Brownsville and Mexico, 4121-4123, 4153-4158, 4197-4202, 4254-4255, 4287-4297, 4325 owned by International-Great Northern, 4290-4291, 4316-4320, 4325 were built with 567BC engines; 4292-4315, 4321-4324 were built with 567C engines.Missouri–Kansas–Texas Railroad331501–1529, 1761–17641700s had steam generators; Renumbered 91–123Nashville, Chattanooga and St. Louis Railway37700–731, 750–754700-705 built with EMD AAR TypeA trucksFerrocarriles Nacionales de México (National Railways of Mexico)26600–6601New York Central Railroad1695600–5611, 5626-5675, 5686-5712, 5738-5817Long-hood-forwardNew York Central Railroad (Peoria and Eastern Railway)145612-5625Long-hood-forwardNew York Central Railroad (Pittsburgh and Lake Erie Railroad)355676-5685, 5713-5737Long-hood-forwardNew York, Chicago and St. Louis Railroad ("Nickel Plate Road")48400–447Northern Pacific Railway20550–569to Burlington Northern Railroad 1624–1643;Schren & Frey (1988). p.162 560-569 were built with 567BC engines Pennsylvania Railroad668500–8512, 8545–8587, 8797–8806Long-hood-forwardPhelps Dodge Corporation71–2, 7–8, 27–29Portland Terminal Company Maine11081Reading Company44600–636, 660–666625-636 were built with 567BC engines; Long-hood-forwardRichmond, Fredericksburg and Potomac Railroad4101–104Seaboard Air Line Railroad1231700–1822Southern Railway572063–2077, 2156–2197Southern Railway (Cincinnati, New Orleans and Texas Pacific Railway)116200–6205, 6240–6244Southern Railway (Alabama Great Southern Railroad)56540–6544Southern Railway (Georgia Southern and Florida Railway)48210–8213St. Louis Southwestern Railway1320Renumbered 304St. Louis–San Francisco Railway129500–549, 555–632, 615 (2nd)Tennessee, Alabama and Georgia Railway3707–709Texas and Pacific Railway211110–1130Texas Mexican Railway3850–852Toledo, Peoria and Western Railway2102–103Union Pacific Railroad30700–729720-729 were built with 567BC enginesUnited States Army201821–1840Built with EMD AAR TypeA trucks; 12 later served on Alaska RR and 11 were retrucked with AAR Type B road trucks Wabash Railroad33450–452, 454–483453 built by GMDWestern Maryland Railway420–23Western Pacific Railroad13701–713Western Railway of Alabama6521–526Totals 2,617 5 GP7GP7B
Locomotives built by General Motors Diesel, Canada
GP7 locomotives were built at GMD's London Ontario plant for domestic Canadian railway purchasers, and for some US railroads like the C&O and Wabash who owned and operated over trackage in Canada (specifically the southern Ontario area).
Owner Quantity Numbers NotesAlgoma Central and Hudson Bay21150–170Canadian National Railways254824, 7555–75784824 rebuilt October 1958 with parts from wrecked F3A. 7555-7578 renumbered to 4800-4823 mid-1957. Long-hood-forwardCanadian Pacific Railway178409–84258410-8411 originally built with steam generatorsChesapeake and Ohio Railway195720–5738C&O 5720-5729 resold to NYC as 5818-5827 for their Canadian operationsQuebec North Shore and Labrador Railway22100–101, 104–123Toronto, Hamilton and Buffalo Railway771–77To CP (minus wrecked 71), all rebuilt as CP 1682-1687 Wabash Railroad1453Later to N&W 3453Total 112
Rebuilds, modifications and conversions
There are five GP7s on A J Kristopan's EMD Serial number page that reused previous serial numbers: B&O 6405 (preserved), CRI&P 1308 (2nd), L&N 501 (2nd) and 502 (2nd), and SLSF 615 (2nd). These rebuilt units were rebuilt as new on new frames. Another rebuild by GMD is that CN 4824 was rebuilt as a GP7 with parts from an F3A in October 1958.
Over 100 GP7s and four of the GP7Bs were built with 567BC or 567C engines starting in March 1953 through May 1954. These are noted on the roster above.
Many railroads rebuilt their GP7s with low short hoods; some railroads went further in their rebuilding than others. Missouri Pacific Railroad upgraded their GP7s with 567BC engines (a B-block upgraded to C-block specs) and replaced the standard EMD 2-stack exhaust with a 4-stack "liberated" exhaust, raising their power output to .Marre & Pinkepank (1988). p.192