The EMD GP7 is a four-axle ( B-B) diesel-electric

locomotive A locomotive is a rail transport, rail vehicle that provides the motive power for a train. Traditionally, locomotives pulled trains from the front. However, Push–pull train, push–pull operation has become common, and in the pursuit for ...

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 A hood unit, in North American railroad terminology, is a body style for diesel and electric locomotives where the body is less than full-width for most of its length and walkways are on the outside. In contrast, a cab unit has a full-width ca ...

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 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 The Atchison, Topeka and Santa Fe Railway , often referred to as the Santa Fe or AT&SF, was one of the largest Class 1 railroads in the United States between 1859 and 1996. The Santa Fe was a pioneer in intermodal freight transport; at vario ...

), 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 The American Locomotive Company (often shortened to ALCO, ALCo or Alco) was an American manufacturer that operated from 1901 to 1969, initially specializing in the production of locomotives but later diversifying and fabricating at various time ...

Fairbanks-Morse Fairbanks, Morse and Company was an American manufacturing company in the late 19th and early 20th century. Founded in 1823 as a manufacturer of weighing scale, weighing scales, it later diversified into pumps, engines, windmills, coffee grinder ...

, and Baldwin had all introduced

road switcher A road switcher locomotive is a type of railroad locomotive designed to both haul railroad car, railcars in mainline service and Shunting (rail), shunt them in railroad yards. Both type and term are North American in origin, although similar t ...

s 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 Cleveland is a city in the U.S. state of Ohio and the county seat of Cuyahoga County, Ohio, Cuyahoga County. Located along the southern shore of Lake Erie, it is situated across the Canada–United States border, Canada–U.S. maritime border ...

. 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 railroad Railroad classes are the system by which Rail freight transport, freight railroads are designated in the United States. Railroads are assigned to Class I, II or III according to annual revenue criteria originally set by the Surface Transportatio ...

s, 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 Engineers, as practitioners of engineering, are professionals who Invention, invent, design, build, maintain and test machines, complex systems, structures, gadgets and materials. They aim to fulfill functional objectives and requirements while ...

’s

control stand A control stand is a diesel-electric locomotive subsystem which integrates engine functional controls and brake functional controls, whereby all functional controls are "at hand" (within reach of the locomotive engineer from their customary seati ...

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

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).

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 The Missouri Pacific Railroad , commonly abbreviated as MoPac, was one of the first railroads in the United States west of the Mississippi River. MoPac was a Class I railroad growing from dozens of predecessors and mergers. In 1967, the railroad o ...

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

Illinois Central Railroad The Illinois Central Railroad , sometimes called the Main Line of Mid-America, is a railroad in the Central United States. Its primary routes connected Chicago, Illinois, with New Orleans, New Orleans, Louisiana, and Mobile, Alabama, and thus, ...

rebuilt most of its GP7s with 567BC engines, 4-stack exhausts, paper air-intake filters, 26-L brakes (their original 6-BL brakes made them operationally incompatible with locomotives fitted with 24-RL brakes).Marre & Pinkepank (1988). p.183 All but the first locomotive rebuilt had their front (short) hood reduced in height for improved crew visibility. The IC designated these rebuilt locomotives GP8. The IC acquired many second-hand units through Precision National Corporation (PNC), and then started offering their GP8/GP10 rebuilding services to other railroads through their Paducah Shops (note, a rebuilt "Paducah Geep" was designated a GP8 or GP10 depending on the power output of the rebuilt engine, not necessarily what it was rebuilt from). In 1960 the Alaska Railroad purchased a dozen GP7Ls from the US Army and rebuilt eleven of them in 1965 with low short hoods for better visual clearance. One of the ten remaining Alaska GP7s was rebuilt by Morrison-Knudsen in 1976. The other nine units were rebuilt at Paducah Shops in 1976-1977.

Canadian Pacific Railway The Canadian Pacific Railway () , also known simply as CPR or Canadian Pacific and formerly as CP Rail (1968–1996), is a Canadian Class I railway incorporated in 1881. The railway is owned by Canadian Pacific Kansas City, Canadian Pacific Ka ...

rebuilt their GP7 fleet in the early 1980's as GP7u units for yard service, including a chopped short hood, new numberboards and front cab windows, and upgrading the 567B prime movers with 645 power assemblies and to "BC" engine block specs (some upgraded with 567C engine blocks out of retired F-units).

Preservation

Numerous GP7s have been preserved on tourist lines and in museums. Holders include: * Conway Scenic Railroad *

Florida Railroad Museum The Florida Railroad Museum is a railroad museum located in Parrish, Florida. The museum operates a heritage railroad and offers round-trip tourist excursions along six miles of the former Seaboard Air Line Railway, Seaboard Air Line Sarasota Su ...

* Illinois Railway Museum * Lebanon Mason Monroe Railroad * Minnesota Transportation Museum * Tennessee Valley Railroad Museum * United Railroad Historical Society of New Jersey * Western Pacific Railroad Museum * Grand Canyon Railway * Toronto Railway Museum * Southeastern Railway Museum * Stone Mountain Scenic Railroad * Hocking Valley Scenic Railway * Grapevine Vintage Railroad * Conrad Yelvington Distributors Railroad

References