The EMD GP7 Series, An American Locomotive Icon

EMD originally began as the Electro-Motive Corporation and has its beginnings in 1922 being based out of Cleveland, Ohio building inexpensive motorcars. With the purchase of the company in 1930 by General Motor, and more resources at its disposal the company began developing the precursor of the modern-day diesel-electric road unit (cabs and road-switchers), the streamlined trainset, which consisted of a powered car permanently attached to a few coaches (usually two or three cars). The most famous of these streamlined trainsets was the Burlington Zephyrs, a beautiful streamlined stainless steel creation (originally powered by Winton engines, which would also become a subsidiary of GM) that was extremely lightweight and fast. The original trainset, the Zephyr 9900, made headlines in 1934 when it completed a non-stop journey from Denver to Chicago in a little over 13 hours.

Because the power cars with these trainsets were permanently attached to the coaches EMC sought to design a locomotive free of this articulated setup but designed in such a manner that a railroad could still attach it to any passenger train and obtain the same, smooth streamlined look. This it did with the unveiling of the EA model in 1937, the first in a long line of passenger diesel locomotive designs that would come to be known as the E series.

Not surprisingly, soon after the EA unveiling the company decided to take things a step further and develop the first true diesel road unit, capable of pulling long freights in main line service. In 1939 it introduced the FT model (perhaps the key difference between the E and F series was that Fs rode on B-B trucks whereas Es rode on C-Cs and carried a noticeably longer carbody), the first in EMC’s F series and one of the most success diesel-electric designs of all time. The F series would go on to define American railroading for years and you can still see it in regular use today, over 60 years after it first debuted! The FT (which stood for Freight, Twenty-seven hundred horsepower) was a superb locomotive and although its 2,700 horsepower came from an A-B setup of a cab (A) and booster (B) units rated at 1,350 horsepower each, it was quickly loved by railroads for the efficiencies it held over steam such as its ruggedness and ease of maintenance.

Following the success of its cab units, EMD realized that there was a market to be made in the road-switchers, which at the time was mostly dominated by Alco with its RS series. Its first attempt at this type of locomotive, which gave the train crews both excellent vision all around the locomotive for switching and local service as well as enough horsepower to be used in main line operations, was the BL2. Although unsuccessful from a sales standpoint the BL2 was really a mere stepping-stone for its next model, the GP series (meaning General Purpose).

The first in the series was the four-axle, GP7, which began production in 1949. Still commonly found today on several Regionals and shortlines 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. 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).

Through 1954 the model sold an astounding 2,600+ 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).

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 (although the Es, Fs and other streamlined locomotives usually handled the prominent passenger trains).

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.

For more information on the GP7 series consider Mike Schafer’s Vintage Diesel Locomotives, which looks at virtually all of the classic builders and models from Alco PAs to early EMD Geeps. If you’re interested in classic EMDs, or diesels in general, this book gives an excellent general history of both.

Also, Brian Solomon’s The American Diesel Locomotive also studies many of the same diesel models and builders as Mr. Schafer’s publication although at nearly twice the size the book goes into a bit more detail than Vintage Diesel Locomotives and also covers newer models. All in all, though, both books are a great read and you shouldn’t be disappointed with them, not to mention that they are loaded with photos (many in color)! If you're interested in perhaps purchasing these books please visit The Railroad Diamond by clicking the tab in the menu to your left marked "TRD Store".