EMD F7B, D&RGW 5603, 5-Stripe Scheme, Paragon3 Sound/DC/DCC

The EMD F7 was a 1,500 horsepower (1,100 kW) Diesel-electric locomotive produced between February 1949 and December 1953 by the Electro-Motive Division of General Motors (EMD) and General Motors Diesel (GMD).

Although originally promoted by EMD as a freight-hauling unit, the F7 was also used in passenger service hauling such trains as the Santa Fe Railways Super Chief and El Capitan.

The F7 was the fourth model in GM-EMDs successful line of F unit locomotives, and by far the best-selling cab unit of all time. In fact, more F7s were built than all other F units combined. It succeeded the F3 model in GM-EMDs F unit sequence, and was replaced in turn by the F9. Final assembly was at GM-EMDs La Grange, Illinois plant or GMDs London, Ontario facility.

The F7 differed from the F3 primarily in internal equipment (mostly electrical) and some external features. Its continuous tractive effort rating was 20% higher (e.g. 40,000 lb (18,000 kg) for an F7 with 65 mph (105 km/h) gearing, compared to 32,500 lb (14,700 kg) for an F3 with the same gearing.) A total of 2,366 cab-equipped lead A units and 1,483 cabless-booster or B units were built. Many F7s remained in service for decades, as railroads found them economical to operate and maintain.