EMD F7 at a glance
| Builder | General Motors Electro-Motive Division / General Motors Diesel |
|---|---|
| Power | 1,500 hp per unit |
| Prime mover | EMD 16-567B V16 two-stroke diesel |
| Wheel arrangement | B-B — four powered axles |
| Production | 1949–1953 |
| Length | F7A about 50 ft 8 in; F7B about 50 ft |
| Common freight gearing speed | About 65 mph; other gearings existed |
| Body styles | Cab-equipped A unit and cabless booster B unit |
An icon of the diesel transition
The F7 arrived while North American railroads were rapidly replacing steam power. Its streamlined carbody made it visually distinctive, while multiple-unit controls allowed railroads to combine several A and B units into a locomotive set for heavy trains.
A units and B units
An F7A has a cab and controls. An F7B is a cabless booster designed to work in a multiple-unit consist. Railroads could arrange A and B units in combinations that matched the power needed for a train.
How to identify it
The rounded 'bulldog' nose, windshield arrangement and full-width streamlined carbody are the first clues. F-unit phases and railroad modifications can make precise identification challenging, so number histories and body details matter.
Freight and passenger service
EMD marketed the F7 primarily for freight, but railroads also used F7s in passenger service. Some passenger-equipped units had steam generators to provide heat for passenger cars in the pre-head-end-power era.
Identification reminder
Locomotives are rebuilt, repainted and modified during long careers. Use several clues together—road number, trucks, hood and radiator details, cab shape and known roster history—rather than relying on paint alone.
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Ask Ask the Conductor about this locomotive, how it works, where it ran or how it compares with another model.
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