The EMD F7 is a model of 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 In transportation, cargo refers to goods transported by land, water or air, while freight refers to its conveyance. In economics, freight refers to goods transported at a freight rate for commercial gain. The term cargo is also used in ...

-hauling unit, the F7 was also capable of passenger service, and used in hauling trains such as the Santa Fe Railway's high-speed flagship trains, the '' Super Chief, & El Capitan'', and the Ontario Northland's '' Northlander''.

History

The F7 was the fourth model in GM-EMD's 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. The F7 succeeded the F3 model in GM-EMD's F-unit series, and was replaced in turn by the F9. Final assembly was at GM-EMD's La Grange, Illinois, plant or GMD's

London, Ontario London is a city in southwestern Ontario, Canada, along the Quebec City–Windsor Corridor. The city had a population of 422,324 according to the 2021 Canadian census. London is at the confluence of the Thames River (Ontario), Thames River and N ...

, facility. There was no F4, -5 or -6 model; "7" was chosen to match the contemporary twin-engine E7, and was also applied to the new GP7 road-switcher. The F7 differed from the F3 primarily in internal equipment—mostly electrical—and some external features. Its continuous tractive effort rating was 20 percent higher, e.g. for an F7 with gearing, compared to for an F3 with the same gearing. Many F7s remained in service for decades, as railroads found them economical to operate and maintain. However, the locomotive was not very popular with yard crews who operated them in switching service because they were difficult to mount and dismount, and it was also nearly impossible for the engineer to see hand signals from a ground crew without leaning way outside the window. As most of these engines were bought and operated before two-way radio became standard on most American railroads, this was a major point of contention. In later years, with the advent of the "road switchers" such as the EMD GP7, F-units were primarily used in "through freight" and " unit train" service where there was little or no switching to be done.

Engine and powertrain

The F7's prime mover is a 16-cylinder 567B series

diesel engine The diesel engine, named after the German engineer Rudolf Diesel, is an internal combustion engine in which Combustion, ignition of diesel fuel is caused by the elevated temperature of the air in the cylinder due to Mechanics, mechanical Compr ...

developing at 800 rpm. The 567B is a mechanically aspirated two-stroke design in a 45-degree V engine configuration, with displacement per cylinder, for a total of . A direct current generator that is mechanically coupled to the flywheel end of the engine powers four traction motors, with two motors mounted on each Blomberg B truck. EMD has built all of its major components since 1939.

Identification

There are no easily identifiable differences between late F3 production and early F7 production; the major differences were all internal electrical system changes. However, no F7 had the "chicken wire" grilles seen on most F3s, and no F3s had later F7 changes described below under ''Phases''. The F9 is distinguishable from the late F7 by having five, rather than four, carbody center louver groups covering the carbody filters. The additional one is placed ahead of the first porthole, where F7s have no openings. The F9's greater power output, of course, cannot be seen from the outside. There were also two main classes of F7s: passenger and freight. Most passenger units had upper and lower headlights, but there were exceptions. Many freight units had the upper

Mars Mars is the fourth planet from the Sun. It is also known as the "Red Planet", because of its orange-red appearance. Mars is a desert-like rocky planet with a tenuous carbon dioxide () atmosphere. At the average surface level the atmosph ...

or Pyle brand warning light as well. And some passenger units only had a single upper headlight, i.e. the Pennsylvania. Many units eventually had the upper lights or the door light removed/plated over and the Mars/Pyle light removed. These early warning lights had a motor and linkages that often required maintenance in the shops.

Rebuilds

MARC 83 at Brunswick MD June 1994xRP - Flickr - drewj1946

Several F7s were rebuilt by Morrison–Knudsen as F9PHs and used in passenger operations. Others were rebuilt as the " FP10" and used by the

Massachusetts Bay Transportation Authority The Massachusetts Bay Transportation Authority (abbreviated MBTA and known colloquially as "the T") is the public agency responsible for operating most public transportation services in Greater Boston, Massachusetts. The MBTA transit network in ...

for their commuter rail service. In addition, the Santa Fe had 190 of their F7As rebuilt into

CF7 The Santa Fe CF7 is an EMD F-unit railroad locomotive that has had its in order to adapt the unit for switcher, switching duty. All of the conversions were performed by the Atchison, Topeka & Santa Fe Railway's Cleburne, Texas, workshops between ...

hood units in the 1970s. Only one original F7 unit from the railway exists to this day, preserved in running condition at the California State Railroad Museum in Sacramento. In the early 2000s, a single unpowered EMD F cab unit #7100 (ex-Baltimore & Ohio Railroad F7 #4553) operated on MARC, occasionally substituting for a cab car. In addition to serving as an all-purpose control unit, it also had a head-end power generator that supplied electricity to the train.

Original owners

A total of 2,393 cab-equipped lead A units and 1,463 cabless-booster or B units were built. Roughly fifty railroads purchased A units, B units, or both. The single largest buyer was the

Southern Pacific Railroad The Southern Pacific (or Espee from the railroad initials) was an American Railroad classes#Class I, Class I Rail transport, railroad network that existed from 1865 to 1996 and operated largely in the Western United States. The system was oper ...

, which purchased 294 A units and 236 B units. Other significant buyers included 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 ...

, the

New York Central Railroad The New York Central Railroad was a railroad primarily operating in the Great Lakes region, Great Lakes and Mid-Atlantic (United States), Mid-Atlantic regions of the United States. The railroad primarily connected New York metropolitan area, gr ...

, the

Baltimore and Ohio Railroad The Baltimore and Ohio Railroad was the oldest railroads in North America, oldest railroad in the United States and the first steam engine, steam-operated common carrier. Construction of the line began in 1828, and it operated as B&O from 1830 ...

, and the Pennsylvania Railroad. Locomotives intended for use in Canada were built by General Motors Diesel, EMD's Canadian subsidiary. These included 76 for the Canadian National Railway and 29 for the

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 ...

. The

Wabash Railroad The Wabash Railroad was a Class I railroad that operated in the mid-central United States. It served a large area, including track in the states of Ohio, Indiana, Illinois, Iowa, Michigan, and Missouri and the province of Ontario. Its primary con ...

, although primarily an American railroad, purchased locomotives from both EMD and GMD. The Ferrocarriles Nacionales de México's (NdeM) 39 locomotives were built in the United States.

Surviving units

Conway Scenic Railroad Engine New Hampshire

Several F7s are preserved at shortlines, tourist lines, and museums, including: * Aberdeen, Carolina and Western Railway * Boone and Scenic Valley Railroad * California State Railroad Museum * Conway Scenic Railroad * Don Rhodes Mining and Transport Museum * Galveston Railroad Museum * Illinois Railway Museum * Manitoba Children's Museum * Museum of Alaska Transportation & Industry
Oregon Coast Scenic Railroad
* Reading Blue Mountain and Northern Railroad

Notes

References

* * * *

External links

Roster
{{EMD cab and cowl B-B locomotives F07 F07 Diesel–electric locomotives of the United States Railway locomotives introduced in 1949 Locomotives with cabless variants Standard-gauge locomotives of the United States Passenger locomotives Standard-gauge locomotives of Canada Standard-gauge locomotives of Mexico Diesel–electric locomotives of Canada Diesel–electric locomotives of Mexico Streamlined diesel locomotives Atchison, Topeka and Santa Fe Railway locomotives Baltimore and Ohio locomotives Canadian National Railway locomotives Canadian Pacific Railway locomotives New York Central Railroad locomotives Pennsylvania Railroad locomotives Southern Pacific Railroad locomotives