View source for EMD F7

{{Short description|Model of 1500 hp North American cab diesel locomotive}}
{{More footnotes needed|date=April 2022}}
{{use mdy dates|date=December 2016}}
{{Infobox locomotive
| name=EMD F7
| powertype=Diesel-electric
| image=ATSF 309 (Flickr 22322834666).jpg
| caption=[[Atchison, Topeka, and Santa Fe Railway|Santa Fe Railway]] F7 #309 with the [[Grand Canyon Limited]] on August 19, 1967
| builder=[[Electro-Motive Diesel|General Motors Electro-Motive Division]] (EMD)<br />[[General Motors Diesel]] (GMD, Canada)
| buildmodel=F7
| builddate=February 1949 – December 1953
| totalproduction={{plainlist|
* 2,393 [[A unit]]s
* 1,463 [[B unit]]s
}}
| aarwheels=B-B
| uicclass=Bo’Bo’
| gauge={{track gauge|ussg|lk=on}}
| trucks = [[Blomberg B]]
| wheeldiameter = {{convert|40|in|mm|0|abbr=on}}
| minimumcurve = [[Degree of curvature|23°]] ({{convert|250.79|ft|m|abbr=on|disp=or}} [[radius]])
| wheelbase = {{convert|39|ft|m|2|abbr=on}}
| length=A unit: {{convert|50|ft|8|in|m|2|abbr=on}}<br />B unit: {{convert|50|ft|0|in|abbr=on}}
| width={{convert|10|ft|7|in|m|2|abbr=on}}
| height = {{convert|15|ft|m|2|abbr=on}}
| locoweight = {{convert|247300|lb|abbr=on}}
| fuelcap = 
| primemover = [[Electro-Motive Diesel|EMD]] [[EMD 567|16-567B]]
| rpmrange = 800
| enginetype = [[Two-stroke engine|Two-stroke]] [[V16 engine|V16]] [[Diesel engine|diesel]]
| aspiration = [[Roots-type supercharger|Roots blower]]
| displacement = {{convert|9072|cuin|L|abbr=on}}
| generator = EMD D-12
| tractionmotors = (4) EMD D-27-B
| headendpower = 
| cylindercount= 16
| cylindersize = {{convert|8+1/2|x|10|in|mm|0|abbr=on}}
| poweroutput={{convert|1500|hp|kW|abbr=on|lk=on}}
| maxspeed={{convert|65-102|mph|kph|0|abbr=on}}
| tractiveeffort = '''Starting:''' {{convert|56500|lbf|kN|abbr=on}} at 25% <br />
                   '''Continuous:''' {{convert|40000|lbf|kN|abbr=on}} at {{convert|9.3|mph|kph|0|abbr=on}}
| locale=[[North America]]
}}

The '''EMD F7''' is a model of {{convert|1500|hp|adj=on}} [[diesel-electric locomotive]] produced between February 1949 and December 1953 by the [[Electro-Motive Diesel|Electro-Motive Division of General Motors (EMD)]] and [[General Motors Diesel]] (GMD).<ref>{{Cite web |title=EMD F7 Data Sheet |url=https://www.thedieselshop.us/Data%20EMD%20F7.HTML |access-date=2025-10-03 |website=www.thedieselshop.us}}</ref>

Although originally promoted by EMD as a [[freight]]-hauling unit, the [[EMD F-unit|F-series]], including the F7 were also capable of passenger service, and used in hauling trains such as the [[Atchison, Topeka and Santa Fe Railway|Santa Fe Railway]]'s high-speed flagship trains, the ''[[Super Chief]], & [[El Capitan (passenger train)|El Capitan]]'', and the [[Ontario Northland]]'s ''[[Northlander]]''.

== History ==
The F7 was the fourth model in GM-EMD's successful line of [[EMD F-unit|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 [[EMD F3|F3]] model in GM-EMD's F-unit series, and was replaced in turn by the [[EMD F9|F9]]. Final assembly was at GM-EMD's [[La Grange, Illinois]], plant or GMD's [[London, Ontario]], facility. There was no F4, -5 or -6 model; "7" was chosen to match the contemporary twin-engine [[EMD E7|E7]], and was also applied to the new [[EMD GP7|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. {{convert|40000|lbf|kN|abbr=on}} for an F7 with {{convert|65|mph|km/h|abbr=on}} gearing, compared to {{convert|32500|lbf|kN|abbr=on}} 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 (locomotive)|prime mover]] is a 16-cylinder [[EMD 567|567B]] series [[diesel engine]] developing {{convert|1500|hp|MW|abbr=on}} at 800&nbsp;rpm. The 567B is a [[Roots-type supercharger|mechanically aspirated]] [[Two-stroke diesel engine|two-stroke]] design in a 45-degree [[V engine]] configuration, with {{convert|567|cuin|L|abbr=on}} displacement per cylinder, for a total of {{convert|9072|cuin|L|abbr=on}}.&nbsp; A direct current generator that is mechanically coupled to the [[flywheel]] end of the engine powers four [[traction motor]]s, with two motors mounted on each [[Blomberg B]] truck. EMD has built all of its major components since 1939.{{sfnp|Pinkepank|1973|pp=13, 26, 90–101}}{{sfnp|Ross|2003|pp=261, 273}}<ref>EMD 567C Engine Manual, EMD F7 Operators Manual</ref><ref name=Kettering>{{cite conference |url=https://books.google.com/books?id=QuUiAQAAMAAJ|title=History and Development of the 567 Series General Motors Locomotive Engine |author=Kettering, E.W. |date=November 29, 1951 |publisher=Electro-Motive Division, General Motors Corporation |conference=ASME 1951 Annual Meeting |location=Atlantic City, New Jersey}}</ref>

== 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 Light|Mars]] 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 ==
[[File:MARC 83 at Brunswick MD June 1994xRP - Flickr - drewj1946.jpg|thumb|[[MARC Train]] #83, a former B&O F7 rebuilt into an F9PH, at [[Brunswick (MARC station)|Brunswick, Maryland]] in 1994.]]
Several F7s were rebuilt by [[Morrison–Knudsen]] as '''F9PH'''s and used in passenger operations. Others were rebuilt as the "[[EMD FP10|FP10]]" and used by the [[Massachusetts Bay Transportation Authority]] for their [[MBTA Commuter Rail|commuter rail service]]. In addition, the Santa Fe had 190 of their F7As rebuilt into [[CF7]] 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 Train|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.<ref>{{Cite web |url=http://www.trainweb.org/csxrailfan/nov99/marc7100/marc7100.html |title=The MARC 7100 Returns! (November 1999 ''CSX Railfan Magazine'') |website=TrainWeb |access-date=September 1, 2012}}</ref>

==Licensees==
{{Expand section|date=July 2025}}
{{See also|Electro-Motive Diesel#Subcontractors and licensees}}
{{See also|Bulldog nose}}
Locomotives based on the F7 design were built by licensees in Europe and Australia.

== Original owners ==
A total of 2,393 cab-equipped lead [[A unit]]s and 1,463 cabless-booster or [[B unit]]s were built. Roughly fifty railroads purchased A units, B units, or both. The single largest buyer was the [[Southern Pacific Railroad]], which purchased 294 A units and 236 B units.{{sfn|Cook|2015|p=30}}{{sfn|Wilson|2017|pp=281–284}} Other significant buyers included the [[Atchison, Topeka and Santa Fe Railway]], the [[New York Central Railroad]], the [[Baltimore and Ohio Railroad]], and the [[Pennsylvania Railroad]].{{sfn|Cook|2015|p=30}} Locomotives intended for use in Canada were built by [[General Motors Diesel]], EMD's Canadian subsidiary. These included 76 for the [[Canadian National Railway]]{{sfn|Wilson|2017|p=172}} and 29 for the [[Canadian Pacific Railway]].{{sfn|Wilson|2017|p=175}} The [[Wabash Railroad]], although primarily an American railroad, purchased locomotives from both EMD and GMD.{{sfn|Wilson|2017|p=298}} The [[Ferrocarriles Nacionales de México]]'s (NdeM) 39 locomotives were built in the United States.{{sfn|Wilson|2017|p=248}}

== Surviving units ==
[[File:Conway Scenic Railroad Engine New Hampshire.JPG|thumb|Boston & Maine 4266 at the [[Conway Scenic Railroad]] in [[North Conway, New Hampshire|North Conway, N.H.]], seen on October 9, 2004.]]
Several F7s are preserved at shortlines, tourist lines, and museums, including:

* [[Aberdeen, Carolina and Western Railway]]<ref>{{Cite web |last=Franz |first=Justin |date=2021-05-17 |title=Aberdeen Carolina & Western F-units Debut in North Carolina |url=https://railfan.com/aberdeen-carolina-western-f-units-debut-in-north-carolina/ |access-date=2024-11-09 |website=Railfan & Railroad Magazine |language=en-CA}}</ref>
* [[Boone and Scenic Valley Railroad]]<ref>{{Cite web |title=F unit donated by Union Pacific arrives at Iowa heritage railroad |url=https://www.trains.com/trn/news-reviews/news-wire/f-unit-donated-by-union-pacific-arrives-at-iowa-heritage-railroad/ |access-date=2023-03-14 |website=Trains |date=March 14, 2023 |language=en-US}}</ref>
* [[California State Railroad Museum]]<ref>{{Cite web |title=Internal Combustion Locomotives |url=http://www.csrmf.org/events-exhibits/full-size-railroad-equipment/internal-combustion-locomotives |archive-url=https://web.archive.org/web/20150213025224/http://www.csrmf.org/events-exhibits/full-size-railroad-equipment/internal-combustion-locomotives |archive-date=February 13, 2015 |access-date=2024-11-09 |website=California State Railroad Museum}}</ref>
* [[Conway Scenic Railroad]]<ref>{{Cite web |last=Kfoury |first=Rick |date=2024-07-19 |title=50 Years of Conway Scenic Railroad |url=https://railfan.com/50-years-of-conway-scenic/ |access-date=2024-11-09 |website=Railfan & Railroad Magazine |language=en-CA}}</ref>
* [[Don Rhodes Mining and Transport Museum]]<ref>{{cite web|url=http://wpmuseum.railfan.net/locolist.html|title=The Western Pacific Surviving Locomotive List|last=Radecki|first=Alan |publisher=Railfan.net|access-date=August 25, 2013}}</ref><ref>[http://locopage.railpage.org.au/preserved.html (untitled)] {{webarchive |url=https://web.archive.org/web/20071013072033/http://locopage.railpage.org.au/preserved.html |date=October 13, 2007 }}</ref>{{unreliable source|date=November 2024}}
* [[Galveston Railroad Museum]]<ref>{{cite web|last1=Duncan|first1=Stephan|title=History Of The Warbonnets|url=http://www.galvestonrrmuseum.com/history-of-the-warbonnets.html|website=Galveston Railroad Museum|access-date=2016-01-25}}</ref>
* [[Illinois Railway Museum]]<ref>{{Cite web |title=Internal Combustion Locomotives |url=https://www.irm.org/collection/internal-combustion-locomotives/ |access-date=2024-11-09 |website=Illinois Railway Museum |language=en-US}}</ref>
* [[Manitoba Children's Museum]]<ref>{{cite web|title=Junction 9161|url=https://childrensmuseum.com/visit/permanent-galleries/junction-9161|publisher=Manitoba Children's Museum|accessdate=6 October 2012}}</ref>
* [[Museum of Alaska Transportation & Industry]]<ref>{{cite web |title={Untitled} |url=http://www.alaskarails.org/pix/former-loco/PD-1500.html |website=John's Alaska Railroad Web Page |access-date=3 January 2024}}</ref>{{unreliable source|date=November 2024}}
* [https://oregoncoastscenic.org/ Oregon Coast Scenic Railroad]<ref>{{Cite web |title=Oregon Coast Scenic Railroad {{!}} Train Rides on the Oregon Coast |url=https://oregoncoastscenic.org/ |access-date=2024-12-04 |website=Oregon Coast Scenic Railroad |language=en-US}}</ref>
* [[Reading Blue Mountain and Northern Railroad]]<ref>{{Cite web |last=Wrinn |first=Jim |date=December 13, 2019 |title=Last two NS F-units sold to North Carolina short line |url=https://trn.trains.com/news/news-wire/2019/12/13-last-two-ns-f-units-sold-to-north-carolina-short-line |archive-url=https://web.archive.org/web/20191214054148/https://trn.trains.com/news/news-wire/2019/12/13-last-two-ns-f-units-sold-to-north-carolina-short-line |archive-date=December 14, 2019 |website=Trains Magazine}}</ref>
* [[Toronto Railway Museum]] cab of ex-[[Canadian National Railway]] F7A 9159 - built 1951 and scrapped 1991; cab acquired by TRM in 2006.

== See also ==
{{portal|Trains}}
*[[EMD FP7]]
*[[NOHAB]]
*[[List of GM-EMD locomotives]]
*[[List of GMD Locomotives]]

== Notes ==
{{reflist}}

== References ==
* {{cite magazine | last=Cook | first=Preston |title=F Units, T to 9 | magazine=Classic Trains | date=Spring 2015 | pages=20–35 | issn=1527-0718 }}
* {{Pinkepank diesel spotters guide 2}}
* {{cite book|editor-first=David|editor-last=Ross|title=The Encyclopedia of Trains and Locomotives|year=2003|isbn=978-0-7607-9679-5|publisher=Barnes & Noble |location=New York}}
* {{Wilson-Guide}}

== Further reading ==
* {{Dorin-North Western|pages=119–121}}
* Hawkins, R. W. (2020, November 27). Southern Railway CabUnits. HawkinsRails. Retrieved November 22, 2021, from https://hawkinsrails.net/mainlines/sou/sou_mp_cabs.htm.
* {{Lamb-Evolution}}
* {{Marre-diesel-50}}
* {{Schafer-Vintage Diesel}}
* {{Solomon-American Diesel}}
* {{Solomon-EMD F-Unit}}
* {{Solomon-EMD Locomotives}}
* {{Solomon-Vintage Diesel}}
* {{Solomon-Electro-Motive}}
* {{Solomon-North American Locomotives}}
* Rio Grande Modelling and Historical Society. DRGW EMD F7 Roster. D&amp;RGW F7 diesel roster. Retrieved November 22, 2021, from https://www.rgmhs.org/data/diesels/f7.html {{Webarchive|url=https://web.archive.org/web/20211123015619/https://www.rgmhs.org/data/diesels/f7.html |date=November 23, 2021 }}.
* The Diesel Shop. EMD F7A and F7B. EMD F7 Data Sheet. Retrieved November 22, 2021, from https://www.thedieselshop.us/Data%20EMD%20F7.HTML.
* {{Wilson-F Units}}
* General Motors Electro-Motive Division Service Department "Locomotive Reference Data" published January 1, 1959, 286 pages.
* General Motors of Canada Limited Diesel Division "Serial Number Record" 1942–1990, includes import of EMD units to Canada, 230 pages.

== External links ==
{{Commons category|EMD F7 locomotives}}
* [https://www.american-rails.com/e1074.html Roster]

{{Amtrak rolling stock}}
{{EMD cab and cowl}}

[[Category:B-B locomotives]]
[[Category:Electro-Motive Division locomotives|F07]]
[[Category:General Motors Diesel locomotives|F07]]
[[Category:Diesel–electric locomotives of the United States]]
[[Category:Railway locomotives introduced in 1949]]
[[Category:Locomotives with cabless variants]]
[[Category:Standard-gauge locomotives of the United States]]
[[Category:Passenger locomotives]]
[[Category:Standard-gauge locomotives of Canada]]
[[Category:Standard-gauge locomotives of Mexico]]
[[Category:Diesel–electric locomotives of Canada]]
[[Category:Diesel–electric locomotives of Mexico]]
[[Category:Streamlined diesel locomotives]]
[[Category:Atchison, Topeka and Santa Fe Railway locomotives]]
[[Category:Baltimore and Ohio locomotives]]
[[Category:Canadian National Railway locomotives]]
[[Category:Canadian Pacific Railway locomotives]]
[[Category:New York Central Railroad locomotives]]
[[Category:Pennsylvania Railroad locomotives]]
[[Category:Southern Pacific Railroad locomotives]]