The EMD F7 is 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).
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, facility.
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. 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.
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 developing 1,500 hp (1.1 MW) at 800 rpm. The 567B is a mechanically aspirated two-stroke design in a 45 degree V engine configuration, with 567 cu in (9.29 L) displacement per cylinder, for a total of 9,072 cu in (148.66 L). 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. Starting in August 1953 EMD installed 567BC and 567C engines in a few F7s, see roster below.
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 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.
The identification of locomotive "phases" is a creation of railfans, although now used in Diesel Spotters Guide. EMD used no such identification, and instead kept track of the marketing name (F7) and individual locomotives' build numbers. During the production cycle of a model, EMD would often make detail changes that were not readily apparent to the casual observer. To keep better track of the variations of locomotives identified the same by the manufacturer, railfans began referring to phases (critical changes to a locomotive line).
Despite not being official designations, the phase description is useful. However, many of the changes described are cosmetic, easily changed features of a locomotive: e.g., roof fans, body panels, grilles and the like could be and sometimes were updated or swapped. Most of the phase differences on the F7 were concerned only with A units; B units varied far less. The following are normally identified as F7 phases:
Phase I (early)
Built from February 1949. Upper grille with horizontal openings. Four horizontal louvered openings on center body panel. 36-inch (914 mm) dynamic brake fan, if dynamic brakes fitted. Flush windshield gasket changed to raised in July 1949. Square cab door corners with kick plates on the steps beneath. Wing window short with square corners. Single drip strip over cab windows and door. Square end door window. Round sand filler cover. Rear overhang.
Phase I (late)
Built from March 1950. Upper grille started out horizontal, as in early Phase I; from March 1951, some locomotives were built with vertical-slotted "Farr-Air" grilles, and by October 1951, all had them. Cab doors became round-cornered, and the kick plates were deleted. The wing windows became taller, with round corners. Two drip strips; one over cab windows, second over door. The end door window became round after November 1950.
Built from February 1952. All upper grilles vertical "Farr-Air" type. Center car body louvres became vertical-slotted. Sand filler now with a horizontal, rectangular pull handle. From June 1952, 48-inch (1,219 mm) dynamic brake fans began to be introduced; from October 1952, all dynamic-brake equipped locomotives had them. At that latter date, locomotives no longer had a rear overhang.
Locomotives built by Electro-Motive Division, USA
|Electro-Motive Division (demonstrators)||801–802 to Great Northern 272A,B,
1950A,B to Louisville & Nashville 857–858
5040 to Union Pacific 1483
459A,D to Union Pacific 1481–1482
|Electro-Motive Division (test unit)||930 to B&M 4268A|
|Electro-Motive Division (demonstrators)||to Union Pacific 1496B,C (B units)
7002–7003 FP7-F7B-F7B demonstrators; to Soo Line (Wisconsin Central) 2500B–2501B
9052–9053 FP7-F7B-F7B demonstrators; to Soo Line 500B–501B
|Atlantic Coast Line Railroad||FT 317 wrecked, November 1950; rebuilt as F7 317:2, May 1951. Wrecked again in a head-on collision with F7 417, October 1956; both rebuilt as F9 317:3 and 417:2, May 1957.
|Atlantic Coast Line Railroad (C&WC)|
|Alaska Railroad||1506-1508 were built with 567BC engines|
|Atchison, Topeka and Santa Fe Railway||37–47 passenger, 202-280 freight, 300-344 dual service (passenger and freight), 48A rebuilt by EMD from Santa Fe F3B 32A (1st), used by EMD as a demo for several years. 269LABC-280LABC were built with 567BC engines.|
|Bessemer and Lake Erie Railroad|
|Boston and Maine Railroad|
|Baltimore and Ohio Railroad|
|Chicago, Burlington and Quincy Railroad|
|Chicago Great Western Railway|
|Chicago and North Western Railway|
|Chicago, St. Paul, Minneapolis and Omaha Railway ("Omaha Road")||6501A was rebuilt to EMD F9A test unit 462|
|Chicago, Rock Island and Pacific Railroad||675–677 passenger|
|Chesapeake and Ohio Railway||8500s passenger (with FP7)|
|Colorado and Southern Railway|
|Delaware, Lackawanna and Western Railroad|
|Denver and Rio Grande Western Railroad|
|Erie Railroad||713 ABBA set was originally numbered 807A-D|
|Fort Worth and Denver City Railway|
|Gulf, Mobile and Ohio Railroad|
|Great Northern Railway||350–365, 500s passenger|
|Kansas, Oklahoma and Gulf Railway|
|Kansas City Southern Railway|
|Kansas City Southern (Louisiana and Arkansas Railway)|
|Louisville and Nashville Railroad|
|Lehigh Valley Railroad|
|Milwaukee Road||90B–105B passenger (with FP7)|
|Missouri Pacific Railroad|
|Missouri Pacific Railroad (International-Great Northern Railroad)|
|Missouri Pacific Railroad (St. Louis, Brownsville and Mexico Railway)|
|Minneapolis and St. Louis Railway|
|Nashville, Chattanooga and St. Louis Railway|
|Northern Pacific Railway||6000s freight (as dual service locomotives), 6500s passenger|
|New York Central Railroad|
|Richmond, Fredericksburg and Potomac Railroad|
|St. Louis–San Francisco Railway|
|Soo Line||500s passenger (with FP7)|
|Soo Line (Wisconsin Central Railway||2228AB-2230AB were built with 567C engines.|
|Southern Railway (CNO&TP)|
|Southern Railway (AGS)|
|Southern Pacific Railroad|
|Southern Pacific Railroad (T&NO)|
|Southern Pacific Railroad (SSW)||SSW 920D (923) was an FT rebuilt on an F7 underframe, SSW 921 2nd was an FT rebuilt on an F7 underframe|
|Spokane, Portland and Seattle Railway||to BN 9754,9756,9758,9760|
|Texas Mexican Railway|
|Texas and Pacific Railway|
|Union Pacific Railroad||910B,C with FP7|
|Western Maryland Railway||WM 61B, 65B, 239B, 241B, and 243B were built with 567C engines.|
|Western Pacific Railroad||800s passenger (with FP7)|
Locomotives built by General Motors Diesel, Canada
|Canadian National Railways|
|Canadian Pacific Railway||Ordered with FP7|
|Wabash Railroad||Ordered for service in Canada|
Export locomotives built by Electro-Motive Division, USA for Mexico
|Ferrocarriles Nacionales de México|
|Mexican Ministry of Communications and Public Works ("SCOP")|
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 for their 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.
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.
Several F7s survive today, mostly in museums and tourist railroads.
- The Norfolk Southern Railway previously rostered four F7 units (two A units and two B units), all which were rebuilt in 2007. The two A units were rebuilt into F9PH units, and rebuilt again into F9A units. They were used on inspection trains and Office Car Specials until 2019, when NS sold the four units. Two of them were sent to the Aberdeen, Carolina and Western Railway, while the other two were sent to the Reading Blue Mountain and Northern Railroad.
- The Escanaba and Lake Superior Railroad (as of October 2011) operates an FP7A (#600) in main line freight service. The unit is the former Milwaukee Road #96A, and was purchased in 2005 from the Wisconsin and Southern Railroad.
- The California State Railroad Museum in Sacramento, California, has three F7s.
- Western Pacific F7A 913: This engine is currently listed as serviceable.
- Atchison, Topeka & Santa Fe No. 347C GM-EMD 1949 F7A was given as a gift to the museum by Santa Fe in March 1986 and is repainted to original warbonnet colors. Listed as operable.
- Southern Pacific No. 6402 GM-EMD 1952 F7A was also given as a gift by the Pacific Coast Chapter of the Railroad and Historical Society in June 1978. Listed as operable.
- The Don Rhodes Mining and Transport Museum at Port Hedland, Western Australia, has a former Western Pacific Railroad F7A: 923A. It was sold to Mt. Newman Mining and operated as locomotive #5451 before being transferred to the Shire of Port Hedland. It is now a static display, with the prime mover removed.
- The Galveston Railroad Museum owned F7As Texas Limited #100 (ex-Southern Pacific #6379) and #200 (ex-Southern Pacific #6309). This duo headed the "Texas Limited" passenger train which made runs to and from Houston until track speed restrictions and liability insurance costs ended operations.[when?] Both units were scrapped in 2011 after extensive damage resulting from being submerged in saltwater after Hurricane Ike. The museum now owns 2 more F7's, #315 and #316, which are both painted in ATSF warbonnet colors. Both units are ex-Southern Pacific, #'s 6443 (315) and 365 (316); they have parts salvaged from the Texas Limited units.
- Cook 2015, p. 30
- Pinkpank, Jerry A (1973). The Second Diesel Spotter's Guide. Kalmbach Books. pp. 13, 26, 90–101. ISBN 0-89024-026-4.
- Ross, David, ed. (2003). The Encyclopedia of Trains and Locomotives. pp. 261, 273. ISBN 978-0-7607-9679-5.
- EMD 567C Engine Manual, EMD F7 Operators Manual
- Kettering, E.W. (November 29, 1951). History and Development of the 567 Series General Motors Locomotive Engine. ASME 1951 Annual Meeting. Atlantic City, New Jersey: Electro-Motive Division, General Motors Corporation.
- "The MARC 7100 Returns! (November 1999 CSX Railfan Magazine)". TrainWeb. Retrieved September 1, 2012.
- "AltoonaWorks.info -- NS F Unit Rebuilds".
- "NS to dispose of executive F units, other roster oddities | Trains Magazine".
- "Last two NS F-units sold to North Carolina short line | Trains Magazine".
- Glischinski, Steve (2007). Regional Railroads of the Midwest. St. Paul, Minnesota: MBI Publishing Company. ISBN 978-0-7603-2351-9.
- "Internal Combustion Locomotives" Archived February 13, 2015, at the Wayback Machine. California State Railroad Museum Foundation. Retrieved 28 February 2015.
- Radecki, Alan. "The Western Pacific Surviving Locomotive List". Railfan.net. Retrieved August 25, 2013.
- (untitled) Archived October 13, 2007, at the Wayback Machine
- Duncan, Stephan. "History Of The Warbonnets". Galveston Railroad Museum. Retrieved January 25, 2016.
- Burns, A. (n.d.). EMD F7 locomotives. American-Rails. Retrieved November 22, 2021, from https://www.american-rails.com/e1074.html.
- Cook, Preston (Spring 2015). "F Units, T to 9". Classic Trains. pp. 20–35. ISSN 1527-0718.
- Dorin, Patrick C. (1972). Chicago and North Western Power. Burbank, California: Superior Publishing. pp. 119–121. ISBN 0-87564-715-4.
- Hawkins, R. W. (2020, November 27). Southern Railway CabUnits. HawkinsRails. Retrieved November 22, 2021, from http://hawkinsrails.net/mainlines/sou/sou_mp_cabs.htm.
- Lamb, J. Parker (2007). Evolution of the American Diesel Locomotive. Railroads Past and Present. Bloomington, Indiana: Indiana University Press. ISBN 978-0-253-34863-0.
- Marre, Louis A. (1995). Diesel Locomotives: The First 50 Years: A Guide to Diesels Built Before 1972. Railroad Reference Series. Waukesha, Wisconsin: Kalmbach Publishing. ISBN 978-0-89024-258-2.
- Pinkepank, Jerry A. (1973). The Second Diesel Spotter's Guide. Milwaukee, Wisconsin: Kalmbach Publishing. pp. 12, 91–94. ISBN 978-0-89024-026-7.
- Schafer, Mike (1998). Vintage Diesel Locomotives. Enthusiast Color Series. Osceola, Wisconsin: MBI Publishing. ISBN 978-0-7603-0507-2.
- Solomon, Brian (2000). The American Diesel Locomotive. Osceola, Wisconsin: MBI Publishing Company. ISBN 978-0-7603-0666-6.
- Solomon, Brian (2005). EMD F-Unit Locomotives. North Branch, Minnesota: Specialty Press. ISBN 978-1-58007-192-5.
- Solomon, Brian (2006). EMD Locomotives. St. Paul, Minnesota: Voyageur Press. ISBN 978-0-7603-2396-0.
- Solomon, Brian (2010). Vintage Diesel Power. Minneapolis, Minnesota: MBI Publishing. ISBN 978-0-7603-3795-0.
- Solomon, Brian (2011). Electro-Motive E-Units and F-Units: The Illustrated History of North America's Favorite Locomotives. Minneapolis, Minnesota: Voyageur Press. ISBN 978-0-7603-4007-3.
- Solomon, Brian (2012). North American Locomotives: A Railroad-by-Railroad Photohistory. Minneapolis, Minnesota: Voyageur Press. ISBN 978-0-7603-4370-8.
- Rio Grande Modelling and Historical Society. DRGW EMD F7 Roster. D&RGW F7 diesel roster. Retrieved November 22, 2021, from https://www.rgmhs.org/data/diesels/f7.html.
- 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, Jeff (1999). F Units: The Diesels That Did It. Golden Years of Railroading. Waukesha, Wisconsin: Kalmbach Publishing. ISBN 978-0-89024-374-9.
- 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.
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