An SD7 is a 6-axle road switcher diesel-electric locomotive built by General Motors Electro-Motive Division between May 1951 and November 1953. It had an EMD 567B 16-cylinder engine producing 1,500 horsepower (1.12 MW) for its six traction motors. 188 were built for United States railroads. Starting in August 1953 a total of 26 SD7s were produced which used either the 567BC engine or the 567C engine. These units are noted on the roster below.
This was the first model in EMD's SD (Special Duty) series of locomotives, a lengthened B-B GP7 with a C-C truck arrangement. The two extra axles and traction motors are useful in heavy, low speed freight service. SD series locomotives are still being produced today, with the SD70 being the most popular example in current production, and with many SD40-2s and rebuilds to SD40-2 specifications, or SD60s still in operation.
Yesterday's Special Duty eventually became today's Standard Duty, and yesterday's General Purpose has become today's Special Purpose ("time" freight and other time-sensitive lading). True GPs were discontinued after the completion of the last GP60 in 1994. Recently intermodal and other fast freights may be hauled by 6 axles locomotives with 4 powered axles, such as the SD70ACe-P4.
Many SD7s both high and short-hood can still be found in service today on shortline railroads and industral operators, although most Class 1 roads stopped using these locomotives by the 1970s and 1980s. Some remain in rebuilt form on some major Class I railroads, as switcher locomotives..
|Electro-Motive Division||to Southern Pacific 5308 then 2715 to 1415 ne 1518|
|to Baltimore and Ohio 760|
|Baltimore and Ohio Railroad||These units were built with the 567BC engine.|
|Bessemer and Lake Erie Railroad|
|Chicago and North Western Railway|
|Chicago, Burlington and Quincy Railroad||322-324 were built with the 567BC engine. To Burlington Northern 6023-6059|
|Chicago, Burlington and Quincy Railroad (Colorado and Southern Railway)||To Burlington Northern same numbers|
|Chicago, Burlington and Quincy Railroad (Fort Worth and Denver Railway)||858-860 were built with the 567BC engine. To Burlington Northern Same numbers.|
|Chicago, Milwaukee, St. Paul and Pacific Railroad||Renumbered 500–523, 2215-2223 were built with the 567BC engine.|
|Central of Georgia Railway|
|Denver and Rio Grande Western Railroad|
|Great Northern Railway||To Burlington Northern 6000-6022|
|Kennecott Copper Corporation|
|Minneapolis and St. Louis Railway||Renumbered 300–301. To Chicago and North Western Railway.|
|Nevada Northern Railway|
|Pennsylvania Railroad||These units were built with the 567BC engine|
|Southern Pacific Company||5321-5323, 5334-5335 were built with the 567C engine|
|Union Pacific Railroad|
- The first SD7 (later converted into an SD7R) built by EMD, former demonstrator #990, Southern Pacific 1518, is preserved in operational condition at the Illinois Railway Museum.
- Central of Georgia 201 or Southern 197 is preserved at the Virginia Museum of Transportation.
- The Dakota Southern Railway rosters two SD7's, #512, and #522 (512 and 522 are ex-MILW #2212 and #2222).
- Burlington Northern #6008, one of the first 20 SD7s to be built in 1952, is preserved and in restoration to its original appearance as Great Northern #558 at the Minnesota Transportation Museum.
Former Pennsylvania RR SD7 8589 is in operation at Red Trail Energy in Richardton ND as 1751 with a chopped nose.
|Wikimedia Commons has media related to EMD SD7 locomotives.|
- Dorin, Patrick C. (1972). Chicago and North Western Power. Burbank, California: Superior Publishing. p. 114. ISBN 0-87564-715-4.
- Pinkpank, Jerry A (1973). The Second Diesel Spotter’s Guide. Kalmbach Books. pp. 17, 26, 71–72. ISBN 0-89024-026-4. LCCN 66-22894.
- Sarberenyi, Robert. EMD SD7 Original Owners. Retrieved on August 27, 2006
- Diesel Era Volume 6 Number 6 November/December 1995, "EMD's SD7" by Paul K. Withers pp 5-20; 47-50.
- EMD Product Reference Data Card dated January 1, 1959 has the 567BC and 567C engine data used in the as-built roster.