EMD SD7
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 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 ' 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 P'urpose. 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 industrial 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..
Many earlier model GPs, most particularly GP40s, GP39s and GP38s, also their SD equivalents, SD40s, SD39s and SD38s have been rebuilt to Dash 2'' standards for another 30 to 40 years of service.
Original buyers
| Owner | Quantity | Numbers | Notes |
| Electro-Motive Division | to Southern Pacific 5308 then 2715 to 1415 ne 1518 | ||
| Electro-Motive Division | 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 | To Burlington Northern same numbers | ||
| Chicago, Burlington and Quincy Railroad | 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 | |||
| Total | 188 |
Preservation
- The first SD7 built by EMD, Southern Pacific 1518, is preserved in operational condition at the Illinois Railway Museum.
- Southern 197 is preserved at the Virginia Museum of Transportation. It was originally built as Central of Georgia 201.
- The Dakota Southern Railway rosters two SD7's, #512, and #522.
- 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 Railroad 8589 is in operation at Red Trail Energy in Richardton ND as 1751 with a chopped nose.
- Nevada Northern Railway 401 is in service at one of LADWP’s power plants in Delta, Utah. When retired, it will be donated to the Nevada Northern Railway Museum, as part of an agreement.