An SD7 is a 6-axle road switcher diesel-electric locomotive built by General Motors Electro-Motive Division between February 1952 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.[1]
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.[2]
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. However, 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
Preservation
- The Dakota Southern Railway rosters two SD7's, #512 (Believed to be rebuilt from CNOTP F7B #6173), and #522 (Ex-WSOR #522, Exx-MILW #522, Exxx-MILW #2222).
References
- ↑ Pinkpank, Jerry A (1973). The Second Diesel Spotter’s Guide. Kalmbach Books. p. 71. LCCN 66-22894.
- ↑ Ross, David, ed. (2003). The Encyclopedia of Trains and Locomotives. pp. 281, 364, 368–369. ISBN 978-0-7607-9679-5.
- Dorin, Patrick C. (1972). Chicago and North Western Power. 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
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