EMD SD7

EMD SD7
SP #1518 inside Barn 9 at the Illinois Railway Museum in Union, Illinois on May 27, 2023.
Type and origin
Power typeDiesel-electric
BuilderGeneral Motors Electro-Motive Division (EMD)
ModelSD7
Build dateMay 1951 – November 1953
Total produced188
Specifications
Configuration:
 • AARC-C
Gauge4 ft 8+12 in (1,435 mm) standard gauge
TrucksEMD Flexicoil C
Wheel diameter40 in (1,016 mm)
Minimum curve23° (250 ft (76.20 m) radius)
Wheelbase48 ft 7 in (14.81 m)
Length61 ft 2+34 in (18.66 m)
Width10 ft 8 in (3.25 m)
Height15 ft 4+12 in (4.69 m)
Loco weight309,000 lb (140,000 kg)
Fuel capacity1,200 US gal (4,500 L; 1,000 imp gal)
Prime moverEMD 16-567B
RPM range800
Engine typeV16 diesel engine
AspirationRoots-type supercharger
Displacement9,072 cu in (148.66 L)
GeneratorD-12-C
Traction motors(6) D-27-B
Cylinders16
Performance figures
Power output1,500 hp (1.12 MW)
Tractive effort77,250 lbf (343,600 N)
Career
LocaleUnited States
DispositionSome still in service, others preserved

The EMD SD7 is a model of 6-axle diesel 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. United States railroads bought 188 units.[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. EMD continues to produce SD series locomotives to this day. Some SD7s both high and short-hood can still be found in service today on shortline railroads and industrial operators, although most Class I roads stopped using these locomotives by the 1970s and 1980s.[2][3]

  1. ^ Pinkepank, Jerry A (1973). The Second Diesel Spotter's Guide. Kalmbach Books. p. 71. LCCN 66-22894.
  2. ^ Guss, Chris (May 16, 2023). "EMD's pioneering SD7 and SD9 locomotives". Trains Newsletter. Kalmbach Media. Retrieved May 16, 2023.
  3. ^ Solomon, Brian (2014). GE and EMD Locomotives: The Illustrated History. Voyageur Press. p. 249. ISBN 978-0-7603-4612-9.