The EMD SD9[1] is a model of
diesel locomotive built by
General Motors Electro-Motive Division between January 1954 and June 1959. An
EMD 567C 16-
cylinder engine generated 1,750 horsepower (1.30 MW). Externally similar to its predecessor, the
SD7, the SD9 was built with the improved and much more maintainable 567C engine.
Four hundred and seventy-one SD9s were built for
American railroads, while a further 44 were produced for export.
Many SD9s 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.[citation needed]
History
The SD9 was the second model of EMD's SD (special duty) line of locomotives, following the SD7. Just as the SD7 was a lengthened
GP7 with two additional axles, the SD9 was a corresponding modification of the
GP9. The additional axles in SD series locomotives provide more tractive effort and more even distribution of locomotive weight compared to the four axle GP series locomotives.[2]
SD9s can be distinguished from the similar looking SD7s by observing the position of the classification lights on the ends of the locomotive, above the number board. The SD9's classification lights are on a small pod, canted outward, while the SD7's classification lights are closer to the centerline and flush with the hood.[3]
The last phase of construction had a carbody similar to the
SD18 and
SD24, and used two 48-inch (1,219 mm) cooling fans instead of four 36-inch (914 mm) cooling fans.
EMD ended SD9 production in June 1959. It was succeeded by the
SD18 which began production in 1960.
Variants
SD9s
EMD produced a lightweight variant of the SD9, named the SD9s. This locomotive had its weight reduced for service on lighter tracks with modifications such as a smaller fuel tank.[3]
Between August 1970 and March 1980, the
Southern Pacific Transportation Company had rebuilt 144 of their units into
EMD SD9Ediesel locomotives under their own rebuild program known as the General Rehabilitation and Improvement Program (G.R.I.P) and renumbered 142 of their rebuilt units as 4300-4441 and two additional rebuilt units being renumbered as 4450 and 4451, as well as reclassifying their 142 units as EF618E-1 and classified their two units #4450 and #4451 as EF618E-2, which had left six other SD9 locomotives un-rebuilt.[4][5]
BNSF #1552 is stored on the now-defunct
Blackwell Northern Gateway Railroad in Oklahoma, intended for preservation. It is classified as an SD9-3.
BNSF #6125 (ex-GN #598) is preserved at the Inland Northwest Rail Museum at
Reardan, Washington, having been donated in 2020. It is being restored into its original
Great Northern appearance.
Great Northern #599 is preserved by the Inland Northwest Rail Museum in
Reardan, Washington. It will undergo a cosmetic restoration, with mechanical parts used for the restoration of #598. [7]
KORAIL 5025 is only preserved SD9 in Korea, plinthed in front of
Daejeon MPD [
ko], along single
G12 4102. Both engines worked for construction of
KTX Gyeongbu section as departmental vehicles upon retirement of KORAIL.
Norfolk and Western #2349 (ex-NKP #349) is preserved at the Mad River & Nickel Plate Railroad Museum. It was donated to the museum in December 2010 by
Norfolk Southern.
Southern Pacific #5399 is preserved on the
Albany & Eastern Railroad (AERC). Restored to SP's "Black Widow" paint scheme, it is used for both freight and passenger service.