# EMD SD9

The EMD SD9 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.
471 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.

## 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.
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.
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.

### SD9E

Between August 1970 and March 1980, the Southern Pacific Transportation Company had rebuilt 144 of their units into EMD SD9E locomotives under their own rebuild program known as the General Rehabilitation and Improvement Program (G.R.I.P). 142 of their rebuilt units were renumbered as 4300-4441 and two additional rebuilt units being renumbered as 4450 and 4451. These 142 units were also reclassified as EF618E-1, with their two units #4450 and #4451 as EF618E-2, which had left six other SD9 locomotives un-rebuilt.

### SD9m

The SD9m was a rebuild from SD7s and SD9s mostly by Norfolk Southern Railway. NS rebuilt a total of ten units and used them in service between 1989 and 2010.

## Original buyers

| Railroad | Quantity | Road numbers | Notes |
| Electro-Motive Division (demonstrator) | 1 | 5591 | to Duluth, Missabe and Iron Range 110 |
| Atlanta and St. Andrews Bay Railroad | 3 | 503–505 | |
| Baltimore and Ohio Railroad | 10 | 765–774 | |
| Chicago, Burlington and Quincy Railroad | 80 | 325–374, 430–459 | 300s had steam generators. To Burlington Northern 6127-6206 |
| Chicago, Burlington and Quincy Railroad (C&S) | 23 | 820–842 | To Burlington Northern 6215-6237 6234 preserved |
| Central of Georgia Railway | 6 | 202–207 | |
| Chicago and Illinois Midland Railroad | 5 | 50–54 | |
| Chicago and North Western Railway | 14 | 1701–1710, 1721–1724 | Fitted for Chicago commuter service |
| Chicago, Milwaukee, St. Paul and Pacific Railroad | 14 | 2224–2237 | Renumbered 530-543 |
| Chile Exploration | 5 | 901–905 | Track gauge? |
| Duluth, Missabe and Iron Range Railroad | 73 | 101–109, 111–174 | 129–130 had steam generators |
| Denver and Rio Grande Western Railroad | 10 | 5305–5314 | |
| Elgin, Joliet and Eastern Railway | 3 | 600–602 | |
| Great Northern Railway | 27 | 573–599 | To Burlington Northern 6100-6126 |
| Korail (Korea) | 29 | 101–129 | Later renumbered 5001-5029 |
| New York, Chicago and St. Louis Railroad (“Nickel Plate Road”) | 20 | 340–359 | |
| Orinoco Mining (Venezuela) | 10 | 1011–1020 | |
| Pennsylvania Railroad | 25 | 7600–7624 | |
| Reserve Mining | 6 | 1220–1225 | To Escanaba and Lake Superior Railroad |
| Soo Line (Wisconsin Central Railroad) | 1 | 2381 | |
| Southern Pacific Company | 150 | 5340–5444, 5449–5493 | 5340–5391 had steam generators |
| Total | 515 | | |

## Preservation

Some SD9 locomotives can be found in museums and on tourist lines, and at least two are in service on a working railroad.
* BNSF #1550 is preserved at the Lake Superior Railroad Museum, having been donated by BNSF in 2022. 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.
* Burlington Northern #6139 is preserved and operational on the Oregon Coast Scenic Railroad.
* Burlington Northern #6234 (ex-Colorado & Southern #839) is preserved and operational at the Minnesota Transportation Museum. It now operates on the museum's Osceola and St Croix Valley Railway. #6234 is an example of the last variation of SD9 locomotives produced, which used the SD18 carbody.
* 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.
* 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 Korea Train Express Gyeongbu section as departmental vehicles after their retirement on Korail.
* Milwaukee Road #532 is preserved and operational at the Whitewater Valley Railroad.
* Nevada Northern Railway #204 (ex-SP #4426) is preserved and operational at the Nevada Northern Railway Museum in Ely, Nevada, and will soon be repainted and renumbered to #250 to celebrate the United States Semiquincentennial in 2026.
* Nickel Plate Road #358 is preserved and operational at the Fort Wayne Railroad Historical Society. It has been restored into its original appearance.
* 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.
* Portland and Western Railroad #1854 is stored in Albany, Oregon. It was retired in February 2024.
* Southern Pacific #4404 is preserved on the Pend Oreille Valley Railroad in Usk, Washington.
* 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.
* Southern Pacific #5472 is preserved and operational on the Niles Canyon Railway