EMD SDP40
Model of 20 North American locomotives
title: "EMD SDP40" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["electro-motive-division-locomotives", "c-c-locomotives", "passenger-locomotives", "diesel–electric-locomotives-of-the-united-states", "railway-locomotives-introduced-in-1966", "standard-gauge-locomotives-of-the-united-states", "standard-gauge-locomotives-of-mexico", "diesel–electric-locomotives-of-mexico", "great-northern-railway-(united-states)-locomotives"] description: "Model of 20 North American locomotives" topic_path: "geography/united-states" source: "https://en.wikipedia.org/wiki/EMD_SDP40" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0
::summary Model of 20 North American locomotives ::
::data[format=table title="Infobox locomotive"]
| Field | Value |
|---|---|
| name | EMD SDP40 |
| image | KCS 3057.jpg |
| caption | Kansas City Southern Railway 3057 |
| powertype | Diesel-electric |
| builder | General Motors Electro-Motive Division (EMD) |
| buildmodel | SDP40 |
| builddate | June 1966 – May 1970 |
| totalproduction | 20 |
| aarwheels | C-C |
| uicclass | Co'Co' |
| Britishclass | Co-Co |
| gauge | |
| trucks | Flexicoil C2L |
| wheeldiameter | 40 in |
| minimumcurve | 57°/274 ft |
| wheelbase | 13 ft |
| truck | 6-Wheel |
| pivotcentres | 53 ft |
| over couplers | 65 ft |
| width | 10 ft |
| height | 15 ft |
| locoweight | 368000 lb |
| fueltype | Diesel |
| fuelcap | 3200 usgal |
| lubecap | 243 usgal |
| coolantcap | 295 usgal |
| watercap | 2200 usgal |
| sandcap | 56 ft3 |
| consumption | 167 usgal per hour |
| watercons | 45 usgal per hour |
| primemover | EMD 16-645E3 |
| rpmrange low | 215 |
| rpmrange idle | 315 |
| rpmrange max | 900 |
| enginetype | V16 Two-stroke diesel |
| aspiration | Mechanically-assisted turbocharger |
| displacement | 10320 in3 |
| alternator | Delco 64-72 |
| generator | Main: GM - D32 |
| Auxilary: GM | |
| tractionmotors | GM - D77 (6) |
| cylindercount | 16 |
| cylindersize | 8.5 in × 10 in |
| transmission | Diesel-electric transmission |
| gear ratio | 59:15 |
| multipleworking | Yes |
| trainheating | Vapor-Clarkson Steam Boiler AR4125 |
| locobrakes | Independent air |
| optional: dynamic brakes | |
| trainbrakes | Westinghouse 26L (Air Brake) |
| maxspeed | 83-95 mph |
| poweroutput | 3000 hp |
| t/e starting | 90000 lbf @25% |
| t/e continuous | 82100 lbf @ 6.6 mph |
| locale | North America |
| :: |
| name = EMD SDP40 | bgcolor = | color = | image = KCS 3057.jpg | alt = | caption = Kansas City Southern Railway 3057 | powertype = Diesel-electric | designer = | builder = General Motors Electro-Motive Division (EMD) | ordernumber = | serialnumber = | buildmodel = SDP40 | builddate = June 1966 – May 1970 | totalproduction = 20 | rebuilder = | rebuilddate = | numberrebuilt = | aarwheels = C-C | uicclass = Co'Co' | Britishclass = Co-Co | DRGtype = | driver = | gauge = | trucks = Flexicoil C2L | bogies = | leadingdiameter = | wheeldiameter = 40 in | trailingdiameter = | carrydiameter = | minimumcurve = 57°/274 ft | wheelbase = 13 ft | wheelspacing = | engine total = | leading = | drivers = | coupled = | trailing = | truck = 6-Wheel | bogie = | tender total = | tendertruck = | tenderbogie = | racksystem = | pivotcentres = 53 ft | length = | over couplers = 65 ft | over headstocks = | body = | over buffers = | width = 10 ft | height = 15 ft | axleload = | leadingbogie/pony= | weightondrivers = | trail bogie/pony = | locoweight = 368000 lb | emptyweight = | serviceweight = | fueltype = Diesel | fuelcap = 3200 usgal | lubecap = 243 usgal | coolantcap = 295 usgal | watercap = 2200 usgal | sandcap = 56 ft3 | powersupply = | consumption = 167 usgal per hour | watercons = 45 usgal per hour | primemover = EMD 16-645E3 | rpmrange = | rpmrange low = 215 | rpmrange idle = 315 | rpmrange max = 900 | enginetype = V16 Two-stroke diesel | aspiration = Mechanically-assisted turbocharger | displacement = 10320 in3 | alternator = Delco 64-72 | generator = Main: GM - D32 Auxilary: GM | tractionmotors = GM - D77 (6) | t/m starting = | t/m amps 1 hr = | t/m amps cont = | headendpower = | cylindercount = 16 | cylindersize = 8.5 in × 10 in | transmission = Diesel-electric transmission | runningsteps = | runningstepswitch = | gear ratio = 59:15 | multipleworking = Yes | trainheating = Vapor-Clarkson Steam Boiler AR4125 | locobrakes = Independent air optional: dynamic brakes | dynamicpeakeffort= | locobrakeforce = | trainbrakes = Westinghouse 26L (Air Brake) | reservoircap = | compressorcap = | exhaustercap = | coupling = | maxspeed = 83-95 mph | poweroutput = 3000 hp | poweroutput start= | poweroutput 1 hr= | poweroutput cont= | powerindex = | tractiveeffort = | t/e starting = 90000 lbf @25% | t/e 1 hr = | t/e continuous = 82100 lbf @ 6.6 mph | factorofadhesion = | f/adh starting = | f/adh 1 hr = | f/adh continuous= | safety = | operator = | operatorclass = | powerclass = | numinclass = | fleetnumbers = | officialname = | nicknames = | axleloadclass = | locale = North America | deliverydate = | firstrundate = | lastrundate = | retiredate = | withdrawndate = | preservedunits = | restoredate = | scrapdate = | currentowner = | disposition = | notes =
The SDP40 is a 6-axle passenger diesel-electric locomotive built by General Motors Electro-Motive Division (EMD) between June 1966 and May 1970.
Design
Like its predecessor in EMD's catalog, the SDP35, the SDP40 is a high-horsepower freight locomotive with equipment for passenger train service.
In 1966, EMD replaced all their production units with those powered by the new 645E-series diesel engine. They included six-axle models SD38, SD39, SD40 and SD45, in addition to SDP40. All had standard components including the frame, cab, generator, trucks, traction motors, and air brakes.
The main difference was the power output: the SD38 produced 2000 hp from a non-turbocharged V16, the SD39 produced 2300 hp from a turbocharged V12, the SD40 produced 3000 hp from a turbocharged V16, and the SD45 produced 3600 hp from a turbocharged V20.
The SD40 and SDP40 were so similar that EMD published common operator's and service manuals to cover both.
At the time, most passenger locomotives needed to provide steam to the passenger cars for heating, cooking, and sometimes cooling. They needed a higher gear ratio for faster running, the graduated-release feature on the air brakes, and type F tightlock couplers to keep equipment together in the event of a derailment. To fit a steam generator to the freight-only SD40, the designers had to move the machinery forward about 2 ft on the frame, add a compartment behind the radiators for the boiler, and divide the fuel tank into fuel and water sections.
Appearance
Earlier passenger diesel locomotives, like EMD E8, ALCO PA, FM Erie-built and Baldwin Sharknose locomotives, were streamlined cab units designed for visual appeal and the appearance of speed. The SDP40 and the SDP35 & SDP45 instead have the same appearance as their freight counterparts. This look was contemporary to, and eventually overtaken by cowl units like the GE U30CG and EMD FP45, SDP40F and F40PH.
Visually, the locomotive is a hood unit distinguished only by the shape of its rear end behind the radiators, with its flat end having no number boards, shuttered boiler air intake on each side, extra exhaust stacks over the boiler, cantilevered walkway around the flat end, and very steep rear steps. EMD applied this same end to the passenger SDP35, SDP45, and GP40P locomotives, as well as the freight DD35, DDA40X and SD40T-2.
Amtrak's SDP40F locomotive, although sharing several mechanical specifications, is visually a much different locomotive. Seven years separate their introductions, and the SDP40F was actually based on the SD40-2. It had a full-width carbody, similar to the FP45, and was also 6 ft longer than the SDP40, but was not successful after a series of derailments, which made the F40PH succeed the SDP40F.
Original owners
Great Northern Railway (GN) purchased the first six SDP40s in 1966, to replace older E-units on their Western Star and smaller regional trains. Options included a Vapor OK-4740 steam generators, water-transfer capability between units, 59:18 gearing for a top speed of 83 mph, and Type-F couplers. These were followed in 1967 by eight more powerful SDP45 3,600 hp locomotives ordered for the Empire Builder. After the startup of Amtrak in 1971, Great Northern's successor Burlington Northern Railroad (BN) converted the locomotives to freight service.
One SDP40, former GN 323, was temporarily renumbered BN #1976 and painted in elaborate red, white and blue colors for the United States Bicentennial in 1976.
NdeM had ten units delivered in 1968 and another four in 1970. In 1998, the government of Mexico privatized the NdeM locomotives. These locomotives were split between two successor companies. Eight went to TFM, which was later purchased by Kansas City Southern Railway and became KCSM. Of those eight, two were rebuilt to SD22ECOs, and the other six were scrapped. The remaining six went to Ferromex. Of those six, four were rebuilt to SDP40-2s and remain in service, the other two were scrapped.
Roster
::data[format=table]
| Railroad | Numbers | Comments | Totals | 20 |
|---|---|---|---|---|
| Great Northern Railway | 320-325 | 325 donated to the Minnesota Transportation Museum | ||
| Ferrocarriles Nacionales de México | 8522-8535 | |||
| :: |
Preservation
::figure[src="https://upload.wikimedia.org/wikipedia/commons/f/f8/Great_Northern_325.jpg" caption="Great Northern 325 in September 2023"] ::
BNSF Railway donated #6327 - former Great Northern #325 and their last SDP40 in service - to the Minnesota Transportation Museum in May 2009. Since then, it has been in service on the Osceola and St. Croix Valley Railway. In 2023, the museum repainted the locomotive into the Great Northern's simplified orange and green color paint scheme.
References
Sources
- Shine, Joseph W. (1992). Great Northern Color Pictorial - Volume 2: Division Assignment, Second Generation Diesels, The Big Sky Blue Era. La Mirada, CA: Four Ways West Publications.
- Strauss, John F. Jr. (1998). Great Northern Color Pictorial - Volume 5: Rocky's Robe of Many Colors. La Mirada, CA: Four Ways West Publications.
- The UNofficial EMD Homepage. Retrieved on May 1, 2009
- Sarberenyi, Robert. EMD's SD40, SD40A, and SDP40 - Original Owners. Retrieved on May 5, 2009
- Great Northern Empire - GN EMP SDP40 Roster. Retrieved on May 5, 2009
- KCS NAFTA Rosters. Retrieved on May 5, 2009
- Service Department (1966). SD40 - SDP40 Operator's Manual. La Grange, IL: Electro-Motive Division of General Motors Corporation
- EMD SD 6 WHEEL TRUCKS-DATA. Retrieved on July 25, 2010
References
- (24 February 2023). "Minnesota museum to repaint Great Northern diesel".
- (2023-06-01). "Repainting of Great Northern SDP40 completed".
::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::