Prototype Profile: The EMD SD40/SD40-2

3 CN SD40s

Prototype Profile: The EMD SD40/SD40-2

The EMD SD40/SD40-2 is one of the most – if not THE most – recognizable diesel locomotives in North America. Read on for a bit of history, some photos, and some modeling ideas for this month’s Prototype Profile: The EMD SD40/SD40-2.

3 CN SD40s

A trio of Canadian National SD40s on lease to the L&N in 1984. Photo by Jay T. Thomson, used with permission

The SD40/SD40-2 is a 3,000 horsepower, six-axle locomotive. The SD40 began production in 1966 and remained in production until August 1972. The SD40-2, with upgraded electronics, began production in January 1972 and remained in production until 1989. During those years, well over 5,000 units were produced of the two models combined. Today, several railroads still have SD40s in service – some are older SD40s rebuilt with modern electronics and some are SD40-2s that are basically the same as the day the first entered service.

CSX SD40-3

CSX SD40-3 with CSX-designed “safety cab”. This unit was rebuilt from an older SD40-2. Photo by Jay T. Thomson, used with permission

The Union Pacific and the Missouri Pacific ordered the most SD40s – with 115 and 90 ordered, respectively. Most of those MP units later ended up as Union Pacific units after the UP absorbed them in 1997. For the SD40-2, it was the Burlington Northern and the Union Pacific that ordered the most – with 835 and 686 respectively.

BNSF Sd40-2

A BNSF SD40-2 still wears BN green in 2015. Photo by the author.

The BN SD40-2s became BNSF units and even though BNSF very rarely uses their SD40s in mainline service, many them remain on the roster in service on locals, branch lines, and in yard service.

Southern high short hood sd40

A high short hood Southern Railway SD40. Only Southern and Norfolk and Western ordered SD40s with high short hoods. Photo by Jay T. Thomson, used with permission.

Internal electronics isn’t the only difference between the earlier SD40 and its SD40-2 successor. The ‘dash 2’ models were also considerably longer than the earlier units, leaving them with roomy back and front “porches”. The extra length was to accommodate the brand-new HT-C trucks/bogies, which were larger than the older and visually similar Flexicoil C trucks.

N&W high short hood sd40

A Norfolk & Western high short hood SD40. Most of these units that survived to the Norfolk Southern merger have been rebuilt with low short hoods. Photo by Jay T. Thomson, used with permission

So many SD40s were built and remain in service, that a large number of them have been rebuilt. Some of the rebuilds were done by private rebuilding and leasing companies, such as Alstom or MPI, and the new rebuilds then leased back to various railroads. Other rebuilds were done in-house, such as those by Norfolk Southern, or under contract, such as those by numerous railroads.

MRL SDP40

Montana Rail Link SDP40-2XR is a rebuilt ex-BN SDP40. You can see the extended long hood at the rear of the unit. Photo by the author.

There were a few variants of the SD40 series that were built new, such as the SDP40, SDP40F, SD40T-2, SD40-2W, SD40-2F, and high short hood versions of both the SD40 and SD40-2 for railroads like Southern and Norfolk & Western.

Cottom Belt Tunnel Motor

Cotton Belt, a subsidiary of Southern Pacific, was one of three railroads to own the SD40T-2 (the others being SP and Rio Grande). The “T” stands for Tunnel Motor. These engines were designed with different types of radiator fans for use in the multiple tunnels of the Rockies and Cascades. Photo by Jay T. Thomson, used with permission.

Finally, there are a few custom, in-house variants of the SD40, such as the SD40-2Bs that were rebuilt as cabless booster units from wrecked units by the Santa Fe (and they are still in service on the BNSF today).

CP SD40-2F

Canadian Pacific SD40-2F. The “F” stands for “Full Cowl”. This unit also has the typical Canadian-style safety cab. Photo by the author.

If you model North American mainlines set in any time period from 1966 on, you will probably want to have at least one or two SD40s running on your layout – if not more. Luckily, there are plenty of SD40 and SD40-2 models available for you to chose from!

Amtrak SDP40F

Amtrak SDP40F. Essentially an SDP40 but with a full cowl rear hood and an EMD wide cab. Only Amtrak owned these units. Photo by Jay T. Thomson, used with permission.

Sample SD40 Models Available:

N Scale
Chicago & North Western SD40-2
Illinois Central SD40-2
BNSF SD40-2

HO Scale
CSX SD40-2
Norfolk Southern SD40-2
Norfolk & Western high short hood SD40

O Scale
Clinchfield SD40
Southern Pacific SD40
Baltimore & Ohio SD40

 

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Robert Thomson

Robert W. Thomson is a life-long railfan, the son of a former L&N Railroad B&B gang foreman, and an amateur photographer. He was born and raised in southeast Tennessee but now lives in Butte, Montana with his wife, Connie and cat, Charlie. Robert has worked as a park ranger, underground mine tour guide, freelance roleplaying game writer, and ran his own roleplaying game publishing company until selling it in 2012.

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About The Author

Robert Thomson

Robert W. Thomson is a life-long railfan, the son of a former L&N Railroad B&B gang foreman, and an amateur photographer. He was born and raised in southeast Tennessee but now lives in Butte, Montana with his wife, Connie and cat, Charlie. Robert has worked as a park ranger, underground mine tour guide, freelance roleplaying game writer, and ran his own roleplaying game publishing company until selling it in 2012.