The SD40T-2 introduced a modified radiator section on the most successful diesel locomotive of all time to help the railroads of the American west cope with tunnels.
Builder: General Motors, Electro Motive Division (EMD)
AAR Type: CC
Dates Built: 1974 - 1980
Number Built: 312
Length: 70ft 8in
EMD introduced its SD40 model in 1965 as a mid-range general service locomotive. Ironically, the "SD" which originally stood for Special Duty model of the 40 series locomotive was less specialized than the "General Purpose" GP40 which was marketed for fast freight service.
The SD40 was already emerging as the premier locomotive on the rails by the time EMD introduced its "-2" modular electrical package in 1972. This upgrade featured a modular electrical system that was faster and easier to replace and maintain. It was made available on all current EMD production models. Internally nothing else was changed, so EMD simply applied a "-2" suffix to the model number rather than a new designation. The practice ended with the SD and GP50 since the new package was by then standard.
The SD40-2 became the most successful diesel locomotive design of all time, with nearly 4,000 delivered to many railroads all across the United States, Canada and Mexico. Versions were also shipped to Brazil and Guinea. In addition to seeing service in five countries and three continents, the locomotives were also built internationally in the United States (La Grange, IL), Canada (London, Ont.) and in Spain (MACOSA - Valencia).
The SD40-2 featured a turbo-charged 16 cylinder model 645E3 engine and produced 3,000 horsepower. It's principle competition were the C30-7 locomotives from General Electric, although these locomotives never came close to matching EMD's sales numbers. ALCO also offered 3,000 horsepower six axle "Century" class locomotives, the C-630.
Despite the SD40-2's reputation as a reliabl workhorse, railroads in the southwestern United States, particularly the Rio Grande and Southern Pacific, were experiencing mechanical problems on certain routes. The problem was overheating and the cause was determined to be the heat of the air being pulled into the radiator inside the many tunnels along these lines.
Fumes in the tunnels had long been a problem on these routes, causing the Southern Pacific to order special "Cab-Forward" steam locomotives decades earlier. Here the locomotive was reversed, with the cab at the front and the smokebox next to the tender. This kept the crew ahead of the sufficating smoke.
Now it wasn't the crew, but the locomotives that were suffocating in the hot, exhaust filled tunnel air. To solve the problem, EMD's engineers developed a new radiator design with the air intakes located near the walkways at the rear of the carbody.
Although all the other mechanics remained the same, this design change had a radical impact on the look of the locomotive overall. The frame was stretched and the radiator took on a much boxier appearance.
Even among a relatively small group of locomotives like these, there were several production variations based on customer options. These included different sized fuel tanks (4,000 gallons for the Rio Grande, 4,400 for the Southern Pacific and Cotton Belt) and three different size short hoods. These were 81", 88" and 104" (often called "snoots") extended for radio control equipment.
A similar radiator revision was made to the SD45-2 as well. The SD45T-2 was virtually identical to the SD40T-2. This radiator design was also applied univerally to the much smaller GP15.
As was common with many more traditional SD45 and SD45-2s nationwide, the Southern Pacific rebuilt many of its SD45T-2s into SD40T-2 models at their Sacramento, California shops. Many of the locomotives listed on secondary rosters today as SD40T-2s were originally SD45T-2 models.
These locomotives served their original owners well. Eventually, through mergers, all of the remaining units would go to Southern Pacific, and then Union Pacific's roster in 1996. Since then, many have been retired and sold to shortlines all across the country.
Like the much more common standard variety SD40-2, the SD40T-2 has been a resounding success. It looks as if some will continue to ply the rails for more years to come.
Original owners shown in bold.
- Alabama and Tennessee River - 3
- America Latina Logistica - 53
- Boone and Scenic Valley - 1
- Buffalo and Pittsburgh - 2
- Cedar Rapids and Iowa City - 1
- Central Oregon and Pacific - 3
- Denver and Rio Grande - 73
- Fort Worth and Western - 3
- Ferrovia Centro Atlantico (Brasil) - 6 (Rebuilt as BB40T-2)
- GECX - 48
- HLMX - 25
- ILSX - 1
- Indiana and Ohio - 3
- Kansas City Southern - 8
- KLWX - 3
- LTEX - 14
- Missouri and North Arkansas - 1
- Nebraska Northeastern - 1
- New York Susquehanna and Western - 4
- Northern Illinois and Wisconsin - 1
- NREX - 13
- Ohio Central - 2
- Reading and Northern - 1
- RJ Corman - 9
- Squaw Creek Southern - 1
- St. Louis Southwestern (Cotton Belt) - 10
- Southern Pacific - 229
- Terminal RR Association (St. Louis) - 2
- Union Pacific -
- Wheeling and Lake Erie - 2
The SD40T-2 has been produced in several scales. In most cases however, only one version was modeled and has been used to represent total production. Modelers looking for a completely accurate model of specific locomotives may need to do some work to get correct fuel tanks, short hoods and other small details.
The list of models below is specific to just the SD40T-2 itself. Some manufacturers have produced multiple runs capturing several of the common variations.
N Scale: Intermountain, Key (brass, 1990s)
HO Scale: Athearn (produced as a "blue box" model for decades and recently re-released with better tooling and road-specific details)
O Scale: Central Locomotive Works, Lionel, Overland (brass)