EMD SD40T-2

The EMD SD40T-2 is a type of high-powered, six-axle, 3,000 hp diesel locomotive built specially for the Southern Pacific (including the SSW) and Rio Grande (DRGW) US Class 1 railroads from 1974 to 1980.
It is a modified version of the SD40-2 (as stated in an EMD owner's manual), and was originally an experimental model, it came to be known as a "tunnel motor", due to its large air intake vents placed on the sides of the overall body or along the carbody of the actual locomotive, and was used for cooling the engines while traveling through tunnels up steep mountain grades.
Many still exist but are no longer used or seen on the Union Pacific (the only owner which owned a large fleet as a result of the acquirement of the SP and D&RGW) as of 2009, although the last units were officially retired in 2010.
Many currently operate on various shortlines (including rebuilt and non-rebuilt SD45T-2 units; which were rebuilt as a result of engine issues).
D&RGW #5371 currently resides at the Utah Railway Museum in Ogden, Utah. Another D&RGW SD40T-2 was recently donated to the Colorado Railroad Museum in Golden, Colorado, where it has been cosmetically restored.
Sometime around 2009, the Boone & Scenic Valley Railroad in Boone, Iowa acquired a former Southern Pacific SD40T-2 from the Union Pacific. It was later sold off, as the locomotive was presumably too big or not economical to operate on a regular basis. 
As of 2024, there are no Southern Pacific SD40T-2s in preservation anywhere.
==History==
During the 1970's, six-axle diesel locomotives were in high demand on US Class 1 railroads throughout the United States, and the most desperate of them all, were the Southern Pacific (aside from the SSW subsidiary of the SP) and Rio Grande railroads; who began to wear their aging four-axle diesel locomotives and were in desire need of stronger and more powerful six-axle diesel locomotives that wouldn't overheat so easily like the original SD40-2 and subsequent SD45. Hence, EMD's solution to inventing a revolutionary and advanced cooling system equipped on an actual unit known as a "tunnel motor", which was able to be used on SD40-2 units; thus, the creation of the EMD SD40T-2 (the "T" meaning "tunnel motor").
The EMD SD40T-2 was an initial success, and even inspired the development for the SD45T-2, as well as the GP15T and GP15-1 typ
The SD40T-2 survived well past the merger of the UP and SP up until 2009; as well as the remainder of the D&RGW still having SD40T-2 units left in their original paint existing as of today. (Yet, most former SP and D&RGW units are commonly seen in scrap yards and on shortlines; including those repainted into UP paint.)
==Identification==
There is often a confusion between the SD40T-2 and SD45T-2.
The main external differences between the SD40T-2 and SD45T-2 are the number of radiator fan access doors, located above the radiator intakes; 2 for SD40T-2s and 3 for SD45T-2s.
==Trivia==
*DFTR #2003 is a former SP SD45T-2 fitted with an EMD SD70MAC cab used for crash test experiments for Operation Lifesaver and various other safety companies.
*SSW #9389; an SD40T-2 from the SSW portion of SP's; roster was painted in an exclusive bicentennial scheme in 1976 to commemorate the 200th Anniversary of the United States.
*The Clinchfield Railroad placed an order for SD40T-2s some time in the early 70s, but the order was cancelled at the last minute due to the Family Lines merger. This would have made them the only Eastern railroad purchase the SD40T-2 firsthand.
*The GP15T-1 is often nicknamed the "baby Tunnel Motor" by railfans and train enthusiasts.
*The UP originally intended on ordering a fleet of "Tunnel Motor" units but received former MP (Missouri Pacific) GP15-1 and GP15T units after the MP's purchase.
*The UP had the smallest fleet of "Tunnel Motor" units (consisting of their former MP GP15-1 units) before the purchase SP and D&RGW; to which their fleet doubled in size but have all since been retired even before all units were renumbered or repainted (excluding their former MP GP15 units which still serve as designated yard units).
*The Bessemer And Lake Erie shortline railroad (owned by CN as of 2008-2009) owns a fairly large fleet of rebuilt SD40T-3 units which are actually rebuilt from various SD45T and SD40T units once owned by the SP.
== Gallery ==
File:EMD SD40T-2 UP 2935.jpg
File:8278 sp-sd40t-2 bob dengler.jpg
Category:Diesel locomotives
Category:EMD locomotives
Category:Tunnel Motor
Category:Six-axled diesel locomotives
Category:American locomotives
Category:DC Traction Locomotives
Category:Southern Pacific locomotives
Category:Union Pacific locomotives
Category:Rio Grande locomotives
Category:C-C locomotives
Category:Bessemer and Lake Erie locomotives
Category:Locomotives