The SD40T-2 is a model of diesel-electric locomotive built by General Motors Electro-Motive Division in the United States. The SD40T-2 is equipped with a 16-cylinder EMD 645E3 diesel engine producing . 312 SD40T-2s were built for three railroads in the United States between April 1974 and July 1980. This locomotive and the SD45T-2 are popularly called tunnel motors, but EMD's term is SD40-2 with "cooling system modifications" because they were designed for better engine cooling in mountainous areas. The difference between this locomotive and its non-tunnel motor cousin, the SD40-2, are the radiator air intakes are located lower down at the rear of the locomotive.
This locomotive model was purchased by the Denver and Rio Grande Western Railroad, the Southern Pacific Railroad, and its subsidiary Cotton Belt. Southern Pacific's version has a fuel tank and is long. Rio Grande's version has a smaller fuel tank.
Original purchasers Railroad Quantity Road numbers NotesDenver and Rio Grande Western Railroad735341-5413All with 81 in. or 88 in. short noses.St. Louis Southwestern Railway (Cotton Belt)108322-8326, 8372-8376"snoot noses"Southern Pacific Railroad2298230-8299, 8300-8321, 8327-8341 8350-8371, 8377-8391, 8489-85738300 series featured extended "snoot" noses for radio control equipment. 8278 was damaged beyond repair in the 1989 Cajon Pass runaway and sold for parts, then scrapped.Totals 312
Preservation Denver and Rio Grande Western #5371 is preserved at the Utah State Railroad Museum in Ogden, Utah.
Denver and Rio Grande Western #5392 will be preserved at the city of Helper, Utah, as of 8/17/2026, donated by Genesee & Wyoming's Missouri and Northern Arkansas Railroad.
Denver and Rio Grande Western #5401 is preserved at the Colorado Railroad Museum in Golden, Colorado.
From 2010 to 2019, Union Pacific #2921 (formerly Southern Pacific #8385) was preserved at the Boone and Scenic Valley Railroad in Boone, Iowa. In 2020, the locomotive was traded to Midwest Locomotive Leasing (MWLX) for general service.
Southern Pacific #5387 (formerly Denver and Rio Grande Western #5387) is preserved at the Midwest Overland Rail Preservation Society in Kansas City, Missouri
References
External links
fi:EMD SD40#EMD SD40T-2