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 3,000 horsepower (2,240 kW). 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.[1] 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.
EMD SD45T-2 vs SD40T-2 radiator fan motor access doors
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 4,400-US-gallon (16,700 L; 3,660 imp gal) fuel tank and is 70 feet 8 inches (21.54 m) long. Rio Grande's version has a smaller 4,000-US-gallon (15,100 L; 3,330 imp gal) fuel tank.
8300 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.
From 2010 to 2019, Union Pacific #2921 (formerly Southern Pacific #8385) was preserved at the Boone and Scenic Valley Railroad in Boone, Iowa.[4] In 2020, the locomotive was traded to Midwest Locomotive Leasing (MWLX) for general service.Comparison between an EMD SD40T-2 (left) and SD40-2 (right)
