EMD SD40T-2

An SD40T-2 is a 6-axle road switcher diesel-electric locomotive built by General Motors Electro-Motive Division having a 16-cylinder EMD 645E3 diesel engine producing 3,000 horsepower (2,240 kW). 312 SD40T-2s were built for North American railroads between April 1974 and July 1980. This locomotive and the SD45T-2 are popularly called tunnel motors, but EMD's term is SD40-2s 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 intakes and radiator fan grills located at the rear of the locomotive.

EMD SD45T-2 vs SD40T-2 radiator fan motor access doors

EMD SD40T-2
SP 8238, eastbound at Caliente, California, in the late 1980s
Type and origin Power type Diesel-electric Builder General Motors Electro-Motive Division Build date June 1974 – July 1980 Total produced 312
Specifications Configuration: ​  • AAR C-C Gauge 4 ft 8 1⁄2 in (1,435 mm) standard gauge Length 70 ft 8 in (21.54 m) Width 10 ft 3 in (3.12 m) Height 15 ft 7.5 in (4.763 metres) Loco weight 368,000 lb (167,000 kg) Fuel capacity 4,400 US gal (16,700 l; 3,660 imp gal) Prime mover EMD 645E3 Engine type V16 diesel Cylinders 16
Performance figures Power output 3,000 hp (2,240 kW) Tractive effort 409 kN (92,000 lbf) (starting) 365 kN (82,000 lbf) (continuous)
Career Operators Southern Pacific (and Cotton Belt), Rio Grande, Union Pacific Nicknames "tunnel motors" Locale western United States Disposition most still in service as of 2010

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.

In 2005, most of these units were owned by Union Pacific or leasing companies. By 2008, none were left in service on UP with SP or DRGW reporting marks.[2] DRGW 5371 was the last one, retired in March 2008, and now resides at the Utah State Railroad Museum in Ogden Utah. Another SD40T-2 is preserved at the Boone & Scenic Valley Railroad in Boone, Iowa, and in late 2017, it was announced that another Rio Grande SD40T-2 was going to be donated to the Colorado Railroad Museum in Golden, Colorado. On August 22, 2018, UP 9871 (formerly D&RGW 5401) was moved to the museum grounds, and was since “unpatched”, painted to resemble its original appearance from 1980, which included painting the number back to 5401. Three former Rio Grande units, 5391, 5413,and 8795, are still active on the Wheeling and Lake Erie Railroad out of Brewster, Ohio.