EMD SD40T-2

EMD SD40T-2

SP 8238, eastbound at Caliente, California, in the late 1980s
Power type	Diesel-electric
Builder	General Motors Electro-Motive Division
Build date	April 1974 – July 1980
Total production	312
AAR wheel arr.	C-C
Gauge	4 ft 8½ in (1435 mm)
Length	70 ft 8 in
Fuel capacity	4,400 gallon
Prime mover	EMD 645E3
Cylinders	16
Power output	3,000 hp
Career	Southern Pacific (and Cotton Belt), Rio Grande, Union Pacific
Nicknames	"tunnel motors"
Locale	western United States
Disposition	most still in service as of 2005

An EMD SD40T-2 is a 6-axle diesel locomotive built by General Motors Electro-Motive Division. Power is provided by a 16-cylinder EMD 645E3 diesel engine capable of producing 3,000 horsepower. The Southern Pacific's locomotive features a 4,400 gallon fuel tank and is 70 feet 8 inches long. The Rio Grande's locomotive features a smaller 4000 gallon fuel tank. A total of 312 examples of this locomotive were built for North American railroads between April 1974 and July 1980. This locomotive, along with the SD45T-2, are called tunnel motors, since they were specifically designed to be more effective when operating in tunnels. The major differences 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. The radiator air intakes in this model were located along the deck to allow fresher, cooler air to enter and less soot and hot exhaust fumes lingering around the tunnels ceiling.

This locomotive model was purchased by the Southern Pacific Railroad, its subsidiary Cotton Belt, and the Denver and Rio Grande Western Railroad. At one point Southern Pacific and then later Union Pacific Railroad owned every SD40T-2. As of 2005 most of these units are in service on the Union Pacific or various leasing companies. Only one with SP reporting marks and one with DRGW reporting marks are left.

Original purchasers

Railroad	Quantity	Road numbers	Notes
Denver and Rio Grande Western Railroad	73	5341-5413	All with 81 in or 88 in short noses.
St. Louis Southwestern Railway	10	8322-8326, 8372-8376	"snoot noses"
Southern Pacific Railroad	229	8230-8299, 8300-8321, 8327-8341 8350-8371, 8377-8391, 8489-8573	8300 series featured extended "snoot" noses for radio control equipment.