The SD45T-2 is a six-axle diesel electric locomotive built by General Motors Electro-Motive Division having a 20-cylinder 645-series diesel engine producing 3600 horsepower. Over 200 examples were produced between 1972 and 1975. This locomotive including the SD40T-2 were nick-named “Tunnel Motors” due to the rear cool air intake lowered to just above the walkway at the rear of the locomotive. This helped provide cooler air into the locomotive’s radiator cooling system and ultimately reducing the chance of the engine overheating in tunnels.