HO SD45T-2 Locomotive, Southern Pacific #9340 Overview
To help combat locomotives overheating in tunnels, SP and EMD developed the SD40T-2 and SD45T-2 models. The âTâ (or Tunnel) refers to the modified design of moving the air intake lower near the rear end walkway to bring in cooler air and thus reducing engine overheating in tunnels. With the success of the EMD SD45, SP ordered the SD45T-2, needing the higher HP to help move heavy freight over the steep grades of Donner and Tehachapi. SP was pleased with the results and ordered over 200 units from 1972 to 1975 becoming part of the backbone of their locomotive fleet.
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 âTunnel Motorsâ 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.