SD45T-2 Diesel Locomotive

Prototype Information

The EMD SD45T-2 is a six-axle diesel-electric locomotive built by Electro-Motive Division (EMD) from 1972 to 1975. It belongs to the Dash 2 series and is a modified version of the SD45-2 designed for better cooling in tunnels and mountainous areas. This design earned it the nickname “tunnel motor.”

EMD placed the radiator air intakes low on the body near the walkway. This change allowed the locomotive to draw cooler air inside tunnels, preventing overheating on steep grades.

The SD45T-2 uses a powerful 3,600-horsepower 20-cylinder 645E3 engine, more powerful than the 3,000 horsepower in the SD40T-2. Railroads like Southern Pacific and Denver & Rio Grande Western primarily operated these locomotives.

Although production ended in 1975, many SD45T-2s stayed in service for decades. Railroads rebuilt some units or sold them to smaller carriers. The SD45T-2 earned a reputation for combining high power with effective tunnel cooling.