SD45

The EMD SD45 is a 3,600 horsepower (2,680 kW) C-C diesel-electric locomotive built by General Motors Electro-Motive Division (EMD) from 1965 to 1971. It was a high-horsepower locomotive designed for freight service. The SD45 was characterized by its powerful 20-cylinder 645E3 prime mover and its distinctive flared radiators. It was a popular model with many railroads in North America, including the Atchison, Topeka and Santa Fe Railway, Burlington Northern Railroad, and Southern Pacific Transportation Company. Over 1,200 units were produced.

The SD45 was a success in its time, offering a significant increase in horsepower over earlier models. Its robust construction and powerful engine made it suitable for heavy hauling. Many SD45s remained in service for decades, undergoing rebuilds and modifications by various railroads. Some units were later converted to other models, such as the SD45R (rebuilt) or SD45-2. While largely retired from mainline service in North America, some SD45s have been preserved by heritage railways. The SD45 represented a significant step in the evolution of diesel locomotive technology.