SW1 Diesel Locomotive

Prototype Information

EMD introduced the SW1 in 1938 as a lightweight switcher for light industrial and branch line work. This model marked a pivotal moment for the company because it featured the first 6-cylinder version of the 567 series engine. This prime mover produced 600 horsepower and helped establish EMD’s dominance in the diesel market. Its small size and short wheelbase allowed it to navigate tight curves and light rails that larger locomotives could not handle.

Production of the SW1 spanned 15 years, though World War II temporarily halted construction as the government prioritized larger units. By the time production ended in 1953, EMD had built over 660 units for a wide variety of customers. Railroads valued the SW1 for its longevity and remarkably low operating costs. Many units survived decades of service with their original owners before moving to grain elevators and shortlines. Today, several SW1s remain in active service or reside in museums as examples of early diesel success.