We will explore the key players in the U.S. freight train market and the representative locomotive models they operate.

Freight railroads in the U.S. serve as a massive logistics artery, and understanding the major operators and types of locomotives helps to paint a big picture of rail logistics.

Major Freight Railroad Operators

The U.S. freight railroads are led by seven large companies classified as 'Class I' based on size and revenue.

They own vast rail networks and locomotives and handle 94% of the national freight volume.

  • BNSF Railway: Operates a network of 32,500 miles across the West, Midwest, and South 

  • Union Pacific Railroad: Focused on the West and Midwest, operating 32,100 miles of rail 

  • CSX Transportation: Covers parts of the East and Eastern Canada

  • Norfolk Southern Railway: Network across the Eastern U.S.

  • Canadian National Railway (Grand Trunk): Active in areas adjacent to the northern U.S. border

  • Canadian Pacific Kansas City (CPKC): Owns routes connecting Canada and Mexico

  • Kansas City Southern Railway: Operates routes connecting the Midwest and Northern Mexico

In addition, there are regional Class II and III railroads, but Class I dominates in terms of freight volume and revenue.

Representative Locomotive Models

The common diesel-electric locomotives operated by Class I companies include the following.

  1. GE Evolution Series (ES44 models)

    • Multiple models by transmission type, including ES44AC and ES44DC

    • Versions that meet Tier 2 and Tier 4 emissions regulations exist

    • Optimized for long-haul freight with 4,400 horsepower 

  2. EMD SD70 Series

    • Derivative models such as SD70M, SD70MAC, and SD70ACe

    • 4,000 to 4,300 horsepower, enhanced tractive effort with A.C. traction motors

    • Widely used in Class I railroads and large single-track railroads 

  3. EMD SD40-2

    • 3,000 horsepower, a bestseller produced from the 1960s to the 1980s

    • Almost all railroads have a few, popular in the used market

  4. High-output powerhouses: GE AC6000CW & EMD SD90MAC

    • AC6000CW: 6,000 horsepower, maximum tractive effort of 840 kN

    • SD90MAC: 5,000 to 6,000 horsepower, 890 kN tractive effort

    • Intermittently used for heavy freight train long-distance transport

  5. GP·BL Series and Switchers

    • EMD GP38, GP9, etc., four-axle general-purpose road switchers

    • Used for distributing freight in single-track, mountainous, and industrial lines

U.S. freight railroads are led by Class I large companies, with the GE Evolution series and EMD SD70 series being the most widely operated.

Legacy models like the SD40-2 and AC6000CW can still be seen in various locations. These locomotives are selected and deployed considering each railroad's transportation strategy, emissions regulation compliance, and maintenance costs.

In the future, the locomotive lineup will continue to evolve in line with the trends of enhancing efficiency and eco-friendliness in rail logistics.