ACF 4600 Covered Hopper

Prototype Information

American Car and Foundry introduced the 4600 cubic foot Center Flow covered hopper in the mid-1960s. This design revolutionized the industry by replacing the heavy traditional center sill with a curved, self-supporting body. This change allowed for a single row of discharge gates centered between the rails, which made unloading much faster and more efficient. ACF specifically designed the 4600 model to meet Plate B clearance standards. This allowed the cars to operate on light branch lines and at older grain elevators where larger jumbo hoppers could not fit.

The ACF 4600 primarily transported agricultural products like grain and corn, though some carried plastic pellets or minerals. Production evolved through several phases. Early versions featured high brake wheels and single side stiffeners, while later models moved the brake wheel lower and added double side stiffeners. Major railroads like the Chicago & North Western, Rock Island, and Burlington Northern operated massive fleets of these cars for decades. Their durable construction and versatility kept many units in revenue service well into the 2000s. Today, these hoppers remain a common sight in maintenance-of-way service or on short-line railroads across North America.