Kato, 31-602, HO Scale, Barber S-2 70 Ton Roller Bearing Truck, 2 per Pack

Barber S‑2 70‑Ton Roller Bearing Trucks
The Barber S‑2 70‑ton roller bearing truck became one of the most widely used freight car trucks in the post‑transition era of North American railroading. Designed as an evolution of earlier solid‑bearing trucks, the S‑2 offered improved reliability, reduced maintenance, and better performance at higher speeds. Its roller bearing design made it a preferred choice for railroads modernizing their fleets from the 1960s onward.

Freight Cars That Commonly Used Barber S‑2 Trucks
The Barber S‑2 70‑ton truck was typically found under:
•     Boxcars – General merchandise service, especially newer 50' and 60' cars.
•     Hopper Cars – Coal, grain, aggregates, and other bulk commodities.
•     Flatcars – Machinery, lumber, and intermodal equipment.
•     Gondolas – Scrap, steel products, and other heavy bulk materials.
Its versatility made it a near‑universal choice for 70‑ton freight cars across many railroads.

Timeline
•     First Used: The Barber S‑2 roller bearing truck entered widespread service in the late 1950s to early 1960s, as railroads transitioned away from solid bearings.
•     Peak Use: Throughout the 1960s–1990s, it became a standard truck for 70‑ton freight cars across North America.
•     Current Use: The S‑2 remains common today under older freight cars still in interchange service, as well as on maintenance‑of‑way equipment and museum rolling stock.

Information about the Kato 31-601 A-3 Truck 
Features a wheel bearing cap that spins as truck is rolling, simultaneously maintaining the vehicle's smooth rolling ability.