Boxpok

A Boxpok wheel is a type of railway wheel characterized by its distinctive spoked design. Unlike solid wheels, Boxpok wheels feature a series of hollow, box-section spokes radiating from the central hub to the outer tire. This construction offers several advantages, primarily in terms of weight reduction and improved stress distribution.

The hollow spokes allow for a lighter wheel compared to a solid design of comparable strength. This reduction in weight is beneficial in reducing unsprung mass, which can improve ride quality and reduce wear on both the track and the rolling stock.

Furthermore, the box-section spokes are designed to better distribute stress concentrations caused by the significant forces experienced during train operation, particularly acceleration, braking, and impacts from track irregularities. This improved stress distribution can lead to increased wheel life and reduced maintenance.

Boxpok wheels are commonly found on steam locomotives and other heavy railway vehicles where their benefits outweigh the more complex manufacturing process compared to solid wheels. The name "Boxpok" is often considered a proprietary term, though it has become a generally recognized descriptor for this type of spoked wheel. They represent a design evolution aimed at optimizing performance and reliability in railway applications.