A Boxpok is a

steam locomotive A steam locomotive is a locomotive that provides the force to move itself and other vehicles by means of the expansion of steam. It is fuelled by burning combustible material (usually coal, Fuel oil, oil or, rarely, Wood fuel, wood) to heat ...

wheel A wheel is a rotating component (typically circular in shape) that is intended to turn on an axle Bearing (mechanical), bearing. The wheel is one of the key components of the wheel and axle which is one of the Simple machine, six simple machin ...

that gains its strength through being made of a number of box sections rather than having traditional solid

spoke A spoke is one of some number of rods radiating from the center of a wheel (the hub where the axle connects), connecting the hub with the round traction surface. The term originally referred to portions of a log that had been riven (split ...

s (the name is a variation on "box-spoke"). Being hollow, they allow better

counterbalancing A counterweight is a weight that, by applying an opposite force, provides balance and stability of a mechanical system. The purpose of a counterweight is to make lifting the load faster and more efficient, which saves energy and causes less wear ...

and stability than conventional drivers, which is important for fast locomotives. The Boxpok wheel was patented by

General Steel Castings General Steel Industries, Inc. (GSI) was an American steel company that operated independently from 1928 to 1981. It was founded by two locomotive manufacturers and a foundry as General Steel Castings Corporation in Eddystone, Pennsylvania. The ...

Corporation of Granite City,

Illinois Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. It borders on Lake Michigan to its northeast, the Mississippi River to its west, and the Wabash River, Wabash and Ohio River, Ohio rivers to its ...

Other wheels

The Boxpok was the most common of the four disk wheels in use by US steam locomotive designers, the others being the Baldwin and Scullin. A fourth design, the Universal, was used in locomotive rebuilds. All vary slightly in appearance but are essentially the same in structure. The term "Boxpok" is also sometimes used to describe the

Bulleid Firth Brown The Bulleid Firth Brown wheel (BFB) was a locomotive wheel developed for the Southern Railway (UK), Southern Railway in the late 1930s. It was a disc wheel, in contrast to the usual spoked wheels in general use on British railways. The wheel was ...

(BFB) wheel in use on British railways at that time, but this is incorrect; while the BFB is similar to the Boxpok, one side of each box section is left open, so is not a true box structure unlike the Baldwin, Boxpok and Scullin drivers.

References

* Train wheels {{Steam-loco-stub de:Eisenbahnrad#Boxpok-Räder

Other wheels

See also

References