In railway terminology the term running gear refers to those components of a railway vehicle that run passively on the rails, unlike those of the driving gear. Traditionally these are the

wheel A wheel is a circular component that is intended to rotate 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 machines. Wheels, in conjunction wi ...

axle An axle or axletree is a central shaft for a rotating wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to the vehicle, with the wheels rotating around the axle. In the former case, bearing ...

axle box A bogie or railroad truck holds the wheel sets of a rail vehicle. Axlebox An ''axle box'', also known as a ''journal box'' in North America, is the mechanical subassembly on each end of the axles under a railway wagon, coach or locomotive; ...

es, springs and vehicle frame of a railway

locomotive A locomotive or engine is a rail transport vehicle that provides the Power (physics), motive power for a train. If a locomotive is capable of carrying a payload, it is usually rather referred to as a multiple unit, Motor coach (rail), motor ...

wagon A wagon or waggon is a heavy four-wheeled vehicle pulled by draught animals or on occasion by humans, used for transporting goods, commodities, agricultural materials, supplies and sometimes people. Wagons are immediately distinguished from ...

. The running gear of a modern railway vehicle comprises, in most instances, a

bogie A bogie ( ) (in some senses called a truck in North American English) is a chassis or framework that carries a wheelset, attached to a vehicle—a modular subassembly of wheels and axles. Bogies take various forms in various modes of transp ...

frame with two wheelsets. However there are also wagons with single axles (fixed or movable) and even individual wheels. Since in modern times, locomotives no longer require separate

driving Driving is the controlled operation and movement of a vehicle, including cars, motorcycles, trucks, buses, and bicycles. Permission to drive on public highways is granted based on a set of conditions being met and drivers are required to fol ...

and

carrying axles A carrying wheel on a steam locomotive is a wheel that is not driven; i.e., it is uncoupled and can run freely, unlike a coupled or driving wheel. It is also described as a running wheelWörterbuch der Industriellen Technik, Dr.-Ing. Richard Erns ...

(see

wheel arrangement In rail transport, a wheel arrangement or wheel configuration is a system of classifying the way in which wheels are distributed under a locomotive. Several notations exist to describe the wheel assemblies of a locomotive by type, position, and c ...

), as was formerly common with

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, oil or, rarely, wood) to heat water in the locomot ...

s, but usually have bogies where all axles are driven, the term running gear is (inaccurately) superseding the term 'driving gear' in some parts of the world.

References

See also