English

Noun

bogies

1. Plural of bogie

A bogie () (BŌ-gē) is a wheeled wagon or trolley. In mechanics terms, a bogie is a chassis or framework carrying wheels, attached to a vehicle. It can be fixed in place, as on a cargo truck, mounted on a swivel, as on a train carriage or locomotive, or sprung as in the suspension of a caterpillar tracked vehicle.

Railway

A bogie in the UK, or a wheel truck, or simply truck in the USA, is a structure underneath a train to which axles (and, hence, wheels) are attached through bearings.

Bogies serve a number of purposes:

• To support the rail vehicle body
• To run stably on both straight and curved track
• Ensure ride comfort by absorbing vibration, and minimizing centrifugal forces when the train runs on curves at high speed
• Minimize generation of track irregularities and rail abrasion

Usually two bogies are fitted to each carriage, wagon or locomotive, one at each end. An alternate configuration often used in articulated vehicles, which places the bogies under the connection between the carriages or wagons.

Most bogies have two axles as it is the simplest design,

Only a very small amount of MK1 stock was fitted with the B4 bogie from new, it being used on the MK1 only to replace worn out B1 bogies. The BR MK2 coach however carried the B4 bogies from new. A heavier duty version, the B5, was standard on Southern Region Mk1 based EMUs from the 1960s onwards. Some of the B4 fitted Mk2s, as well as many B4 fitted Mk1 BGs were allowed to run at 110 mph with extra maintenance, particularly of the wheel profile, and more frequent exams.

The BT10 Bogie

The BT10 bogie was introduced on the British Rail Mark 3 coach in the 1970's. Each wheel is separately connected to the bogie by a swing-arm axle.

There is dual suspension:

• primary suspension via a coil spring and damper mounted on each axle.
• secondary suspension via two air springs mounted on the pivot plank. This is connected to the bogie by pendulum links. A constant coach height is maintained by air valves.

Tramway

Tram bogies are much simpler in design because of lighter axle load, this and tighter curves that are found on tramways means that tram bogies almost never have more than two axles. Furthermore, some tramways also have steeper gradients and vertical as well as horizontal curves, which means that tram bogies often need to pivot on the horizontal axis as well.

Some articulated trams have bogies located under articulations, a setup referred to as a Jacobs bogie. Often low floor trams are fitted with non-pivoting bogies and many tramway enthusiasts see this as a retrograde step.

Tracked vehicles

Some tanks and other tracked vehicles have bogies as external suspension components (see armoured fighting vehicle suspension). This type of bogie usually has two or more road wheels and some type of sprung suspension to smooth the ride across rough terrain. Bogie suspensions keep much of their components on the outside of the vehicle, saving internal space. Although vulnerable to antitank fire, they can often be repaired or replaced in the field.

Hybrid systems

Rubber-tyred metro trains utilise a specialised version of railway bogies. As well as the standard running wheels (rubber instead of steel) there are additional horizontal guide wheels in front of and behind the running wheels.

See also

• AAR type A switcher truck
• Blomberg B
• Jacobs bogie
• Rocker-bogie
• Wheel and axle
• Wheel arrangement
• Wheelset

References

External links

• TRUCK (bogie) with tyres
• Arbel Faufet Rail Bogies
• Bogie with tyres
• Track modelling