Bogie

From Free net encyclopedia

For other uses, see Bogie (disambiguation).

A bogie is a wheeled wagon or trolley. In mechanics, 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.

1 Railway cars
2 Tram Bogies
3 Tracked vehicles
4 External links

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Railway cars

Image:Bettendorf truck at Illinois Railway Museum.JPG Image:Railroad truck,FM55-20.Fig8-8.png Image:Bogie-metro-Meteor-p1010692.jpg A bogie in the UK, or a wheel truck, or simply truck in the U.S., is a structure underneath a train to which wheel axles (and, hence, wheels) are attached through bearings. If they are used there are usually two for each carriage, wagon and locomotive, or alternatively, they are at the connections between the carriages or wagons. The connections of the bogies with the cars allow a certain degree rotational movement around a vertical axis. Most bogies have two axles, but some cars designed for extremely heavy loads have been built with up to five-axle bogies. Heavy-duty cars may have more than two bogies using span bolsters to equalize the load and connect the bogies to the cars.

Usually the train floor is at a level above the bogies. However, for a double decker train this applies only at the bogies: between them the bottom deck can be lower.

See bogies.

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Tram Bogies

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 neeed to pivot on the horizontal axis as well.

Image:Septa PCC car truck.jpg

There are articulated trams with bogies under articulations, they are called Jacobs bogies.

There are low floor trams without (pivoting) bogies and many tramway enthusiasts see them as "retrogarde" steps.

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.

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