Backbone tube chassis is a type of automobile constructionchassis that is similar to thebody-on-frame design. Instead of a two-dimensionalladder-type structure, it consists of a strong tubular backbone (usually rectangular incross section) that connects the front and rearsuspension attachment areas. A body is then placed on this structure. It was first used in the EnglishRover 8hp of 1904 and then the FrenchSimplicia automobile in 1909.[1]
The backbone chassis was extensively developed byHans Ledwinka who used it in greater numbers on theTatra 11 and subsequent vehicles. Ledwinka later used backbone frames with central tubes and axles with swinging driveshafts onTatra trucks, becoming known asTatra-concept.[2][1]
The truck backbone chassis is a design feature of CzechTatra heavy trucks[3] (cross-country, military etc.).Hans Ledwinka used this style of chassis for theTatra 11 car in 1923.[2] He then developed the design on trucks with 6x4 modelTatra 26, which had excellent off-road abilities.
This type of chassis has been used in numeroussports cars. It does not protect againstside collisions, and thus has to be combined with a body that would compensate for this shortcoming.
Examples of cars using a backbone chassis areSimplicia (1910),De Tomaso Mangusta,DMC DeLorean,Lloyd 600,Lotus Elan,Lotus Esprit andEuropa,Škoda Popular,Škoda Rapid,Škoda Superb,Tatra 77,Tatra 87,Tatra 97,Toyota 2000GT andTVR S1. Trucks with a backbone chassis include theTatra 111,Tatra 148 andTatra 815. Some cars also use a backbone as a part of the chassis to strengthen it. Examples include theVolkswagen Beetle, where the transmission tunnel forms a backbone.
TheLocost may appear to be using a backbone in addition to the outerspace frame. However examination shows that, in standard form, it adds negligible stiffness and only serves as a convenient support structure for the sheet metal panels forming thetransmission tunnel. TheTriumph Herald andTriumph Vitesse used a twin flanged box section[4] backbone carrying the main torsional[citation needed] and bending loads, with light channel section side rails to stiffen the body, while theTriumph Spitfire andTriumph GT6 sports cars used only the twin-box section backbone, with separate side members in the body, and rear suspension fore and aft loads were also taken by the floor, not the backbone chassis directly.
