Backbone tube chassis is a type of automobile construction chassis that is similar to the body-on-frame design. Instead of a two-dimensional ladder-type structure, it consists of a strong tubular backbone (usually rectangular in cross section) that connects the front and rear suspension attachment areas. A body is then placed on this structure. It was first used in the English Rover 8hp of 1904 and then the French Simplicia automobile in 1909.
The backbone chassis was extensively developed by Hans Ledwinka who used it in greater numbers on the Tatra 11 and subsequent vehicles. Ledwinka later used backbone frame with central tube and axles with swinging driveshafts on Tatra trucks, became known as Tatra-concept.
ledwwas invoked but never defined (see the help page).