A roll cage is a specially engineered and constructed frame built in (or sometimes around, in which case it is known as an exo cage) the passenger compartment of a vehicle to protect its occupants from being injured or killed in an accident, particularly in the event of a rollover. == Designs == There are many different roll cage designs depending on the application, hence different racing organizations have differing specifications and regulations, although most of these organisation harmonise their regulations with those of the FIA.[1] Roll cages help to stiffen the chassis, which is desirable...

Monocoque (), also called structural skin, is a structural system in which loads are supported by an object's external skin, similar to an egg shell. The word monocoque is a French term for "single shell" or (of boats) "single hull".First used for boats, a true monocoque carries both tensile and compressive forces within the skin and can be recognised by the absence of a load-carrying internal frame. Few metal aircraft can strictly be regarded as pure monocoques, as they use a metal shell or sheeting reinforced with frames riveted to the skin, but most wooden aircraft are described as monocoques...