The word monocoque is a French term for single shell or (of boats) single hull.[1] 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. By contrast, a semi-monocoque is a hybrid combining a tensile stressed skin and a compressive structure made up of longerons and ribs or frames.
Some tornadoes move faster than some cars (record speed for a tornado moving across land is 72.6 mph (116.8 km/h)), even when the road is clear and flat. Any of these situations can leave drivers stranded in the path of the tornado far from substantial shelter.
A tornado is defined as a violently rotating column of air extending from a thunderstorm to the ground. The most violent tornadoes are capable of tremendous destruction with wind speeds of 250 mph or more. Damage paths can be in excess of one mile wide and 50 miles long. Once a tornado in Broken Bow, Oklahoma, carried a motel sign 30 miles and dropped it in Arkansas!