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.
The only evidence indicating the wind speeds found in the tornado was the damage left behind by tornadoes which struck populated areas. Some believed they reach 400 mph (640 km/h); others thought they might exceed 500 mph (800 km/h), and perhaps even be supersonic.