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.
Usually a weak tornado will last for just a few minutes and have wind speeds of 100 mph or less. Some tornadoes intensify further and become strong or violent. Strong tornadoes last for twenty minutes or more and may have winds of up to 200 mph, while violent tornadoes can last for more than an hour with winds between 200 and 300 mph! These violent tornadoes are rare in occurrence.