An aside story; mrs kitnut's Dad was in the REME and was posted for a while in the Recovery Unit. He told me he was called out one day to go clean up some mess. Apparently, a prototype Scorpion the Army was testing had been driving very fast down one of the 'M' roads the UK has, when it suddenly shed it's tracks --- the following mayhem cause considerable damage to public vehicles in the vicinity --- Afterwards the Scorpions were fitted with a governor to restrict their speed.