Around here the rules are: - must be approved by the insurance companies (they have a test procedure that IIRC is to have two experienced persons try to break

Around here the rules are: - must be approved by the insurance companies (they have a test procedure that IIRC is to have two experienced persons try to break it using anything up to and including hand held power tools) - must weight 150kgs or - be bolted to the floor from the inside