Definitions for "Hedgehogs"
Chain Hedgehogs: these are light weight road barriers consisting of two tripods of steel members, with light chains stretched between them. The chains can be readily lowered to allow vehicles to pass, but if a vehicle hits the chain when taut, the two tripods are dragged into the sides of the vehicle making further progress difficult. Since all the bits can be carried in a Land Rover, they make it easy to establish a vehicle checkpoint quickly, effectively and safely. They reduce the risk of accidentally shooting joy riders or revellers.