ENERGY ABSORBING SYSTEM

摘要

A heavy duty ground retractable automobile barrier for a railroad crossing (12). Concrete bunkers (30) are placed at each side of a roadway (10). An upstanding concrete-fill steel pipe (32) fixed in each bunker (30) has a sleeve (72) for rotational and axial movement. Shock absorbers (84) are mounted on each sleeve (72). A net (20) extends across the road (10) and is attached to the opposite ends of the shock asorbers (84). Collision of an automobile (26) with the net (20) creates tensile forces in the net (20). Th e shock absorbers (84) expand while rotating about the pipe's axis in response to tensile forces from the net (20) that meet or exceed a minimum threshold. Forces from the net (20) pass through the axis of the steel pipe. The net (2 0) is stored in a pit (38) transverse the roadway (10) parallel to the railroad tracks (12) and is raised and lowered as appropriate. The net (20) includes a cable tha textends across the road in a a wave pattern, having peaks, valley s and midpoints.