Abstract: An energy absorbing system having a stanchion, a linearly extendable energy absorber coupled to the stanchion, a net coupled to the energy absorber, wherein the net transfers force to the energy absorber, and a securing mechanism that maintains tension between the net and the energy absorber until acted upon by tensile forces of at least a minimum threshold force, wherein at least a portion of the system is retractable into the ground.

Abstract: An energy absorbing system having a stanchion, a linearly extendable energy absorber coupled to the stanchion, a net coupled to the energy absorber, wherein the net transfers force to the energy absorber, and a securing mechanism that maintains tension between the net and the energy absorber until acted upon by tensile forces of at least a minimum threshold force, wherein at least a portion of the system is retractable into the ground.

Abstract: A heavy duty ground retractable automobile barrier for a railroad crossing. Concrete bunkers are placed at each side of a roadway. An upstanding concrete-filled steel pipe fixed in each bunker has a sleeve for rotational and axial movement. Shock absorbers are mounted on each sleeve. A net extends across the road and is attached to the opposite ends of the shock absorbers. Collision of an automobile with the net creates tensile forces in the net. The shock absorbers expand while rotating about the pipe's axis in response to tensile forces from the net that meet or exceed a minimum threshold. Forces from the net pass through the axis of the steel pipe. The net is stored in a pit transverse the roadway parallel to the railroad tracks and is raised and lowered as appropriate. The net includes a cable that extends across the road in a wave pattern, having peaks, valleys and midpoints, wherein tangents of the wave midpoints are at least 90 degrees from tangents of the peaks and valleys.

Abstract: A heavy duty ground retractable automobile barrier for a railroad crossing. Concrete bunkers are placed at each side of a roadway. An upstanding concrete-filled steel pipe fixed in each bunker has a sleeve for rotational and axial movement. Shock absorbers are mounted on each sleeve. A net extends across the road and is attached to the opposite ends of the shock absorbers. Collision of an automobile with the net creates tensile forces in the net. The shock absorbers expand while rotating about the pipe's axis in response to tensile forces from the net that meet or exceed a minimum threshold. Forces from the net pass through the axis of the steel pipe. The net is stored in a pit transverse the roadway parallel to the railroad tracks and is raised and lowered as appropriate. The net includes a cable that extends across the road in a wave pattern, having peaks, valleys and midpoints, wherein tangents of the wave midpoints are at least 90 degrees from tangents of the peaks and valleys.

Abstract: A heavy duty ground retractable automobile barrier for a railroad crossing. Concrete bunkers are placed at each side of a roadway. An upstanding concrete-filled steel pipe fixed in each bunker has a sleeve for rotational and axial movement. Shock absorbers are mounted on each sleeve. A net extends across the road and is attached to the opposite ends of the shock absorbers. Collision of an automobile with the net creates tensile forces in the net. The shock absorbers expand while rotating about the pipe's axis in response to tensile forces from the net that meet or exceed a minimum threshold. Forces from the net pass through the axis of the steel pipe. The net is stored in a pit transverse the roadway parallel to the railroad tracks and is raised and lowered as appropriate. The net includes a cable that extends across the road in a wave pattern, having peaks, valleys and midpoints, wherein tangents of the wave midpoints are at least 90 degrees from tangents of the peaks and valleys.

Abstract: A heavy duty ground retractable automobile barrier for a railroad crossing. Concrete bunkers are placed at each side of a roadway. An upstanding concrete-filled steel pipe fixed in each bunker has a sleeve for rotational and axial movement. Shock absorbers are mounted on each sleeve. A net extends across the road and is attached to the opposite ends of the shock absorbers. Collision of an automobile with the net creates tensile forces in the net. The shock absorbers expand while rotating about the pipe's axis in response to tensile forces from the net that meet or exceed a minimum threshold. Forces from the net pass through the axis of the steel pipe. The net is stored in a pit transverse the roadway parallel to the railroad tracks and is raised and lowered as appropriate. The net includes a cable that extends across the road in a wave pattern, having peaks, valleys and midpoints, wherein tangents of the wave midpoints are at least 90 degrees from tangents of the peaks and valleys.

Abstract: A heavy duty ground retractable automobile barrier for a railroad crossing. Concrete bunkers are placed at each side of a roadway. An upstanding concrete-filled steel pipe fixed in each bunker has a sleeve for rotational and axial movement. Shock absorbers are mounted on each sleeve. A net extends across the road and is attached to the opposite ends of the shock absorbers. Collision of an automobile with the net creates tensile forces in the net. The shock absorbers expand while rotating about the pipe's axis in response to tensile forces from the net that meet or exceed a minimum threshold. Forces from the net pass through the axis of the steel pipe. The net is stored in a pit transverse the roadway parallel to the railroad tracks and is raised and lowered as appropriate. The net includes a cable that extends across the road in a wave pattern, having peaks, valleys and midpoints, wherein tangents of the wave midpoints are at least 90 degrees from tangents of the peaks and valleys.

Abstract: A heavy duty ground retractable automobile barrier for a railroad crossing. Concrete bunkers are placed at each side of a roadway. An upstanding concrete-filled steel pipe fixed in each bunker has a sleeve for rotational and axial movement. Shock absorbers are mounted on each sleeve. A net extends across the road and is attached to the opposite ends of the shock absorbers. Collision of an automobile with the net creates tensile forces in the net. The shock absorbers expand while rotating about the pipe's axis in response to tensile forces from the net that meet or exceed a minimum threshold. Forces from the net pass through the axis of the steel pipe. The net is stored in a pit transverse the roadway parallel to the railroad tracks and is raised and lowered as appropriate. The net includes a cable that extends across the road in a wave pattern, having peaks, valleys and midpoints, wherein tangents of the wave midpoints are at least 90 degrees from tangents of the peaks and valleys.

Abstract: A heavy duty shock absorber system for resisting large forces as may be encountered, for example, in a restraining barrier for a railroad crossing. A concrete bunker with an upstanding concrete-filled steel pipe has a hydraulic, compressive shock absorber mounted on the steel pipe for rotational, axial, and orthogonal movement. Forces applied to the shock absorber always pass through the axis of the steel pipe, thereby maximizing the resistance to the force while minimizing the necessary size of the system. A net is stored in a pit transverse the roadway parallel to the railroad tracks and is raised and lowered as appropriate. Each end of the net is attached to shock absorbing systems of the type described above.