US Patent 7497640 Road safety barriers

A road safety barrier having four or more ropes 4-7 supported by posts 1-3 rigidly mounted on or in the ground is described. Each rope is held in tension against the posts and follows a sinuous path between the posts. The ropes are tensioned against the posts and this gives rise to a combined frictional resistance to displacement of the ropes relative to each post along the length of the safety barrier. The structure of at least some of the posts and/or their mounting with respect to the ground defines a minimum bending yield strength in a direction along the length of the barrier. This minimum bending yield strength is greater than the bending moment resulting from the combined frictional resistance forces acting on the post.