GB1356936A - Crash barriers - Google Patents

Abstract

1356936 Highway crash barriers C C PHILLIPS 27 Aug 1971 [26 Aug 1970] 41068/70 Heading E1G A roadway W is provided along one side with twin laterally-spaced crash barriers 1, 3 each comprising a rail, cable or fence 2, 4 which is preferably discontinuous in length and which is supported on a respective row of posts 5, 7, the posts and/or rail being so constructed or mounted that each barrier of a pair has less resistance to impact on its outer side than on its inner side whereby (if the barrier spacing is wide enough( an impacting vehicle V is trapped between the two barriers. The twin barrier is shown on the central reservation R of a dual carriageway E-W. Various embodiments of uni-directionally yieldable posts and rails are described. Fig. 2 shows a post pivoted at 11 to the edge of a concrete road W and yieldably held by a bolted-on slotted strap 13 so that it has greatest resistance to impact from the direction A. The strap 13 may be replaced by alternative securing means. In modifications (a) the post is notched from one side (Fig. 6, not shown); (b) the post is supported on one side by concrete and on the other by gravel &c, and has its lower end held by a concrete stirrup (Fig. 4, not shown) or by a strap (Fig. 5, not shown) which allows pivotal movement into the gravel etc; (c) the barrier rails (2, 4, Fig. 3, not shown) are shear-bolted at (18) to the inner sides of the posts (5a, 7a), an auxiliary traffic-facing rail (20) being provided on the outer sides of the posts. Each barrier is preferably arranged to collapse in sections, and may comprise end-to-end rail members each supported respectively on two posts to provide side-by-side post pairs which may be releasably coupled as illustrated in Figs. 7, 8 or 9 (not shown) by means which yield in one direction but not the other.