Breakaway guardrail post for a highway crash attenuation system
A highway crash attenuation system having an improved breakaway guardrail post. An improved upper section of Post 1 has an anchor bearing plate with a cooperating stabilizing bolt engaging with the upstream face of the upper post section. The downstream side of the upper post section is provided with split, spaced-apart strut sections which do not obstruct the rear cable pass through notch.
1. A highway crash attenuation system having an improved breakaway guardrail post said post comprising:
an upper post section and a lower post section, said upper post section having a first anchor cable through notch in an upstream wall of said upper post section and a second anchor cable through notch in a downstream wall of said upper post section, and an anchor cable passing through said first notch in said upstream wall and said second notch in said downstream wall;
spaced-apart sections of lateral support lips extending along a lower edge of a downstream face of said upper post section, said spaced-apart support lip sections having a space therebetween such that a cable passes through opening in said second notch is unobstructed;
a cable anchor bearing plate engaged with an upstream face of said upper post section, said bearing plate having a first anchor cable through hole through which an anchor cable is adapted to pass and be retained therein by a locking nut affixed to an upstream most end of said anchor cable, wherein said bearing plate is disposed at a predetermined angle with respect to said first breakaway post by engaging a spacer between a top end of said plate and an upstream face of said upper post; and
an anchor bearing stabilizing bolt extending through a second hole in said bearing plate and secured in a stabilizing hole in said upstream face of said upper post section.
2. The highway crash attenuation system of claim 1 , wherein said spacer is a section of angle iron joined with said upstream face of said upper section of said post.
3. The highway crash attenuation system of claim 1 , further comprising: a ledge on top of said lower section of said post, said ledge extending under said cable anchor bearing plate to provide a shelf for supporting said bearing plate and preventing rotation of said cable anchor bearing plate.
4. The highway crash attenuation system of claim 3 , wherein said upstream-most end of said anchor cable remains retained by said cable anchor bearing plate after vehicular impact separating said upper post section from said lower post section.