Has anyone had a similar experience to the following situation? We have a signing arrangement with two signs co-located on a single 219mm Jerol post. The signs are 1748mm wide by 2360mm high and 1778mm wide by 561mm high, mounted 1500mm to underside.
The signs are located on a very exposed section of carriageway and have now rotated twice in the wind. It has been suggested that grub screws could be used through the clips into the post, but there are concerns that this would affect the structural integrity of the Jerol post or the screws will snap.
As a possible solution we are considering installing a single 76mm post offset 750mm from the existing Jerol post. The idea is that the post will not provide any structural stability but purely prevent the sign from rotating. It would great to understand if anyone has come across a similar issue or if anyone understands the implications on the passive safety of the arrangement.
For background our authorities current position statement is that we comply with the requirement of TA89/05
I suggest initially talking to Mallatite (suppliers of Jerol posts) about the problem. My feeling is that a small hole drilled into the post to accommodate a grub screw is unlikely to affect it structurally, but they would be the best people to ask as they have probably come across this problem before.
A secondary post sounds an expensive solution and, as you say, being an untested arrangement it is uncertain how it would perform in a crash.
I presume you’re aware that TA 89/05 was withdrawn by HA in 2008, and Highways England now just use the UK National Annex to EN 12767 as their guidance. But there is of course nothing to stop a local authority still using it as their standard.