27-10-2018, 11:01 AM
(26-10-2018, 10:43 PM)boater sam Wrote: Happens almost weekly at our canal bridge despite 6 signs starting a mile away either side ...
A mile away - is that all? The first sign that I know of warning of the 13' 0" restriction at the northbound Blackwall Tunnel is on the vehicle exit from the Eastern Docks at Dover!
There are, of course, more signs as you approach London and on the tunnel approach road itself there are signs at fairly short intervals. Height detectors at the point of no return trip illuminated OVER-HEIGHT VEHICLE DIVERT signs with an arrow pointing to the exit, but even that wasn't enough so, a few years ago, a steeply inclined escape ramp was built on the left immediately before the tunnel entrance. An overheight vehicle automatically turn traffic lights to red, stopping all traffic while PA speakers in the walls of the approach allow the police to order the driver of the vehicle to take the exit ramp and await his fate at the top. This arrangement has virtually eliminated the lengthy delays that used to occur whilst vehicles were reversed back up to surface level.
As for chains, at Blackwall they support pipes, which are much more effective! In fact, I notice here that since the last time I went this way that all the pipes are now bonded together, so hit one and you get the full force of all of them!
You will also notice that there is a 9' 0" restriction in the outside lane ...
Before these pipes were beefed up, there used to be some more pipes further on and I remember one Friday before a Bank holiday when the lights turned red just before the tunnel. There was a loud jangling noise and everything came to standstill.
A van with a high body had hit the pipes in the outside lane. The PA sprang into life, apologising for the delay caused by the driver of a vehicle in lane 2 not knowing the height of his vehicle. He would be allowed top proceed on this occasion, provided he moved his vehicle over to lane 1 and, over the weekend, he might like to ponder on how he was going to explain the damage to his rental vehicle when he returned it to its owners!
