91–100 of 206 posts
The footage of the 20 ton beam getting knocked out of the tunnel ceiling by a truck was remarkable. I hope there were no injuries!
I'm surprised a truck was able to knock it down. A 20 ton beam sounds like something that's rather important, I figured it would be attached fairly securely.
That's a cute high-tech solution. A simpler one is to put a horizontal bar, the same height as the tunnel's ceiling, which will physically stop the truck before causing millions worth of damages. It's often done in France, sometimes with an early warning: a first arch with chains hanging to the maximal height. It makes a lot of noise on the truck's top, but won't destroy it.
That's a cute high-tech solution. A simpler one is to put a horizontal bar, the same height as the tunnel's ceiling, which will physically stop the truck before causing millions worth of damages. It's often done in France, sometimes with an early warning: a first arch with chains hanging to the maximal height. It makes a lot of noise on the truck's top, but won't destroy it.
Did you see the truck in the video take out an enormous steel beam that was presumably attached to the structure of the tunnel in some kind of permanent way? How would your solution avoid the same fate?
I'd try a 3-stage contact-warning system:
(1) hanging bar that makes noise on contact but causes little damage. This might even go before a suitable turn-off.
(2) breakaway cord with trailing noisemakers. This would be torn from its mast by the collision, and drag noisy items behind, emphasizing the need to stop and investigate.
(3) hard bar providing some slowing/resistance (but almost certainly not full stopping power, given the position and expense). By design this would actually damage the vehicle (and even risk harming the driver), approaching the same level of damage that would occur at functional tunnel-entry. But, it'd happen earlier where easier to clear/repair.
And I think some people will STILL crash on the tunnel anyway. I made a arcade game once: www.abril.com.br/blog/campus-party/2011/01/19/fanatico-por-jogos-leva-seu-proprio-fliperama-para-a-arena/ It has instructions printed on the sides of the screen... It was VERY, VERY, VERY common to someone ask people around them what a button do (sometimes to even random passerby people, or for example a couple arrived at the ma…
its because most instructions are unhelpful and a waste time to read, so we're conditioned to ignore them.
That's a cute high-tech solution. A simpler one is to put a horizontal bar, the same height as the tunnel's ceiling, which will physically stop the truck before causing millions worth of damages. It's often done in France, sometimes with an early warning: a first arch with chains hanging to the maximal height. It makes a lot of noise on the truck's top, but won't destroy it.
low-tech solution: http://vanishingpoint.at/wordpress/wp-content/uploads/2010/1... (edit: actual image url instead of article)
More severe low-tech solution: https://maps.google.co.uk/maps?q=blackwall+tunnel&hl=en&... (Blackwall Tunnel, northbound, London) And again, just in case you missed the scraping sounds the first time: https://maps.google.co.uk/maps?q=blackwall+tunnel&hl=en&... (For some reason they don't appear to have anything similar going south...)
That's a cute high-tech solution. A simpler one is to put a horizontal bar, the same height as the tunnel's ceiling, which will physically stop the truck before causing millions worth of damages. It's often done in France, sometimes with an early warning: a first arch with chains hanging to the maximal height. It makes a lot of noise on the truck's top, but won't destroy it.
These will make a fair mess of a vehicle, I saw them hitting a lorry once but are pretty attention grabbing.
The Blackwall Tunnel has different heights and widths for different lanes due to the tunnel profile which is why the restrictions are different in each lane in this photo.