6 ms·

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

by fab13n 13y ago

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.

Osmium 13y ago
A similar solution is used in my area yet perplexingly it still doesn't seem to stop it happening... so I think new ideas like this are definitely a good thing.
evan_ 13y ago
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?
- gojomo 13y ago
  The warning beam is several stopping-distances before the tunnel itself, and far easier to replace/reconstruct. 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.
  - numbsafari 13y ago
    And yet, with this solution, no repair is needed for either the truck or the infrastructure. The vehicle is able to be removed under its own power, the driver is not injured, there is no debris. If you are in a vehicle behind a truck that has damage to its top, you very likely will have damage to your vehicle from flying debris.
    - joezydeco 13y ago
      Or a ten-ton beam falling on your car.
    - gojomo 13y ago
      Oh, I like the water-wall too. But a driver who misses the 1st two no-damage physical-contact warnings I've proposed -- and thus would hit the damaging third hard bar -- would quite possibly ignore the water-wall too. After all, the water wall seems primarily visual, and the driver has already missed numerous visual warnings. The contact protectors add collision-noise and vibration, which are rare enough that even a dozing/road-hypnotized driver is likely to take note. Comparative testing is of course justified.
- gambiting 13y ago
  Solid beam is probably a bad idea, but many tunnels have chains dangling above the road at the tunnel's maximum height - if you hit them, you will hear it,but they will do little damage to the vehicle.
  - masklinn 13y ago
    Solid beam is an excellent idea as last recourse, from a structural POV since the vehicle is going to be destroyed anyway it's better to destroy it before it damages the tunnel itself.
- twistedpair 13y ago
  That beam they took out is called a "sacrificial beam." It was not a structural support, but was meant to take the impact before any structural members were damaged. You'll see them on many modern bridges and underpasses.
  - wizzard 13y ago
    That's interesting and seems like a good idea, except perhaps it should be paramount that the 20-ton beam NOT fall on the following cars! That is an entirely different meaning of "sacrificial"...
    - twistedpair 13y ago
      See the videos on 11foot8.com, that beam is a freestanding structure separate from the bridge solely designed to decapitate trucks.
  - JshWright 13y ago
    The sacrificial beam that appeared to fall on top of the car behind the truck?
- Freestyler_3 13y ago
  Something that causes the vehicles engine to stop... a shock? It wouldn't stop the vehicle but it will decrease destructive force. Or a trapdoor (warning this is a joke disregard it if you know you don't like jokes)
  - bigiain 13y ago
    (intentionally ignoring joke warning…) Excellent plan! A trapdoor! In the harbour tunnel! Relevant anecdote: My Dad worked for the company who built the fire control system in the Sydney Harbour Tunnel. It's got (from fuzzy memory - numbers not guaranteed accurate) 128 sectors of "deluge valves". It's got pumps capable of keeping up with only 10 of those sectors of deluge valves - more than 10 sectors of valves open means even with all pumps running at maximum capacity the tunnel will fill up with water. There's some software controlling it all which is intended to ensure the operators don't accidentally flood the tunnel. Dad knows who wrote that software - he won't drive through the tunnel.
    - Freestyler_3 13y ago
      Yes, I hope though that the pressure on the writer of that software was enough to make him check thoroughly for errors.
acqq 13y ago
I guess they are afraid that the broken bar can damage some other vehicle. Still, something heavier that can be damaged and can stop the truck before the tunnel is the proper solution, not the strange projections. Drivers are too sleepy sometimes, in spite of the expectations of the idealists.
fr0sty 13y ago
One additional benefit to the water sign: It doesn't leave the roadway strewn with debris.
YellowRex 13y ago
A train company did this in North Carolina instead of raising the height of their trestle: http://11foot8.com/ http://11foot8.com/
exit 13y ago
self-driving car systems are going to eliminate human operators in a few years anyway, no?
- ars 13y ago
  In a few decades maybe, certainly not a few years.
webmonkeyuk 13y ago
The Blackwall Tunnel in London has a something similar with heavy metal weights on chains. http://www.sabre-roads.org.uk/forum/viewtopic.php?f=1&t=6447 http://www.sabre-roads.org.uk/forum/viewtopic.php?f=1&t=... 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.
ghjm 13y ago
In some jurisdictions, the owner of the truck can sue you for damages if the structure was constructed with the intent and purpose of damaging the truck.
- FireBeyond 13y ago
  Sad, when the alternative is no device there, and the owner of the tunnel/bridge can sue the truck owner for damages.
twistedpair 13y ago
You just need to remember that a small number of people are just not going to get it. Mostly truck drivers that are dead tired. That water screen does the trick because you're not expecting it. Signs, bumps, and noises are all common to highway driving. In Boston a few months ago a coach bus had the top ripped off going under a 10ft bridge on a road that truck/bus traffic is banned from. The driver hit several low bars and signs and plowed onward until the bridge cut the top off. Several times a year this happens on Storrow Drive, despite all the warning devices as some drivers just can't be reached. http://bostonherald.com/news_opinion/local_coverage/2013/02/dozens_hurt_after_tour_bus_crashes_boston_bridge http://bostonherald.com/news_opinion/local_coverage/2013/02/...
- brianbreslin 13y ago
  we had a fatal bus crash at the Miami airport back in december due to the driver not heeding the signs . http://www.miamiherald.com/2012/12/04/3126826/details-emerge-about-deadly-miami.html http://www.miamiherald.com/2012/12/04/3126826/details-emerge...
  - glanch 13y ago
    "When Miami-Dade Fire Rescue arrived five minutes and 10 seconds after the first emergency call, they began to pull passengers out of the window. Lopez, now out of gauze, told rescue workers that the victims were all Jehovah’s Witnesses, and couldn’t receive blood transfusions because of their faith." Sigh.
- LaGrange 13y ago
  "Mostly truck drivers that are dead tired." This. People don't even realize how important it is that people operating heavy machinery are well rested, and sometimes even put down appropriate regulations as just "worker's issues". Then you get a sleepy, bored guy on a highway, with neither awareness to spot dangerous situations, or willpower left to restrain from doing stupid things. It's a testament to how good they are at their jobs that they get to their destinations at all.
  - 13y ago
otoburb 13y ago
They showed footage where low bars did physically stop the truck (or at least tore off the top part of the cargo container), but this still caused debris to be showered across the tunnel entrance, which resulted in large traffic delays.
Devilboy 13y ago
That causes stuff to be knocked off the top of the truck onto other cars on the road possibly killing innocent people.
noisysocks 13y ago
Yes, but that would require that the road close for debris to be picked up. The water wall solution allows the tunnel to resume operation quickly. A small jam in the Sydney Harbour Tunnel blocks the whole city, so we want to avoid unnecessarily large delays.

by fab13n 13y ago

Osmium 13y ago

A similar solution is used in my area yet perplexingly it still doesn't seem to stop it happening... so I think new ideas like this are definitely a good thing.

evan_ 13y ago

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?

gojomo 13y ago
The warning beam is several stopping-distances before the tunnel itself, and far easier to replace/reconstruct. 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.
- numbsafari 13y ago
  And yet, with this solution, no repair is needed for either the truck or the infrastructure. The vehicle is able to be removed under its own power, the driver is not injured, there is no debris. If you are in a vehicle behind a truck that has damage to its top, you very likely will have damage to your vehicle from flying debris.
  - joezydeco 13y ago
    Or a ten-ton beam falling on your car.
  - gojomo 13y ago
    Oh, I like the water-wall too. But a driver who misses the 1st two no-damage physical-contact warnings I've proposed -- and thus would hit the damaging third hard bar -- would quite possibly ignore the water-wall too. After all, the water wall seems primarily visual, and the driver has already missed numerous visual warnings. The contact protectors add collision-noise and vibration, which are rare enough that even a dozing/road-hypnotized driver is likely to take note. Comparative testing is of course justified.
gambiting 13y ago
Solid beam is probably a bad idea, but many tunnels have chains dangling above the road at the tunnel's maximum height - if you hit them, you will hear it,but they will do little damage to the vehicle.
- masklinn 13y ago
  Solid beam is an excellent idea as last recourse, from a structural POV since the vehicle is going to be destroyed anyway it's better to destroy it before it damages the tunnel itself.
twistedpair 13y ago
That beam they took out is called a "sacrificial beam." It was not a structural support, but was meant to take the impact before any structural members were damaged. You'll see them on many modern bridges and underpasses.
- wizzard 13y ago
  That's interesting and seems like a good idea, except perhaps it should be paramount that the 20-ton beam NOT fall on the following cars! That is an entirely different meaning of "sacrificial"...
  - twistedpair 13y ago
    See the videos on 11foot8.com, that beam is a freestanding structure separate from the bridge solely designed to decapitate trucks.
- JshWright 13y ago
  The sacrificial beam that appeared to fall on top of the car behind the truck?
Freestyler_3 13y ago
Something that causes the vehicles engine to stop... a shock? It wouldn't stop the vehicle but it will decrease destructive force. Or a trapdoor (warning this is a joke disregard it if you know you don't like jokes)
- bigiain 13y ago
  (intentionally ignoring joke warning…) Excellent plan! A trapdoor! In the harbour tunnel! Relevant anecdote: My Dad worked for the company who built the fire control system in the Sydney Harbour Tunnel. It's got (from fuzzy memory - numbers not guaranteed accurate) 128 sectors of "deluge valves". It's got pumps capable of keeping up with only 10 of those sectors of deluge valves - more than 10 sectors of valves open means even with all pumps running at maximum capacity the tunnel will fill up with water. There's some software controlling it all which is intended to ensure the operators don't accidentally flood the tunnel. Dad knows who wrote that software - he won't drive through the tunnel.
  - Freestyler_3 13y ago
    Yes, I hope though that the pressure on the writer of that software was enough to make him check thoroughly for errors.

acqq 13y ago

I guess they are afraid that the broken bar can damage some other vehicle. Still, something heavier that can be damaged and can stop the truck before the tunnel is the proper solution, not the strange projections. Drivers are too sleepy sometimes, in spite of the expectations of the idealists.

fr0sty 13y ago

One additional benefit to the water sign: It doesn't leave the roadway strewn with debris.

YellowRex 13y ago

A train company did this in North Carolina instead of raising the height of their trestle: http://11foot8.com/ http://11foot8.com/

exit 13y ago

self-driving car systems are going to eliminate human operators in a few years anyway, no?

ars 13y ago
In a few decades maybe, certainly not a few years.

webmonkeyuk 13y ago

The Blackwall Tunnel in London has a something similar with heavy metal weights on chains. http://www.sabre-roads.org.uk/forum/viewtopic.php?f=1&t=6447 http://www.sabre-roads.org.uk/forum/viewtopic.php?f=1&t=... 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.

ghjm 13y ago

In some jurisdictions, the owner of the truck can sue you for damages if the structure was constructed with the intent and purpose of damaging the truck.

FireBeyond 13y ago
Sad, when the alternative is no device there, and the owner of the tunnel/bridge can sue the truck owner for damages.

twistedpair 13y ago

You just need to remember that a small number of people are just not going to get it. Mostly truck drivers that are dead tired. That water screen does the trick because you're not expecting it. Signs, bumps, and noises are all common to highway driving. In Boston a few months ago a coach bus had the top ripped off going under a 10ft bridge on a road that truck/bus traffic is banned from. The driver hit several low bars and signs and plowed onward until the bridge cut the top off. Several times a year this happens on Storrow Drive, despite all the warning devices as some drivers just can't be reached. http://bostonherald.com/news_opinion/local_coverage/2013/02/dozens_hurt_after_tour_bus_crashes_boston_bridge http://bostonherald.com/news_opinion/local_coverage/2013/02/...

brianbreslin 13y ago
we had a fatal bus crash at the Miami airport back in december due to the driver not heeding the signs . http://www.miamiherald.com/2012/12/04/3126826/details-emerge-about-deadly-miami.html http://www.miamiherald.com/2012/12/04/3126826/details-emerge...
- glanch 13y ago
  "When Miami-Dade Fire Rescue arrived five minutes and 10 seconds after the first emergency call, they began to pull passengers out of the window. Lopez, now out of gauze, told rescue workers that the victims were all Jehovah’s Witnesses, and couldn’t receive blood transfusions because of their faith." Sigh.
LaGrange 13y ago
"Mostly truck drivers that are dead tired." This. People don't even realize how important it is that people operating heavy machinery are well rested, and sometimes even put down appropriate regulations as just "worker's issues". Then you get a sleepy, bored guy on a highway, with neither awareness to spot dangerous situations, or willpower left to restrain from doing stupid things. It's a testament to how good they are at their jobs that they get to their destinations at all.
- 13y ago

otoburb 13y ago

They showed footage where low bars did physically stop the truck (or at least tore off the top part of the cargo container), but this still caused debris to be showered across the tunnel entrance, which resulted in large traffic delays.

Devilboy 13y ago

That causes stuff to be knocked off the top of the truck onto other cars on the road possibly killing innocent people.

noisysocks 13y ago

Yes, but that would require that the road close for debris to be picked up. The water wall solution allows the tunnel to resume operation quickly. A small jam in the Sydney Harbour Tunnel blocks the whole city, so we want to avoid unnecessarily large delays.