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11 Foot 8 – The Can-opener Bridge

11foot8.com

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Re: 11 Foot 8 – The Can-opener Bridge

#191

Post by iggldiggl »

sebastien_bois wrote: post #3

Still not high enough. They raised it another 8 inches to make it an even 12ft not too long ago, but evidently that still not enough. One would think they would've looked more closely at the traffic on that road and adjusted it accordingly. It's also really silly to have a sign indicating that too large vehicles must turn, which most drivers won't read/see in time, and practically force them to crash into the bridge,…

> One would think they would've looked more closely at the traffic on that road and adjusted it accordingly.

They didn't raise it only eight inches because they simply felt like it and picked a number out of their hat - eight inches was the most they could do without also impacting a nearby level crossing. Ballasting plain track up to a higher level can be done relatively easily (up to a certain extent of course), whereas touching the level crossing requires more work and also creates problems with the road geometry there:

If you raise the track across the level crossing too much, you create a nice little hump on which long vehicles can now get stuck, which isn't what you'd want, either. Fixing that in turn means rebuilding an even more considerable section of the crossing street, with all that that entails...

Re: 11 Foot 8 – The Can-opener Bridge

#192

Post by jcranmer »

Svip wrote: post #153

The maximum standard height for a vehicle is 4 metres in Europe. All E-routes in Europe require that bridges and tunnels can clear at least 4 metres, otherwise they cannot get designated with the E-route. Is there a similar concept of safe routes for lorries and buses in the US?

The US has a standard clearance of 14' (or 16' for interstate highways); anything lower than that would have low clearance signs of various sorts. These values are comfortably above 4m.

The roads that have these low clearances are usually local roads whose right-of-way was constrained a hundred years ago, or "parkways" originally devised to permit motorists to enjoy scenic drives and unencumbered by heavy truck traffic (possibly also built 100 years ago!).

Re: 11 Foot 8 – The Can-opener Bridge

#194

Post by throwaway2048 »

rusk wrote: post #169
tetris11 wrote: post #164

Earlier quoted context omitted.

They're not stupid, they're tired. They've been driving day in day out on autopilot. Signs begin to blur after a while.

Probably shouldn’t be driving so ...

There is a long list of unhelpful "Probably" statement's that don't solve the problem.

Re: 11 Foot 8 – The Can-opener Bridge

#195

Post by Aeolun »

ptr wrote: post #173
cam_l wrote: post #114

Earlier quoted context omitted.

I never understood the high-tech approach to this problem. Where i am from they have large metal tubes dangling down a ways in front of the bridge. Makes it sound like you have already hit it. Another more insistent approach I have seen elsewhere is to mount a large steel bar across the road, which takes the top of the truck off before they hit the bridge. (edit:not very simple problem, obviously..)

The gas tank on top of a bus in Stockholm exploded when the bus was about to enter a tunnel protected by a metal bar: https://youtu.be/4pVStENP_Y4

I mean, that sucks, but the same thing would have happened if it had entered the tunnel?

Only possibly worse, as I assume the explosion would have nowhere to go but down.

Re: 11 Foot 8 – The Can-opener Bridge

#196

Post by Theodores »

GiorgioG wrote: post #46
jacquesm wrote: post #43

You have to wonder how much it would cost to dig that out two feet and solve the problem. Likely a lot less than the annual capital destruction.

There's a sewer main near the bridge so, very expensive.

The sewer and the railway are immovable objects, hence the problem.

The rental truck depot up the road contribute to the problem. In theory this could be relocated but this has to have a cost greater than the loss of a few rental truck tops.

There is a road junction next to the bridge meaning the parallel road limits the options for slowing down tall vehicles before the bridge.

Thus far in this comment thread your comment has been the only one that sheds some light on the situation.

Re: 11 Foot 8 – The Can-opener Bridge

#197

Post by jansan »

ddingus wrote: post #143
Animats wrote: post #53

The Sidney Harbor Tunnel had a similar problem. They came up with an elaborate but successful solution.[1] There are detectors and huge flashing warning signs that light up. Then, there's the last-chance sign. At the entrance to the tunnel, pumps force a curtain of water straight down across the entire roadway. Then a powerful laser system projects a giant octagonal red STOP sign onto the water curtain, filling the e…

That water display is excellent! Great engineering on what appears to be a tough problem.

And what makes it even better is that it's a truly geeky solution. You would expect something like this in the homes of geek super villains like Vector (from Despicable Me) or Bill Gates (yes, I am joking here)

Re: 11 Foot 8 – The Can-opener Bridge

#198

Post by zentiggr »

ptr wrote: post #173
cam_l wrote: post #114

Earlier quoted context omitted.

I never understood the high-tech approach to this problem. Where i am from they have large metal tubes dangling down a ways in front of the bridge. Makes it sound like you have already hit it. Another more insistent approach I have seen elsewhere is to mount a large steel bar across the road, which takes the top of the truck off before they hit the bridge. (edit:not very simple problem, obviously..)

The gas tank on top of a bus in Stockholm exploded when the bus was about to enter a tunnel protected by a metal bar: https://youtu.be/4pVStENP_Y4

So the bar did the job of ablative armor, per se.

Still not remotely optimal but avoiding damage to the tunnel requiring far more blockage seems like a good tradeoff.

Re: 11 Foot 8 – The Can-opener Bridge

#199

Post by JeremyNT »

jacquesm wrote: post #43

You have to wonder how much it would cost to dig that out two feet and solve the problem. Likely a lot less than the annual capital destruction.

They actually raised the bridge a year or so ago, putting it almost a foot taller. There are way fewer collisions now.

Re: 11 Foot 8 – The Can-opener Bridge

#200

Post by SOLAR_FIELDS »

mauvehaus wrote: post #2

Boston is home to any number of bridges that trucks don't fit under, most famously on Storrow Drive. Rating truck/bridge interactions has become a bit of a past time on universalhub: https://www.universalhub.com/storrow Every year when college students move back in and out, the powers that be put up illuminated construction signs everywhere to try to keep the number of rental trucks on roads they shouldn't be to a mi…

I drove a box truck (most often Penske/Ryder rentals just like the ones you see in this video) around most of the nation for a job when I was younger. The only two cities I had real trouble with clearances were Boston and Chicago. New York City was also a pain but for different and obvious reasons.

I suspect if it hasn’t happened yet a decent commercial software solution would be to produce an app that took OSM and overlay all of the bridges with clearances in major cities into it so that you could route around them after entering your height. I specifically remember doing a lot of reversing back up streets in Chicago because nothing like that existed at the time (this was in the early 2010s).

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