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Infamous 'can opener' bridge in Durham, NC, is finally being 'fixed'... 4

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JohnRBaker

JohnRBaker

Mechanical
Jun 1, 2006
35,444
This particular bridge has been the subject of many posts in this forum over the years. Well, it appears that they're finally going to do something that they hope will resolve the problem. Note that they are only raising the bridge eight inches, increasing the clearance from 11'-8" to 12'-4". Not sure how much this will help, but it's the best they can do without completely replacing the bridge and re-engineering the rail route.

North Carolina’s Infamous ‘Can Opener’ Bridge May Decapitate Trucks No Longer

An 11-foot-8-inch railroad overpass in Durham is being raised after years of viral videos showing it lopping the tops off of vehicles.


John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without
 
Are they raising the bridge or lowering the roadway below? With only two weeks for construction I have to believe it's the latter.
 
azcats said:
Are they raising the bridge or lowering the roadway below? With only two weeks for construction I have to believe it's the latter.
Click to expand...

According to this Atlas Obscura article, there's a sewer right below the roadway. My bet is that they're lifting the existing span and raising the abutments slightly, then re-grading the tracks on either side. But, we'll know for sure soon enough.
 
That's probably the limit on how much the tracks can be raised without completely redoing the entire overpass to make sure the trains don't hang air going at their maximum allowable speeds.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
 
Not affecting the grade crossings on each side of this location is probably the highest priority followed by limiting the maximum incline on each side of the bridge.

I hope the only reason for this is pedestrian safety as it is otherwise a national treasure in the art of paying attention while driving.
 
8 measly inches.. I hope it helps. Those air conditioner sweeps will probably still happen. LOL

Keith Cress
kcress -
 
My guess, based just on what's written above, is that the bridge will be replaced with one that has less depth but the track grade won't be altered. New abutments could have already been placed using jump spans on either side of the main span to allow the abutment excavation and construction. Perhaps poured weeks ago and now fully cured.
 
Sidney Australia got tired of repairing tunnels, so they installed these difficult to overlook stop signs projected onto a cascading sheet of water, all triggered by overheight vehicles.

article-2325904-19D2AAC2000005DC-733_308x185.jpg
 
The interior of the tunnel is always relatively dark, making an ideal backdrop. There is also a manned station near to that water curtain which is where the monitor those photos were taken is. Unlike the tunnel, the underpass has nearby alternates so when it is blocked there are options, making an expensive 24 hour manned warning overkill for the situation.
 
One of my office mates lives in Durham. He is very familiar with the “can opener” and the years of entertainment the truck drivers have delivered.

Good Luck,
Latexman
 
"...expensive 24 hour manned warning..."

You've incorrectly associated two somewhat-related facts, linking them incorrectly.

Tunnels have staff to monitor traffic anyway, no matter if they have a Water Curtain or not. Especially if oversized trucks are constantly crashing into their tunnels. The staff would have to be stationed near the tunnel entrances for obvious reasons.

The triggering of the Water Curtain itself is obviously fully automatic; clearly it has to be. As a stand alone warning, it need not necessarily be 'expensively manned' as you've implied. Even if it needs to be reset manually, that's a ten-minute job, not 7 hours extracting the 3rd wedged lorry of the morning.

The Sydney tunnel will need significantly fewer staff overall if they're not spending their days extracting oversize trucks wedged into tunnels by inattentive bogans. The Water Curtain has presumably led to a dozen tunnel staffers being made redundant.

If one of the few remaining Sydney tunnel staffers happens to wander over after the system has been triggered, it would be to scold the driver, take away their Crown Lager, and assist them in backing up in heavy Sydney traffic.

And finally, if an underpass is overly bright, then the Water Curtain water could be tinted black to enhance contrast.

...Or they can lower the road by eight inches.

 
The only thing that makes the water curtain possible is 24 hour watching to see that it functions. The fact that there is a monitor nearby was the first and most basic requirement, no matter the other duties. If the water supply fails or the lamp fails then someone has to fix that. It cannot go months without a look. The bridge gets about 1 truck a month; only about 1 per year required extraction. So the bridge would move from zero people to at least 3 full time on duty.

The water curtain being tinted black would absorb the light projected on it. Just water will not stop drivers any more than the majority that run the red light who strike the bridge.
 
"The only thing that makes the water curtain possible is 24 hour watching to see that it functions. ...If the....lamp fails...

Yes of course, just like traffic signal lights. Every signalized intersection needs at least three full time staff.

[ponder]

 
But this is a railway bridge no?

They really don't like being run into as they usually need to check the tracks each time to make sure there isn't a risk of de-railment and stop trains until it's done. At least that's what happens in the UK....

A water curtain idea sounds like a proportionate response to me.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
Littleinch
This bridge has an armored Beam in front of the bridge on a separate structure to do the can opening

Hydrae
 
Makes it better. I hope they raise this as part of the work! Wonder what margin they allow on the bridge vs barriver.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
That particular overpass even has its own website The barrier is pretty beefy, but debris can still be seen hitting the trestle and shaking it. The site claims there's been at least 147 collisions at this overpass. The last was in June of this year.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
 
I watched several of those bridge videos (from the links above) and it's amazing how many people run the red-light at the intersection next to the bridge, including many of the trucks that crash into the barrier. It's like the stop-light is merely a suggestion.

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without
 
There's one video where the rental truck makes the turn away from the overpass, but, for some reason, decides to try it anyway, and comes back, and since there's a video...

You would think ANY rental truck company in the area would WARN renters to stay away from that bridge; but maybe that's a way to total the truck and get insurance money to buy a new one. I recall a couple of videos I watched a few years ago where the barrier cleanly zippered the tops of some trucks, but I guess that's the luck of draw and how much the truck was loaded down.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
 
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