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Fern Hollow Bridge should have been closed years before it collapsed

practical.engineering

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Re: Fern Hollow Bridge should have been closed years before it collapsed

#21

Post by _glass »

m2f2 wrote: post #8

Same stuff for the Genoa, Italy bridge (Ponte Morandi). Everyone running on that would feel vibrations and "repairs" were just lipstick on a ugly face, until it finally collapsed, with 43 dead. Surprisingly, or not so, no one was found guilty, not even the inspectors that didn't report the ongoing damages, just because "it would be too costly to rebuild it, and profits of the highway company (1) in charge of it would…

There is a really good paper with a simulation. https://gerardjoreilly.github.io/files/Journal/J6-2019_Calvi...

Re: Fern Hollow Bridge should have been closed years before it collapsed

#22

Post by p_l »

fh973 wrote: post #6

This is all interesting, but misses the point: the bridge collapsed due to a social (management, responsibilities, organization, ...) failure. Investigating the engineering story distracts from that, both in the video and apparently effectively as there is a NTSB investigation and not mentioning if any organizational review if the same rigor.

(haven't yet read the full report) If NTSB in non-aviation areas works the same way as in aviation areas, that's definitely covered by the investigation.

That's why ridiculously common case summarized as "pilot error" usually involves several components including organization, training, etc.

EDIT (After reading the report): And indeed, "what we found" section and "what we recommend" is all about how PennDOT and related orgs operate.

Re: Fern Hollow Bridge should have been closed years before it collapsed

#23

Post by panick21_ »

speakspokespok wrote: post #9

I just spent the last 4 years living in a series of countries that Americans would call ‘3rd world’. Places where proper funding of infrastructure, let alone inspections are so far below US metrics of adequate, they’d legitimately scare you. Bridges and overpasses that exist until they break and the people die. People call out to God for justice! But all that infra is then rebuilt the same way if it’s rebuilt / when…

You can also get a passport and go somewhere better. And the US is richer then those places. So take a walk and think about how to actually systematically improve infrastructure management.

Re: Fern Hollow Bridge should have been closed years before it collapsed

#24

Post by bell-cot »

MaxikCZ wrote: post #14
speakspokespok wrote: post #9

I just spent the last 4 years living in a series of countries that Americans would call ‘3rd world’. Places where proper funding of infrastructure, let alone inspections are so far below US metrics of adequate, they’d legitimately scare you. Bridges and overpasses that exist until they break and the people die. People call out to God for justice! But all that infra is then rebuilt the same way if it’s rebuilt / when…

So its okay that bridges in US fall, even when being inspected dozen of times and being urged for repairs every time, because other countries have it worse? Why not compare to country where bridges dont fall at all?

> Why not compare...

On the engineering side - you learn far more from analyzing failures than from analyzing successes.

On the social side - there's nothing mysterious about how the US bureaucracy failed here. Briefly contrasting that with Utopialand (where the society & government are different, and bridges never fall) can work as journalism. Or as a rebuttal to "failures will always happen" doomsayers. But the utility is pretty limited. The US isn't a tech company, where you might fire up the troops by talking about how your competition is delivering obviously-better results on metric X.

Re: Fern Hollow Bridge should have been closed years before it collapsed

#25

Post by keiferski »

speakspokespok wrote: post #9

I just spent the last 4 years living in a series of countries that Americans would call ‘3rd world’. Places where proper funding of infrastructure, let alone inspections are so far below US metrics of adequate, they’d legitimately scare you. Bridges and overpasses that exist until they break and the people die. People call out to God for justice! But all that infra is then rebuilt the same way if it’s rebuilt / when…

This viewpoint is funny, because if you go to many places in Eastern Europe that Americans likely consider "behind", the infrastructure is far, far superior to anything in the US. In my experience, pretty much every developed country has better infrastructure than the US.

Re: Fern Hollow Bridge should have been closed years before it collapsed

#26

Post by magicalhippo »

readthenotes1 wrote: post #4

The article goes incoherent in the first paragraph: "...collapsed without warning. ...And this bridge had been listed as being in ‘poor condition’ for over a decade. "

When it finally collapsed it did so without warning, but it was abundantly foreshadowed.

Re: Fern Hollow Bridge should have been closed years before it collapsed

#27

Post by rob74 »

dmurray wrote: post #12

If you knew all this, would you have avoided driving over the bridge? Would you have wanted the local government to close it indefinitely awaiting repairs? Let's say it would collapse with 100% certainty randomly in the next three years, and you're in the danger area for 2 minutes, with a 20% chance of fatality (in fact, nobody died). That's still around a one in 4 million chance any given trip kills you, about the s…

A well-maintained (and well designed, but there's no reason to think the design was at fault here) bridge shouldn't collapse. Ever. "Appropriate maintenance" in this case would have been to periodically unclog the drains so the water can run off in a controlled fashion and not pool and corrode the supports. How expensive can that be? Instead, the bridge collapses (and they were lucky that no one was killed in the collapse), and they have to replace it for millions of dollars. Money saved on maintenance is the very definition of the proverb "penny wise, pound foolish" IMHO.

Re: Fern Hollow Bridge should have been closed years before it collapsed

#28

Post by shiroiushi »

rapsey wrote: post #17
m2f2 wrote: post #8

Same stuff for the Genoa, Italy bridge (Ponte Morandi). Everyone running on that would feel vibrations and "repairs" were just lipstick on a ugly face, until it finally collapsed, with 43 dead. Surprisingly, or not so, no one was found guilty, not even the inspectors that didn't report the ongoing damages, just because "it would be too costly to rebuild it, and profits of the highway company (1) in charge of it would…

Yet Italy spent years trying to put Adrian Newey in jail for building an f1 car involved in a fatal crash.

They also tried to put a bunch of earthquake scientists in jail for not predicting an earthquake.

Re: Fern Hollow Bridge should have been closed years before it collapsed

#29

Post by zeristor »

m2f2 wrote: post #8

Same stuff for the Genoa, Italy bridge (Ponte Morandi). Everyone running on that would feel vibrations and "repairs" were just lipstick on a ugly face, until it finally collapsed, with 43 dead. Surprisingly, or not so, no one was found guilty, not even the inspectors that didn't report the ongoing damages, just because "it would be too costly to rebuild it, and profits of the highway company (1) in charge of it would…

As the video states this was flagged by inspections 14 times over 7 years or so.

There's even inspection reports of one of the cross supports rusted through and disconnected, a cable taking some of the strain. At the very least the bridge should have just been closed, as unsafe.

Re: Fern Hollow Bridge should have been closed years before it collapsed

#30

Post by thaumasiotes »

dmurray wrote: post #12

If you knew all this, would you have avoided driving over the bridge? Would you have wanted the local government to close it indefinitely awaiting repairs? Let's say it would collapse with 100% certainty randomly in the next three years, and you're in the danger area for 2 minutes, with a 20% chance of fatality (in fact, nobody died). That's still around a one in 4 million chance any given trip kills you, about the s…

> Let's say [...] you're in the danger area for 2 minutes, with a 20% chance of fatality

> That's still around a one in 4 million chance any given trip kills you

That's a one in five chance that any given trip kills you, unless 20% means something very different to you than it does to me.

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