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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

#151

Earlier quoted context omitted.

This is actually part of the PROBLEM - with so many bridges on the "worst possible category" it becomes a bridge who cried wolf scenario. There is no way to highlight "yeah this one is going to fall down tomorrow" if the worst you can do is mark it "this bridge bad like 42k others". You need some form of a "stop ship" where inspectors get some number of "no way, close this entirely" that they can use without repercus…

There's a road near me that's been replaced by a large 4 lane state route. There's almost no reason to drive it as there are no houses or farm access. The bridge is being completely replaced. The road is closed during construction, and I think the only people impacted by it are the recreational bikers. A boondoggle while other bridges around the country are in dangerous disrepair. I wish we knew there was a sensible…

Yes! I want a cost benefit analysis and to ask every stakeholder imaginable for any sort of road repair or expansion. The fact that not every repair or expansion has a single improvement for non car users is pitiful.

We need to hold road infrastructure to the same consideration as we do transit and rail. If we didn’t give it unlimited funding, then it would already be doing this.

We are wasting trillions and losing so much economic growth by doubling down on a bad investment year after year for decades. Imagine if this money was put into education or healthcare or transit. We’d actually have a net benefit!

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

#152

Earlier quoted context omitted.

This is actually part of the PROBLEM - with so many bridges on the "worst possible category" it becomes a bridge who cried wolf scenario. There is no way to highlight "yeah this one is going to fall down tomorrow" if the worst you can do is mark it "this bridge bad like 42k others". You need some form of a "stop ship" where inspectors get some number of "no way, close this entirely" that they can use without repercus…

There's a road near me that's been replaced by a large 4 lane state route. There's almost no reason to drive it as there are no houses or farm access. The bridge is being completely replaced. The road is closed during construction, and I think the only people impacted by it are the recreational bikers. A boondoggle while other bridges around the country are in dangerous disrepair. I wish we knew there was a sensible…

A big part of that is who pays - state and federal dollars that are unused go away, so they often find a program that can use it, even if it's not the best use of funds locally.

Local roads often don't qualify, but state and federal highways do.

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

#153

Earlier quoted context omitted.

No, they were jailed because they reassured the population that there was no risk of earthquake, when there absolutely was. That's very different.

Still ridiculous, though. Do doctors in Italy go to jail for giving false negative cancer diagnoses? Can I sue the weather man when I get struck by lightning when they said there's no chance of rain? Maybe next time the public should interpret the seismographs themselves. Edit: It was eventually overturned [1]. Still, a shocking indictment of the court system. 1. https://www.theverge.com/2014/11/11/7193391/italy-judg…

> Still ridiculous, though. Do doctors in Italy go to jail for giving false negative cancer diagnoses?

If there were strong indications of cancer and a doctor blatantly ignored it? An argument could be made that's negligence causing death.

Clearly some degree of negligence is absolutely criminal when people's lives are on the line. Maybe you don't agree where that line was drawn in this specific case, but that's not an argument that no such line exists.

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

#154

Earlier quoted context omitted.

So the industry's rating system maps this bridge - totally fucked, key structural members rusted away entirely, others with large, clearly visible holes right through important points, weakened to the point it ended up falling down - to "structurally deficient" and then maps "structurally deficient" to "not necessarily unsafe" ? Kinda makes me think George Carlin was on to something with his hate of soft, euphemistic…

That's one of the points in the video: the paperwork tends to obscure the state of the system to decision makers. It's easy for the bridge inspectors (or even a random member of the public) to see that it needs to be closed down and repaired, but it's not what the decision-makers see: they see a 100-page report with a long list of action items, many of which are not actually incredibly urgent, much like every other b…

That's related, but it's not my point. Saying "decision-makers miss details in 100-page reports" makes it sound like the report is merely too thorough, and the inspectors did too good a job.

My point is the report's summary could have said "This bridge will fall down within 3 years" instead of obscuring the with vague, watered-down jargon like "structurally deficient"

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

#155
post #59

Earlier quoted context omitted.

Yeah, that sounds really strange. Not sure how it is elsewhere in Europe, but in Finland whoever builds it, maintains it. Intercity road and rail networks are all owned and managed by the state, and that’s actually how the equivalents of "road" and "street" are defined within the field: anything owned by the state is a road, anything owned by the municipality is a street. In recent years there have been plans to "bou…

Finland joined the EU too late and too rich, perhaps. In other countries the EU was the main source of funds for building motorways, but doesn't own them or maintain them.

Hmm, perhaps. These days you can still get 30-50% from the EU but essentially only if it’s part of TEN-T or maybe some Green Deal related project.

The core network of major roads in Finland can be kept in a good shape, the issue is largely the thousands of kms of secondary and tertiary roads in the middle of nowhere that have too little traffic to be any sort of a maintenance priority, or to be eligible for EU funding. But you can’t really help it in a country that’s as sparsely populated as Finland outside major urban areas.

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

#156
post #137

To prevent this from happening in the future, I would give the inspectors the right to immediately close a bridge when it got to be this bad. If the owner forcibly reopened it, they would lose any insurance coverage on it (be totally liable for consequences).

Nobody would hire the ‘assertive’ engineers or firms, so it’d be a very rarely used power.

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

#157

For context, there were 42,391 structurally deficient bridges in 2023.[0] 16 of the worst are in LA county and several see 300k trips daily, including one carrying the 405.[1] 0. PDF https://artbabridgereport.org/reports/2023-ARTBA-Bridge-Repo... 1. https://artbabridgereport.org/state/ranking/top-bridges EDIT: States with the least % of SD bridges: AZ, NV, TX, DE, and UT. WV and IA have the most at almost 20% SD brid…

This is actually part of the PROBLEM - with so many bridges on the "worst possible category" it becomes a bridge who cried wolf scenario. There is no way to highlight "yeah this one is going to fall down tomorrow" if the worst you can do is mark it "this bridge bad like 42k others". You need some form of a "stop ship" where inspectors get some number of "no way, close this entirely" that they can use without repercus…

I mean, it's not even remotely legal but some TNT can shut down a bridge and highlight that it needed help...

And it can be done in a way that there isn't a bus on the bridge when it collapses.

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

#158

For context, there were 42,391 structurally deficient bridges in 2023.[0] 16 of the worst are in LA county and several see 300k trips daily, including one carrying the 405.[1] 0. PDF https://artbabridgereport.org/reports/2023-ARTBA-Bridge-Repo... 1. https://artbabridgereport.org/state/ranking/top-bridges EDIT: States with the least % of SD bridges: AZ, NV, TX, DE, and UT. WV and IA have the most at almost 20% SD brid…

Managing structurally deficient bridges is more problematic in places with winter or at least more varied weather (like Pennsylvania).

Just like this bridge, the big problem is that something happens and degradation switches from "slow but manageable" to "Oh, shit, suddenly that beam is gone and this bridge might collapse".

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

#159

Earlier quoted context omitted.

Annual Rainfall per square inch seems like a relevant factor though.

Texas averages 36 inches of rain and 2 inches of snow each year. Ohio gets 40 inches of rain and 28 inches of snow.

> Texas averages ... 2 inches of snow each year.

Really? That does not comport with my experience growing up there.

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

#160
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 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 Or how about let's say it would collapse with 100% certainty randomly in the next three years, and a school bus with twenty kids in it drives over the bridge twice a day, with each child facing a 20% chance of fatality. ‘I probably won’t be the one who dies whe…

School buses are never a useful way to think about risk. You might not be intending it, but this is a cheap manipulation technique.

Bridges sometimes fail catastrophically, with risk to life. Modeling risk is a necessary way to consider the costs of mitigation.

Leaving aside the poor helpless babies, what metric would you suggest?

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