1 in every 13 bridges in America is in 'poor' condition | Hacker News Reader

1 in every 13 bridges in America is in 'poor' condition

cnn.com

29 pointsLinuxBender21 comments

There is no bridge design that can be practically created and stop a multi ton shipping vessel. If you want to design something that can't then the solution would be to create a underground tunnel instead and this is much more expensive such as the channel tunnel https://en.wikipedia.org/wiki/Channel_Tunnel#:~:text=The%20C....

There are already two tunnels underneath Baltimore Harbor. When they built the Key Bridge, they didn’t have the money to build another tunnel.

Yeah the condition is irrelevant there, bad photo/timing for this article. Just trying to drum up fear.

I would describe that article as more of a call-to-action than drumming up fear. The article is quite clear that the problem in this particular case was due to design. On top of that, there was no suggestion that it was a faulty design. Rather, it's design does not reflect the realities of today.

I am not suggesting the article is perfect. There are lingering questions about which types of bridges fit in that 7.5%. Not all bridges have to deal with shipping traffic, heavier vehicles, or even more traffic. There are also questions as to why such large ships were permitted to pass under the bridge if it did not fit the design parameters of the bridge. But that is more indicative of an incomplete analysis rather than of fear mongering.

That bridge brand new, same result.

People see the headline and the image and walk away misinformed.

These ships have the mass of a skyscraper. Building a bridge you can throw a apartment building at doesn't make sense even if it was possible.

If we can't find crews who can manage this, we may need to pay them more and have higher standards for them.

This is a ship problem not a bridge problem.

Situations like this might be the best time to make meaningful change. The "outcome to avoid" is front and center in everyone's mind, but no decision makers were at fault.

If this was a bridge collapse that could have been prevented with proper maintenance, there would be a lot more panic-induced buck passing.

EDIT: nevermind the article is terrible

The above post is somewhere between flat out wrong and malicious misinformation.

One can easily reinforce the pries of the bridge to ensure that any ship is deflected. The Francis Scott Key Bridge didn't implement these because it was deemed too expensive.

You have a funny definition of easily. The impact force has been estimated as between 120MN and 230MN. I doubt there exist many bridges that can take that hit. The kind of ship impact protection that bridges usually have are not built to take a 150000t ship at 8kn.

Bridges can be designed to handle that kind of collision. This article discusses some of the ways it can be done [1].

[1] https://www.cbsnews.com/news/how-to-protect-bridges-from-shi...

From the article :

Theoretically, you could build a structure that would never fail, but you'd have to put infinite money into it. For a critical bridge of this type, we would consider an acceptable chance for failure to be 1 in 10,000 years.

And at that point why not do a cost benefit analysis of a tunnel?

I’m neither an engineer nor an architect, so this may come off as incredibly naive, but why wouldn’t layers of reinforcement — eg a retaining wall or guardrail — some distance out and around the main pillars help mitigate this kind of risk?

It would. Places, where rivers freeze, manage to build bridges that do not get crushed by the moving ice using this technology.

The amount of force involved is much greater than involved with moving ice.

I wish there was a good way to evaluate this claim. It comes from the American Society of Civil Engineers. I have nothing against them, but they are self-interested in this being a large number.

The Key Bridge was structurally fine, but needed better protection so today’s ships couldn’t hit the bridge.

Poor doesn't mean there's a significant risk of collapse, but replacements can take years and the bridge is approaching its end of life without corrective action. Even bridges in critical condition can be used safely with proper monitoring, just not for very long. https://en.wikipedia.org/wiki/National_Bridge_Inventory

  POOR CONDITION - advanced section loss, deterioration, spalling or scour.

  SERIOUS CONDITION - loss of section, deterioration, spalling or scour have seriously affected primary structural components. Local failures are possible. Fatigue cracks in steel or shear cracks in concrete may be present. 

  CRITICAL CONDITION - advanced deterioration of primary structural elements. Fatigue cracks in steel or shear cracks in concrete may be present or scour may have removed substructure support. Unless the bridge is closely monitored, it may be necessary to close the bridge until corrective action is taken. 

  "IMMINENT" FAILURE CONDITION - major deterioration or section loss present in critical structural components or obvious vertical or horizontal movement affecting structure stability. Bridge is closed to traffic but corrective action may put back in light service.

Just reading the article, the Key bridge was graded in Fair condition.

There is no claim the bridge condition contributed to it collapsing when hit by a large cargo vessel.

The ASCE report referenced (and linked to) in the article is 3 years old https://infrastructurereportcard.org/cat-item/bridges-infras... (2021 Report Card for America's Infrastructure). Their data comes from the US Department of Transportation.

So there is no self-interest here, really.

You must be a software engineer to not understand that other engineering professions are actually professional. Which means that they have actual ethical standards which they must adhere to or have their credentials revoked.

The USA no longer does anything without a series of catastrophes in a row.

aka crisis-driven

Because politicians there is no reward for wanting to invest and preempt failures, whether it is bridges or healthcare or pandemics.

Now if it was preparing for a future imaginary war, spend the entire GNP and then some with half the public's blessing.

So politicians maybe need to sell everything as a war and have the military do it.

When the American congress was debating their infrastructure legislation, a reason was that bridges and dams needed a lot of investment and improvements. That legislation became law, but how long until the money flows to the improvement projects?

I found the report card from the structural engineers much more interesting than the article itself, but I'm glad the article was posted because I wouldn't have know about it otherwise.

https://infrastructurereportcard.org/cat-item/bridges-infras...

If I have a thought about this, it's that so much depends on what it means to be labeled "poor". My first assumption is that that means "about to fall down", but that's not necessarily the case.

The report also has this paragraph:

> Encouragingly, as of 2019, just one in 13, or 7.5%2 of highway bridges were designated structurally deficient, or poor, representing a significant improvement from 12.1% recorded a decade ago. Also encouraging is that the total percentage of bridge deck area that is classified as structurally deficient, or poor, has decreased over the past several years, totaling just 5.5% in 2019, compared to 6.3% in 2016.

... which is much less troubling than the headline. My takeaway is that things have actually improved quite rapidly, given the type of work and the speed of government.

As one might cynically presuppose from an organization of professional engineers releasing a report card on bridges, the recommendation turns out to be "we sure do need to spend a lot more money on bridge engineering". That doesn't mean it's not the case, I'm sure it is, but I wonder what it would take for them to release a report concluding that everything is great, and you could actually give us less money if it would help balance the ol' checkbook.

It should be like 1 in 50 probably according to my gut feeling of bridges should stand 50 years before refurbished.

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