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Baltimore's Key Bridge struck by cargo ship, collapses

wbaltv.com

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Re: Baltimore's Key Bridge struck by cargo ship, collapses

#271
post #7

Video here https://twitter.com/sentdefender/status/1772514015790477667

While this tweet is factual, be very careful with this account in general, is has turned from a good source to a very slanted and biased fake-news-accelerator.

Have any examples of fake news from that source we should be careful about?

Re: Baltimore's Key Bridge struck by cargo ship, collapses

#272

Somehow I find it surprising how completely the bridge collapsed after the damage. I understand that a container ship collision is serious, but you could imagine a scenarios where the bridge slumps or buckles but doesn’t just disintegrate like that. It’s surprising that ships capable of doing this damage were probably regularly driving past it, and its safety as a thoroughfare depended entirely on those collisions no…

The Bay Bridge in SF has been hit by numerous ships (as large as tankers)

Re: Baltimore's Key Bridge struck by cargo ship, collapses

#273
post #136

Not that it matters to anyone else, but having driven across that bridge dozens of times with my kids, this is just shocking. It’s one of the main corridors in the area. Thank god it happened in the middle of the night, though that’ll be no consolation to the families of those who may have died.

Local to the area. This was devastating news to wake up to. I don't know what's wrong with me but seeing this and knowing there were casualties made me cry. Edit: Maybe I'm just tired and need more sleep.

> I don't know what's wrong with me but seeing this and knowing there were casualties made me cry.

I think that's called "having feelings". Nothing wrong with it.

Re: Baltimore's Key Bridge struck by cargo ship, collapses

#274
post #159

Earlier quoted context omitted.

You could try to avoid collisions with barriers, or make the bridge fail differently (only a few spans), or make it tolerant to a single support failing. But you need a pretty beefy steel beam to survive a direct hit by... Uh... 200,000t(??) traveling even at a slow jogging pace. (And then it transfers the energy into the rest of the bridge, which will very much not like it). I guess we can be happy failure like this…

Some other bridges have barriers around, but not connecting to the pylons.

Those are great for little boats like one of those superyachts. They become dominoes that hit before a boat like this: https://www.vesselfinder.com/?imo=9697428

Re: Baltimore's Key Bridge struck by cargo ship, collapses

#275
post #165
post #153

Earlier quoted context omitted.

Because the Port of Baltimore is a very major port, and not allowing ships under it really isn't an option. Vertical clearance for ship traffic might have been the reason this kind of bridge was built in the first place. Otherwise, something lower and more causeway-like might have been sufficient.

If it's a very major port, they can afford to make it a tunnel.

The Patapsco is much wider here than at the locations of the two tunnels. It would have been a much bigger and more expensive project to build a tunnel that long.

Re: Baltimore's Key Bridge struck by cargo ship, collapses

#277
post #208

Earlier quoted context omitted.

Interested in this claim, because it sounds about right, except that I can’t name a bridge constructed in the past 50 years. The bridges we can all name are pushing 100+ right?

Mackinac Bridge is somewhat famous, built in the 1950s. They more or less do continuous maintenance during the warmer months of the year. (So older than 50, but younger than 100)

Michiganders will also know the "Z Bridge", completed in 1988

https://en.wikipedia.org/wiki/Zilwaukee_Bridge

Sticking with the mid-western therme, the Chicago Skyway was built in 1958

Re: Baltimore's Key Bridge struck by cargo ship, collapses

#278

Somehow I find it surprising how completely the bridge collapsed after the damage. I understand that a container ship collision is serious, but you could imagine a scenarios where the bridge slumps or buckles but doesn’t just disintegrate like that. It’s surprising that ships capable of doing this damage were probably regularly driving past it, and its safety as a thoroughfare depended entirely on those collisions no…

> It’s surprising that ships capable of doing this damage were probably regularly driving past it, and its safety as a thoroughfare depended entirely on those collisions not happening.

There are cities with skyscrapers near airports, which depend on the airplanes not hitting the skyscrapers.

Re: Baltimore's Key Bridge struck by cargo ship, collapses

#279

Earlier quoted context omitted.

At least in the links with the video now you can see that the container ship directly hits one of the two main (and in the central area only) pillars completely collapsing it. No matter(1) the engineering there is no pretty much way to not lose the whole large middle area and left area leading to the destroyed pillar in that situation. Such a collapse crates so much force (tension vibrations etc.) so that the collaps…

It certainly does not seem reasonable to design a bridge pillar to withstand a direct impact from a massive cargo ship. But I guess I thought that maybe there was... typically some kind of earthen buffer around the pillar to prevent such an impact? That's probably impractical too, I guess. I guess I just didn't realize ~$1bn bridges were one fluky ship accident away from total collapse at any given time. I think mayb…

When Florida's Sunshine Skyway bridge was partly collapsed by a similar incident in 1980, the replacement bridge was built with a series of "structural dolphins" and concrete barriers to protect against ship strikes. You can see them in the image linked below:

https://en.wikipedia.org/wiki/Sunshine_Skyway_Bridge#/media/...

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