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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

#211

Post by Hamuko »

Retric wrote: post #187
HlessClaudesman wrote: post #170

Earlier quoted context omitted.

On a long enough timeline we all get rammed by a container ship. I would be interested to know some calculations with factors like: expected bridge lifetime, chance of being rammed per year, cost of making supports strong enough plus an extra safety margin to survive maximum ramming force, cost of having major commercial shipping route unusable for an extended period.

Bridges only last for roughly 50 years. Considering such collisions are rare enough to make the news as a memorable event you can workout for yourself that the odds are quite low over a bridges lifespan. They are designed to withstand smaller boat impacts because they occur relatively frequently, but cost vs benefit on rare events that are difficult to mitigate is quite different.

Doesn't the US have a problem with bridges exceeding their expected service lives?

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

#215

Post by mango7283 »

yosame wrote: post #197
Retric wrote: post #187

Earlier quoted context omitted.

Bridges only last for roughly 50 years. Considering such collisions are rare enough to make the news as a memorable event you can workout for yourself that the odds are quite low over a bridges lifespan. They are designed to withstand smaller boat impacts because they occur relatively frequently, but cost vs benefit on rare events that are difficult to mitigate is quite different.

Do you mean 50 years without maintenance? I would be shocked if major bridges weren't designed to last indefinitely.

I can think of at least 5 famous bridges that are way older than 50 years...

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

#216

Post by SapporoChris »

vik0 wrote: post #204

[flagged]

I am thinking that more information is needed before charges should be brought and if charges are brought then perhaps there should be a trial. I know it's popular to judge someone based on a limited amount of media, but I think it's a highly unfair act.

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

#217

Post by mezzman »

mcv wrote: post #165
rpeden wrote: 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.

However hazardous cargo is not allowed in tunnels so bridges like this one are the only way hazmat can be transported over water crossings.

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

#218

Post by SonOfLilit »

mvdtnz wrote: post #147
armchairdweller wrote: post #133

Earlier quoted context omitted.

Thanks! So why are huge—ass container ships allowed to navigate underneath fragile public bridges with single points of failure? The not unlikely worst case is that the ship is out of control for some reason…

Not unlikely? Can you point us to all the other times this has happened? You must know of several given your knowledge of how obviously likely this is.

Downvoted for unkindness towards internet stranger.

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

#219

Post by ithkuil »

kwhitefoot wrote: post #183
ithkuil wrote: post #180

Earlier quoted context omitted.

“Any idiot can build a bridge that stands, but it takes an engineer to build a bridge that barely stands.” And in practice only bridges that "barely" stand are economically viable

> only bridges that "barely" stand are economically viable That really depends on what is counted as part of the economy and who is doing the valuing.

well, "economically viable" doesn't necessarily mean scraping the bottom.

For example the great pyramids of giza are very solidly built. You certainly don't expect that level of build for every commercial or residential building out there.

Now, on the other end of the spectrum you can have buildings that can collapse on minor earthquakes.

There is a balance somewhere in the middle.

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

#220

Post by mopenstein »

bombcar wrote: post #138
armchairdweller wrote: post #133

Earlier quoted context omitted.

Thanks! So why are huge—ass container ships allowed to navigate underneath fragile public bridges with single points of failure? The not unlikely worst case is that the ship is out of control for some reason…

Because bridges over harbors are quite common an incidents like this are rare.

All roads should be underground! What if a plane crashes into a surface road? Or a meteor? Somebody think of the children!
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