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Baltimore's Key Bridge struck by cargo ship, collapses

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

#791

How long did this event last from start to finish? Just wondering why there are cars still driving through the bridge moments before impact.

Supposedly the ship issued a mayday prior to losing power and hitting the bridge, so they were able to stop traffic and limit the number of people on the bridge during the accident. Most of the people who went down with it were construction workers.

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

#792
post #721

Earlier quoted context omitted.

The boat changes direction after impact with the bumper

It was a massive boat. They don't change direction very easily.

Well engineered small things can redirect a moving thing several orders of magnitude more massive. Consider guardrails on the side of a road; those guard rails might be less than 100 Kg but together they're rated to redirect the force of a car weighing thousands of Kg traveling at tens of K/h. That's a lot of force to redirect for such a small and cheap barrier; imaging what a more expensive and larger barrier can do.

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

#794
post #766
post #753

Earlier quoted context omitted.

I'm kind of confused how a President can promise something like that. He doesn't have any power to appropriate money, and given his party's lack of control of Congress, I'd argue he can't promise anything. Not to mention that one can scarcely find a "bluer" area than Baltimore -- I would assume that the most proudly right-wing politicians would be more than happy to let Baltimore suffer to score points with their pol…

> It's my intention that the federal government will pay for the entire cost of reconstructing that bridge and I expect the Congress to support my effort This is what he said. I would expect Congress to play along too -- just how unpopular would it be to abandon Baltimore??

Republican side probably doesn't care; Maryland voted 65% for a democratic party president.

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

#795

This is a tragedy for those involved. My rough calculus points that the amount of force of this collision is on par with a large scale natural disaster. Everyone being surprised at the bridge collapsing needs to reconcile with the amount of force that struck the bridge - it is a truly significant amount of Newtons that hit the bridge. More than a train going from full speed to a full stop. Unbelievable amount of forc…

> More than a train going from full speed to a full stop.

I wonder. This ship might have massed about ten times a typical freight train on the heavy side, but the train is going to be moving a lot faster than a ship navigating in port, right?

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

#796

Earlier quoted context omitted.

Why don't they just fine the shit out of that rocket boat company every time they pull that outrageous prank? Or throw someone in jail. Who thinks that is in any an ok prank? Can you imagine someone doing that in a car? Its just a prank bro!

I mean, I'm not the lawyer, my brother is. But I'll speculate all the same. I don't think that they are actually doing anything illegal [0]. It seems to be perfectly fine to pilot your boat anywhere you want to. Even if that means it looks like you're gonna run into the pier. It's not like they ever actually did run into the pier anyways. Also, per other conversations with my brother, maritime law is not like 'normal…

What you describe sounds like international waters, close enough to the pier to matter would be within US territorial waters. So if the relevant laws are not there it is purely a domestic issue.

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

#797

This is a tragedy for those involved. My rough calculus points that the amount of force of this collision is on par with a large scale natural disaster. Everyone being surprised at the bridge collapsing needs to reconcile with the amount of force that struck the bridge - it is a truly significant amount of Newtons that hit the bridge. More than a train going from full speed to a full stop. Unbelievable amount of forc…

> I am also a bit surprised at how many people don't grasp this or grasp engineering, magnitude of forces and design principles.

Who are you even referring to? Are you just inventing a population of people in your mind to flex against here? Trust me, people get it.

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

#798

The design of the Chesapeake Bay Bridge-Tunnel, specifically the tunnel part, makes a lot of sense now. Imagine a US navy port (Norfolk) being inaccessible if this happened there.

This was also a major concern around the construction of the Golden Gate bridge; that during a time of war an enemy could have destroyed it to trap a large portion of the Navy's Pacific Fleet in the bay.

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

#799

Earlier quoted context omitted.

I have no idea what any of this means.

IT was a glitch in posting... I was responding to multipile threads and somehow my comments merged...

No part of that comment made sense. I don't think the problem was that multiple comments merged.

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

#800

Earlier quoted context omitted.

It's somewhat counterintuitive how much energy can be in something moving so slowly. I say somewhat, because when you're up close it's much more obvious, but you're right that on a video it doesn't look like much.

This disconnect happens with boats quite a lot. For example, I can, by myself, pull a 45 foot grand banks trawler in shallow water. I know because I've done so. But at even very low speeds, I cannot stop it from hitting a pier. I have not tried to do this, but every harbor master has a bunch of stories about people trying to do so and getting a leg or an arm or something squished and pulverized. People who are not bo…

Landlubbers are accustomed to momentum (p = mv) behaving in a certain way instinctively from years of experience, where the heavier something is, the more frictional force against it from the ground, and therefore the mass behaves a certain way. This breaks down once the expected friction changes a lot, e.g. trying to stop a moving car or, like you said, a boat in water. I'd imagine it's the same thing in space, where a slowly-moving but massive object would surprise someone at their inability to stop it.
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