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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

#861

Post by unethical_ban »

sickofparadox wrote: post #429
boringg wrote: post #397

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…

It's likely that a lot of people don't understand just how huge these ships are. I'd imagine that much of HN doesn't have a ton of firsthand experience with shipping yards or even close friends/relatives that work on these things. In my experience, almost nothing hides just how large it is than a giant ship.

When I was a kid, we would go fishing off of pier near a port. The size of carriers and tankers is staggering. And if you get close enough to see numbers and lines near the front of the boat, you realize that fully loaded these things are 30 40 ft underwater.

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

#862

Post by marnett »

senectus1 wrote: post #845
samstave wrote: post #759

Earlier quoted context omitted.

Jeasus - seriously - if that was an inbound shipment then it would be worse - this appears to have been leaving - which would infer that the TEUs were more empty than full.

do they ever run these empty? I would expect they're as close to full as they can get in every trip. They'd be terribly inefficient ways to transport goods otherwise.

With what would they be filled with?

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

#863

Post by forgetfreeman »

ClumsyPilot wrote: post #857
forgetfreeman wrote: post #644

Earlier quoted context omitted.

Nope. The military, aerospace, and medical industries have all refused full automation in life-or-death situations with cause.

Isn’t that interesting when compared with ‘machines don’t make mistakes’ wisdom

You'd have to be either a complete headass fresh out of a coding bootcamp or carting around The Agenda That Ate Calcutta to fall for that line of bullshit. Anyone who's spent the wrong parts of their week debugging ought to intuitively grasp that machines are inherently error-prone.

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

#864

Post by boringg »

boringg wrote: post #397

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…

For an assumption to get a gauge of forces involved: Large cargo ship mass is 190,000 tons @ 8 knots (14.8 kph) - I end up with a Force of about 1.609 * 10^9 or 1.6 GN of force of impact assuming it stopped over a very short distance (1 M).

Force comparables (thanks GPT) for scale: Saturn V rocket thrust is about 34 GN on take off.

Earthquakes: early stage of the earthquake might have about 1 GN of force in build up.

Great pyramid of Giza is estimated at 50 GN of weight - so 1.6 GN could support a fraction of the weight.

Engineering machinery - some of the largest human machines such as mining or lifting can exert forces only in the MN so would need a 1000 machines to get up to a GN.

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

#866

Post by [deleted] »

Cheer2171 wrote: post #833
chx wrote: post #766

Earlier quoted context omitted.

> 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??

> just how unpopular would it be to abandon Baltimore?? You underestimate how much vitriol is coming from the Right about Democratic-leaning cities. Baltimore is 60% Black and voted 87% for Biden in 2020. Baltimore isn't on the top of the list of cities they like to claim are failures, but just wait. My dad is deep in the Right-wing media econsystem and he is convinced that the downtowns of Portland and San Francisco…

[deleted]

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

#867

Post by foobar1962 »

lotu wrote: post #587
araes wrote: post #541

Earlier quoted context omitted.

Current personal suspicion after watching your linked video (excellent discussion by the wgowshipping author) is: Catastrophic engine failure (1:24) causing wide scale power loss. No rudder control, rudder drift, and ship alignment drift (1:24-1:25:30) Power restored and ship reengages prop with bad ship/ruddder alignment (1:25). However, ship is now pushing itself into a further bad turn. Pilot likely stomps the bra…

> How many pilots, trained or not, really have any experience with a 100,000 ton ship in a crash situation with responses where seconds matter? I would expect anyone piloting such a ship in a harbor/under bridges. We requite airline pilots to train for many unlikely plane failures because the alternative is letting planes crash that we could have saved with better training.

> How many pilots, trained or not, really have any experience with a 100,000 ton ship in a crash situation with responses where seconds matter?

The crew would have know for several minutes that the collision was imminent. These things happen slowly, it wasn't like the bridge suddenly jumped out of the water unexpectedly in front of them. The tragedy is that the crew had no options to avoid the disaster.

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

#868

Post by lupire »

reactordev wrote: post #822
twic wrote: post #801

Earlier quoted context omitted.

The ship's managers (which I believe means the company which chartered it from its owners, and were operating it) say there were two pilots on board: https://www.synergymarinegroup.com/dali-imo-9697428/

Well then there were two pilots aboard to see it into the Chesapeake… Still, a diesel gen malfunction would render them useless unless one of them was a diesel mechanic as well (we sailors often have multiple credentials).

I don't think even the best diesel mechanic can fix it in 3 minutes.

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

#869

Post by lupire »

Amezarak wrote: post #612
pixl97 wrote: post #603

Earlier quoted context omitted.

Once the ship is under way I don't think the tugs hang around. They are just for the push away from the dock and initial turns.

It's very typical for pilots to be required for all entrance and egress from harbors, much more than the initial pushaway and turning but for quite a long distance through the channel.

Pilots or tugs?

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

#870

Post by exodust »

mkl wrote: post #82
TaylorAlexander wrote: post #66

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…

Not all bridges are this vulnerable to a single impact. This one, opened 12 years earlier, has a different style and mostly survived a cargo ship impact: https://en.wikipedia.org/wiki/Tasman_Bridge_disaster

Wikipedia is missing the iconic photo of the two cars hanging over the edge of the Tasman bridge.

> "the only thing that stopped the car from tipping over the edge was the casing of the automatic transmission, which grinded and gripped into the surface of the bridge."

https://www.carsguide.com.au/oversteer/this-hq-monaros-auto-...

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