Baltimore's Key Bridge collapsed after being hit by cargo ship

6,455 Views | 53 Replies | Last: 7 mo ago by LPHA
BBRex
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AG
As I understand it, it's the weight of the anchor chain that helps hold the ship in place, not a grabbing action of the anchor (which is important, but like you would think). I don't think they could have released enough chain to make a difference.
maroon barchetta
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swc93 said:

NPR story reporter said the bridge did not have concrete bumpers or dolphins; that they were recommended to be added but something/something $$$.


Could the bumpers or dolphins have held up against that kind of speed/force?
Sweet Kitten Feet
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S
probably not. But they might've at least absorbed enough to spare the bridge. But that's a huge amount of force even at a slow speed so still might not have done any good.
rwtxag83
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Sweet Kitten Feet said:

rwtxag83 said:

C@LAg said:

maroon barchetta said:

How does that even happen in the 21st century?

Was there no pilot boat to follow?
they had two power outages.

lost engines or steering or both.

a pilot boat is not going to help in that case.
I'm wondering why they didn't drop anchor. Guy on TV said they did, but I'm thinking this should have happened much earlier. If they get power back up, they can just pull it back aboard.

Crazy.
At that weight, even at a slow speed dropping anchor isn't going to stop it on a dime. Also, dropping anchor isn't just flipping a switch. It's a manual process.
I'm no ship driver, but I have spent a fair amount of time at sea on warships. I didn't think it would stop it on a dime at all. I heard an interview today saying it would have taken at least 2000 yards of the anchor on the bottom to even have a chance at stopping it. It's a 1000 ft vessel, so even completely empty there's a lot of tonnage of momentum to stop. This vessel should have been 'light' relatively, given almost all the containers were empty, and it was headed to Sri Lanka with a buttload of empty containers to empty, and then load and make a turn back this way.

Dropping anchor would not be a quick fix solution, but IF the power interruption happened far enough back from the bridge, and IF they did drop anchor well ahead of this 2000 yard window I mentioned, maybe, just maybe, it would have bought them enough time to re-establish power and then go full reverse on the screws. I mean, if your powerplant is compromised temporarily, and your drift has a halfway decent chance of resulting in hitting the bridge support, what do you have to lose?

Seems to me just from watching video that all they did was try to get the engines under power ( granted, none of us were there, so all speculation). Why not drop anchor while you are doing so? Kind of a 'use every single resource available to avoid the worst case scenario' kind of approach.
Greater love hath no man than this....
JMac03
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AG
It stated on the news that they did drop anchor and called for a mayday. (Didn't read every single post). They did the anchor to try to slow down.
Sea Speed
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Yes you let out enough chain in relation to the depth of the water. Dropping anchor would have looked good for all the Monday morning qbs but maybe would have slowed the vessel a fraction of a knot? Not enough to make a discernable difference. While this shows a small craft and a line attached to the chain, the principle is the same. You generally are making sternway when anchoring ships to stretch the chain out.

rwtxag83
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BBRex said:

As I understand it, it's the weight of the anchor chain that helps hold the ship in place, not a grabbing action of the anchor (which is important, but like you would think). I don't think they could have released enough chain to make a difference.
Maybe, but right now the Master looks pretty stupid. They are at fault for causing a disaster that will cost literally hundreds of millions. I don't think he'd look very good if he said:

"We dropped anchor and just hoped it would be enough to stop',

but if he said:

'We dropped anchor at the first sign of power loss, and continued all other efforts to try to re-establish power and control of the vessel. I knew the anchor might not be enough to stop her, but we wanted to bring literally every resource at our disposal to bear on the problem'.

I think people would see this as a more complete effort at stopping the ship or minimizing the damage.
Greater love hath no man than this....
ABATTBQ11
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AG
How anchors work:

Hehateme1
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ABATTBQ11 said:

How anchors work:


Fascinating, thanks for this
Monkeypoxfighter
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The tin foil hats are out in abundance this morning on Facebook.
It only took me a year to figure out this place is nuts!
ABATTBQ11
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AG
He's got an amazing channel. I had one of his videos recommended one day and ended up watching everything he had.

Here's how ships stop:



Here's how rudders work:




According to a lot of stuff on his channel, the ship could have been sucked to the right by another channel of water it was passing creating a pressure differential on the hull. Also, if they managed to regain power and reversed thrust, ships with a single propeller can experience transverse thrust in reverse because of asymmetric pressure differentials on the hull from the water thrown off the propeller.
Shooter McGavin
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Monkeypoxfighter said:

The tin foil hats are out in abundance this morning on Facebook.
Lara Logan is laying out a pretty good little argument for this being foul play.
maroon barchetta
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Who?
Sweet Kitten Feet
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S
That girl's gone so far round the bend. Sad really
Sea Speed
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AG
Your stern walks to port or starboard depending on the way your propeller turns. When backing down it will turn one way and then once you have a stern way it will start going the opposite.

Additionally when navigating in narrow channels you get what is called bank suction or cushion. This effect is the entire premise of the Texas chicken in the houston ship channel.

The pressure wave that builds from your bow will push your bow away from the bank/another ship etc and your stern will generally be sucked in to it. You generally need to try and predict this or be ready for it so that you can use engines and rudder to counteract it. The deeper your draft/faster you're going/more turns on the engine/shallower the water the greater the effect.
ABATTBQ11
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Yeah he's got really good videos that explain all of that pretty well. I'd never put much thought into it until I watched his channel and found it all very fascinating.





Sea Speed
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I crash ships together for a living and it is wild to see the amount of interaction 2 ships will have, especially if it is a heavy job where I'm driving a loaded suez and a loaded vlcc. Lots of mass and I'm trying to crash them as slow as possible ha
Hehateme1
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Sea Speed said:

I crash ships together for a living and it is wild to see the amount of interaction 2 ships will have, especially if it is a heavy job where I'm driving a loaded suez and a loaded vlcc. Lots of mass and I'm trying to crash them as slow as possible ha
Just reading that reminds me of that snake farm song. Just sounds nasty
LPHA
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AG
Pretty much is
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