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Quoted: Well since it pretty well grounded I don't think static discharge is much of an issue. Last I checked water is not an electrical insulator. View Quote View All Quotes View All Quotes Quoted: Quoted: I wonder what prevents lightning or a static charge in general from pre-blowing the blow. Well since it pretty well grounded I don't think static discharge is much of an issue. Last I checked water is not an electrical insulator. That's the problem, elevated portion with ground potential will be juicy paths for lightning discharge, and if they've already got the detonators (or wires for them) on the charges, they could easily blow due to the high gradient of voltage traveling down the truss through the detonator wires to the water and into the river bed. The charges without detonators are a bit more immune (as long as wires for detonators aren't stopping at the charge), and they usually don't add the detonators until shortly before the planned detonation time, when all the radios and other RF devices need to be turned off to avoid tripping detonators with long lead wires (aka "antennas"). |
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Quoted: That's the problem, elevated portion with ground potential will be juicy paths for lightning discharge, and if they've already got the detonators on the charges, they could easily blow due to the high gradient of voltage traveling down the truss through the detonator wires to the water and into the river bed. The charges without detonators are a bit more immune, and they usually don't add the detonators until shortly before the planned detonation time, when all the radios and other RF devices need to be turned off to avoid tripping detonators with long lead wires (aka "antennas"). View Quote Serious question: is the insertion of the detonators usually a junior-level position or one that'd given to let's say more...expendable guys? |
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Quoted: Serious question: is the insertion of the detonators usually a junior-level position or one that'd given to let's say more...expendable guys? View Quote View All Quotes View All Quotes Quoted: Quoted: That's the problem, elevated portion with ground potential will be juicy paths for lightning discharge, and if they've already got the detonators on the charges, they could easily blow due to the high gradient of voltage traveling down the truss through the detonator wires to the water and into the river bed. The charges without detonators are a bit more immune, and they usually don't add the detonators until shortly before the planned detonation time, when all the radios and other RF devices need to be turned off to avoid tripping detonators with long lead wires (aka "antennas"). Serious question: is the insertion of the detonators usually a junior-level position or one that'd given to let's say more...expendable guys? I'm not an expert in this area, just played a bit. Adding detonators is pretty safe. They don't go off randomly unless they're really old, the way old dynamite found in sheds is unstable to the point of just throwing it and having it hit the ground makes it go boom. Today's explosives and detonators are very hard to get to go high order unintentionally. C4 just burns and doesn't detonate unless it gets a big shock while burning, hence the need for detonators to get a big enough shockwave started to initiate the charge. Detonators are equally protected so that only a good non-accidental current through them will make them blow, they're the force of a big firecrackers or 12ga boom, would blow fingers off if held tightly in hand but not a super big explosion, they're the bridge between the very stable explosive and the unpredictable outside world. Long wires acting as antenna could get enough of a static potential to make them accidentally fire but that's not an easy task, they're made to require a pretty good current to get to go bang to avoid that exact situation, also not super sensitive to shock if dropped. It's only when they're combined with the charge does it get scary fast. It's a job that anybody can do but usually a senior EOD guy will go around and ensure the charges are in the right spot and tamped for shape cutting charge before they actually trip them all in a particular order, which is planned by somebody with a lot of experience in demolition, to time delays between different charges to get the thing to fall exactly where intended and not hurt any unintended targets with shrapnel at the same time. |
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Looks like it's scheduled for 5pm eastern time today.
https://www.cnn.com/2024/05/13/us/baltimore-bridge-collapse-demolition-monday/index.html |
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Are there any alternate live feeds? The Minorcan Mullet is buffering terribly.
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LIVE: Controlled demolition at Baltimore bridge collapse site |
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Live from Baltimore |
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Well that was cool. Can't believe I just happened upon that live. Big bada boom.
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It almost looked like the delay sequencer didn't work and all the charges blew at once.
...unless it was planned that way. |
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Quoted: They are probably going to have to hit it again. View Quote View All Quotes View All Quotes yeah, it didn't do anything but get the weight off of the ship so they can remove all of the lose beams and move the ship out of there and cut up the remaining part of the bridge safely. |
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That was pretty neat. Did not notice any change in the waterline, so not sure if they need to remove more concrete or possibly the roadway to get the ship out of the mud.
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Do we need to revisit all the predictions on when this would have been cleared and new bridge up and running? Im going to guess there some really far off estimates.
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I would call it a success.
They clearly removed the tension from the beams, got the harder to reach areas off the boat. The pieces on the boat are cut strategically to lift off so they can clear the bow. They can cut the remaining section in the water and pull the major pieces from there. |
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some videos from different angles
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Going to take more than 2 days to get all that crap off the ship, which they predicted what it would take after the kaboom.
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To be fair, I don't have any idea what I'm looking at, but it sure seems like that truss could have been torched off just as easily as it was blown off.
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Quoted: To be fair, I don't have any idea what I'm looking at, but it sure seems like that truss could have been torched off just as easily as it was blown off. View Quote Tension makes it very dangerous. If you’re up in a man lift, on a boat. And that beam suddenly whips. Where ya going? Even if it doesn’t hit you but hits the machine. |
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Key Bridge EXPLODED Off MV Dali Ship | Baltimore Bridge Collapse |
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I think they are planning on leaving the roadway on the bow and removing it at the dock.
I wonder if this is because the docks presumably have much higher-capacity cranes. |
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Unified Command officials explain how controlled explosives were used in demolition of Key Bridge |
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Quoted: I think they are planning on leaving the roadway on the bow and removing it at the dock. I wonder if this is because the docks presumably have much higher-capacity cranes. View Quote In the YouTube I posted, the Army Colonel says they will remove as much of the wreckage on the bow as needed to refloat the ship along with anything that's not stable enough for the ship to move with it still on there. Coast Guard Captain says detonation went as planned, separated the span into 2 pieces along with other pieces falling away from the ship. Water ballast will be removed to allow her to float on her own and they plan to move the ship as soon as possible. Maybe in next 2 days. Once pier side they plan to remove the remaining roadway sections and other debris and some containers. Do some repairs and then move the ship elsewhere for larger repairs. Majority of containers will remain onboard so it rides low enough to get under bay bridge. I believe he said it will move to Norfolk when it leaves Baltimore harbor. |
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They sent a text alert out to the area (I was near the Magothy river at the time) to warn of the loud explosion
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Quoted: In the YouTube I posted, the Army Colonel says they will remove as much of the wreckage on the bow as needed to refloat the ship along with anything that's not stable enough for the ship to move with it still on there. Coast Guard Captain says detonation went as planned, separated the span into 2 pieces along with other pieces falling away from the ship. Water ballast will be removed to allow her to float on her own and they plan to move the ship as soon as possible. Maybe in next 2 days. Once pier side they plan to remove the remaining roadway sections and other debris and some containers. Do some repairs and then move the ship elsewhere for larger repairs. View Quote Was she ballasted as a means of keeping her bow pinned to the sea bed or was that normal voyage ballast? |
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Quoted: Was she ballasted as a means of keeping her bow pinned to the sea bed or was that normal voyage ballast? View Quote View All Quotes View All Quotes Quoted: Quoted: In the YouTube I posted, the Army Colonel says they will remove as much of the wreckage on the bow as needed to refloat the ship along with anything that's not stable enough for the ship to move with it still on there. Coast Guard Captain says detonation went as planned, separated the span into 2 pieces along with other pieces falling away from the ship. Water ballast will be removed to allow her to float on her own and they plan to move the ship as soon as possible. Maybe in next 2 days. Once pier side they plan to remove the remaining roadway sections and other debris and some containers. Do some repairs and then move the ship elsewhere for larger repairs. Was she ballasted as a means of keeping her bow pinned to the sea bed or was that normal voyage ballast? I took it to mean they added water ballast to keep it down and so it didn't pop back up when the weight of the bridge span was removed during the detonation. |
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Quoted: Tension makes it very dangerous. If you’re up in a man lift, on a boat. And that beam suddenly whips. Where ya going? Even if it doesn’t hit you but hits the machine. View Quote Exactly. Nothing more unsettling than cutting a beam and seeing the gap start opening or twisting, and that can happen on structures that look completely safe. Something like that? Fuck that. It's basically Jenga with your life. |
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I'm thinking that once the Dali is out of there, the pace will pick up considerably.
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That's why they had a pro set the explosion. Just enough to relieve the tension on that piece of the bridge. Going in there to cut it manually would put people at risk unnecessarily. They did this correctly. ETA: This would not be like running a chainsaw and reading the tension on what you're cutting. |
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Has the crew been on board this whole time? I know they're used to being on the ship for extended periods, but you'd think with an extended period of not going anywhere or having anything to do they'd start to get a little stir crazy.
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Quoted: Quoted: Has the crew been on board this whole time? I know they're used to being on the ship for extended periods, but you'd think with an extended period of not going anywhere or having anything to do they'd start to get a little stir crazy. The crew has never left the ship. I wonder what they've been doing. Do they have internet? |
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Quoted: They moved the big floating crane in to work on the bow area. https://www.ar15.com/media/mediaFiles/367483/floating_crane-3213999.png View Quote That pic really shows just how much weight is on that front bow section. |
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