Bridge Collision

[hockeyrobot]

https://x.com/BNONews/status/1772515766929097088?s=08

A freighter collides with and destroys Francis Scott Key Bridge in Baltimore.

We'll I'm never driving on a bridge again. This is absolutely terrifying.

[Axeman33]

I am just watching this now. My cousin sent me a PM on facebook with the video earlier and at first, I thought it was a hoax until I see the major news agencies carrying it.

Crazy.

As I type this, CNN is reporting 2 rescued and there's at least 7 people missing. The only shining light is that this happened so early in the morning and there wasn't as much traffic as normal on the bridge at the time of the collision.

[Axeman33]

As someone who's spent over 20 yrs in the Navy, I can only imagine there had to be a mechanical rudder failure of some sort to cause this. Apparently this ship was leaving harbour on it's way out to sea. There would have had to be a Baltimore Pilot on board every ship coming in and out of harbour. That is a given. Their job is to guide ships in and out of the harbour safely. Even a naval ship like ours has to have a pilot on board. There's also normally at least one tug tied up to this ship, if not more because of it's size, to try and guide it out safely. They would have a computerized planned route to go under the bridge at the right place and the right time (tides).

I know this is a big ass ship and not something that turns or stops on a dime.

There's other options that could have happened to try and stop the ship or at least slow it down. The crew could have dropped the anchors (again, a ship this size would have more than one anchor) IF there was enough time to do so. That's a big IF.

I've sailed in and out of Baltimore before, and this is just mind blowing how this happened. I've been the helmsman (in the Navy, we dont use autopilot, we ALWAYS have someone steering the ship based on the Officer on the Bridge, usually the CO, coming in and out of harbours) on CPFs coming in and out of harbour so many times I cant count when I was at a lower rank. I feel bad for whoever was on the helm.

Edit - just hearing that there was a power outage on the ship minutes before impact. That would kill all hydraulics and steerage. Depending on the wind, I could see how this ship got veered into the bridge.

[2014olympicgold]

I was going to say, just the dimensions of the boat and the bridge look like it's not a bridge that large boats go under. Losing power and drifting into the bridge makes sense.

Hope they find the missing people.

[Axeman33]

I was going to say, just the dimensions of the boat and the bridge look like it's not a bridge that large boats go under. Losing power and drifting into the bridge makes sense.

Hope they find the missing people.

You cannot enter or exit Baltimore Harbour without going under that bridge. Ships that size can only enter and leave the harbour at certain times based on the tide times and the clearance so they need a lower tide for clearance.

[Eskimo Brother]

As a structural engineer this hit hard when I saw the video at 4am (kid woke us up and I went on my phone after to make baseball adds). Going to be a big discussion point in my office today. It was mind boggling to watch the failure methods and how quickly it collapsed, but that's just how important the failure/support methods are on a structure like this.

Crazy unlucky set of circumstances, but as Axe said, at least it was overnight to minimize the impact on users. Sounds like a construction crew was on the bridge too at the time.

Definitely going to make me think twice about driving over the Burlington Bay skyway again anytime soon...

[2014olympicgold]

As a structural engineer this hit hard when I saw the video at 4am (kid woke us up and I went on my phone after to make baseball adds). Going to be a big discussion point in my office today. It was mind boggling to watch the failure methods and how quickly it collapsed, but that's just how important the failure/support methods are on a structure like this.

Crazy unlucky set of circumstances, but as Axe said, at least it was overnight to minimize the impact on users. Sounds like a construction crew was on the bridge too at the time.

Definitely going to make me think twice about driving over the Burlington Bay skyway again anytime soon...

It was hit by a dump truck years ago where the driver was drunk and had the bin in the "dump" position and it hit the structure. It caused a lot of damage. I was actually like 100yrds from it going home from work lol.

You cannot enter or exit Baltimore Harbour without going under that bridge. Ships that size can only enter and leave the harbour at certain times based on the tide times and the clearance so they need a lower tide for clearance.

Ah true, the tide.

[Eskimo Brother]

It was hit by a dump truck years ago where the driver was drunk and had the bin in the "dump" position and it hit the structure. It caused a lot of damage. I was actually like 100yrds from it going home from work lol.

I remember that. I now work with some of the guys that had to go out to inspect analyze that aftermath.

[hockeyrobot]

How does the power go out on a ship that size...?

[Axeman33]

How does the power go out on a ship that size...?

Let me do my best to explain.

Most ships are powered by diesel generators at sea (they would be hooked up for shore power while alongside so the DGs are not running). I cant speak specifically to this ship, but my guess is it's no different. Those DGs will feed into switchboards, much like your power breaker panel in your home which feed power to anything and everything on the ship, including steerage. There's always at least two switchboards, one forward and one aft for redundancy. Sometimes the generators will trip but there's backup generators that are supposed to automatically kick in. Sometimes switchboards go down but not as often as DGs tripping. One one switchboard goes down, there's supposed to be certain circuits that would be switched to the other switchboard to keep them running.

If you watch a closeup of the video of this ship like I have this morning, you can see the power go out on the upper decks, then kicks back in again, goes out again and then they made contact with the bridge so it looks like the backup generator that ran the upper deck lights kicked in but it tripped as well. I cant say how many circuits went out during this blackout, but it would appear steerage was affected.

On a Canadian Patrol Frigate (CPF) we have four DGs and two switchboards. Depending on the load required, we could be running as little as one and as many as all four. Rare we are ever on one DG, especially at sea because, again, the entire ship is running off those DGs. I cannot imagine a scenario where the entire ship would go black at sea but it's not entirely out of the question either. It's actually happened to a ship I was on a few years ago after we left Reyjkavic. Not a fun experience. Water in our fuel caused that issue. We were black at sea for over 8 hours until we could physically hand transfer fuel from one tank to another.

[Belexus75]

As a structural engineer this hit hard when I saw the video at 4am (kid woke us up and I went on my phone after to make baseball adds). Going to be a big discussion point in my office today. It was mind boggling to watch the failure methods and how quickly it collapsed, but that's just how important the failure/support methods are on a structure like this.

Crazy unlucky set of circumstances, but as Axe said, at least it was overnight to minimize the impact on users. Sounds like a construction crew was on the bridge too at the time.

Definitely going to make me think twice about driving over the Burlington Bay skyway again anytime soon...

in all fairness it does not matter how you design anything when force of freight ship hits it...nothing will stand...

i know you live in Toronto, mind me asking where you work? Im in similar field. Im a building envelope consultant.

[hockeyrobot]

Let me do my best to explain.

Most ships are powered by diesel generators at sea (they would be hooked up for shore power while alongside so the DGs are not running). I cant speak specifically to this ship, but my guess is it's no different. Those DGs will feed into switchboards, much like your power breaker panel in your home which feed power to anything and everything on the ship, including steerage. There's always at least two switchboards, one forward and one aft for redundancy. Sometimes the generators will trip but there's backup generators that are supposed to automatically kick in. Sometimes switchboards go down but not as often as DGs tripping. One one switchboard goes down, there's supposed to be certain circuits that would be switched to the other switchboard to keep them running.

If you watch a closeup of the video of this ship like I have this morning, you can see the power go out on the upper decks, then kicks back in again, goes out again and then they made contact with the bridge so it looks like the backup generator that ran the upper deck lights kicked in but it tripped as well. I cant say how many circuits went out during this blackout, but it would appear steerage was affected.

On a Canadian Patrol Frigate (CPF) we have four DGs and two switchboards. Depending on the load required, we could be running as little as one and as many as all four. Rare we are ever on one DG, especially at sea because, again, the entire ship is running off those DGs. I cannot imagine a scenario where the entire ship would go black at sea but it's not entirely out of the question either. It's actually happened to a ship I was on a few years ago after we left Reyjkavic. Not a fun experience. Water in our fuel caused that issue. We were black at sea for over 8 hours until we could physically hand transfer fuel from one tank to another.

Absolutely wild. And tragic.

[PenguinHunter]

that went down a lot faster than I would have expected.

[Belexus75]

that went down a lot faster than I would have expected.

the force in that ship is unbelievable....i know it looks like Lego bricks meeting a baseball bat...but its basically same ratio of force to resistance.

[Godin]

Let me do my best to explain.

Most ships are powered by diesel generators at sea (they would be hooked up for shore power while alongside so the DGs are not running). I cant speak specifically to this ship, but my guess is it's no different. Those DGs will feed into switchboards, much like your power breaker panel in your home which feed power to anything and everything on the ship, including steerage. There's always at least two switchboards, one forward and one aft for redundancy. Sometimes the generators will trip but there's backup generators that are supposed to automatically kick in. Sometimes switchboards go down but not as often as DGs tripping. One one switchboard goes down, there's supposed to be certain circuits that would be switched to the other switchboard to keep them running.

If you watch a closeup of the video of this ship like I have this morning, you can see the power go out on the upper decks, then kicks back in again, goes out again and then they made contact with the bridge so it looks like the backup generator that ran the upper deck lights kicked in but it tripped as well. I cant say how many circuits went out during this blackout, but it would appear steerage was affected.

On a Canadian Patrol Frigate (CPF) we have four DGs and two switchboards. Depending on the load required, we could be running as little as one and as many as all four. Rare we are ever on one DG, especially at sea because, again, the entire ship is running off those DGs. I cannot imagine a scenario where the entire ship would go black at sea but it's not entirely out of the question either. It's actually happened to a ship I was on a few years ago after we left Reyjkavic. Not a fun experience. Water in our fuel caused that issue. We were black at sea for over 8 hours until we could physically hand transfer fuel from one tank to another.

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