Bridge collapse in Baltimore

[Chris5156]

News reports this morning that a 1.6 mile long bridge in Baltimore has collapsed after being hit by a cargo ship. Updates here. The video of the event is extremely dramatic - the structure is enormous and it folds and drops into the water in the space of a few seconds.

It happened at about 01.30 local time so traffic must have been light, but it's hard to escape the fact that there must be significant casualties.

It was the Francis Scott Key Bridge, which is here. It carries I-695 over a very wide river estuary.

[freebrickproductions]

Looking at the video, it appears there definitely were at least a few vehicles on the bridge, I wouldn't be too surprised if a high death toll is the result of this, even despite it being early in the morning. Per the Associated Press, authorities are attempting to rescue "at least seven people". Definitely prayin' for those affected.

I-895 and I-95 are the next two river crossings in that area, so no doubt traffic on that side of Baltimore will be snarled for a while until the bridge is able to be replaced.

[DavidBrown]

The video of the collapse is probably the most, for lack of a better word given the circumstances, spectacular videos of such an event I've ever seen. This is pure speculation on my part based on my own observations, but looking at the traffic on the bridge at the time, I can see construction vehicles, I can see plenty of flashing orange beacons, but I cannot see any moving traffic. I'm really hoping that means the bridge was closed to general traffic at the time and that, again without wishing to downplay the seriousness of the incident, only construction workers were on the bridge at the time. I think that's why authorities are already giving numbers of "up to" 20 people in the water, of course what isn't clear at the moment is whether that's workers on the bridge, crew of the ship, or both (EDIT - all ship crew are reportedly safe and accounted for).

In any case, a horrifying incident and fingers very much crossed the casualty/death toll isn't as severe as it might look at the moment.

[Helvellyn]

Just a blessing (although I hesitate to use the word in these sorts of circumstances) that it happened in the middle of the night and not at rush hour.

[Bryn666]

It shouldn't have happened at all of course as the USA has had 44 years to learn from the identical disaster at the Sunshine Skyway in Florida, and the Big Bayou Canot disaster in Alabama (which was a railway but same cause - wayward vessel striking an unprotected bridge).

Questions really need to be asked about the safety of American bridges, this clearly looks like an accident but in these paranoid of terrorism times you would think critical infrastructure would be given a little more thought as to resilience from ramming attacks and the like.

[Mark Hewitt]

It shouldn't have happened at all of course as the USA has had 44 years to learn from the identical disaster at the Sunshine Skyway in Florida, and the Big Bayou Canot disaster in Alabama (which was a railway but same cause - wayward vessel striking an unprotected bridge).

Questions really need to be asked about the safety of American bridges, this clearly looks like an accident but in these paranoid of terrorism times you would think critical infrastructure would be given a little more thought as to resilience from ramming attacks and the like.

Are American bridges partiuclarly vulnerable to this? Compared to eg the Queensferry Crossing or the Severn Bridges?

[Conekicker]

It shouldn't have happened at all of course as the USA has had 44 years to learn from the identical disaster at the Sunshine Skyway in Florida, and the Big Bayou Canot disaster in Alabama (which was a railway but same cause - wayward vessel striking an unprotected bridge).

Questions really need to be asked about the safety of American bridges, this clearly looks like an accident but in these paranoid of terrorism times you would think critical infrastructure would be given a little more thought as to resilience from ramming attacks and the like.

Are American bridges partiuclarly vulnerable to this? Compared to eg the Queensferry Crossing or the Severn Bridges?

I think US bridges are built to a lighter standard than UK bridges. For example, I find it hard to believe what they used for parapets on the now ex-bridge:
https://www.google.com/maps/@39.2194734 ... ?entry=ttu

[Helvellyn]

Is it realistic to expect any bridge to survive being struck by a container ship? Even at low speeds the kinetic energy in those things must be immense.

[RichardA35]

Is it realistic to expect any bridge to survive being struck by a container ship? Even at low speeds the kinetic energy in those things must be immense.

Interesting to note the lack of fendering or caisson to deflect any ship away from the areas where the full height clearance is not available, i.e. the immediate area adjacent to the piers.
From what I have seen, UK practice would normally have included such deflection so the vessel was directed away so the critical member could not have been struck.

[Bryn666]

Is it realistic to expect any bridge to survive being struck by a container ship? Even at low speeds the kinetic energy in those things must be immense.

Correct, which is why vulnerable piers in waterways like this are meant to have guarding in the form of energy absorbing islands or similar - a practice introduced but not rolled out after the Sunshine Skyway disaster.

It's not just ships that are a threat, a bridge on the New York Thruway collapsed because of the river itself washing away foundations because the protection from scour simply did not exist.

[ChrisH]

This bridge is on the access route to the Port of Baltimore so it must have hundreds of heavy vessels transiting it every week. Needless to say, the closure of the Port for the foreseeable future will also be pretty impactful on the local economy and the logistics industry.

[Mark Hewitt]

https://x.com/ChaudharyParvez/status/17 ... 09075?s=20

Video showing how the ship lost power twice on the way to hitting the support.

[FosseWay]

Is it realistic to expect any bridge to survive being struck by a container ship? Even at low speeds the kinetic energy in those things must be immense.

Correct, which is why vulnerable piers in waterways like this are meant to have guarding in the form of energy absorbing islands or similar - a practice introduced but not rolled out after the Sunshine Skyway disaster.

Something that occurred to me is that similar bridges exist in war zones, most obviously the Kerch Strait. If all that was needed to bring it down was to aim a large ship at it, I'd imagine someone would have done just that deliberately in the last few years, yet they haven't. Which suggests the bridge supports there are protected against this, whether deliberate attack or otherwise. It does seem strange that similar protection isn't automatic anywhere where large ships are manoeuvring.

[Helvellyn]

Is it realistic to expect any bridge to survive being struck by a container ship? Even at low speeds the kinetic energy in those things must be immense.

Correct, which is why vulnerable piers in waterways like this are meant to have guarding in the form of energy absorbing islands or similar - a practice introduced but not rolled out after the Sunshine Skyway disaster.

Something that occurred to me is that similar bridges exist in war zones, most obviously the Kerch Strait. If all that was needed to bring it down was to aim a large ship at it, I'd imagine someone would have done just that deliberately in the last few years, yet they haven't. Which suggests the bridge supports there are protected against this, whether deliberate attack or otherwise. It does seem strange that similar protection isn't automatic anywhere where large ships are manoeuvring.

I'd imagine that that bridge is rather carefully monitored, with lots of anti-ship missiles in the vicinity.

[FosseWay]

I'd imagine that that bridge is rather carefully monitored, with lots of anti-ship missiles in the vicinity.

True, but what you said about kinetic energy earlier still applies. There must be a point where even if you fire a missile at a huge ship that's under way, it will still hit whatever it's pointing at before eventually running out of momentum.

[Helvellyn]

I'd imagine that that bridge is rather carefully monitored, with lots of anti-ship missiles in the vicinity.

True, but what you said about kinetic energy earlier still applies. There must be a point where even if you fire a missile at a huge ship that's under way, it will still hit whatever it's pointing at before eventually running out of momentum.

They'll doubtless attacking any ship they're not sure about long before it gets anywhere near to the bridge. Missiles have very long ranges.

[Conekicker]

Correct, which is why vulnerable piers in waterways like this are meant to have guarding in the form of energy absorbing islands or similar - a practice introduced but not rolled out after the Sunshine Skyway disaster.

Something that occurred to me is that similar bridges exist in war zones, most obviously the Kerch Strait. If all that was needed to bring it down was to aim a large ship at it, I'd imagine someone would have done just that deliberately in the last few years, yet they haven't. Which suggests the bridge supports there are protected against this, whether deliberate attack or otherwise. It does seem strange that similar protection isn't automatic anywhere where large ships are manoeuvring.

I'd imagine that that bridge is rather carefully monitored, with lots of anti-ship missiles in the vicinity.

Perhaps, but an anti-ship missile would not be able to sink a large ship before it hit the bridge, especially if it was thought to be simply passing under the bridge in the shipping channel. A last minute turn of the ship's wheel 500m-1km before the bridge and a large vessel would be practically impossible to stop. I guess you'd need some mines to rip out the bottom of the ship and even then it might not guarantee stopping it in time. Plus you'd risk blocking the shipping channel.

[Glen]

Is it realistic to expect any bridge to survive being struck by a container ship? Even at low speeds the kinetic energy in those things must be immense.

If the piers themselves wouldn't withstand a collision they should have sufficient protection, especially the ones either side of a shipping channel, this bridge appeared to be lacking any significant protection.



Compare that with the old and new Sunshine Skyway bridges.

Something that occurred to me is that similar bridges exist in war zones, most obviously the Kerch Strait. If all that was needed to bring it down was to aim a large ship at it, I'd imagine someone would have done just that deliberately in the last few years, yet they haven't. Which suggests the bridge supports there are protected against this, whether deliberate attack or otherwise. It does seem strange that similar protection isn't automatic anywhere where large ships are manoeuvring.

The Crimean Bridge does have structural dolphins protecting the piers on the main span, the piers on the viaducts are more vulnerable, but would less likely to be damaged in an accidental collision and a collision with them would be less likely to bring down the entire bridge.

[Mark Hewitt]

https://x.com/ChaudharyParvez/status/17 ... 09075?s=20

Video showing how the ship lost power twice on the way to hitting the support.

It is also clear from that video the bridge was not closed to traffic, however the final vehicle seems to make it across the span mere seconds before the collapse, the maintenance vehicles still fell victim of course.

[bothar]

The Russians have sunk old ships and the like to prevent an attack on the Kerch bridge
https://www.politico.eu/article/russia- ... s-says-uk/

In the Baltimore case, it seems that the ship's engines cut out and the ship may well have drifted into the bridge.
Presumably, one approach here would be to require ships to pass under the bridge under tug power, but the main problem is that once the ship has speed then you cannot stop it.