Youtube tracking analysis from a knowledgeable mariner.
He says that at about 1:24 AM the ship loses power (from video feed) while traveling 8.5 knots.
at 1:25.30 power is restored.
at 12:25.59 the ship shows smoke. The ship has already drifted in the channel. It is believed that at this time the ship applied full reverse power as evidenced by the black smoke. (My analysis: the ship drifted but hasn't turned in the channel, more of a translation)
By 1:26.45 the ship has obviously turned in the channel pointing at the pier. Full reverse would cause prop walk to change heading angle;
1:28.52 impact at 7.6 Knots. Camera says 1:28.52, AIS reports the ship still moving at 1:29:35
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 brakes realizing misalignment. Obviously 2-3 minutes is not enough to stop 100,000 tons at 8.5 kts, since it only got to 7.5 kts before crashing. Power loss may have caused total rudder loss.
Similar to a car that hits ice, wheels have arbitrary alignment when they reengage road, when power starts being delivered again, car swerves towards concrete barrier even with brakes. Driver with limited crash experience is mostly just panicking and stomping.
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?
Edit: Also, economic disaster for Baltimore.
> (Wiki) The Port of Baltimore generates $3 billion in annual wages and salary, as well as supporting 14,630 direct jobs and 108,000 jobs connected to port work. In 2014, the port generated more than $300 million in taxes. 1st in automobiles, light trucks, farm and construction machinery, imported forest products, aluminum, and sugar. 2nd in coal exports.
3,600 commercial trucks / day. Hazardous material transport has a 30 mile detour. Baltimore had $350 million of insurance. However, Brent Spence Bridge is noted for cost comparison at $3.6 billion and 1/5 the length.
On ships like this the propulsion is separate from the steering. There is a separate rudder that is close to, but not attached to the prop and propshaft. The propshaft is fixed. The rudder doesn't just "restart in a random position" it would remain in the previous position unless there was a physical piece that broke in the rudder gear.
The fact that ship was able to reverse hard ( as evidenced by the slowdown), indicates to me that the prop was most likely still attached to the propshaft and hadn't flown off to mangle the rudder.
We still don't know exactly what happened on board, but it is interesting to work through possible scenarios.
Pilots certainly have experience with ship handling of 100,000 ton ships, that's their job. Pilots coordinate the moves of multiple tugs to assist with docking regularly.
I'm not sure what configuration of props a ship like this has, but in my experience with a 40ft sailboat with a single propeller you have absolutely no rudder authority while reversing. I've read that some large ships also are direct drive--there's no transmission between the engine and the propeller, so "reversing" (if it's even possible) entails shutting down the engine and restarting it in reverse. This can be done with a two stroke engine. And yes, 8.5kt is not slow when you're displacing 100k tons, no correction will happen quickly.
> 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.
This seems like a system architecture error. Boats do weird shit sometimes and so bridges need to be deigned to not fall down when a boat crashes into them. Requiring a huge boat to be steered to meter resolution when clearly that's not always going to happen is top shelf stupidity. Up there with backup generators in the basement below the water table.
> 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 think you are missing the point.
Clearly I am speculating, but I don't think any more experience would have helped in this event.
Why ? I think what happened today was almost entirely down to not being able to fight the basic Laws of Physics.
Its a well known fact that enormous ships take an equally enormous amount of time and distance to reflect the actions of the captain. You make an input and you see the result a bunch of time and distance later.
Time and distance were, sadly, not on the captain's side today. Physics took care of the rest.
I've driven a number of vessels, ranging from a 17' dinghy to a nuclear aircraft carrier and have a number of friends who have been involved in accidents one way or another. I have personally not had the conn during disaster, but have been an engineering officer and a legal officer responding to them, on my ship. To be honest, steering a ship under most conditions is not hard. The anxiety-provoking issues are 1) poor bridge team management (aka toxic leadership) and 2) engineering disasters, which this appears to be.
This
> Similar to a car that hits ice, wheels have arbitrary alignment when they reengage road, when power starts being delivered again, car swerves towards concrete barrier even with brakes. Driver with limited crash experience is mostly just panicking and stomping.
is almost certainly not the case on a large ship. The rudder is rotated hydraulically. Loss of power simply causes the rudder to stop moving, it's effectively "stuck". Some ships have manual override using a massive wrench, but it takes hours to move the rudder meaningfully in that situation.
As for this:
> 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?
Probably way more than you think. This is a significant reason why they seem so calm when they show up on the bridge. They just hopped from a relatively tiny pilot boat or tug onto a massive ship, possibly with significant sea state. This can be some Indiana Jones level crazy.
Pilots are very seasoned mariners who have seen multiple losses of power, and pretty much everything.
Now, back to point 1: bridge team. I have seen a captain the crew trusts execute flawless maneuvers even in exigent circumstances. I have seen a captain the same crew doesn't trust fail repeatedly at everyday things.
We don't have the whole story yet. What happened on the bridge? What happened in the plant? Why did power drop? Did they flood an online generator with diesel oil? I ask because I've seen that happen. Did they blow an exhaust manifold? Seen that. Did they trip the plant by getting preparatory checklist work backward? Seen that. Did they go all back full immediately? Possible that they couldn't ring the order if they dropped power. Was there panic on the bridge (bad sign) or was there grim fortitude to process checklists that would never help (better sign). In any case, no doubt the captain is done. Probably happy to never drive a ship again after that, tbh.
Admittedly very naive question: would they have an anchor? Would it be long enough to hit the channel bed? Could dropping it have helped prevent, or at least slow down, the ship?
Or even if so was it just too late when it all went down and it wouldn’t have made a meaningful difference?
I hope the next POTUS makes good on Biden's promises because Baltimore and Maryland will need federal assistance since they can't afford such a burden.
And I assume there will lawsuits to recover costs as this caused economic damage and risk to life (8 people unaccounted for at current time).
The video is surreal, it looks like it barely bumps the bridge and 2 seconds later the entire thing is gone. I don't know what I was expecting, the bridge just looked extremely fragile, makes me wonder what other bridges are at risk of an event like this.
It's not the impact, it's the fact that it just keeps pushing. Movies commonly use slow motion and time extension via editing for destruction scenes because (as we've just seen) real time doesn't always look impressive to the untrained eye.
Also, there's a lot of mass concentrated in that ship. It's the equivalent of hitting a window with a sledgehammer. Small recreational vessels could probably crash into those pylons all day long.
That ship had a 10,000 TEU capacity and was actually hauling a little under 5,000 TEUs. An empty container weighs a little over 5,000lbs, and a full one can be up to 67,000lbs.
If you do the math, you find that it’s just an astronomical amount of momentum, and there’s no effective defense for a bridge that needs support in more than 30 or so feet of water.
It's somewhat counterintuitive how much energy can be in something moving so slowly. I say somewhat, because when you're up close it's much more obvious, but you're right that on a video it doesn't look like much.
When you play about with game engines long enough, you start to realise that momentum is the key metric to track rather than speed. Especially in water magnitude can be very deceiving but to give some quick math, this vessel had a momentum at impact of about 154,000,000kg⋅m/s. For a car to have equivalent momentum it'd have hit the bridge at 156,580 mph. Humans are just less adept at appreciating mass vs velocity.
> I don't know what I was expecting, the bridge just looked extremely fragile, makes me wonder what other bridges are at risk of an event like this.
The bridge style in question
> Conversely, continuous truss bridges rely on rigid truss connections throughout the structure for stability. Severing a continuous truss mid-span endangers the structure. However, continuous truss bridges do not experience the tipping forces that a cantilever bridge must resist because the main span of a continuous truss bridge is supported at both ends.
I remember when I was a kid, I left a bus, and the bus started moving, and I, not being intimidated by the bus moving very slowly (somewhere between 5 and 10 km/h), didn't move a safe distance away from the bus. I think the bus, due to the nature of its maneuverability, had its tail moving not in parallel to me but slightly towards me - so when it has "touched" (hit?) me, even though I thought it was just sliding in parallel, the force was so strong I made a full 360° turn - and I was a tall and chubby boy.
I ended up with no injury, not even a bruise as far as I can remember (who would count bruises as a kid), but definitely with an intuition to respect mass.
> I don't know what I was expecting, the bridge just looked extremely fragile
The strongest man in the world probably seems pretty solid. Put him at the bottom of a 3 degree grade and release the brakes on a full tractor trailer and he'll seem fragile too.
Probably most of them. A structure like that not designed to bear vertical loads, not lateral ones, other than high winds.
The knee is like this too. It lets you stand, run and jump just fine, but you can knock down an opponent with a relatively mild lateral impact to the knee.
Much more of the bridge collapsed than you might think, though, far from the impact.
Bridges are design to withstand a very predictable type and direction of force. It can withstand the lateral wind, but imagine how much force a fully loaded cargo ship can put into it. Once one segment gone the rest is history, because makes the who construction imbalanced.
I'm once again impressed that subject matter experts are out there on every topic, and they are often capable of quickly and accurately disseminating information about an event far better than the local news.
How common are power outages on ships? I get that the captain might not have responded to it correctly but that seems like a thing that shouldn't happen, at least in my completely uneducated opinion.
It is quite common and vessels often have outages that leave them Not Under Command. Usually they are safely at sea when this happens and they can drift for hours without causing problems. But of course there's always a possibility of it happening at exactly the wrong moment.
The reasons for this are the usual: lack of redundancy, lack of maintenance, overworked and understaffed crews, etc. etc. The book lays out how ships are pretty much designed to be floating disasters and the Class societies (essentially privatized regulators) are in the pockets of the builders, and they are so captured that they make rules that make it difficult to make safe vessels.
For instance, he was trying to design multi-screw vessels but the rules now assume single-screwed ships and it can be impossible to design in additional shaft alleys and still conform.
It shouldn't happen. There will be investigations. I think that having a properly operating ship is the captain's responsibility.
But the ship's pilot [1] (not captain) should know exactly how the boat will handle and the exact course of action. Pilots are extremely well paid ($200-$400k) and the tests are very stringent. Friends have told me that the Narraganset Bay pilot test involves drawing every shipping navigation bouy on a map by hand to within ~200 yards from memory alone, compass, ruler and scaled map provided.
I was curious about power outages as well, and why tugboats aren't required for all container ships that navigate under bridges. I'm not arguing that tugboats MUST be mandated; just wondering about the cost/benefit analysis. This claims that power outages are more common now (but doesn't cite sources/stats) in areas (specifically California) where diesel fuel is required, rather than bunker fuel: https://baykeeper.org/news/column/tugs-test-towing-giant-shi... It also makes it clear that relying on tugboats to be on standby and "swoop in to the rescue" is seriously wishful thinking where bridge safety is concerned. This article from 2019 is about a power failure due to an Oil Mist Detector that didn't have a "harbour mode" option of keeping the engine running at reduced RPM so you can still maneuver. It also shows the link between engine failure and a need for tugboats under "lessons learned":
"– Although it is tempting to free harbour tugs as quickly as possible, in the restricted waters of a small port their assistance can be invaluable should something go wrong."
On the other hand, what safety or economic issues do tugboats cause? It will probably become a topic of discussion or investigation at least.
The American courts should hit Maersk really really hard financially and get them to foot the bill for all losses of the bridge collapse. Shipping companies should not be driving vessels of these huge tonnages with such poor levels of redundancy and poor levels of manning.
It is insane for a 100,000 tonne vessel, that takes so long to stop due to its incredible inertia, that can find itself many thousands of miles from land, to rely on one engine, one gearbox, one shaft and one rudder; without sufficient secondary and tertiary back-up systems. Why was there no battery back-up, or motor on the shaft? Surely the bow thrusters should have a battery back-up to stop such a lurch to starboard.
How can all of the generation and all electrical busbars fail at once? Even if the fuel was bad, surely the generators should draw on separate fuel tanks. For such a large and relatively modern ship to suffer a total power failure is complete corporate incompetence.
If, as some allege, the refrigeration containers were causing problems, and total power outages occurring before sailing, the vessel should not have sailed, certainly at night. If this is the case, The Master needs locking up. But, poor man has to take the blame, because he is cheaper than a Danish Master and his Singaporean employer (if he is employed and not a contractor) also operating in a cheaper flag state than Denmark. The Singaporean Company also needs hitting hard if the culture was the cause of the Captain sailing after such alleged pre-sailing power outages.
Maersk outsource to reduce personnel and running costs. They use the cheapest crews, cheapest ships and need hitting very very very hard. We might then stop this culture of wealthy shipping companies using every method possible to avoid complying with IMO and more rigorous Nation State standards, operating in the shadows and ducking accountability and responsibility.
Does that mean this was effectively captain error? Like in response to a power outage the decision was made to try to reverse and rather than arrest forward momentum it just pushed their forward vector into the piling?
I would tend to think so. The pilot should have anticipated prop walk and known that the ship had no chance of stopping before the bridge.
I’m trying to find a color coded current map. Wind too. I wouldn’t expect wind or current to cause the pronounced heading change that is visible. The drift seems possible.
Note: I’m an experienced dinghy/keelboat sailor, but lack virtually any experience driving boats under power, much less commercial vessels
That timeline implies that there was only four minutes to respond. Is that correct? Where was the ship going? Does it travel under this bridge on its own power rather than a tug boat?
What I am wondering is: why couldn't the bridge have been blocked off preventing casualties? It seems like more than just the boat and operators' failing if there's no time or secondary precautions if such failures occur.
I wonder if it makes sense to protect bridges with pylons like they have in front of buildings to stop cars and trucks.
It was blocked off the shortly after the ship pilots sent their mayday signal and declared an emergency, giving the traffic that was on the bridge time to make it through.
Most (all?) of the people on the bridge were contractors repairing potholes.
> I wonder if it makes sense to protect bridges with pylons like they have in front of buildings to stop cars and trucks.
They're called "dolphins" and some bridges do have them.
It's fairly horrifying how fast the bridge collapsed after the moment of impact on the pylon. The whole span seemed to fall in totality almost at once. If anyone was on that bridge at the moment of impact, they were in the water a couple of seconds later.
As an inland armchair-captain, I want to admonish that tugboats should probably always be stationed around bridges to intercept such off-course mariners.
Apparently (this is just via someone on Reddit who supposedly heard/read it somewhere) the ship mayday'd on losing power hoping the bridge could be cleared.
But why not (or did it?) also just blast its horn repeatedly, drawing attention so people on or near the bridge would notice it and realise something was wrong and perhaps even where it was headed?
I'm sure it's not allowed generally and not the protocol and whatever ... But it does seem like a common sense & do whatever you can sort of situation to me?
There are specific horn signals (one prolonged, or seven-short-one-prolonged, are what I'd guess would be appropriate here), and COLREGS do explicitly say that you can use whatever you need to get attention in an emergency as long as it's not confusable with some official signal. But as other commenters have noted it wouldn't have been specific enough to get the workers etc to clear the bridge before the impact.
> But why not (or did it?) also just blast its horn repeatedly,
It's hard for people on the bridge to understand what that means. The more it blasts the horn, the more likely people to turn around, stop and maybe get their phones out to take a video what strange thing this ship is doing. By the time they realize the impact is imminent, it's too late, unless they take a helicopter ride.
Because horn blasts are very specifically meant to communicate something to other ships. Once you're in "just blast it" mode you're seconds from disaster. I recognize the nobility of your suggestion, but I don't think it could have saved more than couple lives at most, probably none.
Blasting the horn repeatedly is not a standard signal, but there are standard signals which might apply to a situation like this, for example "vessel not under command", "collision imminent", "vessel reversing", etc.
How much of this is falls on the protocols of the shipping company? I.e. the same shipping companies that gouged the planet during covid - did they strip away safety protocols in order for profits/expediency?
Is this similar to Boeing for the shipping world? I realize it is early to come to any conclusions.
The question of this being a rare one off vs container companies deprioritizing safety protocols is what I am interested. The power failures make me go down this logic of thought.
Boeing makes and sells planes, they don't fly people.
Maersk/ZIM rent container ships from another company who makes them and drive them around.
These are completely different companies. A more correct comparison would be something like Jetblue or American Airlines.
But I seriously doubt there is the result of some kind of profit hungry CEO. However I cannot with 100% say it's not until we find more details. But I feel confident enough to avoid the tin foil hat.
Not that it matters to anyone else, but having driven across that bridge dozens of times with my kids, this is just shocking. It’s one of the main corridors in the area. Thank god it happened in the middle of the night, though that’ll be no consolation to the families of those who may have died.
According to current reports, the Maryland Transportation Authority Police responded to the ship’s “mayday” and stopped traffic in the minutes before the catastrophe, but 6 construction workers are still unaccounted for.
There is a semi-truck that enters from the right just before the crash at https://youtu.be/N39w6aQFKSQ?t=299 (4m59s). And some more vehicles that follow after. Doesn't seem like they stopped "all" traffic as is claimed.
Yeah. I was out of town hiking in Wyoming at the time and was told it was the 35E bridge by a passing hiker who relayed the news to me. My mom drove the 35E bridge twice a day. I couldn’t hike out and call home fast enough. I didn’t know anyone who was on the bridge when it fell but I do know many who missed being on it by minutes. Scary stuff.
I remember standing not far from edge of that shortly after it happened (https://www.flickr.com/groups/35w-bridge-disaster/), and still get a little panicky when I'm in slow traffic on a bridge. This event will affect the city, the port, and its people for a long time.
That was my exact thought.
Thankfully, I woke up to messages that my family members were safe and sound.
I hope they find everyone but at this point it seems unlikely.
Growing up my grandmothers house was on the watet across the Bay from Baltimore. This bridge was literally in the backdrop of my childhood. Scary stuff.
Local to the area. This was devastating news to wake up to. I don't know what's wrong with me but seeing this and knowing there were casualties made me cry.
I worked next door to the church that was shot up in Charleston and felt similarly moved despite not knowing them, never having been inside the building, and not having even been a Christian at the time.
It is a bit strange at some level - not having any true connection beyond proximity but you should probably worry if you _don’t_ at least feel a little something.
Nothing wrong with crying. I cry sometimes. Heck, if I spend too much time thinking about the 343 firefighters who died on 9/11, it will still bring a tear to my eye even after all these years. It's just part of the human condition. Cherish it.
Do you happen to know how they stopped traffic? Are there warning lights at the ends of the bridge? I have seen bridges of this sort but they are fairly rare.
I'm wondering if that's how they stopped almost all of the traffic. Flip a switch, most people stop, a couple of assholes blow through the caution and FAFO.
I don't think that's quite right. People in Dundalk will suffer a fair bit, as will folks in Glen Burnie and Annapolis, but most people are going from DC to Delaware, and go north rather than over the Key bridge.
I think this is most harmful for commuters.
Blocking the Baltimore harbor is brutal although I suspect the passage will be cleared as quickly as possible.
I think 30-35k cars a day cross that bridge. Being local to the area, is is going to make traffic in the entire metro area much worse, and it is already awful.
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 not happening.
Does anyone know if modern construction standards would require more stability after a ship collision, or is this still how we build bridges?
At least in the links with the video now you can see that the container ship directly hits one of the two main (and in the central area only) pillars completely collapsing it.
No matter(1) the engineering there is no pretty much way to not lose the whole large middle area and left area leading to the destroyed pillar in that situation.
Such a collapse crates so much force (tension vibrations etc.) so that the collapse of the section right of the right pillar is not unreasonable.
The only question is if the impact should have made the pillar collapse.
But a loaded container ship is ... absurdly massive I mean they are like multiple high raise building (but not sky scrapers) standing squished together side by side. So the force it can apply is huge and if cargo moving in it there will be force applied to whatever it crashes into even after the initial impact.
And looking at the waves caused by impact with the base it was at least 8m high I think (depending on the container ship). So that wasn't a "slow moving" impact. And even slow moving impacts with container ships can tear apart a solid jetty.
So while the US has issues with infrastructure maintenance idk. if anything but building a many pillar bridge would have made any difference. And building a many pillar bridge might not be very viable depending on the under water landscape and water use under the main area.
EDIT: Looking at pictures with daylight where you can try to estimate the high of the ship using containers I would say the waves where handwavingly 4 containers high so ~9.5m and it also looks like the ship might have embedded half of the pillars fundament into/under itself (but it's a bit hard to tell to the angle of the picture). I think if that's the case probably the huge majority of bridge pillars of past and presence would have collapsed.
The MV Dali (IMO#9697428) is a little over 95000 GT, or ballpark-ish probably around 114000 tons loaded (and it seems to have been loaded, which would make sense on departure). If it was going even 5kn (2.6 m/s) that'd be about 300 million newton-seconds, or about 3.3 times the momentum of a large jumbo jet like a 747 shortly at cruising speed (around 560 mph). It'd still have the same momentum as said jet if it was going just 1.5kn. The ship of course is enormously more stoutly built and the force is going to be transmitted far more directly into whatever it hits vs into explosions driving mass elsewhere.
I've read that both on water and in space for that matter enormously massive objects moving very slowly messes with human perception and "common sense", it "feels like" something moving along smoothly and slowly should be stoppable or come to a stop. Enormous momentum and forces can be terrifying things.
It certainly does not seem reasonable to design a bridge pillar to withstand a direct impact from a massive cargo ship.
But I guess I thought that maybe there was... typically some kind of earthen buffer around the pillar to prevent such an impact?
That's probably impractical too, I guess.
I guess I just didn't realize ~$1bn bridges were one fluky ship accident away from total collapse at any given time. I think maybe I prefer my previous state of ignorance, to be quite honest....
I mean, yes, everybody is pointing out about the mass of the container ship, but that's actually to the point of the above question and my question. Because the ship's size and weight are obvious. Were ships this size regularly passing by or under this bridge such that this scenario was effectively bound to happen given a ship failure and/or pilot error? That's my question. I'm not familiar with port activities, so it seems weird to have basically no secondary protection for that bridge with container ships of that size operating so close that they can hit it mere minutes after some failure.
Watching this video (https://www.youtube.com/watch?v=qJNRRdha1Xk) shows that the ship was incredibly close to the bridge in the first place, even prior to the supposed failure. It's a bit bewildering to me, with my current knowledge, that this scenario wasn't envisioned prior.
You don't need to build the bridge to an absurd strength, but it may have been insufficiently marked as a navigational hazard. Something like a few well-lit pillars 500 feet upstream in the water would have given the ship plenty of warning to change course, since a vessel travelling at 5 knots takes about a minute to go 500 feet. The total bridge length is on the order of 10,000 feet, so widening the safe area around the pillars to 500 feet would not be a significant impediment to navigation.
Most bridges nowadays (say last century) depend on a careful balance of forces that are transferred through a chain of members in tension and compression.
When any piece in the chain of those forces breaks, the entire structure loses ability to transfer forces and breaks.
This arrangement is what allows us to build these structures in the first place. There is careful calculations of forces and risks and allowance for margin for error and unexpected events. But, unfortunately, in many cases those do not include ramming things with a large container ship...
On a long enough timeline we all get rammed by a container ship.
I would be interested to know some calculations with factors like: expected bridge lifetime, chance of being rammed per year, cost of making supports strong enough plus an extra safety margin to survive maximum ramming force, cost of having major commercial shipping route unusable for an extended period.
It is worth observing that this bridge seems to have 2 pylons and one of them collapsed. The failure seems comprehensible after that - you can see in the video how the balances came apart, there is nothing to hold the left side up so it falls and then remainder of the bridge tried to rotate around the remaining pylon and failed.
Thanks! So why are huge—ass container ships allowed to navigate underneath fragile public bridges with single points of failure? The not unlikely worst case is that the ship is out of control for some reason…
Many homes also incorporate lightweight trusses that can fail in a similar fashion. They pose a unique risk for firefighters, which is why New York went so far as to require warnings be posted outside such structures: https://www.finehomebuilding.com/2015/01/28/new-york-now-req...
Yes, and it looks like it did take out an entire section. So it isn't like the ship just 'nicked' it and bent a few members. An entire support was taken out.
You could try to avoid collisions with barriers, or make the bridge fail differently (only a few spans), or make it tolerant to a single support failing. But you need a pretty beefy steel beam to survive a direct hit by... Uh... 200,000t(??) traveling even at a slow jogging pace. (And then it transfers the energy into the rest of the bridge, which will very much not like it).
I guess we can be happy failure like this is rare, and that the bridge was not busy: reports indicate 13 cars, and about 7 persons still missing. This could be so much worse.
The best way to think about measures is after we know the full chain of events that have lead to this.
Right. I am not really thinking of designing pillars that are impossible to knock over. I am thinking of alternative bridge designs where a higher percentage of the total bridge stays up when one pillar is taken out.
On this bridge, the main section of the bridge is supported by four spaced pillars, making three main spans there. One of the middle two towers was hit, so this should affect two of the three spans. But it took down all three of them. A span that was supported on both sides by intact towers still came down. That is what I find most surprising here.
Why would slumping or buckling but not-quite-collapsing be a functionally better outcome than complete failure? In both cases, the sheer size of the physical changes is going to lead to forces that humans won't survive, so there's no benefit there. In both cases, the bridge is going to have to be completely demolished before rebuilding, so there's no benefit there.
A bridge that could stand the loss of a single support pier without any significant collapse would obviously be preferable -- but that's a big ask. I'm not a structural engineer, but I am aware of scaling laws [1] and it feels to me that those scaling laws are going to mean that increasing the margin of safety by x is going to increase costs by x^n. For a project like this one, where cost was apparently the deciding factor over a tunnel, that matters.
>Why would slumping or buckling but not-quite-collapsing be a functionally better outcome than complete failure?
Well for starters, there's a better chance of less (or ideally no) people forced to get their feet wet and go missing or die from drowning or hypothermia.
I would say the damage is about the same, The ship knocked down a pier and all spans connected to the pier went down. The difference is, on the baltimore bridge is that the spans are a lot longer. But all other spans(the ones nearly out of frame) are still standing.
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."
Check out Brick Immortar (it’s a pun) on YouTube for some in depth videos on past container ship collisions with bridges and how newer bridges are engineered.
There is this often in HN featured article about bridge engineer analysing bridge collapses in film [1]. It’s about suspension bridges though but the takeaway for me was that when they go they go completely.
I like this quote. We have a medieval bridge near to our house (1000 years old perhaps), it's incredibly solidly built, but could you call it well-engineered?
It's a subtle distinction that I don't think many in the digital realm quite grasp either i.e. far too many over-engineered technical solutions for features and products that aren't even desired
Why are you throwing shade at civil structural engineering?
Do all bridges we build need to be able to withstand the force of an entire shipping container bridge hitting it at high speed? What planet should an engineer think that a shipping container has managed to veer off course so badly that they hit a bridge at full speed, fully loaded? That is a sad and significant outlier event.
The Mathews Bridge in Jacksonville was clipped by a container ship a few years back and did not collapse. Despite being almost 75 years old, they fixed it up and it opened back up after a year or two. The difference is that the boat did not hit a pylon.
> 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 not happening.
There are cities with skyscrapers near airports, which depend on the airplanes not hitting the skyscrapers.
One factor that a lot of people in this discussion are missing is that buildings are primarily built to resist vertical forces, because gravity is by far the largest force any building (or bridge) ever experiences.
Having a large force strike perpendicular to gravity is just not something it's designed for at all. All it ever has to handle in the form of force from that direction is wind, and that's absolutely nothing compared to a fully laden container ship hitting it.
I would guess none. No bridge span could survive complete loss of it's supporting abutment. Some bridges are engineered to survive partial loss. For example if the left side goes the right side will hold it up. But from the video the ship looks like it took out the entire supporting structure.
In 2013, a tanker ship hit the Bay Bridge (Oakland <--> SF) but didn't do much damage. In 2007, another tanker (Cosco Busan) hit the same bridge dumping oil into the bay: https://www.youtube.com/watch?v=upfjxfl2nRM. We have a new bridge there now because that one was also damaged in the Loma Prieta earthquake.
When the Golden Gate needs replacement, the Marin NIMBY's that didn't extend BART to the north bay are going to be sad (more likely, their children will be).
Simply bulking up the ground around the piers with loose fill or monolithic concrete would have had the ship run aground; at 9mph (the recorded impact speed) the ship would have slowed to a stop within several yards, and suffered minor damage, maybe would have required being tugged back into clear waters. Running aground puts the majority of impact into a downward force absorbed by the earth. It's hard to build a bridge pier that will withstand 200,000 tons of direct impact, no matter how slowly that's moving.
Ironically, simply bulking up the ground around the piers would have had the ship run aground; at 8 knots the ship would have slowed to a stop within several yards, and suffered minor damage, maybe would have required being tugged back into clear waters. Running aground puts the majority of impact into a downward force absorbed by the earth. It's hard to build a bridge pier that will withstand 200,000 tons of direct impact, no matter how slowly that's moving.
That's what makes sense to me. Ships are designed to minimize drag going through the water. But the friction of the entire hull scraping across the bottom should be MUCH larger and thus able to exert lots more stopping force.
Also, if the ground is sloped, it will act like a ramp, lifting the ship out of the water. The loss of buoyancy means its weight will push downward on the ground below it. An increased normal force means more friction, thus more stopping ability.
This brings back to memory 911 conspiracy theories.
Many revolved around the unlikelihood that a building would collapse the way the towers collapsed just due to knocking out a few floors at the top. But the truth is all these mega structures are quite fragile and can instantly collapse in unintuitive ways.
I don’t drive boats or around water much but I’ve seen “bumpers” on bridge pylons before that make a collision more of a glancing blow and guide the boat to the side. I guess there wasn’t any installed on this bridge? Also, someone on Imgur pointed out that when this bridge was built boats that large weren’t a risk. That may or may not be true but sounds plausible.
Ironically there are power lines running in parallel that have much more substantial protection, here you can see the powerline protection and the tiny bumpers...
Fenders and such. A major problem is this bridge was designed and built in an era where ships were substantially smaller (3000 TEU) than they are today (20000 TEU).
If you watch it in slow motion and how it breaks apart, you won't really find it surprising how things snap and bend considering how big the container ship is compared to the bridge. It makes a lot of sense.
I did hear one expert on the news say that a better, low-tech defense some bridges have is sacrificial piers in front of the actual ones. I don't know if this bridge had none, or if they didn't get the job done.
Anyone know about backup steering power on these vessels? I know they typically keep emergency generators, but does this provide adequate steering power?
Collision means nothing without magnitude of force.
A glancing blow is completely different from a direct hit. And the amount of Newtons behind the blow completely changes the outcomes. A small ship versus a loaded container ship is a completely different force.
I doubt many bridges would take a full speed, fully loaded container ship directly to one of their supports and survive it. Certainly the most celebrated bridges have a better chance of surviving but I doubt any second tier, lower traveled routes would.
Collision with what? I'm pretty sure that with a sufficiently massive ship sailing fast enough, one could take down any bridge. Hence I'd think there are limits which ship may approach at a given speed. Was one of those limits perhaps exceeded?
separate but pertinent question: what was the mv dali's air draft? (FSK bridge's clearance is 185'/56m) was the container ship going to fit under the bridge, i.e., perhaps the incident was an aborted attempt to crossing under the bridge?
separate but pertinent question: what was the mv dali's air draft? (FSK bridge's clearance is 185'/56m) ...perhaps the incident was an aborted attempt to crossing under the bridge?
Is there a reason we don't force ships above a certain side to always approach a bridge like this perpendicular in the main channels? Seems like a trivial thing to implement immediately and makes this never happen again.
That bridge looks like its almost entirely made of just trusses. It's hard to imagine how one might expect it not to collapse when everything holding it together is so thin.
You cannot put the entire weight of the 70's safety culture to an engineer "showing off"
I bet there was a much more complex and nuanced analysis which included crossing ship dimensions, budget, time to completion, available technology, composition of the local seabed etc..
Designing a bridge is proper engineering and not that easy.
DALI (IMO: 9697428) is a Container Ship and is sailing under the flag of Singapore. Her length overall (LOA) is 299.92 meters and her width is 48.2 meters [1].
Based on the track, it appears the ship changed course slightly and slowed as it approached the bridge [2].
That's clear in the livestream video too. It's like it was fairly on track then changed to head straight for the pylon. A lot of smoke starts coming out of the funnel at the same time as the course change, and the ship's lights go out before impact.
Thanks for the link to the track. That's the first thing that I've seen that showed that I guess it's regular for these ships to pass under the center of this bridge. Is that correct?
If so, what I'm still not understanding is why ships are allowed to make that passage all on their own without any backup like a tugboat and why the bridge doesn't have secondary protection of its pillars. Because with a track like that and lack of either of those things, a catastrophic collision seems inevitable.
Does anyone know why the ship would make a sudden hard right during a sequence of power failures?
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 force.
I am also a bit surprised at how many people don't grasp this or grasp engineering, magnitude of forces and design principles.
> Everyone being surprised at the bridge collapsing needs to reconcile with the amount of force that struck the bridge ... I am also a bit surprised at how many people don't grasp this or grasp engineering, magnitude of forces and design principles.
A spokesman for CalTrans claimed today that Bay Bridge could have taken the same hit without damage, thanks to fenders that protects all pylons for all bridges in the San Francisco Bay Area (1). Cargo ships are heavy, yes, but it appears we have the technology to prevent bridge collapses due to these sorts of collisions today.
1. "The Bay Bridge’s fenders insulated the span during the 2007 incident, so that the Cosco Busan ship struck a bumper, never hitting the bridge itself, Ney said. He noted that fenders on Bay Area bridges should be able to handle a ship traveling at 8 knots, the velocity at which the ship hit the Francis Scott Key span."
That may be so and I appreciate CalTrans confidence in the matter. I however would never want a similar set of circumstances to strike the bay bridge and have to test it.
It is a very different bridge design (assuming were talking about the Oakland to treasure island portion) and it is built in earthquake country.
I'm not saying there shouldn't have been fenders or other protective measures. I'm saying that the amount of force on a direct hit that STOPPED that the ship dead in its tracks - that bridge was not going to withstand it and I do question what would happen to the bay bridge. Again I appreciate the confidence of CalTrans to reassure the commuters but I have seen government officials express too much confidence before.
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.
My family and I drove through the Ports of LA/Long Beach on vacation last summer. A port is basically an entire city dedicated to getting things in/out of the water. Takes 15-20 minutes to drive through. You can't imagine the number of cranes/lifts. It's worth the drive through.
This ship was carrying ~5,000 TEU (Trailer Equivalent Units). Imagine 5,000 fully packed semi trucks crashing into the single upright of that bridge.
Even at 7.5 knots (~10mph) the bridge stood no chance.
That's fair. If you don't live in a major port city you likely don't understand.
Maybe we should reframe it to a more familiar territory. It could be the equivalent of a second tier unsophisticated, unsuspecting, dated website with a relatively small amount of traffic hitting it being hit by a state sponsored actor DDoS attack and expecting the website to survive.
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.
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.
> More than a train going from full speed to a full stop.
I wonder. This ship might have massed about ten times a typical freight train on the heavy side, but the train is going to be moving a lot faster than a ship navigating in port, right?
To be fair I am truly surprised at the comment thread here and people being surprised that it collapsed and the lack of understanding of magnitude of forces. I always think of HN as a fairly educated group with a large portion of engineers (skewed heavily towards software which doesn't always have a background in the physical environment).
I don't intend to sound pretentious or condescending. Maybe its more that I need to reconcile with my own expectations of the community level of knowledge/domain of expertise.
I rather have a high bar of expectations than a low bar though to be honest.
The lights on the ship were going off and on, and it appeared to be smoking before hitting the bridge. Does not look like they had much control at the time.
Clip here, beginning at 1m23s, shows a (sped-up) edit of the ship approaching the bridge, with lights going out, on, and out again immediately prior to impact:
“ The Francis Scott Key Bridge in Baltimore, Maryland which crosses the Patapsco River has reportedly Collapsed within the last few minutes after being Struck by a Large Container Ship; a Mass Casualty Incident has been Declared with over a Dozen Cars and many Individuals said to be in the Water.”
Season 2 of The Wire is the single greatest work of television I've ever seen. It's as rich as a novel, as tragic as something out of Shakespeare. Seriously. If anyone hasn't seen The Wire, do yourself a favor and give it a watch.
It's always wild that Season 2 seems to be polarizing, it is very different but it's so compelling. Tragedy is really probably the most complete way to describe it.
But yeah the short scenes of "that's my f*ing town" and the "they used to make steel there, no?". I know the first one takes place right next to the bridge because they say they are at Fort Armistead. I assume the latter is in much the same place since I thought they are looking across the river at Sparrow's Point.
Also relevant to season 2. The US seriously lacks dredging capacity, because we only allow US built dredges to operate on our ports. Only 1-3 of the top 50 highest capacity dredges in the world qualify. Bloomberg Odd Lots has a great episode about this.
+1 I recently watched the whole series again after I subscribed to HBOMax. I hadn't watched it since 2008, when I watched in SD using DVDs from my original Netflix subscription.
Aside from the new story details I caught and the general great acting, I was struck by how the series captured a the technology transition going on at the time. Payphones and typewriters shift to classic feature phones and PCs with CRTs. Then camera phones enter the picture.
Readit News
He says that at about 1:24 AM the ship loses power (from video feed) while traveling 8.5 knots.
at 1:25.30 power is restored.
at 12:25.59 the ship shows smoke. The ship has already drifted in the channel. It is believed that at this time the ship applied full reverse power as evidenced by the black smoke. (My analysis: the ship drifted but hasn't turned in the channel, more of a translation)
By 1:26.45 the ship has obviously turned in the channel pointing at the pier. Full reverse would cause prop walk to change heading angle;
1:28.52 impact at 7.6 Knots. Camera says 1:28.52, AIS reports the ship still moving at 1:29:35
https://www.youtube.com/watch?v=N39w6aQFKSQ
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 brakes realizing misalignment. Obviously 2-3 minutes is not enough to stop 100,000 tons at 8.5 kts, since it only got to 7.5 kts before crashing. Power loss may have caused total rudder loss.
Similar to a car that hits ice, wheels have arbitrary alignment when they reengage road, when power starts being delivered again, car swerves towards concrete barrier even with brakes. Driver with limited crash experience is mostly just panicking and stomping.
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?
Edit: Also, economic disaster for Baltimore.
> (Wiki) The Port of Baltimore generates $3 billion in annual wages and salary, as well as supporting 14,630 direct jobs and 108,000 jobs connected to port work. In 2014, the port generated more than $300 million in taxes. 1st in automobiles, light trucks, farm and construction machinery, imported forest products, aluminum, and sugar. 2nd in coal exports.
Edit2: Bloomberg has an economic look including info on autos. ~$500 million in March 2024 so far. Honda, Mercedes, Subaru likely worst hit. https://pbs.twimg.com/media/GJmvXiCWkAAgDcE?format=png&name=...
3,600 commercial trucks / day. Hazardous material transport has a 30 mile detour. Baltimore had $350 million of insurance. However, Brent Spence Bridge is noted for cost comparison at $3.6 billion and 1/5 the length.
Baltimore StreamTime also has live view with ongoing discussion. https://www.youtube.com/watch?v=83a7h3kkgPg
The fact that ship was able to reverse hard ( as evidenced by the slowdown), indicates to me that the prop was most likely still attached to the propshaft and hadn't flown off to mangle the rudder.
We still don't know exactly what happened on board, but it is interesting to work through possible scenarios.
Pilots certainly have experience with ship handling of 100,000 ton ships, that's their job. Pilots coordinate the moves of multiple tugs to assist with docking regularly.
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.
I think you are missing the point.
Clearly I am speculating, but I don't think any more experience would have helped in this event.
Why ? I think what happened today was almost entirely down to not being able to fight the basic Laws of Physics.
Its a well known fact that enormous ships take an equally enormous amount of time and distance to reflect the actions of the captain. You make an input and you see the result a bunch of time and distance later.
Time and distance were, sadly, not on the captain's side today. Physics took care of the rest.
This
> Similar to a car that hits ice, wheels have arbitrary alignment when they reengage road, when power starts being delivered again, car swerves towards concrete barrier even with brakes. Driver with limited crash experience is mostly just panicking and stomping.
is almost certainly not the case on a large ship. The rudder is rotated hydraulically. Loss of power simply causes the rudder to stop moving, it's effectively "stuck". Some ships have manual override using a massive wrench, but it takes hours to move the rudder meaningfully in that situation.
As for this:
> 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?
Probably way more than you think. This is a significant reason why they seem so calm when they show up on the bridge. They just hopped from a relatively tiny pilot boat or tug onto a massive ship, possibly with significant sea state. This can be some Indiana Jones level crazy.
https://www.youtube.com/watch?v=18VF8WXWfZw
https://youtu.be/C8ER9Ladqg4?si=Ijwhu90iJi8WPAas&t=226
Pilots are very seasoned mariners who have seen multiple losses of power, and pretty much everything.
Now, back to point 1: bridge team. I have seen a captain the crew trusts execute flawless maneuvers even in exigent circumstances. I have seen a captain the same crew doesn't trust fail repeatedly at everyday things.
We don't have the whole story yet. What happened on the bridge? What happened in the plant? Why did power drop? Did they flood an online generator with diesel oil? I ask because I've seen that happen. Did they blow an exhaust manifold? Seen that. Did they trip the plant by getting preparatory checklist work backward? Seen that. Did they go all back full immediately? Possible that they couldn't ring the order if they dropped power. Was there panic on the bridge (bad sign) or was there grim fortitude to process checklists that would never help (better sign). In any case, no doubt the captain is done. Probably happy to never drive a ship again after that, tbh.
I would hope, given the economic and humanitarian consequences of a crash, that we have simulators for this
Or even if so was it just too late when it all went down and it wouldn’t have made a meaningful difference?
Wouldn't the ship's insurance be the one paying here?
And I assume there will lawsuits to recover costs as this caused economic damage and risk to life (8 people unaccounted for at current time).
Also, there's a lot of mass concentrated in that ship. It's the equivalent of hitting a window with a sledgehammer. Small recreational vessels could probably crash into those pylons all day long.
If you do the math, you find that it’s just an astronomical amount of momentum, and there’s no effective defense for a bridge that needs support in more than 30 or so feet of water.
The bridge style in question
> Conversely, continuous truss bridges rely on rigid truss connections throughout the structure for stability. Severing a continuous truss mid-span endangers the structure. However, continuous truss bridges do not experience the tipping forces that a cantilever bridge must resist because the main span of a continuous truss bridge is supported at both ends.
* https://en.wikipedia.org/wiki/Continuous_truss_bridge
* https://en.wikipedia.org/wiki/Francis_Scott_Key_Bridge_(Balt...
So taking out one end basically takes out the whole thing.
I would not be surprised that when they build the replacement, it will be a design where the individual components are more self-resilient, like:
* https://en.wikipedia.org/wiki/Cable-stayed_bridge
The engineering best practices, budgets, and needs may have been different fifty years ago. Cargo ships were also a lot smaller fifty years ago.
I ended up with no injury, not even a bruise as far as I can remember (who would count bruises as a kid), but definitely with an intuition to respect mass.
The strongest man in the world probably seems pretty solid. Put him at the bottom of a 3 degree grade and release the brakes on a full tractor trailer and he'll seem fragile too.
The knee is like this too. It lets you stand, run and jump just fine, but you can knock down an opponent with a relatively mild lateral impact to the knee.
Much more of the bridge collapsed than you might think, though, far from the impact.
Deleted Comment
A looks like 'barely a bump' M is what got the bridge.
Deleted Comment
Dead Comment
That’s such a ludicrously low bar that I’m not even sure this would qualify as a compliment to these alternative producers.
Deleted Comment
It is quite common and vessels often have outages that leave them Not Under Command. Usually they are safely at sea when this happens and they can drift for hours without causing problems. But of course there's always a possibility of it happening at exactly the wrong moment.
The reasons for this are the usual: lack of redundancy, lack of maintenance, overworked and understaffed crews, etc. etc. The book lays out how ships are pretty much designed to be floating disasters and the Class societies (essentially privatized regulators) are in the pockets of the builders, and they are so captured that they make rules that make it difficult to make safe vessels.
For instance, he was trying to design multi-screw vessels but the rules now assume single-screwed ships and it can be impossible to design in additional shaft alleys and still conform.
But the ship's pilot [1] (not captain) should know exactly how the boat will handle and the exact course of action. Pilots are extremely well paid ($200-$400k) and the tests are very stringent. Friends have told me that the Narraganset Bay pilot test involves drawing every shipping navigation bouy on a map by hand to within ~200 yards from memory alone, compass, ruler and scaled map provided.
It is insane for a 100,000 tonne vessel, that takes so long to stop due to its incredible inertia, that can find itself many thousands of miles from land, to rely on one engine, one gearbox, one shaft and one rudder; without sufficient secondary and tertiary back-up systems. Why was there no battery back-up, or motor on the shaft? Surely the bow thrusters should have a battery back-up to stop such a lurch to starboard.
How can all of the generation and all electrical busbars fail at once? Even if the fuel was bad, surely the generators should draw on separate fuel tanks. For such a large and relatively modern ship to suffer a total power failure is complete corporate incompetence.
If, as some allege, the refrigeration containers were causing problems, and total power outages occurring before sailing, the vessel should not have sailed, certainly at night. If this is the case, The Master needs locking up. But, poor man has to take the blame, because he is cheaper than a Danish Master and his Singaporean employer (if he is employed and not a contractor) also operating in a cheaper flag state than Denmark. The Singaporean Company also needs hitting hard if the culture was the cause of the Captain sailing after such alleged pre-sailing power outages.
Maersk outsource to reduce personnel and running costs. They use the cheapest crews, cheapest ships and need hitting very very very hard. We might then stop this culture of wealthy shipping companies using every method possible to avoid complying with IMO and more rigorous Nation State standards, operating in the shadows and ducking accountability and responsibility.
I think it was something like bad fuel killing the generator.
[1] - https://warontherocks.com/2021/10/cant-sail-away-from-cyber-... (2021)
I’m trying to find a color coded current map. Wind too. I wouldn’t expect wind or current to cause the pronounced heading change that is visible. The drift seems possible.
Note: I’m an experienced dinghy/keelboat sailor, but lack virtually any experience driving boats under power, much less commercial vessels
What I am wondering is: why couldn't the bridge have been blocked off preventing casualties? It seems like more than just the boat and operators' failing if there's no time or secondary precautions if such failures occur.
I wonder if it makes sense to protect bridges with pylons like they have in front of buildings to stop cars and trucks.
Most (all?) of the people on the bridge were contractors repairing potholes.
> I wonder if it makes sense to protect bridges with pylons like they have in front of buildings to stop cars and trucks.
They're called "dolphins" and some bridges do have them.
Dead Comment
But why not (or did it?) also just blast its horn repeatedly, drawing attention so people on or near the bridge would notice it and realise something was wrong and perhaps even where it was headed?
I'm sure it's not allowed generally and not the protocol and whatever ... But it does seem like a common sense & do whatever you can sort of situation to me?
Hard to blow your electrically driven horn when you've lost power.
It's hard for people on the bridge to understand what that means. The more it blasts the horn, the more likely people to turn around, stop and maybe get their phones out to take a video what strange thing this ship is doing. By the time they realize the impact is imminent, it's too late, unless they take a helicopter ride.
Deleted Comment
Is this similar to Boeing for the shipping world? I realize it is early to come to any conclusions.
The question of this being a rare one off vs container companies deprioritizing safety protocols is what I am interested. The power failures make me go down this logic of thought.
Maersk/ZIM rent container ships from another company who makes them and drive them around.
These are completely different companies. A more correct comparison would be something like Jetblue or American Airlines.
But I seriously doubt there is the result of some kind of profit hungry CEO. However I cannot with 100% say it's not until we find more details. But I feel confident enough to avoid the tin foil hat.
I'm hearing there were at least 20 cars and a truck on the bridge, plus construction workers, at the time; my heart goes out to those families
According to current reports, the Maryland Transportation Authority Police responded to the ship’s “mayday” and stopped traffic in the minutes before the catastrophe, but 6 construction workers are still unaccounted for.
https://www.baltimoresun.com/2024/03/26/key-bridge-collapses...
I lived <1 mile from it at the time it went down, and had crossed it earlier in the day on my commute.
Edit: Maybe I'm just tired and need more sleep.
I think that's called "having feelings". Nothing wrong with it.
I worked next door to the church that was shot up in Charleston and felt similarly moved despite not knowing them, never having been inside the building, and not having even been a Christian at the time.
It is a bit strange at some level - not having any true connection beyond proximity but you should probably worry if you _don’t_ at least feel a little something.
I would be much more concerned if you didn't feel devastated by this and you didn't want to cry.
What you're describing is a normal human reaction to a tragedy.
I'm wondering if that's how they stopped almost all of the traffic. Flip a switch, most people stop, a couple of assholes blow through the caution and FAFO.
The 295 bridge collapse a decade ago was similarly shocking
U.S. infrastructure is beyond crisis level.
I think this is most harmful for commuters.
Blocking the Baltimore harbor is brutal although I suspect the passage will be cleared as quickly as possible.
Does anyone know if modern construction standards would require more stability after a ship collision, or is this still how we build bridges?
No matter(1) the engineering there is no pretty much way to not lose the whole large middle area and left area leading to the destroyed pillar in that situation.
Such a collapse crates so much force (tension vibrations etc.) so that the collapse of the section right of the right pillar is not unreasonable.
The only question is if the impact should have made the pillar collapse.
But a loaded container ship is ... absurdly massive I mean they are like multiple high raise building (but not sky scrapers) standing squished together side by side. So the force it can apply is huge and if cargo moving in it there will be force applied to whatever it crashes into even after the initial impact.
And looking at the waves caused by impact with the base it was at least 8m high I think (depending on the container ship). So that wasn't a "slow moving" impact. And even slow moving impacts with container ships can tear apart a solid jetty.
So while the US has issues with infrastructure maintenance idk. if anything but building a many pillar bridge would have made any difference. And building a many pillar bridge might not be very viable depending on the under water landscape and water use under the main area.
EDIT: Looking at pictures with daylight where you can try to estimate the high of the ship using containers I would say the waves where handwavingly 4 containers high so ~9.5m and it also looks like the ship might have embedded half of the pillars fundament into/under itself (but it's a bit hard to tell to the angle of the picture). I think if that's the case probably the huge majority of bridge pillars of past and presence would have collapsed.
The MV Dali (IMO#9697428) is a little over 95000 GT, or ballpark-ish probably around 114000 tons loaded (and it seems to have been loaded, which would make sense on departure). If it was going even 5kn (2.6 m/s) that'd be about 300 million newton-seconds, or about 3.3 times the momentum of a large jumbo jet like a 747 shortly at cruising speed (around 560 mph). It'd still have the same momentum as said jet if it was going just 1.5kn. The ship of course is enormously more stoutly built and the force is going to be transmitted far more directly into whatever it hits vs into explosions driving mass elsewhere.
I've read that both on water and in space for that matter enormously massive objects moving very slowly messes with human perception and "common sense", it "feels like" something moving along smoothly and slowly should be stoppable or come to a stop. Enormous momentum and forces can be terrifying things.
But I guess I thought that maybe there was... typically some kind of earthen buffer around the pillar to prevent such an impact?
That's probably impractical too, I guess.
I guess I just didn't realize ~$1bn bridges were one fluky ship accident away from total collapse at any given time. I think maybe I prefer my previous state of ignorance, to be quite honest....
Exactly. It is only the scale and the viewing angle that makes it seem slow moving.
Watching this video (https://www.youtube.com/watch?v=qJNRRdha1Xk) shows that the ship was incredibly close to the bridge in the first place, even prior to the supposed failure. It's a bit bewildering to me, with my current knowledge, that this scenario wasn't envisioned prior.
When any piece in the chain of those forces breaks, the entire structure loses ability to transfer forces and breaks.
This arrangement is what allows us to build these structures in the first place. There is careful calculations of forces and risks and allowance for margin for error and unexpected events. But, unfortunately, in many cases those do not include ramming things with a large container ship...
I would be interested to know some calculations with factors like: expected bridge lifetime, chance of being rammed per year, cost of making supports strong enough plus an extra safety margin to survive maximum ramming force, cost of having major commercial shipping route unusable for an extended period.
And in practice only bridges that "barely" stand are economically viable
I guess we can be happy failure like this is rare, and that the bridge was not busy: reports indicate 13 cars, and about 7 persons still missing. This could be so much worse.
The best way to think about measures is after we know the full chain of events that have lead to this.
On this bridge, the main section of the bridge is supported by four spaced pillars, making three main spans there. One of the middle two towers was hit, so this should affect two of the three spans. But it took down all three of them. A span that was supported on both sides by intact towers still came down. That is what I find most surprising here.
A bridge that could stand the loss of a single support pier without any significant collapse would obviously be preferable -- but that's a big ask. I'm not a structural engineer, but I am aware of scaling laws [1] and it feels to me that those scaling laws are going to mean that increasing the margin of safety by x is going to increase costs by x^n. For a project like this one, where cost was apparently the deciding factor over a tunnel, that matters.
[1] https://galileo.phys.virginia.edu/classes/609.ral5q.fall04/L...
Well for starters, there's a better chance of less (or ideally no) people forced to get their feet wet and go missing or die from drowning or hypothermia.
> "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-...
It's pretty similar to this one.
[1] https://hackaday.com/2015/11/18/suspension-bridges-of-disbel...
Anyone can build a bridge, but it takes an engineer to barely make it stand.
It's a subtle distinction that I don't think many in the digital realm quite grasp either i.e. far too many over-engineered technical solutions for features and products that aren't even desired
Do all bridges we build need to be able to withstand the force of an entire shipping container bridge hitting it at high speed? What planet should an engineer think that a shipping container has managed to veer off course so badly that they hit a bridge at full speed, fully loaded? That is a sad and significant outlier event.
Deleted Comment
There are cities with skyscrapers near airports, which depend on the airplanes not hitting the skyscrapers.
Having a large force strike perpendicular to gravity is just not something it's designed for at all. All it ever has to handle in the form of force from that direction is wind, and that's absolutely nothing compared to a fully laden container ship hitting it.
When the Golden Gate needs replacement, the Marin NIMBY's that didn't extend BART to the north bay are going to be sad (more likely, their children will be).
Deleted Comment
Deleted Comment
Also, if the ground is sloped, it will act like a ramp, lifting the ship out of the water. The loss of buoyancy means its weight will push downward on the ground below it. An increased normal force means more friction, thus more stopping ability.
That is exactly what they did around the pylons of the large Öresundsbridge between Denmark and Sweden.
Many revolved around the unlikelihood that a building would collapse the way the towers collapsed just due to knocking out a few floors at the top. But the truth is all these mega structures are quite fragile and can instantly collapse in unintuitive ways.
https://i.pinimg.com/736x/1c/6e/f8/1c6ef8db981c77b1bd7809827...
Ironically there are power lines running in parallel that have much more substantial protection, here you can see the powerline protection and the tiny bumpers...
https://patabook.com/news/wp-content/uploads/2024/03/cbsn-fu...
Doesn't sound plausible to me. Very large Panamax ships were used in the 1970's when the bridge was built.
A glancing blow is completely different from a direct hit. And the amount of Newtons behind the blow completely changes the outcomes. A small ship versus a loaded container ship is a completely different force.
I doubt many bridges would take a full speed, fully loaded container ship directly to one of their supports and survive it. Certainly the most celebrated bridges have a better chance of surviving but I doubt any second tier, lower traveled routes would.
https://en.wikipedia.org/wiki/Francis_Scott_Key_Bridge_(Balt...
Most modern bridges are hyperstatic: if you remove one support, it still stands.
Or at least isostatic: you remove one support or one span, and nothing happens to the nearest ones.
This bridge was ill conceived: you remove one support or span, and it brings down everything like a chain that pulls down everything it's linked to.
It's bad because the "engineer" just wanted to show off.
I bet there was a much more complex and nuanced analysis which included crossing ship dimensions, budget, time to completion, available technology, composition of the local seabed etc..
Designing a bridge is proper engineering and not that easy.
Based on the track, it appears the ship changed course slightly and slowed as it approached the bridge [2].
[1] https://www.marinetraffic.com/en/ais/details/ships/shipid:28...
[2] https://www.marinetraffic.com/en/ais/home/shipid:2810451/zoo...
If so, what I'm still not understanding is why ships are allowed to make that passage all on their own without any backup like a tugboat and why the bridge doesn't have secondary protection of its pillars. Because with a track like that and lack of either of those things, a catastrophic collision seems inevitable.
Does anyone know why the ship would make a sudden hard right during a sequence of power failures?
Dead Comment
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 force.
I am also a bit surprised at how many people don't grasp this or grasp engineering, magnitude of forces and design principles.
A spokesman for CalTrans claimed today that Bay Bridge could have taken the same hit without damage, thanks to fenders that protects all pylons for all bridges in the San Francisco Bay Area (1). Cargo ships are heavy, yes, but it appears we have the technology to prevent bridge collapses due to these sorts of collisions today.
1. "The Bay Bridge’s fenders insulated the span during the 2007 incident, so that the Cosco Busan ship struck a bumper, never hitting the bridge itself, Ney said. He noted that fenders on Bay Area bridges should be able to handle a ship traveling at 8 knots, the velocity at which the ship hit the Francis Scott Key span."
https://www.sfchronicle.com/bayarea/article/baltimore-bridge...
It is a very different bridge design (assuming were talking about the Oakland to treasure island portion) and it is built in earthquake country.
I'm not saying there shouldn't have been fenders or other protective measures. I'm saying that the amount of force on a direct hit that STOPPED that the ship dead in its tracks - that bridge was not going to withstand it and I do question what would happen to the bay bridge. Again I appreciate the confidence of CalTrans to reassure the commuters but I have seen government officials express too much confidence before.
This ship was carrying ~5,000 TEU (Trailer Equivalent Units). Imagine 5,000 fully packed semi trucks crashing into the single upright of that bridge.
Even at 7.5 knots (~10mph) the bridge stood no chance.
Maybe we should reframe it to a more familiar territory. It could be the equivalent of a second tier unsophisticated, unsuspecting, dated website with a relatively small amount of traffic hitting it being hit by a state sponsored actor DDoS attack and expecting the website to survive.
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.
I wonder. This ship might have massed about ten times a typical freight train on the heavy side, but the train is going to be moving a lot faster than a ship navigating in port, right?
Deleted Comment
Who are you even referring to? Are you just inventing a population of people in your mind to flex against here? Trust me, people get it.
Dead Comment
I don't intend to sound pretentious or condescending. Maybe its more that I need to reconcile with my own expectations of the community level of knowledge/domain of expertise.
I rather have a high bar of expectations than a low bar though to be honest.
https://www.youtube.com/watch?v=83a7h3kkgPg
<https://yewtu.be/watch?v=Cs6PrRiIHEw&t=1m23s>
https://github.com/rytsikau/ee.Yrewind/
Deleted Comment
“ The Francis Scott Key Bridge in Baltimore, Maryland which crosses the Patapsco River has reportedly Collapsed within the last few minutes after being Struck by a Large Container Ship; a Mass Casualty Incident has been Declared with over a Dozen Cars and many Individuals said to be in the Water.”
https://en.wikipedia.org/wiki/Ebb_Tide_(The_Wire)
But yeah the short scenes of "that's my f*ing town" and the "they used to make steel there, no?". I know the first one takes place right next to the bridge because they say they are at Fort Armistead. I assume the latter is in much the same place since I thought they are looking across the river at Sparrow's Point.
Aside from great acting and direction, of course.
https://omny.fm/shows/odd-lots/the-1906-dredging-law-that-ma...
Aside from the new story details I caught and the general great acting, I was struck by how the series captured a the technology transition going on at the time. Payphones and typewriters shift to classic feature phones and PCs with CRTs. Then camera phones enter the picture.