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.
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....
It does look reasonable to have such a buffer. But any preventive measure will have limits as what and how serious an impact it can deal with.
In this case the ship this massive is something that is carrying ridiculous inertia, and its highly unlikely even a buffer could stop such an impact.
I think at some point you are better off solving these issues with more regulation(smaller ships)? Instead of treating this as a engineering problem.
The recent grounding of a large container ship in Baltimore's harbor channel demonstrates that a sufficiently massive berm will stop any ship. What's needed is the will to do something about low-probability but catastrophic events (though large-ship collisions, groundings and fortuitously harmless steering failures are frequent enough that this should not have been dismissed as a low-probability event.)
https://www.cnn.com/2022/03/16/business/evergreen-container-...
In this case, the nearby towers supporting transmission lines across the channel seem to be better-protected against ship collisions than the piers of the bridge.
Secondly, I believe riprap would be preferred to compacted soil (though compacted soil did a pretty good job stopping the Ever Given three years ago.)
Thirdly (and rendering the above moot), what's been done around the replacement Sunshine Skyway bridge in Tampa bay (mentioned in other posts here) shows that protection is, in fact, practical.
In view of these considerations, I'm not even going to check if, for example, xoa considered the energy absorbed by the ship (Update: in fairness, I did take a look at what xoa wrote, and I see that it is you who has introduced the figure of 1000 J/M^3.)
For an introduction to a serious engineering approach to this problem, look here:
https://onlinelibrary.wiley.com/doi/epdf/10.1002/stco.200910...
That said, the dolphin-bulwarks around the Tampa Skyway are interesting. I've sailed through similar and not known their purpose other than to observe that local waterfowl like to line up at them ahead of tidal shifts to catch the fish as they're encouraged by the currents through them.
You guys are doing amateur engineering. Firstly we don't even know what happened here yet. Secondly we don't know the nature of the problem we'd have to solve in protecting any span that would have been at that position. (How deep is the water? How far down to bedrock? Geological nature of the soil? etc etc etc)
It seems almost impossible for us as humans to just give the professionals some time and space to work so we can see what happened. I get that. I even engage in it at times. But you guys are stating things with certainty and almost indignation? Come on fellas.
Just say your peace and admit it's just a wild ass guess that's likely to be wrong in the end like the rest of our comments.
ETA: Thank you bmelton for owning that.
You're right that it's amateur. This isn't remotely what I do. To your point though, I don't have that much confidence that the Skyway bulwarks would do -- I'm sure they're more than adequate in preventing strikes from my 40' sailboat. Probably much more than that. My gut tells me they are inadequate to stop the momentum of 100k tonnes at speed, but if they did SOMEthing, perhaps that would be enough to differentiate between bridge damage and bridge collapse. I can't find any details on how it's reinforced, with what, or how deeply those reinforcements are buried, so this too is wild speculation... but I wonder if it isn't somewhat security theater. My wife is already scared of bridges, and we're Marylanders who frequent that bridge and the (much longer) bay bridge -- putting something down there to calm her nerves enough that she isn't panicking for the duration of every crossing is almost certainly worthwhile, but doesn't leave the nerds much to ponder.
Measuring a satellite image in Google Maps [1] tells me the bridge's central span is more than 300 meters.
I Googled the distances before the post but apparently got the wrong value. Danke!
e.g. https://www.japantimes.co.jp/uploads/imported_images/uploads...
In general I share your sentiment society could do more to insure itself against lower-probability catastrophes. But overbuilding every bridge would probably cost more than rebuilding the occasional one that's taken out when an unusual event like this occurs. Maybe in a different environment that would make sense, like a warzone (although I think even then there's more tendency to rely on redundant infrastructure and mobile, power-at-a-point defense).
https://en.wikipedia.org/wiki/Sunshine_Skyway_Bridge#/media/...
Given how the Skyway collapse is burned into the local consciousness, I suspect some of the benefit comes from their visibility.
I truly don't know how the dolphins would fair against a massive ship strike but I can imagine them doing their job.
(ship passing): https://pbs.twimg.com/media/FPgQhy2X0AE8yw1.jpg
I don’t think that is likely? My intuition is that in order to stay seaworthy ships are constructed with more integrity than that.
I don’t have any hard evidence though, just that I have looked at many ship collision/allision aftermath photos and what you describe is not a failure mode I have seen so far.
but only on per-pillar per-direction and with quite a bit of distance between it and the pillar
one some pictures you can see that the ship barley missed one of them due to the angle it was going at
And while I'm not quite sure what it is for the bridge had concrete pillars orthogonal in front of the pillars (this picture shows them well, to be clear I do NOT mean the power line isles: https://www.upi.com/News_Photos/view/upi/7191ba50f17c5a68307...). They would have stopped the ship if it would have went orthogonal to the bridge (i.e. if they mistook where the pillar where in a otherwise normal situation). Through not sure if that was the purpose of them.
Exactly. It is only the scale and the viewing angle that makes it seem slow moving.
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.
One time the pulling cart broke down and we had to switch it for another, but when we took it off the rails we forgot about the "shoe" that is supposed to go between the rail and one of the wheels so it can't move downhill (it was like 1degree of slope so barely recognizable as a slope).
It started moving extremely slowly, and all of us except one tried to hold back the force of the train, which of course was imossible and dangerous. The one who did not try to push it very quickly found the "shoe" and put in place. Initially it did not seem to help at all, the train just continued moving at the same pace, tearing up asphalt with the shoe. It finally came to a stop after about 3-5m(?) which takes a fair bit of time with such low speed, and felt like forever given the situation.
The train tracks headed out into an open road, so it could have been so much worse if it were not for the only person thinking clearly in the situation (he was one of the more experienced in our group).
The only major difference is that they often use a safety air brake system shared across an entire consist (train) that requires “charged” pressure (above atmosphere) to disengage the brake (although I think they have moved to an electronic system that now monitors air pressure in each car individually).
This reminds me of a vivid memory I have. I’d just finished a shift cooking, and out back of our restaurant there were railroad tracks. I had a beer and smoke out there with my shift mate, and a train was rolling by. I thought it would be fun to practice jumping on the train. So I do a few passes jogging alongside it, hopping on and off. Then my buddy, standing still, reached out and grabs a rung of a ladder on one of the cars. It immediately picked him up, but he gripped harder due to being startled. He got ragdolled through the air about 10 feet from where he was initially standing.
Kids, don’t play with trains (trespassing issues aside).
Trains are very scary stuff even when moving at a crawl.
A 110,000 ton ship collision is something the human brain is just not going to understand intuitively.
Yes, hence warnings to amateur boat users (e.g. on a canal boat) not to try to stop a collision with the bank using your arms or legs.
[Edit] Boats can also do things that are unintuitive if you are used to driving a car. E.g. turning round the centre of gravity when you steer rather than following the front wheels.
People would think they could stop them like soccer balls, and lose a foot.
I don't know what sort of speed ships travel in harbors (though I know that they are faster than they appear.) In this case, it was an ebb tide (though within an hour of the low) which might have added something to the ship's speed.
https://tides.willyweather.com/md/baltimore-city/patapsco-ri...
Good estimation! :)
For another comparison, Wikipedia gives an estimate of "Apollo 11 launched from Earth to orbit" at 495 million N s [1]. So this is a momentum that's order-of-magnitude comparable to space launches.
Ship KE = 0.5 * (114000 short tons) * (7.5 knots)^2 = ~7.7e8 J.
747 KE = 0.5 * (510,000 lbs) * (560 mph)^2 = ~7.25e9 J.
747 avg weight = (MTOW + OEW) / 2 = ~510,000 lbs
Posted video of power loss. Also black smoke coming out rear — is that normal? Any clue of what onboard crisis they were dealing with?
What happened will be meticulously reconstructed and everyone involved in this is going to have their lives put under a microscope for years worth of legal battles. I don't think we should rush to judgement or second guess from a position of ignorance.
Also looks like it's emergency vehicles in standstill that are falling, i can't discern any moving cars at collapse?
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.
They are designed to withstand smaller boat impacts because they occur relatively frequently, but cost vs benefit on rare events that are difficult to mitigate is quite different.
The bridge projects I've been on spec 75 or 100 years. Main difference is better protection/sacrificial depth on ferrous members.
The average age of a bridge in the USA is 43 years. But we also have an epidemic of unmaintained bridges.
No bridge made today is designed to last indefinitely. Many different forces will degrade the bridge over time, even with maintenance. Steel stresses weaken it over time. Concrete weathers over time due to salt, chemicals, water, wind, and the steel reinforcements tend to corrode eventually.
Stone bridges may last for an exceptionally long time, but their weight and expense makes them only useful in limited applications, typically as small rail overpasses. Ones that were designed for horse and buggy end up slowly failing as heavier trucks and cars in traffic weaken them.
The same fate lies for timber bridges. When well maintained they can last for 75 years, but it's expensive and requires certain skills. They were also mostly designed before heavier cars and trucks, and for less traffic. Most famous covered bridges today are being closed to traffic due to increased wear.
FHWA provides up to $7 Billion in assistance in maintaining bridges. But it would take at least $125 Billion to begin dealing with the structurally deficient bridges in the USA, according to the ASCE Infrastructure Report Card[1].
Add to this the fact that many bridges in the US are privately owned, and it's the responsibility of the bridge owner to maintain them. But guess what's not profitable for a private enterprise? Maintaining bridges. Despite this, train derailments and property damage continue every year due to unmaintained bridge and train infrastructure.
The executive has proposed funding for repairs, but as usual, it's not enough[2]. So far they've gotten almost half that number of bridges repaired, and pledged another $300M,[3] which is still just a drop in the bucket of what's needed of the backlog; it doesn't address all the new maintenance that will be needed each year.
According to the American Road & Transportation Builders Association, there are 167 million crossings on 42,400 bridges rated in poor condition. [4]
[1] https://infrastructurereportcard.org/cat-item/bridges-infras... [2] https://www.nbcnews.com/news/us-news/biden-has-plan-fix-amer... [3] https://www.whitehouse.gov/briefing-room/statements-releases... [4] https://artbabridgereport.org/congressional/map
Is it impossible for these things to stop happening? No, not at all. But it's probably not going to stop, in this country, because we let private industry get away with whatever they want. If this were the UK the story would be very different.
I mainly made that comment because it still blows my mind the the City Bridge Foundation has been going for 740 years
Though to be clear designed to last 50 years isn't the same as saying it will only last exactly 50 years, or that theirs nothing you can do to extend a bridges lifespan if it's replacement is running a little late.
The bridges we can all name are pushing 100+ right?
They more or less do continuous maintenance during the warmer months of the year.
(So older than 50, but younger than 100)
https://en.wikipedia.org/wiki/Zilwaukee_Bridge
Sticking with the mid-western therme, the Chicago Skyway was built in 1958
I’d argue the Bayonne Bridge raising kinda counts since it was almost a rebuild and more impressive in many ways since it stayed open the whole time.
Meanwhile in the San Francisco Bay Area they replaced the Bay Bridge…
1. Built to last only 50 years to save on materials (as the other commenter noted).
2. Built over literally the widest possible part of the Hudson because the governor got in a pissing contest with the Port Authority and wanted all the tolls to go to the state, which wouldn't have been the case had it been built like 2 miles south where the river is narrower.
3. Designed with zero redundancy, such that a "critical fracture could make the bridge fail completely because its supports couldn’t transfer the structure’s load to other supports." [0]
So yeah if we're being real, 50 years was quite optimistic.
The new Tappan Zee is apparently supposed to last 100 years, though given the incidents with substandard materials being used, as well as ever-increasing traffic, who knows.
That said, driving over a bridge 10 years past its planned EOL and being able to look down directly to the water through gaps in the concrete was always a nice feature though -- who needs coffee when you've got that to get your heart rate up!
[0]: https://en.wikipedia.org/wiki/Tappan_Zee_Bridge_(1955%E2%80%...
Keeping in mind that mid-century Japan and Germany were in ruins and the possibility of nuclear annihilation of urban centers very much at the top of many people minds. 50 years may have seemed an optimistic survival rate of built structures at the time.
https://www.nytimes.com/2006/01/17/nyregion/a-bridge-that-ha...
Its replacement is a self-anchored suspension bridge.
The original western span, actually a double suspension bridge, remains standing, as constructed in 1933, 91 years ago.
Here's an interesting list of major bridges with dates, most of the newer ones being replacements: https://www.carolinadesigns.com/obx-guide/fun-info/bridges/
They even note a rare exception designed to last 100 years with maintenance.
The Millau Viaduct also comes to mind when thinking of famous, iconic modern bridges.
There are now two Tacoma Narrows Bridges. The oldest was built in 1950. The one that infamously collapsed was built in 1940. The newer bridge is from 2007. The West Seattle Bridge was closed due to damage in 2020 and reopened after repairs in 2022. It was originally built in the 1980’s after the previous bridge was hit by a ship. There are two floating bridges on I-90 east of Seattle. One of them sunk during reconstruction work in 1990 and was replaced. Theres also a new 520 floating bridge that opened in 2016. The Hood Canal Bridge (also a floating bridge) originally opened in 1961, sunk in 1979, was reopened in the 1980’s, and large parts of it were replaced in the 00’s.
The Ballard Bridge actually is over a century old! It was opened in 1917. However there was a lot of reconstruction done during the 1930’s. The Fremont Bridge is also from 1917. Both of these bridges span a ship canal that was built between 1911 and 1934. The Aurora Bridge was also built in the 1930’s.
In the DC/MD/VA area, almost all the bridges I can name are less than 100 years old. Woodrow Wilson, American Legion, Chesapeake Bay Bridge, Chesapeake Bay Bridge-Tunnel, Key Bridge, Key Bridge, Nice Bridge, Memorial Bridge, Chain Bridge, 14th street bridges... Some of those were even built after 2000! Also the New River Gorge Bridge in WV is pretty famous and not even 50.
Well, actually, the Key Bridge (in DC) apparently turned 100 years old last year. And I guess the Long Bridge (though not a road bridge) is also over 100...
https://en.wikipedia.org/wiki/I-35W_Mississippi_River_bridge
Makes me want to find the data now. I don't actually known if our bridges are too old, poorly maintained and falling apart early, or if the whole topic is just herd mentality and politics.
Fern Hollow Bridge Mk. II?
There's a list of many more failures at Wikpedia, though international in scope:
<https://en.wikipedia.org/wiki/List_of_bridge_failures>
There are a number of ship-bridge collisions listed, as well as fuel-tanker explosions, which seems to be a surprisingly common failure mode.
Also numerous failures in China, though how much of that is simply a scale effect I can't say.
So it's an issue, but those bridges where also constructed by a far poorer nation so it's not that big a deal.
That's a must more interesting question when discussing the topic of infrastructure.
Sure we've created a lot more money in the last 50 years, but we've also lost a lot of domestic manufacturing. When it comes to something as vital as roads and bridges are we poorer when we have less paper money or when we are less independent in the manufacturing and maintenance of them?
I think people feel poorer because income inequality increased so much. New homes are huge because new home buyers are the upper end of the wealth curve. Same deal with cars etc. Stuff that targets everyone like normal sized TV's ends up being extremely cheap because revealed preferences show people buy cheap when it's an option.
Production per capita may have gone up, but that's (a) likely measuring productivity in financial terms and (b) heavily correlated with an increase in natural resource consumption, especially fossil fuels.
If we want to consider ourselves richer because we are able and willing to use more natural resources today could lead down a dark (and very hot) road.
Compare a modern jet with one from the 1974 and sure many passengers have less leg room but it's hauling both people and 3rd party cargo while still using far less than 1/2 the fuel per passenger mile. Such improvements really add up and include things like engineered lumber using fast growth pines.
Look at the most popular car 50 years ago and you'll see the Ford Pinto. It's slow, unsafe, tiny, time consuming to maintain, fuel inefficient, and missing modern amenities but it was affordable. Inflation adjusted it's roughly the cost of a Mitsubishi Mirage which while better in just about every way is a rough equivalent the reason people are buying crossovers rather than the Mirage today is because people just have more wealth in real terms.
The data I found only goes back to 1965 [1], but from the absolute peak in the 70s to today we've reduced per capita use by around 30%. Over the last 20 years we've reduced it by around 15%, going back 10 years and the reduction is only around 5%. Time scale matters a lot here, as does a definition of what "way downdowm" would mean in real % reductions.
I totally agree we've made use of oil more efficient in things like engine efficiency. We've also found more uses for oil byproducts, which can be good or bad depending on your opinion (and again, on your time scale). If we've improved fuel efficiency by 50% and at best reduced fossil fuel per capita by 30%, we've squandered some of those gains by using more oil for other things.
Whether that's a good or bad thing is really up to opinion, goals one has in mind, and how one weighs the trade offs.
[1] https://ourworldindata.org/grapher/fossil-fuels-per-capita
That chart gives 31% in 49 years 63,836 in 2022 vs 92,635 in 1973, but the numbers are dropping faster each year.
it's not that clear-cut. regulations regarding construction are many times more strict, as well employment restrictions and safety code.
I mean, the things like the transcontinental railroad were built with what would largely be considered inhumanely treated human slaves by today standards -- that kind of 'advantageous hiring condition' thankfully no longer exists.
Stuff like that plus millions of other regulatory nuances that drive the cost of development to be many times more expensive than during the bad old 'wild west' make these kind of value analysis gapped by many years near impossible.
As to regulations, in 2023 an I-95 bridge failed after a gasoline tanker truck fire. They took 12 days to get a temporary replacement that got traffic flowing again. You occasionally see such projects where we need a fix now and then it happens. However, it was a temporary replacement and they needed an actual long term solution.
The difference between such rapid projects and more typical ones include time consuming steps to preventing dirt from settling and causing problems in the future etc. Regulations are filled with such tradeoffs, but that doesn't mean we're unable to move more quickly just that we can afford to do something else.
https://en.wikipedia.org/wiki/The_Iron_Bridge
Opened in 1781, still in service and perfectly safe. Of course, there are no container ships nearby. But I reckon you could sail a container ship under it, given enough water; and to damage the bridge supports, the container ship would need climbing equipment.
1781 isn't many years after the Declaration of Independence.
But that's talking about the tail end of the bell curve not it's center.
It didn't take motor traffic, because when it was built, there was no motor traffic. But the claim I replied to was about all bridges. But it used to take vehicle traffic: the WP article says "In 1934 it was designated a scheduled monument and closed to vehicular traffic."
A tiny fraction reach 500 and so far none that we know of have hit 5,000 though there’s a few possibilities.
For example, if tomorrow we decided to build a new bridge next to every old bridge, average lifespan would half.
> if tomorrow we decided to build a new bridge next to every old bridge, average lifespan would half.
The only way building a bunch of new bridges changes lifespan is if we changed how they where built.
Figuring out lifespan rather than age is at best an approximation after looking at the bridges that didn't survive and the condition of bridges that do, but the uncertainty is low.
And in practice only bridges that "barely" stand are economically viable
That really depends on what is counted as part of the economy and who is doing the valuing.
For example the great pyramids of giza are very solidly built. You certainly don't expect that level of build for every commercial or residential building out there.
Now, on the other end of the spectrum you can have buildings that can collapse on minor earthquakes.
There is a balance somewhere in the middle.
I think there’s also an underlying expectation that any competent ship captain would at least be able to see that they’re on a collision course with the pylon well ahead of time and be able to compensate. Which obviously didn’t happen in this case.
I'm sure captain tried to do anything he can to avoid collision.
A container ship has huge inertia, I don't think any bridge could be built to take a direct hit like that.
Vertical clearance for ship traffic might have been the reason this kind of bridge was built in the first place. Otherwise, something lower and more causeway-like might have been sufficient.
The underlying problem here is that automobiles are inherently inefficient so you either get epic traffic jams or have to massively overbuild capacity, forcing the engineers to deliver as many lanes as they can for the budget.
Unfortunately, nobody who knew it would happen today warned anybody.
Those calculations are really hard: say they had built a tunnel, what are the odds of the same number of people dying in a fire after someone crashes into another car? Would we have needed to spend any money at all if more people had used railroad alternatives to driving and such an expensive bridge or tunnel was not justified on traffic grounds?
https://en.wikipedia.org/wiki/Francis_Scott_Key_Bridge_(Balt...
This was a big point of contention when a local town announced it was replacing the failing asphalt on the section with the most traffic with slabs of concrete. [0] People complained about the price. Meanwhile, over a decade on, nearby asphalt laid with the same renewal project is already cracking while the busy main thoroughfare remains undisrupted by road work.
It's hard to persuade people that long-term investment is worthwhile.
[0] PDF page 10 (print 17): https://www.dot.ga.gov/PartnerSmart/Public/Documents/publica...
That is a very interesting point I hadn't considered at all. Price is an obvious point, but I hadn't considered hazmat.
It does make me wonder how hazmat traffic is handled around Amsterdam. I think they are allowed in some tunnels here.
It makes sense to me that cargo would be restricted, and it's bizarre that it would be related to terrorism (an additional rule isn't going to prevent an attack...).
[0] https://en.wikipedia.org/wiki/Kaprun_disaster
[1] https://en.wikipedia.org/wiki/Gotthard_Road_Tunnel#2001_coll...
It is now a very large port that is completely closed off from the sea.
And two sides of the city no longer linked
The damage from this accident is only beginning.
Even if loss of control of a large container ship was considered in the design of the city, port, and that particular bridge, ships were not even close to the order of magnitude of mass of today's ships.
And, it lost power at almost exactly the worst moment. What are the odds?
I don't know, but I suspect we don't hear much about all the times power is lost at moments that are less than the worst.
Of course, it seems that a high(er) frequency of failures should be taken into account for zones where it is critical, such as in port. I just saw a few days ago that a ship docking took out a couple of cargo cranes (sadly, badly injuring a crane operator); didn't seem like a power outage, more of a misjudged steering.
Have you looked at a map of Baltimore? They're very much linked, you just have to drive a little farther. The only issue will be that all the traffic this bridge previously carried now has to reroute to the bridge farther north, so now traffic will be much heavier.
The direct or short link is now broken. Everyone must now go around the entire harbor, on roads that will now have 40k more cars every day, instead of directly across it. I wasn't saying that some area was a disconnected island, but that many trips will become more costly or non-viable for years until the bridge is rebuilt.
Perhaps I should have said "no longer directly linked", but thanks for the picked nit.
This is casual conversation. Writing quickly and colloquially, with the assumption that "no longer directly linked" or "no longer linked as they were 10min before" is inferred, certainly to anyone who has seen a map of the area. It should also be inferred from the sentence alone, as if the link had been to an island, then most writers would have made the much stronger point, saying "completely cutoff from the mainland" instead of the much weaker "no longer linked" (just because one link is broken does not imply that there are no others).
If you want to comment that "I was confused by your meaning and it could have been more clear if you said X" is a perfectly fair statement.
But deliberately taking absolutist definitions in a casual conversation where meanings can be implied / inferred, is an unfriendly, oppositional, if not hostile stance.
In any case, I apologize if you were offended that I didn't include all the qualifiers and assumed they would be apparent to the reader. Have a nice day.
However, please learn that ambiguity in informal speech/writing is substantially different from errors in formal edited speech/writing, and different responses are appropriate.
In the context of formal writing (e.g., an academic or industry paper, book, etc.) we should expect almost all ambiguity to be edited out, and not allow for inferences in either direction; i.e., your complaint would be valid.
However, in casual speech/writing (e.g., SMS, social media comments, non-formal emails, etc.) it is common and not serious to leave IMPLIED components in the conversation. It is certainly acceptable to ask for clarification such as "did you mean to imply that some area was made entirely inaccessible by that event?". But it is inappropriate to accuse someone of being dead wrong by leaving out the implication.
The request for clarification should result in the speaker/writer saying "ya, I did mean to imply XYZ, not PDQ, thx for pointing that out." — mutually and efficiently finding the truth. The accusation, especially continued insistence on the accusation being the one true correct way, is the way to start an argument trying to establish dominance.
It might also be worth noting that your class of people — those familiar with the Baltimore area — should have been MOST able to recognize that "not directly" was the inferred meaning, since you know it's not linking an island to the mainland. That you chose the hostile "j'accuse — you are wrong!" form of discussion rather than the collaborative friendly "btw, you did not mean to imply that the bridge linked to an island" (and continued to insist on the hostile approach) tells us all that this is more about your emotional state and/or approach to human interactions than about the ambiguity itself.
Have a great week
Random ship hits a bridge.
Shakes fist at sky "the government".
It sounded much more like a common trope, "the do-nothing government just lets things fail, doesn't take action until something fails".
A bridge got hit by a container ship at speed and folks here are talking about this like the bridge was not up to standard, or why there was a bridge there at all when they know nothing about the locale. I am not a structural engineer, but I am going to go ahead and guess that not much would still be standing from a direct hit from a container ship. And from observation bridges like this exist all over the world and don’t regularly get struck by container ships.
It was a freak accident.
If we want to point fingers or question things, perhaps if anything the question is why the container ship lost power repeatedly? Was this a known issue before leaving port?
I know they exist, and perhaps after this they'll exist a bit more.
You're right, I don't. But I do know there are other locales where they seem to explicitly avoid bridges crossing heavy ocean traffic.
I think the whole ship went dark for a moment. That may have had an impact on the rudder, and then some strong current and/or wind, pushing it sideways.
Couldn't see tug-boats.
This is a public bridge 5 years in the making and who knows how long in planning, and people have been extremely lucky that it collapsed at 3am and not in the middle of the day. It doesn't matter at all how unlikely this is in a given time frame if the impact if it happens at any point in time is catastrophic.
Edit: of course there are a ton of other solutions here as well. I am disagreeing with the parent that it is the cars which should get to stay and the container ships which have to move.
Amsterdam has no bridges at all crossing the IJ on the west side (where sea-going ships come from) and only a single bridge on the east side (though there's often talk of adding another). Everything is tunnels.
Rotterdam has bridges (including the famous Erasmusbrug), but only east of the port area. To the west, everything is tunnels. And the largest ships don't even come close to the city center, but dock at the Maasvlakte out at sea.
For both cities, ports have constantly moved closer to the sea.
https://foxbaltimore.com/news/local/as-residents-leave-balti...
>“There’s a lot of people staying [in those cities] and we want to be sure they’re not left with an excess of infrastructure that’s impossible to maintain,” he said. “So what do we do about it?”
I lived in the NOVA area for more than a decade and each visit to Baltimore (every few years) was more depressing. Of course, that's anecdotal but I'll stand by it.
It is hard not to feel a sense of tragedy if you know something about the place. It is written all over the city. The blocks and blocks of boarded up row houses speak for themselves. Now they are tearing them down. Maybe that is for the best, but it doesn't seem like a win.
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.
[I'm very busy, so hopefully I didn't forget/add a few 0s by accident. Anyone feel free to correct me if I did.]
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.
The Öresundsbron (connecting Sweden and Denmark) features both short segments but also with an overhand section in the middle for larger ships to pass through. (1) The great belt bridge (inside Denmark) is slightly higher but has the same kind of profile, one of the largest cruise ships barely making it under it is shown passing in the video below (2).
I think the simple truth is that we're vulnerable to these kinds of accidents unless we build far far sturdier bridges, but at these scales to allow passage of ships of these sizes the cost would just make many bridge projects prohibitably expensive.
1: https://www.norden.org/sites/default/files/styles/content_si...
I was curious about Zealand's other connection, the Great Belt Fixed Link:
> The West Bridge has been struck by sea traffic twice. While the link was still under construction on 14 September 1993, the ferry M/F Romsø drifted off course in bad weather and hit the West Bridge. At 19:17 on 3 March 2005, the 3,500-ton freighter MV Karen Danielsen crashed into the West Bridge 800 metres from Funen. All traffic across the bridge was halted, effectively cutting Denmark in two. The bridge was re-opened shortly after midnight, after the freighter was pulled free and inspectors had found no structural damage to the bridge.
> The East Bridge has so far been in the clear, although on 16 May 2001, the bridge was closed for 10 minutes as the Cambodian 27,000-ton bulk carrier Bella was heading straight for one of the anchorage structures. The ship was deflected by a swift response from the navy.
In Danish [2], but it looks like there's someone always monitoring the sea traffic, and able to close the bridge at very short notice — I assume with the red flashing lights which are used to close motorways in emergencies.
> The eastern end through the Great Belt is international water, and therefore even the largest ships must be able to sail under the bridge. The 254 meter high pylons are therefore dimensioned so that they should be able to withstand the approach of tankers of 250,000 tonnes dead weight (DWT) at a speed of 10 knots. Artificial islands protect the anchor blocks as well as the three outermost piers on the Zealand side and the two outermost ones on the Sprogø side.
[1] https://en.wikipedia.org/wiki/Great_Belt_Bridge
[2] https://web.archive.org/web/20090116051425/http://ing.dk/art...
[0] They expected fuel leaking to cause a devastating fire, but not that the fire would weaken the structure enough to cause the cascade failure that brought the towers down. https://archive.seattletimes.com/archive/?date=19930227&slug...
But my comment was in regards to having to build a really expensive bridge to make it crash resistant. I pointed out that you can instead build a cheap flimsy bridge and put the protection in the water around the pylons.
My impression is that the Baltimore bridge had no such extra protection (?) In that case, it's not really "the best design", right?
The towers failed, in the end, but withstanding the initial hit mattered a lot.
If the design requirement for the twin towers was "be fire resistant enough to let most people out of the building", then I'd say they met that requirement, right?
If the design requirement for a bridge is "continue operating at normal capacity", then that is a very different requirement.
Yes, the towers failed to survive serious damage. But the 40,000 more deaths would have been "socioeconomic trouble", in spades. Even by your own chosen measure, the survival for an hour was a partial success.
> "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-...
[1] https://hackaday.com/2015/11/18/suspension-bridges-of-disbel...
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 broader point is that attempts to blame the bridge designers here are misplaced. It really isn't reasonable to have hoped that they could design a structure that could cope with this kind of failure, within the cost constraints that they had. And cost constraints were a real thing for the designers of this particular bridge.
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
If it is still standing after 1000 years, I would say yes. You cannot build a bridge out of stones with bad engineering - it would collapse under its own weight.
edit: does "well engineered" now means over engineered to some?
People who engineered bridges during Roman Empire had different tradeoffs to consider than people who were building bridges in 20th century.
Standing for a thousand years is rarely an ultimate goal when engineering a bridge although it is possible that Romans planned for longer timescales than us.
If we decided to build like Romans did, there would likely be very little infrastructure and many structures would simply be impossible to construct.
Why? The romans build lots of infrastructure. Roads, sewage, irrigation, .. and they used the materials and technics of their time.
Can't we really do better today, with all our advanced technology?
Or can't we, because everything has to be cheap, cheap, cheap?
I mean, the romans used slaves. That is cheap. But we have machines.
Do you know the movements of the supply and demand curves of the materials required since Roman times?
These types of hypotheticals are a waste of time, and only serve to illustrate hubris, as if something as complicated as comparing Roman construction and resources to modern day construction and resources could be possible.
Well, one can compare the results.
Personally I like things that are build solid and can last a 1000 years.
But I don't think I said the romans build better. They just had a different intention: long lasting.
You implied a whole host of things with this statement, and considering the topic of this thread, also ramming a Roman bridge with a fully loaded modern day cargo ship.
The point is there are so many moving parameters, it is nonsensical to take 1 result of 1 technique from 1 point of time and use that as a basis for what one can expect at other points in time.
"If we decided to build like Romans did, there would likely be very little infrastructure"
Why not? They did not have the intention to make the bridge resistant to such heavy loads, as that was not a use case at that time.
They had the intention to make a bridge to last as long as possible for the traffic at their time. And they surely succeded with this.
Now whether they also could have made a bridge that resists 18 wheelers for 1000 years, well, I don't know.
Also we know a bit more about the romans than just their bridges.
Which is to say "let's just pretend that all of those pesky details do not exist".
But I think the true definition of engineering has to encompass a level of efficiency through design, calculation and rationalization. In other words, echoing what the original commenter said, including only what is barely necessary.
Or by experience and learning from other sucessful bridges? Stone bridges were not new in the year 1000.
There is a roman bridge that was allmost completely surviving all this time, till it was blown up in WW2:
https://en.m.wikipedia.org/wiki/Ponte_Pietra_(Verona)
If they wanted a cheap solution, they would have used wood. But wood does not last a 1000 years.
Personally I salute anyone, who can build something that lasts that long.
"including only what is barely necessary."
And "barely necessary" in solid engineering includes lots of safety margins. Not barely standing.
And yes, that includes not using more than you need, because the more material you use, the heavier your bridge is -> the greater are the forces on the structure itself even with no one passing over it.
There are some fun games out there on various plattforms, google "bridge builder"
Not a scientific simulation of course, but they do show the concept.
The 1000 year medieval bridge we're talking about could have been an efficient design for its time.
But then one must make clear: necessary for what.
I think there is a great overlap between "holds for whatever scheme the prefecture will do to test it while I stand under" and "holds for a thousand years".
There is like a limit where fatigue stress stops being a thing in a cycle graph. Many failure modes is due to penny wise cost cutting.
What is well engineered depends on the goals and the limitations of the state of the art at the time. I would say that a thousand year old bridge might count as well engineered if the goal was a bridge that had a low total lifetime cost.
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.
It’s not meant to be an insult, but a compliment noting that engineers know what the essential parts of the bridge are
It's pretty similar to this one.
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.
You do need need the truss at all. If the truss fails (in any of the three spans), it brings down two adjacents spans.
It's just a show off.
...in other words.
The logistic company running this ship was Maersk. That is the same shipping company that had the ever given stuck in the suez canal a few years ago.
Is Maersk now officially the "Boeing" of shipping?
Saying that Maersk is at blame is like blaming the airline instead of Boeing.. if you want to make that parallel.
https://en.wikipedia.org/wiki/Francis_Scott_Key_Bridge_(Balt...
> In addition to a wider shipping lane, the channel would be marked by a 1⁄4 mi (400 m)-long series of large concrete barriers, and the support piers would be protected by massive concrete "dolphins".
https://en.wikipedia.org/wiki/Sunshine_Skyway_Bridge#/media/...
https://www.google.com/maps/place/Sunshine+Skyway+Bridge/@27...
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.
Why would you anticipate that a container ship would have to hit the bridge? What about the flip side to that... How many bridges have never been hit by a container ship or alternatively how many times have an almost fully loaded container ship come to a dead stop after hitting a bridge?
The reason why I would anticipate a container ship hitting that bridge is because of the video we've all seen. It's a huge ship that is going the slowest it can while still retaining control over the vehicle, unattended, through a tight spot, close to a bridge with zero protection from ship collisions, and all with a ship design that is apparently (according to other comments) effectively impossible to correctly maintain and keep running at all times. So I think the better question is, why wouldn't you anticipate a collision?
There are cities with skyscrapers near airports, which depend on the airplanes not hitting the skyscrapers.
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.
https://www.container-transportation.com/worlds-largest-cont...
The ship that knocked down the bridge could weigh ("DWT") up to 115 000 tons.
Some ships from the 1960s and 1970s:
Universe Ireland: Launched in 1968, it had a DWT of over 300 000 tons.
Esso Atlantic (1977): DWT of over 500 000 tons.
But these were tankers. You're right that container ships were not as big back then.
One of the larger container ships when the bridge was built in 1977 was MV Hamburg Express. It was 280 meters long, 32 meters wide, and had a DWT of 50 000 tons.
Do you really think a 280 meter long ship weighing 50 000 tons would not have knocked down the bridge in exactly the same way?
There were container ships with a DWT of 50 000 tons when the bridge was built.
There were also tankers with 10x that (500 000 tons), so large and heavy ships shouldn't be a Pikachu-face surprise to the bridge designers. If nothing else, the trend in increasing ship sizes was clear to anyone looking at it.
Do you think the bridge steel pylons would have resisted a 50 000 tons ship plowing into them?
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).
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.
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.
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.
Does anyone know if modern construction standards would require more stability after a ship collision, or is this still how we build bridges?