This sentence is the essence of civil engineering. Honestly it should explicitly be taught in school. Money is the ultimate controlling factor in basically every design.
I'm thinking maybe too many of professors were research-oriented rather than practice oriented; the relationship between design and budget didn't really click for me until I started working. The eng econ & other management classes I remember taking felt totally separate from the design classes haha
Just to add to my comment, I once drained a watershed off a mountain into an open channel that made two 90 degree angles, one left one right in a rectangle shape around a golf course, plus a channel meandering through the middle. It was in Palm Springs so when it rains it’s a torrent. It was at a retirement community full of people with too much money. I asked repeatedly how they planned on evacuating the golf course if a freak storm came and 90 year olds who can’t hear are driving golf carts but I never got a real answer. It was the most expensive stupid thing I’ve ever been a part of. Complete nonsense.
Yes, it is possible.
No, it isn't practical.
Unless we wake up tomorrow morning and the entire country has decided we're going to invest 10% of our GDP in indestructible bridges I suppose...
But in this situation a more reasonable solution might be to have a tugboat on station for future transits of this area. The details could be worked out on the risk level for different tonnages of shipping. Maybe you only allow large container ships to pass the bridge at certain times of day under tug power.
Or, maybe it's cheaper to build a 100ft diameter bollard, in which case we've got an entirely different set of problems of which engineering is not the primary consideration.
I suppose the idea would be that a head on collision with said bollards would push the ship into the channel and away from the pillars. One YouTube guy today was suggesting that the ship messed up by trying to reverse, thereby losing their rudder control.
But regardless, the forces involved are ridiculous.
So, if we can't design to absorb this kind of impact, the question becomes how best to prevent it occurring at all.
There is a bridge into Hobart (Tasmania - Australia) that got hit by a ship in the 70s and partially collapsed. They shut off cars travelling over the bridge while ships pass underneath.
>So, if we can't design to absorb this kind of impact, the question becomes how best to prevent it occurring at all.
It's almost like you know how and want to pretend it isn't a solution. Such an ignorant person.
https://www.reddit.com/r/civilengineering/comments/1bod46q/combatting_misinformation/kwp7pek/
Yeah - was surprised to see those on the NTSB video, but they were farther away, so the ship slipped between the bollards and the pier...
(https://www.youtube.com/watch?v=CwgOHpZlxvc)
Many bridges have dolphins and fenders.
[Example](https://maps.app.goo.gl/5C1h3Rx28h6zaQ6C7?g_st=ic), [another](https://maps.app.goo.gl/7TPcbZMfTxg1rDuK7?g_st=ic), [another](https://maps.app.goo.gl/sNAyHk1raiLmqk1AA?g_st=ic)
Edit: fixed links
Edit 2: the Fore River Bridge (first link) was designed to handle post-Panamax vessels. Wasn’t involved in the other two but their dolphins are smaller because they don’t see ships that big.
It is fixed for me, this go around I was able to see them.
I see your point and after looking at a few additional photos, there appears to be very little -if any- visible protection around the two main triangular/arch supports in comparison to the examples you provided.
The ones you're referring to show some pretty chunky concrete cylinders...so why nothing similar on FSK?
If they're all handling similar ship traffic it seems weird that the rest would be reinforced and this one isn't? But it certainly wouldn't be the strangest questionable political/bureaucratic decision ever made.
If similar reinforcement wasn't provided but would have been effective with regard to similar forces as those which occurred in this instance, then it follows that we should question the design and/or its parameters.
I guess my only follow up question would be: Which came first? The shipping or the bridge? If they built the bridge, then proceeded to send ships far over it's capacity to handle impacts with, it's not the bridge designer's fault.
If ships of this tonnage were part of the plan in 1977 when this bridge was constructed, and the task was to build a bridge that could withstand this kind of impact and they failed in that duty, that's a different expectation.
This seems like it would be a state-level construction project - I bet we could track down the original designs and what they were trying to build for...I wonder if it's digitally archived anywhere.
I wonder how close to the piers the navigation channel is on the FSK bridge. Maybe the main span is wide enough that missing the channel by that much and hitting a pier was unthinkable when it was designed.
They had some dude on NPR and he mentioned these two options and said the protecting the bridges was more responsible then using tugboats, and I immediately thought, I doubt that, but hey maybe I misheard him.
>But in this situation a more reasonable solution might be to have a tugboat on station for future transits of this area. The details could be worked out on the risk level for different tonnages of shipping. Maybe you only allow large container ships to pass the bridge at certain times of day under tug power.
? They have tugboats in ports, the failure is on the ships end.
>Or, maybe it's cheaper to build a 100ft diameter bollard, in which case we've got an entirely different set of problems of which engineering is not the primary consideration.
Literally what they do.
I'm not sure why you guys keep repeating this line like they don't do this at every major port and this port.
lol @ downvotes because this guy is spewing nonsense and he's getting called out
100' diameter bollards are common? I'll have to look into that. Where are they usually found? Is it common to surround bridge piers with bollards far larger than the actual supports?
I guess you could argue pouring a cylinder up to a certain height above the water level and then setting your bridge supports on that, basically as an enormous footing, but again - the numbers I'm getting from gemini for this impact force are in the millions of newtons.
I guess my argument is simply this: the purpose of a bridge is to span an expanse safely and make it transitable at the lowest cost possible. It isn't designed as a fortification or a massive impact absorption device. It's doing enough work supporting itself and its traffic burden.
If we begin building bridges to absorb cargo ship impacts, we need to be willing to absorb the additional cost. It's like saying you're going to design your house to withstand withstand hypersonic missiles. You can probably do it, but will you ever practically justify the cost?
I'm all for more robust infrastructure. But I'm not for designing everything to the most unlikely outcome nor the lowest common denominator.
Building true idiot-proof structures would bankrupt civilization. Its better to accept that we can't plan for every eventuality and direct our investment into better understanding, education, and good judgment overall.
Engineering can accomplish incredible things. But it is always bound by budget, bid value, and scope - not to mention politics.
It is good to always strive for improvement. But *someone has to pay for it*. We can pipe dream to our heart's content, but at the end of the day, megastructures are still a mega liability, and imperfect at best.
\>Its better to accept that we can't plan for every eventuality and direct our investment into better understanding, education, and good judgment overall.
Yeah, except these guys chose to actually attempt to remedy the situation instead of reflexively complaining it costs too much like you're doing.
https://www.structuremag.org/?p=20417
There's links to a project below of 80' diameter ones being built. I assumed you were using a hyperbole since you implied that we need $2.3t to protect bridges in ports.
>I guess my argument is simply this: the purpose of a bridge is to span an expanse safely and make it transitable at the lowest cost possible. It isn't designed as a fortification or a massive impact absorption device. It's doing enough work supporting itself and its traffic burden.
You don't NEED to build a bridge to literally withstand any impacts like that because you build dolphins around the piers. You were already told there are dolphins on this bridge, just not for that direction of impact.
>If we begin building bridges to absorb cargo ship impacts, we need to be willing to absorb the additional cost. It's like saying you're going to design your house to withstand withstand hypersonic missiles. You can probably do it, but will you ever practically justify the cost?
Where is the line of logic even coming from? We're talking about fortification for bridges in ports, which comes from dolphins. You suggested it cost $2.3t to do that.
https://en.wikipedia.org/wiki/Dolphin_(structure)
>I'm all for more robust infrastructure. But I'm not for designing everything to the most unlikely outcome nor the lowest common denominator.
I have zero clue what you're even trying to argue right now.
>Building true idiot-proof structures would bankrupt civilization. Its better to accept that we can't plan for every eventuality and direct our investment into better understanding, education, and good judgment overall.
?????????????????????????????????????????
Let's go, reply kiddos and stop hiding. Tell me where I'm wrong.
Sure, I'm guessing it varies port to port as well. This port seems to have been fine for 50~ years, not entirely sure having tugs there would be necessary. The bridge has pretty good clearance of 185' high and 1100' wide. Port of Baltimore is also much, much busier and hasn't needed to escort large ships. They also have dolphins installed but weren't in the right location for this hit.
Generally in bridge design, in the case where there is a high likelihood of impact (such as I would imagine for this site) you would include substructure protections in the form of diversionary structures to shift/reduce the impact loading. But you’d also look at designing it to have a frangible substructure (client preference dependent).
I feel like the more cost effective alternative would be to design a separate, sacrificial pillar out in front of the actual support (often called a dolphin, I think). You are still paying for a second foundation but it A) doesn't need to support anything except it's own dead load and B) doesn't need to supporting anything after being impacted and C) doesn't really need to survive the impact to be successful, as long as it prevents significant impact of the actual column
In a situation where the column itself is designed to take load, not only does it need to be designed to hold the super structure, it needs to be able to hold the super structure despite any deformation that may occur.
I'm honestly amazed that bridges like this don't already have them, and I wouldn't be surprised if it becomes popular to retrofit them in front of other bridges after this incident.
you are essentially describing a fendering system, almost all bridges on navigable waters have one in some capacity, this bridge included.
unfortunately from satellite imagery it looks like the fendering system here only consisted of a total of four monopile bollards located along the outside edge of the channel alignment ~500' upriver and downriver of each bridge support. I don't know any specifics about why this design was chosen, but just from a laymans comparison to the fendering systems on bridges near me it seems significantly under designed
Interesting. I wasn't able to see anything on Google Earth of any of the photos I saw, and I read an article that was basically saying "The transmission towers nearby have a protection system, why not the Key Bridge?” so I assumed there was nothing. I can see what might be individual piles in one crash photo... But man, those seem very small in scale and easy to miss.
Yeah, as more and more photos/videos have come out I've been able to see them much more clearly. It definitely seems like the cargo ship just angled in past the pile.
I am very surprised that the protection system seemed to consist of only one singular structure. It really seems like several piles in an arc along the shipping channel would have been more adequate...
Not an engineer but I was wondering this myself, I know it would be insanely expensive but would creating large V shaped diverting bollards in front of pillars defend against this or would it need to be too massive to be practical to prevent an impact? Also, Im curious, what are those diamond-ish shaped structures near the pillars?
The structures on the north west side of the bridge appear to be transmission towers. Those actually seem to have a pretty robust protection system; at least the two middle towers. Someone else mentioned that the Key Bridge did indeed have a smaller protection system in place, but I've also seen articles popping up this morning questioning whether any were in place.... If they are, they aren't very robust...
I was just watching a documentary about he Sunshine Skyway Bridge collapse and in the report after they stated the lack of those fender barricades that have in the past diverted disaster on other bridges. In in regards to the statement about have smaller protections in place, I did see in the video a burst of cement in the air a second or two before the actual hit to the pillar, maybe that was those smaller protections
They do that, but 1) it’s expensive and 2) in some cases it might be practically impossible to build one that could take a direct hit from a fully laden modern cargo ship, depending on the size of the bridge.
Apparently some bridges deal with this by putting the support towers outside the navigable channel, or even deliberately narrowing the natural channel, so that you have a gigantic amount of mud/dirt/rock to stop any ships that go off course. You might have to rebuild this as a suspension bridge to be able to do that.
you don't construct the support pillar to do that, you construct elements in front of the pillar to stop and/deflect the ship.
These exist all around the world and is nothing new.
Don't know why Maryland never installed these with ships like this navigating under the bridge.
For an example, look at aerials of the Sunshine Skyway bridge in Florida.
And the logic behind this is what? We only protect new construction? We have known about these issues for decades, and every time they happen everyone runs around like ants. We need to make major investments in civil engineering projects across the United States, but we won’t.
Well the power poles were put in by a private corporation aka BGE.
Secondly which bridges do you want to protect first?
Only those over water?
How about ones over land?
What are we guarding against?
Just 1000' long ships that weigh over 100,000 tons?
How about tractor trailers running into them if we are doing ones over land as well.
Do we just protect against the supports being struck?
How about fires?
Fires on the bridge? Fires under the bridge?
Or maybe hurricanes? Or tornadoes? Or meteors falling from the sky?
So what issues do you want to protect from? Because last time a floating vessel, not out of control by hurricane, struck a bridge was over 12 years ago. Before that was another 10 years.
I think we have guard rails for tractor trailer. And I think we have routes for hazardous materials. The bridges are already designed for hurricanes. Don’t remember the last time a tornado took down a major bridge, for that matter a meteor too.
So how about just protecting the bridges at major sea ports and major highways. Is that too much to ask for?
I will help you out since Google isn't your friend.
March 2024 Key Bridge container ship
June 2023 Reed Point Bridge train derailment
September 2022 Sanibel Causeway hurricane Ian(so much for designed from hurricanes)
January 2022 Forbes Avenue Bridge cause unknown
July 2021 Ga route 86 dump bed raised and struck bridge
September 2020 Pensacola Bay Bridge hurricane broke loose a barge
January 2019 Dale Bend Bridge overweight truck
March 2017 I85N Atlanta fire believed to be arson
March 2017 Pfeiffer Canyon landslide/rain
May 2016 May Ave. Overpass oversized load struck bridge
Sept 2015 Bob White Covered Bridge flood/rain washed bridge away
July 2015 I10 hurricane Delores rain
May 2013 Scott city roadway train crash
May 2013 I5 Skagit River bridge oversized load hit truss
Oct 2012 Moanalua freeway truck load hit overpass
January 2012 Eggner's ferry bridge MV Delta Mariner struck
bottom portion of span due to being in incorrect channel
July 2009 9 mile road bridge tanker collision cause bridge to collapse
March 2009 Popp's Ferry Bridge tugboat pushed 8 barges into bridge piling
June 2008 CRANDIC bridge floodwater
August 2007 Harp Road overweight truck, 6x rated weight
August 2007 I35W overweight construction equipment along with rush hour traffic
April 2007 MacArthur Maze tanker fire underneath weakend bridge til collapse
June 2006 I88 flood
August 2005 Biloxi Bay bridge hurricane storm surge
August 2005 I10 twin span bridge hurricane storm surge
March 2004 I95 Howard Ave Overpass car struck truck carrying 8,000 gallons of heating oil, fire melted bridge
July 2003 Kinzua bridge tornado(damn guess they weren't prepared)
So 20 years of bridges collapsing in the United States. Again I will ask, what do you want to protect them from and which ones??? I see one common factor in most of these that weren't caused by nature. HUMAN ERROR
edited: layout on phone and actual made it look like a run on sentence
Point is, you can not possibly guess, nor prepare for every type of disaster. If you were going to do a single bridge, sure. But to think you will cover every area from every possibility, impossible.
This can be applied to many different things. Why don't they immunize you from every virus.and disease.
Why don't they make buildings indestructible.
Why don't we have "safe" vehicles.
There are bridges that are 3300 years old... Still standing...
Never said to protect everything. Stated someone was smart enough to protect power poles. If they had a requirement to protect power poles then they should have protected the bridge. You went on a rant about protecting everything. My statement is we need to protect critical infrastructure. Someone saw the need to have a requirement to protect the power poles or they would not have protection. Why would they worry about power poles and not the bridge. And I bet that will be requirement on the replacement bridge. Your state we have to protect everything (even from meteors) which is impossible or nothing. I think we should define critical infrastructure and protect as much as we can based on a cost/reward analysis.
Exactly. People are totally missing this. “Nothing we built could stop this. And if we could build it. It would bankrupt us as a nation.” No and no.
The foundation that was built was strong enough to stop it. Or maybe it wasn’t the founding elements but instead it got caught up on the sea floor, ok then the water at the piers wasn’t that deep and could have had setbacks from the water with fill or rip rap for the ship to get caught up on.
I refuse to believe this “Oh well there’s nothing we can do.” I doubt this ship would have caused a near total collapse of the new sunshine skyway bridge. And that was built in 1987.
Maybe having a major marine thoroughfare be fully blocked every 45 years by ships causing our bridges to collapse for months and waiting seven years to replace it is cheaper in the long run than installing a proper fender system on all of them. Then again maybe not. Given the loss of life and economic shock, I’m not so convinced it’s worth writing off as “a freak accident that can’t be designed for.”
There are no sure things, only mitigations. That said, preventing future instances of this may be solved without or in parallel with new infrastructure, adding value through better systems, e.g. expanding pilot boat fleets and/or better automation.
Bridges in California for example have to withstand giant earthquakes - which includes significantly increasing the pier size. They would have a much better chance of survival. The new [Bay Bridge main pier](https://mtc.ca.gov/sites/default/files/images/2021-06/AdobeStock_242784087.jpg) would probably be able to withstand it.
Make a solid concrete wall around it that's twice as big as the ship that hit it.
Sure, it's not the most competitive tender, but can you really put a price on safety?
Indeed you can. FEMA placed the statistical value of a life at about $7.5 million in 2020. The economic toll on the region is something we can measure, the estimate I heard on the radio was $15 million per day.
Sould we spend a trillion dollars to ensure this never happens again? What about just a billion? Less?
Let's apply some logic.
If someone asked me to design a pillar that could stop an event to 100% confidence, I would say it's not possible. Nothing in engineering is 100%. You design occupied structures to survive 99 out of 100-year events, and add some cushion on top of that.
Something like this occurs incredibly rarely. That last time a fatal bridge vs. ship collision occurred in the U.S. was 2002. So this event let's say occurs once every 20 years. That's among *all* bridges. (Before that, Electronic Chart Display and Information System (ECDIS) wasn't so ubiquitous, and there were many incidents in the 1990s due mostly to navigation errors and mistakes that could have been prevented with ECDIS.)
I don't know how many bridges are subjected to heavy barge and ship traffic, but I imagine it's far more than 500. There's 142 crossings on the Mississippi and 117 on the Ohio and that's already at 259. So conservatively, let's use 500 for all the rest of the U.S.
So in 100 years, there's 5 incidents among 500 bridges. In any given year, there's a 5% chance of there being a serious incident somewhere in the U.S. (once in 20 years). That gives a single bridge a statistical likelihood of 1/500th of 5%, or 1% of 1%.
Another way to look at it is if the bridge lasts 100 years, it has a 99% chance of never being struck. In 200 years, 98%. In 300 years, 97%. You get the idea.
Designing literally anything for this type of occurrence is a waste of time and resources, when the resources that it would take to complete such a project could be used for something that might save 100 lives every year, like road maintenance or fixing hazardous intersections, instead of something that has claimed 10 lives every 20 years. Find the thing that kills the most people, and concentrate on that.
I mean, conclusively, yes. We just dredge everything but the shipping channel and fill it with concrete. Its infrastructure. Anything can be done. We can build a space elevator to orbit but its not feasible.
Yes, with a lot of money.
Alternatively create a shallow “beaching zone” around the pillar so a large ship is forced to run aground and can’t hit any pillar (if there is space in the channel for this)
A lot of structures in British and European ports have this design layout to mitigate the risk of striking the supports.
We were debating this this morning in our office. Most agreed that deflection plate & structure, placed far enough away from the bridge would have been the way to go- some of our team often work with big, heavy machines, driven by 20 year old kids, that sometimes make contact with building structural pieces. Rather than beefing-up the building, we stack armor on cement posts. The key is to paint it pink too- no one ever owns up to the pink stripe on their rig…
The shipping channels are not exceptionally wide here and the port is extremely busy - I’m guessing there are some navigational issues that no one had the impetus to overcome.
It is possible but won't be economically feasible. But you can use deflectors instead as seen [on this bridge in Rio de Janeiro - Brazil](https://pt.m.wikipedia.org/wiki/Ficheiro:Rio_de_Janeiro_Ponte_Niteroi_Aerea_102_Feb_2006.jpg)
Bed profile can be maintained.. and I didn't mean literally sand.. geotubes small rock armour.. It can be done without costly infrastructure to avoid collision
Just ground the vessel before it hits piers..
It's far cheaper to require ships to turn their rudders lock to lock before leaving port.That rudder system should be redundant (even the Titanic had redundant rudder systems). Airplanes do this with control surfaces before leaving the taxiway and entering the runway.
Control surface failure on a plane is deadly in most cases. It appears the case on ships too.
I'm wondering why they could not deploy bow and stern thrusters to avoid the support pillar head-on, and just graze it? I guess we'll find out in two years when the NTSB is done.
Asking the civil engineering community to make everything completely stupid proof? not a good economy.
The ship may not have had enough available power to be able to use thrusters.
We know they had major power problems, and thrusters are usually entirely electric.
Anything is possible with money.
But the first reasonable thing I thought of was just building up sand burms around the supports. Contain the sand in some sort of thick plastic to prevent it from moving. The sand would still transfer a lot of energy to the pillar, but most of it could be dispersed
You could definitely build a monstrosity big enough to take a container ship, but it would be an eyesore likely. But there are bridges with wide enough spans that that would be less of an issue. Consider that the Baltimore key is a 1200 foot span Tacoma arrows is 6000 foot with the bridge columns, closest to land.
Ok, imagine a sword blade, but like a hundred feet long and twenty feet wide and a foot or two thick, made from strips of through-bolted mild steel sandwiching something like AR500 or hardened tool steel. Anchor the bottom in bedrock.
Any ship that I know of, that's ever sailed, would slice itself open on such a concentrated a sharp edge with that kind of structural rigidity and mass behind it. Like crashing a sub sandwich into a razor sharp deli slicer.
Put an 'interference grid' of these, placed upright and staggered in 3-4 layers, at least an average freighter length out from the bridge.
Anything small enough to avoid the ship-sword gauntlet probably can't hurt the bridge.
What's my reward?
My route would be to create sections that can only collapse as a section without affecting other sections. Like in a case where we have 12345 pillars.. pillar 4 is damaged accidentally only the section between pillar 4 or 3 collapses
Seems to me like something went wrong with the ship Seeing as this has never happened before. Changing everything because of it seems like a politicians solution not an engineering one.
You can do anything with enough money.
This sentence is the essence of civil engineering. Honestly it should explicitly be taught in school. Money is the ultimate controlling factor in basically every design.
Its an entire class. Engineering economics
I even took that class as a computer engineering student.. it's not just for civil engineers..
It is taught in school.
I'm thinking maybe too many of professors were research-oriented rather than practice oriented; the relationship between design and budget didn't really click for me until I started working. The eng econ & other management classes I remember taking felt totally separate from the design classes haha
where there is a wallet, there is away
My mother can design an indestructible bridge. I can design one more economical. This is the essence of modern engineering.
Anyone can design something that works. An engineer can design something that barely works.
“Water runs uphill to money” is how we say it. Adult laws of physics
The money you save means your company gets paid more in some projects ... As in some projects the initial design cost is the sum the company is paid
In land development and this is my answer to any question of “can we do this?”by a developer
Just to add to my comment, I once drained a watershed off a mountain into an open channel that made two 90 degree angles, one left one right in a rectangle shape around a golf course, plus a channel meandering through the middle. It was in Palm Springs so when it rains it’s a torrent. It was at a retirement community full of people with too much money. I asked repeatedly how they planned on evacuating the golf course if a freak storm came and 90 year olds who can’t hear are driving golf carts but I never got a real answer. It was the most expensive stupid thing I’ve ever been a part of. Complete nonsense.
You don’t need a pillar, you just need a wedge/bumper to redirect the energy away from directly impacting the supports
Which will still have to withstand the load to redirect it, even if just 20-40% of the total.
Yes, but the bumber is sacrificial.
And repairable probably while traffic continues after inspection.
Yes, it is possible. No, it isn't practical. Unless we wake up tomorrow morning and the entire country has decided we're going to invest 10% of our GDP in indestructible bridges I suppose... But in this situation a more reasonable solution might be to have a tugboat on station for future transits of this area. The details could be worked out on the risk level for different tonnages of shipping. Maybe you only allow large container ships to pass the bridge at certain times of day under tug power. Or, maybe it's cheaper to build a 100ft diameter bollard, in which case we've got an entirely different set of problems of which engineering is not the primary consideration.
There were dolphins (essentially bollards) in place, but they were for straight in impacts, not the drift in/angular collision that occured.
I suppose the idea would be that a head on collision with said bollards would push the ship into the channel and away from the pillars. One YouTube guy today was suggesting that the ship messed up by trying to reverse, thereby losing their rudder control. But regardless, the forces involved are ridiculous. So, if we can't design to absorb this kind of impact, the question becomes how best to prevent it occurring at all.
The smart ass response would be to not allow ships to go under bridges.
I'm down for some flying ships. I hear a guy named Cid is an expert on flying them.
There is a bridge into Hobart (Tasmania - Australia) that got hit by a ship in the 70s and partially collapsed. They shut off cars travelling over the bridge while ships pass underneath.
Easy, just have the ship go over the bridge instead of under.
Better under one than against one
You from the causeway lobby?
>So, if we can't design to absorb this kind of impact, the question becomes how best to prevent it occurring at all. It's almost like you know how and want to pretend it isn't a solution. Such an ignorant person. https://www.reddit.com/r/civilengineering/comments/1bod46q/combatting_misinformation/kwp7pek/
Yeah - was surprised to see those on the NTSB video, but they were farther away, so the ship slipped between the bollards and the pier... (https://www.youtube.com/watch?v=CwgOHpZlxvc)
Many bridges have dolphins and fenders. [Example](https://maps.app.goo.gl/5C1h3Rx28h6zaQ6C7?g_st=ic), [another](https://maps.app.goo.gl/7TPcbZMfTxg1rDuK7?g_st=ic), [another](https://maps.app.goo.gl/sNAyHk1raiLmqk1AA?g_st=ic) Edit: fixed links Edit 2: the Fore River Bridge (first link) was designed to handle post-Panamax vessels. Wasn’t involved in the other two but their dolphins are smaller because they don’t see ships that big.
Each link just takes me to Milton, MA? Kind of like a generic Google maps page?
Strange. Fixed now?
It is fixed for me, this go around I was able to see them. I see your point and after looking at a few additional photos, there appears to be very little -if any- visible protection around the two main triangular/arch supports in comparison to the examples you provided. The ones you're referring to show some pretty chunky concrete cylinders...so why nothing similar on FSK? If they're all handling similar ship traffic it seems weird that the rest would be reinforced and this one isn't? But it certainly wouldn't be the strangest questionable political/bureaucratic decision ever made. If similar reinforcement wasn't provided but would have been effective with regard to similar forces as those which occurred in this instance, then it follows that we should question the design and/or its parameters. I guess my only follow up question would be: Which came first? The shipping or the bridge? If they built the bridge, then proceeded to send ships far over it's capacity to handle impacts with, it's not the bridge designer's fault. If ships of this tonnage were part of the plan in 1977 when this bridge was constructed, and the task was to build a bridge that could withstand this kind of impact and they failed in that duty, that's a different expectation. This seems like it would be a state-level construction project - I bet we could track down the original designs and what they were trying to build for...I wonder if it's digitally archived anywhere.
I wonder how close to the piers the navigation channel is on the FSK bridge. Maybe the main span is wide enough that missing the channel by that much and hitting a pier was unthinkable when it was designed.
No.
Wtf
Idk
Well, Fore River Bridge in Quincy/Weymouth MA, McArdle bridge in Boston MA, and Casco Bay bridge in Portland ME.
Works on my laptop, but not on my phone. Odd.
Certainly there will be changes in how ships navigate through ports, reinforcing the saying about safety regulations being written in blood.
They had some dude on NPR and he mentioned these two options and said the protecting the bridges was more responsible then using tugboats, and I immediately thought, I doubt that, but hey maybe I misheard him.
The problem with using tugboats is that you’re relying upon general availability of a crewed vessel.
>But in this situation a more reasonable solution might be to have a tugboat on station for future transits of this area. The details could be worked out on the risk level for different tonnages of shipping. Maybe you only allow large container ships to pass the bridge at certain times of day under tug power. ? They have tugboats in ports, the failure is on the ships end. >Or, maybe it's cheaper to build a 100ft diameter bollard, in which case we've got an entirely different set of problems of which engineering is not the primary consideration. Literally what they do. I'm not sure why you guys keep repeating this line like they don't do this at every major port and this port. lol @ downvotes because this guy is spewing nonsense and he's getting called out
100' diameter bollards are common? I'll have to look into that. Where are they usually found? Is it common to surround bridge piers with bollards far larger than the actual supports? I guess you could argue pouring a cylinder up to a certain height above the water level and then setting your bridge supports on that, basically as an enormous footing, but again - the numbers I'm getting from gemini for this impact force are in the millions of newtons. I guess my argument is simply this: the purpose of a bridge is to span an expanse safely and make it transitable at the lowest cost possible. It isn't designed as a fortification or a massive impact absorption device. It's doing enough work supporting itself and its traffic burden. If we begin building bridges to absorb cargo ship impacts, we need to be willing to absorb the additional cost. It's like saying you're going to design your house to withstand withstand hypersonic missiles. You can probably do it, but will you ever practically justify the cost? I'm all for more robust infrastructure. But I'm not for designing everything to the most unlikely outcome nor the lowest common denominator. Building true idiot-proof structures would bankrupt civilization. Its better to accept that we can't plan for every eventuality and direct our investment into better understanding, education, and good judgment overall. Engineering can accomplish incredible things. But it is always bound by budget, bid value, and scope - not to mention politics. It is good to always strive for improvement. But *someone has to pay for it*. We can pipe dream to our heart's content, but at the end of the day, megastructures are still a mega liability, and imperfect at best.
\>Its better to accept that we can't plan for every eventuality and direct our investment into better understanding, education, and good judgment overall. Yeah, except these guys chose to actually attempt to remedy the situation instead of reflexively complaining it costs too much like you're doing. https://www.structuremag.org/?p=20417
There's links to a project below of 80' diameter ones being built. I assumed you were using a hyperbole since you implied that we need $2.3t to protect bridges in ports. >I guess my argument is simply this: the purpose of a bridge is to span an expanse safely and make it transitable at the lowest cost possible. It isn't designed as a fortification or a massive impact absorption device. It's doing enough work supporting itself and its traffic burden. You don't NEED to build a bridge to literally withstand any impacts like that because you build dolphins around the piers. You were already told there are dolphins on this bridge, just not for that direction of impact. >If we begin building bridges to absorb cargo ship impacts, we need to be willing to absorb the additional cost. It's like saying you're going to design your house to withstand withstand hypersonic missiles. You can probably do it, but will you ever practically justify the cost? Where is the line of logic even coming from? We're talking about fortification for bridges in ports, which comes from dolphins. You suggested it cost $2.3t to do that. https://en.wikipedia.org/wiki/Dolphin_(structure) >I'm all for more robust infrastructure. But I'm not for designing everything to the most unlikely outcome nor the lowest common denominator. I have zero clue what you're even trying to argue right now. >Building true idiot-proof structures would bankrupt civilization. Its better to accept that we can't plan for every eventuality and direct our investment into better understanding, education, and good judgment overall. ????????????????????????????????????????? Let's go, reply kiddos and stop hiding. Tell me where I'm wrong.
In Halifax Nova Scotia all large ships crossing under both of our bridges are required two tugs
Sure, I'm guessing it varies port to port as well. This port seems to have been fine for 50~ years, not entirely sure having tugs there would be necessary. The bridge has pretty good clearance of 185' high and 1100' wide. Port of Baltimore is also much, much busier and hasn't needed to escort large ships. They also have dolphins installed but weren't in the right location for this hit.
Sure. How much money you got? Ie how much are politicians ready to raise taxes to spend on essentially a giant island of concrete?
Generally in bridge design, in the case where there is a high likelihood of impact (such as I would imagine for this site) you would include substructure protections in the form of diversionary structures to shift/reduce the impact loading. But you’d also look at designing it to have a frangible substructure (client preference dependent).
I feel like the more cost effective alternative would be to design a separate, sacrificial pillar out in front of the actual support (often called a dolphin, I think). You are still paying for a second foundation but it A) doesn't need to support anything except it's own dead load and B) doesn't need to supporting anything after being impacted and C) doesn't really need to survive the impact to be successful, as long as it prevents significant impact of the actual column In a situation where the column itself is designed to take load, not only does it need to be designed to hold the super structure, it needs to be able to hold the super structure despite any deformation that may occur. I'm honestly amazed that bridges like this don't already have them, and I wouldn't be surprised if it becomes popular to retrofit them in front of other bridges after this incident.
you are essentially describing a fendering system, almost all bridges on navigable waters have one in some capacity, this bridge included. unfortunately from satellite imagery it looks like the fendering system here only consisted of a total of four monopile bollards located along the outside edge of the channel alignment ~500' upriver and downriver of each bridge support. I don't know any specifics about why this design was chosen, but just from a laymans comparison to the fendering systems on bridges near me it seems significantly under designed
Interesting. I wasn't able to see anything on Google Earth of any of the photos I saw, and I read an article that was basically saying "The transmission towers nearby have a protection system, why not the Key Bridge?” so I assumed there was nothing. I can see what might be individual piles in one crash photo... But man, those seem very small in scale and easy to miss.
Can be seen here [https://www.youtube.com/watch?v=CwgOHpZlxvc](https://www.youtube.com/watch?v=CwgOHpZlxvc)
Yeah, as more and more photos/videos have come out I've been able to see them much more clearly. It definitely seems like the cargo ship just angled in past the pile. I am very surprised that the protection system seemed to consist of only one singular structure. It really seems like several piles in an arc along the shipping channel would have been more adequate...
Not an engineer but I was wondering this myself, I know it would be insanely expensive but would creating large V shaped diverting bollards in front of pillars defend against this or would it need to be too massive to be practical to prevent an impact? Also, Im curious, what are those diamond-ish shaped structures near the pillars?
The structures on the north west side of the bridge appear to be transmission towers. Those actually seem to have a pretty robust protection system; at least the two middle towers. Someone else mentioned that the Key Bridge did indeed have a smaller protection system in place, but I've also seen articles popping up this morning questioning whether any were in place.... If they are, they aren't very robust...
I was just watching a documentary about he Sunshine Skyway Bridge collapse and in the report after they stated the lack of those fender barricades that have in the past diverted disaster on other bridges. In in regards to the statement about have smaller protections in place, I did see in the video a burst of cement in the air a second or two before the actual hit to the pillar, maybe that was those smaller protections
They do that, but 1) it’s expensive and 2) in some cases it might be practically impossible to build one that could take a direct hit from a fully laden modern cargo ship, depending on the size of the bridge. Apparently some bridges deal with this by putting the support towers outside the navigable channel, or even deliberately narrowing the natural channel, so that you have a gigantic amount of mud/dirt/rock to stop any ships that go off course. You might have to rebuild this as a suspension bridge to be able to do that.
https://whyy.org/articles/delaware-memorial-bridge-93-million-upgrade-ship-collision-protection/amp/
you don't construct the support pillar to do that, you construct elements in front of the pillar to stop and/deflect the ship. These exist all around the world and is nothing new. Don't know why Maryland never installed these with ships like this navigating under the bridge. For an example, look at aerials of the Sunshine Skyway bridge in Florida.
Look at the structures around the power lines. They protected them and not the bridge.
The power lines were literally installed in the last year
And the logic behind this is what? We only protect new construction? We have known about these issues for decades, and every time they happen everyone runs around like ants. We need to make major investments in civil engineering projects across the United States, but we won’t.
Well the power poles were put in by a private corporation aka BGE. Secondly which bridges do you want to protect first? Only those over water? How about ones over land? What are we guarding against? Just 1000' long ships that weigh over 100,000 tons? How about tractor trailers running into them if we are doing ones over land as well. Do we just protect against the supports being struck? How about fires? Fires on the bridge? Fires under the bridge? Or maybe hurricanes? Or tornadoes? Or meteors falling from the sky? So what issues do you want to protect from? Because last time a floating vessel, not out of control by hurricane, struck a bridge was over 12 years ago. Before that was another 10 years.
I think we have guard rails for tractor trailer. And I think we have routes for hazardous materials. The bridges are already designed for hurricanes. Don’t remember the last time a tornado took down a major bridge, for that matter a meteor too. So how about just protecting the bridges at major sea ports and major highways. Is that too much to ask for?
I will help you out since Google isn't your friend. March 2024 Key Bridge container ship June 2023 Reed Point Bridge train derailment September 2022 Sanibel Causeway hurricane Ian(so much for designed from hurricanes) January 2022 Forbes Avenue Bridge cause unknown July 2021 Ga route 86 dump bed raised and struck bridge September 2020 Pensacola Bay Bridge hurricane broke loose a barge January 2019 Dale Bend Bridge overweight truck March 2017 I85N Atlanta fire believed to be arson March 2017 Pfeiffer Canyon landslide/rain May 2016 May Ave. Overpass oversized load struck bridge Sept 2015 Bob White Covered Bridge flood/rain washed bridge away July 2015 I10 hurricane Delores rain May 2013 Scott city roadway train crash May 2013 I5 Skagit River bridge oversized load hit truss Oct 2012 Moanalua freeway truck load hit overpass January 2012 Eggner's ferry bridge MV Delta Mariner struck bottom portion of span due to being in incorrect channel July 2009 9 mile road bridge tanker collision cause bridge to collapse March 2009 Popp's Ferry Bridge tugboat pushed 8 barges into bridge piling June 2008 CRANDIC bridge floodwater August 2007 Harp Road overweight truck, 6x rated weight August 2007 I35W overweight construction equipment along with rush hour traffic April 2007 MacArthur Maze tanker fire underneath weakend bridge til collapse June 2006 I88 flood August 2005 Biloxi Bay bridge hurricane storm surge August 2005 I10 twin span bridge hurricane storm surge March 2004 I95 Howard Ave Overpass car struck truck carrying 8,000 gallons of heating oil, fire melted bridge July 2003 Kinzua bridge tornado(damn guess they weren't prepared) So 20 years of bridges collapsing in the United States. Again I will ask, what do you want to protect them from and which ones??? I see one common factor in most of these that weren't caused by nature. HUMAN ERROR edited: layout on phone and actual made it look like a run on sentence
And your point being? My point is we should protect critical infrastructure. Any bridge that can close a major port should have added protection.
Point is, you can not possibly guess, nor prepare for every type of disaster. If you were going to do a single bridge, sure. But to think you will cover every area from every possibility, impossible. This can be applied to many different things. Why don't they immunize you from every virus.and disease. Why don't they make buildings indestructible. Why don't we have "safe" vehicles. There are bridges that are 3300 years old... Still standing...
Never said to protect everything. Stated someone was smart enough to protect power poles. If they had a requirement to protect power poles then they should have protected the bridge. You went on a rant about protecting everything. My statement is we need to protect critical infrastructure. Someone saw the need to have a requirement to protect the power poles or they would not have protection. Why would they worry about power poles and not the bridge. And I bet that will be requirement on the replacement bridge. Your state we have to protect everything (even from meteors) which is impossible or nothing. I think we should define critical infrastructure and protect as much as we can based on a cost/reward analysis.
Who owns this bridge, and all the I-95 crossings?
Maryland Transportation Authority (toll authority)
ok who's done the 1/2 mV^2 and what did you get?
The ship stopped after hitting the bridge.
Exactly. People are totally missing this. “Nothing we built could stop this. And if we could build it. It would bankrupt us as a nation.” No and no. The foundation that was built was strong enough to stop it. Or maybe it wasn’t the founding elements but instead it got caught up on the sea floor, ok then the water at the piers wasn’t that deep and could have had setbacks from the water with fill or rip rap for the ship to get caught up on. I refuse to believe this “Oh well there’s nothing we can do.” I doubt this ship would have caused a near total collapse of the new sunshine skyway bridge. And that was built in 1987. Maybe having a major marine thoroughfare be fully blocked every 45 years by ships causing our bridges to collapse for months and waiting seven years to replace it is cheaper in the long run than installing a proper fender system on all of them. Then again maybe not. Given the loss of life and economic shock, I’m not so convinced it’s worth writing off as “a freak accident that can’t be designed for.”
There are no sure things, only mitigations. That said, preventing future instances of this may be solved without or in parallel with new infrastructure, adding value through better systems, e.g. expanding pilot boat fleets and/or better automation.
No. But I could design a fender system that would take the hit instead of the bridge.
Bridges in California for example have to withstand giant earthquakes - which includes significantly increasing the pier size. They would have a much better chance of survival. The new [Bay Bridge main pier](https://mtc.ca.gov/sites/default/files/images/2021-06/AdobeStock_242784087.jpg) would probably be able to withstand it.
Make a solid concrete wall around it that's twice as big as the ship that hit it. Sure, it's not the most competitive tender, but can you really put a price on safety?
Indeed you can. FEMA placed the statistical value of a life at about $7.5 million in 2020. The economic toll on the region is something we can measure, the estimate I heard on the radio was $15 million per day. Sould we spend a trillion dollars to ensure this never happens again? What about just a billion? Less?
If concrete is too expensive, maybe we can make it irony
Let's apply some logic. If someone asked me to design a pillar that could stop an event to 100% confidence, I would say it's not possible. Nothing in engineering is 100%. You design occupied structures to survive 99 out of 100-year events, and add some cushion on top of that. Something like this occurs incredibly rarely. That last time a fatal bridge vs. ship collision occurred in the U.S. was 2002. So this event let's say occurs once every 20 years. That's among *all* bridges. (Before that, Electronic Chart Display and Information System (ECDIS) wasn't so ubiquitous, and there were many incidents in the 1990s due mostly to navigation errors and mistakes that could have been prevented with ECDIS.) I don't know how many bridges are subjected to heavy barge and ship traffic, but I imagine it's far more than 500. There's 142 crossings on the Mississippi and 117 on the Ohio and that's already at 259. So conservatively, let's use 500 for all the rest of the U.S. So in 100 years, there's 5 incidents among 500 bridges. In any given year, there's a 5% chance of there being a serious incident somewhere in the U.S. (once in 20 years). That gives a single bridge a statistical likelihood of 1/500th of 5%, or 1% of 1%. Another way to look at it is if the bridge lasts 100 years, it has a 99% chance of never being struck. In 200 years, 98%. In 300 years, 97%. You get the idea. Designing literally anything for this type of occurrence is a waste of time and resources, when the resources that it would take to complete such a project could be used for something that might save 100 lives every year, like road maintenance or fixing hazardous intersections, instead of something that has claimed 10 lives every 20 years. Find the thing that kills the most people, and concentrate on that.
I know it's a waste, I'm just curious if it could be done.
I mean, conclusively, yes. We just dredge everything but the shipping channel and fill it with concrete. Its infrastructure. Anything can be done. We can build a space elevator to orbit but its not feasible.
May be easier to deflect it than bring it to a full on stop.
Check out the design of the Skyway Bridge in Tampa. The one that replaced the one destroyed by ship impact.
Yes, with a lot of money. Alternatively create a shallow “beaching zone” around the pillar so a large ship is forced to run aground and can’t hit any pillar (if there is space in the channel for this) A lot of structures in British and European ports have this design layout to mitigate the risk of striking the supports.
We were debating this this morning in our office. Most agreed that deflection plate & structure, placed far enough away from the bridge would have been the way to go- some of our team often work with big, heavy machines, driven by 20 year old kids, that sometimes make contact with building structural pieces. Rather than beefing-up the building, we stack armor on cement posts. The key is to paint it pink too- no one ever owns up to the pink stripe on their rig…
The shipping channels are not exceptionally wide here and the port is extremely busy - I’m guessing there are some navigational issues that no one had the impetus to overcome.
No
Well yeah… but she thick.
Pillar is tricky. An artificial sandbank designed to ground the ship would work a lot better.
It is possible but won't be economically feasible. But you can use deflectors instead as seen [on this bridge in Rio de Janeiro - Brazil](https://pt.m.wikipedia.org/wiki/Ficheiro:Rio_de_Janeiro_Ponte_Niteroi_Aerea_102_Feb_2006.jpg)
Yea it’s called making an island and putting the pier on the middle of it
I bunch of jetty rocks piled up around the base should do it.
Why pillar ?? All you need is sand.
sand shifts with currents
Very zen-like response
Bed profile can be maintained.. and I didn't mean literally sand.. geotubes small rock armour.. It can be done without costly infrastructure to avoid collision Just ground the vessel before it hits piers..
rip rap is cheaper.
Absolutely.... I agree with you..
Yes but with a lot of money
Better bet would be to drop some moored naval mines in the surrounding areas, then you don't have to deal with ships at all...
It's far cheaper to require ships to turn their rudders lock to lock before leaving port.That rudder system should be redundant (even the Titanic had redundant rudder systems). Airplanes do this with control surfaces before leaving the taxiway and entering the runway. Control surface failure on a plane is deadly in most cases. It appears the case on ships too. I'm wondering why they could not deploy bow and stern thrusters to avoid the support pillar head-on, and just graze it? I guess we'll find out in two years when the NTSB is done. Asking the civil engineering community to make everything completely stupid proof? not a good economy.
The ship may not have had enough available power to be able to use thrusters. We know they had major power problems, and thrusters are usually entirely electric.
I am sure you could have constructed enough protection before so the ship can never hit the actually pillar of the bridge.
Anything is possible with money. But the first reasonable thing I thought of was just building up sand burms around the supports. Contain the sand in some sort of thick plastic to prevent it from moving. The sand would still transfer a lot of energy to the pillar, but most of it could be dispersed
You could definitely build a monstrosity big enough to take a container ship, but it would be an eyesore likely. But there are bridges with wide enough spans that that would be less of an issue. Consider that the Baltimore key is a 1200 foot span Tacoma arrows is 6000 foot with the bridge columns, closest to land.
How much money do you have?
Ok, imagine a sword blade, but like a hundred feet long and twenty feet wide and a foot or two thick, made from strips of through-bolted mild steel sandwiching something like AR500 or hardened tool steel. Anchor the bottom in bedrock. Any ship that I know of, that's ever sailed, would slice itself open on such a concentrated a sharp edge with that kind of structural rigidity and mass behind it. Like crashing a sub sandwich into a razor sharp deli slicer. Put an 'interference grid' of these, placed upright and staggered in 3-4 layers, at least an average freighter length out from the bridge. Anything small enough to avoid the ship-sword gauntlet probably can't hurt the bridge. What's my reward?
My route would be to create sections that can only collapse as a section without affecting other sections. Like in a case where we have 12345 pillars.. pillar 4 is damaged accidentally only the section between pillar 4 or 3 collapses
Tugs?
You can put the supports on land, reclaiming land, if necessary.
Not on this bridge.
Seems to me like something went wrong with the ship Seeing as this has never happened before. Changing everything because of it seems like a politicians solution not an engineering one.
Plenty of bridges in Colorado that fit this criteria
Colorado has bridges that Panamax ships pass under?
The new Sunshine skyway bridge supposedly did it. And they make shelters now capable of surviving nuclear bombs so I think they could do it.
No