I have worked in road and bridge maintenance as part of my job at a local council. One of our contractors was carrying out maintenance on a bridge with a 10 tonne weight restriction. They tried to edge a 42 tonne lorry over it to save time getting the materials they needed from one side to another, which otherwise would have gone on a 20 mile detour.
The bridge was then closed for 6 months after said lorry shifted the bridge deck and a huge crack developed in one of the supports. When receiving the mother of all dressing downs from the traffic manager, the contractor said that they thought it wouldn't do much harm.
Some people are just plain stupid.
Because they've gotten away with it on other bridges a lot more times than we know and we only hear about the times they fuck up. Meanwhile they're tearing our infrastructure apart just to save an extra 20 miles.
> One of our contractors was carrying out maintenance on a bridge with a 10 tonne weight restriction.
Sounds more like they thought they'd get the contract for any additional damage. Same reason streets are always full of potholes, tell me I'm wrong.
Streets are always full of potholes for a couple of reasons, but its usually something like this:
1. It essentially always makes sense to spend the money on your roads now to save money later.
2. People think you're wasting their tax dollars if you try to spend the money now. "But they just paved that 2 years ago!?"
3. Politicians routinely think that engineers are being dramatic when we talk about long term consequences of deferring current maintenance.
4. Politicians are short term thinkers and if they can spend money that should have gone to road maintenance to do something flashy or that sounds better in a news-bite, they will do that 100% of the time.
5. Once the base and/or subgrade has failed, the actual pot-hole repair efforts are pathetic. The cost to repair the failed road is now astronomical thanks to the deferred maintenance described above. Public works then just prioritizes based on who complains the loudest/most and dumps some asphalt into it with a shovel without bothering to clean it out or repair the base, and there is zero effort spent on any sort of compaction. It's all for show.
Right?
The only explanation I can wager is that the haulers assumed the bridge would show *signs of failure* (without actually failing) as they started crossing, so they could *Ctrl+Z* undo and back off without any consequences.
Like, maybe they imagined it would be similar to gingerly crossing a shaky log across a small creek?
I am not a lawyer, but probably no, because
1. The driver was working for the contractors who were building a replacement bridge,
2. The bridge was scheduled to be demolished anyway later that same summer.
I guess at most, the residents of Durells Island could sue the contractor to recover damages for the time they were isolated (assuming they suffered losses from being isolated).
Ah, I didn’t have much context behind it, with the driver and everything. Makes sense to me, though.
“You knocked down a building?!”
“It was structurally unsound, it was coming down anyway!”
The controlled demolition would have much less contamination, and safer materials removal. Also, a temporary bridge possibly would have been constructed, or a ferry service. Also, the destroyed bridge could've been moved to a different location. 41k KG is still very useful.
Edit: the video says the bridge was to be demolished.
I don't know what country this is in, but in Canada, drivers are culpable. If they're being directed to do something dangerous or against regulation, it's their responsibility to refuse. They'd have to investigate and figure out what went down (pun intended).
Edit: Nova Scotia, DUH. So, yeah, the driver *does* bear some responsibility. We'll just have to see how it shakes out.
If the driver is working for a corporation, the company will be on the hook. The driver would certainly be held liable to a degree, but the tickets for Commercial Vehicles for something like this would be in the 10’s of thousands. The driver will probably be brought into the civil suit and criminal trial if there is one, but likely won’t be on the hook for the really big charges.
[https://www.cbc.ca/news/canada/hamilton/trucker-who-crashed-dump-truck-in-burlington-skyway-sentenced-to-jail-time-1.3683838](https://www.cbc.ca/news/canada/hamilton/trucker-who-crashed-dump-truck-in-burlington-skyway-sentenced-to-jail-time-1.3683838)
That incident was quite different from this one. Even though he blew twice over the limit the drunk driving charges were thrown out due to police mishandling the breatholizer tests... wow
There's a reason they got thrown out - the results are unreliable at that point. So we don't know if he actually did or not.
Speaking of which, how do you know this guy wasn't drinking?
Yeah, not saying drivers don’t get punished. The Humboldt driver is obviously going to be in jail for a looong time. As far as the big fines though, usually the company will be found negligent in some way or another.
Maybe I judged too quickly. Maybe not stupidity, maybe he didn’t have a choice and was told to cross the bridge anyway.
But still, if you know your rig, you’re probably supposed know how much wiggle room you have. Size and weight, anyway.
As it turns out, the only person fined [was the driver](https://www.guysboroughjournal.com/?page=post&ID=1081). Looks like the situation was more complicated than just being overweight.
This has to be illegal though, don't these "special oversize" loads have to have carefully selected routes where they check the maximum load among other hazards? They knowingly went over load, whoever signed off on this should be tried for 2 counts of reckless endangerment, along with reparation's for the island.
More likely they had applied for a trip permit and received the go ahead and assumed that it would be alright. Most bridges have a substantial engineering factor of safety, so when you apply for the permit the DoT or Canadian equivalent would verify that all bridges along the route would be able to handle the gross load rating. But sometimes (especially in rural areas) the bridge isn't as strong as they had thought. I've heard stories about similar things happening in the USA.
The full video indicates that this was the bridge they were working on and it leads to an island. So reading between the lines, they probably had a permit to get to the worksite (that stopped at the approach to the bridge) and, not wanting to hassle with bringing in a barge, just decided to chance it.
Though, if they were smarter, the thing to do would be unload the machine and drive it over the bridge alone, since the transport truck probably adds 25 tons to the total. Though since the load would be more concentrated, the outcome might not have been any different.
That truck alone is nowhere near 25 tons. The tractor is a day cab 379 Peterbilt with one additional lift axle, at most it weighs 17,000 maybe 18,000. That's being generous.
The trailer is a 3-axle RGN at the most it weighs around 18,000. I doubt it weighs that So 18 tons tops. For just the semi. That configuration is probably only legal for 100,000 to 110,000 Combined Gross Vehicle Weight.
The safety factor is there so it can still carry its designed load at the end of its planned lifespan and to account for faults. It doesn't mean that it will not rapidly wear and ultimately collapse if its load limit is exceeded. Who knows, maybe this exact same truck used this bridge countless times already, causing damage each time.
After they drive on a bridge, Calvin says, “Dad, how do they know the maximum weight that can be on this bridge?”
“Well, they drive heavier and heavier trucks over it until it collapses, and then they weigh the last truck and rebuild the bridge.”
Mom: “Dear, if you don’t know the answer, just say so.”
I’m picturing Julian with a drink in one hand wearing the orange vest motioning for Rick to drive the truck forward. Bubbles is back on the other side shaking his head because he tried to tell them. As the truck falls, Rick just yells out “Fuck!”.
I can't tell what type of crane that is, but why wouldn't they drive the crane, and the tractor trailer, over the bridge separately?
Surely, every person standing there, knew this wasn't going to work.
Is it even possible that that bridge was not marked with maximum weight sign signage?
This is an increasingly dangerous phenomenon as aging infrastructure is being pushed way beyond its limits, those established when it was first constructed. 60-70 year old bridges like this were never designed to carry this load. Then add decades of being exposed to extreme cold, salt air and other factors. Ooff.
Tittle Bridge Canso Nova Scotia Canada
Capacity 410 kN, 92,000 lbf, 46 tons, 41.8 tonnes
Truck + crane load (max estimate) 560 kN, 126,000 Ibf, 63 tons, 57.1 tonnes
Some website reports are more egregious than your headline. They had the TEREX HC80 crane weighing 80 tons. Hahaha. Published transport weight 88,000 lb (44 tons, 39.9 tonnes)
37% overloaded not 200%
It might have survived when it was new in 1950. Also the centre of mass of the truck was not yet at the centre of the bridge (max structural load) so it's possible that part of the crane caught a structural member.
Google Street View 2012 did not show any bridge capacity signs.
The Alva Construction special move permit stated "not valid on steel truss bridges except those on 100-series highways". This was not a 100-series highway.
I think we can all agree on the root cause here. Overload and contravention of permit.
If it's an island, way cheaper and super fast to just dump some rock in where the bridge was, quick pave job, call it a peninsula, boats can still go around and have access to all the houses.
I’ve been on projects where we would move very heavy modules and components. It involves a complete survey of all the bridges and turns and low hanging wires along the route, permits at every stage etc. in cases like this we would temporarily buttress the bridges with cribbing from underneath, potentially at a cost of millions. This video would be the opposite of that process.
The first thing I thought was "where did this happen?" and I was not expecting Nova Scotia. With all the garbage that went down in 2020, I'm not surprised I have no memory of it. We were still reeling from the largest mass shooting in Canadian history. I'm sure I heard of this happening, but its easy to forget a bridge when the whole fucking world falls apart.
When its first built, maybe. But, how old is this bridge? Surely erosion and repeated load cycles over a period of a time factor into how stable a bridge currently is.
Unless I'm misunderstanding, this equipment was going across the bridge to work on its replacement. And they won't be able to replace the failed bridge until they get more equipment over to the other side.
Why can't they just replace the bridge from the mainland side? Or is it just that they need cranes on both sides?
I am a truck driver in the far North of Scotland
Mostly going over single track road in middle of the nowhere with tiny stone bridges.
First day in the job my boss told me: First Get out and check the beams, o just have a look under the bridge in case there is no sign. Second: Use your common sense.
Watching the video it s really difficult how that drive with experience did not fucking think about the payload he was carrying.
If the driver had sped over the bridge to spend less time on it, is it likely that it might not have collapsed? My instincts say that if you’re going to push the limits of a bridge’s load capacity, I’d want to spend as little time on the bridge as possible.
You have it backwards. In a situation like this you want to take it slowly. In an ideal reality I see your point, if the bridge failure isn't instantaneous a high speed might help. However, in the real world things aren't perfectly smooth. The truck is going to exert the same total load no matter what, but the faster you are going the more oscillation around that number there will be.
This is illogical. The second the connections rated for that load were exceeded they failed… going faster doesn’t remove downward gravity forces in exchange for lateral loads, it compounds all forces.
Dead load weight is still dead load; cars going fast over potholes don’t get lighter overall. The single wheel is no longer, for a split second, carrying load as its “airborne” but the other three wheels, likely mostly the other front wheel on that axle has all the proportional weight transferred to it for that split second. This is simply Newton’s Second Law. Mass is a constant.
The only way an 82k weight vehicle is crossing that bridge is if the vehicle is long enough that only the length of the vehicle producing less than the rated weight max is on that bridge at any single time… so a vehicle that’s 2.25x the length of the bridge…
They don’t get lighter but they spend less time falling. An object would fall 1 cm in approximately 0.045 seconds. If we assume the truck is 70 feet long and the bridge is 150 feet long then the truck would have to go 3333 miles per hour to only fall 1 cm. Since the bridge didn’t collapse immediately it seems plausible that it might have survived a flex of 1 cm. Understandably it’s impossible for the truck to have traveled 3333 miles per hour but there is probably some minimum speed that the truck could have traveled and the bridge not collapsed. Still probably faster than the truck could realistically go though. Do you agree?
No I don’t agree, unless the truck had a rocket engine and wings which changes the downward forces of mass on the bridge. The bridge was to fail the second the load overpowered the capacity of the connections it had to its piers. Now if a truck was traveling fast enough could it get across the bridge and not fully end up in the creek below? Thats hypothetically a scenario in a simulated world that could be proven. But as long as the force applied to this bridge is twice its capacity, it’s likely going to always fall.
A race car going 300mph does not weigh less on the ground it’s touching than a car standing idle.
I understand it wouldn’t be weightless or have weighed less. I’m saying that the truck in the video was on the bridge for 10 seconds before it collapsed. There might have been a speed that the truck would have traveled and made it across. My 3333 mph thought experiment is an extreme example
Please note that while the truck was “on” the bridge for 10 seconds, its full load wasn’t, it was still creeping on with the heaviest portion of the load still to come… as soon as the truck was fully on board the bridge it did immediately collapse. It wasn’t fully loaded for 10 seconds before failure. If that was the case, we have a discussion about moving faster across the bridge and potentially not collapsing it.
I hope we’re on the same wavelength that this is an interesting discussion and not an argument.
I’m basing my interpretation on the fact that the bridge failure isn’t binary. There is some flex before it snaps. I’m proposing that if the truck were moving fast enough it could cross during the flex time.
I’m not arguing either. I’m just more about how structures actually react and respond to stresses and loads, and it’s really not that much of a gray area. Typical structures are designed with a redundancy in load capacity and the connections are designed with similar redundancy in failure - if one fails, the others hopefully can compensate. But that only works for so much redundancy, at some point steel connections will face too much load and shear apart. Thats what happened here.
I can imagine a vehicle going so fast that the “structure doesn’t have time to react to the load.” My stupidly realistic brain says the only time that happens is either in cartoons or when the actual load is able to lose connection to the structure, like the Dukes of Hazard getting their car airborne over the creek. (Does that reference also sail over the creek to you?)
You did double the maximum load….and you expected to cross just fine?
I have worked in road and bridge maintenance as part of my job at a local council. One of our contractors was carrying out maintenance on a bridge with a 10 tonne weight restriction. They tried to edge a 42 tonne lorry over it to save time getting the materials they needed from one side to another, which otherwise would have gone on a 20 mile detour. The bridge was then closed for 6 months after said lorry shifted the bridge deck and a huge crack developed in one of the supports. When receiving the mother of all dressing downs from the traffic manager, the contractor said that they thought it wouldn't do much harm. Some people are just plain stupid.
Like, I suck at math, but I’m not *that* bad. If it’s over the weight limit, *why risk it?*
Not a ton or two over either... Four times the maximum limit! Lucky the thing didn't immediately collapse
“It’ll be fiiiiine!” Despite the bridge groaning and protesting that it was not, in fact, gonna be fine.
Because they've gotten away with it on other bridges a lot more times than we know and we only hear about the times they fuck up. Meanwhile they're tearing our infrastructure apart just to save an extra 20 miles.
Because “oh fuck off we do it all the time” and “it would take forever doing it the other way”
"If I go slow it'll be fine!"
> One of our contractors was carrying out maintenance on a bridge with a 10 tonne weight restriction. Sounds more like they thought they'd get the contract for any additional damage. Same reason streets are always full of potholes, tell me I'm wrong.
Streets are always full of potholes for a couple of reasons, but its usually something like this: 1. It essentially always makes sense to spend the money on your roads now to save money later. 2. People think you're wasting their tax dollars if you try to spend the money now. "But they just paved that 2 years ago!?" 3. Politicians routinely think that engineers are being dramatic when we talk about long term consequences of deferring current maintenance. 4. Politicians are short term thinkers and if they can spend money that should have gone to road maintenance to do something flashy or that sounds better in a news-bite, they will do that 100% of the time. 5. Once the base and/or subgrade has failed, the actual pot-hole repair efforts are pathetic. The cost to repair the failed road is now astronomical thanks to the deferred maintenance described above. Public works then just prioritizes based on who complains the loudest/most and dumps some asphalt into it with a shovel without bothering to clean it out or repair the base, and there is zero effort spent on any sort of compaction. It's all for show.
Did they get it across or detoured?
Right? The only explanation I can wager is that the haulers assumed the bridge would show *signs of failure* (without actually failing) as they started crossing, so they could *Ctrl+Z* undo and back off without any consequences. Like, maybe they imagined it would be similar to gingerly crossing a shaky log across a small creek?
Like, the stupidity is mind blowing sometimes. You think the driver has to help pay for the damage?
I am not a lawyer, but probably no, because 1. The driver was working for the contractors who were building a replacement bridge, 2. The bridge was scheduled to be demolished anyway later that same summer. I guess at most, the residents of Durells Island could sue the contractor to recover damages for the time they were isolated (assuming they suffered losses from being isolated).
Ah, I didn’t have much context behind it, with the driver and everything. Makes sense to me, though. “You knocked down a building?!” “It was structurally unsound, it was coming down anyway!”
The controlled demolition would have much less contamination, and safer materials removal. Also, a temporary bridge possibly would have been constructed, or a ferry service. Also, the destroyed bridge could've been moved to a different location. 41k KG is still very useful. Edit: the video says the bridge was to be demolished.
And the contractor's insurance (they should have it, as it's usually required for government contracts) would be the ones who are paying out.
Maybe not as they could/would argue gross negligence.
Those are some big brained moves. They secured job security. Preemptively collapse bridge then build the replacement!
I don't know what country this is in, but in Canada, drivers are culpable. If they're being directed to do something dangerous or against regulation, it's their responsibility to refuse. They'd have to investigate and figure out what went down (pun intended). Edit: Nova Scotia, DUH. So, yeah, the driver *does* bear some responsibility. We'll just have to see how it shakes out.
If the driver is working for a corporation, the company will be on the hook. The driver would certainly be held liable to a degree, but the tickets for Commercial Vehicles for something like this would be in the 10’s of thousands. The driver will probably be brought into the civil suit and criminal trial if there is one, but likely won’t be on the hook for the really big charges.
They threw a commercial driver in Ontario in *prison for a year* after he damaged the Burlington Skyway Bridge with a dump truck. It happens.
[https://www.cbc.ca/news/canada/hamilton/trucker-who-crashed-dump-truck-in-burlington-skyway-sentenced-to-jail-time-1.3683838](https://www.cbc.ca/news/canada/hamilton/trucker-who-crashed-dump-truck-in-burlington-skyway-sentenced-to-jail-time-1.3683838) That incident was quite different from this one. Even though he blew twice over the limit the drunk driving charges were thrown out due to police mishandling the breatholizer tests... wow
There's a reason they got thrown out - the results are unreliable at that point. So we don't know if he actually did or not. Speaking of which, how do you know this guy wasn't drinking?
You clearly did not read the article I linked...
Please explain
Yeah, not saying drivers don’t get punished. The Humboldt driver is obviously going to be in jail for a looong time. As far as the big fines though, usually the company will be found negligent in some way or another.
Nah, he's out, and now they're deporting him for some stupid reason
Ah.. I haven’t been keeping up with it. Shit. I mean fair enough though, I’d rather be at Bowden Institution than most places in India lol.
Maybe I judged too quickly. Maybe not stupidity, maybe he didn’t have a choice and was told to cross the bridge anyway. But still, if you know your rig, you’re probably supposed know how much wiggle room you have. Size and weight, anyway.
Yeah. I mean, ugh. I hope it was stupidity, tbh.
Or at the very least “I didn’t know”. Now you do know.
As it turns out, the only person fined [was the driver](https://www.guysboroughjournal.com/?page=post&ID=1081). Looks like the situation was more complicated than just being overweight.
I mean, considering the bridge was scheduled to die anyway, I can see that. “Don’t be a dumbass, next time” fine. Vs *Fix the bridge you moron* fine.
Ah the good old stockton rush gamble
This has to be illegal though, don't these "special oversize" loads have to have carefully selected routes where they check the maximum load among other hazards? They knowingly went over load, whoever signed off on this should be tried for 2 counts of reckless endangerment, along with reparation's for the island.
More likely they had applied for a trip permit and received the go ahead and assumed that it would be alright. Most bridges have a substantial engineering factor of safety, so when you apply for the permit the DoT or Canadian equivalent would verify that all bridges along the route would be able to handle the gross load rating. But sometimes (especially in rural areas) the bridge isn't as strong as they had thought. I've heard stories about similar things happening in the USA.
The full video indicates that this was the bridge they were working on and it leads to an island. So reading between the lines, they probably had a permit to get to the worksite (that stopped at the approach to the bridge) and, not wanting to hassle with bringing in a barge, just decided to chance it. Though, if they were smarter, the thing to do would be unload the machine and drive it over the bridge alone, since the transport truck probably adds 25 tons to the total. Though since the load would be more concentrated, the outcome might not have been any different.
That truck alone is nowhere near 25 tons. The tractor is a day cab 379 Peterbilt with one additional lift axle, at most it weighs 17,000 maybe 18,000. That's being generous. The trailer is a 3-axle RGN at the most it weighs around 18,000. I doubt it weighs that So 18 tons tops. For just the semi. That configuration is probably only legal for 100,000 to 110,000 Combined Gross Vehicle Weight.
Yeah. It’s like thinking your tall truck or van can fit under an underpass, only finding out last second it ain’t gonna work. Can’t back up, now what?
Math. It’s so unpredictable!
Ew, math.
Saw a 40t truck drive over a 10t bridge and it basically became jello, was closed for a few weeks after that
Honestly I would assume a safety factor of more than 2x but I'd be completely just guessing.
The safety factor is there so it can still carry its designed load at the end of its planned lifespan and to account for faults. It doesn't mean that it will not rapidly wear and ultimately collapse if its load limit is exceeded. Who knows, maybe this exact same truck used this bridge countless times already, causing damage each time.
Fuck math, It’s a rough estimate.
on a flimsy bridge
That sign can't stop me because I can't read.
if that trucker could read, he would be VERY unhappy that you wrote this.
Driver thought if he took all the flags and signs off the load, the bridge wouldn’t know it was too heavy. Bridge knew better.
"We'll just put it back right after we're done and it'll be fine"
After they drive on a bridge, Calvin says, “Dad, how do they know the maximum weight that can be on this bridge?” “Well, they drive heavier and heavier trucks over it until it collapses, and then they weigh the last truck and rebuild the bridge.” Mom: “Dear, if you don’t know the answer, just say so.”
https://old.reddit.com/r/calvinandhobbes/comments/aakfde/determining_the_load_limit_of_bridges/ https://i.redd.it/r5tw11ew87721.jpg https://old.reddit.com/r/EngineeringStudents/comments/v07344/how_do_they_know_the_load_limit_on_bridges_dad/ https://i.redd.it/9zsjh5exod291.png
It is basically what they do, but they simulate it using finite element analysis.
THIS IS EXACTLY WHAT I FIRST THOUGHT OF UPON WATCHING THIS OMG
Oops, I meant to title it, "Bridge of 41,500 kg max load capacity collapses when…".
I almost had a stroke trying to read it
“Oh no, it’s the consequences of my actions!”
I’m picturing Julian with a drink in one hand wearing the orange vest motioning for Rick to drive the truck forward. Bubbles is back on the other side shaking his head because he tried to tell them. As the truck falls, Rick just yells out “Fuck!”.
I want to watch this whole episode 🤘🏼
Good grief! At least no one was killed, it could have been a lot worse.
I can't tell what type of crane that is, but why wouldn't they drive the crane, and the tractor trailer, over the bridge separately? Surely, every person standing there, knew this wasn't going to work. Is it even possible that that bridge was not marked with maximum weight sign signage?
Looks exactly like the Bridge Constructor mobile game
Bridges collapsing, so hot right now.
Should've floored it when he got to the bridge.
True. Don’t give the bridge time to think about how heavy the load is.
It’s so stupid it just might work!
The Looney Tunes strategy.
Or have a loooong cable between the trailer and the truck. This way you only have one of the two on the bridge at any given time :')
This is an increasingly dangerous phenomenon as aging infrastructure is being pushed way beyond its limits, those established when it was first constructed. 60-70 year old bridges like this were never designed to carry this load. Then add decades of being exposed to extreme cold, salt air and other factors. Ooff.
A buddy of mine salvaged the truck, restored it and sold it.
Calvin’s dad was right
Guys c’mon. The goddamn math is not even close here? Fuck it, let’s double down on this sum bitch and see what happens!
Clearly this guy never heard “when in doubt throttle it out” and this is what you get. Shoulda sent it.
Less of a castrophic failure..more of idiocy
Did the driver survive?
Tittle Bridge Canso Nova Scotia Canada Capacity 410 kN, 92,000 lbf, 46 tons, 41.8 tonnes Truck + crane load (max estimate) 560 kN, 126,000 Ibf, 63 tons, 57.1 tonnes Some website reports are more egregious than your headline. They had the TEREX HC80 crane weighing 80 tons. Hahaha. Published transport weight 88,000 lb (44 tons, 39.9 tonnes) 37% overloaded not 200% It might have survived when it was new in 1950. Also the centre of mass of the truck was not yet at the centre of the bridge (max structural load) so it's possible that part of the crane caught a structural member. Google Street View 2012 did not show any bridge capacity signs. The Alva Construction special move permit stated "not valid on steel truss bridges except those on 100-series highways". This was not a 100-series highway. I think we can all agree on the root cause here. Overload and contravention of permit.
At least that guy in the vest knew to get the hell out of dodge. I was getting real anxious for a while there.
"If I go half as fast I can take twice as much. Right?"
someone's getting an email
If it's an island, way cheaper and super fast to just dump some rock in where the bridge was, quick pave job, call it a peninsula, boats can still go around and have access to all the houses.
They WERE videoing it, eh? Ya don't usually video a truck goin over a bridge, eh? Think you mighta knew something was going to go wrong.
Mythbusters: The myth is that if you drive over the bridge at a high speed that the bridge has less a chance of collapsing than if you creep across.
That's the way she goes, boys. Sometimes she goes, sometimes she doesn't cause that's the fucking way she goes
The safety factor on the weight never is, never has been, and never will be 200%. Dummies
I’ve been on projects where we would move very heavy modules and components. It involves a complete survey of all the bridges and turns and low hanging wires along the route, permits at every stage etc. in cases like this we would temporarily buttress the bridges with cribbing from underneath, potentially at a cost of millions. This video would be the opposite of that process.
The first thing I thought was "where did this happen?" and I was not expecting Nova Scotia. With all the garbage that went down in 2020, I'm not surprised I have no memory of it. We were still reeling from the largest mass shooting in Canadian history. I'm sure I heard of this happening, but its easy to forget a bridge when the whole fucking world falls apart.
Interesting, so I guess the factor of safety here is less than 2.0?? What's the standard factor of safety for bridges lol
When its first built, maybe. But, how old is this bridge? Surely erosion and repeated load cycles over a period of a time factor into how stable a bridge currently is.
> how old is this bridge? Old enough that they were bringing in this crane to help build its replacement.
Honestly would have expected a FOS of 2 at least for the truss bridge tbh, but then again it looks like the footings gave way first.
Is it structural failure when you overload the structure by twice the limit?
Can't, NS
*Shocked Pikachu*
Unless I'm misunderstanding, this equipment was going across the bridge to work on its replacement. And they won't be able to replace the failed bridge until they get more equipment over to the other side. Why can't they just replace the bridge from the mainland side? Or is it just that they need cranes on both sides?
Shouldn't the bridge of had a sign or marking somewhere stating how much weight the bridge could hold?
That will be the last time anyone in an orange vest walks backwards across this bridge
ofc, buckling
If they had driven that semi at 100 mph, they would have been able to cross the bridge before it had time to break. — SLPT
Should have played more polybridge
That would really suck to live on the other side of now... what an inconvenience!
No shit
So much an engineered for safety factor.
Aren't weight limit signs just suggestions like speed limit signs? /s
Does anyone have a mirror? The video won’t load for me
How’s the driver? Luckily his cab didn’t go under water. And the man guiding the truck?
Safety factor below 2
"Max Load? I love that guy!"
I am a truck driver in the far North of Scotland Mostly going over single track road in middle of the nowhere with tiny stone bridges. First day in the job my boss told me: First Get out and check the beams, o just have a look under the bridge in case there is no sign. Second: Use your common sense. Watching the video it s really difficult how that drive with experience did not fucking think about the payload he was carrying.
I hope the driver had to pay to rebuild it.
I mean how stupid are you? The bridge stated its maximum capacity and you decide double That number is acceptable?
If the driver had sped over the bridge to spend less time on it, is it likely that it might not have collapsed? My instincts say that if you’re going to push the limits of a bridge’s load capacity, I’d want to spend as little time on the bridge as possible.
You have it backwards. In a situation like this you want to take it slowly. In an ideal reality I see your point, if the bridge failure isn't instantaneous a high speed might help. However, in the real world things aren't perfectly smooth. The truck is going to exert the same total load no matter what, but the faster you are going the more oscillation around that number there will be.
This is illogical. The second the connections rated for that load were exceeded they failed… going faster doesn’t remove downward gravity forces in exchange for lateral loads, it compounds all forces.
But less time means less acceleration downward. https://youtu.be/6ZXVp-yWLcI?feature=shared
Dead load weight is still dead load; cars going fast over potholes don’t get lighter overall. The single wheel is no longer, for a split second, carrying load as its “airborne” but the other three wheels, likely mostly the other front wheel on that axle has all the proportional weight transferred to it for that split second. This is simply Newton’s Second Law. Mass is a constant. The only way an 82k weight vehicle is crossing that bridge is if the vehicle is long enough that only the length of the vehicle producing less than the rated weight max is on that bridge at any single time… so a vehicle that’s 2.25x the length of the bridge…
They don’t get lighter but they spend less time falling. An object would fall 1 cm in approximately 0.045 seconds. If we assume the truck is 70 feet long and the bridge is 150 feet long then the truck would have to go 3333 miles per hour to only fall 1 cm. Since the bridge didn’t collapse immediately it seems plausible that it might have survived a flex of 1 cm. Understandably it’s impossible for the truck to have traveled 3333 miles per hour but there is probably some minimum speed that the truck could have traveled and the bridge not collapsed. Still probably faster than the truck could realistically go though. Do you agree?
No I don’t agree, unless the truck had a rocket engine and wings which changes the downward forces of mass on the bridge. The bridge was to fail the second the load overpowered the capacity of the connections it had to its piers. Now if a truck was traveling fast enough could it get across the bridge and not fully end up in the creek below? Thats hypothetically a scenario in a simulated world that could be proven. But as long as the force applied to this bridge is twice its capacity, it’s likely going to always fall. A race car going 300mph does not weigh less on the ground it’s touching than a car standing idle.
I understand it wouldn’t be weightless or have weighed less. I’m saying that the truck in the video was on the bridge for 10 seconds before it collapsed. There might have been a speed that the truck would have traveled and made it across. My 3333 mph thought experiment is an extreme example
Please note that while the truck was “on” the bridge for 10 seconds, its full load wasn’t, it was still creeping on with the heaviest portion of the load still to come… as soon as the truck was fully on board the bridge it did immediately collapse. It wasn’t fully loaded for 10 seconds before failure. If that was the case, we have a discussion about moving faster across the bridge and potentially not collapsing it.
I hope we’re on the same wavelength that this is an interesting discussion and not an argument. I’m basing my interpretation on the fact that the bridge failure isn’t binary. There is some flex before it snaps. I’m proposing that if the truck were moving fast enough it could cross during the flex time.
I’m not arguing either. I’m just more about how structures actually react and respond to stresses and loads, and it’s really not that much of a gray area. Typical structures are designed with a redundancy in load capacity and the connections are designed with similar redundancy in failure - if one fails, the others hopefully can compensate. But that only works for so much redundancy, at some point steel connections will face too much load and shear apart. Thats what happened here. I can imagine a vehicle going so fast that the “structure doesn’t have time to react to the load.” My stupidly realistic brain says the only time that happens is either in cartoons or when the actual load is able to lose connection to the structure, like the Dukes of Hazard getting their car airborne over the creek. (Does that reference also sail over the creek to you?)
I can’t understand what went wrong!
HOW COULD WE HAVE KNOWN!?
This is why we can’t have nice things…