Dammmmn!

F1nut

https://www.foxnews.com/auto/dump-truck-hits-bridge-6-feet

motorstereo

Wow; I'm guessing it's either a crappy bridge or one hell of a trailer dump. Having seen first hand my share of dumb truck driver moves I'm betting it's the former and Georgia needs some better bridge inspectors.

msg

Wow.
How does a guy not realize the bed is raised?
Can you imagine his reaction when it got his attention?

maxward

Maybe the only things holding the bridge to the abutments were gravity and friction.

Jstas

msg wrote: »

Wow.
How does a guy not realize the bed is raised?
Can you imagine his reaction when it got his attention?

Depending on the type of hydraulic system, a seal failure in the right spot can raise a dump body without any interaction from the driver. There's typically safety features in place to stop it from happening but sometimes those safety features can fail too.

As far as not noticing, it's possible. You'd think wind resistance and such would make a noticeable difference but those tractors are so powerful that they can easily overcome the drag caused by the dump body being in the air.

Why the bridge moved, I dunno, doesn't seem like it should have but nationally there is an 80,000 pound weight limit on federally maintained roads. Some states have mostly state and local roads and they have different weight ratings on those. They will allow 120,000 to 150,000 pound weight limits on those roads. Mostly in places like Michigan, Wisconsin or Minnesota where logging trucks can easily exceed NHTSA weight ratings or in places like Montana or the Dakotas with mining traffic. It's not uncommon to see "road trains" with 2 or 3 trailers hauling 20K-30K pounds each. With a tractor weighing in at about 30-35K pounds, a two trailer train with 60K pounds on it has a total weight of about 90-95K pounds.

Pulling that kind of weight down the road at highway speeds requires more than a significant amount of torque.

But that's a 40 foot dump body in the pictures, it will hold 60K+ pounds of stuff all by itself so it i's pretty stout. But, the bogeys and trailer frame are missing so the tractor and the rest of the trailer probably kept on going unless the impact was hard enough to snap the trailer pin in the clamp too. Then the trailer frame is off in the woods somewhere and hopefully the tractor is on the side of the road.

One thing I know for sure, that driver's log book is being gone over with a fine tooth comb and he was taken from the scene to a local hospital for a evaluation and a drug test.

scubalab

Bridges are designed to move, longitudinally (direction of traffic ON the bridge), typically at one end of each span. A single span bridge will have a fixed end and an expansion end. You'd be surprised how much a bridge will expand and contract (dependent on the length of span and the temperature differential) throughout the year. I've seen expansion dams open upwards of 4-5 inches in winter months. But 6 feet, transverse - WOW. Helluva force at impact! F=MxV ---> Heavy truck, highway speeds = insane impact force. I can't say I'm surprised, or that the bridge was structurally deficient. This bridge moved at the expansion end of the span. Basically, each beam is (was) 'resting' on a pot bearing (by design) that allows it to expand and contract at that abutment. It looks like the beams were knocked off the bearings and slid along the beam seat at the abutment.

Jstas

OK, going with scubalab's post, your average "tractor trailer" on U.S. highways is going to run about 80K pounds loaded.

Unloaded, about 40K pounds.

Assuming a velocity of about 88 feet per second for about a 60 MPH traveling speed, that gets you an impact force for a loaded, 80K pound vehicle of about 218,809.87 pound feet of force.

That truck was unloaded, it seems, though so we'll assume ~40K pounds and that's still just under 110,000 pound feet of force (F = 109404.93514117 lbf for the actual calculated value)

For comparison, your average inattentive suburban soccer mom missile, the Toyota Camry. A top of the line, fully loaded Camry weighs in at about 3595 pounds. If the Camry were to impact that span at about 60 MPH like the trucks above, at 88 feet per second, that Camry is going to hit that bridge span with about 9,832.77 lbf of force or about 1/10th of the force that the unloaded tractor trailer would impart and 1/20th of what a loaded tractor trailer would impart.

But at 110K to 220K pound feet of force, that is an immense amount of force to hit anything with.

pitdogg2

Wonder what the steering wheel/seat belt bruise on the drivers chest looks like

motorstereo

I still say crappy bridge design. The company I used to work had drivers that used to hit overpasses with excavators or bodies they had forgotten to put down and I've never seen damage to a bridge like that. Most of the time there was barely a scratch on the bridge. One particular driver a few years ago hustling down the highway for his next load had forgotten to put the body down on his triaxle. He went through the windshield when the body dislodged and the truck continued on running him over him and killing him instantly. The truck was destroyed but the bridge suffered very little damage.
Even the drivers can't understand how someone can drive down the road with the body raised as there's alarms going off, light coming in the back window where it's normally dark and of course the handling has to be different.

Nesmith98

Better hope they had good insurance. Rebuilding a bridge could be in the millions.
Something like this happened in my neck of the woods but it was one of those big green signs over top of the expressway.

scubalab

Sorry - I misspoke/mis-typed. I meant momentum. Momentum is mass times velocity. It’s Friday and my brain already started the weekend!

The difference with this impact was that it caught the fascia beam AND the parapet. I thought I read that the truck was loaded (with tractor tires). There’s also a good chance it was loaded to the max, if not overloaded. So, it’s safe to assume that the truck was pushing 80,000 lbs. that equates to over 7 million lb-ft/sec of momentum! Most other bridge impacts are just the beam (which would have taken some of the force by buckling). Also, I’ve seen many impacts with Tri-axles (again - lower impact point on the bridge and about half the weight since the bed would be empty if the bed was raised) or equipment on a lowboy. In that case the momentum would be just the weight of the equipment being hauled and it typically just hits the beam.

I’m not saying the bridge was in tip-top shape, but they simply are not designed to take that type of impact.

Regardless, this is crazy, and lucky nobody was killed.

tophatjohnny

James Brown no doubt

jdjohn

pitdogg2 wrote: »

Wonder what the steering wheel/seat belt bruise on the drivers chest looks like

...and his underwear. He probably needed a fresh pair of drawers after that

mrbigbluelight

I think that we just need to re-imagine bridge and overpass construction. 🙄

Jstas

motorstereo wrote: »

Even the drivers can't understand how someone can drive down the road with the body raised as there's alarms going off, light coming in the back window where it's normally dark and of course the handling has to be different.

I used to repair trucks and heavy equipment like this. They get abused excessively and alarms can fail as much as the equipment can. One corroded wire connection and no buzzer, light or bell will ring. We had to check every safety feature every time a truck hit a service interval. Safety devices were the 2nd most repaired thing on the trucks right behind lights and just ahead of brakes. Additionally, in trucks like this where there's perpetually a body blocking any rear view, our drivers often had stuff covering the rear window like jackets being hung up, cardboard for colder months to generate more heat in the cab or sometimes to just block sun coming in and beating down on their neck.

So yeah, it is entirely possible that somebody might not notice. Especially if they were excessively tired or under the influence of something like an upper or drunk/stoned out of their gourd.

motorstereo

Jstas wrote: »

motorstereo wrote: »

Even the drivers can't understand how someone can drive down the road with the body raised as there's alarms going off, light coming in the back window where it's normally dark and of course the handling has to be different.

I used to repair trucks and heavy equipment like this. They get abused excessively and alarms can fail as much as the equipment can. One corroded wire connection and no buzzer, light or bell will ring. We had to check every safety feature every time a truck hit a service interval. Safety devices were the 2nd most repaired thing on the trucks right behind lights and just ahead of brakes. Additionally, in trucks like this where there's perpetually a body blocking any rear view, our drivers often had stuff covering the rear window like jackets being hung up, cardboard for colder months to generate more heat in the cab or sometimes to just block sun coming in and beating down on their neck.

So yeah, it is entirely possible that somebody might not notice. Especially if they were excessively tired or under the influence of something like an upper or drunk/stoned out of their gourd.

Since this happened in Georgia I find it doubtful there was a coat hanging over the back window but anything is possible I guess.....so then ok to all of those but.........the driver can't hear that noisy pto running???

Jstas

It doesn't get cold in Georgia?

They don't require construction crews to be wearing protective and/or high visibility vests/jackets when on site?

Whatever, dude, Believe what you want.

Also, if you've ridden or driven a truck like that you'd know how loud a PTO drive isn't compared to the road noise. But the PTO doesn't necessarily have to be engaged for the dump body to be up while driving down the road. If wind from the road gets under the dump body and the check valve that prevents the cylinders from expanding fails then just driving down the road could pick the dump body up and there's no hydraulic pressure to keep the dump body down because it's all leaking through the broken check valve.

Then again, depending on what kind of PTO it is, there's a chance that the PTO engaged itself because of a worn clutch or bearing causing enough drag for the pump to pump fluid despite being disengaged. At high way speeds and engine RPMs, a small leak in the PTO system could build significant pressure over a number of miles.

BlueBirdMusic

Another bridge wreck on Wednesday afternoon on I-75 north of Atlanta.




A tractor-trailer crash damaged a bridge and shut down I-75 South in Bartow County for three hours Wednesday afternoon.

A FedEx truck pulling two trailers was traveling south just before 1 p.m. Wednesday when it drove into the median and plummeted to Joe Stella Drive, a road that runs beneath the interstate, according to the Georgia State Patrol.

The truck burst into flames, causing visible damage to the bridge, GSP said in a statement.

Photos from the scene show the wreck beneath the interstate and damage to the guardrails along the bridge. Traffic was restored in all southbound lanes nearly three hours after the crash, according to the Georgia Department of Transportation.

audioluvr

Crap! Well that package is going to be delayed.

motorstereo

Jstas wrote: »

It doesn't get cold in Georgia?

They don't require construction crews to be wearing protective and/or high visibility vests/jackets when on site?

Whatever, dude, Believe what you want.

Also, if you've ridden or driven a truck like that you'd know how loud a PTO drive isn't compared to the road noise. But the PTO doesn't necessarily have to be engaged for the dump body to be up while driving down the road. If wind from the road gets under the dump body and the check valve that prevents the cylinders from expanding fails then just driving down the road could pick the dump body up and there's no hydraulic pressure to keep the dump body down because it's all leaking through the broken check valve.

Then again, depending on what kind of PTO it is, there's a chance that the PTO engaged itself because of a worn clutch or bearing causing enough drag for the pump to pump fluid despite being disengaged. At high way speeds and engine RPMs, a small leak in the PTO system could build significant pressure over a number of miles.

Ok then lets say you're correct in all those assumptions as well as having a deaf driver. Now how does one explain the driver not noticing the impaired handling of the truck with the body raised? I've been around dump trucks for the past 40 years and I do know that they teeter totter with the body up and not to mention the wind resistance of the barn door sized body. FWIW I ain't buying any of the excuses mentioned thus far.

Jstas

Whatever

nooshinjohn

motorstereo wrote: »

Jstas wrote: »

It doesn't get cold in Georgia?

They don't require construction crews to be wearing protective and/or high visibility vests/jackets when on site?

Whatever, dude, Believe what you want.

Also, if you've ridden or driven a truck like that you'd know how loud a PTO drive isn't compared to the road noise. But the PTO doesn't necessarily have to be engaged for the dump body to be up while driving down the road. If wind from the road gets under the dump body and the check valve that prevents the cylinders from expanding fails then just driving down the road could pick the dump body up and there's no hydraulic pressure to keep the dump body down because it's all leaking through the broken check valve.

Then again, depending on what kind of PTO it is, there's a chance that the PTO engaged itself because of a worn clutch or bearing causing enough drag for the pump to pump fluid despite being disengaged. At high way speeds and engine RPMs, a small leak in the PTO system could build significant pressure over a number of miles.

Ok then lets say you're correct in all those assumptions as well as having a deaf driver. Now how does one explain the driver not noticing the impaired handling of the truck with the body raised? I've been around dump trucks for the past 40 years and I do know that they teeter totter with the body up and not to mention the wind resistance of the barn door sized body. FWIW I ain't buying any of the excuses mentioned thus far.

My stepdad was an HEO for Ramsey County MN for 40 years. There is no way whatsoever to not feel that there is something wrong. Inexperience, operator stupidity and distracted operation are the only plausible explanations. A couple hundred pounds of material stuck to the top of the cab shield is enough to pull a GMC 5-Star over on her side, and twist the frame enough to total the truck. The shaking in the cab alone would be enough to let you know there was a problem.