I am an electrical contractor in Garden City Kansas and do alot of work with the company responcible for the pictures. Luckly no one was hurt in the accident (it makes it alot more interesting to hear the stories). The driver in the incident is still employed in the same position, though he now ducks when ever he goes under and overpass. ha ha.

The solution is intuitively obvious and left as an exercise to the reader.

Like my sister the EE said; "Mechanical engineers design weapons. Civil engineers design TARGETS!"

E=1/2 m V^2; only needed a little more to slice on through!

Picture is realistic but genius cameraman made the trick. Using your engineering backround to respond with sophisticated engineering language makes you a fool. Sorry just kidding.

The Driver belived in the consistancy of a positive result thru the assumption of a negative attitude

It is disgraceful that obvious Civil Engineers are pontificating over this issue. Unfortunately gentlemen this is an aero/me crossover problem and requires sophisticated analysis of adiabatic air flow principles as found in Ascher Shapiro advanced fundamnetals of air flow

This analysis revolves around the fundamentals of lift itself 1/2 pv2 A.

Analysis as follows: The tractor was traveling at 62.5 mph this basic calculation is the impulse of the tractor and its backhoe being absorbed by the friction coeficcient of steel on concrete a widely know factor of 20 slugs per inches per inch t.

Added factor as the backhoe progressed down the highway the inverted bucket caused down force on the tractor trailer lowering its height but more importantly causing the bucket itself to press downward. As the tractor approached the overpass the down force was blocked by the bridge causing the loss of airflow over the buchet(inverted) and thus lift not downforce was created causing the bucket to smash upward through the bottom of the bridge abutement. The delay in airflow is the reason why the bucket popped up AFTER the tractor was under the bridge missing the guardrails.

the author is a mechanical/aero major and a lawyer so this must be correct Dick Engel

He wasn't going fast enough. He did not make it clear through.

Cool. I will have to send this over to Greg May over at Two Sockets Two Meters. He though that Bob Badgers' photo of water gushing out of a meter socket was cool too.

There are 2 military words for this.

SNAFU: Situation Naturally All F-worded Up

FUBAR: Definition 1. F-worded Up Beyond All Repair First used during World War 2 to decribe close encounters of the wrong kind with bullets, land mines, torpedoes, knives, hand grenades and so forth.

Definition 2: F-worded Up Beyond All Recognition First used during World War 2 to describe what happens to a frequency shift keyed short wave radioteletypewriter signal when the ionosphere is doing the samba.

I also found a color printer over at Marc's, brand new with USB port and everything else for under $10. Was virtually a steal.

Mike Cole mc5w at earthlink dot net

Is the calculation supposed to be based on assumption that the bridge is American made and the backhoe is Japanese? How would you like to have a car made by the backhoe maker?

Yes, I ahve the answer,

E=MC2

Truck's speed easily calculated merely by applying The Evolute of Retrograde Phase Disposition, and dividing by Charmondelly's Grillage Coefficient--there--you have it--Warp 9.

As an engineer with graduate degrees and Licenses in several States I must say that this sort of problem is not taught in school very often (at least not in the ones I attended) and is not tested for very often in State licensing exams (at least not in the ones I practice). Furthermore, I don't think that either overpass design standards or those covering backhoes considered this possibility.

As interesting to me is how this came about. Heinz R.

Also have to condider the resistance of the hydraulics as it appears the bridge pulled the boom arm backwards. The question I have did the chain binders continued to hold hoe onto the trailer?

what the hell was he or she thinking.

78 MPH - Damage was greater due to bridge design with the lower portion being a hollow pocket, much like larger overpasses. This design is common to prolong and reduce icing on bridges in winter. It appears that the truck made it through, with enough power to break free of the trailer. The truck should have come to a complete stop in apporximately 35 sec. at 75 feet.

What the heck does the tractor look like and did the driver go through the windshield.

I would be more worried what my insurance rates would do than how fast it was going. That will take some real arithmetic. Sure am glad it is that guy that has to explain this one.

1 NO AMOUNT OF SPEED WOULD DO IT THE BOOM WOULD RIPOFF.

2 NO SUCH THING AS 1 1/2 rebar #18=1 3/8 BRIDGE REBAR IS #6 3/4

3 this boom actualy punched up thrue the bridge deck and stopped although since the boom pivits , it let the rig trailer go about 10 ft.

Look at the first picture...... if it really sliced through the bridge, then wouldn't the slice go all the way through? (top to bottom) The slice is only made through the bottom part of the bridge. the top half is still there. and not even cracked. this is evident on both side of the bridge too. So the question is what really happened to get the arm through the bridge.

Snopes says the driver was not injured and also not cleared to be on that road. The construction company is responsible for the $134k cost of fixing it.

http://www.snopes.com/photos/accident/hoecrash.asp

I'm surprised it's that cheap to fix a hole that big? Ah, another article says the $134k was the cleanup cost and the replacement cost will be a lot more. This article also names the driver and explains how he came to make the mistake.

http://www.equipmentworld.com/apps/news/articleeqw.asp?id=52814

Here's what happened: The boom of the trackhoe struck the first main beam of the bridge below the deck and handrail. As it moved throught the bridge, the boom was pulled upward and over-extended the rams which failed either in the rams or brackets holding them on. Then when the boom hit the center main beam of the bridge it stopped and tipped the trackhoe up, breaking any binders or chains that held it, and smashing the cab into the bottom of the bridge (note damage to bridge at bottom trailing edge, and trackhoe cab). The track hoe was then wedged up against the bridge and the step in the low boy trailer (this was not a flat bed as stated). The remaining momentum apparently caused the trailer to fail at the goose neck or tounge as you can see the back end of the trailer in the photo, but not the tounge. To cut throught the bridge completely, you would need bind the hoe to the trailer with something stronger and reinforce the trailer tounge to withstand the forces imposed by the bridge. But the bridge was apparently strong enough to cause 3 other components to fail first: the rams, the binders, and the trailer. The boom was the one component that looks like it could have cut through the bridge if it could have been held securly by the others that failed.

This actually happened in Lousiana during hurricane Katrina.

The backhoe was on site to shore up the levy which is just out of camera range.

You mean after airplanes into buildings, they resorted to backhoes into bridges? Scaling down ha! I still insist that the big three should hire the backhoe maker to produce some safe cars.

I would say that the rig was moving at about 74 M>P>H>. It had to be some kind of a school trained driver , because most old driver know better.We have too many young driver that just don"t care>>>>>>>>>>

How much will he be fined and what is the ratio of the fine to the taxpayer cost to repair the bridge?

I don't have an answer on the speed, but whatever tiedowns they used to keep the backhoe on the trailer, buy them.

The fastening of this backhoe to the trailer must have been done by the maintenance manager over at the American Seaway Foods division of Giant Eagle over in Bedford Heights, Ohio.

This past Tuesday he told me that I was "too smart" read ( snotty voice ) Too Expensive for his company. One of the complaints that I made to the Ohio Construction Industry Licensing Board's assistant Attorny General is that nobody is making industrial electricians get licenses and nobody is making factories hire journeymen through licensed electrical ontractors.

Since 1979 the emphasis has been on hiring the dumbest people that can be found on the basis that dumb is cheaper.

This is yet another reason, why siblings should not procreate with one another.

Did no one here actually attend an engineering college? Where you had to actually SHOW YOUR WORK on homework?

If we're just going to be throwing numbers around... he'd have to be going 119 MPH (simply because that was my average speed the last time I fell out of a plane).

Did anyone call FEMA ? I am sure our goverment would pay all the residences south of the bridge lodging expenses until the bridge is fixed. Of course this would be after an extensive 6 month Army corp of engineers survey. Followed by 4-6 months of Minority or Women owned business RFPs.

I have read all the posts and agree with those that state that LEVERAGE was responsible for the severe damage. The hoe did not "cut" through the bridge, since it is clear that the guardrails are intact on both sides. The hinge point between the boom and stick (hoe terminology) caught on the bridge, and just like a chain boomer the forward momentum forced the arm up beyond what mere potential energy from speed would normally do. By the way, a track hoe has tracks like a bulldozer and pivots 360 degrees. A backhoe is typically on a loader tractor-type affair and only pivots 180 degrees. I also disagree with the statement that the hoe is toast. A new arm and cab and it is good to go. I'm still wondering about that pucker factor though!! NL

If you invert the picture, it just looks like a Mexican demolition crew hard at work?

How about the tension on the chains & attachments.

It\'s a trac-hoe not a backhoe. This would be a great advertising promo for the trac-hoe company--it takes a licking and keeps on digging. And not a scratch on the trac-hoe.

Is the rebar made in USA or China?

Best estimate, 82 MPH. The only reason it did not make it all the way through the bridge is due to the resisitive forces created by the hydraulic cylinders of the shovel arm. Had the the fluid not slowed him down, I think he would have made it.

Contributing factors, Interstate highway in Kansas. Flat terrain, not much traffic.

Thanks Mike for sending this.

78 plus or minus .0265% MPH.

"Robert M. Glidewell" wrote:

what happened to the truck? can you post more pitures?

That trakhoe is done,

The digging arm is bend over backward, telling me that the mounts for the arm have either been stressed beyond limits, or the cylinder mounts have broken. or both.

The trailer is broken, the gooseneck attatch points have pulled out.

It's interesting to me that the 'hoe didn't flip over backward.

What's the compressive strength of the concrete?

Did the driver fiddle with the governed speed of the tractor?

inquiring mids want to know.

There are no overpasses in Kansas.

Mike, believe it or not, this is a common, almost daily event here on Long Island, NY. It is so common that these events make no news reports, no comments, no pictures, but many traffic delays of humongeous proportions. (You may have a preferred alternate spelling of my last adjective).

Why is this so? Decades ago Long Island was "blessed" with the building of a large system of parkways to facilitate getting to our very nice beaches. In order to keep out the "undesireables" (which was a euphemism for New York City people) from arriving by bus, the many bridges were built very low with clearance only for cars or small trucks. Today, these parkways are all integrated into modern highways and this creates almost an infinite number of ways for large trucks to wander on to the parkways. When they do, a bridge strike is assured every time.

Our esteemed local government rises to the occassion by doing what?----Of course, put up SIGNS!! That will fix everything. Problem is, they are all in English. Now I ask you: How many truck drivers read English, compadre? Or, how many believe the signs? After all, who would be stupid enough to build low bridges on a main road?

I have witnessed this carnage for over 60 years. But they are thinking about the problem, so be patient.

Yes, I am serious. None of this is exagerated.

1. Hyundai is one tough machine. 2. Dont drive over bridges in Kansas. 3. Did some of the contractors that worked on the Big Dig come from Kansas?

The fault lie withe the Driver, If he was going approx. 97 MPH he would have slice all the way through. Also it is hard to tell if he had enough tie down holding the rig on the trailer.

Looking at the huge dent in the underside of the bridge above the operator's cab, it looks like the machine REALLY wanted to flip over, but didn't have the clearance. Also, the bridge's concrete guardrail isn't broken. I'd hate to have been driving near this fella when he hit the bridge...or crossing over the bridge!!!

This is why a GFCI device should be mounted in all vehicles between the seat and the steering wheel.

Considering the mass of both the truck and the piece of equipment the speed limit would do the trick. If the driver survived the impact he most likely has crushed ribs and a broken face, along with various internal injurys. Larry

The bridge could not be sliced in half. It was the force created by the bucket being hit first and then the energy created allowed the arm to project through the deck and asphalt of the bridge( weakest part). if the arm was raised and moving at 80-100mph the loader's arm would simply snap off or be ripped from the trailer because it would not allow for the loader to be compressed under the bridge, as what happened to allow the arm to project through the deck. nice pictures though.

Guessing 70 - 75 mph, no brake application & a severe headache for the driver stressing about loss or ticketing, etc.

I am sure that hitting an overpass is as bad as hitting an overhead power line - an electrifying experience for the driver...

Would have been much cleaner with a light saber.

Fast enough and this had to be built with the lowest bid?

According to my calculations one would need to be traveling 64.7% faster than the sample case pictured. To bad there were no video of the actual event. This guy didn't make it through. He just wasn't trying. THANKS FOR LIGHTENING THE DAY!

Where's the sign indicating, "CROSS UNDER OVERPASS AT YOUR OWN RISK"? I smell a lawsuit in the air.

I don't have a clue about any of this. Way over my head.

Q:1 the truck can't go fast enough to make the arm go through the bridge

Q:2 about a1/4 of a mile

Report has it that the driver was last seen eastbound through Missouri, still holding the steering wheel, with a rather surprised look on his face....

Answer 1 - The geek in me says 79 miles per hour based on approximate mass and force.

Answer 2 - The smarta$$ in me says "faster than that guy was goin" cause he didn't make it all the way through.

If they would have had AFCI protection, this would have never happened. Hmmmm!

This is actual proof that what we have believed all our lives is false, scissors do cut rocks.

Inquiring minds also want to know:

1) What the heck is the difference between a "track hoe" and a back hoe? 2) Why the heck was the boom facing forward rather than the usual rearward.

Answer to speed question: Not necessarily all that fast. at all. With the boom facing forward it could have easily scissored (jackknifed) upward after initial contact with the first or second girder. Then inertia and leverage would pull the boom up poking it thru the bridge deck. Once the original cut is made, the answer to the extra credit problem is given. Namely it took only about half of the width of the bridge for a complete standing stop. You can't ignore friction on this one since both shearing and friction energy are expended by the boom while substantial friction energy is exerted by the flat bed trailer undercarriage in sliding and eroding the road bed beneath the bridge. Ditto for the drivers side tractor tread.

I also agree that the hydraulic cylinder or links were busted early on.

BTW, I think that the back hoe (track hoe) very nearly wound up wearing the bridge.

Inquiring minds further want to know what does a new overpass cost these days.

P.S.: The above analysis is the result of a rather long E-mail thread among a group of engineers that analyzed this thing to death a few weeks ago.

Best regards . . .

Jim

Don't forget to figure in "Pucker Power" when solving for time and distance to stop. I bet the driver had to remove his shorts with a crowbar

He hit it while the concrete was still plastic then they took off the forms for effect.

I do not believe that this could penetrate cured concrete like this. Impossible. The trac-hoe would flip right off the carrier backwards.