JLG near disaster

[willie59]

Ok, this doesn't look good.
I wanted to post this to point out to anyone out there that uses aerial lifts; these machines have limitations. To push one beyond the designed capabilities of one is extremely dangerous, and somethimes deadly. Only God knows how this operator escaped serious injury or death.





Got a call from a customer about a JLG 80HX+6 that came off a grade in an "out of control" manner. When I arrived on the site, it didn't take me long to sort out what happened. Near the bottom of the grade, it appears the operator released the drive controller, which would have applied the brakes. That's when the left drive wheel brake engaged, but the right drive wheel continued rolling. This is a two wheel drive machine, so it only has two brakes. With one wheel not braking, there's no way only one wheel can hold a near 37,000 lb (16,783 kg) machine. So the left drive wheel began to skid the tire, and it left a long skid mark which indicated the machine was traveling at a fair clip. I'd wager the operator did not come off this hill in high drive, but rather in low, yet the machine did not hold back in low speed and began moving with excessive speed. When the left wheel finally braked at the bottom of the driveway, by now the operator had no real control. That's when the right wheels ran off into large rip rap rocks. I'm certain that man basket began bouncing the operator violently, I'd say he was gripping the handrails with all the strength he had, unable to let go and steer the machine, hoping and praying the machine would come to a stop.

Given the right drive wheel did not apply brake, I started checking there. Found the planetary hub components good. Removed covers of drive motor, found oil, yet no failed hoses. Something going on in there.





Upon removal of drive motor, found motor shaft seal blown outward,indicating excessive internal pressure on the seal which typically means a failed motor. Here's a pic of the motor shaft, you can see the portion of seal pushed out on the shaft.





When I first arrived at the machine, I tried to operate the drives. It didn't even put any hyd load on the engine. Once I removed the right drive motor and capped those hyd lines, tried drive again using left drive motor, still no load on engine. Removed the left drive motor, capped the hyd lines to motor, tried drive again. Now the engine went under load and opened drive circuit relief valve. So the machine had both drive motors failed. Then how did it move you ask? Probably, the left drive motor was already dead and machine was only moving using right drive motor. No way an operator would know this. So he would have come off this grade with only the right motor holding back the
machine. With such pressure on one motor, boom! Seal blows out, fills the dry brake assembly with oil, and now the motor has no hold back power. The brake is now well lubricated, so it can't perform it's task to help stop the machine. This thing was an accident waiting to happen, and it's probably all as a result of the customer using this machine to go up and down hills that the machine is simply not designed to do putting excessive stress on the machine components. You must respect and heed the working
limitations given by the manufacturer with these machines, or you'll put your self and co-workers in a perilous situation.

Here's a video clip I made while on site. Sorry about the poor video quality. My
Blackberry appears to have issues in video mode.


YouTube - ‪Stuck JLG‬‎

 

[barklee]

WOW!! Its a wonder the guy driving that wasnt ejected or the lift isnt laying upside down! I never understood why they ever built a 80' lift two wheel drive. JLG has to know that people do really dumb crap with these machines and only having two brakes on a machine that big just wont cut it. Although the operator should have known better. I have said for some time now that there should be more and better training involved when it comes to aerial equipment. People dont understand how a machine works so they dont think about the stresses and loads they are putting on a machine when they do things that are "pushing" the envelope. They view the equipment like a car in that if the machine will do a particular task than it must have been designed to do that. Just like having a JLG 135' lift fully extended and driving it, just because the machine will let you doesnt make it a good idea!!!!!!!!!!!!!!! They shouldnt rent aerials without having a license on file, or at least a card that shows training was provided by an "approved" instructor.
All i can say is, thank God no one was hurt and your lift only has some blown seals!!!!!! Good post, i like the way you illistrated this from begining to end.

 

[JDOFMEMI]

So many ways that could have been worse. Glad it was just the motors, not a fatality to go with it.

As already stated, training would be a good thing. Too bad it is so hard to initiate such a change. There would be lots of resistance, and cries of the added cost, but think of the savings in injuries, deaths, and machine damage.

 

[Tiny]

I have seen these machines abused in every manor that man can think of I believe. They are suppose to be a safer way to work at heights . The kick in the pants to me is,If this is how they treated it on this job what else has happened to it?? Would you want to trust your life to this machine ??

 

[digger242j]

...it appears the operator released the drive controller...

I just want to point something out (at the risk of looking like I have some sort of superior attitude, which is not my intention.)

You use the word "operator", when in reality, it was probably a carpenter, or roofer, or painter. Manlifts aren't "operator's" machines in the same sense that earthmoving equipment or trucks might be. The machine's purpose is to get the guy to where he does the work, as opposed to most machinery, where the machine does the work, as guided by the operator.

Probably most manlift operators aren't as tuned in to the nuances of how the machine is performing, or what it can or should be expected to do, because they're not "operators", they're carpenters or roofers or painters. This guy probably never had a clue that something wasn't right with the machine until it got away from him.

 

[surfer-joe]

JLG's are disasters!

 

[willie59]

You use the word "operator", when in reality, it was probably a carpenter, or roofer, or painter.

Sorry digger, just terminology habit of mine...vehicles require drivers, machines require operators.

But, you are absolutely right. A manlift is just as likely to be operated by an experienced construction worker as it is a home handy man on the weekend. That is the very reason I wanted to post this incident, for everyone who reads this on this forum to be mindful of what you are doing with these machines. This particular time, the operator is very fortunate he wasn't on the evening news. :yup

I will add this about manlifts for the sake of clarity. Although they are a machine that lifts a person up to heights, and any such machine can be inherently dangerous, they are actually a particularly safe machine for perfoming this task by design. Think about it, just how often do you hear the news of a manlift tipping or failing. It does happen, but not that often. And typically, it's not because of a failure of the manlift, but rather, as in this case, the operator doing something with the machine it is not, was not designed to do. A poorly maintained machine, or one operated with faulty components, could always be a potential accident laying in wait, but even then, it would be inconsistent with proper operation of a manlift. Proper procedure requires constant inspection of the machine, along with a thorough annual inspection. Anyone who uses a manlift for months on end without giving it a look over, or a small business painter/carpenter that owns one and never checks the machine, is engaging in risky behavior. These things are built with sufficient stuctural competence and component durablilty to perfom their task with minimal failures that would cause harm to the operator. They are even tough enough to handle a little abuse and neglect, but that would be bad practice on the part of the person who is depending on this machine to raise them in the air and keep them there. And for someone who is going to operate a manlift and not study/understand the do's and do not's of operating these machines is potentially putting their own life in peril.

As for this particular incident, it's true the operator may have had no way of knowing the drive motors were going down which was a pending risk when going down that hill, but it's his fault for taking it down a hill that is steeper than what the manufacturer recommends, risky behaviour. Moreover, concerning this particular machine, there was an experienced tech, me, that was on this site about a year ago to perform an electrical repair to their machine. At that time I warned the owner of the machine and all his workers there at the time to be very very careful going up or down the grades around this site. And I strongly recommended having another machine tied off to it when on these grades. Flat out told them I, personally, would not take that machine up or down these hills without assistance of another capable machine. The man is fortunate he is still breathing air from not heeding my warning.

Be careful and safe operating machines folks. Everyday you get to go home and eat supper is a good day.

 

[willie59]

JLG's are disasters!

I beg to disagree with ya joe. Unless you could provide documentation to support your claim. Then, I would be more than willing to yield to you.

 

[digger242j]

...As for this particular incident, it's true the operator may have had no way of knowing the drive motors were going down...

But my point is that an operator may have had that feeling in the seat of the pants or the pit of the stomach that something wasn't right, because operators are tuned in to their machines. The trades that need 37,000 lbs of glorified stepladder, eh, maybe not so much.

(Well, some operators are tuned in to the machine. Lord knows we've seen enough "You'll never believe what that meathead did to this machine!!" threads, and we're sure to see some more. But you get my drift...)

 

[willie59]

But my point is that an operator may have had that feeling in the seat of the pants or the pit of the stomach that something wasn't right, because operators are tuned in to their machines. The trades that need 37,000 lbs of glorified stepladder, eh, maybe not so much.

(Well, some operators are tuned in to the machine. Lord knows we've seen enough "You'll never believe what that meathead did to this machine!!" threads, and we're sure to see some more. But you get my drift...)

Ain't that the truth!

 

[OFF]

Great video Atcoequip!!

having a downhill "runaway" with an 80ft lift has got to be a life changing experience for the guy in the basket.

They've come a long way in making aeriel lifts "fool proof" over the years but still. I'd say at least 90% of the manlift calls I get are operator error or caused by operator error. And they always blame it on the machine.

 

[oldhousehugger]

Be careful what you ask for. As soon as they make the manlift perfectly "safe" and "foolproof" it may be almost useless. It would be like trying to make a chainsaw safe. If you make a chainsaw "safe" they would have to have instructions on how to NOT start it and how to Not pick it up and how to Operate it only without a chain.
If you make a tool completely idiot proof, it usually means destroying its original purpose.
The majority of plane crashes are caused by pilot error and they are supposed to have taken the class.
I would also like to say that more and more we find lately that the jobs like carpenters, roofers and painters are being occupied by folks who do not speak English and may not be able to read or write their native language. These folks are hired by unscrupulous contractors at below market wages and given minimal supervision. I have heard many a story about guys falling off a roof, breaking a leg and they don't even go to the doctor because they are afraid of being caught.
30 years ago we used to be careful about having proper safety harnesses and tested and labeled extension cords. OSHA used to check stuff like that. I can’t remember the last time I have seen an OSHA inspector; certainly not here in Texas the right to work state.

 

[FSERVICE]

great pics ATCO!!!
was this lift a rental or was it a customer owned unit?? did the operator have any trainging??

 

[willie59]

great pics ATCO!!!
was this lift a rental or was it a customer owned unit?? did the operator have any trainging??

It was a customer owned unit. As for training, not sure, but I can say this, about a year before this incident, they called me to this site to repair an electrical problem on the machine. When I arrived at this site , the owner of the machine was there and workers that were with him at that time and told them that this machine is not designed for the grades on this jobsite, and furthermore, that I, personally, would not take that machine up or down any of these grades unless there was another appropriate machine tied to it. I guess they didn't heed my warning. :nono I'm really surprised the operator didn't get injured, or worse, end up on the 6:00 news.

 

[Benbuilt4u]

lucky it didnt flip on its side!