Crane lifting dozer and capsizing

[Scrub Puller]

Yair . . . bigshow I never would have thought of that. Is the weight of cable a consideration when calculating lifts?

1-2 lbs. per foot adds up quick.

Puts me in mind of a major design stuff up with a large high speed catamaran project . . . somehow the designers missed the fact that, in operation, many tons of water were flowing through the jets.

Cheers.

 

[OldandWorn]

1-2 lbs. per foot adds up quick on what looks like an 8 part set-up.

I think you nailed it bigshow. That weight is also being subtracted from the rig. Talk about being on the edge.

 

[bigshow]

While manufacturers charts vary, generally speaking, everything beyond the boom point is considered a deduction from the maximum allowable gross weight for a given set-up. The load chart will instruct you as to what deductions need to made for that particular crane and how it is set-up. Outrigger position, jib set-up, rooster sheaves, auxiliary hoists, parts and length of line, there are LOTS of variables that can get you in trouble if not taken into the equation.

 

[Silveroddo]

The weight of the cable crossed my mind right away but I dismissed it, didnt catch that it was rigged as 8 parts. How big of a crane is that? 8 parts would make it good for roughly 130k wouldnt it?

 

[Blmreject]

I just watched it again, i thought i remembered him swinging across the wall. I think it went over to fast for it to be line weight. He must have boomed down a little for it to turn over that quickly, but i wasn't there.

 

[Shenandoah]

I just watched it again, i thought i remembered him swinging across the wall. I think it went over to fast for it to be line weight. He must have boomed down a little for it to turn over that quickly, but i wasn't there.

Once the outriggers raise off the ground the boom tip will increase the radius quite a bit by falling forward. Exponentially.

 

[Jim D]

trying to think about this for a second, if the dozer couldn't drive down into the hole that it was needed in, what's the point in dropping it into the hole? what could it do down there?

I kknow that dozers work underground in mines. But the vid looked like a daylight building site. I'm a tyro here, but what could a dozer do in the bottom of that hole?

 

[td25c]

I had the same question as Jim D . What was the dozers job in the hole? Did they realy need that big of a dozer for the job? Kind of looks like a bridge job but cant realy tell. One thing that would have saved them if they were dead set on using that dozer and crane would have been to remove the blade from the dozer and do it in two lifts.Blade assembly is pretty heavy on that size dozer,but also can be removed pretty easily.

 

[bigshow]

Looks like they are rehabbing a canal, as there is scaffolding that the camera person is on and across the canal is some more, also the air hoses and exposed rebar lead me to believe some demolition is going on of some sort. Maybe they were putting that dozer down there for some grading of the floor. As far as 8 parts is concerned, it looks that like it is reeved for 8, but that is my speculation. As far as line pull, I don't know what the winch on that rig is good for, perhaps they wanted a slower line output, who knows if they even had enough wraps on that juicer to even reach the bottom. I wasn't there but watched the video a few times out of curiousity as I am not one to bash an operator in a situation that I know nothing about.

 

[.RC.]

trying to think about this for a second, if the dozer couldn't drive down into the hole that it was needed in, what's the point in dropping it into the hole? what could it do down there?

I have seen pictures of high rise building projects where by D9's are lifted into the foundation hole for the building to rip up the ground for excavation... drilling and blasting cannot be done as it is a built up area and not do the foundations of nearby building much good...

 

[rare ss]

all our lifts are max 85% capacity od the crane on the lift plan, can see why now.. thats a top video showing a crane maxed out, rekon the guys are on the mark about the rope being enough to lift it off the outriggers and the increase in radius as the thing tipped was enough to make it a sure thing

20t crane and 20t dozer? should work.... right?? lol

 

[cutting edge]

He got the crawler in the hole at least. That's what he was there to do. :lol:

 

[Sirius]

I'm not an operator but a tech for a Grove/National/Manitowoc dealer and for their load charts at least, you do not have to factor in line weight as long as you are using that line pull. More simply put, if your load requires 5 parts of line and you have 7 reeved, then you must do the deductions for that extra line that you don't need.

I've done stability tests on a few national boom trucks ranging from 8t to 45t. That's 18% over chart and I've never had one lift off as quickly as in this video. Either he was well over chart to begin with or caught up on something and bounced the load. Mind you we are only going to tip as far as the test weight is off the ground, this guy has no where to drop the load.

Lifting over an outrigger in theory should give you more stability, however whenever I swing over an outrigger during stability tests its almost 99% certain that the opposite outrigger is light or off the ground. Straight over the back has always been the most planted for me because of the added counterweight of the truck. In some of the new cranes coming through our place, I've noticed National for example has added an over the back chart on the 55t that automatically kicks in on the LMI as soon as it sees you swung over the back or within the 2 rear outriggers and adds to your max capacity.

 

[heavylift]

playing line out does two things, adds weight to the load. Plus it takes weight off the back of the crane, Kinda like removing a counterweight.
Still probably not that great of amount, but little too much can be a lot.

The crane also lost 200+ pounds, when the operator jumped

 

[FirstEliminator]

As an amatuer/novice crane operator (meaning I simply bought a crane for personal use and don't do this for a living) I learn a lot from watching these videos and reading all the comments from experienced operators. I'm scared half to death about having an accident. This motivates me to learn as much as I can and be aware of as much as I can. Operating a crane is definitely NOT the type of activity where you want to "learn by making mistakes". I'd much rather learn from someone else's mistakes and learn from reading ahead.
Thank you-- to the experienced who share their knowledge. I believe this free information has more than once already helped somebody avoid the type of mistake that would make the news.

appreciative thanks,
Mark
Berkshire Transmissions
North Adams, Massachusetts

 

[gostr8r]

In regards to your line down question, a load of that size on a crane that small would require many parts of line, so even if he was at full throttle and full stroke the load wouldn’t be going down very fast. Many hydros can’t take a rated load in the high speed mode anyhow. I think he was nervous as hell, used too low of an rpm, which for a hydro isn’t really a good thing, and then when he took it out too far it was doomed to bring the crane with it to the bottom. Poor planning, maybe an undersized crane, soft o/r ground support on the side he was lifting from, poor set up and some bad operating decisions once he had it in the air. Without knowing the truth or details any or all could be the cause, but an official investigation will bring the facts to us soon.

What i don't get is why he was lining down so slow. If you know you're way out of chart, get after it! Get that thing over the edge and line down for all your worth. He held that thing there for ever, he could have had two feet off the ground by the time he started going over then it wouldn't have mattered.

I don't condone running crane that way, but every crane hand has a few stories to tell. Also why in the heck would go over chart heading away from you, especially heading down a hole. you are powerless in that situation. Always give yourself an out.

 

[No1Hookman]

No matter how much maintenance is performed, a grossly overloaded crane will fail. I don't think lack of service had anything to do with that accident. But physics did.

 

[Oxbow]

I'm not a crane guy either, but years ago I worked for a fellow that had a 35 ton squirt boom Loraine, and a newer 45 ton squirt boom Grove. The Loraine gained much of it's capacity by virtue of weight, while the Grove was more leverage, ie. it wasn't proportionally as heavy as the Loraine, but the outriggers went out considerably farther. With the Loraine, you could have your off side outriggers come off the ground and still be able to function. With the Grove, once the off side outriggers came off the ground it went over quickly (the guy I worked for found out the hard way.

Probably wouldn't have made much difference with the distance of drop it had for the dozer, but there is a destinct difference in the way the two of them handled.

The guy in the video needed an old lattice boom with brakes on the hoist that he could have just let it go if he were quick enough.

 

[IronworkerFXR]

Its that bad chain of events that get's you in the end, it was just not one thing but a plethora of such.

guess somebody should turn off the air compressor to.

Mr OSHA would have a field day there.