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Toppled Crane
- Thread starter pswag115
- Start date
there is some stuff on the trailer as to what I can't tell ....
I'll guess a Liebherr crane... if it is I don't think all the counterweight is on the machine...
The guess to boom angle is somewhere in the 40% area... This crane may have all the bells and whistles, but as someone said shockloading several tons .... well you see the results... no b&w can stop that...
I did find a chart and a rough guess capacity. 6.0 unknown if the chart was in tons or thousands of pounds....
well there's my 2 cents
The last crane I seen around here like that. the outriggers had pushed thru the asphalt. NO crane pads
I'll guess a Liebherr crane... if it is I don't think all the counterweight is on the machine...
The guess to boom angle is somewhere in the 40% area... This crane may have all the bells and whistles, but as someone said shockloading several tons .... well you see the results... no b&w can stop that...
I did find a chart and a rough guess capacity. 6.0 unknown if the chart was in tons or thousands of pounds....
well there's my 2 cents
The last crane I seen around here like that. the outriggers had pushed thru the asphalt. NO crane pads
They messed up big time heaveylift.It takes three simi trailers to haul the counter wieghts & rigging for a crane job like that.Allot easyer to get a climber & hack that tree down to size so it can can be hauled out & chipped.
special tool
Senior Member
This thread blows my mind.
Why didn't they get a climber is right. This must be some guy putting on a show.....crane owner or operator is homeowner's uncle or brother....one of those deals - HAS to be, right???
Like I've said before many times - some guys have NO business being around ANY machine - you can't unlearn stupid.
Why didn't they get a climber is right. This must be some guy putting on a show.....crane owner or operator is homeowner's uncle or brother....one of those deals - HAS to be, right???
Like I've said before many times - some guys have NO business being around ANY machine - you can't unlearn stupid.
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tonka
Senior Member
25c is right, i would cut/split it and used for BBQing red oak = good BBQ!
AtlasRob
Senior Member
The wood butchers site ( cant spell arborist, whatever one of those is )sing the praises of the company doing the chopping, dont seem to be your average cowboy outfit but somebody most certainly got it wrong.
Operator didnt have a chance, being blind.
It also states there were bodies in the tree, quite understandable really seeing the size of the bit still standing, unless they were on the head of a giraffe which I cant see from any of the pics.
It seems that the bit being removed......suddenly twisted, DOH! would that be as the cut was finished Einstein.
Would suggest to me that for 1 the slinger was not experienced enough and 2 the cutter was greedy, probably both and the same looking at the outcome. The bit on the ground looks to have several good bow stumps and I can imagine it being very difficult to judge the balace point, so take smaller bites, It will be quicker in the long run I promise you.
Operator didnt have a chance, being blind.
It also states there were bodies in the tree, quite understandable really seeing the size of the bit still standing, unless they were on the head of a giraffe which I cant see from any of the pics.
It seems that the bit being removed......suddenly twisted, DOH! would that be as the cut was finished Einstein.
Would suggest to me that for 1 the slinger was not experienced enough and 2 the cutter was greedy, probably both and the same looking at the outcome. The bit on the ground looks to have several good bow stumps and I can imagine it being very difficult to judge the balace point, so take smaller bites, It will be quicker in the long run I promise you.
special tool
Senior Member
The wood butchers site ( cant spell arborist, whatever one of those is )sing the praises of the company doing the chopping, dont seem to be your average cowboy outfit but somebody most certainly got it wrong.
Operator didnt have a chance, being blind.
It also states there were bodies in the tree, quite understandable really seeing the size of the bit still standing, unless they were on the head of a giraffe which I cant see from any of the pics.
It seems that the bit being removed......suddenly twisted, DOH! would that be as the cut was finished Einstein.
Would suggest to me that for 1 the slinger was not experienced enough and 2 the cutter was greedy, probably both and the same looking at the outcome. The bit on the ground looks to have several good bow stumps and I can imagine it being very difficult to judge the balace point, so take smaller bites, It will be quicker in the long run I promise you.
I like your approach to this thread - let's try examine the pathology of the team of fools who got that job done.
Anyone else have a clue what could possibly have transpired here?
I'm sticking with a family showoff.
special tool
Senior Member
Also an excellent point - hadn't thought about that.
HHHHHHHHHHHHHHHHHHHHMMMMMMMMMMMMMMM....
I wonder NOW how will they try to remove the tree??
Maybe with this thing?
What do you think, Powerjoke?
Attachments
tonka
Senior Member
:beatsmewell that does eat dozers or breakast so a little tree shouldnt be a problem...LOL!
'Look ma, no hands!'
I have a feeling his insurance rates just went up a couple hundred percent, thats if he is lucky enough to still be insured. What a mess!
rbtree
Member
True. My opinion about what happened:
I'm an arborist. I've been practicing for 35 years. done a fair bit of crane assisted work. Some good posts here, but some not so, even a few that sound like they've come from crane operators.
It's obvious, to anyone who looked at all 24 photos up on the newspaper website, that the tree crew had some degree of competence. This was a huge spreading tree.
However, some questions and possible explanations as to why
One, why was the jib installed? Greatly reduces the load chart. Certainly it would have been better to have had the boom fully extended (It isn't) than to have the jib on.
Two, why weren't the full complement of counterweights installed? In one of the photos, it looks like there's more on the flatbed. If so, they appear to be doing a good job of holding it down. Possible reason--the tree company is paying for the crane with its lower rating, to save money.
Assuming this is a Grove 5175, with the amount of counterweights installed, the load chart shows its good for about 6200 lb. not exact, as the boom isn't fully extended, but the jib is on.
That means trouble....as I've estimated the log that caused the failure to weigh between 5000 and 8000 lb.
Which brings us to the next problem, and that is how the climber made the cut. If one looks at the log in the street, and the way it appears in the tree, one can see what the top of it is showing, which is how the climber made the cut that was just above it. He made a mismatch cut, but on the bottom side instead of the top (the side away from the crane, and perhaps away from its lean. This is a guess, as it may have leaned away from the crane, in which case the cut may have been correct.
Anyhow, my point is, with sections that aren't vertical, they should be picked toward vertical, gently, till the center of balance is directly under the slings. Then, the section can be gingerly picked off, reducing shock loading to a minimum. Best ways to do this, when there's concern about the weight being close to the max is either peel the log, with one cut, starting from the side the weight is on. Alternatively, a face cut can be made on the opposite side.
(There's a different method for lateral picks, which involves two slings to balance the load, and picking it horizontally.)
Continuing, the log on the ground out front is the last pick made before the collapse. It is larger diameter, but straight, and was closer to the operator. Therefore, on the failed pick, the boom was at a lower angle, and further away. And the load wasn't vertical. So, it should have been cut as I described, and slowly lboomed up to vertical, which would have brought the boom and load closer to the centerpin, thus increasing lift capabilities.
Since the reports state there was shock loading, I think the cutter made those same improper mismatch cuts, and the full weight came onto the cable as the butt fell off. In an instant, the dynamic forces on the system would have spiked up. Just a guess, but assume the piece was 20 degrees off vertical. If the heavier butt fell off, and it fell/swung two-four feet, the dynamic loading could have easily doubled--or worse. This force is hard to figure, but know this: A free falling 5000 lb object onto a fixed cable will apply 10,000 lb to the system after falling 1 foot, and 15,000 after two feet!
Mistakes, as I see them:
Improper cut
Jib on
Not enough counterweights.
Crane operator may have had too little tension on the load.(I'm guessing this is wrong, as they'd already done 95% of the tree, without incident, and he should've had a good feel for the weights.)
AtlasRob
Senior Member
Welcome aboard rbtree and thank you for a very good insight into the potential problems from somebody who has been there and done it.
liebherr1160
Senior Member
One, why was the jib installed? Greatly reduces the load chart. Certainly it would have been better to have had the boom fully extended (It isn't) than to have the jib on.
The jib chart will beat the full on main boom chart in many cranes most often when reaching.
Not to mention the height in the beginning..
Two, why weren't the full complement of counterweights installed? In one of the photos, it looks like there's more on the flatbed. If so, they appear to be doing a good job of holding it down. Possible reason--the tree company is paying for the crane with its lower rating, to save money.
Its often done in crane rental a larger crane rented out as a lower capacity unit..
The counter weight configuration would allow a compareable chart ..
A 175T unit ..with a change of counter weight and compared to say a 100 T unit can be equaled or a little better than a 100T unit..
Example
Grove GMK 4100B (100Ton)
Max Counterweight 42,500lbs----167ft main boom @80ft radius = 11,800lbs Capacity
Grove GMK 5165-2 (165T)
(possable 88,400lbs CW)
46,000lbs counter weight installed
166.4ft main moom @80ft radius 17,800lb capacity.
Grove GMK 5275 (275)
(Possable 112,400 lbs CW)
46,200Lbs CW installed
164 ft main @ 80 ft radius 23,000lbs Capacity..
So you can see how a unit can be made into a smaller unit by just playing with the aplicable counter weight configuration's
No not the tree company getting cheap ..there may have been a job for the smaller units where that crane would not have fit ..there was a generous amount of room at that site where the 175 was ..So the company played the charts an sent the crane (175) out the gate as a smaller unit..and its done everyday ..there are applicable charts for lesser than maximum counter weight on all these european cranes ..Its part of what makes them versitile and popular in the crane rental scene
That 175 as its quoted ,,my best assumption was rented out as a 80-90t unit.And a company sales rep must have visited the site prior to the crane showing up ...Really a guy just dosent take a call for a tree falling over the phone and send out the crane before taking a look ..there's alot to consider when sending a crane into a residential area ..
Assuming this is a Grove 5175, with the amount of counterweights installed, the load chart shows its good for about 6200 lb. not exact, as the boom isn't fully extended, but the jib is on.
That means trouble....as I've estimated the log that caused the failure to weigh between 5000 and 8000 lb.
I say your incorrect ..pending somebody with the Grove Charts coming on and telling me im incorrect
the jib was on Intially for height and reach..still at the end it was on for reach ..the head of the boom is only 10-20 feet past the stump.From what I remember of the Grove charts on this ..the section left back with the jib on is a legitimate chart. the jib will offer a slightly better capacity on the reach over main boom with that counterweight..
There will be a difference between the two charts ..jib and main
But now after being down that road myself ..alot of clients will be obliged to take smaller pieces than have that pinned boom scoped in ,jib stowed and then squirt back out ..for what the sake of the time it takes to make a couple of extra cuts ..leave it on ..your talking 45minutes to turn that around to full on main boom ..for whats gained ..make a couple of smaller pieces ..
45 minutes for everyman on the crew ..you got 6 men say ..that dont have a whole lot to do ..and a crane going Ka-Ching-Ka-Ching on the money..it adds up..alot of money ..keep the guys moving make a few extra cuts ..usally what the response to me is ..
Mistakes, as I see them:
Improper cut
Jib on
Not enough counterweights.
Crane operator may have had too little tension on the load.(I'm guessing this is wrong, as they'd already done 95% of the tree, without incident, and he should've had a good feel for the weights.)
The extra counterweight ..may have ment the boom would have buckled ..ALL the European AT' cranes are soully based on the structual strenght of materials ..
You said it your self ..the cuts are wrong ..I'm willing to bet that the operator had pulled the quoted weight ..and then the saw got to binding up and had to let it down a little for the cutter to get it out and carry on ..from another direction ..then the wholesystem broke down and procedure went out the window
Not to mention where the log started to roll ..the delay in cranes computer system which can be .5-2seconds before it actually starts to react to the operator's input and then ramp up ..didnt make the situation any better ..
Thanks for coming out ...Look forward to a tree guy's perspective ..:drinkup
The jib chart will beat the full on main boom chart in many cranes most often when reaching.
Not to mention the height in the beginning..
Two, why weren't the full complement of counterweights installed? In one of the photos, it looks like there's more on the flatbed. If so, they appear to be doing a good job of holding it down. Possible reason--the tree company is paying for the crane with its lower rating, to save money.
Its often done in crane rental a larger crane rented out as a lower capacity unit..
The counter weight configuration would allow a compareable chart ..
A 175T unit ..with a change of counter weight and compared to say a 100 T unit can be equaled or a little better than a 100T unit..
Example
Grove GMK 4100B (100Ton)
Max Counterweight 42,500lbs----167ft main boom @80ft radius = 11,800lbs Capacity
Grove GMK 5165-2 (165T)
(possable 88,400lbs CW)
46,000lbs counter weight installed
166.4ft main moom @80ft radius 17,800lb capacity.
Grove GMK 5275 (275)
(Possable 112,400 lbs CW)
46,200Lbs CW installed
164 ft main @ 80 ft radius 23,000lbs Capacity..
So you can see how a unit can be made into a smaller unit by just playing with the aplicable counter weight configuration's
No not the tree company getting cheap ..there may have been a job for the smaller units where that crane would not have fit ..there was a generous amount of room at that site where the 175 was ..So the company played the charts an sent the crane (175) out the gate as a smaller unit..and its done everyday ..there are applicable charts for lesser than maximum counter weight on all these european cranes ..Its part of what makes them versitile and popular in the crane rental scene
That 175 as its quoted ,,my best assumption was rented out as a 80-90t unit.And a company sales rep must have visited the site prior to the crane showing up ...Really a guy just dosent take a call for a tree falling over the phone and send out the crane before taking a look ..there's alot to consider when sending a crane into a residential area ..
Assuming this is a Grove 5175, with the amount of counterweights installed, the load chart shows its good for about 6200 lb. not exact, as the boom isn't fully extended, but the jib is on.
That means trouble....as I've estimated the log that caused the failure to weigh between 5000 and 8000 lb.
I say your incorrect ..pending somebody with the Grove Charts coming on and telling me im incorrect
the jib was on Intially for height and reach..still at the end it was on for reach ..the head of the boom is only 10-20 feet past the stump.From what I remember of the Grove charts on this ..the section left back with the jib on is a legitimate chart. the jib will offer a slightly better capacity on the reach over main boom with that counterweight..
There will be a difference between the two charts ..jib and main
But now after being down that road myself ..alot of clients will be obliged to take smaller pieces than have that pinned boom scoped in ,jib stowed and then squirt back out ..for what the sake of the time it takes to make a couple of extra cuts ..leave it on ..your talking 45minutes to turn that around to full on main boom ..for whats gained ..make a couple of smaller pieces ..
45 minutes for everyman on the crew ..you got 6 men say ..that dont have a whole lot to do ..and a crane going Ka-Ching-Ka-Ching on the money..it adds up..alot of money ..keep the guys moving make a few extra cuts ..usally what the response to me is ..
Mistakes, as I see them:
Improper cut
Jib on
Not enough counterweights.
Crane operator may have had too little tension on the load.(I'm guessing this is wrong, as they'd already done 95% of the tree, without incident, and he should've had a good feel for the weights.)
The extra counterweight ..may have ment the boom would have buckled ..ALL the European AT' cranes are soully based on the structual strenght of materials ..
You said it your self ..the cuts are wrong ..I'm willing to bet that the operator had pulled the quoted weight ..and then the saw got to binding up and had to let it down a little for the cutter to get it out and carry on ..from another direction ..then the wholesystem broke down and procedure went out the window
Not to mention where the log started to roll ..the delay in cranes computer system which can be .5-2seconds before it actually starts to react to the operator's input and then ramp up ..didnt make the situation any better ..
Thanks for coming out ...Look forward to a tree guy's perspective ..:drinkup
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rbtree
Member
Thanks, liebherr....
You know a lot more than cranes than I, but I know trees. Based on what you said (and I understand the pricing and how to pay for a lower rated crane by not using the full CW complement), the main mistake was the way the climber made his cut. I explained the proper way, which most likely would have been fine.
The piece that was cut may even be less than 6000 lb, as it doesn't look huge. (You should see some of the picks I do with my favorite guy, who only has a 23 ton truck mount. As long as we're close, we pick 5000-10,000 lb with it routinely (vertical picks, no dynamic loading)
Here's the relevant load chart. I think page 10 0r 11 may be close...but maybe there's a better page showing the jib.....
http://www.maximcrane.com/loadcharts/4 All Terrain Cranes/Grove/GMK-5175_175T.pdf
I think I know why it might be better to not have full boom extension, but to fly the jib....Is it because it's lighter?
You know a lot more than cranes than I, but I know trees. Based on what you said (and I understand the pricing and how to pay for a lower rated crane by not using the full CW complement), the main mistake was the way the climber made his cut. I explained the proper way, which most likely would have been fine.
The piece that was cut may even be less than 6000 lb, as it doesn't look huge. (You should see some of the picks I do with my favorite guy, who only has a 23 ton truck mount. As long as we're close, we pick 5000-10,000 lb with it routinely (vertical picks, no dynamic loading)
Here's the relevant load chart. I think page 10 0r 11 may be close...but maybe there's a better page showing the jib.....
http://www.maximcrane.com/loadcharts/4 All Terrain Cranes/Grove/GMK-5175_175T.pdf
I think I know why it might be better to not have full boom extension, but to fly the jib....Is it because it's lighter?
rbtree
Member
Some of our work;
This huge pine was about 90 feet from centerpin, if I recall. Crane was an old 120, but brought no counterweights. (We'd decided on a 90 ton, but they were out on jobs)
This pick is a 40-50 foot long limb that we balanced with two slings. It prolly weighed 4500 lb....
This huge pine was about 90 feet from centerpin, if I recall. Crane was an old 120, but brought no counterweights. (We'd decided on a 90 ton, but they were out on jobs)
This pick is a 40-50 foot long limb that we balanced with two slings. It prolly weighed 4500 lb....
rbtree
Member
I guess I can't edit messages here? I'm trying to figure out how to embed pics on this forum. Anyhow, if I can't, just click the link. Or maybe someone can clue me in.
[image]http://farm2.static.flickr.com/1036/1366881070_53621e5307_o.jpg[/image]
rbtree
Member
Away she goes.
http://farm2.static.flickr.com/1197/1366880954_c95762945b_o.jpg
The weight on this one was close to max. The operator perhaps could have had the ball slightly off dead vertical and closer in before the cut was started. Then, he might no have had to boom up to gently maneuver the section free. Cabling up might have been sufficient. It's been a couple years, but I recall it was delicate. Johnny had trouble freeing the saw. This may have been a situation where two opposing chokers 180 degrees offset may have been better. Not sure, but the main problem was the need to boom up to bring the load closer to the centerpin.
http://farm2.static.flickr.com/1401/1365988527_d7d1af7458_o.jpg
http://farm2.static.flickr.com/1197/1366880954_c95762945b_o.jpg
The weight on this one was close to max. The operator perhaps could have had the ball slightly off dead vertical and closer in before the cut was started. Then, he might no have had to boom up to gently maneuver the section free. Cabling up might have been sufficient. It's been a couple years, but I recall it was delicate. Johnny had trouble freeing the saw. This may have been a situation where two opposing chokers 180 degrees offset may have been better. Not sure, but the main problem was the need to boom up to bring the load closer to the centerpin.
http://farm2.static.flickr.com/1401/1365988527_d7d1af7458_o.jpg
rbtree
Member
After that, the tree got a lot larger, but we only had a few more picks to do, as we left a wildlife snag at about 15 feet.
Shorter picks:
That's my 22 lb Husqvarna 3120, that's been modded, and with close to 13 horsepower, pulls its 42" bar with ease.
Shorter picks:
That's my 22 lb Husqvarna 3120, that's been modded, and with close to 13 horsepower, pulls its 42" bar with ease.