Toppled Crane

You can bet your bottom dollar there is a lot of finger pointing going on.

Whether the investigation will come to any other conclusion than the one we all have ( its too big and too heavy at that radius ) will be intresting to see.

Either that or the insurance adjusters will make history and say lets have a :drinkup and sort this out between us. The expression " dont hold your breath " springs to mind

I found this interesting little bit of info ..ANSI z133.1/5.7.7
www.sherrilltree.com/site/pdfs/Log_WeightChart.pdf

Its a green log weight chart..If everyone involved with the tree falling had one including the operator ..with the climber including a tape measure ..and the piece was estimated according to the chart ..how can anyone be blamed ?..

I have conversed with a couple arborist ... the chart is great ..however it doesn't compensate for the season and type of weather experienced ..some have said there can be as much as a 40% difference given the season and weather experienced ..such as a wet winter and wet spring ..early summer the tree will be allot wetter and heavier ..but by how much is anyone's guess ..and the determination can often be left to the arborist what to expect in reality ..

so in the end if this chart was followed and the cutter did his thing and it came in allot heavier ..OSHA should inquire as to the who's what's and where's ..this chart came to be ...and I'm suspecting allot of revision's to the chart if it is indeed found to be unacceptably inaccurate..

the 12,000 lb weight reported ..I'm wondering if its a gross weight with the block and rigging ..not the tare weight ..Its not unreasonable for the media to embellish a story a little and may have taken the first weight that was heard when it landed ...
I agree with other's when OSHA collects evidence such as a load ..a certified weight will have to be obtained to have it hold up in court ..

That operator will be looking for work in a different state....or a different trade. CCO will pull his certification if he is found at fault.

Impact said:

This may be in the wrong section, if so, My apologies. Reading liebherr's post about his procedures for setting his outriggers coincides with outrigger pads I've just fabricated for a 50 ton Grove AT crane.

I've got a set of 6' square wooden pads. They work great, but are overkill for most jobs, and are so heavy a forklift is needed to set them. We still use typical wood blocks, but lots of times the wood blocks STILL won't support the load. These shop/home built pads are 42" square. Each one has a 3/16" plate top and bottom. Inside I used 2" wide flat steel turned on edge welded on 16" centers similar to a fifth wheel plate on semi trailers. Dead in the center is a clevis mount to lift them with the crane. The clevis will fold over inside a 6" sch 40 pipe. All four pads will set on a rack that the crane can pick up and set on the back of the truck. Anxious to give them a try and see how it works.

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Love the mats ...kinda sends a message to the client to ...we're here ..and we mean it !

Steel on steel is rather slippery ..dont forget to have a few bits of plywood for each one ..we're still required to have wood under the outrigger pad ...no-where does it say it cant be steel re-enforced wood..

Also the hole in the middle for the lifting lug could lead to an argument that the outrigger pan is being bridged...I know those Grove pads are rated at 45T load baring capacity , might be nice to have a shovel on hand to fill that void with dirt should an argument arise

For cranes like those you have ..50 ton onto 110 ton .. we use some 4x4x 2" thick steel plates ..with 4 lugs each, with a lead on each one to allow each plate to be neatly packed one on the other .. again with 3/4 ply-wood on top..

On the larger units ..greater than 110 and on ..we use 8'x9'x 8" steel mats ..constructed out of 8' -1015-H-beam (1/2-5/8) web ,full penetration weld and end capped with 1/2 steel plate, 4 lugs each,each with a lead to allow easier and neater packing ..3/4 plywood on the top ..the whole stack is about 12,000lbs (4-mats)..And they are used every time we set it up ..religiously ..without fail ...get allot of looks when they get laid out ...


Leave them black ..I'd paint the circle hot pink ..but hey :beatsme..etch your name in them ..

liebherr1160 said:

Love the mats ...kinda sends a message to the client to ...we're here ..and we mean it !

Steel on steel is rather slippery ..dont forget to have a few bits of plywood for each one ..we're still required to have wood under the outrigger pad ...no-where does it say it cant be steel re-enforced wood..

Also the hole in the middle for the lifting lug could lead to an argument that the outrigger pan is being bridged...I know those Grove pads are rated at 45T load baring capacity , might be nice to have a shovel on hand to fill that void with dirt should an argument arise

For cranes like those you have ..50 ton onto 110 ton .. we use some 4x4x 2" thick steel plates ..with 4 lugs each, with a lead on each one to allow each plate to be neatly packed one on the other .. again with 3/4 ply-wood on top..

On the larger units ..greater than 110 and on ..we use 8'x9'x 8" steel mats ..constructed out of 8' -1015-H-beam (1/2-5/8) web ,full penetration weld and end capped with 1/2 steel plate, 4 lugs each,each with a lead to allow easier and neater packing ..3/4 plywood on the top ..the whole stack is about 12,000lbs (4-mats)..And they are used every time we set it up ..religiously ..without fail ...get allot of looks when they get laid out ...


Leave them black ..I'd paint the circle hot pink ..but hey :beatsme..etch your name in them ..

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I appreciate the post. I can see steel on steel as slippery..BUT..what does it matter? I mean..I guess I can see if it's not level an outrigger could slid. Wouldn't be much trouble to add a 3/4" plywood to the top right now.

Seems almost every crane failure I see is outrigger punching through. Good idea to RELIGIOUSLY use the mats. I'm still amazed at the number of cranes that turn over w/o a load on them. I've been reading some of your old posts the last few days. Seems you know your business. Welcome back..

Impact said:

I appreciate the post. I can see steel on steel as slippery..BUT..what does it matter? I mean..I guess I can see if it's not level an outrigger could slid. Wouldn't be much trouble to add a 3/4" plywood to the top right now.

Seems almost every crane failure I see is outrigger punching through. Good idea to RELIGIOUSLY use the mats. I'm still amazed at the number of cranes that turn over w/o a load on them. I've been reading some of your old posts the last few days. Seems you know your business. Welcome back..

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I did machinery moving for a bunch of years before cranes .. the Iron workers and millwrights explained it to me like this ."steel on steel has a low co-effecient of friction which is why the wood is used ...think of it as brake-lining .."
It could be 1/4 inch really with those mats you made ..as long as its wood ..
3/4 Is what we used ..mainly because its usally the same thickness thats in abundace in the scrap heap on some job's ..:drinkup

We were left with no choice on the mats ..its all we had other than 4x6 dunnage..in the end its alot better than slugging wood any day of the week ...also ..the mats were all ordered up the same ..because its easier to get extra to double them ..and everything bigger than a 110 up to 650T was set on the larger mats ...
Crane failure's ..most days a crane is only as good as whats under the pad's ..which is pretty much everyday ..

Impact said:

I appreciate the post. I can see steel on steel as slippery..BUT..what does it matter? I mean..I guess I can see if it's not level an outrigger could slide.

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Even on level ground and crane leveled. If you have steel outrigger (or aluminum alloy) pad sitting on a steel cribbing pad, if the operator was under full swing and had to come to an abrupt stop, you could slip all the outriggers off the pads.

Like Liebherr said, wood (thick or thin) is like a brake lining for the pads.

And your correct; always use some form of cribbing and always crib proper.

Instead of dirt... which could turn to mud ... then freeze...
make wooden plugs to fit the holes.... Painted hot pink
The paint also would help when the crane sets stored for long periods... no rust stains running down the crane...

I worked several places that have steel on top of railroad ties... I never thought of it as being slick but I know it is.. just from carrying stuff on forks...

I think the wood is a good idea....

Hi liebheer.... glad to see you back....

Its interesting to me that they would send a crane out for one tree. Not being familiar with the pricing of cranes I figured I would ask what you guys would estimate they charged to take out a tree of that size. Around here in my area I would guess from looking at the pics that you could have that tree dropped and hauled to the street for around $1000. Its just hard to see how they could justify the expense of having a crane. Someone please educate me on this :beatsme

Yea I was thinking the same thing.

I think the tree was over the house... they didn't want to damage the roof by dropping a tree on it....
which was a success... but the crane did some damage....
If you look at the photos there is a lot of sawdust on the roof... and a crane dent

Blue 02 TJ said:

Its interesting to me that they would send a crane out for one tree. Not being familiar with the pricing of cranes I figured ..................... Its just hard to see how they could justify the expense of having a crane. Someone please educate me on this :beatsme

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I have come to the conclusion that the felling company would provide a quote to the customer, based on their experience of chopping little bits off and lowering them by hand / winch / pully at X $ a man per day x a crew of 4 or 5 men for a good few days = Y. Against a crane for a minimum hire and the job done in a shift with two men. What they forgot was the mathmatician to do the calculations.

Possibly two different quotes and the client decides do they want it done, dusted and cleared in less than a day, or bring a crane in and have some roof alterations done through the insurance.

It may have been a condition of the sale... I buy the house, if you remove the tree..
Crane may have been the cheapest option....
The tree service may have a flat rate contract with Reliable....

heavylift said:

It may have been a condition of the sale... I buy the house, if you remove the tree..
Crane may have been the cheapest option....
The tree service may have a flat rate contract with Reliable....

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I dont see that ..tree companies dont use cranes if they can avoid it....there's just not the volume of work to justify cutting them a break ...I can assure you the savings dont start until a company has put more than $500,000 dollars a year in equipment hire ....
Sure Reliable wants the work ..but for a hand-full of tree's each year ..MHO ..not worth cutting them slack ....

Condition of sale is a very plausible thought ...
However in the articles where the couple were interviewed ..there was no hint that it was their intention ..
the removal was done because the tree was diagnosed with a disease and that it would become unstable and present a safety issue rather quickly ..
I'm not a tree guy ...but in some pic's and private video shot before it was cut into ..the tree appeared to be rather green and full ..

I had an interesting call a couple of weeks ago. A local yaywho..(That's southern for dummy) came by my office said he had a problem. He had contracted to remove this huge tree right next to a house. He took his saw, with a 16" bar and sawed all the way around, and the tree didn't fall.:Banghead:Banghead

He WAS cutting it from the top down in small chunks, but, his bucket truck blew a hydraulic line, and he couldn't find the right parts. He'd tied a cable to the tree, and tried pulling it over, but w/o any luck. He stuck the bucket truck in the lady's backyard and had ruts 2' deep.

He wanted me to bring the 50 ton Grove down and lay the tree down. I drove down to scope the situation out with him. The driveway up to the house was about 7' wide with steep banks on either side. After getting to the top of the hill, it made a hard 90 degree turn into her carport. The tree would be there on the left. There was no place to set the outriggers unless we jacked the entire rig up about 3-4 feet. It would be possible, BUT highly improbable.

IF I could get the rig up there...WHERE would we lay the tree? There was no place, except where the crane was sitting. SO, I asked the guy..WHY don't you just tie the cable back on it, apply tension and cut it down? He informs me..because his saw isn't big enough. So, IF I get the crane set up, and hooked to the tree, what would we do? He wanted me to just yank it off the stump. Nope..Ain't gonna happen. You'd HAVE to saw it into. AND..if you're gonna have to saw it into, why don't you just saw it into and let it fall? Seemed to me to be a LOT cheaper to get a bigger saw.

He seemed to think I could shake the tree back and forth until it broke off. If you want to get in trouble with a crane, start pulling sideways. Then we'd have the crane AND the tree over the top of the house. This was ne of those jobs I preferred to just drive away.

HA!HA! HA! ...Some people just dont get it ...:drinkup

I suggest you print the pictures from this thread.... then give them to him

liebherr1160 said:

HA!HA! HA! ...Some people just dont get it .

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Aint that the truth, its quite frightening just how nieve/stupid some people are. :drinkup

Thats what happens when you use a crane as a catchers mitt. Some times things go south.


I will say that particular crane company has a pretty decent record in this area for being a reputable and competent company.

I hope you all know that all arborists are not idiots, speaking from the perspective of a tree climber and a crane operator : trees that require the help of a crane should be left to experienced tree companies and climbers. If the rated cap. was around 6000lbs (estimated radius and boom angle) and the pick came out to 12000lbs then everybody on the site was at fault.

Everybody on this thread has been concentrating on the climber and the operator, in tree work the estimated weight of the pick should never exceed 50% of the rated capacity this will compensate for the wood being too wet or just a mis calculation.