If this is a repeat, please delete. http://www.sfgate.com/cgi-bin/article.cgi?f=/n/a/2009/11/17/state/n120434S96.DTL
sounds like some of my luck A crew is working to remove a 100,000-pound crane that toppled onto a Santa Rosa house and smashed it in half. No one was hurt in the Monday afternoon accident, which happened as workers were removing an unstable oak tree in the front yard. Rich Kingsborough of Atlas Tree Surgery, which was was removing the tree, says a large section of the tree that was connected to the crane suddenly broke loose. It yanked the 131-foot boom down onto the house and vaulted the cab into the air. It wasn't the day's first piece of bad news for Kevin and Michelle McCarthy, who had just moved in to the home in August. Michelle McCarthy says she had gotten into a car accident earlier Monday, and the couple was in Marin County dealing with the crash when they got the call about their house. Read more: http://www.sfgate.com/cgi-bin/article.cgi?f=/n/a/2009/11/17/state/n120434S96.DTL#ixzz0XDpGrNKX
This happened about a block away from my sisters house. This is what she wrote me..."So there was an accident with the crane that was removing the oak tree from behind that house in our neighborhood. I was driving back home this morn and saw a ton of cars on the street with firetrucks, etc. Then I saw this....check out the attached pics. Luckily no one was home at the time." Thats about all I know about it, here a a couple pics she took from the street.
so......they're lifting up the truck body to relieve pressure from the boom so they can suck it in?? The operator had to have quite a load in his drawers!! Looks awful far to be lifting with the jib on............but then again.......I ALWAYS measure because I KNOW that looks can be decieving!!
Usually when a boom gets that type of damage they just take it off with the gas ax. It's appears to be close to fully extended so its at its weakest. The machine has been stressed now so it may be a total loss. It will take a mechanical engineer to inspect and sign off on whether or not the unit can ever be used again. The interview also sounds kind of odd. A piece breaking off a suspended load would make the load lighter. I'm thinking someone over rode the safety with the boom extended and low. Any load at all would have set the teeter totter in motion. Thanks for the photos.
if you look at the pics in the link.....pics 3 and 5....looks like he still had another section of boom left...
There is quite a bit more info on this on arboristsite.com http://www.arboristsite.com/showthread.php?t=115443
Too heavy yer think ! Doh! somebody made a massive weight miscalculation. A very large lump of timber must have had the oppurtunity to drop a good distance to stand that up like that. Maybe the crane got excited about the job!
Just curious but does it have removeable counterweight... if so was all of it on the crane.. I wonder if when they chainsawed the tree and if it had enough tension on it that when it broke free... it shot up a bit then pulled the crane over when it fell to the ground..
No, the tree fell ..taking the crane with it .. Tree's not to trifled with ...the tree removal gang ought to be liable and responsable for the whole gig...insured and by all acount own the crane when its put into gear on one of those job's ...maybe when they hold the bag ..they'll get the hint .... Thats a sad position to be in as an operator ..
:lmao
My math is rusty... F=ma tree mass for a number is 2000Kg's Acceleration 9.8m/sec/square F=192080 newtons of energy which is 43181 lbs of energy ..if it free fell for one second ...I dont have the constants for air resistance ... It really dosent have to get big to get heavy ...in a hurry ..
I would NOT want to be the neighbor, (see attached pic) I'm sure the crane they put on this driveway will do some damage. I feel bad for the homeowners, glad the operator was okay.
Look at the size of that chunk they cut !! Hope I never see another tree!!
With that much of a reach they should have took smaller picks. I have used a crane for taking down trees and that is always the rule of thumb for us. Without any access to the back I would be curious to know how they even got the pool in there.
Dang!Looking at the picture D5G posted,I dont see any counterweight on the toppled crane!It looks like a Grove/"krupp".Heres what one looks like with 100,000 lbs of counterweight on the rear.
Yes there was counter weight on it .. There was the top slab and the 10t slab ..Its the black stuff on the back of the superstructure .. http://www.sfgate.com/cgi-bin/article.cgi?f=/n/a/2009/11/17/state/n120434S96.DTL roll the pictures you'll see it .. If there had been more the boom may have buckled before she tipped .. look at the trailer.. the operator didnt have anymore ..that job was evaluated by a company representative first ..no operator in his right mind would set up for a tree ..or anything he has to reach for without bringing all the avaliable stone on board ..unless it made no difference to the chart to have it on board ..
Trees stink. They can be the toughest crane work, and this job looked like a doozy. #1 that's a big tree, really close to the house, the weight is always changing as you go down the tree cutting pieces, making it impossible to give exact weight to the poor operator, and when he cut that last piece (looks like 15' up) it was too much weight. #2 The operator was in the blind for the whole job, he couldn't even tell them to take a smaller piece because it looked like they were cutting off more than he could handle. Radio communication is okay, but eyes are better. #3 There were probably climbers in the tree (no bucket truck access), and when they cut the trunk sections loose, things move on the tree. If you're cabled up too much it shoots up when they cut it loose, too little cable up and it shock loads the crane. Trees are complicated and dangerous. Also, the crane picking up the front of the carrier is actually catching the rig on the way back over. They're using one crane to pick up on the boom until the crane comes back over center, then letting it down with the crane hooked to the carrier. The boom is repairable, they don't want to hurt the crane any further. Fixing the house will be expensive enough, you can't write off a $750,000 rig too.
In my neck of the woods They would send up 2 climbers with rope & chainsaws & take the tree down like "eating an eleghant"Take a small piece at a time.Haul the tree out of the back yard with wheel barrows & dump it in the chipper.There is a time for big equipment,and a time for old fashioned muscle power.
Hey 25c i agree with you 100 % , but the new young operators don't seem to see it that way ! Houses should not be built so close together , if there was a 10 ' easement between the houses the old Insley could boom up 80 degree and let small sections straight down. I said Insley because if you were at base ot tree it would be a simple task and this huge Hyd. Beautiful Crane would not be where it is now .
I here ya dozerbill57.We were working on a 200 foot TV tower today ,stacking sections with a winch rig & gin pole.No crane ,I Love it! We got some great young climbers on the Towers.I'l post some pictures later.
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
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.
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.
25c is right, i would cut/split it and used for BBQing red oak = good BBQ!
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.
well, the whole point of the crane was to keep the tree from falling on the house,.......in a way it kinda worked. lol Pj
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.
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?
It appears that what he was attempting to lift is laying under the boom, not the tree next to the house... which probably where the one under the boom was
: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!
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.)
Welcome aboard rbtree and thank you for a very good insight into the potential problems from somebody who has been there and done it.
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
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?
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....
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]
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
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.
Welcome To the forum rbtree & cool job pictures.That big ole Stihl chainsaw makes the Grove crane look small in the last picture.
Is this crane one that resets everything when it's restarted. I ran a 28 ton in the mid 90's that you had to reprogram the LMI everytime. I was wondering if that crane would relevel if restarted I seen the less rate thing when Belger comes on a job... They brought a 6 wheel linkbelt {100+ tons}to lift about a 1000 pound... I talked to the main guy.. he said that was the only crane that was available.. and they charge for a little crane... I worked for a company in the late 80's that all the job trailers there was several books .... with all the load charts.. sizes ...weights of machines ... all the other stuff available for whatever model of crane...
No ..once the outrigger's are set ..she's good to go .. Most LMI's do have to be reset after a restart
I was asking about the axle lockout system.... sorry about that.... My post does sound outriggerish...
That Grove ..Yes the suspension is locked out via a rocker switch on the dash or by turning the ignition to the off position .. Normally when I set those units up this is how i do it .. #1 raise suspension a little (depends on my mat thickness)and lock it #2 get on half outtrigger's #3 set my mats or steel plates next to the outtrigger jacks .. #4 boom up to 76degrees or better ,swing to the rear ,positive house lock in ,electric swing brake engaged #5 raise the jacks one by one,one by one extend the outriggers to fully extended position, pin an dog them .. #6 unlock the suspension, turn suspension key,press all lower axle button,drop the axle pressure's to 0 psi (This can be site spacific ..but on level ground ..all lower).level the crane on outrigger's and kill the carrier.. #7 hook onto my counter weight ,set it on the carrier ,swing to rear ,house lock in ,,raise and pin counter weight to the crane, retract counter weight jacks ,, switch to scope and drive out the boom .. Takes about 30 minutes.. if I only have one load of counter weight ..
www.pressdemocrat.com/article/20091125/ARTICLES/911259959 came in at 12,000#
nothing like doing a job with millions watching... that's another bad thing about putting you name on the boom... billboard.... might have to put UN on front of the name....
Thats crazy they still picked the tree over the home bringing in a bigger crane to do the job . This is part of an OSHA investigation?What's to investigate?It's hard to believe that an OSHA ivestegator would go along with or be a part of that job.Thanks for posting the artical TSK415.We are all for safety on the forum ,If I was the OSHA inspector,I'd say send a few boys around the back a that house with chainsaws and turn that 12,000 pound chunk into firewood so the carpenders can start fixing the damage on the home from the first episode .
I think the osha guy was there to make sure his piece of wood wasn't altered... Plus may have it hauled to get a certified weight... to help with the investigation..
I have never done tree work with that large of a crane but worked with company with a crazy climber he was good and the boss got alot of jobs becuase the climber could do jobs that no one else would touch without a crane. We did alot of block and tackle work and the trick was in the cut and how it loaded the ropes We had a crane on a job but it wasnt reaching over the house but the operator was clear no quick cuts ease the load onto the crane. Im with JB the climber either forced the cut or misjudged the noth. I had thought maybe he hit a bad spot on the trunk but it looks solid from the pictures.
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.
Trying to figure out how to post a photo.
another
might be a day or two before he answers.... but they look good... better weld a name and some kind of id#... nice stuff will disappear.... If that does work a little bit of hot pink paint do you have any photos of when they were being built...
Sorry. That is the only photos I have. We're just now finishing them. We're going to paint them black I think. Pink just doesn't sound right..Although..might keep someone from stealing them..:thumbsup
:yup thats the idea. Here in the UK big plastic? mats are very common. I say plastic but maybe a member of that family But I suppose they still need a solid surface underneath, which is why you have made those.
Why wouldn't they just cut it in half? :beatsme Pretty dumb guys if you ask me. ointhead
Evidence. I bet a lot of work will be done with that lump of wood including balancing, reslinging and very close analasis of the cut. Somebody is going to pay. The question to be answered is who?
Before the accident that would have been a good idea... (1)the cutter may have lied to the operator....My next cuts here... he says cool.. then moves down the tree for even a bigger chunker... without the operator knowing the added weight.... (2)everyone was in a big hurry to get to the bar.. .. I can handle that much weight... (3) everyone's trying to save a buck... on both sides.... not enough counterweight on crane.... cutter trying too big of cut, so he get the job done in the minimum time a company charges..
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.
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 ..
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..
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 ..
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
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....
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
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.
This pick came out to double the rated capacity, a mistake this large should have been noticed by somebody on the site. They were most of the way through the job so an experienced crew would be able to estimate the weight to within 100 lbs.
Here's a better site than arboristsite.com: http://www.treebuzz.com/forum/showflat.php?Cat=0&Number=202540&an=0&page=0#202540
While I humbly agree ..Fact of the matter is the crane being sent should be only working a duty cycle chart (60%)when doing a tree as its never a straight forward pick of the ground as the crane is intended .. I do like your Idea of 50% .. put the boom angle aside ..these European cranes as with just about all other cranes,the angle only come's into play when the boom is working on less than predetermined boom lenght's ..the crane in question was working within its chart with a predetermined boom lenght and boom configuration .. even with one section retracted..
Actually I found this thread more entertaining http://www.arboristsite.com/showthread.php?t=115443&highlight=crane
Says your an operator in your public profile ..what class Ontario license do you hold ? 339()?
I currently hold a 339(C) and within a year or so I'll challenge the 339(A)
the picker ticket ..up to 15 T ..thats how we all start ..I hold a A with red seal .... the exams are not that much different from the C ..just more attention to crawler and the old Grove charts ...theres also question's about setting offset on the old Lima and American cranes ..If you can find a manual for either and go through it .. All the best on getting the A ..
Thanks for the info, my dad challenged the A and got it in September, he had an unlimited capacity licence for anything with rubber tires until they switched to MTCU, at the time he was running a 15 ton so they grandfathered him in with only a 339C. He's very close to retirement so the testers didn't understand why he was upgrading, but he is my sponser so he would have to, so I could get mine.
I want to let every operator here(especially those from Ontario) know that the province of Ontario now teaches arborist apprentices how to work with cranes, I've been a teachers assistant for this crane course for the last two years(aslong as the course has been running), my dad is the teacher and we teach as much as we can about load charts, range diagrams, proper rigging techniques, proper cutting techniques, etc. This past year we put on a course for the Ontario Commercial Arborist Association and also the City of Ottawa Forestry crew. The one we did for the OCAA we had two crane operators there that a couple of tree companies commonly hired, we were worried that they were going to scruntinize us, but afterward they told us that we really knew what we were talking about and they learn't quite abit even though they expected the exact opposite.
How close do you guy's work with OETIO ..Are these guys being taught to work the cranes or understand enough to work with an operator .. Its a fine line telling somebody what can or cant be done ..then turning them loose .. Like this one guy (non-arborist) i had for a client ..thought 10 feet from power lines was when you start to get safe and becareful ..cuz they know your gonna get closer and we should be able to get to with in 5 feet .. :badidea telling some guys to much poses just as much agravation as them not knowing ..this throughly depends on the individual ..
We don't work with OETIO, I would not have any problem working with them but i doubt they would want to work with us because we are non-union. We are teach how to work with the assistance of a crane, how a crane works and what to expect of an operator and what an operator expects of you. We show them accidents just like this one and explain what happened. We mention limits of approach, but there is only so much you can teach in 3 days and they should learn that from the rest of the arborist course.
Absolutly wrong there ..The school has opened talks with the non-union concrete pump sector to set about a reputable traing and appreticeship course ..they have in the past invited other facet's of the non-union labour sector to training seminar .. Think about it ..Its either we're a team out there ..or we're all screwed ..Wouldnt hurt to touch base with them .. and dont worry ..Union Labor overtone's wont resound through the doors ..just call'em up and explain who you are and what it is your trying to accomplish ..or a "mandate" as it is ..and roll the bone's ..its only the cost of a phone call .. it makes my life and our job's alot easier when we can mesh on site .. hey Kudo's for getting yer guy's up to speed
Sounds great I'll make sure to call them