Crane Operations/TD
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Lumberjack
Banned
If I stay doin trees after college I am gonna hafta get me a crane, probably a 17 ton, or similar, so moving it around aint such a problem.
I have never used a crane on a tree job, but I ran a crane during the summer a coupla years back for a comercial air/plumbing company. They had a small 10 ton crane with a short boom. when picking units off of the roof, or other times when swinging aint an option, I would always keep the cable short to fight the swinging. When setting a unit, I would lift the boom and let out more cable so the workers could move the units or their platforms with a minimal amount of effort.
After we cleaned out the units of any copper or compressors/ motors we would then fold them up (some were 20' x 10' and the biggest ones weighed 10,000 lbs.) so they would fit on the trailer to be hauled to the scrap yard.
Guess I need to ask around and see how much the smaller cranes cost per hour, I could probably save some money. Or just buy my own, new of course
.
Carl
I have never used a crane on a tree job, but I ran a crane during the summer a coupla years back for a comercial air/plumbing company. They had a small 10 ton crane with a short boom. when picking units off of the roof, or other times when swinging aint an option, I would always keep the cable short to fight the swinging. When setting a unit, I would lift the boom and let out more cable so the workers could move the units or their platforms with a minimal amount of effort.
After we cleaned out the units of any copper or compressors/ motors we would then fold them up (some were 20' x 10' and the biggest ones weighed 10,000 lbs.) so they would fit on the trailer to be hauled to the scrap yard.
Guess I need to ask around and see how much the smaller cranes cost per hour, I could probably save some money. Or just buy my own, new of course
.Carl
NebClimber
ArboristSite Operative
If you had to pick one cardinal sin in crane rigging, what would it be?
If you had to identify the most common mistake, what would it be?
Steven
If you had to identify the most common mistake, what would it be?
Steven
i'll ride a hook round turned in 2x and holding on with mouse closed, so i'll say......Setting chokers down too flat to the log. In the OSHA lifting/RigginG Manual , the sling discussion starts on pg. 49; and hammering down specifically treated on pg.61. This means don't choke the sling down flat to tree to avoid super leverad loading by same math as dip in speedline, spread DWT, use spreader bars on docks so that these forces don't crush the cargo etc. The idea is to let a relaxed 120o angle in choke meeting; that alone will put 1xLoad on each leg, any flatter than that, and the load per each side of the choke is actually greater than the load due to this leveraging. If you flatten this nose down to the log, to 170o (not quite flat), that places ~575% x Load on each leg (eye and what it chokes). That can become super loading under crane loads.
Also, in the AirForce/ Engineering Crane Certification Manual on page 55 treats this issue also (not to flatten choke to rule out slip). Both manuals treat the importance of the angle at the nose of the choke, as well as other pertinent discussions i think, to be used in general rigging as well as crane IMLHO. 2 good primers for that; these are the things in the crane operators head; that he was tested on; giving linking view to that.
i think that you always have to look for a trade off....... a shorter cable length gives more stability to side wobble; but at the cost of the boom being lower, in a more leveraged position; more easily overloaded. Though wobble can give some loading.
In some yards When it gets down to the big stem and strategizing how to get it down or up, and it isn't going to be 1-2 easy pieces, we've gone for felling; seeking to use the crane pull from top of stump to force tree over. That would force a strong hinge for softer felling. But could jerk on crane. i run a line from top of stump or over top and redirect from another tree stump to the crane. Now the crane can pull; reading on scale inside cab # of pull on line; that is leverged down the length from the hitch point to the hinge, and when tree falls, can't jerk crane (must keep line from redirect to crane from getting snagged by load though). Then piece, crane pieces. Redirect position takes ~2x line pull depending on angle between lines feeding to redirect.
i relate tree rigging without crane as rigging to a fixed boom for comparisons.
Many picture (scanner, camera etc.) software can resize. If your MSPaint, free with windows has been 'opened up' (like by installing MSOffice), or see the excellent page for many things also with directions for MSPaint Fix it can handle .jpg.gif ; might be some trouble just double clicking an icon to open in MSPaint, getting "Open With" box opening, then having to scroll down to "paint" (check box deal isn't 100%) even then; though try to force "Paint" to take pic like this before trying fix. Workaround is either drag/drop pic on to MSPaint shortcut on desktop, or go into (generally) "C:\Windows\SendTo"; and drop a shortcut to MSPaint (or whatever) there. Paint is generally in "C:\Program Files\Accessories\MSPAINT.EXE", or copy shortcut on accessories menu and paste where you want(desktop or make new "Send To" item. THen left click on a pic, and "Send To" Paint". Once in MSPaint pick the square looking dashed/cut out tool at top-R of list. On keyboard press "CTRL-A" for select all (whole pic). Keeping finger on "CTRL" key move other finger from "A" to "W" for "CTRL-W" for resize. Try "40" "TAB" "40" "ENTER"; to resize pic evenly on both sides to 40% size.
("CTRL-Z" to undo if you don't like.) GoTo/Scroll to lower right hand corner, drag to resize frame to pic shrunk down. Really nothing after a few rolls, some other softwares might flood with commands and easier resize too.
Also, in the AirForce/ Engineering Crane Certification Manual on page 55 treats this issue also (not to flatten choke to rule out slip). Both manuals treat the importance of the angle at the nose of the choke, as well as other pertinent discussions i think, to be used in general rigging as well as crane IMLHO. 2 good primers for that; these are the things in the crane operators head; that he was tested on; giving linking view to that.
i think that you always have to look for a trade off....... a shorter cable length gives more stability to side wobble; but at the cost of the boom being lower, in a more leveraged position; more easily overloaded. Though wobble can give some loading.
In some yards When it gets down to the big stem and strategizing how to get it down or up, and it isn't going to be 1-2 easy pieces, we've gone for felling; seeking to use the crane pull from top of stump to force tree over. That would force a strong hinge for softer felling. But could jerk on crane. i run a line from top of stump or over top and redirect from another tree stump to the crane. Now the crane can pull; reading on scale inside cab # of pull on line; that is leverged down the length from the hitch point to the hinge, and when tree falls, can't jerk crane (must keep line from redirect to crane from getting snagged by load though). Then piece, crane pieces. Redirect position takes ~2x line pull depending on angle between lines feeding to redirect.
i can go with'dat; vertical or whatever the target is to release. If i haven't calculated the amount of sweep to target, then minus some so crane can force faces together to force 'popping' free of hinge remotely with me out of area; i will make up for it in the boom to hitch angle. If there isn't to much sweep i might kerf into the face for dutchman type step/pop especially on heavy side across the hinge. Still using same tapered hinge, some dutch facing strategies; especially if i can observe them closely in large power for learning more of effects. Of course too much too bust/pop loose and ya have to go back in danger area/or jerks tree around real bad on release.
i relate tree rigging without crane as rigging to a fixed boom for comparisons.
Many picture (scanner, camera etc.) software can resize. If your MSPaint, free with windows has been 'opened up' (like by installing MSOffice), or see the excellent page for many things also with directions for MSPaint Fix it can handle .jpg.gif ; might be some trouble just double clicking an icon to open in MSPaint, getting "Open With" box opening, then having to scroll down to "paint" (check box deal isn't 100%) even then; though try to force "Paint" to take pic like this before trying fix. Workaround is either drag/drop pic on to MSPaint shortcut on desktop, or go into (generally) "C:\Windows\SendTo"; and drop a shortcut to MSPaint (or whatever) there. Paint is generally in "C:\Program Files\Accessories\MSPAINT.EXE", or copy shortcut on accessories menu and paste where you want(desktop or make new "Send To" item. THen left click on a pic, and "Send To" Paint". Once in MSPaint pick the square looking dashed/cut out tool at top-R of list. On keyboard press "CTRL-A" for select all (whole pic). Keeping finger on "CTRL" key move other finger from "A" to "W" for "CTRL-W" for resize. Try "40" "TAB" "40" "ENTER"; to resize pic evenly on both sides to 40% size.
("CTRL-Z" to undo if you don't like.) GoTo/Scroll to lower right hand corner, drag to resize frame to pic shrunk down. Really nothing after a few rolls, some other softwares might flood with commands and easier resize too.
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MasterBlaster
TreeHouse Elder
Dang Steven, thats a good question. Alls I can think of at the moment would be the tendency for tree co to try to use a crane thats really too small in an effort to save bucks.
Don't use a 17 when you really need a 30!
monkeypuzzle
ArboristSite Guru
Right on MB. Back in 1997 I started working for a very good arborist in North Carolina. First day on the job I notice a big red boom laying behind his shop. Came off a 17 ton truck crane.
25,000$ mistake he says. I took too biga log and the over she went.
I did a few crane TD's with him but didn't really care for that small of a crane.The other three climbers wouldn't get near the thing.I learned a lot from that arbo, he is one of the best out there.
25,000$ mistake he says. I took too biga log and the over she went.
I did a few crane TD's with him but didn't really care for that small of a crane.The other three climbers wouldn't get near the thing.I learned a lot from that arbo, he is one of the best out there.
MasterBlaster
TreeHouse Elder
I guess one common mistake would be not centering the ball over the load. Sometimes the operator can't see it as well as the climber.
Its up to the climber to make sure the ball is in the right position.
The climber should know all the signals for crane operation.
http://womanoperator.com/new_page3.htm
http://www.acratech.com/freedocs/Hand_Signal_eval.pdf
John Paul Sanborn
Above average climber
Trying to force the hinge with the crane
In this type of pick, is it not better to double sling. Using one on each side of the load so that it comes off even?
MasterBlaster
TreeHouse Elder
I imagine I 'force the hinge' every time I make a (crane) cut. Picking it up level (using 2 straps) doesn't become an issue until you get into the big wood, namely, the trunk. Then two straps are a must.
Rocky, you hit upon a pet peeve of mine. I HATE IT when they try to load the log straight from the tree to the truck. 99% of the time the log is at an angle like in the above pic, and that is a dangerous way to load a log.
Making the lift from the tree and making the lift to the truck should be two separate events. The log should be centered and as balanced as possible when being loaded. Easier and much safer, IMO.
Rocky, you hit upon a pet peeve of mine. I HATE IT when they try to load the log straight from the tree to the truck. 99% of the time the log is at an angle like in the above pic, and that is a dangerous way to load a log.
Making the lift from the tree and making the lift to the truck should be two separate events. The log should be centered and as balanced as possible when being loaded. Easier and much safer, IMO.
We always use 2 slings when it comes down to picking the stems. It has much less dynamics on the crane if it pulls straight up. With one sling it will shift and no longer be plum, unless the operator is good enough to move the boom. Two slings takes longer but is much safer because control is higher. I have and still am testing loads on cranes with a dynomometer, the results are "shocking".
John Paul Sanborn
Above average climber
What i have done with loading, is the peice comes down, the slings are moved so the log can be picked up horizontal..
Even if it is just yarding the logs up for future loading, it is so muc safer and neater then the operator trying to do pickup sticks.
Even if it is just yarding the logs up for future loading, it is so muc safer and neater then the operator trying to do pickup sticks.
Here's one I like to do. With those horizontal limbs or leads in my case usually I like to get it balanced or maybe error on the but heavy side a bit. Then for the cut, I make an undercut is on a horizontal plane as to leave a shelf. Then I make a top cut down to meet my bottom cut. 9 out ten it just sits there but free and you can put your saw away get ready go to your next spot. Then the operator can just take it away. You can modify your top and bottom cuts on angles to counter twisting that you may anticipate.
Well i guess that would be like a snap cut lifting up, rather than it's own weight pulling down? So, but heavy, seeing as butt would leave last, would keep it form re-versing direction after tearoff?
How be's Daniel?
edit: Tip a couple of logs out there to let logs down to to ease moving/removal of the chokers.
How be's Daniel?
edit: Tip a couple of logs out there to let logs down to to ease moving/removal of the chokers.
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I would have to say the one cardinal rule would not to lift the load over the climber's head. I had an operator who would do this all the time. Lift a log move a few feet left or right and continue to just keep lifting it straight up over my head. My thought is that the pieces need to go down to the ground.
Another good one is not to pick the climber up until he is unclipped from the tree. That also used to happen to me all the time. I guess that's what I get for calling the operator a retard and belittleing him everyday.
Another good one is not to pick the climber up until he is unclipped from the tree. That also used to happen to me all the time. I guess that's what I get for calling the operator a retard and belittleing him everyday.
Matt Follett
ArboristSite Operative
In an attempt to defend myself
On those single sling vertical lifts, I place a small kerf (notch on the oppisite side of choke, then I bypass cut from under the choke, above the kerf, when I get just to the kerf cut, I signal up on the cable till the 'hinge' moves slightly but not closing the kerf.
Then I bypass past through the 'hinge'. Pull the saw out, lean back and signal up... since all the fibres are cut, the piece tips, closes on the cut and splits, and smoothy lifts... generally.
When stuff gets over 2-2 1/2' in dia, then I always double sling, unless it has a central point, like where the crown breaks or what ever.
Cardinal crane rules:
Yeah, make sure the crane opperator moves stuff away from you...
Like in tree rigging, always overbuild...
put up miles of danger tape around the work area, and have a sniper ready to pick off those that cross... This spring we had a pedestrian walk right past the road closed sign, under the tape and UNDER THE PICK that was in the air!!!!! The ground crew was yelling, signaling practically thorwing things and got no response!!!
On those single sling vertical lifts, I place a small kerf (notch on the oppisite side of choke, then I bypass cut from under the choke, above the kerf, when I get just to the kerf cut, I signal up on the cable till the 'hinge' moves slightly but not closing the kerf.
Then I bypass past through the 'hinge'. Pull the saw out, lean back and signal up... since all the fibres are cut, the piece tips, closes on the cut and splits, and smoothy lifts... generally.
When stuff gets over 2-2 1/2' in dia, then I always double sling, unless it has a central point, like where the crown breaks or what ever.
Cardinal crane rules:
Yeah, make sure the crane opperator moves stuff away from you...
Like in tree rigging, always overbuild...
put up miles of danger tape around the work area, and have a sniper ready to pick off those that cross... This spring we had a pedestrian walk right past the road closed sign, under the tape and UNDER THE PICK that was in the air!!!!! The ground crew was yelling, signaling practically thorwing things and got no response!!!
MasterBlaster
TreeHouse Elder
Its all good, Matt.
Post some more pics!
Post some more pics!
MasterBlaster
TreeHouse Elder
Just the big stuff.
John Paul Sanborn
Above average climber
One on each side of the log, preferable choked using a clevice.
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