Safe rope use to guide a falling tree.

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sgbotsford

sgbotsford

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I have a bunch of tall poplar that are nearing end of life, and are leaning the wrong way to fell normally without putting house, barn, or shed at risk.

Check my calculations:
A 2 foot diameter poplar with have a stump area about 3 square feet. 80 feet tall. Let's assume that the branches make up for the trunk taper and for weight purposes it is a cylinder. 240 cubic feet.

Wet poplar at 40 lbs/cuft gives me a mass of 9600 pounds -- about 5 tons

If it leans 15 degrees, (over estimate) then there is about 25% of that load is in the horizontal direction. 2400 lbs.

I have 150' 3/4" nylon solid braid) rope with a rated breaking strength of 20,000 pounds in new condition, with an eye splice on either end.

My thought is put a messenger line into the crown, draw the rope up and over, bring the eye down, and pass thorugh. Attach the other end to my tractor (Deuzt 55 hp -- weighs about 3 tons)

Coefficient of friction on a tractor tire on firm soil is aobut .5 So maximum force tractor can put on rope is about 3000 lbs.

So use the tractor to tension the rope until wheels start to skid, OR it stretches 8% (Estimate of elastic stretch. I have an inquiry with the rope maker for this number)

My plan was to make the wedge cut first, then tension the rope, then make the back cut.

Is this a reasonable approach?
 
TheJollyLogger

TheJollyLogger

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Yes, plus one on googling barber chair, and the difference between compression wood and tension wood.
Short version, you are applying more force than you need, and applying it too soon. You are dealing with a 60' fulcrum, after all. Once you get your line set, I think you will be surprised at how much you can move the top by hand, and also the bow it puts in the trunk.
 
Ted Jenkins
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It sounds like a plan for disaster. A tractor to pull a line pretty dumb. Two average come a longs would create more force. If you are using what sounds like a decent rope near the upper portion of the tree then good. You need to find some thing at a reasonable distance to use as an anchor. Using at least one snatch block seems essential. Also chain or cable could be used to extend your working area. Thanks
 
old CB

old CB

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Plus one on the tractor applying too much force. Get a one-ton come-along and anchor to something solid at enough distance that you're pulling away from the tree rather than down on it. When you tension up the come-along on the rope you'll see the top of the tree bend toward you, telling you you've got a good pull going. Be sure to attach the rope about 2/3 of the height of the tree. Too low and you lose leverage, too high and you could pull the top out.

When you've done this a time or two it will seem a simple job.
 
Bearcreek

Bearcreek

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I have a bunch of tall poplar that are nearing end of life, and are leaning the wrong way to fell normally without putting house, barn, or shed at risk.

Check my calculations:
A 2 foot diameter poplar with have a stump area about 3 square feet. 80 feet tall. Let's assume that the branches make up for the trunk taper and for weight purposes it is a cylinder. 240 cubic feet.

Wet poplar at 40 lbs/cuft gives me a mass of 9600 pounds -- about 5 tons

If it leans 15 degrees, (over estimate) then there is about 25% of that load is in the horizontal direction. 2400 lbs.

I have 150' 3/4" nylon solid braid) rope with a rated breaking strength of 20,000 pounds in new condition, with an eye splice on either end.

My thought is put a messenger line into the crown, draw the rope up and over, bring the eye down, and pass thorugh. Attach the other end to my tractor (Deuzt 55 hp -- weighs about 3 tons)

Coefficient of friction on a tractor tire on firm soil is aobut .5 So maximum force tractor can put on rope is about 3000 lbs.

So use the tractor to tension the rope until wheels start to skid, OR it stretches 8% (Estimate of elastic stretch. I have an inquiry with the rope maker for this number)

My plan was to make the wedge cut first, then tension the rope, then make the back cut.

Is this a reasonable approach?
The equipment you mention, (rope and tractor) should work fine for the job, if (and these are big ifs) your height and lean numbers are correct, the trees are in good enough shape to hinge well, you get the rope secured correctly at the right height, the tractor has good traction and you make your cuts properly and in the right order.

You don't want all the tension put on the rope before you do the back cut if the trees are leaning that much. Some tension is ok, but most shouldn't be applied until the cuts are made and the tree is ready to go over.

Definitely do not pull till wheels skid and how would you actually measure 8% stretch anyway?

Based on your description, I'd say you have an excellent chance of breaking something during this endeavor. 😉
 
Brufab
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A winch is made for work like this.
I did alot of winch work on popple trees 18-30" diameter on my dads lot he's building on in n michigan. Bought the biggest winch from norther tool. Worked quite well. We used cable and heavy straps. I usually made the notch a bit bigger and let him tension the tree and when I made the back cut he would run the winch. Also most of the healthy looking popples had some rot in the base. We had to cut alot of trees that the logger wouldn't take because of that.
 
sgbotsford

sgbotsford

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Good points. Thanks.

One person asked, "How do you measure 8 feet of stretch?" 150 feet * 8% = 12 feet. Move tractor to where it's only snug. Drive 12 feet further.

Re: Barber chair. I've had a couple of these. While not a pro, I have cut 5-8 cords of wood a year for 30 years. The barber chair occurs when the side away from the cut is in compression, and the tree has weak grain. This frequently happens when the tree has been leaning for some time, with the downside in compression and the up side in tension. The plane where tension and compression meet is frequently weak. But to be sure, I followed his instructions and read this article: https://blog.lewistree.com/blog/barber-chairing In this article he mentions strapping the trunk with a heavy duty ratchet strap, as well as the standard escape route stuff. The ratchet strap notion was a new idea for me and seems a good one.

Pre tensioning. I've done this before, but without the numerical considerations. I was working then with smaller trees and 1/2 rope. My first one, I put what I thought was a reasonable amount of tension on the rope, but as the tree started to all, this slacked off the rope, it fell at about 45 degrees to the intended angle, and smashed a picnic table to firewood. I realized then that I'd been tricked by rubber band nature of nylon.

A cable, have much less stretch would be worse. The tree moves a foot and is no longer in tension. At that point it goes whatever direction it wants.

You want to be able to put tension on the tree until it is clearly falling in the direction you wish.

My worst tree is one only about 15" in diameter, but has a serious lean to the SSE. I'd like it to fall NNE, but will accept anything north of east. Attaching at the 2/3 point, I need to have enough northward tension to keep it moving that way for about 7-10 feet.

Snatch block. Good idea.
 
Brufab
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If you could use cable that would be good. I have alot of bullrope it's called that we got for the job but never used it. Maybe 1/2 or 5/8. Says for arborists and loggers. But when cable is available I always choose cable. Also how big is your tractor. One thing I learned is that when you hook high up in the tree 15-25' the tractor looses traction as it pulls tight the rear end lifts up alil. Worse case scenario tree goes backwards with an operator on the equipment. Lots of youtube video of that. I have even used chain comalongs before I would tie off to tractor. Tractors I have are 9n 600 series and 900 series
 
kelseyboy

kelseyboy

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Yep , use a winch or a good come along ( hand winch) with an anchor. Tree, or parked equipment with a brake applied. I don’t use equipment as Anchor unless it’s 5,000 lbs or more. It’s turned off. Too much variation with tension, brakes power surging, traction etc. I will never use a moving anything to pull over a tree. Slow and controlled is key.
 
Brushwacker

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If u use a tractor or truck , communication and timing is critical when to pull. To much tension to soon easily could cause a barber chair , to small of a vehicle could be ineffective pulling also and be alert for all sorts of unexpectations. I probably done this about 100 or more times with several different people. Little over 1/2 inch bull rope is what some of these tree guys used. Looks a little small to me but I don't remember it ever failing. Giant trees I personally would want to go bigger or use cable and heavy enough equipment for the pull and have a good relationship with your Creator !
 
Bearcreek

Bearcreek

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Good points. Thanks.

One person asked, "How do you measure 8 feet of stretch?" 150 feet * 8% = 12 feet. Move tractor to where it's only snug. Drive 12 feet further.

Re: Barber chair. I've had a couple of these. While not a pro, I have cut 5-8 cords of wood a year for 30 years. The barber chair occurs when the side away from the cut is in compression, and the tree has weak grain. This frequently happens when the tree has been leaning for some time, with the downside in compression and the up side in tension. The plane where tension and compression meet is frequently weak. But to be sure, I followed his instructions and read this article: https://blog.lewistree.com/blog/barber-chairing In this article he mentions strapping the trunk with a heavy duty ratchet strap, as well as the standard escape route stuff. The ratchet strap notion was a new idea for me and seems a good one.

Pre tensioning. I've done this before, but without the numerical considerations. I was working then with smaller trees and 1/2 rope. My first one, I put what I thought was a reasonable amount of tension on the rope, but as the tree started to all, this slacked off the rope, it fell at about 45 degrees to the intended angle, and smashed a picnic table to firewood. I realized then that I'd been tricked by rubber band nature of nylon.

A cable, have much less stretch would be worse. The tree moves a foot and is no longer in tension. At that point it goes whatever direction it wants.

You want to be able to put tension on the tree until it is clearly falling in the direction you wish.

My worst tree is one only about 15" in diameter, but has a serious lean to the SSE. I'd like it to fall NNE, but will accept anything north of east. Attaching at the 2/3 point, I need to have enough northward tension to keep it moving that way for about 7-10 feet.

Snatch block. Good idea.
I'm familiar with how to do the math. 🤪 Maybe I should have worded that differently. You have too many other variables in play to count on a specific amount of rope stretch to do the job. You don't need any stretch at all in the rope to pull trees, which is why cable works just fine. You put tension on the tree to get it to start falling the right way. Once it's falling, rope tension should not be counted on to do anything at all. If it goes the wrong way at that point, you screwed something up, probably your felling cuts, possibly your estimation of the condition or hinging ability of the wood. FWIW, I say all this as someone who has done tree work professionally for over 20 years. I'm not basing this advice on theoretical math, I'm basing it on decades of experience.
 

ArtB

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I use wire rope and blocks.
And add a couple of wraps of 3/8 chain around the trunk above the cut to retain any possible barber chair.

Enough blocks, no need to cut, pull entire root ball out. 2 FT DIA tree like yours should come out with about 60,000 # pull 20 ft up or so.
 
Maintenance supervisor

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My math equation is ,over spec everything!
I never- repeat "NEVER " use any rope less than 3/4" bull rope. If your calculations are so exact that you are figuring out % of stretch then you haven't met nature .
No one knows whats inside of a tree ? What if there's a old T post in there? Half way through your cut? Now your breaking it over , is your rope strong enough? What if its hollow 6' feet above your hinge?
Essentially dont play with figures, get a snatch block a the biggest and longest rope you can afford.
2 person job.
 
magneticanomaly

magneticanomaly

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The idea of using rope stretch is fine, because it will provide continuing tension in the right dorection...for a while. You did calculation of required initial tension to overecome lean...as tree moves, even in almost-correct direction, rope stretch will decrease and so will tension...you could calculate if the diminishing tension will be sufficient to maintain motion in the correct direction. The way to get more movement with less decrease in tension with a springy rope is to make the rope longer.
You could do this with a block, but better is to choose a more distant anchor, because then the pull will be more horizontal.
Which brings me to the idea of using a tractor as an anchor. Don't! Your calculation appears to assess the tracto'r effectivenes as an anchor as realed to its weight and coefficient of traction. But 1) traction will be unpredictably influenced by looseness/moistness/vegetation etc under each wheel, and will change abruptly if the tractor starts to drag. 2) and more important, the upward component of the pull is taking normal force away from the tire contact patches.
I agree with the comment that this is not a 1-man job. My preferred anchor is another tree. If you have a winch on a piece of equipment, here is the safe way to use it. Chain the tractor or truck to a tree on the end opposite the winch. Run winch cable from winch through a block chained to the base of another tree, and from there up to the tree you are pulling down. The truck-anchor, truck or tractor, and block anchor MUST all be in a straight line! . A wire rope will have little stretch, so you have to have enough line speed to maintain tension until the tree is well on the way down in the right direction. You may beeen an additional static line off to the side to another anchor to prevent tree from going the wrong way. Always consider how the distances nad line lengths will change as the tree moves.
 
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