Guy rope angle for side lean pull over

[Bart_]

Few links:

Pull Rope Height - what is optimal?

Continuing from another thread about the difference between basal vs. canopy anchored pull lines for dropping trees, here's another question: If I have a tree being felled and I want to pull it over using a rope tied directly to the trunk up top, assuming that I'm pulling on level ground, from...

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Physics Question: Basal vs Canopy Anchor Forces

When setting a line in the tree to use to pull it over, what is the difference in forces between a basal or canopy anchor? In an attempt to be more clear: say you set 2 lines 60 ft up two identical 100 ft trees and then pull on them from 150 ft away one is tied off just above my notch and one...

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Another physics spinoff question - back leaning

So far we've solved for three cases of puling a tree over' First was set distance from the tree, what height/angle to set the rope. (diminishing returns) Second was set height in the tree, what distance/angle to place the winch. (diminishing returns) Third was fixed length of rope, what...

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Bit more iteration on the side guy line concept, with the objective of keeping it constant length/tension during the fell.

Straight vertical tree - guy line 90 deg to the fell direction, the giant fictitious plastic right triangle is easy to apply, pivot the triangle on its bottom edge, top tip traces the trunk fell arc to landing, the hypotenuse is the guy rope, the bottom edge is straight line from your hinge to the guy anchor, hinge is cut regular perpendicular to trunk axis

Side lean away from guy (wouldn't guy towards!) - If I've got Dan right, you hold the giant right triangle against the leaning stem (perfect side lean 90 deg to intended fell lay) now to keep the hypotenuse length constant during fall arc the triangle base is angled up not parallel to the ground, I interpret Dan's rule as 5 deg lean = triangle base 5 deg up from level so the anchor is some number of feet up the anchor tree to achieve the angle, and the hinge is cut regular perpendicular the the trunk axis which makes it aligned to the triangle base pivot axis, so the hinge and guy line arc agree with each other. I could call this the guy line elevated anchor point method (?)

Side lean away from guy (wouldn't guy towards!) - I'll call this the normal guy anchor plus angled hinge method - this time your giant fictitious triangle isn't a right triangle, it's e.g. 95 deg so the base edge goes parallel to the ground from the guy anchor to the hinge, the "vertical" edge goes up the leaning trunk and the hypotenuse (guy rope) just goes from the leaning trunk to the guy anchor per normal. The hinge is cut NOT perpendicular to the trunk axe but instead e.g. 5 deg off axis instead aligned with the bottom edge/pivot axis - so it agrees with the arc made by the guy line. The only functional difference is the arc and landing location of the triangle top tip, a bit further out.

The objective or achievement of these strategies is maximum agreement of the the felling arc and the bending axis of the hinge for maximum reliability and no excess forces or slack or force jolts (catching/correcting fell arc mid fall) during the fell.

I'm hoping I've reinvented or re-described knowledge that's already out there in a book somewhere. Seems pretty logical, must've been done already.

 

[shaddart]

that makes perfect sense. Thanks!

so how do you handle it when the side lean is not perfectly 90° from the felling direction. oh, I guess you would just try to find a guy anchor that was opposite of that lean, no matter what, and use the height to compensate for the amount of lean. I think I'm getting it now.

and I guess hypothetically, you would tighten the guy rope, until you just barely started to wiggle the trunk.

and I guess in the scenario, the height of the guy rope on the tree that we felling doesn't affect the angles, but might affect interference i.e. if it was really high, that means the triangle will take up a lot more area in the woods/ yard and might connect with another tree/ building.

I also wondered if it was too low, and the hinge just completely broke free, could the butt scoot towards the guy anchor, allowing the top of the tree, to go more off course in the direction of the lean. .

 

[Dan Thornton]

could the butt scoot towards the guy anchor, allowing the top of the tree, to go more off course in the direction of the lean.

Guy line needs to be attached to the falling tree higher than Center of Gravity to avoid that potential disaster!!

 

[Daniel]

Guy line needs to be attached to the falling tree higher than Center of Gravity to avoid that potential disaster!!

2/3 is a good height to shoot for, just like cabling, but it can help to go higher as long as the tree will hold and the line angle isn't too steep. Whatever the angle used for guying telephone poles (about 32 degrees if I remmeber that right or maybe 37) is a good angle to shoot for, though not always achievable. Flatter is ok, steeper can get a little dicey depending on size, but can help plenty enough if you can get enough tension on the system and have the line set high enough.

Ropes shouldn't matter that much. I use true blue which works but has some stretch in it. That just means a little more work getting it tight. If the angle of the anchor isn't quite right you can leave some slack in the system You just have to eye ball it. You can also try to take slack out of the system with a portawrap or other friction device if anchor is off in the other direction. You shold be able to build a ground anchor string enough to hold on all but the biggest of tree.

When there are other trees in the way I use an old school porty and 4 wraps, with instruction to take a wrap off as soon as the tree clears the obstacle... if there are three wraps or less, the rope can usually move fast enough to prevent damage to the obstacle trees, though I wouldn't try that on a young or fragile tree or shrub.

as far as hieght of cut goes, it shouldn't matter much between ground and hip height.. Up and down hill is too much to think about now, but be careful if going down hill... I have broken a rope doing that.. the tree just wants to keep going after it hits...

 

[Daniel]

There are many dynamics to be considered when pulling a tree. I think the most trouble people have is grasping how often “less is more” when doing tree work. The balance between internal hinge mechanics and external pulls takes time to appreciate.

I'm in the more is better when you know what you're doing club... Higher pull lines and more pulling power allows more hinge wood to use for holding as long as that hinge is cut in a way that allows the fibers more flexibility and more even tension across the hinge from back to front...

 

[Daniel]

I am convinced that without that beefy side rope that tree would've smashed through those targets.

100% guarenteed you would have lost that to the side weight without the guy line. Punky ash has nothing to hold against side weight. We just did one very similar which I felt the hinge wood pop when the back cut was no where near close to forming a hinge... After I heard the pop, I looked up and the top was waving around because it had moved then suddenly stopped when the guy line caught it. There isn't much in the video showing the guy line, but the hinge was a mess to behold... I'll try to find the links:

This one would have been lost without the retainer line.. qued to the middle of the cut. The retainer line is visible at the beginning of the video:

tough to see on this one, but there is slack in the guy line which gets taunt at the very end of the fall:

 

[shaddart]

100% guarenteed you would have lost that to the side weight without the guy line. Punky ash has nothing to hold against side weight. We just did one very similar which I felt the hinge wood pop when the back cut was no where near close to forming a hinge... After I heard the pop, I looked up and the top was waving around because it had moved then suddenly stopped when the guy line caught it. There isn't much in the video showing the guy line, but the hinge was a mess to behold... I'll try to find the links:

This one would have been lost without the retainer line.. qued to the middle of the cut. The retainer line is visible at the beginning of the video:

tough to see on this one, but there is slack in the guy line which gets taunt at the very end of the fall:

Yup that's what I'm talking about. I use a portawrap and rope jack. Have thought about leaving it uncleated with
3 or 4 wraps but usually don't have a hand to tend it.

Funny how many times the tree is solid except where you need it. Also, too much tension on the pull line can
break a hinge especially if the pull is not perfectly aligned with the notch direction.

I like a beefier side rope, especially if it's not super high. Also it's less likely to break rolling down hill ;-)

I use true blue for natural crotch rigging and pulling smaller trees.

paul

 

[Daniel]

I use it for almost all pulling duties except for the heaviest of back leaners. If I think it's too light, I'll just put in a second and a third as needed before going with the bull lines, situationally dependent of course.

I would never set a pull or retainer line as low as shown. Higher is better... that's a lot less force and potential force on the rope

 

[hseII]

Does this count?

Wide canopy 36” DBH Pecan with visible forward lean & also side lean away from the camera.

7/8” Kraken connected to the track loader & gently persuaded to move away from the fence.

Other Fence on opposite side.

Happy repeat customer.

The west coasters have a term for it but triangle cut is what I most see it as.

Deterioration was observed at the base previously & PO did not want to have any more dropped limbs on his fence.


Sent from my iPhone using Tapatalk Pro

 

[shaddart]

looks pretty solid -extremely strong hinge wood on those pecans. Too bad it had to come down.