Getting a tree to drift during fall by thinning the hinge.

[Phil]

August Hunicke posted a new video to the YouTube.

Pretty short video and he gave a pretty thorough educational style explanation why he was doing and making the choices he was. I usually agree with pretty much everything he says and just passively watch guys like him and Reg, enjoy the content and pick up some occasional insights and techniques. If you skip to 13:17 in the video, he shows the hinge post-fall and explains how he did a bit of last minute cutting on the hinge to steer the tree, allowing it to drift a bit more into the available space. I guess the short question from me is: How can that possibly work? It does not make sense to me that you can create side drift by thinning the hinge when gravity is in control of the trees movement, unless you do something like a dutchman/bypass or something other than a solid, clean hinge across the stump. At the moment he thinned the hinge, the pull rope was likely slack, and without physically pushing/pulling the canopy to the side, or the canopy of another tree to pushing the falling tree as it moves past, lateral drift won't happen until the notch closes and the hinge breaks. He even made a very wide open notch to allow the hinge to hold for as long as possible and keep the butt of the tree close to the stump. The hinge and the direction of the notch is what steers the tree. As long as the hinge is intact, how can there be drift? I mentioned this in the comments section and he responded politely defending his choice and explanation. I am aware there is a lot of nuance to this job, but I'm having a tough time with this one. I think the tree went were he aimed it from the get go. Thoughts from the group? Am I really just too simplistic with my thinking on this?

 

[Stumpsprouts]

August Hunicke posted a new video to the YouTube.

Pretty short video and he gave a pretty thorough educational style explanation why he was doing and making the choices he was. I usually agree with pretty much everything he says and just passively watch guys like him and Reg, enjoy the content and pick up some occasional insights and techniques. If you skip to 13:17 in the video, he shows the hinge post-fall and explains how he did a bit of last minute cutting on the hinge to steer the tree, allowing it to drift a bit more into the available space. I guess the short question from me is: How can that possibly work? It does not make sense to me that you can create side drift by thinning the hinge when gravity is in control of the trees movement, unless you do something like a dutchman/bypass or something other than a solid, clean hinge across the stump. At the moment he thinned the hinge, the pull rope was likely slack, and without physically pushing/pulling the canopy to the side, or the canopy of another tree to pushing the falling tree as it moves past, lateral drift won't happen until the notch closes and the hinge breaks. He even made a very wide open notch to allow the hinge to hold for as long as possible and keep the butt of the tree close to the stump. The hinge and the direction of the notch is what steers the tree. As long as the hinge is intact, how can there be drift? I mentioned this in the comments section and he responded politely defending his choice and explanation. I am aware there is a lot of nuance to this job, but I'm having a tough time with this one. I think the tree went were he aimed it from the get go. Thoughts from the group? Am I really just too simplistic with my thinking on this?

Hey Phil, I do this from time to time and all I can say is it does work. Unfortunately I don’t have a great explanation to you as to why. I think it’s more about the fibers of what remains in the hinge offering some resistance and creating a little bit of an influence in the direction you’re adjusting for.

 

[Serf Life]

Likewise do this, but not always with the desired effect or amount of turn. For example used when the stem wants to go between two tree tops, then turn a bit to miss a farther/smaller one in its path. Straight up and down stem and limber fibers helps.

 

[Dan Thornton]

It makes sense to me that the "aim" of a hinge should be near the centerline of the hinge, not the front of the hinge, since the front half compresses, the back half is under tension, and the middle is where it acts as a fulcrum. But ...

But my experience says the front of the notch controls the direction. For instance, if I mess up and the tree falls before I have squared off the back cut, the tree always follows the aim of the notch, not the "aim" of the back cut, nor something in between. I count on this when I purposely keep the hinge much fatter on the side away from a house (usually supplemented by a safety line), the tree falls following the aim of the front of the hinge, never the back of the hinge.

I keep hearing people say this technique sometimes helps, or it depends on the wood ... so I never plan to do it because I like sure things. Plus, I try to get away from the stump as soon as possible instead of nibbling on an actively bending hinge.

 

[Matias]

I feel like it works better on stringy wood that like to hold on all the way through.

 

[evo]

For trees that don’t have brittle holding it works great. I’ve had guyed side leaners swing well by using this. Infact so well the guy rope slacks off.

Remember the corners do most of the work and the heartwood is essentially filler (that might be a bit over simplified heart wood does have holding).

A good faller that says with it can steer a tree down, a little to the left and then a little to the right. Sometimes it’s as extreme as cutting the corner off the hinge as the tree starts moving.

Sometimes this is used to get the tree to spin clockwise or counter clockwise which can avoid it getting hung up as it brushes other trees.

 

[Matias]

I suspect the effect is relative to the overall mass and length of the tree, so we would see it more clearly out in big tree country

 

[rico]

Timber fallers have been standing in the pocket and caressing their hinge to help finesse trees into their lay since the dawn of time. Why? Because it works.

 

[Phil]

Sometimes it’s as extreme as cutting the corner off the hinge as the tree starts moving.

Sometimes this is used to get the tree to spin clockwise or counter clockwise which can avoid it getting hung up as it brushes other trees.

This I 100% agree with and understand. I have done this may times to utilize the momentum of the falling tree to roll off another when I was expecting crown interference. I would usually cut through the desired hinge corner before the tree started falling though, not while it was mid fall, and the one corner would be completely severed so as to allow the butt to physically roll off the initial hinge line. If the hinge is fully intact through the fall, and there is no tree canopy to interfere and push the falling tree, what mechanism magically steers the tree?

Timber fallers have been standing in the pocket and caressing their hinge to help finesse trees into their lay since the dawn of time. Why? Because it works.

Why does it work? What are the mechanics of the fiber that allow a tree to drift without an external force on the crown/stem while a hinge is still fully intact across its entire length? What steering is gained that can't be achieved by aiming your notch ever so slightly in the direction you are steering the tree with the corner shaving? I would wager video is a tough medium to showcase this steering effect. It might be one of those things you need to be there to see to fully appreciate its effect. I would also wager, the taller the tree, the more this steering effect is perceived.

I generally follow the logic put forth by @Dan Thornton. Regardless of this technique working, I don't like being at the stump, actively cutting ripping fibers while the tree is falling. Most tree felling injuries and fatalities happen within 5' of the stump within the first 15 second of the tree falling. What am I gaining vs what am I risking?

At the end of the day I'm trying to understand the mechanics behind this. Felling is a physics problem with many variables. Here we are saying the single act of releasing some extra fiber does this steering thing. The tree drifted because I thinned a corner of the hinge. Why? Can we define what exactly this single act act of hinge thinning is doing?

 

[Dan Thornton]

Timber fallers have been standing in the pocket and caressing their hinge to help finesse trees into their lay since the dawn of time. Why? Because it works.

I am in awe of the things the timber fallers can do. I generally climb and either prune or dismantle, which is the specialty I want. Sure would be great to get a job just felling a hundred trees with no targets. Might be good at some of the finesse skills after that.

 

[CRTCNH]

Really interesting question @Phil and interested to read responses.

I’m no physics wiz by any means. But one thing that does come to mind - if I stand up and proceed to lean forward until I fall, I will fall in the direction I’m facing. However if I stand up, and someone is holding my left ankle as I lean forward into a fall, I would fall towards the left/or roll (ie - cutting one side of a hinge thinner to create this “roll”). You mentioned “external force” if I leave more holding wood on one side, I’d consider that an internal force, but a force nonetheless.

I could be totally wrong here but it was just something that came to mind. Again, great question and interested to follow this thread.

Pat

 

[Flying~Squirrel]

The intact fibers are what hold the tree up, gravity pulls the tree down. If there are more fibers on the left side of the hinge, the tree is more resistant to falling, and falls slower. The right sided gives into gravity more easily, allowing it to fall faster. Since the right side is moving faster than the left, the whole thing moves left, just like the spoke of a wheel.

If this technique works (which I am agnostic about), it works mostly early in the tree's movement. Once the potential energy starts releasing into kinetic, the resistance offered by the fibers diminishes rapidly. There would be a critical window where the resistance is significantly high enough compared the the kinetic energy to have a practical effect.

What I am less agnostic about, is using a non parallel hinge to encourage a tree to go at an angle away from its direct lean. Not the case of a change in direction mid fall, but to swing sideway in a straight line.

 

[SeanRuel]

A PNW faller I worked with said his old time mentor made him back cut his first several trees with a misery whip/crosscut saw. All simple up and down Dougs, to watch how taking material of the back of the hinge moves the tree. The old-timer thought chainsaws cut too fast for new fallers to watch/notice the side to side influence

Here's your excuse to buy a crosscut saw I guess?

 

[Phil]

Here's your excuse to buy a crosscut saw I guess?

Lol ... A younger me might entertain this notion. The current me, not so much.

It is an interesting point to identify the cutting speeds between cross cuts and chainsaws as a divider in learning felling cut nuance.

 

[rico]

The intact fibers are what hold the tree up, gravity pulls the tree down. If there are more fibers on the left side of the hinge, the tree is more resistant to falling, and falls slower. The right sided gives into gravity more easily, allowing it to fall faster. Since the right side is moving faster than the left, the whole thing moves left, just like the spoke of a wheel.

If this technique works (which I am agnostic about), it works mostly early in the tree's movement. Once the potential energy starts releasing into kinetic, the resistance offered by the fibers diminishes rapidly. There would be a critical window where the resistance is significantly high enough compared the the kinetic energy to have a practical effect.

What I am less agnostic about, is using a non parallel hinge to encourage a tree to go at an angle away from its direct lean. Not the case of a change in direction mid fall, but to swing sideway in a straight line.

Have you ever stood at the stump of a 150-200 footer and watched the effects that massaging your hinge can have on fine tuning your lay (the difference between an adequate faller and a great faller)? I am a adequate faller at best, but have been blessed to have worked around some of the best. Inches matter when you are are dealing with wood as valuable and tender as redwood and watching the accuracy of a great faller is something to behold.

 

[Flying~Squirrel]

Have you ever stood at the stump of a 150-200 footer and watched the effects that massaging your hinge can have on fine tuning your lay (the difference between an adequate faller and a great faller)? I am a adequate faller at best, but have been blessed to have worked around some of the best. Inches matter when you are are dealing with wood as valuable and tender as redwood and watching the accuracy of a great faller is something to behold.

Yeah actually I have. Seen some misses, too, despite massaging. Adequacy, I guess.

 

[Phil]

Have you ever stood at the stump of a 150-200 footer and watched the effects that massaging your hinge can have on fine tuning your lay

I have not. Which is one of the reasons I like watching guys like August and Reg. Most of the concepts and techniques I see I am familiar with. the fact they are cutting in a different region, with different trees and their characteristics is where I find the opportunity to grow beyond my local work experience bubble.

 

[Phil]

Adequacy, I guess.

Or there are other variables contributing to a perceived drift and we just anecdotally attribute it to our cutting. Slight wind, for example, on a 200' tree could move the top a dozen or more feet. Also the sail effect as a tree falls and it's branches catch wind. That effect could push the top while we think our cutting is the thing causing the move. I'm playing devil's advocate with this since no one has definitively put forth a scientific explanation.

 

[Tom Dunlap]

@Phil

You just said what I;ve been struggling with. Very clear.

There are so many uncontrollable variables in felling full canopy trees or even just crowns that have had brush removed.

If arbos were only cutting down single stems we might find a way to account for those variables.

Well said.

 

[evo]

Or there are other variables contributing to a perceived drift and we just anecdotally attribute it to our cutting. Slight wind, for example, on a 200' tree could move the top a dozen or more feet. Also the sail effect as a tree falls and its branches catch wind. That effect could push the top while we think our cutting is the thing causing the move. I'm playing devil's advocate with this since no one has definitively put forth a scientific explanation.

It really comes down to experience. Who in the hell comes up with putting a face cut on the topside of a limb and under cut on the bottom? Those who do more climbing work and arborists.
Not saying fallers don’t come up with some whacked out stuff.
But who here has block faced a top? While I consider myself a pretty damn half decent faller I don’t really use block faces other than in a modified face. Meaning a few inches in where the apex of the notch is. That suits my needs but I rarely use that aloft.

Back to the original topic, I do nibble my back cuts nearly on every tree it can aloft or not. It’s experience that tells you situation and species it will work better for. For instance bigleaf maple can be one of the most unpredictable in my area when dismantling. Experience tells me that nibbling swings might not work reliably and I should have a rope on it. Once I have a rope on it it’s mitigated and I’ll nimble. Works sometimes..

Play around with it, little things can get a limb to roll into the rigging or initiate enough of a roll or drift to avoid hanging up on a lower limb.