# Questions about learning the art of Felling



## timothykamp (Apr 29, 2009)

A quick bit of my history in the business - skip to the next paragraph for my questions if you don't want to read it.

I'm a 20 year old college student, studying engineering, but should be in business. I started out 4 or 5 years ago splitting wood on a borrowed logsplitter, and loved it. Now I have a a lot of my own tools, and recently started taking more and more trees down. I carry insurance on myself, but not on the work that I do. I do business only by word of mouth and referrals, and the first thing I say to a customer is that I have no insurance if I drop a tree on your house. Second,even without stepping foot on the property, I tell them that if I don't think I can do it, i have no issues with walking away from it and letting a professional do it. I like to think of myself as an amateur arborist of sorts. So, that said, over the past 3 years or so, I've probably dropped or trimmed around 200 trees. A good 80 or so were in a vacant lot, and a majority of the rest are in peoples yards far enough away from the house that I could drop them in any direction and still not hit the house. 
Initially, I base cut everything, let it fall, hoping that my 2 hour lesson from a professional arborist would be enough, and most of the time, it has. I've been safe for quite a while, and have had no accidents. I've been climbing trees without a rope almost since I could walk, and adding a chainsaw to the mix didnt seem like it would be too difficult. I've taken down a fair amount of pine and maples (easy to climb, easy to drop, etc) as well as a decent number of other species of various sizes. I love climbing, have used a construction harness and some good rope I found, and try to be as safe as possible. That said, I'm interested in learning more.

A few questions - 

I'm renting my first lift next month. I'll be trimming two huge old oaks (275 years old), and they are far enough from houses and anything that could be damaged that I think I can handle it. I believe it's a folding, 51' affair that is dropped off on site. Other than being careful that you don't hit yourself with a limb or run it into electrical lines, how is cutting from a lift different from cutting while you're climbing?

I have a big shagbark hickory tree (22"dbh) that has some swelling at the base. My arborist friend suggested that it could be rotten at the base. It's leaning slightly towards a shed, but has a clear fell path in almost any other direction. I've pulled trees over before, but never with a shed in the way. If I got a wire rope 3/4 of the way up, and used a ratchet puller to put a few thousand pounds of tension on it, what's the proper way to cut the hinge?
My hinge experience has been cut a deep V in the direction you want it to fall, and then come from the backside a few inches above the previous cut. I have been reading about people using dutch? cuts or something as well as making uneven notches and putting more on the tension or compression side. Some of this is intuitive, but short of going to full fledged school, where and what can I learn about this? Anyone have some good information other than pure experience on how to learn felling?


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## md_tree_dood (Apr 29, 2009)

Pictures are better than descriptions.


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## talloak (Apr 29, 2009)

Not be rude but who has taught you proper pruning and spending just a few hours with an arborist is not proper traing my suggeston is work with local tree service in your area for awhile get some know how under your belt .


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## ddhlakebound (Apr 29, 2009)

timothykamp said:


> A few questions -
> 
> I'm renting my first lift next month. I'll be trimming two huge old oaks (275 years old), and they are far enough from houses and anything that could be damaged that I think I can handle it. I believe it's a folding, 51' affair that is dropped off on site. Other than being careful that you don't hit yourself with a limb or run it into electrical lines, how is cutting from a lift different from cutting while you're climbing?
> 
> ...



It sounds as if you're setting up a couple of giant historic oak trees for a pre-demolition trim. 51' sounds just high enough to make a whole bunch of big wounds that will possibly be the death of the trees, and definately leave them looking like a couple historic hatracks. Please, for the sake of those trees, do alot of very fast learning about the amount and type of pruning that mature oaks can withstand, at the very least. Trimming mature trees is an art, and it takes a significant amount of time learning and experiencing to develop as an artist. 

Have you tried out the lift you intend to rent? Positioning is key to trimming from a lift (assuming you aquire the knowledge to trim properly), and many of those short rental lifts require firm, even ground, and move at a snails pace. So if it's not what you expect it to be, you'll spend much more time than you expected doing the job. 

If these trees are anywhere close to high voltage power, you need to learn limits of approach, and be able to do the job within those limitations. 

Your plan on the 22" hickory sounds like a great way to experience a dangerous barber chair from the batters box. There's a ton of info here on barber chair, and how it happens. Learn it, it's your ass on the line. 

No need for a steel line, you don't need nearly that much pull force, and steel has much less stretch than rope. That stretch is your friend. 

Even a few hundred pounds of pull 3/4 of the height of the tree will create a greatly compounded leverage force at the hinge. Create too much force, and somethings gotta give. You DON'T want to be there if it does. 

A few tips....

Get insured. Without it you're still liable for any damage or injury you cause. 

Get a proper saddle and climbing rope. Again, it's your ass on the line. Learn how to use them properly. How good is some "good rope you found"? What kind of rope is it? What makes you think it's good?

When you climb w/o a rope, how do you intend to get down if you're injured or cut?

Learn, learn, learn. There are way too many tree butchers out there.


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## DirtyDog (Apr 30, 2009)

I would reccomend buying a few videos and watching them before you touch another tree.
Using a lift requires controlled limbing of the tree, especially if the location of the lift is under where the branch will drop.
You should always wear a safety harness regardless of how safe you may feel. Spring effect of a tree can knock you right out. Also, springboard effect of an improperly dropped limb can catapult a hundred yards easily. 
Regardless if you tell customers you have no insurance....They can still sue you this day in age! Tree work is good money, but you need proper insurance.
An Applied Science in Engineering will make more money...easier...safer!
Don't let go of school. Run it till the end. The wood carving will still be here when you finish.


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## canopyboy (Apr 30, 2009)

DirtyDog said:


> An Applied Science in Engineering will make more money...easier...safer!
> Don't let go of school. Run it till the end. The wood carving will still be here when you finish.



I grew up with a saw in my hand and my dad running his own business. I stuck out engineering school thing and it was worth it. First, I have a day job where I make more money than my dad ever did. I don't sit at a desk that much, but am involved out in the field solving problems which is actually rather fulfilling. This leaves me in a position to make trees a small side business and hobby. Second, even if you're dead set on running your own tree business, an engineering education will give you a great understanding of the physics in tree work. Think about static loads and force calculations, dynamic loading and motions, the effects of geometry. Not to mention the fundamental understanding as to how a material like wood behaves as a structure. 

Stick out the school thing, it's worth it. In the meantime pay attention to what these other guys have posted. They aren't just giving you a hard time. They've seen too many people who have gotten in over their head, sometimes with some pretty tragic consequences. Just read through part of the injuries and fatalities forum.

Just another 2 cents on your way to a dollar.


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## D Mc (Apr 30, 2009)

ddhlakebound said:


> It sounds as if you're setting up a couple of giant historic oak trees for a pre-demolition trim. 51' sounds just high enough to make a whole bunch of big wounds that will possibly be the death of the trees, and definately leave them looking like a couple historic hatracks. Please, for the sake of those trees, do alot of very fast learning about the amount and type of pruning that mature oaks can withstand, at the very least. Trimming mature trees is an art, and it takes a significant amount of time learning and experiencing to develop as an artist.



Nicely put, ddh.

I initially skipped over this thread because there are many on this site very qualified for felling information. Clicked onto it this morning just for giggles to discover that you are talking about trimming. Not only trimming, but on two mature oak trees. 

This I have experience in. Nothing in your history that you have reported would indicate that you do. 

There is a lot you need to learn prior to working on those trees. This is something I feel very strongly about because I have seen the damage created from improper and/or inexperienced work. These are not the type of trees to experiment and learn on. Trees that live for many hundreds of years deserve a special place and consideration in our world. 

Dave


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## timothykamp (Apr 30, 2009)

OK - thanks.
On the old oaks - there are no powerlines anywhere close, and I will ONLY be removing dead wood and a few SMALL branches.
I'll definitely read up on barbers chair - 

Any suggestions on some good videos?

I do have legitimate climbing rope - now I need to find a good saddle.



> Originally Posted by Canopyboy
> I grew up with a saw in my hand and my dad running his own business. I stuck out engineering school thing and it was worth it. First, I have a day job where I make more money than my dad ever did. I don't sit at a desk that much, but am involved out in the field solving problems which is actually rather fulfilling. This leaves me in a position to make trees a small side business and hobby.



I'm going to stick out engineering school, but like canopyboy, I really love doing tree work because it lets me be outside, in the trees, etc. 

Dave, I think I understand what you mean about respecting a 275 y.o. tree. Thanks


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## MonkeyMan_812 (Apr 30, 2009)

Or buy yourself some books and study. Thats a good way to learn too! But dont cut on any 350 year old trees before your educated well!


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## TreEmergencyB (Apr 30, 2009)

um?......Oak Wilt anyone?


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## pdqdl (May 1, 2009)

A deep notch (more than 1/2) is one of the best ways to PREVENT barber-chair. You probably needn't worry about that. Sometimes I wonder if people on this site have ever really seen a barber-chair happen, or if they understand the reason.

Barber chair occurs when the compression force applied to the "fall" side plus the lift force on the holding side of the trunk creates a shear force in the middle of the trunk. When this force exceeds the sheer strength of the wood, the log splits rapidly and the flying trunk section has killed many fellers. When you make a deep notch, you remove compression wood, not holding wood, and the distance between the two areas is made shorter, thereby reducing the leverage applied to the trunk that creates the shear force. 

Conversely, simply back cutting a leaning tree is the very best way to create a barber-chair condition.

On the other hand, the deep notch method is not a terribly popular method. I use it extensively, but it exposes you to some risks that are impossible to recover from if you make a mistake.

If you should misjudge the tree, and it should fall (or blow down) the wrong direction, you have no remaining wood to hold the tree until you can correct the problem. It falls the wrong way, and you just created a big problem.

If you do a shallower notch, and then use ropes or wedges to send the tree over, you have some safety controls. If it "sets back" (goes the wrong way), then it just closes the gap in the back cut and sits there until you can pull it over.

Historically, when lumberjacks were cutting down trees with axes, the only method of directing the tree to fall was with the deep notch method. Wedges only work in a saw kerf. So there is nothing wrong with your approach, but you would do well to learn more about it.


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## ddhlakebound (May 1, 2009)

pdqdl said:


> A deep notch (more than 1/2) is one of the best ways to PREVENT barber-chair. You probably needn't worry about that. Sometimes I wonder if people on this site have ever really seen a barber-chair happen, or if they understand the reason.
> 
> Barber chair occurs when the compression force applied to the "fall" side plus the lift force on the holding side of the trunk creates a shear force in the middle of the trunk. When this force exceeds the sheer strength of the wood, the log splits rapidly and the flying trunk section has killed many fellers. When you make a deep notch, you remove compression wood, not holding wood, and the distance between the two areas is made shorter, thereby reducing the leverage applied to the trunk that creates the shear force.
> 
> Conversely, simply back cutting a leaning tree is the very best way to create a barber-chair condition.



No, I've never had a tree barber chair on me, and neither do I want to. All my experience with barber chairs is from stories, reading, and videos. I'd like to keep it that way. Sure, laying into a backcut with no notch is very likely to cause it...the OP's plan made it fairly possible too. 



> If I got a wire rope 3/4 of the way up, and used a ratchet puller to put a few thousand pounds of tension on it, what's the proper way to cut the hinge?
> My hinge experience has been cut a deep V in the direction you want it to fall, and then come from the backside a few inches above the previous cut.



So is it not true that too much pull force can be the cause of a barber chair? Can we trust that the OP's notch would be deep enough to remove all/most compression wood, and/or recoginze how much pull is too much, while using a steel cable?

Why is it that heavy leaners are notorious for barber chairing? Could it be because all that headweight leverages the compression and tension wood, much the same way that an overtensioned line would do?


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## Raymond (May 1, 2009)

Isn't starting a tree service at this time, 
like starting a real estate company?


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## pdqdl (May 6, 2009)

ddhlakebound said:


> ....
> 
> Why is it that heavy leaners are notorious for barber chairing? Could it be because all that headweight leverages the compression and tension wood, much the same way that an overtensioned line would do?



Head leaners are notorious for barber chair because it shifts the center of gravity to someplace off the stump. When you do a normal (small) open face cut, there is a huge shear force applied to the 1/2 of the trunk nearest the face cut. Since this is right on the easiest side of the log to split, once the pressure to split is greater than the resistance to splitting: CRACK!

The strength of the tree to resist that split gets less and less as you proceed through the cut. If the holding wood breaks off before the tree splits, you have a normal fall. If the holding wood is stronger than the resistance to splitting; well... now you have a problem.

So to answer the question you posed: Yes! Pulling a tree produces much the same load forces as a head leaner, hence the value of tensioning a pull rope a little to hold the tree, then adding pressure when the cut has advanced to where it should go over.

I personally have only had one barber-chair experience that I can remember: I was thinning and raising a silver maple, and decided to skip the hard work, I would just peel a 3" diameter arching horizontal branch by top cutting it and then cutting off the stub when I got lower in the tree. About 1/2 way through the cut, the branch violently split, throwing the cut 1/2 up in the air faster than I could have hoped to move aside. The split ran for about 4 feet, and the flying wood shot up at least 2-3 feet before the branch broke and began to descend. _If I had been above the branch, it could easily have knocked out some teeth_. Fortunately, I was reaching out to make that cut, and nothing amiss happened, except for my heightened awareness of how barber-chair can happen.

If that had happened with a 1000 lb section of trunk, it could have blasted the feller into eternity.


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## canopyboy (May 7, 2009)

Ok, I can't help chiming in from an engineering perspective here. Think of a tree as a beam. When you put a moment (force at a distance or torque) on a cantilevered beam, you have the same thing as a pulled or leaning tree (or a branch for that matter). The outermost fibers on the back side are under tension, and the outermost on the front side are in compression. Most of you all understand this. Once you get to the wood at middle, you're at the balance point and this wood is basically in shear, keeping the tension and compression sides apart. The farther the outermost tension fibers are from the compression fibers on the other side, the lower the actual tension/compression stress in those fibers are and the stiffer the beam. This is why I-beams work the way they do, all the tension and compression is picked up in the flanges, and the web in the middle keeps the flanges apart. In a square beam section, the strength and stiffness goes up with this distance between the outermost fibers cubed. A round section is close to cubed. I won't bore you with moment of inertia calculations.

But back to barber chair.... As soon as you start to notch the compression side and sever the tension side of a tree with a large moment on it, you're reducing this distance and these outer layer tensions go way up. The result is that the remaining wood starts to flex. The wood on the back that has already been cut wants to stay straight, while the ones left in your (still large) hinge are being force to bend. Now the bonds between the wood fibers at the leading edge of your backcut are being pulled apart. If this bond holds, everything is fine until the hinge itself finally starts to go and the tree falls as designed. If however, there is simply too much force (gravity or pull line) bring the tree over and the hinge isn't ready to go, the fibers separate just like splitting firewood. Sometimes this happens fast like breaking glass, and sometimes quite slow with lots of warning noise. Either way it's makes your heart speed up.

I've had it happen on a large oak back when I was young and stupid and had a friend pulling on it with a truck, and I've also had it happen on a couple of heavy leaners where I didn't have much of a choice except proceed carefully and exit quickly (and use someone else's saw....). If you want to fully understand barberchair, pick something small that will split easy and put a lot of tension on it. If you can make the barberchair happen on purpose with a 3-4" sapling, you'll have a much improved understanding of how to prevent it when the consequences are a bit more severe.

Finally, one of the reasons a Dutchman is notorious for causing barber chair comes back to the distance between the outer fibers of your beam section again. As the tree first starts to go, only the hinge is acting, and this distance is only the thickness of your hinge. But after a few degrees of fall, the kerf at the dutchman closes. Now the edge of the dutchman becomes the compression side of your beam, while your hinge is in full tension. Your distance just went way up and now the tree has some momentum. Three things can happen: (1) the hinge fibers simply yield to the large tensile stress and break. The tree is now free of the stump. (Doing this on one side is a method of turning the tree on its way down). (2) The hinge fibers hold, and the tree stops falling. Now you have a dangerous situation and you have to carefully trip the cut the rest of the way. (3) Or you have the large moment from the tree's momentum and new lean with a large effective hinge section creating what I described above -- Barberchair!

If anyone doesn't understand what I'm saying but wants to, let me know and I can break it down with pictures and diagrams. To those who are annoyed at the long post, my apologies. But the licensed structural engineer in me can't help myself. Besides, the better your understanding of the physics involved, the safer and more efficient you can be.


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## Tree Pig (May 7, 2009)

Heavy lean I usually bore cut the tree. I just dropped a 50' very dead large oak. The tree was totally dead and leaning the wrong way. After snapping the top half off with a rope I dropped the rest. Three quarters of the outer and inner material (bark, cambium, heartwood) were all decaying. The only strong and supporting material luckily enough was were I needed to make the back cut. Cut a nice notch, bore cut a good hinge removing wood from there back to a good trigger. now remove your saw and place it in a safe spot. double check your escape route insert wedge two or three taps on the wedge with felling axe and she started to go. Drop the axe and gain distance until your sure its going as planned.

I have seen notches cut too deep on leaners cause it to crack and barber chair in the middle of that deep notch. I have never had one barer chair cutting leaners in this way (knocks on wood and crosses fingers)


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## pdqdl (May 8, 2009)

canopyboy said:


> Ok, I can't help chiming in from an engineering perspective here. ....
> 
> If anyone doesn't understand what I'm saying but wants to, let me know and I can break it down with pictures and diagrams. To those who are annoyed at the long post, my apologies. But the licensed structural engineer in me can't help myself. Besides, the better your understanding of the physics involved, the safer and more efficient you can be.



I understand completely, but I'd love to see your pictures. So far, I have never come across good drawings that really teach the why and how of Barber-chair events. 

They might become Arborist Site classics if they really teach the unwary how it works.


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## canopyboy (May 8, 2009)

pdqdl said:


> I understand completely, but I'd love to see your pictures. So far, I have never come across good drawings that really teach the why and how of Barber-chair events.
> 
> They might become Arborist Site classics if they really teach the unwary how it works.



Let me put it together and I'll post it in a new thread here under 101. If people like it and it becomes a classic, so much the better.


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## Ghillie (May 8, 2009)

canopyboy said:


> Let me put it together and I'll post it in a new thread here under 101. If people like it and it becomes a classic, so much the better.



I will definately read it over. I am a sucker for technical data.


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## True Blue Sam (May 8, 2009)

http://3.bp.blogspot.com/_HV-DGQIDrWg/SKD8t9MlEFI/AAAAAAAAA3o/sWqF01RJh1g/s1600-h/IMG_4237.JPG

http://bp3.blogger.com/_HV-DGQIDrWg/R2nAZZjblDI/AAAAAAAAAL0/JuGF6AUAtoU/s1600-h/Barberchair.jpg


http://bp0.blogger.com/_HV-DGQIDrWg/R2kiUpjblCI/AAAAAAAAALs/WiR_sLSJbuo/s1600-h/DeathBarberChairMvc-007f.jpg
Here are some barber chair examples I have seen. The sassafras pole was cut from the leaning side with a single cut, no real opening, then back cut. It stopped when it ran into another tree, and the cutter did not have his face knocked off. I knew a guy who cut a hickory this way, and he had his chest caved in and died in the woods.

The second one is a tree a farmer cut only from the back side, with a steep angle "so the stump could push it over." He was not hurt, but he didn't clean this mess up for quite some time.

The bottom photo is a pecan cut near Golden Gate, IL a few years ago. It was severed from left to right, to the spring pole it hoisted itself on. The tree tipped to the right, the crown ran into another tree, then spun counter-clockwise on the springpole, and hit the logger in the back of the head as he tried to get away. He was killed 12 feet from the stump. His brother cut the bottom of the spring pole off, and it is lying next to the stump with the rest of the springpole behind it. 

You see a few of these and you make sure that you do your setups right when you cut into a tree.


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## canopyboy (May 8, 2009)

Some good example pictures. And your story about the last one just goes to show how many things can go wrong with something that seems simple if you don't really know better.

We like to preach leave it to the professionals, but how many of you learned a lot of your "knowledge and wisdom" by doing something you shouldn't have and were just lucky enough to be able to live and learn from it....? 

I haven't needed that luck as much in recent years, but when I look back at my childhood and early twenties even, I'm often surprised I've made it this far.


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## Ghillie (May 8, 2009)

canopyboy said:


> Some good example pictures. And your story about the last one just goes to show how many things can go wrong with something that seems simple if you don't really know better.
> 
> We like to preach leave it to the professionals, but how many of you learned a lot of your "knowledge and wisdom" by doing something you shouldn't have and were just lucky enough to be able to live and learn from it....?
> 
> I haven't needed that luck as much in recent years, but when I look back at my childhood and early twenties even, I'm often surprised I've made it this far.



If I had known I was going to live this long, I would have taken better care of myself!


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## WetBehindtheEar (May 9, 2009)

*Ok..*

GREAT topic.

Not a pro. Also an engineer (mechanical & biomedical).

Been helping FIL farmer clear fences for the last two years or so.

This may be controversial but the Game of Logging classes I took really emphasized the need to set up the notch properly - spend more time 'aiming' your fall than actually cutting.

They also emphasized the value of the plunge back cut. It defines your hinge properly before all of the holding wood is gone.

In the photos provided, I saw no evidence of a really decent notch. The first description said there wasn't a notch. The second and third didn't comment on it. Did my inexperienced eye miss something?

Thanks for the discussion.


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## True Blue Sam (May 9, 2009)

Good Eye! The second one had no notch, just a back cut. If you look closely a the pecan you will see a small notch cut out lying to the left of the stump. The logger took out this notch, but did not leave a hinge behind it. I think he wanted the tree to go to your left, but it was weighted to the right and was not properly set up or wedged. Gravity and the physical limitations of the wood took over. 

I am glad you have had the GOL course. It will keep you safe. OSHA lists the open face method, the conventional cut (45 degree opening), and the Humboldt undercut as the only methods they approve. I use the open face, and bore cut for most trees I cut because it allows me to set up the tree, and check for pedestrians that may have wandered in before I turn it loose. I can also make a quicker getaway when my saw is not buried in the tree.


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## canopyboy (May 9, 2009)

Ghillie said:


> If I had known I was going to live this long, I would have taken better care of myself!



Amen Brother Ghilllie...


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## pdqdl (May 9, 2009)

That's funny...I always thought I was indestructible, and would last forever. 

That was when I was much younger, of course.


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## WetBehindtheEar (May 9, 2009)

True Blue Sam said:


> I am glad you have had the GOL course. It will keep you safe. OSHA lists the open face method, the conventional cut (45 degree opening), and the Humboldt undercut as the only methods they approve. I use the open face, and bore cut for most trees I cut because it allows me to set up the tree, and check for pedestrians that may have wandered in before I turn it loose. I can also make a quicker getaway when my saw is not buried in the tree.



Thanks - I think I might like to re-take the course. It's a bit pricey but I KNOW I didn't get everything I wanted to get out of it. They didn't explain some things as well as I would have liked regarding how much lean you can overcome. 

I agree on being able to get the h*ll out of dodge quickly - but my philosophy has always been, "in the end, it's just a bunch of metal, gears, plastic, and some liquids... it can be replaced." 

I have a healthy respect (maybe fear?) for what the saw can do and ALSO what that tree can do once it isn't attached to its roots anymore.


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## Raymond (May 9, 2009)

WetBehindtheEar said:


> Thanks - I think I might like to re-take the course. It's a bit pricey but I KNOW I didn't get everything I wanted to get out of it. They didn't explain some things as well as I would have liked regarding how much lean you can overcome.
> 
> I agree on being able to get the h*ll out of dodge quickly - but my philosophy has always been, "in the end, it's just a bunch of metal, gears, plastic, and some liquids... it can be replaced."
> 
> I have a healthy respect (maybe fear?) for what the saw can do and ALSO what that tree can do once it isn't attached to its roots anymore.


Just one step at a time Wet Ears. And before you know it, 
you're at home looking at the bills the mailman brought you that day.


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## Tree Pig (May 10, 2009)

Raymond said:


> Just one step at a time Wet Ears. And before you know it,
> you're at home looking at the bills the mailman brought you that day.



yep but keep plugging away and your choosing what check to cash to pay them bills, so you dont have to spend all that cash in your pocket.


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## smokechase II (May 10, 2009)

*Caveat*

*"I am glad you have had the GOL course. It will keep you safe. OSHA lists the open face method, the conventional cut (45 degree opening), and the Humboldt undercut as the only methods they approve. I use the open face, and bore cut for most trees I cut because it allows me to set up the tree, and check for pedestrians that may have wandered in before I turn it loose. I can also make a quicker getaway when my saw is not buried in the tree."*

=============

Just a quick comment on not getting locked into any one method:

In the world I come from; dead rotten wood and in recent or still burning wood the boring back cuts are usually to be avoided.

The reason - *to keep you safe*.

Collapsing trees and pinched bars etc.

May I suggest acquiring a variety of techniques and then selecting the safest on a tree by tree basis..................


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## TheTreeSpyder (May 10, 2009)

"Measure twice, cut once" applies hear. MTL Dutch Siding shows some barberchair theory.

It also goes on to show how these forces could be trained after a decade or so of experience. But, for the most part, this dutch siding should just show here, that these small changes in face/hinge/backcut are very powerful mechanical commands. Whereby a small change, can give an immense change.

It should also be noted how crossed/bypassed facecuts can give a push (vs. a tensioned pull from hinge) in face. This push is more powerfull if the close is from the floor cut in a conventional hinge bypassing the upper cut; whereby the push is up the fiber column inline/unforgiving. But, if the early close is from the upper cut bypassing the floor, the pressure is more across the fiber column, so the fibers can flex more forgivingly.

Relief as the equal and opposite of force, is as important. The across fiber push gives more relief,s o is less powerful and less dangerous. Also, then too, a full 'dutch' across the face gives no place to go, no relief, so can 'shatter' or make a 'split decision' and the spar is violated as the rush of force forward is blocked forward, and to sides. On the other hand, blocking/dutching just 1 side of face, offers the other side as relief, for force to flow, and not build as much!!

These things work in our massive example of felling, but also in climbing and bucking. Mostly hear, i'd say, to L-earn why not to use them, to not use them purpose-fully. If you do dabble, try in bucking, or climbing when feeling confident; though you can still get into trouble if you person-ally call that wrong.

These are simple mechanics, but set to super loading, so everything matters, each tweak can alter the stack of multipliers immensely, thus altering the output!


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