Barber Chair Take Away...

[Warren]

Managed to "barber chair" my first tree yesterday afternoon.  Good news is I was standing 20 ft away on my escape path when it split, and, the tree came all the way down on it's own.  Afterwards, I was looking over the stump and noticed that I did not hold my bar level on the face cut, or the back cut.  Apparently let the tip drop on both.  AS a result, on the back cut, the tip of my bar was actually 2" below the plane of the face cut.  I am assuming this "poor form" on my part caused the barber chair. 

The tree also had a definite lean in the direction I was felling it.  Would the lean have contributed to a barber chair if I had done everything right on my part ?

Looking for advise and correction from the professionals to prevent this in the future.  All help greatly appreciated.

Thx,  Warren

[Gary_C]

Dropping the tip of your bar would not by itself cause a barberchair. On trees that are leaners in the direction of the fall it is important that you bore cut and establish the width of your hinge before you finish the back cut.

Other than that , a too narrow opening on the face could be a problem that can cause a barberchair.

[Reddog]

I am with Gary on this one.
Hinge to thick or face opening to small.

[Kevin]

If your back cut is made too slow on a leaning tree it can split out.
Do you have a picture of the stump?

[Ianab]

It's probably a combination of the tree leaning and your cut not being perfect.

If the force of the leaning tree becomes greater then the strength holding the log together and the hinge is too thick / not formed correctly then the tree splits. Leaners can barbercair with conventional cutting, even if you do everything right.

I allways use a bore cut on leaning trees, lets you set up the hinge wood properly BEFORE the holding strap is cut and the tree starts to move. It's a much safer cut in that situation.

Cheers

Ian

[maple flats]

I'm with Gary_C and Ianab. On a leaner especially you must learn to bore cut before you finish the back cut. Do the face cut with a WIDE angle (70 degrees+) and then with the attack part of the saw bar start a plunge cut and when in far enough to prevent kick back go straight into and thru to form your hinge. The face cut must be clean or fix it before you plunge cut. Make the hinge 10% of the diameter. If your bar is not long enough you can either narrow the trunk on one or both sides, and/ or plunge from both. when you make the plunge do not be too close to the hinge, but rather go thru and then work to the hinge. With practice it becomes easier but check both sides to verify hinge size. From there with a leaner just cut towards the back of the tree (opposite the face cut side) and as soon as you cut thru look to verify correct fall and head immediately to your pre planned escape route. If you are not cutting a leaner do the same until the final cut. Here a wedge or 2 may be needed. If you are pushing a tree against it's lean you might need to stack wedges to get it to fall, have enough plastic wedges on hand before you start. And no matter how good you get at it never forget to be extra careful, all tree falling is dangerous. Wear your safety gear at all times.

[Dale Hatfield]

[

From there with a leaner just cut towards the back of the tree (opposite the face cut side) and as soon as you cut thru look to verify correct fall and head immediately to your pre planned escape route. If you are not cutting a leaner do the same until the final cut.

Cutting from the inside out on a leaner can be a good way to take a ride or watch your saw leave you and get planted.
When you cut from the inside out. On a foward leaner,The wood behind the bar can break away from the ground traping  saw. If their is a root swell on the back side .It can tare up and out of the ground. When this happens you can be flipped over by the uplift of root and ground.
Best way is to make the open face notch.
Establish hinge of proper length and thickness.Based DIB.
Once hinge is made cut back  a ways  leaving holding wood in the back.
Once your sure impact area is clear, Know your escape route.
Finish cut from the back side towards the hinge.
Once you  start dont stop till she pops loose and escape.
Dale

[arojay]

I am with Dale Hatfield on this.  I have heard from some guys who say cut from the inside all of the way back.  I have tried it and found some unpleasant surprises take place and quickly.  Finishing the felling cut from the backside seems to allow you better control.

[sawguy21]

I wondered about that too. I had never heard about cutting from the inside out, I place my wedges and work from the back of the tree.

[Gary_C]

This is the way I cut most all large trees.



At this point I have finished cutting towards the back of the tree and set my wedges. Now I will cut from the back till the tree starts to fall, or if it does not fall, I will drive the wedges in till it does fall.

[Larry]

Well lets see....nice even hinge with proper angle/width, no dutchman, no splinter pull over 3", and tree within 3' of stump.  Plus bonus points for not leaving any money on the stump.

Me thinks Gary knows how to cut trees...and a textbook photo of how to do it correctly.

[maple flats]

I have cut leaners from the inside out so the holding wood has the most hold and so far have had not problems ever, BUT if you want you can then cut from the back side. Either way make a quick retreat as the tree starts to fall. If the saw does start to go with the tree at anytime, which I have not had happen, let go and get out of there, even a pricey saw is cheaper than a funeral or major hospital time. The Gary_C pictures do show a very good face cut and hinge. If leaning I prefer cutting from inside back but if rather straight or slight lean I do it from the back and may even plunge in to place a wedge and then cut from the side towards the wedge on each side, compression side first then tension side.

[Kevin]

Another area for concern is the wood under the hinge, if it happens to extend down over a root then it could stall the tree also causing it to split out.
Cutting into the stump below the hinge will reduce the chance of this happening.

[Warren]

Folks,   I apprecaite all of the input.  Reading over the comments, there were several things I could have done better:

1) The front cut was about 5" deep on a 21" stump.  I thought that should have been deep enough. BUT, there was an irregular shape in that area, so the hinge was only about 10" wide.  (looked kinda like Gary's last picture, on the side opposite his hinge)

2) I cut straight in from the back and stopped/retreated as soon as I saw movement.  This left a very thick hinge when it did actually go over (in slow motion).

In retrospect I should have cut deeper to create a wider hinge.  And probably should have stayed on the saw a little longer to reduce the hinge thickness before retreating.  In addition to keeping the bar level so all of the cuts lined up better.

Gary,  most excellent pictures.  I have attempted the plunge cut, pull out, cut the back strap to release before, but have pinched the saw several times.  Your pix with the wedges are very helpful to better understand how to make it work properly...

Kevin, You are correct. I have had that section of root structure pull/split out before.

My number one goal is to be safe and come home in one piece.  Close behind is not to waste wood.  While not a big tree by most standards, I was pretty disappointed when I saw the split and realized the amount of wood wasted...

I appreciate everyones comments and willingness to share.  This is part of what makes the Forestry Forum a great place on the 'net.

Warren

[Qweaver]

I'm pulling on almost every tree that I fell.  I use the tractor for the small ones and the dozer for the big ones.  The few minutes that it takes to attach the chain and cable is time well spent in my opinion.

[WDH]

This is the way I cut most all large trees.

How do you keep from cutting into the wedge when you start the back cut?  I want to try this technique, and I was wondering after the plunge cut to form the hinge, how do you cut to place wedges without cutting them as you complete the back cut?

[beenthere]

Warren
You have initiated a good tree felling discussion.
I'd suggest that you would enjoy taking a GOL course (Game of Logging) to learn some of the fine techniques of reading the tree and placing the cuts as have been described in this thread.
Each tree may be a bit different, and some can pull tricks on the person who tries to do them all with the same basic technique.  After GOL, I plunge cut most all the time. After the plunge cut, saw to make the best possible hinge, then back cut to leave the holding wood and place for the plastic wedge (or two). Then when all clear, everything checked, make the cut on the holding wood to release the tree. Basic, but generally seems to work real good.

I rarely hook a cable to pull trees over, as the terrain is not conducive to do that, and someone pulling too soon, or too late, just seems to lead to additional problems (too soon = barberchair). The communication to a second person around the tree adds another safety factor to consider. But yard trees, that is different IMO.

[Gary_C]

Another area for concern is the wood under the hinge, if it happens to extend down over a root then it could stall the tree also causing it to split out.
Cutting into the stump below the hinge will reduce the chance of this happening.

The way I was taught, the hinge and notch opening must be formed carefully so the hinge wood will remain in control  through most but not all of the fall and most likely break from bending and not tension. Overcutting into the hinge or in any other way compromizing the hinge wood is not advisable. I do cut away the sides sometimes if there is a lot of butt flare as in this picture.

How do you keep from cutting into the wedge when you start the back cut?  I want to try this technique, and I was wondering after the plunge cut to form the hinge, how do you cut to place wedges without cutting them as you complete the back cut?

That is why I use cheap plastic wedges. Sometimes I do cut into the wedges.  ;D

[Kevin]

so the hinge wood will remain in control  through most but not all of the fall

That will depend on whether you want the tree to stay on the stump.

If the tree is leaning it probably doesn't need wedging unless the intent is to lift and turn the tree.

The problem with large leaning trees is they want to split out due to the tension within the tree before the hinge is set up.
On a standard back cut you have to keep up with that tension wood to keep the tree from splitting out and that requires full throttle and fast cutting up to but not compromising the hinge wood.

I agree boring is best but boring wasn't done on this tree so why did it barber chair?

[DanG]

In cutting trees, like most other things, us amateurs face some problems that the pros just don't have.  One of those things is holding the saw level.  That seems to be one of those things that comes with experience.  Don't be ashamed to cheat a little bit and make a level mark of some kind to get you started off right.  You can use chalk or spray paint, but I usually just use the saw to just scratch the bark where I want the cut to go.  My back and knees don't bend as well as they used to, so these marks help me a lot.  Also, I will ask my helper to tell me if the saw is level before I start a cut.

I put a rope or cable in most of the bigger ones and use the truck winch.  Many times, I put a snatch block on another tree so the truck is close enough for me to run the winch myself with a long control cable.  I just keep the cable almost tight, so it doesn't have any effect unless I need it.  Most of the time I don't, but it is there if I do.

[beenthere]

..............
I agree boring is best but boring wasn't done on this tree so why did it barber chair?

The question answers itself.  Boring wasn't done on this tree, so it did barber chair.   

Or did I misread the question.   :

And I mark the tree bark like DanG   

[Kevin]

Boring would be a preventive measure as would cutting a V hinge or boring the hinge etc. but from this ...

I cut straight in from the back and stopped/retreated as soon as I saw movement.  This left a very thick hinge when it did actually go over (in slow motion).

The hinge was too thick at the time the felling cut was stopped.
If the cut continued and kept up to the breaking fibers the tree most likely would not have split out causing the barber chair.
It was too late to bore the tree after the back cut was made, the only thing that would have saved this tree was to commit to the cut up to the hinge wood but if you stop prematurely you better get out of there.

[Dodgy Loner]

I've never tried to fell a tree using a boring cut, and I'm having a hard time envisioning how this would be done without experiencing kickback.  Does anyone happen to have pictures of the proper method?  Also, I've been taught (not by a professional) to cut a deeper notch with a sharper angle than the ones in Gary's pictures.  Is a deeper notch usually used when you're not doing a boring cut, or have I been doing it the wrong way all these years?  I see the obvious benefit of Gary's method (ie, less likelyhood of splintering), but it also seems that it would require more experience to "steer" the tree using that method.

[Larry]

 

I think...iffen I remember correctly the lower quarter of the bar tip is called the attack portion with the upper quadrant being called the kickback portion.

In any case once you get the tip in it's a easy plunge cut and you cut to the hinge to establish the correct thickness.

I can see GOL training in your future if you want to learn how to do it correctly.  And each tree species reacts differently.  Walnut needs ears cut on the sides to avoid splitting a slab off the front.  Some like a thin hinge...some like a hinge with the center bored out.

[Dodgy Loner]

Thanks for the photo, Larry.  I guess boring seems like it would be harder than it actually is, because it's so different from how I normally use a chainsaw.  I would love to get some proper training in tree felling.  That tree in your photo looks a heckuva lot bigger than anything I've ever felled.  The biggest tree I've ever felled is probably about 18".  I've cut up trees that were more than 4' in diameter, but they were already down when I cut them.

[DanG]

DL, bore cutting isn't as hard as it sounds.  I used it for a while in bucking big logs before I ever tried it for felling.  It is particularly handy when parting a windthrown log from its rootball.  Just place the tip where you want it to go in, at about a 45 degree angle to the desired plunge.  The bottom of the saw should be looking at the log.  You can begin to rotate the saw to perpindicular as soon as you are about 2 inches in.  It will go straight into the tree rather quickly.  I like to make my bore cut about halfway between the hinge and the holding wood where the old fashioned back cut would be, then work toward the hinge.  After establishing the hinge, I cut back toward the holding wood.  The really sweet thing about it is that you can take a good look at your hinge and make corrections while the tree is still stable.  You get to look at all your cuts from both sides, and in some cases even get a "do over" if one is really wonky.

Try it next time somebody gives you a big ol' windthrown pecan tree. ;)

[WDH]

Try it next time somebody gives you a big ol' windthrown pecan tree. ;)

I immediately saw sparks from the planer and jointer just thinking about that windthrown pecan :D.  Saws pretty good, but harder that DanG to joint and plane :. 

I have learned a lot from this thread.  Very good stuff.

[Dodgy Loner]

I agree.  I'll give the plunge cut some practice on downed logs and hopefully be safer next time I head to the wood with a chainsaw.

[Gary_C]

Kevin

Ever since I learned the bore cutting method, which I was taught in the MN Logger Education program with a video from the Game of Logging, I have never even considered the "cut straight in from the back" method. I have been there too many times trying to outrace the splitting with my saw and losing most of the time to ever go back to that method. Even though most of my cutting now is with the "automatic or manual button" method, I still have to deal with the big ones by hand. And this bore cutting or Game of Logging method is the best way to fell trees I have ever known.

I do not think we disagree on the best method and I also think these posts where we "nitpick" each others methods are very useful so that others will learn better ways of felling trees. I know this bore cutting method sounds difficult to those that have not been taught the method, and there are certainly some little tips ot tricks that one should know to use it properly.

To answer some questions:

The notch did also seem shallow and not wide enough at first to me. It is supposed to be about one third of the diameter of the tree deep which should give you enough width of hinge. You are supposed to make the vertical cut first and then the horizontal cut second. that way you can look down thru the top cut and watch for the teeth of the chain to break through so as to not over cut into the notch wood. The open angle of 60 to 75 degrees is to allow control of the direction of fall till the tree is almost down and then the hinge wood is broken just before the tree hits the ground.

On cutting the bore cut, as others have described start your cut behind the hinge with the saw almost parallel to the side of the tree with only the lower quarter of the tip touching the wood. Then as you cut a grove in the tree, slowly rotate the saw toward perpendicular and push the tip into the tree a ways behind the hinge. Then after the bar is through, cut back toward the hinge to establish a uniform thickness. If the bar is not long enough to cut all the way through, make a second cut from the other side. Try to keep the opposite side cuts at the same height, but if you are off slightly, it does not matter as long as all the vertical fibers are severed.

After the hinge is carefully established, cut toward the back leaving the last holding wood. Then set your wedges and make the final cut fron the back forward and watch for the tree to begin moving. If you cut through and the tree still stands, a few taps on the wedges should start the fall.

As best I remember, that is what I was taught. So feel free to "nitpick" away or ask more questions.  ;D  

[DanG]

When doing that final back cut on the holding wood, should you cut directly into the bore cut, or slightly above or below it?  It seems that this was discussed in a previous thread, but I can't remember how it went. ???

About how much holding wood do you normally leave?

[a old timberjack]

i am not gonna " nitpick" i was taught by the nhtoa timber council " northeast logger training " and the way gary explained is the exact way they tought it and that is how i do it myself everybody does something alittle different . i feel do what works as long it is safe and you are comfortable doing it. but i will say, some are better then others. but yes , you cannot beat that " manual or automatic " button...... :D

[Kevin]

This is a combined bore/ hinge bore on a Red Oak that was being cut because it was a hazard tree.
The wood went to fire wood.

boring

When boring use full throttle and a sharp chain starting the cut with the bottom of the bar tip.

I wouldn't dispute anything said about boring a leaning tree and everything said is what should have been done to prevent this from happening.
What happened to Warren's tree is what I'm focused on, this can also happen to a tree that has much of the canopy weight on the side of the intended lay.
You need to know what's going to happen before you start cutting.

Dang, the hinge wood will depend on the size of the tree and what you expect it to do for you.
Many guys will cut some of the hinge out to reduce fiber pull .

[Gary_C]

About how much holding wood do you normally leave?

I can't recall any rules stated for how much. Depending on the tree diameter and of course the soundness of the wood, I usually stop widening the bore cut when I have enough room to place the wedges. Just be careful to not leave only some of the butt flare wood. I have had trees that tear out the remaining root holding wood when I drove the wedges in, but that is OK. Just be prepared to retreat earlier.

I always try to cut the final cut straight into the bore cut,  not above or below. Many times on larger trees that are not strong leaners, they do not fall even after all the fibers are cut, and that is especially true when the opposite side cuts do not meet. However a few taps on the wedges will crack that final vertical wood to tip the tree.

[Larry]

DanG, I agree with Gary but might add couple of thoughts.  If you cut the holding wood above the bore cut there is a chance the tree can take the chainsaw for a ride.  I cut the holding wood even or a little below my bore cut.

Don't know how to answer your question about how much holding wood is enough.  It takes very little wood to hold a tree...but if the holding wood is not enough a big tree can lean just enough to pinch the bar if you don't have a wedge in on the heavy side.  For that reason, I sometimes leave a little extra holding wood.

[Gary_C]

One of my concerns with this method was the shallow notch. When you have a shallow notch, you have more of the weight of the tree behind the notch to "lift" off the stump rather than "falling" into the notch opening. With a tree that has a lean or more weight in the direction of the fall, it is not really a problem. However with a balanced tree, some wind against the fall direction, or back lean, it puts a lot more stress on your hinge and your wedges.

In the training, they do emphasize the importance of a properly formed hinge and to not overcut into the hinge wood. Also you have to be very aware of the dangers if you see or feel any hollow centers or rot in the tree. Plus a too thick hinge or improperly formed back side of the hinge can hold the tree from falling.

For all these reasons, I am very reluctant to cut the center of the hinge out to reduce the chances of any fiber pull. I think the potential hazards of weakining the hinge far outweight the benefits of absolutely no fiber pull. From what I see, the hinge breaking is due to bending rather than pulling.

[beenthere]

Good discussion, I think.
There are guidelines (Based on tree diameter at stump) for the depth of notch and the hinge thickness, taught by the GOL. At the moment, don't have them, but they have been posted on the forum. Will look. 

[OneWithWood]

In another thread a few years ago I discussed what happened when I cut a heavy leaning maple of about 22"dbh.  I thought I did everything as I was taught in the GOL curriculum.  I made my notch so the tree would fall in the direction of the lean.  When I did the bore cut I came too close to the hinge and made it a tad too narrow.  The tree promptly compressed the hinge and pinched my saw.  I had to finish the cut with a second saw by boring in just above the pinched bar (I removed the motor).  I then proceeded to cut to the back from within.  The cut would have ended by exiting a flare root.  I say would have because before the saw made it through the tree the root pulled out fibers were pulled and the saw and imbedded bar went sailing past my head.  When I stopped shaking enough to collect the pieces I took a good look at the stump.  I believe that had I made the back cut from the outside in after my second bore cut the tree would not have barberchaired sending equipment flying.  It also would have helped if I had inserted small wedges to support the compressed hinge.
I guess what I am trying to say is that cutting inside out after the bore cut works on well balanced trees but may not be the best thing to do with a leaner.  I don't fell enough trees to be proficient but I do learn from each and every one.
My next adventures will be falling trees that were used as turning trees during the last harvest a couple of years ago.  I expect that I will make heavy use of wedges, especially where the direction of fall dictates the hinge will have an end in the damaged wood where the tree was rubbed.  I look forward to discuusing the proper technique for falling big damaged trees with those of you who will be at the piggy roast  

[Ianab]

I have made the 'hinge to narrow' mistake too  :
Same thing.. the whole weight of the tree settles on your bar, and it's NOT coming out.
We took the power head off and used another saw to cut the holding wood, from the back(outside) a bit below the bore cut. The tree fell normally and the bar was just left sitting on the stump.

With leaning trees I allways cut the holding strap a few inches below the bore cut. The tension is going to tear out the last bit of the backstrap no matter how fast you cut it. Just seems more controlled when there is a bit more long grain area to snap off between the cuts rather than lots of random fibre pull when the 2 cuts are the same height. Cutting below makes it unlikely the log will try and grab your saw as it goes over. You can saw around the outside of the holding stap to reduce the chances that it will pull a section of root out with it. Leave the centre of the strap to last.

One thing you will notice different with this method on leaners, when you cut the back strap it will break with a loud crack and the tree will fall fast. You wont see the top slowly moving or the kerf starting to open. Thats your signal to start moving fast as well  :D

Depth of the scarf?
With a heavy leaner I usually just cut deep enough to form a decent hinge. It's usually quite a bit shallower than a conventional scarf but seems to work fine.

Cheers

Ian

[Warren]

Quick update.  I used the wedges on a couple trees per Gary's pix and everything seemed to work pretty well.  Actually managed to (intentionally) pitch one tree about 45 degrees from the apparent direction of lean. 

Kevin, your comment about looking at the canopy clicked for me.  The tree I barber chaired had the majority of the canopy on the lean side due to an opening in the surrounding  canopy.  I noticed that fact beforehand, but never stopped to think about the impact it would have on felling the tree.

I checked into GOL training last year, but could not find anything in the KY/OH/IN area.  If any members are aware of upcoming training in this area, please let me know.

Warren

[sawguy21]

For all these reasons, I am very reluctant to cut the center of the hinge out to reduce the chances of any fiber pull. I think the potential hazards of weakining the hinge far outweight the benefits of absolutely no fiber pull. From what I see, the hinge breaking is due to bending rather than pulling.

I have seen fallers cut a 'window' in the hinge when the bar is not long enough to have the bore cuts meet. Would notching the sides of the tree be a safer method?

[OneWithWood]

Warren, keep an eye on this site

http://www.ihla.org/

The next Cutter training in Indiana will be posted on the site as IHLA sponsors the training.  It is usually held in Morgan-Monroe State Forest which is about 15 miles northeast of Bloomington, IN.  If you should attend a course let me know.  I am just a few miles from Morgan-Monroe.

[beenthere]

I ran across my GOL (Game of Logging) crib sheet, that has the hinge length and width recommendations:

Length:  minimum of 80% of dbh (says dbh but suspect it is diameter of tree at cut).
Width: maximum of 10% of dbh.

So 20 inch diam, cut the notch to at least 16"
                          and the width of the hinge would be no more than 2" (and parallel the full length)

The hinge is one of the "Felling Five", they being:
1. Hazards (observe what they are and plan how to avoid).
2. Lean or crown weight distribution - calculate forward, back, left, or right lean and weight.
3. Escape route - plan it ahead of cutting, and clear it out.
4. Hinge. Calculate and plan it
5. Cutting plan - visualize the notch, and subsequent cuts, be they plunge or back cut, and wedge placement.

[rebocardo]

On leaners or other trees where the placement of everything is critical, I mark the notch, hinge, and backcut with crayon or orange spray paint.  That way I don't go further then I really wanted to and it helps keep the saw level when cutting on unlevel ground.

> and someone pulling too soon, or too late, just seems to lead to additional problems

Yep, this is what happens when someone pulls too late:



Note to helper: When I said as soon as the tree starts to fall, pull, I meant start pulling as soon as the tree started to tip so it wouldn't fall on the deadman anchor (my van). Not after it was already on the ground.

I guess my little lesson on the law of gravity and how the top will hit the ground in less then 2-3 seconds and you can't outrun a falling tree, 1/2 the way over, pulling with a backhoe, might need to be repeated.

[Tom]

Does it leak now?

[Furby]

 :D :D :D @ Tom!

[sawguy21]

 :D :D :D :D

[Dan_Shade]

I'm sure that's funnier to those of us who don't own the van!

I had a dead tree do that to my old GMC once during a storm!  i used a 2x4 and a hydraulic jack to press the dents out, replaced the windshield with a spare and drove it another year!

[theorm]

Does it leak now?

Tom,

There is no logic in the way the helper doesn't pull on time, it just doesn't hold water.........

:D :D :D :D :D Theo

[Kevin]

Gary, some of the hinge fibers will only bend and stay intact on an open face notch.
With the other notches the the fibers get pulled when the notch closes at the apex.

Sawguy, cutting or nipping into the side of the tree below the hinge will prevent barber chairing due to root pull.
The only reasons for boring a hinge should be to reduce the holding wood or prevent fiber pull from inside the tree which might devalue a good veneer or saw log.
If someone is using access through the hinge routinely to cut into the wood behind it then I would say they should be considering a longer bar.

One, I'll be looking forward to your presentation at the piggy fest.  8)

Hinge thickness and notch depth are general rules, they can be altered within reason to change the way the tree will react when felled.

[Jeff]

We have a very sick oak if ya'll want to get it down. ;D

[Dale Hatfield]

Length:  minimum of 80% of dbh (says dbh but suspect it is diameter of tree at cut).
Width: maximum of 10% of dbh.

NO DBH is correct.Your Crib sheet is correct.
Length is 80%of DBH. 10%Hinge Thickness.
Remembers these are guidlines a place to start.
In some trees thats going too much thickness. Depends on species. 10% would be the max ,with most hardwood trees taking less hing thickness than 10%. Hickory being a prime example
The hinge length is what helps overcome side weight and lean. Short on length and the tree will fall  but towards the heavy side .

After you have cut the tree down . Have a look at the stump/Hinge the fibers at the back of the hinge break and the ones at the front bend. No that doesnt mean that you can use 1/4 inch hinge. Because it wont support the tree( pinched saw) But as the tree starts to go in your chosen direction  the back fibers break till it gets to the front and these bend.
Dale

[beenthere]

Thanks for clearing that up Dale. (dbh being diameter breast height).  I hadn't noticed it until I was copying into the message.

And I agree, they are guidelines, as each tree needs to have it's own plan....

[rebocardo]

> Does it leak now?

Only when it rains  ;)

[Kevin]

This is a picture showing the wood fibers pulled from the tree and stump.