I was wondering, are there certain circumstances (when felling a tree) that require an "open face" notch instead of a "conventional " notch? Or are they just different techniques? Thanks for your input,Yukon.
With an open face notch, the hinge wood will hold longer giving more control in direction of the fall. But with a narrower notch, you can get the tree to 'jump' further off the stump because it will break when the momentum has the tree moving in the direction of the fall.
I've had too wide of a notch on huge floppers and had to cut the log off the stump in order to make a stump cut. But it's useful if you have a narrow landing zone. Be sure to make your back cut an inch or two higher than your notch to help prevent the tree kicking back on you.
An excellent book describing notches and many other aspects of falling is "PROFESSIONAL TIMBER FALLING-A Procedural Approach" by D. Douglas Dent.
Its got lots of good illustrations and descriptions of notches, backcuts, etc.
There is s current school of though that says the back cut should be on the same plane as the apex of the face cut. This is because with twisting grains you canneffectivly cut your holding wood out in a portion of the hinge because of the rotation of this twist. This is more likely to happen then the butt jumping back.
With degree of face, one can determine where the hinge will break by how open the face cut is. (well, I can, in theory only. Felling is not one of my stropngest skills. I'm getting better.)
i think a hinge is a machine, to usher all that weight x all that length (lever, with weight on end; pulling at hinge) x any accelerated speed into a target adjusting for head balance etc. A finely tuned machine can be a beautiful thing to gracefully usher such power. i think unless you want something to specifically fly away from you (like in tree) or bust through limbs etc. (using available force to your benefit), you should work on walking a hinge to a point of failure, and not cutting through it. i look at precut condition as 'hold', cut 'fall'; hinged as 'fhold'; somewhere in between.
As long as the tree holds on; you have some control over speed (impact) and direction. When the faces of the 2 cuts meet; the machine of the hinge must shear or sieze, so a wider face cut can delay this, and give the machine command to hold on longer. Thus, you can more precisely control the direction, and make land softer with way less damage/ more forgiveness.
The facecuts must not cross each other, for this (as Dent puts it); makes a face within a face; and the machine of the hinge is less predictable, and essentially micro face cut sometimes. Like in a kerf cut; imagine the faces slamming shut immediately and all that force and leverage building up, wanting to explode in release; that is opposite of wide face. The hinge is a gravity powered machine to usher all that moving mass and leverage of the tree to the ground; perfecting it will make such a positve machine; with real power, precisely tuned.
Now, if you can take all that, and pull (or lift, or both)the tree (or limb) manually into hinge sooner than it would naturally(with more fiber holding), it can have more control through the sweep, and then manipulate the holding fibers from side to side to adjust for head balance, and brushing other trees on the way down, ushering into the exact horizontal focus of both corners of the hinge/ facecut.
Some guys, horizontally center punch the hinge, to eliminate the least elastic part of the hinge. This gives a nice sight hole, leaves more flexible fiber as control, and eliminates much splintering up the log (at highest yeilding end!)in the logging industry. Though it drops the amount of usable fiber so is best only in healthy wood. It also, lessens the pull of holding wood at the corners i think, as the cornes of the hinge don't have that center 'post' to leverage the pull of the holding wood through to cross-effect the other side. For as in many things here, the left pull of hinge; limits the right leans pull. So if it is leaning right and will fold forward at 500 fibers, then scheduling 350 of those fibers to the extreme left corner of the hinge, can act as/ or compliment a high leverage forward/left pulling line to bring off balance tree evenly forward.
i agree with JP on coming right into the apex, but there is a warning with doing that with a conventional hinge. In that hinge, if you cut through the hinge too early, it splinters, or siezes etc. and it is cut through flatly at the apex, that bottom flat face can deliver the top slanted face into your lap with all relevant force. The reason for coming up 2" from apex in this cut is so the resulting 2 " step would be a positive catch/ lock to maybe save a life or limb. The other 2 cuts are machined with the bottom face slanted down, that would usher such an incident forward and not back; so attacking fibers as he suggests is safer i think with them, though i do as he does on conventional when i use it. i just make sure there is no other compromising factors/ hinges/hangups etc.. i always say"You don't want to make 2 miss-takes at once!". So if you can recognize/ weigh them out, define them, you can make informed decisions as to 'forgiveness' levels.
i love Dent's book; have practiced all this on the ground, and now use it in the air, to hand off limbs into the rigging gently with the hinging technique he presents for stump cutting. The holding wood is always scheduled on the top, wide nothches, not crossing, whose focal point is angle i wish to move limb. We pivot many things off roofs, through wide sweeps, with hinge as an extra/detatchable support line working in tandem with the rigging line. There is less rope stretch like this because there is less force, pulling down because of hinge carrying some weight, speed/ impact lessenned and any of the total force moving sideways is not pulling down on rope. Also this technique can be used to prestretch the rope gradually before tear-off of hinge. After the hinge and length between it and the rigging line usher the head off the roof, (sometimes 180degrees), the hinge is cut and the heavier head goes down into the yard and lifts the butt up. If the riging anchor, and loads hitch point are plumbed in line at this point (detatchement), it won't jostle and jump around. The the butt end becomes a buffering ballast to head falling. Now if ya reach around under load and hitch to pull side, you might be able to get that rigging line pulling tight to torque that head around compounding all that action, getting confident even closer to the roof.....................
After all they are both just manipulating fiber and face( i think of the face also as a tire chock that is removed, so force may flow); to buffer and direct force - the more you learn on one, the more you can cross over to the other. Exactly the same but diffrent!
Thanks for the feedback. Kevin the OSHA web site was real helpful. Hey Tree Spyder, I' m sorry , but you lost me. I'm sure it's a great technical explanation, but It's way over my head. Kinda new at this stuff !!!! Thanks anyhow.
that's a great site!!!! lot's of good info there!!!! i'm taking down my 1st pine tommorrow and came to the site for some advice, but, as usual, i didn't even have to ask the question! it was already answered!!!! i'm stoked about taking down this 60 footer! it's already dead and is sitting in the middle of a 5 acre lot w/ zero obstructions. a great tree for me to apply some of my new found knowledge!!!! great site thou!!! wish me luck!!!!
As tree climbers we are in a unique position, in that we make so many notches as we work, topping out trees.
I make 99% of my nothches with the backcut on the same plane as the notch. If you watch the little pictures in the OSHA vidios, you will notice the little shelf created by cutting high does <I>nothing</I> to stop the butt from comming back at you.
The worst thing that happens when you cut high, is that you may cut past your notch and loose all the holding power, without knowing it. With the backcut at the same height as the notch, you can see when you are starting to cut through the notch.
These comment may not apply so much on the ground, as in the tree, when you are less able to move around and inspect your cutting, from all sides.
The open face notch is described as the safest, but this not always true when you are climbing. You may need the piece to break off cleanly at a certain angle, to make a proper landing.
Imagine taking the top out of a stripped out spar, I think you would want the top to break off early(shallow notch), not staying attached until it has huge amounts of momentum(open face) and flicking you on the remaining spar, like a booger on the end of your index finger.
Be sure to walk around the tree and look for any lean from all directions.
The upper weight of the tree can also cause an unbalance making the tree twist and fall the wrong way.
Wedges are very helpful felling tools and it doesn`t hurt to keep a couple handy.
Sorry about too 'technical', and long. Trying to help and give guiding imagery, that i visualize everyday checking my cuts! A lot i have gotten from pouring over Dent's book many times, tried to bring you into that. Perhaps i threw at you years of personal study to absorb all at once..........
i have seen a few videos that show how that shelf is supposed to stop the spar from coming back in conventional hinge. That is where i learned it, and it seems logical. One that comes to mind is a Stihl video i have imprinted in mind from watching so much. So the decisions i make for myself, might not always match what i would guardedly recomend.
The hinge is a machine. There is caution in dead wood that that machine piece is compromised; and could fail. First 20 removals should be live i think. And very high respect maintained for awesome power and size of forces you are dealing with.
In tree, i use conventional hinge, i feel it throws away better than others. i think the others deliver closer to tree and tear off later. i try to make hinge neatly, and eliminate wood from the sides too. So i can fly through with saw that is cutting less fiber. With less fiber (because sides are cut), saw will cut faster, then i can slow down if i want, or speed up cut for precise control. i try to get it to detatch about 1:30, so the top is committed and the kick of energy at the but goes down into the spar and not across, nor pulls. i do all this to try to get perfect topping, that spar i am on has no noticeable movment as top flies. This is a good skill to practice and use. It may save your life!
Mike, if you leave some limbs on the spar, their motion will dampen out the movement alot. Same with piecing a limb down, if you take just enough away so you can rig then work your way in/down it takes a lot of that shaking away.
I was suprised how many people did not know this till after the Savannah conferance. I used to think of it as inertial dampening, but the engineering term is mass dampening. the mass at the end of the limb lfexes and moves, slowing the rest of the tree down.
This is a great thread that I think will be refered to quite often as the discusion of face cuts comes up again and again. Alot has been covered here already so it makes it hard to contribute.
That being said... here is my $.02 worth. First of all I have to agree with Treeman and Spyder that Dent's book should be in every arborist's library. It should be dogeared and worn with lots of pitch sticking the pages together too. Very few trees are of good sound wood with no lean and all the branch weight convenienly on the same side of the tree as the direction that you wish to fall it. All too often you want to fall it North, The branch weight is South (Phototropism), The wind is blowing West and its leaning to the East. Plus it's over half rotting which is why you are taking it down in the first place. Dent's book goes along way in describing in great detail how to cope with this. Add in a half-inch insurance line to pull it over and anchor the line to something so that the tree cannot go over backwards.
I'm not a big fan of the 2" high back cut myself although it is generally accepted as proper. I never use it when I am topping something out. If you make the mistake of cutting too far or too high on your back cut the hinge will snap behind your chain and grab the saw and try to take the saw down with the top. For this reason I refuse to have a lanyard on the saw when I am making topping cuts. I always unsnap it from my saddle just in case. I'd rather buy a new saw than have it pull me in two. I've never had to buy a new saw for this reason but I have had to yank it out of a falling top more than a few times.
Other things that I haven't seen mentioned are that you should have a cleared path of escape if you are on the ground before you start cutting. Know which way you are going to run and make sure the barbeque and the radio flyer are out of the way. Check for hangers that can be dislodged by branches from an adjacent tree or any other danger.
TreeSpyders 'technical' dialoge of putting face cuts in branches and scaffolds and swinging them over and around useing the forces of weight and gravity may have been a bit confusing but at some point you will learn to use these methods. Reread what he said over and over until you understand it and then practice it allthe time when you have the time and there is nothing to break. I wish that he would write a book about 'swing cuts' as they are very useful and there isn't too many people with that much experience or practice to pull it off. It requires a "feel' for how much bite the saw is taking, an exact angle on the hinge, how much holding wood to leave on top of the branch and what kind of wood you can do this with and get away with it. It basically comes down to practice and experience, but boy is it fun!
Another thing to practice when you can is chunking out 6 to 8 foot sections and get them to land flat in stead of 'planting' them. This will give you a feel for how open to make your face cuts. Try different face cuts and note what happens. Learn how to get them to jump off useing conventional face cuts or open up the face cut and get them to do a 11/2 gainer off the high dive. What happens if you make your face cut 2/3 of the way through instead of 1/3? How can you apply that on the ground?
With all the expertise on this forum I wonder if we can put together a chart that rates all the different species of trees and rates them by their ability to hold a hinge. I think that this would be quite useful and maybe we could even get Sherrill to put it in there catalog along with there other usefull charts like the wheight of green logs and Btu charts. What do you think?
All should understand and agree that an open face is the safest notch to use. In fact, it's use is required in many eastern states, I've heard.
That said, I believe that its use should not be mandated. For instance, when logging straight grain douglas fir, I use a deep, very shallow face to slow down spin rates, just as you described.
For example, when you are up 30-40 feet and cutting a 26-36 foot log, it will land anywhere between flat and nosing in and falling back. The desired angle of entry is 15-30 degrees from flat, which could break the log. (Flat is fine, if the log is beefy, shorter, or it is not being dropped from very high.) Sharper angles will do more landscape damage, and, if misjudged, flip over, with potentially disastrous results, depending on the target. I have used this technique for years. If I've had a screw up, it was caused by failure to put in ears, ( aka splint cuts, side cuts), or cutting near or through a knot. One of the respected Arbormaster trainers felt my method was very risky, But I begged to disagree.
I almost always use a Humboldt for conifer logging, to maximize wood production, unless there is a target, or the tree has lean or obvious defects in the cut area. Conifers are well committed to the fall, so, in most cases a 30-45% degree face is more than adequate.
Dent's book is invaluable, as well as Beranek's "Fundamentals of General Tree Work."
Plunge cutting is also highly recommended for head leaners, and also taught by Arbormaster. Very good to know and do, I like it, just haven't used it much.Here's a reasonable alternative: Set up the hinge in the shape of a triangle, with the apex directly behind the hinge. corners cut out of course. final cut is straight through, fast. Never had a barber chair with this method.
Actually, Steve, an openface notch for topping should result in the smoothest release of the top from the stem, with no push back. But I almost never do it, as I usually want the top to land flat. If I don't want it to sail out, I'll grab it as its going and give a swift tug backwards. and flip it or hold it to speed up or slow down its spin rate. Tough with a top over 10-12 inches. Keep hands clear of the fast closing wedge! Learned that many moons ago!!
In topping i prefer conventional hinge, and try to get it free at about 20degrees or so (1:30?) and get it to fly away. i find the least amount of shock like this. i get htem to land flat like that too. As it leaves later, it can kick back of spar and rock you, later than that it can pull spar forward and release with similar effect. i try to get it to sneak off me like a ninja walking by....................... Kind of like doing a real clean job, and blowing the sawdust out of the grass, like a ninja.......... i too, have thrown a saw away, rather than get pulled with it in spar, if you feel that happen, you only have so many degrees that you can safely pull it out, before having to release it and hope log doesn't flip on it. But that has been many years ago.
i don't use the step myself too much, never in the air. But present it with concerns of safety to who might be trying it, as it has been taught; and the mechanical examinations of the motions make sense. Once again, if the face is clean, the tree doesn't hang and you don't cut through the notch, you might not need it either. But- none of us is standing next to a new guy playing with these forces, so choose to err on the side of safety personally.
In Beranek's book, he has pages on getting a topped log to flip so many times before hitting ground, and land on a certain face of the log. The compariosns run in examinations to height of drop and length of top. But, it has been a lil, beyond me..........
i think rigging oak down here for hinging around is best to practice notching and to confidentally gain experience. On ground, perhaps pine. This of course assumes live, un frozen wood; whose fibre strength and elasticity is not compromised.
Realizing both are similar, and examining one to learn about the other as well as it self; should maximize your effort and learning. Examining and reading your torn hinges after each cut and witnessing the outcome will give you deeper understanding and respect also.
The hinge is a machine to usher movement. The type of face, depth, holding wood, speed of backcut etc. are all machine instructions. Whenever you hinge something witness the motion, and diagnose the machine instructions you gave it-whether it went right or not!
i look at rigging as gravity powered machines, the more i back cut, the more power i am allowing to machine. The wider the face, the more the sweep. The wider across, the more fibre to manipulate. The holding fibers at corners adjust for off balanced pulls (and pushes sometimes) during this motion. Of cours in horizontal limbs, you would schedule this holding fiber on top mostly, as pull is straight down. In rigging i try to hand the load off to rig with hinge, not slam it into rigging line. This can eliminmate all the force except the weight of the load; ie. no impacting. Speed is so important to force, that according to physics a car smashing into a wall at 35mph, has 40% more force than one at 30mph! Another interesting tidbit, is that car at 30mph hitting a wall has the same force as hitting it's exact twin in weight and speed head on!
There is a lot of feel on sweeping limbs around as i backcut adjusting speed and angle of saw while watching the head for every perceptable movement. Ushering the motions slowly helps your reactions be quick enough. Cutting down gives the machine more power, while cutting across gets it to pull around. Of course you can't do to much of either, and must constantly adjust. You must know how much that machine you made can take; and not make it shear. if you think the hinge can't handle what you will ask of it, put tightened up rig line at a leveraged postion to assist. i still practice this hinging, someitmes showing off, on free falling logs without ropes. Besides, any of the total force that is moving sideways, takes away the force total impacing directly into the ground. Same thing in buccking logs/branches on the ground. Predict where the notch should deliver log and how to get it to pull away from you. Learn here and connect it to rigging and dropping- for it is all the same, exactly the same but diffrent!
OSHA reading, not as easy to navigate as it should be.
Ended up here cuz I'm just a DIY firewood cutter working from "old" tutorials and got my neck handed to me by an instructor at Samaritan's Purse in Nashville last week while doing clean up work. Apparently, his motto; "The beatings will continue till morale improves" LOL Had to chew on my cheeks a bit but DID learn some new or better techniques, not so easy for an old dog to admit. So am doing some follow up. Any other good instructional material out there?