Tilted triangle hinge

[Oxman]

Got distracted away from the boards by a little shindig we threw around here a week or two back. Glad to report a good time was had by all. It was nice meeting some of you for the first time. And, of course, seeing all of the good ol boys again. Hope y'all got the same impression about coming to Seattle.

Noticed it took 5 pages to git around to leaving the hinge wide on the opposite side of the headlean. Now, can we move on to the part about leaving it thicker on that side, as well? This involves making the backcut by tilting the bar higher on the side opposite this headlean. We're not beyond mixing in a little 'art' with our science, are we?

The higher the backcut, the stronger the hinge. I haven't found any advantage to making the backcut below the floor of the notch. Things can get a little loose when (late in the takedown) I get too weak or sloppy to hoist the saw up to the correct location for the backcut.

When pushing over near-vertical chunks, making the backcut level in the same plane as the floor of the facecut allows it to be pushed over with the least amount of force.

 

[TheTreeSpyder]

Well, i thought that, leaving more fibre in the opposing corner of the hinge was what the whole thing was about!

i have always been werking on hitting the apex of a wide face hinge, so haven't tried what you pro-pose to much at all. When i have cut funny and come high; it does seem to hold longer; but the name i have put on it is that the hinge is hesitationg longer as it is not as mechanically perfect. i figure the holding wood technique in Dent's analasys, puts severe torquing on those corner fibers, the way i picture it Ox-man is those fibres base is under cut more the higher abaove the knotch ya go. So i am having trouble getting the picture and mechanics of what you are saying would werk.

i think coming below the backcut gives a similar situation only magnified.

On bombing vertical chunx, i do the same thing, but give humboldt hinge, the farther the hinge comes under the chunk, the more the center of balance is undermined to tilt and slide close to tree or push out the chunk from the tree; depeding on the situation. Also, i finish with a downward cut from the back for a safety stop, but mostly so the saw finishe freeing the piece; in a position where the weight isn't on the bar.

 

[murphy4trees]

Ox,
How high above the floor do you go?
What kind of notch.. open face?
Do you widen up the corner where two notching cuts meet to flatten out the holding wood to allow for the changing hieght of backcut.
It sounds like a good idea. How does one finetune for max control. I would guess at some point in hieght differential the hinge would begin to lose control.
I Am all ears.
Thanks and God Bless,
Daniel

 

[Oxman]

"Sometimes a Great Notion" was the classic 1971 logger movie with Paul Newman and Henry Fonda. Our commercial arborist crew all went down to see it at the Cinerama Dome in Hollywood when it first came out. The story was written by storyteller Ken Kesey, who also wrote "One Flew Over the Cukoos' Nest", with Jack Nicholson. Kesey was the leader of the Merry Pranksters, a hippie group doing yoga alongside their psychedelic bus in the rock documentary, "Woodstock". His biography, by Tom Wolfe, "The Electric Koolaid Acid Test", chronicled the Haight-Ashbury days of 1967's 'Summer of Love'.

I identified with the character played by Michael Sarrazin, the younger brother of the family who wants to follow along in the logging dynasty caulk bootprints of the Stamper family. Old man Henry Fonda's favorite saying is "Never give an inch", an example of the gritty determination needed by the family to get thru the tough times of daily forest life, plus all those hassles injected by the need for conflict in a major studio/literary production.

The movie version wimped out on the origin of the incestuous conflict among the principals in the story. It also changed the type of logging accident central to the story from a skidding operation to a more visual felling incident, where the tree barberchaired, causing all kinds of mayhem, and tearing off ol Henry's arm.

15 years after that movie came out, I bought the biggest chainsaw I could find and packed up off to Oregon, to be a logger. I subscribed to "Timber Faller" and "Loggers World" (as well as the J of A) magazines to get the kind of versatile background needed to thrive in the big woods.

After arriving, I found there was a demand for piecing down logs off of trees near the rural dwellings on the forest interface. These logs must be in merchantable lengths(16', 20', 24', 32'), off the top of the most valuable butt log, which needs to be 32' tall. Getting them down off the top of this stick intact (amongst outbuildings and fences) without splintering them to smithereens became the order of the day.

So, here we are, talking about how to get a tree to go where it doesn't want to go. Fiddling with the face and all. Too much ambitiousness in this type of endeavor can lead to tragic accidents. That's why we have textbooks and standards and old timers to teach the young'ns. And stories of mayhem, too.

Thanks to those who made comments here about 'hangin in there', steering the work, while it's falling, right into the intended lay. As long as that chainsaw is in your hands, and the tree is not completely on the ground, you're still in the drivers' seat.

The height of the backcut above the floor of the face was the subject that was on the table, before this long ol harangue started. If it is higher on one side of the cut then the other, more holding power will result from the taller hinge.

This taller hinge is also thicker, leaving more wood extending out in front a bit more. The angle of the second face cut leaves more wood out in front of the upper portion of the face, the higher the backcut comes in.

This is right about where a coupla good diagrams would be handy. We're not inventing anything here, so it's merely a question of digging these drawings up (hint, hint). Luckily, we're climbers, so we can take it out in the field and try it out by starting to cut leaning limbs as if they're leaning trees. Get them to go in places other than where they'd like to.

Make the face of your choice (Humboldt or conventional) right where you want to lay the work. Place the angle of the backcut on the leaning (weak) side up to the hinge at the floor of the face. You won't need much holding power here. Angle this cut upwards to come in almost at the top of the face on the opposite side (away from the lean), where you do need all the strength.

But don't cut right up to the face. Leave a bunch of wood, and wait. Just be patient. If you have a tree with enough diameter to put wedges behind your bar (on the side opposite the lean), do so. The lean will take the tree over very slowly at first, then it will take off, after it has had a chance to get started over the center of gravity.

Vary the location, depth and tilt of the backcut to modify the strength of the hinge between trees with differing species, wood soundness, diameter, and headlean. Play with an assortment of these possibilities in non-critical areas, because someday, that stick may decide to barberchair on you, Henry.

Here's a pic of KC out of Poulsbo, WA, from the Madsens Power Equipment site.

 

[Kneejerk Bombas]

Oxman:

"The higher the backcut, the stronger the hinge. "


Why?

 

[murphy4trees]

It makes sense in that tilting hieght of hinge is spreading out the area of tearing fibers... And go too high and tree will barber chair. So how high is too high?.... I know.. it all depends... but Ox give us something to work with.. 1" for every 2' of diameter on wood that hinges well would be my first guess. IS that about where to start?
I've used a similar technique on small branches to get 'em to drop slowly.. That is cutting across the branch slowly on a 45* diagonal, rather than a 90* crosscut. This spreads out the area of ttearing fibers and can help to slow down the limb's fall.
God Bless,
Daniel

 

[TheTreeSpyder]

Mr. Man-Ox;

i'm standing back hear, trying to absorb this; but keep coming up with things contrary to what you pro-pose. i've read and seen you're stuff b4; so no the scale of dropping uninjured 32' sections is out of my present realm; so am trying to stretch and see things you're way.

But, in this scenario eye see:

The pull having to pull up the incline of the slant.

If something went wrong, a wedge would have to push up too in a time of hazard and correction.

i feel that if the holding wood was scheduled behind the face cuts is more positive, for if it is scheduled over the upper face cut; then the holding wood would be more prone to snapping off as it terminated at the facecut, not going deep into the stump. This is epecially important when using cuts that place a lot of stress on the holding wood.

Something about not violating the fibres in a straight line seems out of line as i practice it, also have read warnings of such things.

i have played with not hitting the vortex of the face cut on the backcut, i don't think it is as mechanically clean; it seems to me that the extra holding power is the machine stalling, then it goes all at once. You could use that instance to your advantage with a high level of experience/ feel; but in gneral prefer smooth machinery.

When i was talking about tossing chunx earlier, it wasn't on your scale, but rather 3-8' pieces. i too stand at a tree and steer it down cutting very few fibres as it starts to go, to leave more hinge. But in all fairness must say that, that is in the danger zone, and should only be done with extreme caution.

Wellllllllllllllllllllllll; i guess that is enough 'dinging' your contribution as the devil's advocate questioning from all sides; what'cha got there on the next layer for us?

 

[rbtree]

I'm really not sure if I agree with Ox or not. In analyzing stumps after cutting, it is tough to tell if his theory is valid.

I think that a backcut considerably above the face will be less smooth in its action. As it has both vertical and horizontal displacement, it will be stronger at first, and thus harder to start moving. But then, as more horizontal hinge has to be cut, the wood fibers are more likely to break all at once.

I've discussed this before with Mike, as well as the Arbormaster folks, who seem to think that the only reason for raising the backcut is to limit stump shot. To me, it seems that a slightly raised backcut would give smooth hinging action as the fibers move and bend.They of course teach the 70 degrees or more open face, which pretty much negates stump shot, at least on level ground.

murph, 1 inch up on a 2 foot cut is miniscule, two to four would create the kind of action Mike is referring to, I think.

 

[John Paul Sanborn]

IOf you have twisting fibers and cut high, you may actualy cut out your hinge wood by cutting high.

 

[murphy4trees]

JPS,
I heard the same theory about twisted grain.. That was referring to the 2" higher back cut as per Dent's recommendation. So I would think that for 2" height differential to make much difference, the wood would have to have some very twisted grain. And that may be very significant in the "take no chances" school of tree felling.
And I have been staying with level back cuts for as long as I can remember. Preventing kickback is rarely an issue for me. I haven't seen any other advantage to 2" as recommended by Dent.
In thinking about the tilted hinge, it occurred to me that the same effect is created by cutting a level hinge on side leaning wood. The hinge tilts or is diagonal relative to the plane of crosscut. I haven't paid attention to see if this improves the holding ability of the hinge. Though I have started to bring home a collection of hinge sections cut out of smaller diameter wood. I Am going to try thinking as if I was Spidy, when examining them.
And I also have a concern that the models developed from studying the small stuff will not work for bigger wood, due primarily to the different qualities in older wood fiber and the vast difference in force at work.
Will someone please tell Ox to turn his computer on. Ox are you 100% positive on this one. More info is needed.
Thanks and God Bless All,
Daniel

 

[murphy4trees]

Ox...
Where are you.
Anyone know?
Daniel

 

[Oxman]

Last time I checked, I was all there. Hope this is getting through. Let's move on to some of the later chapters. "Fundamentals" and "A Procedural Approach" touch on some moving topics. Discussions like this are grounds for digging the references out and taking another look. The implications in clear, descriptive language are many. Our mentors used simple language to impart very subtle mechanical principals. If we are sensitive enough to suspect the implications, we can move past the basics into advanced control methods. A good student needs to get dirty to uncover secrets unearthed by the masters long before. Shigo says, "Touch Trees". Do we think he's just kidding, that we can understand merely by reading his books? Nope, the things we hear only allow us to SUSPECT that there might be more to the issue. To find out the real skinny, we have to go out and AQUIRE the knowledge. It is not handed to us.

These falling principles can be massaged into radical mechanical manipulation, when used to within the limits of applicability. Thus far, we have really only discussed nudging trees slightly out of their lay. The 'art' comes when the hail mary nudge turns push into shove. Do we want to be able to pull things off that will turn out to be real time/labor savers? Or, do we just want to reliably release trees where they can easily, predictably go?

So now the question moves to how high the backcut should be above the first facecut. Rather than inches, lets consider this distance to be a percentage range. Can we temper the cowboy with safety?

If the facecut is made in a smaller tree, I believe this distance is going to be in a smaller range, say, 1/4 to 1/3 of the height of the notch. If the tree is intended to go where it is leaning, this cut will be level. A larger tree, over 24", for example, will let you make the backcut higher, up to about 1/2 to 3/4 above the floor. This amount depends on how much force the tree has getting it started. If it is balanced upright, and needs all the help it can get, the backcut will be between 0% and 1/4 of total face height.

A bad sideleaner can allow you to put the high side close to the top of that side of the sad face. The low side (which you want to be released early) will be between 0% and 1/4 of the face floor. This is in combination with leaving the hinge wider on that side, (not cut through as far) of course.

These numbers are way higher for the Humboldt cut. It's almost like they don't apply, the two are such different animals. This situation puts the backcut at least 150% above the lower lip of the happy face. Otherwise the hinge can break right off the bat. Which can cause the tree to head off sidewise in the direction of headlean.

Now for another subject. I keep waiting for folks to bring up the snipe at the front of the face. This is an angle created by slicing off an angled wedge of wood off the front 1/3 or so of the floor of a conventional facecut. It can spin the tree by allowing one side of the face to close before the other. Rather than allowing the tree to fall in an uninterrupted arc, the direction is changed in mid-fall. This happens by levering the tree over. The purpose can be to roll the tree, stripping all the limbs off, so it doesn't have to be limbed by hand.

Moving along, another way this mid-course correction can be instituted is by sticking a small chunk of wood into the closing face, on one side or the other. When the face closes up (at about the 20-45 degree angle) the top encounters the chunk, pushing the tree to the opposite side. I call this technique 'tipping' the tree. I'd be interested in some other regional names.

As the tree falls, its direction becomes more obvious to the faller, who is standing right behind it. Fallers get this speeded up metabolic rate, and seem to think they can jump in quick like a mongoose and deflect the cobra strike by dropping in this corner of a wedge, either to the left or right, or the front or back of the closing face, depending on just where their new-found idea of the trees' destination will be. Some use their heads, and place the chunk before starting the backcut.

In the same breath (sorry to complicate the thread), the swing dutchman needs to be brought into the discussion of controls implemented after the tree starts to fall.

Simply put, one side of the floor of the face is extended back from a few kerf widths to 10%-20% behind cut 2 of the face. The tree will pull to this side very shortly after committing to the fall. The earlyness and degree of pull never fails to astound me. It's almost like Gepetto is up in the clouds, yanking this tree around like Pinocchio on a string. Talk about defying the laws of gravity!

Do we really need the standard disclaimer here (Don't try this at home)?

Yup, this stuff is for experienced tree workers only.
Here's the article where the illustration came from. We still need some drawings, though.

Washington State Logging Standards

 

[TheTreeSpyder]

WOW!

Very gooooooooooood! Nice info! Gasm Time Rob?




This is where i thought you might be headed, but didn't want to bring up, this in tandem with the more holding back then sudden throw of slanted triangle putting momentum in here as you use slamming force of faces meeting to push head weight to opposite side. This increased, higher shock force with one side closing earlier than the other (in tilted triangle, dutchman, block of wood, shaving one corner of face etc.) does the work.

i guess i have gone the other direction in my explorations, trying to get less violent, softer energies; whereby you are werking on the end of allowing all that slamming force to werk for you. i have dutchmanned a few times, cut the lip on the conventional hinge on one side, kerfed one side (so it has seperate hinge that closes earlier) etc.

But have gone with the unpictured open face cut or wide mouth, serving backcut into its apex; that instead of tearing off early on one or both sides, tries to hold on as long as possible evenly. i think it is mechanically smoother, won't say better; cuz i well imagine there are uses for both; and you are really useing power, that i try to minimize!

Any of this should carry more than the normal warnings, especially Oxman's last post, very sudden and violent powers captured and orchestrated here! Stuff, i'll admit i've shyed from!

P.S. in all humility, i might add, that IMAO this is a step beyond what i pro-pose, infact builds on those s-kills but then, that might mean step thru my way first!!

 

[John Paul Sanborn]

I would say, don't do this unless you fell regularly.

I gotta stick with ropes, wedges, and The Winch for the realy big trees (Big trees here that is, not your neck of the woods with 90 foot crabapples)

 

[TheTreeSpyder]

Here is pic 1 in setup of hinge (as i see it).

Most of my stuff goes to minimizing and ushering force, this goes the other direction, it maximizes force, and uses all that moving energy to slap an uneven face, while causing an earlier tear off on the lean side of headweight, that is also , high side of hinge. i have been luckier in my venture(as opposed to these strategies that Oxman pro-poses),as i am trying to usher smooth, slow movement- it is a lot easier to catch what is going on as you 'practice'; more subtleties exposed. This, direction to the same end, everything is going faster, harder to catchit all in your exam-i-nations; more deadly if ya got the 3rd try wrong!

This is an even more potentially dangerous controlled motion than usually, that should be built up to, not jumped into!!! We have talked of not posting this somewhat, as it is that dangerous if it can get away from you! Wouldn't want anyone to get injured that stands under 5'5", just isn't enough of them cool guys!

But, the general consensus is, if wee shouldn't post it on this top, high volume, pro site; then there would be no where else to! A pro that does this all the time can (hopefully) tame this monster, a seasoned, highly trained pro that doesn't use this every day; should stand back!!!! - IMAO; at least till s/he develops a sense of these things; building up to them.

This is really more proffessional logging than municipal trimming i think; where there might be more room for error in open territory!

P.S. maybe i should post some warnings with this....

 

[TheTreeSpyder]

"These falling principles can be massaged into radical mechanical manipulation"
"Too much ambitiousness in this type of endeavor can lead to tragic accidents." -Oxman

IMAO, really this is Ox's territory; but me-chanically if i had super side lean to usher to face with this tecqnique, i would want a heavy leaner to the face too. Putting as much thrusting forward force, instead of strategy of limiting it, as this is the how this intense machine builds power to werk its magic, by maximizing force and impact, to use that force to pull that impossible weight forward into the face.

Just as in other hinges, you face the tree to the direction of lay. Adjust hinge (triangle) for adjusting pulls across the hinge, then stir in high step on leanning side of face perhaps to close earlier (more power with more slaming force) ->pushing lean to opposite side that is flowing freely, making hinge tear off earlier on lean side->to pull to opposite side, and/or slanted backcut->forces stall as force builds pulling lean side around more violently.

By scheduling and controlling these forces at peak, massive movement, more pulling power on an off balance head can usher that off balance leaning head into the projected lay than triangle hinge alone.

It is trickier and more dangerous, even Ox that actually uses this speaks of having a nervous system of an adrenalized mongoose and cobra battle, though i don't think jump in... means going in front of anything.

Well, i bow out here, here's my virgin of the pix, this is one
wild bronco to ride confident-ally, might not have it all 187%write this time; though that seems consistent to what others see anyways!! Part of my experience conflicts with his on deeper kerf, but have steered more away from these things, perhaps eye didn't watch long enough, soooooo.........

 

[FSburt]

Interesting thread on this subject. I have used swing dutchmens to keep trees out of drainages so we did not have to hand pull the slash out of it and it works alot of the time but there are a few times I have had the tree settle sideways and back very hard and the only recourse was to cut some wood from the face cut on the offside to see if I could redistribute the weight to the side and back towards the front this is very sketchy cutting and you have to be very quick at pulling your saw out to keep it from getting pinched up in the face. It has worked about 90% of the time and the other 10% the tree settled back even harder and broke off sideways. We are not talking about huge trees small ones 10 to 16" dbh. It also depends on the tree species yoe are working with I have done this only in Pine and Fir and Oak but never in Cedar or other brittle wood species. I don't think I could bring myself to use a dutchman to swing a large piece of wood out of a tree near any houses that to me would seem a bit too risky. I was always taught that sloping backcuts undermined your ability to wedge a tree efficiently by pushing a tree forward instead to lifing it towrds the facecut. That is if the backcut slopes down towrds the holing wood.

 

[TheTreeSpyder]

From another thread i wrote: {http://www.arboristsite.com//showthread.php?s=&postid=39880#post39880}

"Then we went to dutchmans in that same thread Ox started, where he uses rushing force of tree to steer through forcing the faces of the hinge come together more violently, then using that maximized force to steer the tree by one lower face side of the hinge being higher than the other. Actually, that is more powerful (and riskier, he must be really doing this a lot to confidentally control it)) than the triangle we talked about, but i belive he combines the 2 to compound them! The tilt in the triangle he pro-poses, i think makes load stall, force build, then rush at once, usherring that impact into maximizing the force of the 2 facecuts slamming together throwing it from the high step to the low one, the thin end of the triangle hinge releasing earlier than the thick one and allowing this."

Thought this pic might help.

i am very surprised more people don't see how important it is to realize all that is going on in these cuts.

Even if you never lay them out, it is very important to know how they werk, in case someone mistakenly sets something up that fits this scenario, what forces that could call up. Doing simpler hinging is fine, can even get where ya don't do everything perfect each time, but knowing at what point being lil sloppy in your cut, or another's and not being able to recognize what you have invoked can be disastourous. In fact, if nothing else, these exam-eye-nations, should further instill how much care is in imperative in each hinge. That, this decay in this key spot of the hinge with this weight is real bad or not, that that face lower on 1 side might throw it all off-or no-maybe this time it will help, that the hinge violated on this side is dangerous-well maybe this time it is not etc.

 

[rbtree]

Spyder,

As you may know, in most commercial logging operations, dutchmans are considered illegal to use.

I've had a discussion with a local arborist, re tilted hinges. He used to be a fire crew hotshot, and has tons of felling experience, which I sure don't. He strongly disagrees with Oxman's theory, which I think I do too.

As well, the stepped backcut is primarily to limit stump shot. With an open face or Humboldt, it is really not necessary, nor does it improve hinging action.

 

[TheTreeSpyder]

Welllllllllllllllllllllllllllllllllllllllllllllllll,

actually i asked a few people (thought u was 1) before going on on this subject, for i consider it dangerous, explosive physics. But it is real, and therefore, if not discussed on the best most active board of pro's, then where??

i understand these things, yet don't use'em (though have been kinda starting to drool about experimenting with it more on my journey, as i've written these things). Never been a logger, but understand a smatterring of that world. So, i look at this as the extreme of all these powers available and seek to learn lessons at that screaching high end of the art, to reflect back in other things far simpler, to have that richer background to call from in decision making, to be able to further understand the important powers. To make sure these things aren't invoked accidentally and the like; or be able to diagnose unpredicted movement on a drop, to learn more for the next time.

The tilted hinge could be real tricky, but getting it to stall up a hill and throw suddenly, when you are trying to maximize force into the slapping faces of the face cut on a step, dutchman or other uneven face; would be to maximize the adjustment of the stepped face. But it is more dangerous too for that suddenness, and not much ability to alter to much with back wedge that wouldn't lift higher than the step in an emergency.

Agree totally on the stump shot and step on conventional hinge as safety for 'anti-kickback'. In fact agree that especially as municipal arborists these things we speak of here shouldn't be used; but feel they should be understood. And sometimes for a real depth of understanding i study the high end of everything tuned to see what that takes, and the low end of a subject to see what is minimall, and what barriers that presents.