Dent on Hinging

[murphy4trees]

Spidy,
Oh yeah.. skinny pines.. I got the threads all mixed up... exposure to pesticides in the early 80's and Lyme disease since has effected my nervous system.
& Thanks for the good diagram.

'spin' is meant as flipping end over end?
I think tumble or tumble rotation is a more accurate term. Spin is what you do with wood on a lathe. These B boards are good for getting us to focus on the words we use in describing concepts and physics that happen in tree work. We've done this work and thought about this stuff for so long we have an almost innate sense of what is happening out there, but never had to put it into writing before. We are actually developing language. I Am working to get words as accurate, concise, and precise as possible, leaving no room for ambiguity or misunderstanding.. a real challenge.

Kev,
You must be a logger.
When you have to drop a tree between the fence and that nice azalea, you stay right behind it with saw in the back cut and steer it to the ground. It's a different game.

So the question here is when dealing with side lean do you use a rectangular hinge faced off center of the desired direction of fall to compensate for side lean or use the non-parallel ( what do the mathematicians call that?) hinge as per Spidy's diagram?
Which is stronger?
Which gives more accuracy?
Perhaps it depends on the type of wood fiber.
I've always used the former, which MM promotes, and I would like to field test the latter. Dent seems to promote the latter.
God Bless All,
Daniel

 

[Kevin]

I have to rule on the side of safety when it comes to dropping trees.
You can turn a straight tree to some degree but trying to drop a leaner in a different direction other than the way it`s leaning is a bit of a dream without some other means tied into the equation.

 

[TheTreeSpyder]

This is one of my visualizations of this as i have been able to digest it over time. i have held it back, for safety considerations.

This system could build up severe forces as the tree falls, please take the "Do Not Do" warning seriously.

Once again, the experimenting with placing face and back cut into small limbs and pulling them or pushing them over to fold, with no saw at that point gives me a very closeup, slowmotion view of all this, on a small safe scale.

 

[rbtree]

spidey,

Do you have a slow or fast net connection? Anyhow, i'm getting video editing software isnstalled soon, and should be able to resize some clips to a sendable size. Got some of dropping 34-36 foot lengths

I dont want the log to flip end for end, that means a lot of travel. You'd need a big lz for that. When dropping a 26 or so foot piece from 60 plus feet up, it is really hard to control what it is going to do.

Once, knowing that, and trying to avoid breakage, I dropped a 76 foot fir log with branches on (not enough) from 80 feet up. It landed flat, which I figgered it wood, but broke. I still got 300-500 or so board feet out of it, plus 2200' from the 2 butt logs. The tree was about 185 feet tall. We got well over $2500 for the wood, and the tree probably took three hours to do. split the proceed with the customer, which included another 2500' or so in five tall skinny hemlock.

 

[TheTreeSpyder]

Rog. Beep-Beep, RoadRunner connection here!

Well, i had to ask on the spin deal, becuase at first that is what i thought you mihght be talking about, per the Beranek refrences, for he has a math lesson on that in"Fund. of Gen. Tree Work". We don't get anything for our wood and so i have never confronted that issue! In topping i go for safe landing and low kickback; yours makes an interesting twist in the methodology and my view of how this comes out.

Inter-arresting paradox in that hinge deal i think Mike. Less fibre is weaker, but can be scheduled to pull harder than a conventional hinge strip. For their will be less fibre in triangle, because of the extra torquing of farther back hinge fibre giving more resistance to pull. So at equal tearoff force of the 2 systems, less fibre->working harder->on the same load

If 2 30' apart lines are supporting a load 60' up evenly, if you slacken oneside, the load will steer to the other line with tensed fibre, that side is working harder even if the other rope is stronger. When you put too tight of a bight on a line, the inner fibres are slackened, and only the outside fibres are tensed and carrying the load, so it is weakened.

So in the triangle hinge we position the fibres to tourque and pull more (back row tourquing and stretching over front) so they are pulling harder, then favour all that to one side.

If we put an equivalent amount of fibres in a 'rectangle hinge' as a 'triangle hinge'; which would be stronger? i guess i was waiting for someone else to ask/state that to your challenge.

If we can really understand all of the hinging, we will have one of the basic components of all that we do.

 

[TheTreeSpyder]

I'm with MM , we could jsut focus on hinging, kinda thought we was........

But then, perhaps move on to exam-i-nation, of other components of cutting, rigging; naming the powers that control them, so we can recognize and call them out from any practical application or 'word problem'.

A lot of these princi-pals would go for felling ang rigging jsut the same, with the same elements, tools and properties.

Some of these other topics would be: hitch point to the load, leading to balance of load, leading to length of lever between hitch and hinge, angle of line to overhead anchor, tightness off rigging line, gravity bending (speed line), splitting and extending anchor points etc. -IMHO.........

Then work on their combinations, to compound the maximized individual effect of each into a smooth ballet of ushering an awesome mass and leveraged limb, hinging lightly around from hazard area to clear zone with grace and power. Constructing a self working machine that is powered by you releasing weight into it to usher these things on its own self.

 

[murphy4trees]

Spidy,
You see this work with the eyes of a poet.

I had a syncronistic experience this morning relating to the subject. I think that answering this ? about hinges requires a clear understanding of tension and compression wood.
I got a call this morning to clear a large downed branch blocking a commercial parking area. It was a 12" diameter oak limb. No wind, it just dropped, sometime before 7:30 AM. I've seen maples do that in midsummer but never oak.
Forensics of the broken fibers showed a relatively small area of decay, maybe 15-20% of crossection of branch, that seemed to be well comparmentalized. I wouldn't normally expect that little bit of decay to cause the branch to fail without wind or ice. The key here is that decay was on the top half of the branch, tension wood. There was also a crack, caused by the brach failing, splitting the branch almost perfectly in half, top from bottom, lengthwise for 2-3' out from the break. And lastly the bottom half, which was 100% sound wood, was broken off about 6-12" in from break in the top half fibres, which showed the decay.
What happened here is clear for those with an understanding of tension and compression wood.
What do you think happenned and how is it relevant to the question of which hinge to use with side leaners?
God Bless All,
Daniel

 

[murphy4trees]

Ok you all had your chance.
The rest of the story follows.
I was examining the break and related crack after completing the cleanup and decided to save a 12” length of the broken limb. A man in a shirt and tie walked up and with enthusiastic curiosity asked “what happened here?”. I showed him the piece I was saving and the relatively small amount of decay, explaining that “I wouldn’t normally expect that to cause the branch to fail…but”. And before I could finish the thought, he said, “because it was on top”. He talked about studying engineering of steel I-beams and the principles of tension and compression taught there. So I began to think of a branch as a round I-beam and realized what happened.
The branch has tension wood and compression wood. The only thing which supports the branch weight is tension wood. When the decay in tension wood caused tension wood to fail, the tension wood went one way and the compression wood went another, causing the horizontal crack, splitting the top from the bottom for about 3’. The compression wood which had been the bottom half of the wood now had to carry the weight. It failed and broke at a different place about 12” away.
Think about cutting big tulip horizontal limbs. You can undercut them quite deep without failure. The bar will get pinched before you get to see just how far you can cut. I think if you can keep the bar free, you can cut 50%+ before failure because that is compression wood. It is not supporting weight. On the other hand, when top cutting without an undercut, it seems like the bar has just barely touched wood when BAM!!!, the branch lets go. TENSION WOOD IS ALL THAT HOLDS THE BRANCH UP.
So what does this all have to do with hinges?
On a side-leaner, the fibers on the side of lean in a hinge do nothing.. nada..zip.. to hold against the side lean. They are all compression. So leaving more tension wood on the far side of lean, in the hinge, will make it stronger in it’s ability to hold against a side lean.
To me this is a huge revelation. I Am looking foward to field testing.
I Am thankful to Spidy and Dent for being instrumental in this revelation.
God Bless All,
Daniel Murphy

 

[TheTreeSpyder]

i have read the opposite somehwere, stating that the compressed wood keeps it up... both have validity i guess, but mostly as background as to why to always use both!

i always express it to people that, they would rather have belly damage (under lean) rather than back damage (top of lean).

i see it as the top as the release side, where i would cut in to cut it down, and some of that work is already done! i believe the top of the parental joint is the most leveraged pull on the system, damage here is on a 'pressure point'.

 

[o0_TreeMan_0o]

".....Jerry cautioned me about nicking the top of the limbs, where breaking a small amount of tension wood can cause large limbs to fail....." Ralph Stearns Dyer Redwood Climb

 

[murphy4trees]

Spidy ,
you may be right about compression wood tending to "push" the wood up. Some experimentation is in order.
And that does make me think, relative to hinges, that the removed compression wood from the side of hinge (towards lean) should be replaced with a shim or lightly driven wedge, to continue to keep pushing up against the lean and prevent the hinge wood from being pulled on by the tree, trying to sit down on the kerf. What do you think? Maybe the wedge should be driven hard to lift against the lean.
I know in making wood bows for archery, that if the bow's face's outer growth ring, which would be the "top" of the tension wood, is cut through or significantly damage, the bow is trashed. This further verifies the relative "strength" of the tension wood.
God Bless,
Daniel

 

[TheTreeSpyder]

Not sure why you would do that,
i think one of the reasons to make knotch is to allow force to flow, to take out that 'chock' from the rolling force,
so now we are to suspend that for what reason?

 

[murphy4trees]

ok, I've got a side leaner, so knowing that the tension wood is much stronger than the compression wood in holding against the side lean, I remove wood from the compression side of hinge leaving the tension side a little beefier, wider, thus a little stronger angainst the side lean while providing the same resistance to folding into the face as a thinner hinge running the full length of the notch.
So I have now removed some of the wood fibres on the compression side, leaving a kerf, or empty space. The side lean and wieght of tree are pushing into and want to close that kerf.
Remeber it was you who said the compression wood is "keeping it up". What is the effect on the hinge of loosing the compression wood? Does that create a side pull on hinge?
I Am suggesting that the wedge, when driven into hinge from the side, will do the job of the compression wood without adding to the resistance to hinge folding into notch. And maybe even by driving the wedge, again sideways so it runs in parallel to hinge without entering notch, I can create a force to lift against the side lean.
Love that concept... and is it correct?
God Bless,
Daniel

 

[Kevin]

Are you guys trying to create what has already been established for generations?

 

[TheTreeSpyder]

Hmmmmmm, yes that is one angle, but if it was pulling down the spread would come from the opposite axis of the pull(topside), that would be the first most noticeable movement at the top, from being pulled down, for it would be the point of most movement. Thereby the most leveraged point to stop such movment, would be the holding wood there.

i think in some ways what u are pushing towards could be a type of dutchman if used during the cut; whereby it could have a push up off this step as it swept. But i think you will find the most support at the first incidence of seperation of the pull- on the cross axis. Duthchman's are real dangerous, i think most of their lessons in them is what effect not to put into your cut as you assemble it,a nd how you might sloppily trip into something similar and the massive forces of the slamming faces as they hit a blocked side.

If the rot was just write as the holding wood on top was devastated totally, and the bottom so sound, i guess that might werk, not an expert, jsut a guy that has been able to turnit over in his head and hand a few weaks more

 

[Kevin]

If I have a need to drop a tree exactly where I need it, a rope and guy(s) would be the order of the day.
Other than that, wedges will steer a falling tree but once that hinge is broken you ain`t going to stop it or steer it somewhere else without some added help.
To use a conventional or Humbolt on a leaning tree under stress without plunging the tree is a recipe for death, especially if you`re trying to steer the tree down to the ground by frantically hacking at it with your chainsaw while it`s falling.

 

[TheTreeSpyder]

This technique is very powerful, by placing fibre in the back row, stretching it to the front, immense forces and pulls are built up in this super strong fibre that we build from.

This pull when placed at the most leveraged positon, at the widest part of the stump, is a standard practice, in some arenas.

These same properties can be put into use in the tree, fighting a downward pull, as you fold across. Using the hinge to focus at the delivery point, and the holding wood untop to help fight gravity on the other side. Through a wide face, it can carry quite a percentage of a load through a high sweep, rope assisted. But it will be an extra butt support through that almost horizontal sweep, then if the green end is heavier, it will lift the butt end up as it ballasts the movement of the green end.

In case ya missed it in another part of this site, here is a passage from some of the 'propaganda' about this 1974 book:


Crown Zellerbach

"This book has been used for many years to train firewood cutters, loggers and personnel of various federal organizations (U.S. Forest Service, Bureau of Land Management, Bonneville Power Administration, Western Area Power Administration, National Park Service, U.S. Department of Labor (OSHA) and numerous state departments of forestry. Professional Timber Falling is the most comprehensive text of its kind available. It covers the full range of topics from bars and chains to the physical forces affecting the tree. An in-depth analysis of such topics as, the holding wood, backcut, undercut, stump shot, side boring, notching, jacking are thoroughly discussed and vividly illustrated. Quite simply, Professional Timber Falling teaches all chain saw users how to make it home safely every night through the use of safe, efficient and proper work practices."

 

[murphy4trees]

Kev,
The image brought to mind by your words " especially if you`re trying to steer the tree down to the ground by frantically hacking at it with your chainsaw while it`s falling." made me LOL.
We've touched on a bunch of points on this thread and it's a bit challenging to keep them all straight. And we do nothing of the sort... though i might just speak for myself.
Spidy isn't a tree surgeon.. he's not even an arborist.. he's a dancer.. a tree dancer using block, tackle and saw, sharing the stage with the standing people of the green nation.

And there is really nothing new here. We are sharing interpretations of Dent's book. That holds the wisdom of generations. I believe that if this technique works then somebody has already thought of it.

As far as plunging goes.... come to think of it..that may be the best way to set up this off-center hinge.

So again I ask:
R U a logger.
I got some videos on loggong by int'l paper. Pretty decent.
Logging is a different game altogether than what we do in suburban tree service.
And there are plenty of transferable techniques... we just think differently though, very differently.
God Bless All,
Daniel

 

[murphy4trees]

Spidy,
Nice diagram.
I was actually thinking of a hinge where the fibers at point of triangle (left end of hinge as per diagram) are cut altogether leaving a light blue area, (similar to one on opposite side of hinge made during precutting) to be filled with wedge.
As long as the hinge is left in triangle all the way across notch there is enough compression wood to "hold up" side lean.
Do you think there are any advantages to cutting and wedging as above?
God Bless All,
Daniel

 

[TheTreeSpyder]

Ummmmmm if the slamming faces used it as a step that closed faster than the other side, therby pushing to the other side. The tearoff would start from the left and go right, as the right still held on.

Perhaps.

But,it has been my experience, that the corner of fibre material you are violating is the most leveraged position of the hinge to leverage against the tree spinning on holding wood, and ending up at 2:00 rather than 12:00 on landing. The holding wood technique is that strong ! It can overpower very much weight, and can pull around that much sometimes. So, in some situations, a lil fibre anchoring that corner is very important for 'tying' down (with fibre) that corner to stabilize a straight lay, for according to 'thee book' you always want to lay the tree into squarely into the face of the hinge, and adjsut the holding wood across for the pulls accross the hinge.

Now i have totally violated that corner, with a lot of weight over there on the L. that kept the tree square, Butt, if the 'triangle ' has a lot of rear fibre (pulling hardest) scheduled at fold; it can still pull to far without that L. 'anchoring, squaring' corner of fibre. Whereby, a sleeker triangle, without as much rear fibre pulling hardest, wouldn't spin. i guess weighting these things out is a matter of experience, guess it is time to hit the field with it.