Forcing Hinge Strength

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TheTreeSpyder

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A lot of things in nature become stronger by challenging them. The wind blowing can make branches stronger, cutting buds can 'force' more flowers, a broken bone can heal to be stronger etc.

i think that if i am back cutting a horizontal limb to fold down into it's face; that the same limb (size and weight) that grows from center to 1o'clock, will fail with less fibre than if it grew from center to 2o'clock, because the more downward pull at that angle. So the same limb folds with more controling fibre at diffrent times, with more fibre when challenged. So by throwing a line over the limb far out at high leverage, and pulling down, you can force fold earlier, with more helping fibre. This is true with dropping trees also. Blocking catching on the same spar too, having the best pulling strategy pulling the load over on the stronger hinge, sometimes flexing all the way over before tearoff for the least amount of shock loading, for the hinge hands the load off to the rig more gently.

If you force a stronger hinge in a lateral, and that hinge is focused to target, with a triangle fibre at tearoff based at the top, you have forced a more strategically constructed and steering hinge to also be stronger too! Compounding its capabilities and slower moving, less shocking.

Throwing even a throwline over a rigged lateral and exerting 50# pull, 15' from the hinge will load up a 'temporary' 750# load on the hinge, if it is slowly cut, it will begin to fold at the leveraged load presented, the temp 750# is eased and the limb is slowly moving with a meatier hinge than it would contrive itself! Anchor to the ground 1 end of the throwline and place 50# on the remaining leg places 2(legs) x 50#(your pull) x 15' (throwline to hinge) for 1500foot pounds of temporary force on top of whatever leveraged force already exists.

As wee depend on the hinge more, we must consider more the individual rot, grain, temp, species etc. and other things that affect this part of the machine that we are attempting to rely even more-on.
 
Having a specific pattern of hinge at tear off, to use a certain way, can be maximized by making the chosen hinge pattern stronger, and all of it's pulls.

The hinge pattern stuff and it's understanding i fully credit to Doug Dent in Pro Timber Falling .Dent on Hinging Thread . i beleive my models of explanation, use turned sideways in tree to still fight pull and forced increase hinge strength all coincide with his book, that it has taken me years to fully appreciate!

The more we depend on the hinge, the more we depend on the strength/ flexability of the hinge fibre area due to conditions of species, individuality, temperature, decay etc. let alone the grain itself having knots, cat facing etc. Also the more we depend on the ancoring of the stump/limb. In a tree i will leave a longer stob to address later, so that the increased shearing stretching fibres don't carry there disturbance to the parent stem when really torquing hard on the fibresa nd asking a lot of them
 
Applied to blocking and catching, the better hinge delivers closest to target with bes braking/ support; just like rigging, felling.

Line is placed at highest height to flex over the slowly cut hinge with most leverage, forcing the meatiest hinge, with greatest strength to catch the same load. Sometimes a climber can stop just as the hinge is thin enough, and muscle it over some. Whatever travel he gets before freefall lessens impact. Guys pulling from ground is safer, easier, and pull can usually be placed at better leveraged position.

The more pull, the earlier the hinge flexes with more fibre, for more strength and hold on, for later free fall=less force to catch or run.
 
Hi TS, I see what your getting at. Horizontal limbs can be felled accurately by placing a traditional notch and backcut, then commiting it with a rope or simply pulling on one of the terminal branches in the direction of fall. This method saves the added work of chopping the limb back to a stub. It's just that the hinge wood tends to break sooner due to added gravity and doesn't pick up the speed that a vertical stem would.
An example would be a tree across the road at waist height. If a notch and backcut were placed on the correct plane the whole thing can be swung around to clear the road without having to buck the whole thing into pieces.
John
 

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