Passive Forces

[TheTreeSpyder]

If you tie a line to an overhanging limb and hang 50# from it, if it hangs in the air, it needs 50# pulling back in the opposing direction (up). Place 100#, it still hangs etc.

The limb transmits enough BrakeForce through the line to suspend the weight. You can seperate the 2, and place a scale on the weight, it reads 50#; that is active force, like you pulling something. Hang the scale on the line, not much is gained knowledgewise, for BrakeForce is a pasive force, and to find the available force in this department, you have to pull on the limb till it fails, meassure that and say that the poor fella had so much BrakeForce.........

So passive forces might be a little elusive, but they can work for us powerfully and wonderfully adjusting automatically.

In felling a side leanning tree, we can provide lifts or pulls to target. 2 types of lifts/pushes 1 active, 1 passive, 2 pulls 1 active, 1 passive.

In dialing in the perfect balance to target in felling, forces to the left must be balanced by forces to the right. In active force choices, you must guess that right within the capacities of the hinge control. If you schedule passive forces to work instead or in tandem with active ones, the adjsutments to balance are more handled by the system automaatically for you. Also, generally in these systems the passive forces not only are stronger, automatic, but last longer.

A wedge gives you an active, rear, LeanSide, lifting(push) control option.

A high line an active, front, OffSide, pulling control option.


But, these are self adjusting by the tree:

A Dutch Step gives a passive, front, LeanSide, lift(push) option.

While a triangle hinge offers a passive, rear, OffSide, pull option.


The Dutch is the most potentially potent and deadly, while a triangle hinge is so pervassive, it is second most powerfull and last longest in it's action.

The quiet, self adjusting, overlooked hero is the triangle hinge of the 4. If not for all of this examination, then because in addition to the options, force, perserverance of this humble hinge; the other 3 strategies depend on it to help to their tasks! For even without them, this pattern is the hardest working in response to the oppossing pulls of the lean!

By correcting LeanSide to target with any real wedge, line, dutch etc. you invoke the passive, self adjusting force of the humble triangle hinge, as that is the pattern stressed by the lean to start! Let alone any ripping to that shape the hinge outright releases on LeanSide to visibly form the pattern.

:alien:

 

[John Paul Sanborn]

Originally posted by TheTreeSpyder
If you tie a line to an overhanging limb and hang 50# from it, if it hangs in the air, it needs 50# pulling back in the opposing direction (up). Place 100#, it still hangs etc.

The limb transmits enough BrakeForce through the line to suspend the weight.

I think of them as "loading force" and "holding force"..."breaking force" being either the friction that slows the load down, or my lard ass cracking the branch I'm standing on whilst starting a cut.

 

[TheTreeSpyder]

Well big'en if that was the mutual concension of terms i could go with that! i think there should be accepted terms for the prevalent and potent considerations.

i think the terms should be consistant to each other, as well as easy to remember/meaningfull.

Also would kinda go with accepted terms by recg. pro's, as well as physics etc. names when easy etc.

i kinda like the load/hold force concept, imagery and rhyming myself, wish i thought of it!

i get brake force from reading physics pages Joe has sent me over time; seems a farily consistent term actually..... also, the title of this thread!

And that would really kinda put cross refrece confusion with breakforce i'm afraid. Maybe shear point......or just strength?

i try to condense to one word as i think the common stuff hits me as one recognizable word pattern like that faster and syill mneomically, kinda from looking at computer stuff etc. too; sometimes setting up to fade back to the accronyms for such things idea....... But, i guess with BrakeForce that is a bad idea...............

C.o.B., {ooooooops}well i just got tired of typing that whole phrase that many times for something that prevailing in the system.

Load force i think is common, understood in form used.

i get side lean, buried kerf, hinge pivot, back cut, face cut, off side, control side, head lean, hinge strip, cross axis, mechanical analasis, causation& kerf, swing, step, unintentional types of dutchman's etc. directly from Dent's "Proffessional Timber Falling, a Procedural Approach". As well as my model for all actions in felling, even then turned sideways to rig. Wished i could have known that was what i was doing, kinda took the long, scenic journey!! Came back to that dog eared book many times, seriously recomend it, always been one of the more budgetable books too. 30 year old books get like that sometimes!

Guess iv'e kinda thrown in CenterFocal for what could have been gunned line or something for hinge face.

But i'd like to sort it out, have the lingo understood.

Dent's terms of pro-cedural approach, mechanical analysis, and causation has me convinced for some time now that these mechanics can be named and consistently found.

Took me a while to realize that the same drawings in one chapter on felling evacuated stress to target the same as drawings on safe log bucking, only turned per force direction. Took me further awhile to realize that in my rigging, i turned it on it's side again; making all the associations cleared it up very much.

Still an ongoing journey though! And will try to harmonize with accepted terms if anyone has any, from any field or experience.


:alien: