The Tree House loves TreeStuff!

how to fall back leaners

stig

Patron saint of bore-cutters
Joined
Aug 26, 2007
Messages
20,520
Location
Denmark
I've never seen a thin hinge hold better than a thick one.
But then your treefalling experience is rather limited.

Compared to those who log for a living.

Too thick a hinge will simply break instead of flexing.
A thinner one will flex and hold for longer.
All according to species, of course, in some, the fibers are so brittle that thin or thick makes no difference.

The triple hinge was invented to overcome the tendency of a too thick hinge to break, because of lack of flexibility.

Now you can go on one of your:"I'm the greatest, I've done things that no-one else in the World has" rants again, but that won't change the facts.
 

Bart

Treehouser
Joined
Jan 6, 2020
Messages
145
Location
GTA
Stig, I've pondered hinge physics(?) for a while trying to visualize the action. Best research I've turned up is mixtures of some degree/progression of compression failure - folks usually say, before - some sort of progression of tension failure on the back side of the hinge. Ending with a face closure for the final tension failure.

My chicken/egg is during the fall does the hinge evolve itself to eventually effectively become a thin hinge mid fall?

Pondering. Enquiring minds want to know. Penny for your thoughts.
 

stikine

Treehouser
Joined
Mar 24, 2020
Messages
517
Location
Southeast, Alaska
Bart, regardless of the method, consider supporting the compression side of the hinge with a wedge prior to that back cut. I should post as diagram of what I am talking about.
 

stig

Patron saint of bore-cutters
Joined
Aug 26, 2007
Messages
20,520
Location
Denmark
Stig, I've pondered hinge physics(?) for a while trying to visualize the action. Best research I've turned up is mixtures of some degree/progression of compression failure - folks usually say, before - some sort of progression of tension failure on the back side of the hinge. Ending with a face closure for the final tension failure.

My chicken/egg is during the fall does the hinge evolve itself to eventually effectively become a thin hinge mid fall?

Pondering. Enquiring minds want to know. Penny for your thoughts.
Very much species dependant.

On a Hornbeam I can see that happening, on an Ailanthus, not.

Long, strong fibers versus short brittle ones.
 

stig

Patron saint of bore-cutters
Joined
Aug 26, 2007
Messages
20,520
Location
Denmark
Bart, regardless of the method, consider supporting the compression side of the hinge with a wedge prior to that back cut. I should post as diagram of what I am talking about.
What you are saying is the exact reason the Whizzy/Sizwheel, whatever works so good on extreme side leaners.

The backcut on the compression side is level with the bottom of the face cut ( Traditional, not Humboldt), making it harder for the fibers to crumble under the load.

Lil' derail, but not uninteresting.
 

murphy4trees

TreeHouser
Joined
Nov 28, 2008
Messages
3,145
Location
Philadelphia PA suburbs
  • Thread Starter Thread Starter
  • Thread Starter Thread Starter
  • #32
Too thick a hinge will simply break instead of flexing.
A thinner one will flex and hold for longer.
All according to species, of course, in some, the fibers are so brittle that thin or thick makes no difference.
While I have seen a very few thick hinges explode and fail completely, that is much more the exception than the rule. On the other hand, I have seen thick hinges hold in amazing ways in very poorly hinging species, such as silver maple, norway maple and white pine.
I have seen so much of that that in so many trees where thick hinges worked so well that there is no way I would ever say that a thinner hinge holds better than a thicker one. I have heard that said by loggers such as yourself who obviously have dropped a lot more trees than I ever will. And there is no science to my knowledge on the subject. SO then, we must ask, what causes the discrepancies. Perhaps there is a bias because a thick hinge won't work with wedges. Perhaps the use of a pull line with enough leverage and force to trip a thick hinge makes a difference, but don't loggers use skidders with 50,000 lb winch?
 

murphy4trees

TreeHouser
Joined
Nov 28, 2008
Messages
3,145
Location
Philadelphia PA suburbs
  • Thread Starter Thread Starter
  • Thread Starter Thread Starter
  • #36
If he shifted his feet a little he could have held it. What a great try.
Ya, by far the worst move he made was not getting out of there.

ps another wedge pounder screw-up. I would have had two ropes in that tree with heavy machines on both because power can do what skill cannot!

And my hinge would have been 4-6" thick with the guts cut out
 
Last edited:

theTreeSpyder

TreeHouser
Joined
Feb 12, 2016
Messages
534
Wow, that is where a rope pull beats wedging for sure;
Too thick would have held..
but if we stand in the way of that fall can we then stop it????
.
Looks like brought hinge pivot back as far as could;
but still have straight up fairly balanced pillar as main and 1 wing as smaller back lean weight w/nothing pulling forward to offset.
Main most of is in front of pivot, but arm seems has more leveraged distance backwards..
Still folded on the loaded axis given by hinge profile, just wrong direction/breached on that axis.
.
Wedging trigger backwards fall?
Did wedge pop back out to give room for this?
facecut?
.
Should have had help,
to pull with truck tied balanced pull to top of each arm/lever; probably would not take much to offset balance to other way on hinge.
Have overwhelming force then, just gently applied/metered.
i assume it would have cleared that other tree.

Not really a drinker, but perhaps a good night for it!
And if weren't out there swimming alone, not sharing out part of the money; could might have a drinking partner.
Why would you do this alone?
Looks like must be something in the way, even if it is the street that traffic should be blocked on, but that would take paying a helper..
.
arborist_fails_movie_slice.png
.
 
Last edited:

murphy4trees

TreeHouser
Joined
Nov 28, 2008
Messages
3,145
Location
Philadelphia PA suburbs
  • Thread Starter Thread Starter
  • Thread Starter Thread Starter
  • #40
While I have seen a very few thick hinges explode and fail completely, that is much more the exception than the rule. On the other hand, I have seen thick hinges hold in amazing ways in very poorly hinging species, such as silver maple, norway maple and white pine.
I have seen so much of that that in so many trees where thick hinges worked so well that there is no way I would ever say that a thinner hinge holds better than a thicker one. I have heard that said by loggers such as yourself who obviously have dropped a lot more trees than I ever will. And there is no science to my knowledge on the subject. SO then, we must ask, what causes the discrepancies. Perhaps there is a bias because a thick hinge won't work with wedges. Perhaps the use of a pull line with enough leverage and force to trip a thick hinge makes a difference, but don't loggers use skidders with 50,000 lb winch?
@stig this is an invitation for you to reply with some intelligent response that brings all your years of experience to the conversation. That type of conversation is the best part of these forums. There is far too many personal attacks and far to little insightful information these days.
 

stig

Patron saint of bore-cutters
Joined
Aug 26, 2007
Messages
20,520
Location
Denmark
As for intelligent response, I'll never come near your mastery:

"
nothing you've done has impressed me I've done stuff that you have never done I put trees on the on the ground in a way you can't even imagine I'm not bound by your rules that it has to be perfect it has to look perfect the saw has to be perfectly sharp.
For me it just has to work.
I've been putting videos up for 10 years and they've all worked every single job back leaners front leaders experimental notches, Complex rigging, And cutting techniques that have never been shown or published in any other form. "
 

Mellow

Treehouser
Joined
Oct 13, 2017
Messages
2,145
Location
Sunshine State
Haha!!! You had me fooled for a minute there. I didn't see the quotes and I thought, "Dang, Stig is starting to sound just like Murphy now."
 

Sven

Treehouser
Joined
May 22, 2020
Messages
178
Location
Maine
Wow that video!! I really hope I never do that, shit happens but wow.
 

flushcut

TreeHouser
Joined
Jan 15, 2011
Messages
15,206
Location
Delavan, WI
Lota tree to be wedging over. So he was planning on dumping that in the street?


Last heavy back leaner that I dumped whole was an elm. Wedges, a 20ton jack, and 200' of 5/8" Stablebraid to the mini with near perfect line angle.
 

Nutball

TreeHouser
Joined
Apr 4, 2015
Messages
2,169
Location
Mt. Juliet, TN
Looks to me like possibly a pine tree, very thin hinge, and I think the wedge helped break the hinge on the camera side.
 

murphy4trees

TreeHouser
Joined
Nov 28, 2008
Messages
3,145
Location
Philadelphia PA suburbs
  • Thread Starter Thread Starter
  • Thread Starter Thread Starter
  • #48
No. The jack did most of the lifting. The line was drift control.
Elms have awesome hinging ability. Probably the best of any tree around here. Hemlock is also really strong too. I think tree jacks put out a lot more than 20T. I've never used one I just keep adding pull lines until I know it's good
 

Bart

Treehouser
Joined
Jan 6, 2020
Messages
145
Location
GTA
Here's some geometry to ponder for a back leaner hinge. Put the hinge dead centre and you have 50% (minus a tad) of the trunk diameter as the lever arm for the wedge/jack to apply up force x distance to make torque on the trunk. Put the hinge at the 25% location nearer the back (of the back lean) and you gain 25% shift of CofG for the trunk weight support, but now your wedges/jack are operating with 1/4 trunk diameter as the lever arm, so to create the same torque you need to double the jack/wedge force and thus double the tension you apply to the hinge fibres (yeah I know I'm neglecting the compression from the weight of the trunk, but with any significant lean it becomes the smaller factor). Now if you place your hinge at the 25% mark from the front (or 75% from the back) you've got 3/4 of the trunk diameter as the lever arm to make torque so 3/4 vs 1/2 is 2/3 the force required to generate the same torque. See where I'm going with this? If you could place the hinge right at the edge you'd drop the required force again. That would work on a square trunk but trees are round.

So basically I'm saying if you you place the hinge away from the back of the back lean, you gain lever arm and with the same tensile strength of wood fibers you can generate more torque before tension failure, or conversely gain more safety headroom away from tension failure of the hinge.

Aren't all the youtube back leaner hinge fails from tension failure of the hinge fibers, due to expecting too much from them? Seems so.


Or am I stating the obvious that is common knowledge and thus not spoken of much?

Just conversation. :)
 

theTreeSpyder

TreeHouser
Joined
Feb 12, 2016
Messages
534
To me is typical backlean query process as try to move hinge back to more undermine CoG
But move back that hinge at co$t of wedge leverage,
Can't have both at same time/reciprocal.
(and loose side to side control hinge width past center)
.
All i could figure was wedge bumped and something gave, wedge spit out etc.
then tree sat back with force? Trigger?
 
The Tree House Loves TreeStuff!
Top