Pecan Hinge Failure -- what did I miscalculate?

[Marc-Antoine]

The nipping leaded to the failure as you cut nearly all the holding fibers. Before nipping the hinge, you should have figured out why it was still standing. The main point.
Pulling by hand, even with a 3/1 MA, doesn't give you much force (not to say nearly zero force), but the truck should have done it. Excepted that a stretchy line is difficult to load with a good guess visually of the pulling force, and I bet that you stop the pulling before you get a real force on it. I did the same mistake once on a poplar top with a stupidly cheap "very strong" rope given by the owner.
The back cut looks clean, no forgotten fibbers in the middle for example, and there's plenty enough wedges. The rope is in the middle of the tree, so not too bad. (Edit : quite a bit low for a middle!).
Many long limbs are on the side of the service lines, but that's not a giant. Overcoming this back load is doable with the wedges and the rope.
Maybe you didn't stack enough wedges to push the cog over the hinge. Two levels of wedges seem a bit short to me with an unbalanced crown.

An other good reason to be stuck like that is having a limb or two under the lines, so you actually try to lift/pull the lines with the tree. With the leverage, it doesn't need a big limb to hold a ton, even a well placed twig can do it.
Oops, I posted too late and didn't saw the previous posts!

 

[pantheraba]

I have pulled with a truck before on a back leaner and got concerned I might induce a barberchair with a hard pull. You could chain/strap above the facecut if you aren't sure how hard to pull.

But...if your pull line is too low and you give a hard pull you can pull the lower part of the tree out from under the top...basically break it off at the back-cut/hinge.

I use a throw line to get a good high pull and always test pull to see what kind of force it takes to move the top of the tree. Get that pull line higher for sure.

This is how we learn, for sure....thanks for posting.

 

[MasterBlaster]

The best thing that this will never happen to you again.

Hopefully!

 

[Raj]

I often work solo, maasdam or 2 are great for my pulling needs.

Great advice already given.

 

[theTreeSpyder]

Shouldn't really be swimming alone...
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I woulda looked into how much a free line drop by power company is (at least locally free).
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I think pix roughly all the same direction, is best. And direction noted on even more.
And should always reveal purposefully weight balance front to back AND side to side of tree before.
Also ALL of hinge on stump and butt end, both sides after.
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Deeper face, as said, to undermine CoG more, AND wider breadth across hinge for side control thinner hinge too.
Higher leverage pull point, possibly grabbing several central close leaders as one for higher grab, maintaining balanced pull and rigidity of input to hinge pivot.
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I think some kind of Dutchman in face seen from that unique hinge, preventing flow forward.
>>Stacked hinge pic, right hand of viewer with the shelf under the run to jam works.
Like Gordian Knot, or Chinese finger puzzle; the more force put into it, the more bound against you.
Then 'too happy' with saw, still couldn't go forward, door still closed.
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Would have had to have lots of backlean to lock against even 3/1 hand pull, let alone truck, let alone wedges.
>>it was in a bind I think from face close/blocked path logically (if got no movement or just half a degree) and visually shows also.
This is specifically where I think view of other side of butt/hinge half would be good forensics measure (hidden in grass).
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Instinct was right, wedges alone was flagging bound some how, especially with almost Zer0 movement.
When in bind should have backed up lightly, not forged forward
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Too happy with saw for me is to the observation, that before cutting tree is already not going were you don't want it to go.
We talk of making a Tapered Hinge etc. but really we just aren't cutting it out. Tree is already using same key fibers not to fall where don't want it.
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Don't want to be in danger , but would look to back cut most on don't pull to this mo'fo side.
Seems where pulling into own pinch....and freed Willie and hung on one band/chord twisted as couldn't go forward.
Always want even just a tuft/chord of fibers as anti-spin to extreme opposite sides unless really trying for twist/swing-dutchy type sweep across.
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Do you know what they called the greasy, tough guy biker after he dropped his new ride?











An experienced rider!

Edit:another rope trick for force would have been to wedge/lock truck and jerk ACROSS rope sharply.
In such a bind probably would still been reflected back thru bind to lock against ya in this instance.
But, would provide a VERY high amplitude pulse thru line.



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especially if Dutch all the way across and is no seen cuz on butt end

 

[MasterBlaster]

Shouldn't really be swimming alone...

 

[Tree09]

When you are pulling a tree, or using wedges for that matter, you are applying a force, which is actually called torque. Torque is measured in the us as foot pounds, and the equation is torque = distance x force. If you double the distance the hinge to the pulling point, you double the force. Assuming you didn't hook a limb under the wires, you needed to overcome back lean, which can also be calculated as torque. Using a green log weight chart, you can estimate the size and length of limbs, and therefore it's weight. You can then guess the center of gravity for said limb, and then use a tape measure to get the distance from the hinge to the center of gravity to calculate a torque measurement for that limb. The entire weight if the limb will behave as if the entire weight is at the cog (Center of gravity). Limbs out the front will help, while limbs ot the back will hurt your efforts. Side lean can also be calculated, because the limbs will all add up according to their torque vectors. Your applied torque has to be greater than the torque of the backlean, and if needed your side line will have to be equal to or greater than the side lean. Maybe this picture will help.

You also should do a sample pull, even before you cut anything on the tree. If you can cause the tree to lean before you even get a cut in it, you likely have control. If you are pulling and it doesn't move, you are underestimating the backlean and are likely too low. When doing this, line up something in the background or foreground to watch if it's moving, because staring up in the sky you can't tell anything. August had a video where he goes over this in detail if this is confusing.







This one is number 3, don't know what i did lol

 

[Jonny]

Owww! My brain hurts Kyle!

I like the maasdam suggestion. If you can't have someone pulling on the rope, then pretension it and use a maasdam or prussik to capture all that tension. Maasdam would work well WITH your 3:1 z-rig.
Yes, the line is set too low. I think I still could've put it where I wanted with the line at that height, though I would've set it higher.

Use the wedges to keep from pinching your saw if you need to, but trust the rope.

 

[Tree09]

The same calculations are used for figuring the cog for critical crane pics and rigging, as apprentices we were taught that stuff and more. That's what rigging is in the construction world.

 

[Burnham]

Robert...I think you might go back to the last pic in your opening post...read your yellow text...follow that thought. It's the only thing you got right on this effort.

I know this sounds quite unkind, but it would appear this work really isn't something you are growing into. A wise man would withdraw from the battlefield before he is completely decimated by a superior force.

I'm sorry to be so blunt, yet again.

 

[MasterBlaster]

Meh - I look at it as an experience on the road towards becoming an expert.

Lord knows I frigged some shit up during my learning curve!!!

 

[Burnham]

I'm probably being excessively ungenerous. We all have made mistakes, surely.

 

[MasterBlaster]

Shit, I've been fired - rehired, nearly killed myself - several times! No cameras or videos back then, thank Thor!!!

 

[gf beranek]

Now you're an expert! Congratulations.

 

[Tree09]

Or at least get someone to learn from. There is virtually no room for friggin' up and living to tell the story in this line of work, and being self taught makes it even harder and closer to the edge. Virtually nothing you did there was correct, and you hit powerlines and a propane tank. You were very lucky to tell us about it, and it was a small tree. You were uncoachable when you tried to dismantle a tree standing on your truck with a polesaw, and hopefully you open your eyes now. You almost died, and I'm not sure you fully understand how close you were.

Now having said that, you are still in the hunt, because you aren't dead. You need to get with someone who does this for money, and actually learn wtf you are doing. Your former day job didn't give you the skills to pick up on this super quickly, so you need to get with someone who can teach you this trade. If not, I'm afraid we'll find out what happened via a news article. Please get some help learning this

 

[MasterBlaster]

Now you're an expert! Congratulations.

As if. MANY more frig ups before being bestowed THAT title.

 

[theTreeSpyder]

A wise man would withdraw from the battlefield before he is completely decimated by a superior force.

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Mr. Robert, i think we could say; should say, tried not to say;
Ya ain't ready to ride point, let alone fly solo.
It would be best if you were under someone's wing.
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Playing with pure power, and can only tease the lion so many times without checking gates to cage before drawing short straw.
Arm chair quarterbacking can be fun exercise until you end up a brownish grease spot .
i don't think anyone here really learned what you did off the internet to get started!
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edit, yeah what Kyle said!

 

[MasterBlaster]

Not ready for point yet, for sure.

As you were.

Kenny! I don't think I would call that tree in need of pure power!

 

[Jonny]

Exactly.
Take the fall. Go be someone's green groundie for a while. You can't learn this without one on one interaction. Teacher and student.
I wish you were closer, I'd spend a day or two with ya.

 

[mike in pa]

I often work solo, maasdam or 2 are great for my pulling needs.

Same here. I work alone so two Maasdams for pulling.

 

[Burnham]

The pulling was the least of Robert's problems, I fear.

Brother, you can't yet put in a felling cut worth a litre of warm piss. THAT'S your main problem, still. I won't even begin to itemize the many other mistakes you made on this little bush of a tree. Others have done a fine job of that already.

 

[pantheraba]

I looked at the pictures again....I have made some ugly cuts, too...un-level. I think those cuts could have worked except for skinnying up the hinge to the point of NO hinge.

I think Carl said it best...looks like the hinge was cut down to nothing.

And the pull rope was below the COG of the tree...there were lots of limbs above the tie point for the rope...a lot of weight in those limbs that had to be overcome.

A compounding of errors that added up to catastrophic failure.

 

[CurSedVoyce]

When working above your skill set, expect failure. In doing so, you will often choose staying in your skill set and passing on the work to someonevwith the skill set. And/or, learn to mitigate the risks in your favor to elevate you skill set.
Failure is expensive.

 

[MasterBlaster]

Slap your ugly cut in, then give me enough power.



Robert didn't use enough power.

 

[SeanKroll]

How thick was your original hinge as a percentage of diameter? It was simply too thick (and sloping), then cut off on one side, falling to the other, as expected. The tree did exactly what you asked it to do. Be happy you're neither crushed beneath, or injured getting out.

How much leverage did you have at the crotch (distance from hinge to crotch)?
How much could you have gotten?




If you heart is pounding that much, STOP!!!!!!!!!!!! Ask "Is this the time to make critical judgments?".

Calm down.



Remark the hinge thickness!!!!!!!!!!!!
Cut a little at a time.

Then Gut The Hinge/ 'Tickle the face' from the front (cut with tip of bar in middle of hinge to reduce amount of fibers that are resisting the fall) WITHOUT getting your bar trapped. If you get your bar trapped, and the tree is falling, run!