Second notch on a stem

theTreeSpyder said:

center of round; but also center is most likely to be stiffer less flexible fibers

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1/3 a good for hinge because not into stiffer center model;.

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I believe this is a common misocnception in the industry. When there is solid heartwood and maximum control is needed from the hinge I ALWAYS use the widest hinge possible... The difference between hinge strength in heartwood and sapwood is influenced by species and moisture.. HOWEVER I can show you a LOT of photos where the heartwood fibers off thehinge had the most control and where the largest whiskers...
The idea that sapwood held better was most likely a misinterpretation of fiber pull down the side of the tree, ripping out long strands of bark.. One might look at that and say.. these outer fibers had the most strength becasue they held the longest and caused the bark to rip and sometimes pull the tree of the lay... The only reason they ripped down the sides and the center fibers didn;t is becasue the center fibers had no where to go.

Your test is biased because when you cut the sapwood, the hinge isn't as wide as the uncut hinge. Like a lumber, the hinge's strengh on its side is function of the cubic of its length. Drastic effect with a small variation.
You have to take an other stump a little bigger in order to get a full 6" of heartwood.

So , the sapwood breaks easily ...

Interesting concept great. I'll check it out

theTreeSpyder said:

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This maxes out at center of round; but also center is most likely to be stiffer less flexible fibers
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murphy4trees said:

I believe this is a common misocnception in the industry.

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theTreeSpyder said:

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1/3 a good for hinge because not into stiffer center model;
BUT also, this puts the backfield of the hinge into widest center...
This, gives most tapered hinge leverage against side lean
>>having tapered hinge backfield fibers at widest/center
>> as farthest leveraged point of control from compressed fibers in hinge (under sideLean side) as pivot.

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What i mean is if any fibers are stiffer/less flexible, suspect center as others have stated
i have seen the drier centers, stiffer wood seems
but not sure about less flexibility but makes sense; going with other's observations.
(didn't mean that center is more likely to be stiff than not, but rather outside vs. center, center would be most likely suspect if stiffer fibers;
theory reversed somewhat in palms, with more water protected in center from hot beach sands reflecting heat)
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To me, centerpunch kinda covers that, but more importantly;
allows more fiber population to be forced in the extreme backfield of tapered hinge side against sidelean.
Center of hinge even if not stiffest, provides least side to side steering of sideLean

sotc said:

I think each situation would be different. I'd say bare minimum you should be at least a trunk diameter above or below the original cut.
Barber chair wouldn't be of concern without a pull line if it wasn't a concern before hand.

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^^^ good point....... In a NWCG Wildland Fire Chainsaws course they taught sawyers to be at least 1 to 1.5 the diameter of the tree above/below the original notch. Didnt say if above or below made a difference though

Welcome to the TreeHouse, Bo!

HolmenTree said:

Who cares about 6", just try it whether it's only 4" or 8" diameter......

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You !
That's what you said in the previous post. I just took the size you said as an example.
I mean, if you make a hinge on a 6" stump, then cut only 1/4" on both side, you lost 23% of the hinge's strengh (sideway), regardless of the wood quality.
That's not a valid test in my book. Yo can't have 2 factors with a sharp effect in a test and drew a conclusion on only one.

Edit:
Don't get me wrong, I don't say that your point is wrong,, just find an other way to prouve it acurately.

look at this hinge... where is the strongest holding wood ... the center or the sapwood???

Been down that alley with you a couple of times before, Ain't gonna walk it again.

All the European practice of gutting the hinge and relying on the sapwood to hold, done by thousands of experienced loggers since chainsaws came around just tells me, that you are wrong.

Just this: That ain't no tree, it is an overgrown sapling.
Talking 'bout heart and sap wood in that one is silly.

So, are you going to hit me with a study in a language you can't read, that actually ( Since I CAN read Swedish) turns out not to be about what you thought it was about, like last time we had this fun discussion.

Give it a rest, Daniel.

HolmenTree said:

For a test on any other species of tree, cut a 6 inch diameter stump 4 feet high. Cut a hinge as thin as possible then try and break it by pushing on it sideways. Good chance it won't break. Now cut the 1/4" or whatever the thickness of the sapwood is on both ends of the hinge.
Now it snaps off easily.
I've done this experiment many times on training courses of multiple different species green and dead dry.

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OK Stig,
I have no agenda here. I personally love to gut a hinge when looking to weaken the hinge on back leaners etc and feel much more confident about the holding ability of the side of the hinge in that case, rather than trimming the sides. HOWEVER that doesn't PROVE the sapwood is stronger.. It certainly is in a better leveraged position to fight side lean which may account for the practice of thousands of experienced loggers... I think there is a tendency to draw erroneous conclusions in such matters. I also recognize the limitations of science in scenarios where measuring and testing variables is difficult if not impossible... And like many of the more experienced arbs tend to trust my own experience more than some study by a PhD that lacks the practical experience to do this job.

And forgive me for not remembering our last exchange on the matter... I have some faint recollection is all... I will say though that if you want to say my analysis of the fiber pull in that picture does not apply because it is little more than sapling, would that reasoning not also apply to Mr Holmen's example above??? And that is just the latest tree that I pulled over. I have dozens of not hundreds of picture of hinges on all kinds of trees, big and small, live and dead, and may different species that show larger fiber pull in the middle than the sapwood... The one thing that may be different in my stumps than many others is that I use a high pull line and machines on almost all my falls, which allows my hinges to be much wider than many...

Certainly not trying to pick a fight here.. Just trying to learn something if indeed there is something to learn. My mind is open. I just haven't heard any reasonable explanations that would account for the bigger fiber pulls in the middle of hinges that would include sapwood being stronger...

It's all good.

thanks Butch.. that's so reassuring!

We use two different properties of the wood's fibers, in various ways to match the needs and therefor the technics : strength and flexibility. The value of both varies in heartwood and sapwood, species dependent too, but it's never all or nothing (except for rotten wood). Both are usefull in our game but it's difficult to tell the amount needed.
Just that sucks when there's a lack of them.

i would think the tree isn't really old enough to have aged, chemically altered, colored, almost powder dry heartwood.
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i would think the high rooster tail positions are forensically witnessable from how the Center of Gravity was placed/carried.
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i think in trees large enough, old enough to have 'dry' center heartwood;
less flexibility than wet/sapwood is logical.
Also, in such constructions, more likely to have highly leveraged sideLean as a primary consideration.
(Center punch 'heartwood' allowing more fibre population of tapered hinge extremes for sideLean control, so mite should do just for that).
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i've L-earned when to trust and standby my instincts on this stuff thru floods of naysayers;
i have also L-earned to trust some other's instincts when fits model and seem so logical.

HolmenTree said:

BTW did you bother to try my field test? Or are you just too stubborn to even think outside of what you already believe in.

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I definitely want to give that one a go.. just haven't been cutting saplings recently....

theTreeSpyder said:

i would think the tree isn't really old enough to have aged, chemically altered, colored, almost powder dry heartwood.
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i would think the high rooster tail positions are forensically witnessable from how the Center of Gravity was placed/carried.
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i think in trees large enough, old enough to have 'dry' center heartwood;
less flexibility than wet/sapwood is logical.
l.

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know it seems logical.. just not sure that logic plays in the real world.. Maybe the fiber pulls are longer in the middle becasue that is the place of stasis between the tensioned and compressed fibers on trees with even the slightest bit of lean and therefore the longer fibers are a result of hinge mechanics not fiber strength... That's a theory that might make sense...

Check out the hinge at around 8:00 on this video... pretty gopod shot of it.. now this is dead so long that maybe the rot was more effecting the sapwood than the heartwood on oak.. so many variables.. difficult to draw definite conclusions
have a good day everyone
<iframe width="420" height="315" src="https://www.youtube.com/embed/p04sxvuZu7E" frameborder="0" allowfullscreen></iframe>

that oak hinge

first stump I found looking through random pics

and another

There's a video of a fella,I believe is Australian,he does a huge 2 day removal,second day upon his ascent of the remaining trunk section,he makes all his face cuts ,to be used in negative rigging, on the way up. I looked for it but I cannot locate it,talking massive wood and about 15-20 notches in the stem. Seems loco but if you calculate for decay and loss of strength we still have alot of integrity remaining,hopefully someone else knows of the video,I thought it was ace tree but I couldn't find it...

here you go bro, its an ironbark likely eucalyptus crebra, seriously dense wood

<iframe width="560" height="315" src="https://www.youtube.com/embed/sYd5v03OnRY" frameborder="0" allowfullscreen></iframe>

Ace Tree has posted here.

But not much...

Nailed it Chris👍 that's why I couldn't find it,not ace tree😂😂 @13:38 for those that want to jump to it,I don't like it lol but it speaks strongly just watching it and actually thinking about the decay loss formula shows there can be great strengths remaining but we definitely need to be extra cautious of where the compromised integrity falls into play with our plan to work the tree.

Obviously EVERY tree is different,every climber is different,stay alert,aware and establish a good work plan on hazard trees for sure. Just sayin...