Hinge_Test_2

[@seandunlap1743]

Great example of the mechanics of the tree fibers under the given stress. I'm really enjoying your videos and feel that they will help me be more safe. Thanks!

[@terryhale9006]

Thanks Sean!

[@imduncanmajunkin]

I too sir, am fond of beavers. ;)

[@wakayama1991]

fascinating series, simply fascinating! thank you so much for your time in making these!

[@MrAbsentdriver]

You are a great help for me understanding my line of work. I wish you had been a school class, lucky i have access to your channel. Please keep the knowledge coming.

[@treemanclint2883]

I want to commend you for the time and trouble to illustrate this, however, there are a few points that could hit upon for those situations where ultimate control are required. As most of us who fall big timber professionally know, once a tree gets to about 15 degrees of fall, the course is set. That's just fine in most situations, and often adventurous to have a hinge break at a high angle when working in a closed canopy with high value trees. If the hinge is to good and the tree roll's or limb strikes another tree, then severe fiber pull or face slabbing are likely. Moreover, the overall bending classification of the species at hand, the condition of the tree, age, size, growth pattern of stump, lean, compression and tension wood, degrees of face opening, thickness of hinge, height of back cut in relation to face, depth of face cut (which directly affects how much fiber in the hinge is parallel or perpendicular to the bend), season, weather, and probably ten other factors dependent of the situation. Point is what is your personal needs and goals. If you just need to remove trees in an open area that have no real value, any of the basic techniques work. If you're interested in being a professional timber faller cutting high dollar timber trees, or as a professional arborist working close quarters to power and structures. Then you must be like a sniper; armed with a saw instead of a gun, there's more to it than pulling the trigger.

[@terryhale9006]

Clint, No disagreement. This video was made after I got a bit annoyed with someone claiming a 70 degree notch was required so that the direction of fall could be controlled by the hinge "all the way to the ground". I definitely agree that the course is set once the tree has some momentum. Terry

[@rolyf100]

I love this stuff! One day you will fall into a pond while carrying your favorite axe and wedges. You will refuse to let them go. As you sink towards the murky bottom for the third time you suddenly feel a group of warm noses pushing you towards the shore. It will be the beavers for whom you cut down that aspen. Nature is like that, Or not.

[@terryhale9006]

They will only push me if I drop the heavy stuff. ; )

[@neightjay]

Very informative, thanks a bunch. Trying to learn as much as I can from your videos. Thanks for putting in the time to share all this valuable information. 👍🏼

[@terryhale9006]

Thanks Neight.

[@kenpeck9165]

Great video! Thank you for taking the time to explain!

[@xyzct]

Terry, Terry, Terry ... I'd expect at least three significant figures from a fellow like you.

[@terryhale9006]

Old eyes.

[@tsieglieh]

Geez amazing work, thank you!

[@peterk.9994]

Nice video. Very interesting to see the incremental steps leading up to the hinge failure. Yep, you certainly won, but did you have a hidden ace up your sleeve??? ;-) I would guess that the fact that the failure occurred almost exactly when the notch closed completely was more than just pure coincidence. With enough experience, etc., I would think that, within certain limits, one can "fine tune" exactly when hinge failure will occur by adjusting the angle/size of the notch opening, among several other variables. Of course, there are variables you can't control, e.g., specific tree characteristics such as wood density, etc., so the prediction can only be approximate.

[@terryhale9006]

You are correct....in each regard. Clearly the test was rigged. As I watched the crushing close the hinge, I was wishing I had used a wider notch. The crushing was also influenced by the pressure from the belay.

[@robertgreen2288]

Agree with tree man. I did enjoy the slow motion.

It was not the flexety of the wood that limiterad the hinch. It was the angel of the fas cuttung. A asp kan some times be horisontal to the grund and still have god grupp to the stump. Flexebilyt inkrese if the hinch is thinn. The holding capasety of a side lednin is dekresing with thin hinch. Stil Inpressning setup. Thanks fore god videos.

[@williaty]

How does the 37* hinge failure angle demonstrated here reconcile with the "Limits of Hinge Performance" video that demonstrated the hinge should fail in tension with just a few degrees of movement?

[@terryhale9006]

williaty Hi Will. There is a difference between the hinge experiencing cracking and the hinge failing. The first snapping of fibers, heard as cracking, does indeed occur after just a few degrees of movement. That snapping of fibers can be heard at numerous times in the demonstration video. Failure of the hinge only occurs after ALL the fibers on one end of the hinge have snapped. As stated in the introduction to "Limits of Hinge Performance", "..the hinge is largely compromised and ineffective at controlling side lean once the tree has fallen thru about 30 to 45 degrees." The 37 at which the demo failed falls right in the middle of that range. With a brittle wood like dead, dry pine, I would expect the failure to occur at an angle near the bottom of that range.

[@moikechan]

I'm just as curious as can be to know/see how the remainder of the line was payed-out. I would expect the tensile forces nearing the failure angle were very high and that there was actually a reactive compression force component driving the butt of the tree back into the step on the hinge. All I kept thinking as the angle got shallower and shallower was "He's going to have to cut that rope and run for cover".

[@terryhale9006]

You are correct, Mike. The tension forces were very high. I had something like six wraps on the PortaWrap to hold the tree back. When the tree finally fell sideways (into another tree), I still had it firmly held by the PortaWrap. Since I was back by the PortaWrap, I never needed to run, as the tree was falling away from me. You are also correct that the tree was being pushed strongly back into the step. To put things into perspective, I very nearly burned myself when I touched the PortaWrap to undo the belay line after stopping the video. The potential energy of the tree got turned into friction energy, and that energy went into heating up the steel PortaWrap. I nearly burned my line, even though it never moved fast. The risk of burning my line is the reason I decided not to re-run the test with with a more open notch. That one line cost me around $200.

[@hosocat1410]

Outstanding work! Thanks. I have a question about hinge performance. Maybe you've answered it in another video. Let's assume you have a perfectly symmetrical, perfectly vertically balanced tree. Or just say a perfectly vertical telephone pole. You have cut a face notch, and you have back cut to the precise dimension of the hinge and have supported the gap in the back cut as you cut it, say with a spacer the exact thickness of your saw blade without the spacer exerting any vertical force on the tree (pole). Once you have achieved that theoretically perfect condition will the tree fall in the direction of the face cut, and what causes it to fall. Is it because the fibers in the hinge start to collapse and the only way for the tree to go is the direction of the face cut? Sorry this question got so long winded.

[@rizdalegend]

since the notch angle bottomed out did this cause the hinge failure? conveniently at 37 degrees... haha. glad I stumbled on your channel, have watched all your modules so far. subbed and thanks for the great teaching

[@terryhale9006]

I wish I could say it didn't, but I think (1) it played a part and (2) the hinge really was just about to go anyway. I've felt somewhat chagrined about not having used a wider notch and have wanted to repeat that test with a variety of other trees. One reason I have held back is that my PortaWrap got REALLY hot. I hadn't anticipated that and actually got a minor burn when I touched it. My rope didn't like the heat either!

[@Troglodyte-gz4fm]

@@terryhale9006 I agree with Aaron above as the hinge goes from tremendous compression to tremendous tension in a moment as the notch bottoms out and becomes a lever, tearing the weakened fibres out; I always prefer using an open faced notch for no other reason than my own misguided intuition. I would love to see you repeat the procedure with an open faced Erikson notch and compare results. Great videos, and thanks for taking the time to produce such helpful material.

[@Zlinky111]

@@terryhale9006 it was still excellent, and very educational. 👍👍👍😃

[@TrailsTrailsTrails]

For science! And for the beavers, too.

[@Dingbat217]

Great experiment! :-)

[@terryhale9006]

Thanks Morten!

It was not the flexety of the wood that limiterad the hinch. It was the angel of the fas cuttung. A asp kan some times be horisontal to the grund and still have god grupp to the stump. Flexebilyt inkrese if the hinch is thinn. The holding capasety of a side lednin is dekresing with thin hinch. Stil Inpressning setup. Thanks fore god videos.

[@terryhale9006]

Thanks Hakan. I do wish that I had made the face cut at a larger angle. A thick hinge will begin to tear. Then it will become a thin hinge and have more flexibility...and, as you wrote, less capacity to hold the side lean. I may have to do some more tests.