Triangle cut barber chair

davidwyby

Desert Beaver
Joined
Apr 25, 2022
Messages
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Location
El Centro, CA (East of Sandy Eggo)
IMG_4431.jpeg IMG_4432.jpeg IMG_4433.jpeg Logger friend back east sent me this after he gave it a whirl.

He said a bore and trigger would usually pinch but he has another method he’s going to explain later.

I wonder about a coos bay.

Maybe all irrelevant with the heart defects.
 
If you do the triangle cut the point formed by the two face cuts must meet at the front, doesn't look like that happened?
Also it's a bit on the big side for a triangle cut.
 
After listening to Jerry's story about the Coo's Bay cut, I spent many nights thinking about it. Let me present another scenario to you. How many of you have ever tried to fell a hard leaning tree 90 degrees from the angle of the lean? you put a big notch in it about 80 degrees from the lean and then back cut it hoping it follows the notch before breaking out. Sometimes it follows the notch, sometimes it breaks out early and falls to the lean. How many have ever had a barberchair occur in that situation? NEVER!!!

So with that in mind, it makes perfect sense why the Coo's Bay works so well. If you cut out the side wood, it is impossible for the tree to barberchair. This tree was a perfect candidate for a Coo's Bay cut. I have used it on trees but more often used it on heavy limbs and it always works. Forget the undercut, just cut in on both sides to remove half the holding wood without tripping it. Then cut from the back as fast as you can!
 
Bore the middle out, then set facecut with LOTS of reaming.
Pop backstrap.
End of story.
I think this tree might be a bit small for that, but maybe not. Either way, it would be a heck of a challenge to get a face in without getting pinched. LOTS of reaming indeed. Even with that, might not manage it.

I'd still vote for straight ahead full on Coos Bay, Gerry B./Mike Davis style.

And Bermy and SkwerI are right, he got the triangle backwards.
 
After listening to Jerry's story about the Coo's Bay cut, I spent many nights thinking about it. Let me present another scenario to you. How many of you have ever tried to fell a hard leaning tree 90 degrees from the angle of the lean? you put a big notch in it about 80 degrees from the lean and then back cut it hoping it follows the notch before breaking out. Sometimes it follows the notch, sometimes it breaks out early and falls to the lean. How many have ever had a barberchair occur in that situation? NEVER!!!

So with that in mind, it makes perfect sense why the Coo's Bay works so well. If you cut out the side wood, it is impossible for the tree to barberchair. This tree was a perfect candidate for a Coo's Bay cut. I have used it on trees but more often used it on heavy limbs and it always works. Forget the undercut, just cut in on both sides to remove half the holding wood without tripping it. Then cut from the back as fast as you can!

Brian, I actually had what you describe happen. Working for Mike over Bergen. Working off a hillside and the tree had a hard lean towards a landslide fence. It was either a maple or ash tree and one of the last of the day. Couldn’t tell it with the lean so tried to send it diagonally across the hillside and the. Lift it out with the crane.

Started the back cut and it got most of the way through and the tree exploded. Luckily the tree had such a significant lean when the barbers chair and the split tree separated it was only going one way and that was away from me.

It was quite impressive and Mike took the piss for a while.
 
for a Coo's Bay cut. I have used it on trees View attachment 134445View attachment 134446His sketch and dent’s
I still see how this would be more prone to chair than a coos

That looks backwards to me.

If I just want a treee down without risk and there is nothing in the fall line. Why bother with a face?

Take the above diagram and reverse the cuts so the point of the triangle is facing the direction of lean. Dont bother with face cuts just make sure the two diagonal cuts meet.

Then back cut with a fast cutting chain and keep going and it will pop off, no drama.
 
i too spent much time trying to decode those Dent Drawings,
joining with the text trying to extrude the gold.
>>put that lil'book down many times as it beat me so bad,
>>but it disturbed my sleep and called me back months later; over and over..
Eventually(after embarrassingly long time.. )
>> it seemed like common sense, saw Mr. Dent's models in more things...
>>even taking the model upstairs to limbs>> was all the same once caught the concept(s)
Mr. Dent totally changed/focused my game and confidence.
.
For urging more towards horizontal sweeps in tree:
>>Tapered hinge where down is the side pull and more across as faced target
>>but not going for 90 across flat horiz, offering relief as goes that branch can hungrily chase
>>45 degrees gives 'squared forces' of cos=sine expressed
>>equal downward stress to sidewards stress in hinge of same wood..
Bargain with limb, use it's downward force to extrude some sideward
>>ain't gonna beat it many times, it has to want to follow path
>>keep slow as not to invoke speed multiplier SQUARED
>>keep steady w/o stalls as no impact
Rope Rescue mantra: slow can be steady, steady can be fast
>>is another version of old careful turtle outpacing young jumpity rabbit.
>>lean and clean progress w/o surprises can bring safely home.
.
To this real fave the triangle hinge/ i always called tapered hinge;
i find the 2 extreme dimensions of: face and 90degrees from.
>>length of greatest leverage support across face that leaves minimal leverage against fold axis
>>cross axis of referenced path dimension, and it's non of totally not in that dimension
Round whole tree as 'hinge' gives equilateral leverage all around,
>>our strip/rectangle hinge does not, plays favorites
>>it favors to yield on the fold axis and greatest leverage against side dis-track-tions
>>Tapered Hinge avails giving imbalance of that greater leverage
>>against greater side pulls
Re-apportioning the same forward resistance, to at same time have greater side resistance
>>but specialized to only the side lean side
>>by in trade not 'protecting' the opposite side of side lean with by the re-apportionment
.
Fat tapered side of hinge as ballast against the cross axis/side pull force
>>to neutralize or filter out the side pull quantity
>>to then only reveal the forward pull remaining quantity(in simpler forward-ish lean scenario)
>>an off balance side pull ballasted out by the off balance of hinge fiber to opposing side
.
Off-side(Dent term) pull imbalance to side met with countering that pull in hinge.
>>Dutch step does this to same side as pull, invokes velocity
>> e=mc2 shows that the static Mass is a smaller multiplier than the speed SQUARED;
AND gives pivotal change, as any hard close, but in step to 1/more loaded side.
Dutchman can capitalize from speed, but is only a tax against tension.
.
As fall starts we have the most compressed pivot position between load CoG and tension support
>>everything else is much less, mostly only distance multipliers for CoG and tensions
The close takes leverage from the CoG side and gifts to the tension hold side
>>at the same time, for greatest effect with greatest impact
>>done to one side can be corrective against side lean.
Stepped/tiered faces operate the compression sides independently in front of hinge
>>just as the Tapered Hinge does in rear of hinge
>>so both can help against side lean.
.
i have gotten fair 90 from hard forward in what i think of as Swing Dutchman(terms vary)
>>whereby usually maintain a patch of anti spin on side compression side
>>but not now>>want spin>> remove anti spin patch on lean side, leaving shorter triangle
>>slam hard confident into the facing for more of that speed squared response back
>>as rubber ball against wall>>greater input speed gives greater response back
.
i look at serving into direction of CoG as lending to it's greatest pull direction
>>for greatest ground concussion as a variable 'spice'
>>then any to the side is less of that spice sprinkled in.
So felling some to side practices technique, and saves ground concussion
>> Doc Shigo showed a hard rain could pummel the magic microbes in the sea of soil.
>>would think heavy equipments and impacts as much worserer.
.
All this supposes a single faultless monolith/not interior fault lines existing nor created in spar
>>i think of BC as a binding against the forward motion that itself will not yield
>>giving split decision of "should i stay or should i go"(appropriately done by 'The Clash')
>>as internal structure of spar is compromised and have 2 moving 'plates' that can bind against each other
>>not be a single moving 'monolith' of 1 concern; but now multiple perhaps combatting parts.
And the massive forces of like 2 bad azzes that never been beat internally overcomes the constitution of the spar to BC
>>especially screams evident to me in pix with the rear portion pitching toward horizontal
>>as forward tree portion stands more tall
>>giving as a classic, olds-cool leaned back ready fer shave BC "T" i think
 
I actually do pretty well with the Dent drawings. There's a couple of the more elaborate cuts that I have to study hard, but generally, I /get it/. I guess ease of interpretation depends on how your brain's wired.
 
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