cutter injury

[chainsawworld]

attached are pictures of an accident i looked into involving a newer cutter.
the first picture shows that a small knotch was taken out of a larger ash tree with a great deal of lean. the back cut was started and the knotch filled causing the tree to slab out.
the second picture shows the height of the run. i shot a tangent and came up with approximately 32 of run. this would put the butt of the tree roughly 60 feet in the air. the feller stood next to the fell and watched instead of taking a safe distance. the tree broke off the run and came down on top of the feller.
the third picture shows the tree next to the stump. it is difficult to see the degree of impact in the photo. during the rescue the fire department remove the top from an other tree that was at the base of this tree. working in the top of the other tree would have made retreat even more difficult.

 

[chainsawworld]

2

 

[StIhL MaGnUm]

Marty,

I have two questions

1.Why did'nt the faller bore/plunge cut this tree,and use a larger face cut?

2.Is the faller ok?

That is the nastiest barber chair I have ever seen.


Later Rob..

 

[chainsawworld]

3

 

[chainsawworld]

rob,
real good questions. first the feller was new and un-trained. open-face bore-cut was the way to take this one down.
clear your escape path at a 45 degree angle away from the lean for at least 40 feet. as you begin your retreat set the brake, turn off the ignition and lift one ear muff.
this incident took place in feb. 2002. the cutter is still doing rehab. from it.


THIS IS A BREIF NARRITIVE AND NOT INSTRUCTION!
chainsaw operators should recieve hands on training from an instructor.

p.s. rob, is there any way you can put your reply behind my 3rd photo? thanks; marty

 

[John Paul Sanborn]

Because they post in a time sequance, there is no way to reorder the thread.

I don't think it hurts the thread any.

 

[StIhL MaGnUm]

Sorry if I messed up your thread Marty I did'nt mean too.

Yes you are correct definetly a open face-bore cut to take down a leaner like that..

Later Rob.

 

[chainsawworld]

rob,
you didnt mess it up. its fine. i hope something can be learned from this thread. marty

 

[koyaanisqatsi]

I'm somewhat new at tree felling. In fact, I've never felled one and won't fell any but the smallest until I get some training and have a very good idea what I'm doing.

Can somone explain in layman's terms what happened to this poor guy and how it happened ?. What caused the first notch to fill? Or was it the second cut that filled? What does "slab out" mean? You may save me from a similar or worse fate.

To me, it looks like a much wider angle for the directional cut should have been used. Then the felling cut should have been OK, barring splitting or splintering of the tree--a good possiblility since it was it was probably under some tension due to the extreme lean. In any event run, I'd have run my pre-planned route the instant anything looked wrong--I might stop the chain saw, but I'd leave it. This guy may not have had a chance to escape.

Thanks,
Pete/koyaanisqatsi

 

[Newfie]

Man, that is a sorry-a$$ notch. Why even bother if you're gonna make it that small and sloping upward. Ash loves to slab out on that vertical grain if you do something stupid.

Thanks for the thread Marty. It is too bad that so many people have so little respect for the awesome power of saws and trees. Thoughts and prayers for the injured party. This sounds like the incident that had you quite upset last year.

Pete, ALWAYS use your escape route for every tree. I can't think of any reason to stand at the stump once the tree has been committed to falling. Others please correct me if I might have missed a reason to stay and watch.

 

[John Paul Sanborn]

I think I would have used a much deaper knotch to fell that tree. I've never strapped or chained a fell, but I can see the need now. Even on a small tree like that.

Pete, the face cut never came into play in this. The wood failed axis of the grain and massively barberchaired. Any wood that splits easily can fail like this when improperly felled. even if the hinge worked ti would have probably failed early and jumped back.

 

[Greg]

I've never watched a barber chair happen, I've seen the stumps but that is it, and this one is HUGE!. How quickly does all of this go down? Is it a slow cracking and splitting, or does this happen in the blink of an eye??

 

[murphy4trees]

I'd bet money that this notch was a dutchman on the backside of photo, that is crossing cut(s) on the notch. In the case of crossing cuts, as the tree begins to move, the kerf of the crossover cut closes. When the kerf closes the tree stops moving, effectively preventing the notch from closing. And the force of all that weight pulling the tree foward causes the trunk to split along the grain.. this is called a barber's chair. The rip goes up the trunk to a point where the trunk snaps in two. This becomes a new "hinge point". The tree above the new hinge point falls foward on its way down, while the attached trunk section (below the new hinge) lifts up, opposite to the direction of fall. This lower section lifting to the rear can injure the saw operator as it lifts up or as it falls to the ground from the height of the new "hinge point".
I've seen it happen and it happens fast. All that pressure "pops" the wood along it's grain, like a splitting baseball bat.
God Bless All,
Daniel

 

[koyaanisqatsi]

I think I understand better what happened

I have nothing but sympathy for the cutter and his family. Dangerous business even for the experienced. A simple error in judgement, short distraction, or the unpredictables is all it takes. Yet I'm determined if I can find a company to give me work *on the ground doing support work* first. Mostly smaller urban work for now.

I've thought of using a chain wrapped from near the cut point to a couple or several feet up the tree with a come along or binding lever to tighten the chain. Would that have prevented the accident? It *feels* like it would have, but perhaps not. Many uncertainties.

Thanks,
Pete

 

[murphy4trees]

Pete,
Wrapping a chain to prevent the trunk from splitting is a good added precaution in heavy front leaners, however it is not the answer for you.
The way to prevent barberchairs, in nearly all situations you will face, is to learn how to make a proper open face notch. I do this by making the top cut first at 70* or so and then looking through the kerf of the top cut as the bar is making the bottom cut, so as to avoid crossing the cuts. Also having a sharp chain that cuts straight is highly recommended... If your saw is cutting crooked, take the time to sharpen it before felling.
There are some good videos on open face notchs and back release felling techniques, produced for loggers, available from International Paper.
As far as the above injured party, my guess is that lack of proper training was more at cause than any error in judgment or distraction.
Any time you are felling in the woods, you need to move away from the tree at 45* ASAP. The above videos cover that well too.
It is possible his saw pinched and he was fighting to free it when the tree went... in that case, leave the saw and run for your life!!!!
God bless,
Daniel

 

[lync]

My two cents

I would have to agree with JPS the notch made no difference in this scenario, the hingepoint is way up the trunk!

The hinge does look deep enough 80% of the diameter.
The back cut is a little high. The only thing that would have prevented this (imho) would have been to plung cut and leave an inch thick hinge, then back release it. I would also bet the feller was not cutting at full throttle. If he was cutting fast he might have gotten the hinge to activate before it completely split out.
The hinge would have closed quickly and not guided the tree completely to the ground.

 

[murphy4trees]

I have to respectfully disagree with JPS and Lynch on this call.
After reading lynch's post I went back and looked closely at the first photo, the hinge. If you look closely, check out the trunk on the face side, above and below the hinge... the tree clearly moved...
and then look closely at the apex of the notch.... it's clear to me that the bottom cut on the face bypassed the top (angled) cut. That is why this tree split. The tree moved until that kerf of the bypassing floor cut closed, and then there was nothing for all that force to do but split the trunk.
I've done it and seen it done, enough to recognize it. I guess I shouldn't be too proud of that. And because I now understand the physics of the hinge, I make 100% certain there is no bypass in the notch. To me, that is the lesson we can all learn here. To imply that this can be avoided in the future by chaining the trunk is misleading at best.
God Bless,
Daniel

 

[chainsawworld]

murhpy,
it is hard to see in the photo but fibers inside the knotch were broke and crushed.
the best way to have taken this down was at ground level, open-face bore-cut, flat and level with no by-pass any place, cutting opposite from the lean.
THIS IS JUST A BREIF NARRITIVE AND NOT INSTRUCTION!
marty

 

[koyaanisqatsi]

I guess what's most troubling to me, aside from the cutter's injury, is that felling this tree *looks* like a "piece of cake".

A decent directional notch, a decent felling cut and the tree should simply fall completely in the intended direction.

And it just didn't. The unpredictables again I guess. Have at least one clear escape path and use the best one when *anything* is seen or heard falling seems to be the rule. I assume that if you have only one escape path, that just could be the wrong way to go.

A similar incident happened to me years ago when pouring cement for a 60 feet concrete silo. Broken winch, so the bucket was being pulled via a cable wrapped around the front bumper of a pickup. The guy backed up with a full bucket (maybe 30 gallons). I operated the concrete chute and had to stay under to steady the bucket until it was out of reach. I heard the whoosh but did not see the bucket fall from near the top. I was in the next county when the concrete bucket hit the ground and split. We got a different bucket and resumed. Never forgot that close call.

Pete

 

[Newfie]

His face cut/notch is clearly not up to snuff, not only does it cross at the intersection, but the bottom cut is not level (or sloping down)and slopes up into the intersection of the two cuts, effectively making it even smaller. I think also the back cut that eventually failed was attempt number two at a back cut if you look carefully at pic 1 and 3.

lack of training and no respect for the danger are clearly the culprits here.