Tree Felling Direction Of Falling Question ?

[Robert11]

Hello,

Retired Engineer, and I guess I have thought about the following a bit, and realize I don't understand what happens.

Would like to, so thought I'd post here, and if I appear really dumb, I apologize. Still, asking questions is always the best way to learn.

Have a chainsaw, used mainly for small limbs and brush.
Have never taken down a tree, but was wondering:

Let's say that the tree is assumed for this discussion to be a perfect uniform cylinder.
If so, the weight (vector) then can be considered to go right down the center.
No problem here.

All the how-to felling sites say the front cut, which defines the direction one wants the tree to fall, should be no more than 30 % of the tree diameter deep.

So, the weight vector, being at 50 % of the diameter is then to the rear of this cut.

Then the Back-Cut is made.

Even leaving an inch or two for the "hinge," it seems that the weight vector would still definitely be to the rear of the Hinge.

(it would have to go the 70 % of the diameter forward to meet up with front cut, minus the hinge thickness)

And, thus, the tendency of the tree would be to rotate Backwards, not to the front as desired.
True ? Assume No wedges or ropes to help determine the direction of falling.

This would appear to be true even though there is a large wedge taken out from the front, and just a narrow sawblade width Back-Cut ?

I have no doubt that I am wrong, but what am I missing, please in thinking about this ?

I've looked at a zillion videos and on-line diagrams, but none seem to explain this at all.

Is it that the tree cuts are ALWAYS made to have the tree fall in the direction of its normal leaning ?

And if a different fall direction is required, then one uses wedges, ropes, or some of those other "fancy and technical" cutting techniques ?

Thanks,
Bob

 

[twochains]

Sounds like you have the theory, now it is time to try it out. Is this a trick post?? If not...there are tons of Pros on this site that will help you out. Cheers!

 

[northmanlogging]

In a physics sense you nailed it, however its a rare day that you will come across a perfect cylinder of a tree, limb weight, lean, wind, all have an effect on where the tree wants to go.

Face cuts of 30% are really more of a guide line. A little more or less all depends on what the tree is telling you and how good you are at matching up your cuts... But 30% is a good starting point.

Wedges and ropes are tools in the faller's tool box (I.E. pockets) much like any of the fancy siswheel, dutchmen, block, humboldt, saginaw, conventional, swedish fish dance... They are all just things to help get the tree on the ground where you want it to land. Wedges help overcome that bit of back lean or the "perfect tree" and gives it a little lift off the stump, thereby tipping the balance in the desired direction.

Some folk will make the claim of not using wedges, different timber different situation, me I carry wedges and use them a lot.

 

[twochains]

In a physics sense you nailed it, however its a rare day that you will come across a perfect cylinder of a tree, limb weight, lean, wind, all have an effect on where the tree wants to go.

Face cuts of 30% are really more of a guide line. A little more or less all depends on what the tree is telling you and how good you are at matching up your cuts... But 30% is a good starting point.

Wedges and ropes are tools in the faller's tool box (I.E. pockets) much like any of the fancy siswheel, dutchmen, block, humboldt, saginaw, conventional, swedish fish dance... They are all just things to help get the tree on the ground where you want it to land. Wedges help overcome that bit of back lean or the "perfect tree" and gives it a little lift off the stump, thereby tipping the balance in the desired direction.

Some folk will make the claim of not using wedges, different timber different situation, me I carry wedges and use them a lot.

Very well answered northman!

(hey did you get my pm?)

 

[056kid]

Throw the engineering stuff out the window. Every tree is different. I cant tell you how many times I have sawed up what I was sure was a heavy back leaner just to watch my axe handle drop fast as I was finishing up the back. That's what makes it fun and interesting thouugh.

 

[HuskStihl]

If you fall a telephone pole on level ground with no wind with a 30% face, about 60% of the way thru the back cut the tree will follow gravity, sit back on your bar and probably just stand there, just as you figured. A wedge would keep the back cut open and make it follow the face. The pro-fallers probably have little experience with this, but I practically have a Ph.D. in pinched bars:biggrin:

 

[roberte]

well i dont know if i would throw all the engineering stuff out the window. a lot of phyisics are involved and wedges are a good thing. i know i dont know it all but its taken a lot of trial & error in 34 years of saws to get to this point.
just my opinion, but sometimes the smaller trees are more of a pita than some of the bigger ones

 

[bitzer]

What you are explaining is a stob or a straight stem with no top. Its tough to get them to tip because there is nothing (like the top) prompting them to move. I had a willow stob that was 6 ft on the stump last summer. I had it sawed up all the way with the hinge at the 50-60% mark. It just sat there so I gave it a little push with my hand and it wiggled. A good push and it was over. I was alone, but couldn't help but laugh. That's kind of what you are talking about, but like 056 Kid said that situation rarely exists in the world. I personally think of a tree in terms of physics being involved or at least did when I got started. Now its kind of second nature. You saw a deeper face if you need to or wedge or swing it or whatever. It all depends on what the tree gives you and what you want to do with it. Learning how to really use the tree and then saving it out is the challenge. Anyone can dump them. Experience. Give it a try. Something small. Play around.

 

[DavdH]

It's all physics, vectors, just interpreting all the forces takes a super computer with some interpolation of parameters (fallers judgement usually from lots of experience). I've cut tall vertical timber and sometimes it is sky bound, some outside force gets things moving be it wind or a wedge. All the face, hinge, back cut are control forces, gravity is the only constant. Now go tell a 70 year old faller he knows physics and vectors and you get replies like some of above, it is an engineers dream, and that is just getting them down, get into the yarding especially cable systems and a good engineering back ground can save your butt. Bucking is the same and it is learning the forces and interpreting them before ya get hurt or pinched.

 

[Oldtimer]

Gravity works, but wind is a shifty character.

 

[roberte]

Gravity works, but wind is a shifty character.

Ahh yes, the two great equalizers

 

[treeslayer2003]

....and remember its not the wood that was cut but the wood that was left that helps determine direction of fall .....if done properly

 

[RandyMac]

....and remember its not the wood that was cut but the wood that was left that helps determine direction of fall .....if done properly

explain in detail.
Personally, I think that statement is baloney.
The hinge helps, the face cut does the work.

 

[Woody912]

as others have said, if you have cut a stem with the top completely gone and it is a straight tree, they just want to sit there just as you postulate. I used to think wedges were cheatin', now they're my best friend and life guard. If you get really bored, look up the OSHA specs for moving a backleaner with wedges. Can't believe OSHA does anything useful

 

[treeslayer2003]

explain in detail.
Personally, I think that statement is baloney.
The hinge helps, the face cut does the work.

don't wanna argu with you randy, but when attemping to swing a tree one way or the other , if you cut one side of hinge and leave the other wich way will tree normally want to go? always follows holding wood right? oh and only trying to give someone who is not a timber faller a different way of thinking about it ........please don't light me on fire

 

[HuskStihl]

....and remember its not the wood that was cut but the wood that was left that helps determine direction of fall .....if done properly

explain in detail.
Personally, I think that statement is baloney.
The hinge helps, the face cut does the work.

What I always say is "the wood you don't cut is what's left after the wood that you cut has been cut.":biggrin:

 

[Metals406]

don't wanna argu with you randy, but when attemping to swing a tree one way or the other , if you cut one side of hinge and leave the other wich way will tree normally want to go? always follows holding wood right? oh and only trying to give someone who is not a timber faller a different way of thinking about it ........please don't light me on fire

So you've met Randy. :hmm3grin2orange::hmm3grin2orange:

 

[twochains]

:hmm3grin2orange:

 

[slowp]

A faller does have to directionally fall the trees. That means that they have to gun them in a certain direction/pattern/lay to make yarding efficient. There will always be a hard leaner, or just a bad tree that won't behave and will mess things up a bit, but not very many....we hope.

 

[Gologit]

A faller does have to directionally fall the trees. That means that they have to gun them in a certain direction/pattern/lay to make yarding efficient. There will always be a hard leaner, or just a bad tree that won't behave and will mess things up a bit, but not very many....we hope.

I like your faller emoticon.

We need one for the Forester too. How 'bout :msp_confused: Or maybe :bang:


Anybody else got any ideas?