Proper wedge technique?

[edge]

When using a wedge on a larger tree to prevent the tree from "sitting back" on the bar as the back-cut is made, what is the proper technique?  Assume your bar length is right about equal to the diameter of the tree.

I know this sounds like a silly question, but seriously, what do most of you do?  

Begin back-cut, remove saw.  Set saw on ground.  Insert wedge.  Resume with back-cut, but how to insert saw into back-cut kerf evenly/easily again?  

(1)  Tip first into the kerf with danger of grabbing or kickback...depending on space in kerf might not be easy?  

(2)  Or insert saw into back-cut starting near the bucking spikes, working the tip back through...while keeping the tip short of the wedge you inserted on the far side, although that might be difficult?

Thoughts, ideas, opinions?  I'm curious as to what is the best/safest way, I'm sure there are other techniques that people have used.

[Larry]

I saw out my hinge first and bore right behind the hinge.  Cut to the back of the tree and leave a little holding strap.  Pull the saw out, put in my wedges, and cut the back strap.  On a fairly well balanced tree you will never pinch the bar.  On a tree with heavy side lean I will stop sawing the back cut about half way through and stick in a wedge or two but I don't pull the saw out.  Real heavy back lean I swivel the saw so my holding strap is a little off to the side and put the wedge in closer to the back of the tree.  Hope I explained it right.  Be a whole lot easier to show ya.   Just another advantage to the bore cutting.

[Kevin]

I usually start the back cut, insert the wedges then continue with the back cut just in front of the wedges.
As the back cut progresses you can tap the  wedges ahead behind the bar.

[rebocardo]

How I do it.

For a decent size tree, say 16+ inches, while doing the back cut, stop, and put two small 5" wedges in from each side of the tree so they are parallel with the bar.

Start cutting and once the saw is in deep enough start inserting 1 or 2 longer wedges down the middle between the two outer wedges so they are at 90 degrees to the notch.

Once the tree starts lifting and the two smaller wedges are loose, inset bigger wedges at 90 degrees to the notch on the sides.

For the small side wedges, try to get ones that have little dimples so they do not spit out as easily.

Once I start wedging, unless I am cutting the tree from both sides I try not to lean around the tree or have my head directly behind the tree.

So, when driving the wedges, I tap them in with a hand, then use a longer handled sledge to drive them in. The reason being is if the tree splits or barberchairs, I want to be at least three feet away from the trunk with a good running start if I hear a crack or see movement.

I do not take my saw out until I think the tree is about to go and I am finished cutting. I try not to tip the tree much at all until I have finished my cutting. Sometimes I will insert side wedges to keep it stable without lifting it.

Once my saw is out of the way, I get my four foot handle sledge and drive the wedges in gradually until I hear a crack, then I exit and watch gravity do the rest. Sometimes it takes a few minutes, but, if the tree is wedged well, once you have it tipped and hear a crack it will come down.  

If I plan on using my truck to help guide the tree or bring it down, this is the time I get in the truck or start the winch for gentle persuasion.

[BC_coops]

When tapping in wedges on a tree that you are nervous about splitting during a cut, has anyone thought of wrapping a chain choker around the trunk, to "bind it up"?

I was thinking along a line like this ... start with enough 5/16 schedule 70 chain choker (e.g. for a 3 ft tree, say 20 feet of chain with a grab hook on one end), and wrap the chain around the tree *twice or thrice or more (but never just once).  After the tree has been notched, begin wrapping at about 5 feet above your planned backcut.  Set the grab hook (and dangling end of an unused length of chain) so that it will be positioned right over the notch cut.  The two or more loops of chain can then be "worked" down onto the trunk (each loop can be pulled down to its own natural level).  At this point, the choker will be binding the trunk together.  Then, if a slab tries to peel out, you will have a few micro seconds of additional time to react and get the H... out of there.  The movement of the breakout slab should be limited to a few inches, as chain links will sink into the bark and hold hard.  (I hardly ever drop a tree now without about 40 feet chain and 50 feet of 3/8 wire rope on a hydraulic winch -- I mounted a 12,000 Mile Marker on my front bumper.  Awesome!!!  Once you have used a winch to control a fall in tight conditions, it takes 20 minutes to setup, and you will never again look back.   Also great for releasing tension and general tree control once its down, during limbing ... )

BTW, apparently slabs do not always spring out in a "predictable way" as is more or less implied by the picture books on saw use.  They can come out sideways too, and apparently they can come out with plenty of twist and spin in them.  Moreover, the tension which sets up the slab might not be on the backside of "the geometric lean," because of windage, or even because one side of a tree is in a sunny-dry environment due to recent clearing, the other is in its old dark-wet one, or whatever.  Wm Hazel Construction in NoVA lost an operator 2 years ago, when a slab popped out sideways on an leaning oak, knocked him down and ... and then ... decapitated him.  Decapitated, guys, as in detached head, as in when the rescue crews had to pick up the pieces, they decided to put his head into its own separate storage bag.  Nor was he an inexperienced operator, as he had an associate degree in practical forestry from a good school in North Carolina.  (That is what prompted me to consider the use of a trunk choker when touching a saw to a leaning, oaks etc.)  It's my humble opinion that today's one-speed saws contributed to this particular fatality, as it does to every accident when an operator gets into a kind of mental "groove" (the only way I can describe it ... a kind of "feel-good trance" which happens from having no option but to hold the throttle wide open ... operators become too focused on keeping the saw running in its narrow high-end power peak, when circumstances might require backing off the throttle and listening to ... the tree, which is the thing that really wants to kill you.  Unfortunately, when you back down with these newer saws, the torque rapidly drops, to effectively nil, then the chain seizes in the backcut, then the clutch starts smoking as you try to giggle the saw and get it going again, while the saw it "bitches'" at you with phoots, pops and rattles for shifting focus to the tree.  Thus the need for a choker to wrap up the tree ...

[beenthere]

BC_coops
I sure haven't had the kind of tree-cuttin experience you have had. I can see and hear what the tree is doing as I run my saw at high rpm (its cuttin and not jumpin and sputterin at that speed), even with ear protection.

Years ago an old neighbor farmer showed me the chain-wrap technique you talk about and I used it until I learned the plunge cutting technique for leaner trees, and I use it a lot now. Don't spend the time to do the chain wrap, but wouldn't poo poo it either for someone that wants to use it.

For trees that are in the 20" diam range at cutting height, I usually place a wedge in the back-cut as soon as I can get it in there without touching the chain (I don't remove the bar and tap the wedge in with a 'club' made from a short white oak stick laying around). That wedge keeps the tree from setting back down on the back-cut in case I haven't figured the lean correctly (it happens sometimes). As I approach the finishing of the hinge, I may tap the wedge again if it shows some looseness. If tight, I get a couple more wedges to add to the 'lifting' of that side of the tree before finishing the hinge. I also take that time to inspect my back-cut to see that it is in the right place and going parallel to the notch cut. That tells me what to expect when I continue cutting to finish the hinge.
This technique has worked very well for me for 35+ years in hardwood stands (knock on wood).  

[BC_coops]

Hi beenthere ...

I been getting increasingly jumpy about pushing the top of bar into anything strange lately, ever since I banged into a buried nail cutting a small limb wide open a few years ago.  I was using an old Homelite Super EZ AO (basically 40cc of numbing vibration on a 3/8 chain).  You cannot imagine the speed and power of the reactive forces involved ... without any notice the saw blew out of the cut like a bullet comes out of a barrel.  It just about yanked my arms out of the shoulder sockets, as the saw twisted up and went wizzing past my legs.  It landed about 6 feet away ... snapping the bar tensioning screw and lug, but not bending the crank, and leaving me in a daze.  Thank God I was not standing in line the forces, picture book style, as I have little doubt that the forces and acceleration that happens when a pushcut slams into a nail would crush a pelvic bone to beyond recognition.  I recon the nail was probably put there by a hunter for a tree stand.

[Tom]

Welcome, Coops.

Just because someone cruises the woods doesn't mean that they won't drive a nail in a tree, does it?

I hear the bragging of deer hunters all the time of the stand they built with the comforts of home.  I tell them that I wished they had stayed at home because they just ruined somebody's tree and cost somebody else a lot of money or harm.

They won't put just one nail in there if six will work, either.

Situations like that are wake-up calls and remind us to use both hands and hold the saw firmly.  Even the little saws will get you.

[tony_marks]

  shh,,dont give these dang enviromaniacs,no ideas.. i can see it now.. well gang split up and after every tree is properly nailed .
 we ll meet on the back side.. then well go confiscate that dairy farmers cows that have hip bones showing..[a dairy cow that is meated up like an beef .. probably aint much of a milk cow].
  if i stepped on some toes.. so be it..

[beenthere]

BC_coops  Welcome to the forum.
I have a very good friend who is 'jumpy' (very tentative) when cutting a tree and using his chain saw. I get real nervous watching him, as he lets his saw slow to almost an idle as he picks and pokes at the wood he wants to cut. When doing that the chain grabs easily and the bar is jumping all over the place, and kicking back. Now I don't know how you do it, but from your descriptions it reminds me of my friend (hope you take that in a kind and caring way   ).
My experience is that the saw bar does very little jumping and kicking back when the rpm's are up (wide open or near wo).  Maybe I am all wet with this 'experience' and cruisin' for a bruisin'.  But to me, a slow moving chain is a dangerous chain. It will grab. A fast moving chain will cut (unless pinched between wood being cut on the bottom side of the bar and the top side gets jammed under another log or limb). Even nails with a fast chain, will either take out the nail and/or take out the teeth - so fast that the bar doesn't have time to lurch because the teeth don't get a good bite. (to me its akin to pulling the starter rope too slow, and getting it ripped out of your hand or fingers).
I don't advocate being reckless and being a 'bull' when cutting but I don't think being tentative is safe either.

[edge]

Hey beenthere, you said:

"For trees that are in the 20" diam range at cutting height, I usually place a wedge in the back-cut as soon as I can get it in there without touching the chain (I don't remove the bar and tap the wedge in with a 'club' made from a short white oak stick laying around). That wedge keeps the tree from setting back down on the back-cut in case I haven't figured the lean correctly (it happens sometimes). "

Since you don't remove the saw from the back-cut when inserting the wedge, do you release the trigger on the saw to stop the chain, then hold the saw one-handed while inserting the wedge with the other?  Do you experience any grabbing in the kerf when resuming to apply throttle?  Just curious on this...I think it would work fine as long as I'm extremely careful not to slip and hit the throttle trigger while inserting the wedge.

Thanks for all the input so far.

[beenthere]

No, don't have a problem (I don't insert a wedge while saw is running, as I don't one-hand chain saw-and the saw will stay un-attended in the cut while inserting the wedge). I know these things (hit the trigger, etc.) are possible (one could set the brake), but are the same if you remove the saw, and more dangerous than leaving the bar in the cut, in my opinion. Others may feel more comfortable removing the bar. If I remove the bar, or re-insert the bar, it is without the chain running, unless I've let the saw-cut choke (fill)-up with with sawdust.  
No specific hard-fast formula or procedure, as circumstances often vary by tree. Just need to be thinking always about the moment, and what could, can, or might happen, and with experience, one will be pretty sure most of the time what will happen. Good luck.
I sawed down a lot of trees before I had someone 'educate' me a fair bit about the right way. I listened and applied what I learned. Much better results after that.
I will admit to getting careless at times, and forgetting to do some things in the right order. Trouble happens then.  : :-[

[rebocardo]

I never remove the bar in a cut without wedges being in there, if the tree sits back your bar may be the only thing that holds the tree up.

I have been tempted to use chains to bind a tree, but, it would be before I started a notch. I have some reservations about standing in front of a tree I have already weaken with a notch along tha path I want it to fall.

Is 5/16 really strong enough to hold a barberchair together? 3/8 is only good for about 3500 pounds. Someone posted a few months ago about the 3/8 chain poppping about like a grenade.

Do they teach these things in the GOL classes?  Anyone have experience or proof where the chain actually worked?

[TreeSpyder]

i've bound some that might split with 2" yellow webbing and ratchet (cargo/trucker straps?).  Ratchet on rear corner of fall.

The deeper the hinge comes in, the more tree pulls towards target, but the less leverage the wedge gives, for it's distance from the pivot of the hinge is shortened.

No dutching, crossed cuts in face to give no impedance to the forward motion by mechanically not giving stop/step command to system.  Making felling and wedging lots easier and safer.

i think barber chair is caused by the immense weight, speed and levearge of tree trying to charge forward, all that force funneled down to hinge.  And the total relief of the face and speed, direction of the backcut are not good/quick enough to give relief to all the sudden tree force,and hinge area tries to fight tree force.  So, instead of going forward with the tree force the hinge and face fights, the back and top of tree go forward, while front lower part of tree (directly over face) matches pushing back.  The spar at some point can't accomodate both forces, and gives split decision.

i think no face can give this non-relief, as no relief is given by face, like not taking a wheel chock out before rolling forward; the no face pushes back.   Similarily, dutchmans, crossed facecuts can give resistance to the immense tree force charging forward, and possibly invite barberchairing.  i think that if the backcut isn't smooth and qucik enough in some cases (larger), to give proper releif the forces can stack against ya again!  Especially if there is some kind of impedance, dutching, crossed face cuts (places hinge inside of hinge that closes immediately and pushes back against tree moving forward), and tree isn't moving fast enough (speed set by back cut), to throw through the stop/impedance in face.

i wedge forward to target.  Saw in tree.  Hinge fat on side controlling against side lean.  In good wood allowing the hinge to carry sidelean, wedging to target, not to correct sidelean.

Or something like that,

[Kevin]

Hello Ken, welcome to the Forestry Forum.

[BC_coops]

rebocardo - 5/16 grade 70 chain (gold transport chain-generally available at truck stops and generally not available at hardware stores) is rated at 4700 working - which is rated, if I'm not mistaken, with a safety factor 10 for failure, for lift hoists.  The chain will probably begin to deform at around half failure (say 10T).  The nice thing about chain is that when it goes, the rest of the chain will just drop straight down.  There is no resiliancy in the deformation of links, and they do not store and return energy (unlike wire rope!, which will sling back)  That's what nice about chain.)  The idea of two wraps around the bark (twice the strength) is that it's almost impossible to get one wrap tight to the bark, because the slip hook gives back its hook length.  With two wraps, a 1" notch will help hold the upper wrap in place, and then the lower wrap can be "pulled down" onto the tree, to tighten up the whole system.  The the 5/16 grade 70 weighs about 1 lb/ft, which may not seem like much, but it kind of funny to work with.  I suggest 5/16 chain, because I know it works.  I use a lot of it with a 12,000#  hydraulic winch on my front bumper (google on "Mile Marker Winch") to dynamically pull trees into a precision controlled drop zone, and to roll over the large ones during limbing.  Couldn't imagine life without it.  Funny, but it's the $300 in chains which makes the $800 winch usable -- I've loaded all my 5/16 g70 chains several times at winch stall, e.g. +/- 6T or roughly 3x their rated hoist load (the front-bumper & winch is tied to a stump under the truck or behind it) and none of the links have shown the first sign of deformation (unlike the wire rope in the winch, which does deform with use and has to be replaced.)  3/8 chain is too heavy for me (20 ft weights 30 lbs, and any link you grasp to hold the chain against the tree also weighs 30 lbs.)

TreeSpyder--that's a nice idea the cargo straps - the only thing is that I'd be careful because, unlike chains, as the straps are stretched, they store beaucoup energy (a lot of it).  With no energy stored, chains just drop on failure of a link.  But when a strap fails, the stored energy could have that strap and ratchet slinging out at deadly velocity ... there are stories of trucks cut in half by the energy stored in the "small" e.g. few inches, stretch of web slings etc.  Chains just make a loud noise and drop.

a subdivision developer recently (two years ago) lost an employee to a barberchain (he was fully decapitated, as in rescue workers decided to take his head back to the hospital in a separate bag).  So, that gets me to thinking, if wrapping a tree might give me evey one footstep of advantage, then it might well be worth considering.

[TreeSpyder]

Hey Kev;

Guess i been busted already!-

i use the cargo straps cuz that is what is around, light, cheap, easier to fold tail out of the way of cut when bracing spar over face etc. and sometimes (especially after Florida Hurricanes) use them 'in tree' for fortification of a split to cut, rig off of, or perhaps climb above.  The compression on a crack/weakness is so fortifying, if bracing from ground, will place sling in proximity of crack to fortify as brace is tightened, giving binding and support with the same pull.  The inability to shift, makes the crack fortified.

Good point on stored energy/recoil!  Would that go more with linear rather than circular loading?  Somehow i have had the imagery of worse case scenario of 'explosion' inside of circumfrence throwing metal outward?

i think a barber chair comes from the relief of the FaceCut + BackCut etc. is not enough in power, speed, and direction for the forces lunging forward.   At some point the internal fight of the escalating forces forward and the non releif placing matching backward pressure cumulatively is greater than the structral strength of the spar.  The house divides allowing the split decision of not totally forward or back, when it can't stand the level of internal forces to opposite directions.

Or something like that,
-KC

[BC_coops]

tree spyder -- your explanation of barber chain (does that name stick because in addition to tilting back, a barber chair can also spin around on you ?) is the best I have seen -- in any case it's the first time I've encountered the idea that it is the shifting of energy of the fall, from one hinge point to another (as in a poorly cut notch) --.that once the tree starts going, it's important that the hinge be clean, so that the energy is focused along a single edge.  When that all of that energy has to suddenly shift to another point, either forward or backward, an internal torque is setup, and baam!  Now, it makes sense.  I've wondered for years about the mechanics of it ... thanks,

You are also right about the circular stress v. linear stress.  As usual, I started to think about it after I sent my post, and I still don't feel like I've got thru it yet.  In any case, my idea that if the chain failed, it would just drop, as it would in a linear pull, has to be recanted -- It's totally wet -- because if the chain popped, the tree would likely split too, and as the back end of the tree exploded upward (or sideways), the two ends of the chain would come "unwrapped," probably very violently.  That would also be the case for failure of a cargo strap.

I happen to have chains handy since I regularly use a hydraulic winch, which I attached onto my front bumper.  Them chains are heavy, and slingin' 'em around anything will definitely tighten you up, and tire you out, esp your arms, and shoulders.  So the lighter weight and easier placement of the cargo straps would make them worth every penny.

[TreeSpyder]

i think that a poorly crafted face that has crossed cuts (especially bottom) provides early compression/pushback against the tree coming forward.  The tree coming forward, does so with all of it's weight X it's leveraged length X it's speed, all pulling on little hinge flap and face pushes.  The mechanchs has to be clean at those forces.  "Accidents happen, cuz Physics doesn't take any holidays" (don't know where i stole that from!)

This large, multiplied out force, recieving a responding/ matching push back as a small kerf of the crossed cuts closes; would be equally as awesome.  The 'internal face' of the crossed cuts, becomes the main operative/ 'machine command'; over ruling mostly the tendencies of the outer/intended face.

This could include siezing, barber chairing etc.  Being that a kerf/ crossed cuts act as a face immediately closing, the spar can't gather enough force to throw thru the step in face, giving siezing, or matched forces, giving barber chair of split decision that superceds the bounds of the integrity of the spar.

We take Face Cuts as to remove the chock from a tire, to allow force to roll forward and not get resistance, not 'barberchair' etc. from 'back pressure' of wood in face.   This takes support away from the pushes, and gives it (for the time being) all to the pulls in the hinge/backcut style. When the hinge closes , the hinge pulls unload as the face compression takes over support.  Usually tree force can throw thru that position and rip free, after having a 45 degree head start run.  Crossing the cuts, places this resistance back in immediately on movement, negating lots of reason for making face!  Taking a lot of control away from the hinge pulls, as compression supports from closed kerf.  But spar has no running start to throw cleanly thru the early closing face of the kerf(for kerf closes so quickly), a variety of probelms can begin.  Including needing more wedge or line pull that on a clean face would not be needed, some loss of direction, risk etc.

'In Tree' on medium stuff etc. using the push in the face on heavy side to steer to the still pulling target side (instead of both sides of face either pulling or pushing agianst each other, get them to push and pull together); gives lots more strategy options!  Done by dividing face into left/right, seperate machine commands by the facecuts.

 :PSorry, i get going sometimes!

[redpowerd]

that being said, is there any way to safely test this theory by introducing a force to barberchair a tree, i guess to see exactly the cause and when exactly it happens. ive only chaired one tree and it was under 12", i dont remember why or how it happend, i think because it was so small i tried to jump the stump.

i wish i could understand your explanation better.

[redpowerd]

oh and welcome to the forum spyder, another knowledgeable member, stay awhile!

[Kevin]

This being a straight, well balanced tree...


If the hinge is too far forward the tree becomes difficult to lift due to all the weight behind the fulcrum.

As the hinge gets closer to the back of the tree the tree will lift better because there's less weight to lift over the fulcrum which is the hinge.

If it gets too far back the tree will want to fall on it's own with very little if any wedging but this develops less control in felling the tree.

[Jim_Rogers]

Kevin:
Are you saying that position 3 is better for felling then position 1? (in your drawing).

Jim Rogers

[Kevin]

Not the best Jim.
The best is placing the hinge at 1/3 of the tree dia. or at least between 1/3 and 1/2 the trees dia. but not past 1/2 for normal felling.
The third illustration shows where very little or no wedging at all would be required but the loss of control because of the added weight ahead of the hinge combined with a smaller hinge would make it less desirable and leading towards dangerous.

[TreeSpyder]

Kev's diagram is great!  i look at the more rear placed hinges, as less for the wedge to lift, for there is more wieght on the other side of the pivot/hinge, helping to pull as the wedge lifts.  But, that also takes leverage away from the wedge, by virtue of shorter distance from wedge's lift to the pivot/hinge.  Stopping FaceCut some before 1/2 way, places hinge at 1/2 way, widest part of round.  This gives more sidelean control leavearge.  Also a thinner strip of wood (hinge more spread out long across than deep) to flex forward easier.  i think the  less initial pressure forward from shallow face, forces weaker hinge in matching response.  

i think the the pressure at first folding (that doesn't stall) sets the maximum hinge strength; as an equal and opposite force, just barely upset (hinge can't hold after so much backcut).  

Thanx Redpowerd.  i'll be glad to explain any part of felling model you'd like, am trying to get right words for putting on my sight : http://www.mytreelessons.com/Supporting%20Wood.htm is a page in some raggedy progress to this end.