can someone explain to me how to do a 3 stage backcut?

[Zackman1801]

Hey all, just a quick question to ask to the pros out there, here it goes.
Im in high school and Lately we have with our forestry class been cutting in pine and some scattered hardwoods that cannot be cut with a single stage bored in back cut, and an open faced notch. Some of the guys have had bore in from both sides of the tree (double stage backcut) to get it to come down but they have told me that there are trees around even larger than that that may require a triple stage back cut. although i dont know how to do a triple stage back cut. I do know how to do a double stage. The problem that is causing this is the short bars we use, 16". I will if need be ask one of my teachers show me the cut but it takes time waiting for him to clear out a time when he can move to our harvest team to show us. and while hes freeing up time for us (since there are 3 or 4 going at 1 time plus he has to monitor the skidder and other forman) we end up sitting around and wasting time, which you all know is a no go.

thanks zack

 

[smokechase II]

Three stage

I've never heard it referred to as 3 stage but that makes perfect sense.

Face cut is complete, then:
1) Do a bore in from the face, cutting out the center of the tree, at the same height as the other back-cuts will be.
2) Complete the other back-cut(s) as appropriate.

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Usually, be sure to not cut off the holding wood at the corners. Corners are the outsides of the hinge, both sides. That is the most important wood for control. (exception; barber chair risk in some instances may require holding wood nipping at the corners.)

Your face center bore should be just enough plus an inch or two more for a guaranteed overlap with the other back cuts.
The further off the back-cuts are from each other horizontally the more resistance they have to popping and letting the tree go.
This is more of a problem with larger diameters.

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You may wish to have another person guide your boring cuts to assure a closer match.
If another bar or straight stick is available put it in the face center bore slot and that will help your partner help you.

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The bore cut shown here is with a humboldt face and for reducing barber chair risk. This method may be more important than a boring back cut for that threat.

So just because you have a longer bar doesn't mean you shouldn't get good at the face center bore.

All the best.

 

[clearance]

Maybe this means sawing out the center of the holding wood by sticking the bar into the undercut? Leaving both corners of course, like two tabs with the center missing. Then cutting the rest of the backcut from either side?

 

[Zackman1801]

i had figured that was how to do it but wasnt sure. Our teacher had us do this on some red pine that was small enough to do a single stage but he had us do this because it minimized the fiber pull since red pine does it big time.

thanks guys! :greenchainsaw:

 

[smokechase II]

Open Face and face center bore

Open Face technique has pluses and minuses.

One minus is that usually it calls for a shallow face.
Make that same angled face and go further back into the tree, say 1/3rd diameter as a guideline rather than the 80% diameter of the tree that is commonly used.

That deeper face, along with a very wide open face, will help get the bar further in.

 

[palogger]

in our area alot of guys, including myself, bore the center for 3 main reasons reasons

1. minimize fiber pull

2. reduce the risk of barber chair, especially in white oak and hickory

3. and for the reason stated in the first question, allows the use of a smaller bar
- most professional sawyer will state that using this method it is possible to cut trees that are 2.5 times the length if the bar

 

[hammerlogging]

yea, must be talking about boring in the face. Cut your face cut. bore in the face, hollow out the middle (yesw leaving the all important edges) then proceed with your double bores. You're fortunate to be doing this stuff for school. Ask about small diameter tree wedging- thats a cool GOL technique using face boring, if the teacher doesn't know I can fill you in.

 

[smokechase II]

Fiber pull

That is a good point.
The face center bore eliminates some of the fiber pull and that saves lumber eventually.

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In British Columbia, Canada they have instituted a serious certification program.
Take a look at:
http://www.bcforestsafe.org/content-program-fallers/fallers-06-03-01-field_evaluation.pdf

A lot of this is different than what you are going through right now.
Perhaps worth your time in the long run to look at all the techniques you can.

 

[smokechase II]

Barber Chair

I can't find any one that has had a barber chair with either a face center bore or rotten wood in the center that connects with the hinge.
To back palogger up may I suggest again that the face center bore is worth your time.

Boring on hardwoods and dead wood is somewhat dangerous.
Hope you're being broke into that safely.

 

[gavin]

it might be this method of preventing barberchair for heavy leaners? takes wood off the sides and lets you race the backcut faster. (the picture attached).

I haven't heard of using face boring to reduce fibre pull/barberchair, and i would definately not use it on heavy leaners (which are subject to fiber pull) because you're in front of the tree and cutting off wood that holds the tree. the tree could potentially let go with you in front of the tree and your saw and arms stuck in the face cut.

the reason why you would face bore is if the tree is more than twice the size of your bar and you couldn't finish the back cut because your saw won't reach all the way in. another method of doing this is cutting out a "window" on the back which is essentially removing a big block (like if you were putting in a jack, but bigger) so you can stuff the power head into the window and cut deeper. as you can guess this takes a ridiculus amount of time. i saw it on a cedar stump that was about 9 food diameter in Port Eliza.

 

[clearance]

Ask about small diameter tree wedging- thats a cool GOL technique using face boring, if the teacher doesn't know I can fill you in.

Do you mean cut the backcut first, place a wedge by hand, cut the undercut and then pound the wedge? Thats what we do here, simple and sweet, I have seen something here for little trees, but it was complicated.

 

[hammerlogging]

We don't back cut hardwood timber at all (pros). We bore in behind the hinge, establish the hinge we want, and cut out the back, this porevents all fibe pull and barberchairing (except in the most extreme cases) So when we bore in the face, there is still tone of holding wood left. this fellow is talking about directional felling technique as opposed to your west coast methods which are more appropriate for your tall straight timber with relatively balanced crowns.

The small timber wedging is the regular face cut, bore in the face straight through the tree out the back. Place wedge in your narrow cut in the back, then clip the sides about 1 inch below the cut where your wedge is (standing behind the trees direction of felling of course) Then pound it over. This enables you to use your 12" wedges (all a cutter should carry) with maximum leverage (back of tree) without bottoming out your wedges on the hinge- the tip of the wedge will pass through the hinge and straight out the front allowing you to continue pounding despite it being small timber. Be sure when you clip the sides you leave the hinge wood on the sides! Better than boring, then placing the wedge in the side, where once you clip the back and pound, the wedge is liable to squirt out the back. Always good to be able to manage small timber fast and effectively so we can cut junk out while we cut the good timber so we're not just high grading. If its not clear I can expand for you later. remember, you need hinge wood on the sides (ok to clip the sap wood to stop pull on wood on the sieds of your butt log but you need something to direct the fall)

 

[smokechase II]

right on

Zackman1801:
There are several things Hammer is saying that are right on.

This boring straight through the tree, (a center face bore, yes it is), if you have enough diameter to work with is the cats meow on smaller trees.
Maybe a 7 inch diameter, (where cut), is about the absolute limit for this as far as this goes on the small end.
I would suggest that you can make this cut first, establish - I said establish - your 12 inch wedge, then do your face. Then hammer to snug, then slightly offset finishing back cuts.

12 inch wedges are better for driving, less force required but still the same lift accomplished if the rear height is the same as a shorter wedge.
They don't want to pop out as much.
They stack better and quicker.
You can even do a second bore directly below the first and double up wedges that way. However two of these 'stacked' wedges only accomplish about 1.5 regular stacked, (due to the second kerf removing part of the lift platform).

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Now if you want to get really sneaky;

Do your center face bore from the face side first.
Then starting at the half-way mark redo the original bore with some pressure on the tip angling down. (You are using the tip to widen that back-cut side of the bore.) Do as needed to securely establish two stacked 12" wedges.
Face cut and back cut as necessary.
(A sawyer cannot widen a cut from the starting point. But can do so when coming back out from the interior. This has application for establishing wedges also if one has a 'sit back'.)

This way you get the usual lift from stacked wedges.

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Although the best way to stack wedges is where they angle strongly.
This makes them even easier to drive and they hold better. But that only has application in wider diameters.

 

[hammerlogging]

Ill tell you what, I did an independent study on adult education and logger safety programs, of course ran by the BC program, and was totally impressed. That level of completeness is great. Now I'm sure you have a fair number of bullheaded folks and old timers that say its all crap, but the future is professionalism. Down in the south you're lucky to find someone who even uses a hinge! There are some good cutters around, WV has some good cutters I've cut with. I'd like to cut on the west coast for a while- directional felling (bore cuttting and all) is necessary here in HW timber, but man I dig all that Humboldt style, so much finesse, so many variations- I cut with/for some fellas from NorCal for a spell about a year ago. But they broke too much wood, you just can't backcut our timber. Plus, there is huge opportunity to get some yarders running in the Appalachians, all thats holding me back is some experience working around yarders (probably have to head west to get some exp. with it), and of course, a little cash. All in due time. But if any of ya'll beat me to getting a yarder (with a killer crew that actually knows how to log and cut well, not easy to build but certainly possible) going here in the Appalachians, hire me.

 

[Dibbs]

Try these.

 

[techdave]

Hi HL, why does the wood break, barberchair? or...

Originally poste by hammerLogger

"But they broke too much wood, you just can't backcut our timber."

Do you mean because its Hardwood? Rotten in the heartwood?

Do you mean they barberchaired it? Or that their hinge did not last and control the fall?

I can see how you might have to modify the backcut by using a release tab, or setting up a triangular backcut, or boring the backcut thru the face.

Do you really not backcut at all?

Please let me know, I am abviously totally clueless about cutting with NO backcut! DOH.

 

[hammerlogging]

Didn't more than flip through the attachments, the Maine one looked like Game of Logging based info. Hey, but it sure is cool to talk top someone from Ireland. I'd say the BC stuff beats it, but thanks anyway. On one side I'd say I'm done with that project anyhow, but on the other case I'd say its always good to keep learning so on and so forth.

Everyone ( but the most red of red) use face cuts of one variation or another. The Cali dudes would back cut as you would Humboldt style. But our hardwoods generally have heavy crowns and there's nearly always a lean- the closest we have to fir/redwood style timber would be our poplars, whats the word decurrent/excurrent which is which? damn. supposed to know that stuff. Anyhow, so when you backcut anywhere where the lean is on your side you end up with the tree falling before you can get the hinge narrow enough so yes you get atleast some barberchair effect. Since our butt logs are by far most valuable part of the tree, mills really frown on this breakage, if its a mill job, or you're doing the landowner a disservice, one way or another your wasting value, not to mention the danger with barberchairing. Remember its HARDwood so no matter how perfect your chain is sharpened it won't cut as fast as softwoods. So we bore in behind the hinge, establish the perfect hinge (often only 3/4 inch on even a 30" white oak- 10% diameter maximum rec. hinge width) and cut out the back. Its safer and better. Try it on any stem 7" diameter or so or bigger, smaller than that its hard to bore, just have to backcut the small stuff.