Top movement during topping

[pantheraba]

We've probably all seen the video where the climber plays rag doll when the top pops.

I just found this video, they titled it "Stem Wobble". It looks like a reasonable amount of movement to me. Could it have been made even "softer" or less? maybe by changing the type/size of face cut made? (you can't see what type he used, I am just raising the question).

Would a Humboldt type cut let the top slip off more than push back against the spar?

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[brendonv]

If you continue to cut through the hinge while its going over you will get less and less wobble. When the hinge is in tact it's wanting to push the tree the opposite way of the fall.

Thats what I've heard at least.

[MasterBlaster]

I always put a snipe in unless I want the top to jump out a bit. The stem wobble in the video was because he used a wedge. If he woulda just cut it off it woulda ploped over with minimum trunk movement. The thicker the hinge the greater the catapult effect.

[okietreedude]

arbormaster says to leaave some limbs on the bottom below the cut and it will help reduce the sway.

[MasterBlaster]

That's called "dampening" and it doesn't really reduce the sway so much as it absorbs the energy.

[Frans]

arbormaster says to leaave some limbs on the bottom below the cut and it will help reduce the sway.

Actually, the idea is to leave branches staggered up the entire length of the stem.
Not alot, just a few here and there evenly spaced and hopefully growing in different directions.
My experience MB, has shown me that it really does reduce the bounce effect (by reducing the 'push' of the top coming off).

[MasterBlaster]

I just can't see how that's possible. The limbs have no effect on the top. The limbs affect only the spar, dampining the shock thereby "reducing the bounce effect."

:D

[Tom_Scheller]

The top only has so much energy to push the spar. The more limbs you leave, the more mass the spar has, the more energy it takes to set it in motion, and the less it will move.

TS

[MasterBlaster]

We'll agree to disagree. :drink:

[Tom_Scheller]

I was gitt'n error messages trying to post, hence the double.

TS

[MasterBlaster]

Not a problem, bro. (http://www.gypoclimber.com/showthread.php?t=9477)

[RIVERRAT]

The top only has so much energy to push the spar. The more limbs you leave, the more mass the spar has, the more energy it takes to set it in motion, and the less it will move.

TS
I am not understanding this at all. Mass in motion equals energy. The more mass the more energy. After it gets moving any way.

What you describe would only make sense if the limbs left attached some how changed the direction of energy at the hinge.

I will try rap my mind around this for a bit

[wiley_p]

Butch you are right is saying that cutting up more wood the piece tips over with less sway on the pole. Having limbs left on the tree adds weight, and reduces any force imparted by the top pushing off. Adding a snipe helps, as you said unless you need some horizontal distance to clear a target. Go top a a central leader tree with most of the brush still on below you observe movement. Do the exact same procedure on a clean spar with a top, you will have more movement.

[stehansen]

I thought you were supposed to cut a wide face cut so that the face wouldn't close until after the trunk was done pushing on the top and was on it's way back. And have a small hinge.

[Tom_Scheller]

The limbs make the spar heavier. So it is harder to push.

Just think about trying to push a water barrel. Empty it's easy. Full it's hard. No difference with a tree limbs vs no limbs.

How you cut the top changes the energy that the top can exert on the spar, but the top only has x amount of potential energy to start with. By tinkering with the notch and hinge you can change how much of the spar's potential energy is converted into "spar wobble."

TS

[RIVERRAT]

OK,we are talking about leaving limbs "BELOW" the top.
Now this I can understand

[RIVERRAT]

Stehansen, that is correct

[arborworks1]

Less hinge wood has always seemed to reduce the catapult.

[brendonv]

What's a "snipe"?

[MasterBlaster]

<jsu>

[brendonv]

Not what I was thinking.

I was once told to make the cuts in the pic below, on a tree such as a hickory. They are very shallow on each side under the hinge, maybe 1 inch deep. I thought it was so the top broke off easier? Or was I just wasting time/doing something stupid?

[MasterBlaster]

Yep, that's what it looks like.

I have no idea what the cut you're talking about does.

[RIVERRAT]

No you weren't being stupid. They are called relief cuts. That is what I was explaining. With out relizing we where talking about a snipe cut.

[sotc]

brendan, your little cuts are to stop the hinge wood from peeling a strip of wood down to your flip line.
as far as the video goes it looked like the top stayed on a good long time and went very smooth. could have been just a long skinny pole

[lumberjack]

+1 To Willie's definition. They keep the bark left intact by the hinge from peeling down into your lanyard, called wing cuts typically.

[wiley_p]

Yep, that's what it looks like.

I have no idea what the cut you're talking about does.

Those cuts are called "sap cuts" On some trees in the spring and early summer it is prudent to make them cause you will get fiber pull from the butt and it can throw you out of lead.

[RIVERRAT]

Wing,sap, relief cut. It's weird the different names of the same such stuff. All it seems depending on the place you learned.

[pantheraba]

I can't find my copy of "The Art and Science of Practical Rigging" but I am pretty sure they call those "kerf cuts"...they are to prevent fibers from the top from ripping down into your lanyard/safety that is just below the topping cut.

I have had Burnham caution me to not do them too close to the top cut...too close can compromise the hinge wood.

"Nipping the ears below the hinge may be usefull, for some species...I have never felt the need to do it when falling...up in the tree with a lanyard below your face is a different story. If you DO do it, go very shallow and at least 4 inches below the hinge. It's easy to compromise the most important holding wood, so be cautious there. Your hinge held fine, so you did well there.
"

The info comes from this thread:

http://gypoclimber.com/showthread.php?t=6352

[stehansen]

I had my belly sucked up against the trunk one time. I do the relief cuts now.

[lumberjack]

Wing,sap, relief cut. It's weird the different names of the same such stuff. All it seems depending on the place you learned.

Yeah, like scarf, notch, gob, underbed ect ect.

[MasterBlaster]

Great Googely Moogely!!! (http://www.youtube.com/watch?v=hSAXLayoMKI)

[RIVERRAT]

Yeah, like scarf, notch, gob, underbed ect ect.

Exactly. Along these lines. Could some one please define Stump shot? I have heard it used in so many different ways

[sotc]

broken hinge

[MasterBlaster]

Could some one please define Stump shot?

STUMP SHOT: Two inches or more height difference between the horizontal cut of the face and the backcut. The difference in height establishes an anti-kick step that will prevent a tree from jumping back over the stump toward the faller.

From here, (http://www.osha.gov/SLTC/etools/logging/glossary/glossary.html) although I don't agree with their definition of a snipe.

[Bounce]

As I understand it, to reduce "stem sway" you make it so that the top is perpendicular to the stem when the hinge wood finally breaks, which is when the cut finally closes. I usually do this by starting my face cut with a regular notch and then finish with a humbolt (which can be thought of here as a really aggresive snipe), so I have actually removed two 45 degree notches of wood from the face cut, resulting in a tipping motion of 90 degrees before hinge breaks. Lastly, I continue to narrow the hinge wood right up until it breaks - not enough to eliminate it's ability to steer the top, but enough so that it breaks quick and easy with very little pop.

I can't really see how leaving a few branches would add enough mass to make much of difference. I understand the idea of how a more massive stem is harder to shove around than a less massive one. But we're talking a relatively small difference in weight on a lot of trees; in the trees I work in, the branches are probably about 15-20% of the trunk's mass. Sure it helps, but not enough so most people could notice.

[Stumper]

Mass dampening-(stuff left below the topping cut) works. Cutting more as it goes over helps. A snipe or opened face can help...oddly so can a narrow face and popping the top off before it moves very far. The video did not show an uncontrolled top departure but it sure kept whipping after the initial push back. I am a tree climbing chicken. I wouuld have moved up higher and taken a fraction of the weight and length in my topping cut.

[RIVERRAT]

I am not a logger or "BIG WOOD" forester.I would like to learn but will never be such a climber.Not at present any ways.
In cases such as this I am sick & tired of hearing the slant that is put on most "TREE WORK" that favors the logger & forester type work. That makes out any, that do any thing less than the biggest trees, less than achieving the benchmark.
Most work on trees now days is of a different nature.
I love what I do!!
I have a scar on my face & eye that would have caused some of other vocations to take work else where. It was an accident that I learned from & am gratefull wasn't worse....I am glad we have the likes of Wiley P, Burnham &

[RIVERRAT]

I am not a logger or "BIG WOOD" forester.I would like to learn but will never be such a climber.Not at present any ways.
In cases such as this I am sick & tired of hearing the slant that is put on most "TREE WORK" that favors the logger & forester type work. That makes out any, that do any thing less than the biggest trees, less than achieving the benchmark.
Most work on trees now days is of a different nature.
I love what I do!! Dont any of you try to make me think or feel less for it!
I have a scar on my face & eye that would have caused some of other vocations to take lesser work else where. It was an accident that I learned from & am gratefull wasn't worse.The fact is there are many others like myself here that just do "TREE WORK" ......To Be Continued
What was I taliking about /dammit I just nodded off/ Butch would you let me continue this tomorrow

[Frans]

RiverRat, my experience with tree work is getting trees down in small areas. It takes alot of skill which is a different skill set than dumping big trees. Each skill is it's own and one is not less than the other.

[squisher]

Naww, hug a logger you'll never go back to trees.:P

[RIVERRAT]

Well I double posted last night. Forum seems fine now. I guess I was venting a bit from the aftermath of a conversation I had earlier on the phone.

The talk of leaving bottom limbs when popping a top out, while I am sure it works & is in fact something to keep in the mental tool box just got me thinking more about all of it .
Frans, like you said it is 2 different skill sets.That can at times cross over. To my way of thinking there is room for respect of both

[Frans]

no one has ever disrespected me for doing tree work and being a isa cert. arborist

[Stumper]

Frans, Of course not. There are so many other reasons to dis you.




















:P

[squisher]

And I might add I've been disrespected many times in the past for being a logger. Try going out to a bar in Tofino(hippyland,Vancouver Island)after pulling a shift in camp :roll: .

[stehansen]

Lastly, I continue to narrow the hinge wood right up until it breaks - not enough to eliminate it's ability to steer the top, but enough so that it breaks quick and easy with very little pop.

I'm usually shutting off my saw and getting set as soon as I hear or see the top moving.

[stehansen]

And I might add I've been disrespected many times in the past for being a logger. Try going out to a bar in Tofino(hippyland,Vancouver Island)after pulling a shift in camp :roll: .

People are dumb sometimes.

[MasterBlaster]

People are dumb a LOT of the time.

[Old Monkey]

I don't top very many trees like that anymore unfortunately. I liked what Bounce said. In my mind I think it would be best to cut less than a 45 degree face cut so by the time the tree is perpendicular the holding wood has separated.

About leaving branches below the top in an even pattern like Frans mentioned, it is more than the weight added to the spar. Because the weight is held out from the trunk the balancing force is increased. Imagine trying to balance a teeter totter with two equally weighted objects two feet off center vs. at the ends. Having the weight farther from center adds more stability. That said I don't see myself having a use for that technique any time soon.

[rumination]

Here's an old classic.

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[MasterBlaster]

I can't believe the saw didn't kill him!

[Blinky]

I'm in the same boat as Frans, expensive targets and small landing zones are what I do best... I like doing precision work. It's a different discipline than logging but anybody that puts wood on the ground with a hand held saw makes the grade in my opinion.

About that top... that's just the right amount of sway to me, nice and smooth, plenty of deflection... those rides feel really good to me. I use wide 70 to 90 open face notches on tops like that unless I want them to jump. The ride is more sudden with jump cuts but it's still not bad.

The bad ride problem comes when you have to rig the top and your groundie is less than smooth at running the rope. I go small when I have to rig'em.

[rumination]

I can't believe the saw didn't kill him!


I know, it looks like it just about clocks him in the head!

[Blinky]

Oh yeah, the top I was talking about was Gary's... that palm is pretty wacked.