Would You Climb This One?

[1I'dJak]

Ouuuch! I'd climb the tree closest to it...tie in....and chuck my grapple into the high crotch... give her a few good tugs and see how the top wobbled... if no good, i'd abort and hopefully get my claw back...if alright, then i'd swing over, and avoid climbing it from the bottom up...you can throw in all this formula crap but there are so many variables to consider that 'true' eperiments try to eliminate...

 

[Kneejerk Bombas]

My source for the info is a TCIA Pocket Guide: Identifying Hazard Trees.
I will now recite a paragraph to illistrate my point of 10% as rule of thumb but like I said you need to take into concideration other factors in the tree.

"The table below shows the minumum wood thickness that constitutes a 50% strength loss. When using this table, remember to subtract the bark thickness from both the diamter measurements (D-tape value minus two times the bark thickness). Stregnth loss will be greater (trunk weaker) if there are cracks, cavity opening or other weakening factors. In those cases, the thickness of sound wood for a given trunk diamter will need to be greater than the values listed for it to be climbable.

Diameter of Stem/limb * Thickness of sound wood *
10" 1"
20" 2"
30" 3"
40" 4"
50" 5"

*Not including bark"

If you still do not agree with what I have said then go and take up your case with TCIA being you must be more educated then the indiviuals that work there.

As well that tree can still be climbed but as the ways to go about doing appartly do not matter to jokers on this thread. Improvise and think outside the box it isn't rocket science here. I have done tree like it before and probally will do them again. If you are too incompetant to do the job then pass it on.

What we have here is good information being used incorrectly.
The tree in the picture is dead, cracked, and has huge holes. There is no sound wood at all, and more importantly, it is not an unbroken cylinder of sound wood. The excellent information from the TCIA has nothing to do with this tree.
Also, Ekka correctly pointed out the percentage of wood in the chart is 20%, not 10%, but again, it doesn't apply to this tree.
You are right, given time and ropes, a good arborist could basically elevate himself up next to the tree and do the removal, but when I read, "climb a tree", I think putting a lanyard around it and spike up, or throw a rope in the tree and climb that way. This tree could not be safely climbed that way.

 

[DDM]

This tree is why some of us have Bucket trucks.Woodchuck where are you in SC?

 

[adkranger]

To further Ekka's post; another factor to consider in stem strength is rigidity/flexibility. To that end whether it is hollow inside the 10-20% good wood or just punky wood. I would think that a rotten stem with solid sapwood and punky center would be preferable to work on than a hollow "tube". The rotted wood will still offer some strength to the stem, even if just from a flex stand point. Just compare using the cheap, hollow pole saw sections from the foam filled ones (both made from same shell material). Or imagine a paper towel tube's strength vs. the same tube filled with sand and ends duct taped closed. Which would be stronger? The linear strength is in the paper tube in each situation but the filled tube will endure more flexing before failure over the hollow one I suspect.

Merely considering the static strength of the "tube", or good wood in the stem, say 10 or even 20%, is not enough. You must also consider the lateral and torsional forces applied both initially supporting the structure and as you work the tree the stesses will change. What would concern me more with the Woodchuk's tree is the vertical split with that gaping hole more than a mere cavity alone. I was working Sugar Maple many years ago with an extremely weak crotch that actually failed after the weight was removed from it. It wasn't shock loading from lowering since we false crotched into a separate tree. Near as I could tell the tree had compensated for the leader's poor attachment point for so long that removing the weight put enough reverse stess or tension release to the cause failure. It would have been disasterous had we not tied off the leader stem to the good stem prior to working it. It was quite interesting situation, hard to explain unless you were there to witness for yourself. Injured and stessed trees are the toughest to dope out. Ever have a storm damaged tree's stem practically explode after removing weight and stress from it. Tension, stored energy has to be considered in trees like this. My .02.

 

[Soul Assassin]

No, but I would use rigging to get it manageable, then drop it if I could.

 

[John464]

I would bet I could break that tree at the point pictured with just a throw ball and zing it line.

bucket, every arborist needs one or should have a source that can provide usage/rental of one. If you attempt to climb trees that dead you are out of your mind. Forget the percentages, they are not needed on this tree. You can see with your eyes it is not safe to climb. Nor is it safe to set line in another tree and rig the tree as a whole.

 

[Kneejerk Bombas]

This tree is why some of us have Bucket trucks.Woodchuck where are you in SC?

The only problem with bucket trucks is the tree that needs work isn't always accessable, although this one certainly is.
Plus bucket trucks ruin good climbers.

 

[JohN Dee]

Do you consider your life valued at the price of this job? If so climb, if not get an EWP to get you up there.

 

[diltree]

My first response was obviously a joke.......I felt that this thread truly warranted a joke, sorely based on the fact that there are some that are considering this tree "safe to climb". I always respect others opinions in this forum, yet in this case I'm actually shocked there is a debate on whether or not this tree is safe to climb. My first impression was that woodchux was joking when he posted the picture and in fact the question was proposed in a sarcastic manner.
With that said, my professional opinion is: " No do not climb this tree, under no circumstance should any one climb up this tree" . There are many other options; tie into another tree or use a bucket Truck, if there is no truck access or tie in points; rent a spider lift. If there is no access for a spider lift, perhaps cranes can be used. If you cant get a crane in, then Rent a helicopter designed for lifting and ride out with the pieces. Any unsafe tree can be done without the need to compromise your Life.

 

[EngineerDude]

Mostly ignoring the question of whether I'd climb this tree or not (Personally I wouldn't. No way! Seeing that one picture of the defect, I just simply wouldn't feel safe on an emotional/intuitive level), I'll instead make some comments that might put the question of whether 10% wall thickness is "safe" or not into a different light. As Ekka noted, the TCIA reference mixes concepts here; diameter on the one hand, and wall thickness on the other. If you think about it, wall thickness really relates to radius of the tree, and so to be able to be compared to diameter on an apples to apples basis, this value must be doubled.

So this "10% wall thickness" is really 20% of diameter, and if you do the arithmetic of calculating the percentage of good wood associated with this remaining ring, it's 36% of the original total.

So what TCIA appears to really be saying is that with 36% of the wood remaining, you still have (nominally) 50% of the "strength" of the tree. (By the way, it's not completely clear exactly what they mean by "strength"; ability to withstand a bending moment, or ability to withstand a compressive load, or ...?)

Bypassing the question of what they mean by "strength", certainly it's more intuitively believable that 36% of the remaining wood could yield 50% strength than it is to say that "10% wall thickness" does so. Then, when you consider that in a bending scenario, the fibers of the outside of the tree are under the greatest stress (the ones on the side in the direction of the bend are in compression, and the ones on the opposite side are in tension), and these stresses decrease as you move to the center of the tree (the fiber at the geometric center is under neither tension nor compression), having the 36% of the tree being those fibers located in the areas where the stress is greatest renders this even more intuitively believable. That is, the fibers where the wood is good are in exactly the right location to do the most good.

So from an engineering mechanics and strength of materials viewpoint, I think this 10% wall thickness is probably a pretty good number. This assumes, that the tree is a nice uniform hollow cylinder, without major imperfections. All bets are off if the tree has major defects that compromise this critical load-handling capability of the outer fibers.

By the way, adkranger's point about hollow versus solid is valid. As stated above, the distribution of loads varies from maximum at the edges to zero in the center, so the presence of additional fibers beyond the 10% thick wall certainly helps, albeit to a decreasing extent as you move to the center.

 

[Kneejerk Bombas]

So this "10% wall thickness" is really 20% of diameter, and if you do the arithmetic of calculating the percentage of good wood associated with this remaining ring, it's 36% of the original total.

Good catch on the math. A 50" cylinder with 5" wall thickness can be thought of as a 50" circle with a 40" hole, which leaves 36% sound wood.

 

[ORclimber]

A solo climber died in Lake Oswego about a week ago. The top 10 feet of a decayed cottonwood broke out, and the guy fell 70 feet. OSHA said it was the climbers fault for not doing proper tree inspection.

 

[Climb020]

I checked the website and that pocket guide sells for $4 ... surely you'd take that into account as usually you get what you pay for. Go and read some real books.

Surely you are joking here. Are you implying that the price of the knowledge dictats how valueable it is? I mean all the info online is free (mostly), but if following your logic, that info has no value including videos posted by yourself. Right. it's free so it has no value. Ok, you can take your foot out of your mouth now.

I miss said about the 10%. What I meant and what I typed came across as 2 different things. I ment per side of the tree, so that if is is a 10" tree you need 1" on every side, so that way anyside of the tree has a 10% of good wood. When looked in a whole it is 20%, sorry if this was confusing.

2 floating false crotches for climbing and rigging, to get it done, that is if the pieces cannot get bombed.

 

[EngineerDude]

One more thought on the strength aspect of this. The orientation of the defect strongly affects its impact on the strength of the tree. You really want to have fibers present in the parts of the tree that are in tension and compression. Translated into this scenario, you really want that hole to be rotated 90 degrees away from the direction of bend. The math gets really complex to quantify the strength reduction if the direction that the hole is pointing is coincident with the direction of the bend, more than I'm interested in pursuing, but suffice it to say that the impact is VERY significant (and this is is irrespective of whether it is on the tension side or the compression side).

Can't tell from the pics. Are they taken from the same location? And what is the direction of the lean?

Whatever the answer, I still personally wouldn't do it. But how strongly I'd advise against it depends on the orientation of the defect.

 

[Blinky]

I wouldn't climb it, wouldn't even be tempted. Nobody can really judge whether it will stay together and if you mean to drop the top out of it, the dynamics would be really sketchy.

I can't tell for sure from the pic but it looks like an expert faller could rope it and drop it safely it in one piece, if not, then some kind of lift equipment makes more sense.

 

[adkranger]

Mostly ignoring the question of whether I'd climb this tree or not (Personally I wouldn't. No way! Seeing that one picture of the defect, I just simply wouldn't feel safe on an emotional/intuitive level), I'll instead make some comments that might put the question of whether 10% wall thickness is "safe" or not into a different light. As Ekka noted, the TCIA reference mixes concepts here; diameter on the one hand, and wall thickness on the other. If you think about it, wall thickness really relates to radius of the tree, and so to be able to be compared to diameter on an apples to apples basis, this value must be doubled.

So this "10% wall thickness" is really 20% of diameter, and if you do the arithmetic of calculating the percentage of good wood associated with this remaining ring, it's 36% of the original total.

So what TCIA appears to really be saying is that with 36% of the wood remaining, you still have (nominally) 50% of the "strength" of the tree. (By the way, it's not completely clear exactly what they mean by "strength"; ability to withstand a bending moment, or ability to withstand a compressive load, or ...?)

Bypassing the question of what they mean by "strength", certainly it's more intuitively believable that 36% of the remaining wood could yield 50% strength than it is to say that "10% wall thickness" does so. Then, when you consider that in a bending scenario, the fibers of the outside of the tree are under the greatest stress (the ones on the side in the direction of the bend are in compression, and the ones on the opposite side are in tension), and these stresses decrease as you move to the center of the tree (the fiber at the geometric center is under neither tension nor compression), having the 36% of the tree being those fibers located in the areas where the stress is greatest renders this even more intuitively believable. That is, the fibers where the wood is good are in exactly the right location to do the most good.

So from an engineering mechanics and strength of materials viewpoint, I think this 10% wall thickness is probably a pretty good number. This assumes, that the tree is a nice uniform hollow cylinder, without major imperfections. All bets are off if the tree has major defects that compromise this critical load-handling capability of the outer fibers.

By the way, adkranger's point about hollow versus solid is valid. As stated above, the distribution of loads varies from maximum at the edges to zero in the center, so the presence of additional fibers beyond the 10% thick wall certainly helps, albeit to a decreasing extent as you move to the center.

Good catch. Your AS name is indeed quite appropriate. Are you an engineer, tree guy or an engineering treeguy?:biggrinbounce2: All very intuitive, valid points, along your follow up post. Nothing is 100% trying to dope out a specific tree in a picture, but I think the consensous is correct in not climbing this in a traditional manner, if at all. Even with a secure, remote anchor I don't think I'd like to be tied to that stick swinging big pieces.

 

[Magnum783]

Forget that. I am just now recovering from a fall out of a pine that broke under my feet when I cut the top out. Not good, rent a bucket truck, call a crane, it is not worth it at all to get hurt. Plus the recovery really sucks.
Jared

 

[ROLLACOSTA]

Woodchux you should be able to answer the question yourself! if you can't decide if the tree is safe to climb or not, then imo you need more experience..

I hear a lot of you guys talking about being an ARBORIST,you don't or shouldn't need to be an arborist to decide if a tree is to dangerous to climb or not!!

 

[Gumneck]

Forget that. I am just now recovering from a fall out of a pine that broke under my feet when I cut the top out. Not good, rent a bucket truck, call a crane, it is not worth it at all to get hurt. Plus the recovery really sucks.
Jared

Jared

Have you posted about your fall yet. If so, how about a link to the discussion. If not, how about talking about it for others to learn by. Maybe some pics of part of tree that broke, etc.

Tks, hope your getting better.
Tom

 

[Magnum783]

No, I will start a thread now.
Jared