Seeking advice for pollarded eucalyptus

[treevet]

I think one thing that has not been discussed in either current running threads with the dynamic cable system the subject of conjecture is (I think) the proponents advocating this system used for codoms are primarily recommending for codoms WITHOUT included bark.

In this defect there would be pinching and wounding within the included bark and often infection. There would also likely be cracking in the defect caused by the two codoms "pushing" each other apart. Not a good situation to allow the movement in the dynamic system.

But furthermore....quite often a crotch involved with a codom grows into an included bark situation so why not be a visionary and go static as maybe it will be needed later when the codoms become included and then the job will have to be REPAID for?

prior to splitting would this have been a candidate for a dynamic? I know not but this an exaggerated example. Just food for thought.

 

[jefflovstrom]

I think one thing that has not been discussed in either current running threads with the dynamic cable system the subject of conjecture is (I think) the proponents advocating this system used for codoms are primarily recommending for codoms WITHOUT included bark.

In this defect there would be pinching and wounding within the included bark and often infection. There would also likely be cracking in the defect caused by the two codoms "pushing" each other apart. Not a good situation to allow the movement in the dynamic system.

But furthermore....quite often a crotch involved with a codom grows into an included bark situation so why not be a visionary and go static as maybe it will be needed later when the codoms become included and then the job will have to be REPAID for?

prior to splitting would this have been a candidate for a dynamic? I know not but this an exaggerated example. Just food for thought.

Food for thought, Removal. Dynamic and static are not life savers.
Jeff

 

[treevet]

Food for thought, Removal. Dynamic and static are not life savers.
Jeff

That tree was in the process of removal and just an example.

My guess is your boss calls the shots on what is retained.

Cabling IS a live saver. That tree caught a little earlier would have been saved....by me....with a couple of bolts and a static (it bothers me to even have to refer to this cable in these terms in comparison to the elastic one that has no use around here).

 

[treeseer]

But furthermore....quite often a crotch involved with a codom grows into an included bark situation ...

how often? Think about what would be involved for bark that is curling up into a ridge to change direction and curl down instead. Maybe, very gradually, over many years

And a fork with no included bark can still be strained by heavy ends, which cannot be reduced without costing too much in form or function. That is one scenario that has called for dynamic.

prior to splitting would this have been a candidate ...

That crack could be braced right now; why not?

 

[jefflovstrom]

That tree was in the process of removal and just an example.

My guess is your boss calls the shots on what is retained.

Cabling IS a live saver. That tree caught a little earlier would have been saved....by me....with a couple of bolts and a static (it bothers me to even have to refer to this cable in these terms in comparison to the elastic one that has no use around here).

Your guess is wrong. I may see my Boss a few times a year.
Jeff

 

[treevet]

That crack could be braced right now; why not?

I meant candidate for dynamic....not. Yes is should have been braced right NOW ....but never was and I discovered without anyone else noticing it near a playground and it in my wood pile right now.

 

[treevet]

Your guess is wrong. I may see my Boss a few times a year.
Jeff

apologize for wrong assumption then

 

[jefflovstrom]

apologize for wrong assumption then

Ah, Its OK, Just following the thread. All is good!
Jeff

 

[Ekka]

I'm respectfully waiting for any proponents of the current dynamic cabling systems on the market today, to explain how supporting a tree with a material weaker than the tree, makes any common sense whatsoever from a safety or durability standpoint?

jomoco

Because we are not supporting the tree. :monkey:

Does your lowering rope have to be stronger than the tree? :monkey::monkey:

 

[outofmytree]

Also what if the property ownership changes or the installer gets busy and forgets about where he has these systems strewn all over town. Looks like a sure stem girdling future for this tree (not so with static). There is no reason not to put in a static cable if there is a defect such a weak co dom here and the installation time after watching this, would probably be won by the static (esp w 2 guys). Wound inconsequential no matter the "poor compartmentalizer".

I would not use one persons demo video as a guide to speed of cable installation TV. I bet if someone new to static steel cable installation was to make a video it would look like 2 guys wading through treacle at 20 metres too. Arborists I know who have used both systems say the dynamic installation process is roughly twice as fast to install at the anchoring points but the climbing speed between those points is much of a muchness. Over here the material costs also favour dynamic systems again by a small but appreciable margin.

I have a question about the formation of reaction wood in multi-dom trees like the ones mentioned in the OP's. Your analogy with the two baseball bats made me think a little and I wondered why you only discussed "in and out" motion and not lateral motion too?

Use this diagram if you will to illustrate where you feel a dynamic system would fail to do its job. May I ask we assume that such a system has been correctly installed which means there is no restriction of motion on the cabled stems under "normal" weather conditions and there is sufficient slack in the "girdling" loops to allow for growth between 2-3 yearly inspections.

 

[outofmytree]

I'm respectfully waiting for any proponents of the current dynamic cabling systems on the market today, to explain how supporting a tree with a material weaker than the tree, makes any common sense whatsoever from a safety or durability standpoint?

jomoco

This would be a good question if indeed the tree was being supported in its day to day motion. But as the name (dynamic) suggests, this style of cabling, at least in the applications being discussed, is not intended to support the limb. It's primary purpose is to prevent the limb, in the event of failure, doing harm to someone or something. Perhaps this rough diagram may help.

Epicormic limbs on Eucalypts seem to break straight out from the main trunk and most commonly on the direct opposite side of the prevailing wind. So in Perth, the two limbs marked NE would be the most likely to fail. The choice of dynamic cable is governed by the mass of the branch but they range from 2tonne to 8 tonne so there is a solution for most Eucs with this sort of post topping growth.

 

[treevet]

There are a lot of statements, related assumptions, musings, wonderings, etc. here in your 2 posts oomt. Could you isolate the questions so they can be addressed. I don't think the system designed by Wohn is applicable to your illustrations with apparent included bark even in his opinion.

One might wonder why challengers of this system are so adamant in their arguments.

The answer is I/we put in a lot of cable support systems. I usually accumulate a dozen or so so I can net a couple $grand and then go out and do them in one day. This happens maybe 6 times during the busy season. It is quite profitable.

People that install cables in accordance with ANSI standards do not want to have to bid against inferior systems (possibly because in their opinion... a. they are easier/faster and require less knowledge to install or b. "cost substantially less in materials") and have the homeowner not know they are comparing apples to oranges.

Kind of like showing up to bid a large pruning job and the guy you are bidding against is selling a roundover hatrack.

 

[outofmytree]

Sure thing.

Lets take the OP's tree/s as a basis for discussion. Our client has epicormic regrowth on a Eucalyptus camaldulensis that has no visual evidence of potential failure but is adjacent to some form of significant target. So there is the possibility of failure rather than a gaping crack like the picture you posted a little earlier.

It's because exposure to wind causes dynamic movement and forces to be applied on the wood that it REACTS to by putting on more mass in the form of tension or compression wood.

I agreed with this post of Jomoco's.

Any time you shelter that tree by limiting the natural forces exerted on it, it becomes dependent on that support compared to an unsupported tree

And this one too.

I know E.camaldulensis very well. I have pruned or removed more of these trees than any other Eucalypt species and they have a well deserved reputation for dropping branches when under stress. A topped E.camaldulensis even more so. If our client insists on keeping the tree then the cabling system I suggested, similar to what is drawn above, allows the tree to do exactly what Jomoco said is so important.


What I am asking you TV, is have I misunderstood the importance of allowing this tree to create reaction wood to support its own weight?

When you gave your analogy of the two baseball bats you seemed to address only motion in and out (or up and down if you prefer) and did not say anything about lateral motion. Is that because lateral motion in your opinion is not something we should be concerned about or did I misunderstand your explanation?

I had another question pop up whilst typing this. What do you personally do, or suggest should be done, when their is no visible defect but, as in the example given, there is a real possibility of failure over a significant target?

 

[outofmytree]

I don't think the system designed by Wohn is applicable to your illustrations with apparent included bark even in his opinion.

6. codoms/ multidoms:
The system can be used to secure codoms / multidoms too and often enough was used in such cases. Therefore you have to connect every stem with its neighbour (e.g. as ring connection) and possibly crosswise with its vis-a-vis. Try to secure every load directions – that means back and forth as well as left and right.

I think this quote of Wohns shows quite clearly that he believes a dynamic system is in fact very well suited to this particular example. In fact he recommends the same ring connection method I drew above.

 

[treevet]

I think this quote of Wohns shows quite clearly that he believes a dynamic system is in fact very well suited to this particular example. In fact he recommends the same ring connection method I drew above.

The operative words here were "included bark" as illustrated by the v shape of the base of your illustrated codoms. Don't think he wants to allow movement of these. Can't speak for him tho.

 

[treevet]

Sure thing.

What I am asking you TV, is have I misunderstood the importance of allowing this tree to create reaction wood to support its own weight?

When you gave your analogy of the two baseball bats you seemed to address only motion in and out (or up and down if you prefer) and did not say anything about lateral motion. Is that because lateral motion in your opinion is not something we should be concerned about or did I misunderstand your explanation?

You may have a misunderstanding of reaction wood. Sporadic lateral movement is NOT going to result in reaction wood. The lean of the limb and related weight will as will perpetual prevailing winds.

Yes lateral movement is of concern and this is addressed by the configuration of the cables. Where does your dynamic system fit into this?
The static system limits it much more thoroughly without elasticity of the cable. Who needs the reaction wood? It has no physiological benefits!!

I had another question pop up whilst typing this. What do you personally do, or suggest should be done, when their is no visible defect but, as in the example given, there is a real possibility of failure over a significant target?

You know the answer to that.....I am going to put in an appropriate metal cable system. The "possibility of failure" defines the presence of a defect revealing itself.

 

[outofmytree]

Thanks for clear answers TV. See most Aussies are quite civilised and remember their manners!

So where the prevailing winds are SW as per my place, does the torque effect created on branches pointing NW and SE (at 90 degrees to the wind) produce reaction wood?

One other thing I wanted to ask and here seems as good a place as any. I have said a few times that we see the most epicormic failures to the NE here or opposite to the prevailing wind. Yet much of what I have read regarding wind created stresses suggests that it is the moment at which the wind drops and the branches return violently back to their original positons (and beyond) that produce the greatest strain on unions. So why doesnt the evidence match the theory?

 

[Boa07]

OOMT, when considering the forces created by violent distructive storms, concepts of prevailing wind direction are not all that useful. (Acknowledging that there can be other important factors in limb failure beyond wind speed and direction)

Destructive storms produce very very powerful downdrafts-microbursts together with powerful vortices which act to produce massive wind loading almost instantly (max wind gusts in the GAP storm Nov 12th 2008 were measured at 160-180km/h)

I have attached a schematic from the BOM to help clarify..

View attachment 127338

 

[treevet]

No systems are meant or capable of withstanding those extreme forces. Good info Sean.

This 500 year old oak I am charged with the care of was hit with a violent downshear and crushed the house adjacent to it. All bets are off with cables at this point. 4 other codoms were split open by this and we were forced to reduce the entire tree to this secondary canopy.

 

[outofmytree]

OOMT, when considering the forces created by violent distructive storms, concepts of prevailing wind direction are not all that useful. (Acknowledging that there can be other important factors in limb failure beyond wind speed and direction)

Destructive storms produce very very powerful downdrafts-microbursts together with powerful vortices which act to produce massive wind loading almost instantly (max wind gusts in the GAP storm Nov 12th 2008 were measured at 160-180km/h)

I have attached a schematic from the BOM to help clarify..

View attachment 127338

Thanks Boa. I did my apprenticeship in Port Hedland (category 1 building area) so the vortex affect of cyclones and the unpredictable nature of the wind speed and directions they produce is not new to me. Much as TV said, if that happens then all bets are off!

What I was asking regarding prevailing "normal" winds was, does the torque they apply to the main stem by applying pressure on branches at 90 degrees to the flow induce reaction wood? I have seen some interesting "butressing" develop on stems at ground level where the only force I could see at work was wind. Likewise I have seen interesting wood develop where the epicormic stems join the older wood and rather than vertical this reaction wood(?) is left and right....

One other thing I wanted to ask and here seems as good a place as any. I have said a few times that we see the most epicormic failures to the NE here or opposite to the prevailing wind. Yet much of what I have read regarding wind created stresses suggests that it is the moment at which the wind drops and the branches return violently back to their original positons (and beyond) that produce the greatest strain on unions. So why doesnt the evidence match the theory?

Anyone have an idea why this is so? I have not documented or photographed these observations but of the 4 sets of photographs I do have of epicormic breaks on Eucs all were on the East and 3 were NE. I have considered that the damage is cumulative rather than the work of one violent wind gust and the failure when it comes is in the path of least resistance. That still doesnt explain why SW branches don't succumb as readily if as I have read, the greatest force is applied when the branch "relaxes" after wind load is applied.