Cabling the Cracking Maple

treeseer

first pic is a crack that opened just this summer.
The smaller trunk is failing. Attached is a picture with red lines where the trunk could be cut back to (all cuts to lateral branches, and leaving enough foliage to keep the stem alive) and an orange line where a cable could be installed.

Comments?

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willem

Looks like a good plan, but will the cable be static or cobra like system. I would recommand a good pruning as you do( up to 50 % of foliage of big limb). Also install a "storm"cable. A saftey device to catch the big branch if it breaks. I would allow it to move no static line.
It's a realy big crack. When rot starts to occur in crack it will become a safty hazard. Lifespan of this tree is fairly comprimised.
Continues saftey checks and pruning will be nesecary.
If it stood over here in Holland on grounds of local authorities I think it would be removed.

treeseer

" will the cable be static or cobra like system.

HARD STEEL 14 ton--no movement desired.

"I would recommand a good pruning as you do( up to 50 % of foliage of big limb).

maybe 20%; why more?

"Also install a "storm"cable. A saftey device to catch the big branch if it breaks.

that is what the cable does--why another?

"I would allow it to move no static line.

why?

"It's a realy big crack. When rot starts to occur in crack it will become a safty hazard. Lifespan of this tree is fairly comprimised.

who knows?

"Continues saftey checks and pruning will be nesecary.

yup annuall checkups

"If it stood over here in Holland on grounds of local authorities I think it would be removed.


others?
it's astreet tree and the city will not cable that's where we come in

willem

I would recommand a good pruning as you do( up to 50 % of foliage of big limb).

maybe 20%; why more?

Because I would set up a non-static system and there for a larger reduction will be neccesary than in a static sytem.

Also install a "storm"cable. A saftey device to catch the big branch if it breaks.

that is what the cable does--why another?

I meant install one cable in a non-static system, no static cable.

"I would allow it to move no static line.

why?

Because when branch is imobilized by a static system, the branch gets lazy and will not try to strengthen the weak spot. Let the tree try to solve it's own problems. Therefor I also reccomand excessive pruning. So the tree has a slow start in the strengthening of the cracked limb.

Eric Frei

I'm no cable expert but since there's such a clear difference in the sizes of the stems, and the larger left one is the dominant then why not cable like my new yellow line above yours?



And yes, as it's a street tree the council would be concerned about liability if it does fail and impact a target.

Looks to me with parked cars and a house that targets are constant, big left stem could hit the house.

Perhaps another way the council looks at it is like this, inevitably the tree will eventually come out anyway, even if it is 20 years time. So are we prepared to invest the resources into this tree to manage it for that period of time with the risk it poses or do we bite the bullet now and remove/replant? If the tree offers little habitat value and is a common species it would be economically more viable to remove/replace. However, looking at tree decisions I can say that logic and economics often makes way to emotional decisions.

The next thing some-one will argue is the aesthetics or amenity value, plus the greenhouse value. They'll say over the next 20 years the tree will provide bla bla bla of benefits. The counter argument is over the 100 years the new tree will whip it's ass anyway and cost less.

We all also know that you're looking at remedial work, and once again a proactive approach by the council would have prevented the situation in the first place. That could have been pruned and could have been cabled long ago.

What is the probability of failure after remedial works?
Are the parties that would affected by failure consulted and what is their attitude to retention/removal?

In this post New Farm Jacarandas there's a link to a video just above the embedded picture. At 3.24 minutes into the video listen to what the lady says, now that's why experts have to make calls not lay people.

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treeseer

"why not cable like my new yellow line above yours?

that indeed may be the way to go, depending on the form of the trunks at those levels. i have only seen those pics, not the tree.

city put a red X on it for removal because they do not cable. it's on private property, in the road easement so it is the landowner's call, with a civic association maybe chipping in..

"as it's a street tree the council would be concerned about liability if it does fail and impact a target."

true that is why i'm proposing heavy reduction along with cable.

"Looks to me with parked cars and a house that targets are constant, big left stem could hit the house.

true.

"inevitably the tree will eventually come out anyway, even if it is 20 years time....

Or it could be 40 or 60 or...no one knows.

"So are we prepared to invest the resources into this tree to manage it for that period of time with the risk it poses or do we bite the bullet now and remove/replant? If the tree offers little habitat value and is a common species it would be economically more viable to remove/replace. However, looking at tree decisions I can say that logic and economics often makes way to emotional decisions."

This {logic and economic} argument is regularly trotted out, with highly skewed data. Cost to prune and cable <$1k, cost to inspect annually minimal, re-pruning maybe every 3-5 years, just like any tree.

"The next thing some-one will argue is the aesthetics or amenity value, plus the greenhouse value. They'll say over the next 20 years the tree will provide bla bla bla of benefits.

Not blablabla, but Dollars, Mr. Logicandeconomic.

"The counter argument is over the 100 years the new tree will whip it's ass anyway and cost less.

Highly speculative. what is the average street tree's life?

"That could have been pruned and could have been cabled long ago.

Absolutely should have happened. but here we are.

"What is the probability of failure after remedial works?

Extremely low, with a 7 ton cable.

"Are the parties that would affected by failure consulted and what is their attitude to retention/removal?

The neighbors are all fighting for retention, despite the city's refusal to cable. One savvy consulting arborist said cabling should work; that is how i got the call.

Eric Frei

Guy, I dont get it.

The tree is on private property but the council removes it?

Isn't the footpath owned by the council?

Just need this area cleared up as over here any tree on the footpath is the council's tree and we can get fined for mucking about with it.

If it is on private property and the council does remove it, then why? And how does that process work? And where is the line drawn, like will they remove one from a backyard too?

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kiwi_tree_steve

Hey there

im a big fan of the noninvasive system COBRA, for many reasons. given that it is designed to allow the tree its natural movement in the canopy, using the shock absorbing unit, this lets the tree, continue on in its efforts to grow reaction wood, and re - balance the stresses involved in it just standing there. also its self adjusting system, ease of use...........

i think i would install a COBRA system, at the point of 2/3rds of the distance from the fork to the tip of the branch being " Braced" ( braced used loosely, as IMO Cobra should be used to "catch or re - direct the path of the branch if or when it fails)
http://www.treeworld.info/attachment...5&d=1220157397

then give it a small prune to reduce the weight, but not alot , 20% - 30% as i dont really want to stress the tree any more that i have to.

i would also include an after care inspection plan 3 visits over the next 2 yrs, to evaluate and keep an eye on things

steve

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Eric Frei

I'm fairly consistent in my posts on this and also aware of cabling but am no cabling expert.

But the dynamic vs static debate and applications go on for ever, there's tons of example and discussion in the past.

There's also been comments in this thread of dynamic by others.

Anyway, I see this as a static cable job because it was the trees natural swaying BS that broke it in the first place. A crack is just that, it wont join up, it can in reality only get worse. In this situation I cannot see bolting through that union going on due to location and size so a static cable to prevent any further cracking seems the logical solution in this instance.

However, you could have a low static cable and a dynamic further up and prune less off. The dynamic further up would also help in taking some of the whip out of stems above the static cable. Just pinching Jim1NZ's idea.

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Therrin

Wow that's a big crack if you can fit your hand into it like that. Seems to be a great spot to catch water and start something growing in there....

So um... I'm confused. If you know it's a problem, and granted, it MAY last 40 or 60 or 20 or 10 years.... Mayn't it also come apart next year?

Seems to have alot of targets too... mainly the types of targets that people occupy too (cars, houses)... so.... whats more important, the houses, cars and people's wellbeing... or... whats left of the lifespan of the tree?



So lets say you cable it. Hey thats niffty. But lets say it breaks anyway. Okay, so the top doesn't fall down and smash into something, but even if you added both cables in, it still looks that there'd be sufficient movement at the base for the broken stem to swing in and smash a car or a person.

I've found that homeowners are generally not the brightest when it comes to trees, including the care of and hazard assessment. (granted... I'm not the brightest either). But frankly, I'd think that Joe Homeowner's opinion as to retaining it or not would be pretty pointless. What are they going off of?
"Well it's a pretty tree so yeah we wanna keep it there"

That's pretty bright. Maybe you have to be a real to value an already damaged tree in a target rich environment over the targets themselves which include human lives. Eh... I can't figure that one out.

Seems to be the neverending argument.






OH! I almost forgot!! What's to say that your 7 ton cable (or 100 ton cable, or whatever) holds up just fine, but the OTHER stem that it's bolted to doesn't bust off as well given the additional strain after the first one goes?

Or is it more like "well we just hope it doesn't work out that way, and that noone gets hit if it does" ??

TrevMcRev

I'm a big fan of cobra, and have recommended & installed plenty of it.

But in this case i agree with steel as the bracing material.

This isnt just a typical 'potentially" weak union. It is already failing.

If the tree is to be retained, then it should be braced to limit or remove movement at the union.

I also agree with ekkas angle of the brace, i think it works better with the difference in size of the stems.

Treeseers 20% pruning looks plenty.

Interested to know more about who's responsible for what with naturestrip trees over there...

treeseer

The steel will hold the trunks together--if i have any doubt i will brace rod down low.

It's on private property, in a public road easement. the city marked it for removal but owners and neighbors all want to keep the tree. Cities here seem less involved than councils there--if it's off their plate then generally they are happy, and the less known the better.

It amazes me how so many preach the virtues of dynamic, even when there's a hand in the crack.

pruning will focus on lever arms not volume, but with the severity of the failure i will err on the side of lessening the load

treeseer

just saw it and climbed it yesterday. I don't see a need to reduce the height, but everything else is as specced from the pictures:

Cracked Sweetgum Report 080913

ASSIGNMENT
September 13 2008 Mark of the Association asked me to assess the condition of a tree at Road in , and describe reasonable management options. Per the request of the city arborist, I was assigned to determine whether a support system could comply with the American National Standards Institute (ANSI)’s standards on support systems, so I refer to ANSI A300 (Part 3) 2006. I am not certain whether my client is the City of , the Association, both, or neither. I agreed to inspect the tree as soon as possible given the emergency conditions.
OBSERVATIONS AND DISCUSSION
The tree forks out a foot above the ground. The smaller fork has a moderate lean over the road and powerlines. Lower branches have been shortened to avoid the powerlines, but higher branches extend over them and over the property across the street. The larger trunk has a slight lean toward the residence. The fruit is in its green stage, with more water and more weight.

A crack between the trunks has opened this summer and is now 1-2” wide. There is no visible decay inside the crack at present, but the wood is highly likely to decay in the future. There is a small amount of decay in a ground-level wound facing the street. The trunk shows no defects, and the wounds from pruning branches appear to be sealing well. There is one fork above the yard with included bark. Many branches on both trunks have heavy ends. The top of the tree has less leaves.

Both trunks form major scaffold limbs about thirty feet up. I climbed the tree to complete my inspection, and in light of the considerable hazard I tied the trunks together with rope to prevent further failure and damage. I read the relevant portions of both the ANSI standards and the Best Management Practices (BMP’s) published by the International Society of Arboriculture. I saw the last 5 panels of the Taylor’s sidewalk lifted, and the grass near the tree is brown, indicating aggressive root expansion and water uptake. The asphalt pavement on Road has small cracks, allowing infiltration of water and nutrients and gas exchange.

MANAGEMENT OPTIONS
1. A 3/8” Extra High Strength (EHS) cable properly installed below the scaffold forks would comply with ANSI standards. Rated at 13,600 pounds, it can support the defect and work to prevent further opening of the wound.
2. The branches can be shortened, reducing strain on the defect and perhaps allowing the trunks to be pulled closer together when the cable is installed. If sufficient pruning is done every 5 years, and decay does not spread rapidly, the cable may be strong enough on its own.
3. The trunks can also be bolted (braced) together, but ANSI standards do not require this treatment. The ISA BMP’s state that brace rods are used to stabilize forks that have cracked. Propping and guying are support methods that do not seem to fit this tree.
4. Removing the five sidewalk panels and adding 4-6” of loose soil and sand before possibly relaying them would provide more rooting area for the tree. So would mulching an area extending in an arc around the tree, where the grass is brown and woody roots protrude above the surface. Chopping the leaves that drop this autumn and spreading the chips from the pruning work about 4” deep would more closely approximate the nutrient recycling and root protection in the tree’s natural growing conditions. The rooting area beneath the gravel driveway could be aerated and fertilized, according to its needs. Testing the soil, adjusting the acidity, and adding prescribed nutrients might also improve the tree’s ability to strengthen itself, over time.

The work should be done by a Certified Arborist experienced with the treatments specified, especially pruning over power lines and designing and installing support systems.
This concludes my report. I can clarify any portions of it upon request.

Sincerely Yours,

BCMA

newguy18

If it were me,i'd see just how sure the clients are on keeping it,if they wanted it,i'd probaley add through bolts at the base,you know to help stitch the crack shut.Other then that,I'd probabley go with Eric's idea for the cable,just seems correct to me.After that i'd thin the entire canopy so wind could go though it easier instead of blowing against it.If it were in my neck of the wooods,it would be a stump right about now.

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old schooler

Eric Frei

Guy,

You mention adjusting the "acidity", is that common speech over there as we say adjusting the pH and give the range best suited for the tree species. Like check and adjust pH to 6.8, critical depth to 30cm.

Also, we have been running an interesting thing on aeration which also talks about decompaction, two different things however often thought to be the same, most likely because people decompact with air. Much evidence is showing that organic liquid additives can do the decompaction. Have a thread running here with lots of info. Soil Aeration Experiments| Grade Changes| Compaction| Decompaction

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Knotahippie

This tree seems like a prime candidate for soil building agents, if it's not all good.

Could help fine absorbing root growth, build defence/callus with low nutrient, high carbon insulation...wood chips.

Get rid of the lawn, it's toxic!

It's nice to see folks/homeowners keeping trees "of character", as long as it's maintained/safe within reason.

These are the kind of trees that I stop the work truck to look at or folks out on sunday takin' a walk stop to look at.

Cool man, cool