Video of Cobra System on windy day???

Re: Video of Cobra System-Use a hybrid system

What about using bolts at the union and cobra but without the shock absorber??? Maybe even putting extra tension on the cobra. That way you have a dynamicish system (more dynamic and less invasive the steel but less dynamic than regular cobra).

Make sense?
Matt
 
Re: Video of Cobra System-Use a hybrid system

I use GEFA for cabling, you can get it in different dynamic settings and works better as cobra. Cobra has the strange effect that it can work itself out with loading and unloading because off the structure off the fibres.

Don't know if GEFA is selling in the USA.

see the site : GEFA cabling
 
Re: Video of Cobra System-Use a hybrid system

[ QUOTE ]
The oak in the vid would likely split all of the way to the ground. There is no fusing going on at the codom. The wound wood is flowing over each side but not blending.


In order to calculate the mythical 2/3 point for the upper cable location you need to measure from the ground, or, where the tree would split if you don't use braces.


[/ QUOTE ]

Tom,

I'm wondering how you would predict that this is the way it would split, i.e. what about the tree's anatomy gives you clues that this kind of failure is likely?


Great thread! Go Cabling Forum!
 
Re: Video of Cobra System-Use a hybrid system

td...The oak in the vid would likely split all of the way to the ground. There is no fusing going on at the codom. The wound wood is flowing over each side but not blending...

ot what about the tree's anatomy gives you clues that this kind of failure is likely?

gm your answer is clearly stated above.

O and until you measure the rot and describe targets, risk tolerances and soil conditions, this speculation will wander. get up there with your helmetcam on, scoop out the rough stuff, and insert a yardstick, for starters, maybe?
 
Re: Video of Cobra System-Use a hybrid system

From this perspective (in the video) some "NO PARKING" signs might be in order.
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Re: Video of Cobra System-Use a hybrid system

Target is the house.

I need to film the other side of the split. I'm gonna climb and thin it out fairly hard. I'll check for decay then.

I will likely install a steel system as well, not sure? Owner likes the cobra and doesn't like the idea of drilling, but he's basing that on no tree knowledge.

Tollerance = owners love these trees, 1 reason they bought the house. I told them it is a serious defect and "anything can happen". But I also said I will do what I can to prevent. Thin out, new cable?, brace?, TGR.

Soil conditions = compacted clay, been trying to talk him into huge mulch rings.

(it is my buddy's house so he is not a client, all work done at no charge and in return he takes care of my web page, its nice when the buddy system works)
 
Re: Video of Cobra System-Use a hybrid system

I've re-read these threads and at the risk of wasting another 5 minutes of your time and some bandwidth, does this summarize what would be a possible approach (mostly as detailed by Tom - but I want to make sure I get it all:

1. Look at the union some more - dig around. It's prbably not fusing.

2. Do some reduction pruning on the co-dom but only a bit, and any other selective pruning that may relieve unwanted stress.

3. Install one through rod just below the crotch - including doubled washers and paying attemtion to removing bark.

4. DON'T install more rods over the union (as is sometimes done) because there is too much tree weight above the union and more static bracing might create a new bending point. (This is where I'm a bit unsure).

5. Install a steel cable well below the 2/3 point to act as a more flexible version of a rod (alternative to point 4).

6. Re-install or leave the dynamic cable high (honoring 2/3 rule here?) to allow natural movement but to relieve some of the possible increased pressure during movement down at the lower bracing points.

Is this right? I think this answers Matt's question which I also had and I think it was answered by Tom in a way.
 
Re: Video of Cobra System-Use a hybrid system

"In this tree there is still a LOT of wood above the codom union. Installing a steel cable down low serves the purpose of a flexible brace. It's not good to install solid braces where the tree may flex sideways. The braces will get cycled like paperclips and become weak. Using steel cables instead allows some rotational movement and supports the weak codom. "

Tom, I took this to mean a possible substitute for threaded rod--no?

"I'm gonna climb and thin it out fairly hard. I'll check for decay then."

mac, you'll assess the fork and plan the support system before pruning, right? The objective for and scope of the pruning depends on the condition of the fork, and design the incoming support system, right?

If your client likes the tree, hard thinning will give him less to like First plan then prune then cable.

Subordination means to lessen competition with the main leader; that means take off what hits it first, and reduce ends, second. But if the support is strong then pruning needs are minimal imo.
 
Re: Video of Cobra System-Use a hybrid system

Macrocarpa,

Your Cobra installation in this structure, and especially modest-sized maturing tree is fine, although appears a bit slack.

If structure of cable host is rigid, installation without shock absorber is perfectly acceptable, especially when primary stems reside so close together.

Viewing (as well as filming) trees in wind is a great practice for those of us with the interest. Although I suppose the activity is like that of lawn keepers watching grass grow.

Our (aged) English instructions for Cobra indeed highlight product not "designed" for use in structures with included bark but that was more of a liability clause than reality. If anyone were to ever produce instructions for static cable they should likely take the same precaution.

Great thread BTW.
 
Re: Video of Cobra System-Use a hybrid system

Tobe, your catalog puts it well--included bark = static (p 147). The codit issue is less with minimally invasive through-cabling. p. 146 has the unfortunate typo about annual inspections--ANSI says "periodic", and the arborist recommends the period. could be 5 years...

Good thread yes but will be better when we hear how much rot is in there (I am such a pest!)
 
Re: Video of Cobra System-Use a hybrid system

This week is booked, hopefully next week I'll climb that tree with my camcorder, examine decay and post it when I do.

Thanks all!
 
Re: Video of Cobra System-Use a hybrid system

Guy,

Your opinions on cabling/bracing are well respected, most certainly by me. As a rule, the "recommendations" about static and dynamic use are solid, perhaps I should have installed the word "exception."

The aforementioned typo (misspeak actually) was fixed today as you'll see in the not-to-distant future. Thanks for letting me know ...on the Buzz.

Stop by some time.
 
Re: Video of Cobra System-Use a hybrid system

Sure thing, Tobe. My stepkid will be at UNCG next year so I will get up that way more often. And actually I called about the typo a while ago, but was not sure the message got through. Your staff is not used to getting corrections on the catalog, because so few are warranted.

Pleasure doing business with you!
 
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