Rope Cabling for Static Use

nyclimber

nyclimber

When using either Cobra or Wesspur's Tree Guard in a static application, do you typically go up a t size (in rope) for the strength requirements based on the diameter chart?

For example, on a 12" stem that you are installing a slack cable in for dynamic, you would use a 2t setup, BUT if pulling it taught because there is a crack, should we increase to 4t rope?
 
I believe the accepted practice is to switch to a steel cable system. You can however still use the slings if you wish to stay non invasive. The literature for tree guard shows the use of steel cable, thimbles, and clevis' to interface with the eyes of their slings.
 
As far as upping the size sling? I would think its a per case decision. How much force to pull them together? Its not going to hurt more than the bottom line of the invoice to up the system if you're unsure.

...and finally you can always contact tree guard. They say to contact them if you run into an abnormal system design. If you do, post back with their answer!
 
Thanks for your thoughts- I will go with a larger t size rope for now and will email them to see what they have to say about it.
There is a lot of grey area when it comes to this topic and when you should switch to steel cabling, is it due to diameter, strength required or simply preferred for all static applications?
 
First off, I'm not actually positive dynamic cabling systems are actually described in the ANSI standards for tree support systems. So that would be one reason there isn't a clear standard on when to use what. I'll have to look into that...

From what I've heard and read it seems to be general practice (if an arborist practices using dynamic system s at all) to switch to steel systems mainly when supporting an active failure. There are many who only use steel, even without an active failure. I've used steel without an active failure, and I may again...

However since I have had more experience with dynamic systems, especially tree guard I'm pretty sold on it being a better option for many situations. First because it is noninvasive, and second because it allows the tree to continue to respond to the loading of itself and the wind/weather.
 
OK I had an email discussion with Drayer in Germany, of course it was hard to understand clearly what he was saying because of the language barrier, but what I got is this:
When you need to support branches statically, always switch to steel cable because the rope textiles have some elongation that permits movement, and you can get a tighter hold using steel cables.
He said you match the sling size with the stem size (same as dynamic chart), and affix a cable with eye instead.
So you were right Sonshine Tree.
 
So I guess the 2 different rope elongation types that they sell; 5% and 20% are for you to choose for a dynamic application based on the flexibility desired.
 
I saw a lot of 4-ton size used in France but yes there is always some stretch.

Buy the new BMP it is only $8 for fuxakes. It is still sadly stuck in 'traditional' systems but does incorporate some dynamic and minimally invasive throughcabling, so it is worth it. I prefer a 7/16" hole clear through rather than the compression and mtc. with dynamic, generally.
 
Do you guys have a preference of tree guard over cobra or vise versa for dynamic systems? I've only used cobra and steel, would like to hear more about tree guard.
 
Kevin- I have researched both and there are pros and cons to each, although I am partial to Tree Guard myself.
The main pro to Cobra is that it allows for adjustment when the stem grows in diameter, and with Tree Guard, you must replace the slings and the rope after 5 years or whenever you do your inspection.
The main difference between the two systems is that with Cobra, you are using the rope around the tree and with Tree Guard you have slings that you place, much the same way you would use a cambium saver on a DDRT system.
Plus with Tree Guard, you can use the slings with a steel cable for a non invasive static system, and you can't do that with Cobra or any other of the rope cabling products.
 
I have not used cobra, but it seems similar to branch saver that treestuff sells. Since I tried trees guard I don't think I'll go back for anything large at least. Branch saver makes sense for ornamental stuff where potential loads are much less.

Treeguard uses webbing slings with sewn eyes. The webbing is 3-4" wide so the load is spread on the surface pretty well. With branch saver they reccomend sleeving the rope with cordura tubular webbing which does help with girdling w little, but the pressure is still much more concentrated.
 
Who makes the Wesspur tree guard. I use the Yale Guardian (in a custom gray color that is very camo!!) I like the simplicity of the setup.

We do dynamic and we do steel. If it's a static load, the tree is getting the steel treatment.

To me, steel makes more sense on small ornamental trees. It is way more camouflage!


love
nick
 
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