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Posted

Can you help settle an argument? The debate with a climbing buddy is what is better in an anchor system. One opinion believes that the best system is rope around a tree and tied off by a locking biner to a figure eight. The other opinion is that the rope should be wrapped around a tree and tied back onto itself in a figure eight. Understand that this debate is betweem newbies who lack experience...but the point of an argument is which is stronger...or are they both sufficiently strong methods to anchor a TR?

 

Thanks

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Posted

If you are doing a true high-strength tieoff, it should not matter as there should be no tension in the knot or biner itself. The idea behind the high-strength tieoff is that there are no knots in the system to weaken the anchor. Carabiner on a 8 bight is a hell of a lot more convenient than tying a rewoven 8 around the working line, and prevents nylon on nylon rubbing when weighted (as in a highline, etc).

Posted

quote:

Originally posted by Mtn. Dude:

Can you help settle an argument?

 

Maybe

 

One opinion believes that the best system is rope around a tree and tied off by a locking biner to a figure eight.

 

Can you clarify this? Is the fig8 in the end of the rope, how many times is it around the tree?

 

The other opinion is that the rope should be wrapped around a tree and tied back onto itself in a figure eight.

 

Again, where is the fig8?

 

the point of an argument is which is stronger...or are they both sufficiently strong methods to anchor a TR?

If they are what I am picturing, they are both good.

 

Iain - I don't think he is talking about tensionless tie offs, although he may be. I also think in the second case, he is talking about tieing off to the tree like you would a harness, not a tensionless with a knot instead of a biner?? [Confused] Or maybe he's just trolling... [Razz]

Posted

Well if I had a rope and a carabiner, and I had a BFT in front of me and wanted to anchor to it in the strongest manner possible, this is what I would do:

 

-

 

But I don't think that many wraps are necessary on most tree bark.

Posted

Obviously, this wouldn't work to anchor a toprope belay because there is no way for rope to be pulled in by the belayer. In that case I would get some 1" webbing and do a wrap-3-pull-2 anchor with some lockers.

Posted

thank you for clarifying iain. I was having trouble figuring out how you could top rope off a rope that was tied off [Razz] ... but then what do I know? [Wink]

Posted

My apologies for the misunderstanding, again new to sport and unable to articualte the question well. Iain your picture is the heart of the argement. Should a biner be used to tie back onto the rope or should the rope be tied directly to the rope...whcih I think has been addressed here.

 

Thanks, no trolling just a legitimate question from a real newbie. [smile]

Posted

Again, the biner is totally legit in that case because it should not be under tension anyway. It just sits there as a backup in case the bark on the tree shears off under rotational stress or whatever else might happen. The whole concept is that there is no knot in the system weighted, so you maintain the maximum strength in your line. This is also why prusiks are used to anchor lines under heavy load, as they act as a load-limiting clutch to protect the line from failure.

Posted

In general, my understanding is that you want to avoid running your climbing rope around a tree trunk, due to potential soiling of the rope with sap, and damage to the tree (girdling) by the rope if it's pulled around the tree (see Long's climbing anchors and/or FOH). However, if you are using a long piece of webbing or chunk of rope as your anchor link between the tree and the toprope 'biner, as in a situation where your tree is some distance from the top of the cliff, then the illustration as posted by Iain is probably appropriate. As always, with an anchor, you should confirm that is meets the SRENE concept (Strong, Redundant, Equalized, No Extension). Long also has a good anecdote regarding the required diameter amd root establsihment of a tree. Essentially, the tree should be alive, at least 4-6" in diameter, and have a well-established root system.

Posted

quote:

Originally posted by Dru:

this weekend I placed some bolts to replace a 6" tree that was not well rooted. RIP tree. It was fun when Snoboy and I trundled it though!
[Eek!]

And then I had a major blonde moment. We were walking off the top and there was this tree in the way and I was, like, "Whats this tree doing on the trail Druuuude??"

 

Oh wait, I am blonde.

[big Grin]

Posted

I think this debate is missing the point. Mtn Dude, you asked which of two systems of tying a rope around a tree is better, one with a biner (which kind of sounded like a lasso slip-knot or girth-hitch kind of thing, where the 'biner is the "pulley", until Iain mentioned the very legit high-strength tie-off. But I don't think that's what you had in mind...) and one which just sounded like a rewoven figure-8 around the tree.

Yeah, for single anchors, if you happen to want to use a rope rather than some webbing to build the anchor with, they're probably both ok. My preference would be for the rewoven figure-8.

 

The bigger question is why you want to anchor a rope around a tree in the first place. As I understand it, the high-strength tie-off is mostly used for rescue work, and works very well to secure a rope without weakening it with a knot. If you actually want to climb with the rope, though, you're not going to be wrapping it around any trees (except maybe for the odd emergency rappel, and even then, slings are better if you have them, or you face the risk of a stuck rope). You're especially not going to be tying it off in one of the methods you described and then top-roping off of it.

Ask someone who knows about the basics of building climbing anchors, or look in the John Long book mentioned by Glacier. Building good anchors for climbing is not a trivial skill. And don't try to toprope with your rope around a tree - very bad for tree, very bad for rope, very bad in general.

Posted

Is the picture posted above the "high strength tie-of?" If so, it looks like a good way to anchor a rope to a tree to me. The multiple wraps, if snug, will probably eliminate any spinning of the rope around the tree and minimize damage to the tree and to the rope.

 

If you are using a rope as a long runner so you can set a top rope using a tree that is far back from the edge, be aware of the possibility that the rope can swing back and forth (and sweep rocks from the cliff-top or suffer some abrasion) if your climb is not directly below the tree. Also, consider the possibility that a climbing rope may stretch when loaded, even with a relatively small load from a top-rope fall.

Posted

quote:

Originally posted by mattp:

Is the picture posted above the "high strength tie-of?" If so, it looks like a good way to anchor a rope to a tree to me. The multiple wraps, if snug, will probably elimi

I think if you asked 10 rigging guys to rig a "high strength tie-off" you would get ten very similar anchors to the above picture. Not a very useful anchor for anything outside of rescue, but it is certainly one of the strongest, if not the strongest, anchor available with today's technology, assuming a bomber tree.

Posted

All anchors systems will have flaws. The idea is to eliminate as many of those flaws as possible and\or necessary in order to be safe.

 

Those big rings on the Great Northern Slab at Index are good anchors [big Grin]

 

[ 11-25-2002, 05:08 PM: Message edited by: Cpt.Caveman ]

Posted

Mattp that was the idea. This was in a situation where trees were too far from the edge and webbing was not long enough, the discussion was to use a static rope hitched to two trees and extend it beyond the edge. The debate was how it should be tied in.

 

Thank you all for you comments, will refer to the anchor book and continue to seek advice on building the best achor until I find someone willing to let me second and learn. [Confused][smile]

 

[ 11-25-2002, 06:06 PM: Message edited by: Mtn. Dude ]

Posted

quote:

Originally posted by Cpt.Caveman:

(snip)

Those big rings on the Great Northern Slab at Index are good anchors
[big Grin]

I always figured somebody is going to be extra surprised when one or both of those pop.

Posted

Isn’t something missing here? Given that Mtn Dude did say that the anchor is for a TR, then it seems to me that the other end of the anchor rope that Ian’s picture does not show, would have some kind of knot, with biners, and another rope going through them for the actual TR. So the anchor rope would already have a knot as its weak point rendering the high strength tie off at the tree of no extra value.

 

Ian’s second suggestion with webbing, for a TR anchor, is the way I’d go.

Posted

quote:

Originally posted by ScottP:

quote:

Originally posted by Cpt.Caveman:

(snip)

Those big rings on the Great Northern Slab at Index are good anchors
[big Grin]

I always figured somebody is going to be extra surprised when one or both of those pop.

That'll be the day [laf]
  • 1 month later...
Posted

Those big rings on the Great Northern Slab at Index are good anchors

 

They will be rock solid until the day they pull out. I don't think they were ever intended to last a century. How many hundred year old bolts have you ever rapped from?

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