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shu2kill
Aug 14, 2008, 2:13 PM
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hey, do any of you know the strenght rating for the Triple Figure-Eight Loop ???
http://www.layhands.com/Knots/Knots_TripleLoops.htm
i would like to know how much does it decreases the rope strenght.
thanx!!
(This post was edited by shu2kill on Aug 14, 2008, 2:17 PM)
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j_ung
Aug 14, 2008, 2:14 PM
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Clicky! 
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ja1484
Aug 14, 2008, 2:54 PM
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shu2kill wrote: Hey, do any of you know the strength rating for the Triple Figure-Eight Loop?
Strong enough.
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GeneralZon
Aug 14, 2008, 3:46 PM
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What are you planning on using the triple 8 for? Just curious.
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acorneau
Aug 14, 2008, 6:28 PM
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shu2kill wrote: hey, do any of you know the strenght rating for the Triple Figure-Eight Loop ???... i would like to know how much does it decreases the rope strenght.
My guess is that it should be about the same (if not slightly better than) than a standard figure-8; maintaining 75-80% of single-strand strength.
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shu2kill
Aug 14, 2008, 6:31 PM
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thanx.
a friend asked me to investigate the numbers. he said something about building anchors, but he wanted to know the strenght, to determine if its better than the knots he currently use or something.
thanx!!
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irregularpanda
Aug 14, 2008, 7:13 PM
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shu2kill wrote: thanx. a friend asked me to investigate the numbers. he said something about building anchors, but he wanted to know the strenght, to determine if its better than the knots he currently use or something. thanx!!
If you want the real numbers, adatesman would probably know for sure. You can rest assured that it is strong as hell(or at least as strong as the pieces used and how they are connected), and inherently redundant.
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jon5rockjock
Aug 16, 2008, 2:18 PM
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I just recently checked out the triple loop figure 8. and it is interesting. I immediately thought about an anchoring application. However,....i suppose that if any particular piece in the system popped you would see a shockloading of sorts occur. there also seems to be a lack a top shelf although there are methods around that by adding an Alp Butt and then a preferred knot further below it to anchor into for the belayer. I personally prefer the the standard nylon cordelette and very rarely stray from this method. There are 100 ways to skin a cat though and I tend to do what seems tried and true for me.
I am curious on the technical data/testing of the double figure 8 or "Super 8". Please refer any links if you know or come across them.
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knudenoggin
Aug 17, 2008, 3:38 AM
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shu2kill wrote: a friend asked me to investigate the numbers. he said something about building anchors, but he wanted to know the strength, to determine if its better than the knots he currently use or something.
This is a misguided query: the "numbers" won't be any indication of whether
to use the knot in comparison with some other knot's numbers. For starters,
you have really no valid reason--probably--to conclude that the "numbers"
you might see apply to the particular physical knot you will tie, or for the
particular material you use. Here we're concerned with a triple-eye knot:
how do you think it would be tested, to generate some "numbers"?
--once for each eye in isolation? --and after others bore some load,
or without that? --or two of three eyes ... ? ... and on & on.
(If you dress & set the knot as shown on the Layhands site, expect it
to be weaker than it would be in some other dressings--he'd put a pretty
hard bend at the mainlines' entry.)
Of concern with a multi-eye knot is inter-eye feeding of material if an eye
is unloaded (anchor point failure). This one should be pretty secure.
*kN*
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shu2kill
Aug 17, 2008, 5:16 AM
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well, i agree the numbers wont be 100% accurate for the particular knot i can do, but i think they would be close.
i asked him what he needed the knot for, and told him your replies, and he said that, for an anchor, he puts each loop of a double figure 8 on a biner. but the sharp bend also reduces the strenght. so, he wanted to see what would be stronger, a rope with a triple figure 8, or one with a double. the reasoning was that the triple could divide the load in 3 parts. but maybe the loss of strenght due to the knot itself, was bigger than the loss of strenght due to a double 8 with each loop in a biner.
thanx!
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summerprophet
Aug 17, 2008, 5:23 AM
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Tell your friend that the knot on its own is going to be stronger than the knot you use to tie in with.
In short, certainly strong enough.
I am assuming he is using his lead rope to create the anchor, if he isn't there are far easier and faster methods I would look into.
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knudenoggin
Aug 18, 2008, 2:01 AM
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shu2kill wrote: ... the reasoning was that the triple could divide the load in 3 parts. but maybe the loss of strength due to the knot itself, was bigger than the loss of strength due to a double 8 with each loop in a biner.
Consider this: a Fig.8 loopknot in 11m rope pulled with a 'biner in the eye
breaks at the knot. ONEye, noTwo, noThree--one.
*kN*
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gunkiemike
Aug 23, 2008, 2:10 AM
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Get your friend off this notion of "accuracy" in testing for these types of knots. Consider this - the angle between eyes will affect the load seen by the knot and therefore tensile strength. So in a perfect world you'd have a matrix of angles and failure loads. Absolutely useless for making field decisions. Bottom line - a Fig 8 loop type knot in the climbing rope is strong enough. Now turn off the computer and go to bed. 
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