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pbcowboy77
Oct 22, 2002, 7:01 AM
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Does anyone use a "Self Equalizing figure eight knot" at anchors? If so, how well does it work. I know the knot but have not used it on a climb due to the fact that I've only seen it in a book and not in use. Pros and cons would be nice to know.
-Zac
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youareon
Oct 22, 2002, 8:55 AM
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The self-equalizing figure eight can be useful for tying into two or three points (depending how you tie it) but has a few drawbacks...
* uses up a fair bit of rope which could come in handy if the next pitch is long
* provides no masterpoint for belaying the second from the anchor
* anchor management is complicated if you plan on leading all the pitches (again no masterpoint)
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rrrADAM
Oct 22, 2002, 11:59 AM
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I've used it before.
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fishypete
Oct 22, 2002, 12:02 PM
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Another weakness with this system I read about in one of my climbing knots books is that when an anchor point fails, as the newly redundant loop pulls through it can melt a piece of the figure 8.
Probably not going to be significant unless you have really huge loops, but it is useful to know.
I hope it helps,
Fishy.
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tradklime
Oct 22, 2002, 4:23 PM
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My opinion, it is most useful when climbing on a single rope and anchoring into 2 or 3 bolts. Other than that there are better methods.
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hyhuu
Oct 22, 2002, 6:03 PM
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I've used it for my Grand Teton trip and found it to be very useful. Our criteria for using the rope anchor method were:
1. The climb was well within mine and my partner climbing ability (Self-rescue, belay-escape would be difficult.)
2. We switched lead all the way up.
3. We wanted to save weight to go fast.
Some other points: Single or double ropes have no bearing on the method whatsoever. There is a master point (between each of the loop) that you can use. If you are not comfortable clipping above the knot then just tie a butterfly knot below and use that as a new master point. Problem solves. The point about sheath melting from an anchor point failure, I think, is valid for factor 2 fall.
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josher
Oct 22, 2002, 6:19 PM
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Climbing Mag has a how-to using a double boline. They havent updated there site, so sorry , no link. Looked like a quick and easy knot
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tradguy
Oct 22, 2002, 10:09 PM
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I'm not 100% sure if this is the same knot Zac is talking about, but go to the bottom of this page:
http://www.utas.edu.au/docs/climbing_club/TUCC/knots/figure8.html
I use this alot when I'm on a route that has a 2 bolt belay anchor - particularly if I want to be more than the length of my daisy chain away from said anchor. The directional figure 8 shown on that same link can be tied just below the main knot, in the end running down to your partner, and you can throw a reverso on it for a quick, easy, auto-locking belay that you could escape from if necessary. (just untie the rope from your harness)
I'm going to be somewhere in the southwest (AZ, or So Cal) over Christmas time, so if I happen to run into you Zac, I can show you what I'm talking about.
As far as benefits - it's fast, easy, requires less extra gear, and allows you to adjust your belay position relative to the anchors for greater distance. For drawbacks - it uses more rope than other options, so if you just finished a 160 ft pitch on a 50 m rope, you're probably not going to be able to use it.
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tradklime
Oct 22, 2002, 10:36 PM
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There is another version of this knot that I believe John Long describes in one of his books. I like it better than the one described in the link above because you finish the figure eight and it can equalize 2 or 3 points.
I'll do my best to describe, start with a loosely tied figure 8 on a bite. Take the loop over the top of the knot and thread it through the last part of the knot again. Do not pull it tight, clip into the loop and one of the strands on the other side of the knot. You can clip into both of the strands for three anchor points, however do not clip into the two strands together for the same anchor point because if the anchor for the main loop fails you are no longer really clipped into the knot.
Confused , get the book. A picture is worth a thousand words.
[ This Message was edited by: tradklime on 2002-10-22 15:36 ]
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pbcowboy77
Oct 23, 2002, 6:17 AM
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Thanks for the info guys. The book I found it in is "Advanced Rock Climbing" by John Long. For me it was not worth buying, but I did find this knot in it. Iguess I'd better try the knot, it's worth $14.95 plus tax
Just joking... well thanks again, and if theres anymore info keep it comming.
-Zac
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buzyrock
Oct 23, 2002, 6:41 AM
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Is it same as what is called "Bunny loop", coz that knot is also self equalizing and can be tied from fig 8
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tradguy
Oct 23, 2002, 2:18 PM
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I have heard the knot I was referring to (pictured in the link above) sometimes called "bunny ears". It isn't truly "self-equalizing" though, so I'm not sure it's the same thing you guys are talking about. It is very easy to equalize the knot manually, though, even after you've clipped the bolts/gear. The benefit is that if one of your anchors blows, you don't have to worry about shock loading the rest of the anchor, or about sliding rope friction damaging the rope as was described by someone else above.
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orangekyak
Oct 23, 2002, 3:28 PM
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I think I'm missing something here. I'm familiar with the knot but not its utility for making an anchor. And the vastly different opinions in the thread aren't helping my understanding. Could someone please direct me to an online source for more info on using this for anchors? Or at least clarify this thread?
Maybe it is clear and I'm just a schmuck (setting myself up...).
Jeremy
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knotrocket
Oct 23, 2002, 5:42 PM
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I believe we are all talking about a Double loop Fig. 8, or I've also heard it called a Canadian Eight. As an anchor knot, two options exist: 1. Making your loops equal and running one to each of your anchors. This will not be self-equalizing, it will be a load-sharing anchor with two legs.
2. This will be harder to explain - Make one of your loops bigger (how big depends on the distance between anchor points) and run only that loop to all of your anchor points. Now, IN BETWEEN each anchor point clip a crab to the rope that forms the big loop and then clip THE SAME CRAB to the SMALLER loop. The trick is getting the BIG loop to be the right size, because you can't just tie it as big as you want. Contrary to someone's post above, if an anchor point fails, you will fall the distance of the slack created in the big loop. If the big loop is tied TOO BIG, this could be enough to blow your remaining anchors. When tied in this fashion, the knot is in theory self-equalizing...
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tradguy
Oct 23, 2002, 5:48 PM
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If you didn't see my post above, click THIS LINK and look at the last picture at the bottom of the page. Now imagine it turned over 180 degrees, with each of the loops clipped into one bolt of a 2-bolt anchor, one of the strands coming out of the other end of the knot tied into your harness, and the other strand going down to your second. Basically, you are tying this knot in the climbing rope to anchor yourself to the belay station, and then you can either tie another knot (directional figure 8 from afore mentioned web page) in the strand going down to your second, and use that as the belay point (with a reverso) or the re-direct point (to an ATC on your harness) for belaying, OR you can clip a locking biner through both "bunny ear" loops above the figure 8, and use that similarly for belaying.
Does that make any more sense? I'm trying, really I am. If I had a digital camera, I would set this all up, take a picture, and post it, but alas, I don't.
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knotrocket
Oct 23, 2002, 6:48 PM
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when used like tradguy is explaining, as a tie-in point for you as a belayer, I wouldn't think it necessary to use it as an SE anchor system, because you won't be moving around a great deal. That also will eliminate much of the shock load concern in the event of a failure at the bolt/pro point.
Also, when using this knot or any anchor system, try to keep all of your system within a 90 deg. angle or so. As you approach 120 deg., the load on each anchor nears the actual weight on the rope. More than 120, it will be more than the actual load. So lengthen the confluence of your slings/webbing/rope until the angle is right. But with SE anchors, remember that the longer the "legs" are, the farther the fall when one fails...
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tradklime
Oct 23, 2002, 8:28 PM
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The knot I tried to explain (and the one that I believe pbcowboy77 was referencing) is used in the same way as the knot that tradguy explained. However, it is self equalizing and can be attached to 3 points (differently than knotrocket described). It does have the problem that in the event of an anchor failure there would be a shock load to the system and nylon rubbing on nylon as it adjusted.
I'll try to find a photo or something to post. As I said before, it really is only beneficial when climbing on a single rope and anchoring to 2 or 3 bolts.
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knotrocket
Oct 23, 2002, 8:45 PM
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If it is different than what I described, it'll be new to me, as I haven't heard of a knot in the Fig. 8 family that is self-equalizing at the knot itself. But I'm all about learning new stuff...
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rck_climber
Oct 23, 2002, 9:13 PM
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Perhaps rrrADAM will jump in to help on this one, as the only time I've ever seen it employed was by him when we climbed together at the SLC gathering on top of Satan's Corner.
It is distinctly different than what I've seen in that link and as described in the rest of the posts here.
It's similar to an equalizing sliding X if memory serves, but can't remember the ugly details of it all.
Will PM him in hopes he can elaborate on his previous answer.
Mick
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slcliffdiver
Oct 23, 2002, 10:28 PM
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tradklime has the right knot though it scares me a bit for hard hits on the anchor. 3 loops might self equalize a bit with a fall 2 will (less friction than with 3) but I don't like the potential for extention and nylon over nylon equilization (rubbing) and a couple of other minor quirks.
I generaly prefer the double loop figure 8 that tradguy posted for 2 points or bowline on a bite for 2 or 3 points depending on the setup. There are a couple of tricks to adjusting a bowline on a bite quickly otherwise it's a pain to equalize maybe that's why I don't here about it much anymore. Hopefully I just didn't miss a memo about there being problems with it. But mostly I'm in love with cordelettes and webolettes.
The equalizing 8 is fast but with the friction in adjusting it I'm guessing I'd be just as fast with cordelettes most of the time but options are good and I'm glad it's in my bag of tricks.
Peace
David
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pbcowboy77
Oct 23, 2002, 10:37 PM
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The knot I was talking about has three loops but you can use 2, the knot tradguy only has two. I don't know if that helps.
-zac
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slcliffdiver
Oct 23, 2002, 10:49 PM
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Right tradklimers knot has 3 loops can colapse to 2 tradguys has 2 but isn't truely self equalizing a good thing in my book. I don't particularly want a rope equalizing over itself (nylon over nylon).
tradklimers is the knot I learned as the equalizing 8, not tradguys his is the double loop 8. Useful for equalizing (between 2 points) but not self equaling. Confusing?
[ This Message was edited by: slcliffdiver on 2002-10-23 15:55 ]
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knotrocket
Oct 23, 2002, 10:57 PM
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EDIT: I just saw your edit cliffdiver, so this ISN'T the knot in the link, the doub. loop fig. 8? One of you guys surely has a digital cam.?!?! Where's our visual aid?
Maybe I'm wrong (not entirely outside the realm of possibility), but I think we might be experiencing some semantic difficulty. The actual KNOT itself, the double-loop-fig-of-8 IS NOT in and of itself a self-equalizing knot. It can be used to create a self-equalizing anchor system. If everyone is using the knot at the bottom of I believe tradguy's link, this is the knot I'm referring to. You can only use this knot to create said system by tying TWO loops of vastly different size. How many "legs" you create is irrelevant. You can add legs ad infinitum, it is only a function of how many anchor points you have, but with increased # of points comes an increase in the friction of the rope against all the crabs. This will make it harder for the system to equalize the load without someone helping it along.
There has been talk of nylon-nylon friction. Where? Using that knot (2-loop fig 8, with diff size loops) there won't be any! No gross movement of rope will occur inside the knot.
Again, if I am wrong, someone please tell me. I dig knots and anchors and that type bidness, so if there is some pimp new way to do things I'd like to know it, for my mental toolkit.
[ This Message was edited by: knotrocket on 2002-10-23 16:04 ]
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slcliffdiver
Oct 23, 2002, 11:09 PM
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Do I write horribly? I agree tradguys knot no nylon over nylon friction, tradklimers potential nylon over nylon friction when it self equalizes. Maybe it's because the names are similar, tradguy, tradclimber one of you want to change names
Sorry no digi cam. But think really simple (hard to desribe though). I'll try a slightly different take on tradklimes discription to see if that helps. I'm writting this so you can see it equalizes by sliding over the top part, I'd really wait at least for a pic before trying it for real going the wrong way and clipping the wrong loops could be very, very bad.
Tie a figure eight on a bite loosly, leave a long loop coming out of the figure 8, take the end of the loop and shove it through the hole in the eight it last came out of. Don't double back go through the hole the opposite direction as for the first part of the double loop 8. If you pull on the loop all the way and the 8 dissolves you went the wrong way. The loops you clip are the loop pulled through the hole and one or two of the section of that loop still on the other side of the hole.
That sounds aweful even to me but it's the best I can do. Think of the simplist thing you can do with the loop going through the main knot.
Peace
David
[ This Message was edited by: slcliffdiver on 2002-10-23 17:06 ]
[ This Message was edited by: slcliffdiver on 2002-10-23 17:14 ]
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knotrocket
Oct 24, 2002, 2:19 AM
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Believe it or not, that is a fairly good explanation. I can picture the knot pretty well. I'm gonna play around with it tomorrow. 'PRECIATE IT!
Zach
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