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mrswix


Feb 25, 2009, 12:25 PM
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double figure eight for anchor?
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whats up everyone...just a quick question...

would a double figure 8 work as a setup for practicing jugging?

so basically we would tie the double figure 8, and each "ear" would go to a biner to a bolt in the gym...thanks for any help


vegastradguy


Feb 25, 2009, 12:27 PM
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Re: [mrswix] double figure eight for anchor? [In reply to]
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use it all the time. bomber.


rockforlife


Feb 25, 2009, 12:29 PM
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Re: [vegastradguy] double figure eight for anchor? [In reply to]
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vegastradguy wrote:
use it all the time. bomber.

2nd

People use this to set gym routes also.


mrswix


Feb 25, 2009, 2:47 PM
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Re: [rockforlife] double figure eight for anchor? [In reply to]
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easy enough...thanks guys


johnwesely


Feb 25, 2009, 2:50 PM
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Re: [mrswix] double figure eight for anchor? [In reply to]
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I am trying to envision what you are talking about, and it's coming up blank. Could you clarify?


acorneau


Feb 25, 2009, 3:01 PM
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Re: [johnwesely] double figure eight for anchor? [In reply to]
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johnwesely wrote:
I am trying to envision what you are talking about, and it's coming up blank. Could you clarify?

Double figure 8 (super 8) tied in one end of the rope. The two bights are clipped to two bolts near the top of the wall. Jugging commences.

(It took me a minute to figure out what he/she was asking as well.)


johnwesely


Feb 25, 2009, 3:15 PM
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acorneau wrote:
johnwesely wrote:
I am trying to envision what you are talking about, and it's coming up blank. Could you clarify?

Double figure 8 (super 8) tied in one end of the rope. The two bights are clipped to two bolts near the top of the wall. Jugging commences.

(It took me a minute to figure out what he/she was asking as well.)

Ok, that makes sense. I thought he wanted to tie a figure eight on a bight on the quickdraw at every bolt, and then jugging and cleaning the line.


patmay81


Feb 25, 2009, 3:23 PM
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Re: [mrswix] double figure eight for anchor? [In reply to]
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I usually use a standard 8 on a bite with two qd's with long bones. just make sure the gates are opposing, or use lockers


altelis


Feb 25, 2009, 4:12 PM
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Re: [patmay81] double figure eight for anchor? [In reply to]
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patmay, the advantages of the dbl fig 8 are:
1) don't need to worry about gates
2) don't need to worry about the length of the draws
3) don't need to worry about if the line you want the rope hanging from isn't exactly in between the two bolts- you can change this by shortening one arm and not the other
4) don't need to worry about if the bolts are too far apart horizontally to give a nice tight angle
5) don't even need to worry about bolts being horizontal. hell, if there isn't a bolted top anchor you could theoretically combine the two last bolts into a vertically arranged anchor, they'd be a little far apart, but who cares? people tend to only think of horizontally spaced anchors, but in terms of angles a horizontally arranged anchor is far superior.


not to say that your way is bad; hell i use that set up all the time. just pointing some crap out, trying to make this as complicated as possible.


jeepnphreak


Feb 26, 2009, 10:18 AM
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Re: [mrswix] double figure eight for anchor? [In reply to]
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mrswix wrote:
whats up everyone...just a quick question...

would a double figure 8 work as a setup for practicing jugging?

so basically we would tie the double figure 8, and each "ear" would go to a biner to a bolt in the gym...thanks for any help


Yep that way works just fine, I have use bouble 8 several times and have never had a problem.


kachoong


Mar 1, 2009, 4:45 PM
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Are you guys talking about rabbit-ears?




uni_jim


Mar 1, 2009, 4:54 PM
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Re: [kachoong] double figure eight for anchor? [In reply to]
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yes.


blueeyedclimber


Mar 2, 2009, 11:05 AM
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Re: [kachoong] double figure eight for anchor? [In reply to]
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kachoong wrote:
Are you guys talking about rabbit-ears?

[image]http://www.chockstone.org/TechTips/BunnyEar6l.JPG[/image]

NO. A double figure 8 is two independent figure 8's on a bight. THat is a dog-ear (or if you prefer a rabbit ear) figure eight. Two independent figure 8's are redundant whereas a dog ear is not. BUt the dog ear is easier to equalize.

Josh


kachoong


Mar 2, 2009, 11:07 AM
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Re: [blueeyedclimber] double figure eight for anchor? [In reply to]
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blueeyedclimber wrote:
kachoong wrote:
Are you guys talking about rabbit-ears?

[image]http://www.chockstone.org/TechTips/BunnyEar6l.JPG[/image]

NO. A double figure 8 is two independent figure 8's on a bight. THat is a dog-ear (or if you prefer a rabbit ear) figure eight. Two independent figure 8's are redundant whereas a dog ear is not. BUt the dog ear is easier to equalize.

Josh

That's what I thought, but was confoozed by the dialogue! Being from Aus I think anti-clockwise.

edit: Hang on... no, I do believe a bunny-ears is what's being discussed.


(This post was edited by kachoong on Mar 2, 2009, 11:29 AM)


desertwanderer81


Mar 2, 2009, 11:12 AM
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Re: [johnwesely] double figure eight for anchor? [In reply to]
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johnwesely wrote:
acorneau wrote:
johnwesely wrote:
I am trying to envision what you are talking about, and it's coming up blank. Could you clarify?

Double figure 8 (super 8) tied in one end of the rope. The two bights are clipped to two bolts near the top of the wall. Jugging commences.

(It took me a minute to figure out what he/she was asking as well.)

Ok, that makes sense. I thought he wanted to tie a figure eight on a bight on the quickdraw at every bolt, and then jugging and cleaning the line.

I had the same mental image.


summerprophet


Mar 2, 2009, 11:45 AM
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Re: [blueeyedclimber] double figure eight for anchor? [In reply to]
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blueeyedclimber wrote:
NO. A double figure 8 is two independent figure 8's on a bight. THat is a dog-ear (or if you prefer a rabbit ear) figure eight. Two independent figure 8's are redundant whereas a dog ear is not. BUt the dog ear is easier to equalize.
Josh

Firstly, I will openly admit, I have no idea how you create two independent figure eights on a single bight.

HOWEVER, both the bunny ears and this "Double figure 8 knot of yours have NO redundancy. Look where the rope comes into the knot..... Oh yes a single rope...... thus no redundancy.

Incidently, I searched Double figure 8 knot and nothing obvious was found. Care to clarify what this knot is?


acorneau


Mar 2, 2009, 11:51 AM
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Re: [summerprophet] double figure eight for anchor? [In reply to]
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summerprophet wrote:
HOWEVER, both the bunny ears and this "Double figure 8 knot of yours have NO redundancy. Look where the rope comes into the knot..... Oh yes a single rope...... thus no redundancy.

If you do a little research you'll find that every time this knot is tested the rope will break outside the knot, never inside. Besides, redundancy is only needed for the connections to the rock (bolts, pro) and not for the rope itself.


patmay81


Mar 2, 2009, 11:58 AM
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Re: [altelis] double figure eight for anchor? [In reply to]
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altelis wrote:
patmay, the advantages of the dbl fig 8 are:
1) don't need to worry about gates
2) don't need to worry about the length of the draws
3) don't need to worry about if the line you want the rope hanging from isn't exactly in between the two bolts- you can change this by shortening one arm and not the other
4) don't need to worry about if the bolts are too far apart horizontally to give a nice tight angle
5) don't even need to worry about bolts being horizontal. hell, if there isn't a bolted top anchor you could theoretically combine the two last bolts into a vertically arranged anchor, they'd be a little far apart, but who cares? people tend to only think of horizontally spaced anchors, but in terms of angles a horizontally arranged anchor is far superior.


not to say that your way is bad; hell i use that set up all the time. just pointing some crap out, trying to make this as complicated as possible.
yes, I understand all the possible reason for using a double 8. But since we are talking about bolted anchors 99 times out of 100 its easier, faster and in many ways safer to slap a couple of draws or slings up in order to fix a rope.


summerprophet


Mar 2, 2009, 11:58 AM
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Ummmm, I think you just agreed with me.

As far as research goes...... In Theory a knot will always break within the knot, at the tightest bend. In Practice, the knot typically breaks at the entry to the knot, or at the connection to the testing apparatus. The assumption here is that the friction of the strands reducing the directional forces to the knot.

The point I was trying to make, was just that redundancy does not aply to your main line (be it lead line or jugging line).


blueeyedclimber


Mar 2, 2009, 12:22 PM
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Re: [kachoong] double figure eight for anchor? [In reply to]
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Well, then, they're confusing me and not being very clear. Either way, what i said about each is absolutely correct.

Josh


blueeyedclimber


Mar 2, 2009, 12:41 PM
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Re: [summerprophet] double figure eight for anchor? [In reply to]
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summerprophet wrote:
blueeyedclimber wrote:
NO. A double figure 8 is two independent figure 8's on a bight. THat is a dog-ear (or if you prefer a rabbit ear) figure eight. Two independent figure 8's are redundant whereas a dog ear is not. BUt the dog ear is easier to equalize.
Josh

Firstly, I will openly admit, I have no idea how you create two independent figure eights on a single bight.

HOWEVER, both the bunny ears and this "Double figure 8 knot of yours have NO redundancy. Look where the rope comes into the knot..... Oh yes a single rope...... thus no redundancy.

Incidently, I searched Double figure 8 knot and nothing obvious was found. Care to clarify what this knot is?

Sorry, I didn't mean on a single bight. It's actually two separate bights side by side. This is commonly used for a power point when using static line to set up a toprope. It is redundant in this setup because if any single line gets cut, then you are still good. Whereas, if the dog ear figure gets cut in this same setup, you compromise the entire anchor.

That said, the dog-eared figure eight is very useful to connect yourself to a two bolt anchor.

Josh


summerprophet


Mar 2, 2009, 12:48 PM
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Re: [blueeyedclimber] double figure eight for anchor? [In reply to]
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Ahhhh, ,now I understand where you are coming from. I did teach that method while I was guiding.

What you are refering to cannot apply to the OP's question, where he is using two bolts at a gym, rather than a second rope to a node point.

I think the confusion is resulting from the fact that the method you describe involves a second rope to create the anchor (threfore everything should be redundant) whereas a bunny ear / dog-ear involves using the main line which CANNOT (and doesn't need to) be redundant using single rope techniques.

Oh, and to avoid confusion in the future, you are describing doubled figure eightS, rather than A double figure of eight


(This post was edited by summerprophet on Mar 2, 2009, 12:50 PM)


ski.ninja


Mar 2, 2009, 1:12 PM
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Re: [summerprophet] double figure eight for anchor? [In reply to]
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From Rock Climbing Anchors by Craig Luebben, p. 220.

In reply to:
The double loop figure eight [bunny/rabbit/dog ears] creates two secure loops that can be clipped to two different anchors. It is not truly redundant, because if one loop severs, the other loop may slip through the knot, causing anchor failure. However, the rope is rarely redundant anyway.

Spot on. Not redundant, but still useful. I know ACMG guides who use this setup regularly to establish anchors, or tie in to belay stations.

One more note for real world usage. If dynamic rope is used and the loops are of unequal length then equalization will not occur in the event of a fall, as the rope will not stretch the same length on each loop. The shorter loop would take more force than the longer loop. Just something to keep in mind.


blueeyedclimber


Mar 2, 2009, 2:33 PM
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Re: [summerprophet] double figure eight for anchor? [In reply to]
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summerprophet wrote:
Ahhhh, ,now I understand where you are coming from. I did teach that method while I was guiding.

What you are refering to cannot apply to the OP's question, where he is using two bolts at a gym, rather than a second rope to a node point.

I think the confusion is resulting from the fact that the method you describe involves a second rope to create the anchor (threfore everything should be redundant) whereas a bunny ear / dog-ear involves using the main line which CANNOT (and doesn't need to) be redundant using single rope techniques.

Oh, and to avoid confusion in the future, you are describing doubled figure eightS, rather than A double figure of eight

Second rope? No. One rope, two bights side by side. This is one of the methods that the AMGA teaches to create a power point with. Now, this is a little off topic, but you can also hang a rope using this method, which I believe the op was about.

Josh


summerprophet


Mar 2, 2009, 3:13 PM
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Re: [blueeyedclimber] double figure eight for anchor? [In reply to]
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Sigh......

I give up trying to explain this.

The OP got his answer long ago.

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