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Figure 8 vs Double Bowline
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By CareBear
From SLC, UT
Dec 11, 2012

"I have whitnessed "Drop Test" and if you keep dropping the weight enuf times, the rope breaks at the knot. It gets pinched down and that is where the rope eats it...... then you eat it."

Guy not that I doubt you, but I just never heard of this. Can you provide a link with this drop test?


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By bearbreeder
Dec 11, 2012

on my gym gumbie days, ill take a few 20 foot whippers per session ... il start with one right off the warmup in fact to get it out of the system

on my sport days ... ill usually do the same at my limit ... often itll be 5-10 falls of varying length

on my trad days, of the fall is clean and the gear is good, ill take the fall ... several times a session if youre doing stuff at your limit

sure theres been a few times where the fig 8 takes a bit more work to undo ... but if you tie it and undo it properly its not that hard ... its not like yr in any rush when cragging routes at your limit anyways

if a lazy weak azzed climber like me can undo it fine ... i dont know how all of you hardcore MP climbing experts cant ...

;)


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By 20 kN
From Hawaii
Dec 11, 2012

Guy Keesee wrote:
That knot, absorbs almost 40% of the fall forces. I have whitnessed "Drop Test" and if you keep dropping the weight enuf times, the rope breaks at the knot. It gets pinched down and that is where the rope eats it...... then you eat it.

This is completely false. UIAA rope tests almost always fail at the point where the rope runs over the jig in the middle of the tower. Furthermore, the knot does not reduce the impact force of the fall by 40%, not even remotely close. In most climbing scenarios the knot does not do much of anything towards the impact force on the top piece, especially not on long low fall factor falls. In high fall factor scenarios with static belays and steel weights, the knot will play a small role, but 40%, absolutely not.


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By Ed Wright
Dec 11, 2012
Magic Ed

Guy H. wrote:
I am paranoid about checking my knot and my partner's knot these days. I watched a ground fall in Eldo when some guy didn't finish his figure 8. I have also saved one of my partner's lives when I noticed their figure-8 wasn't finished when they were about 10ft off the ground. The biggest thing going for the figure 8 is that it is easily inspected. I have never had major issues with untying one, but I normally don't take big whippers.


Actually, the last pass through on a figure 8 is redundant--the knot will hold just fine without it--I know from personal experience.


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By Guy Keesee
From Moorpark, CA
Dec 12, 2012
Big Boulder, just a bit downhill from Temple of Kali. Alabama Hills, CA.

Guy not that I doubt you, but I just never heard of this. Can you provide a link with this drop test?

The test I watched, were before VIDEOS.

The rope was not running over a JIB, what ever the heck that is.

Just down a small vertical cliff.

20kn... you can argue 40%... 30% .... 20%... 10% .... whatever...

I know what works for me.

A few years back, a whole party decked from pitch 4 at Taquitz.

The anchor blew when the 2nd fell on a slab with some slack in the system.

To make a story short.... the 2nd was the leader for most of the climb... he had taken several falls .... during the post mortum the one thing they discouvered was this. His figure eight was to tight to uintie, even with vice grips....

Think about that for a second...


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By Buff Johnson
Dec 12, 2012
smiley face

Yes at some point you can fail any equipment, but really, climbing whippers on a dynamic made today are so small on the scale relative to actually failing the rope, or being the problem of any climbing accident for that matter.


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By Jon Marek
From SLC
Dec 12, 2012
gossamer

It doesn't matter what tie-in knot you use. Almost every accident cited here has little to do with the knot, and alot to do with people not paying attention to their tie-in. The worst accident I have seen of this sort happened when an older climber at the crag tied his fig-8 into a leg-loop strap. He only fell from 10ft or so but the improper tie-in flipped him and then ripped.

Also, YER ALL GONNA DIE!!!


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By Brassmonkey
Dec 12, 2012
Brass monkey

Guy Keesee wrote:
Guy not that I doubt you, but I just never heard of this. Can you provide a link with this drop test? The test I watched, were before VIDEOS. The rope was not running over a JIB, what ever the heck that is. Just down a small vertical cliff. 20kn... you can argue 40%... 30% .... 20%... 10% .... whatever... I know what works for me. A few years back, a whole party decked from pitch 4 at Taquitz. The anchor blew when the 2nd fell on a slab with some slack in the system. To make a story short.... the 2nd was the leader for most of the climb... he had taken several falls .... during the post mortum the one thing they discouvered was this. His figure eight was to tight to uintie, even with vice grips.... Think about that for a second...



People like you are the reason why fallacies and wives-tales keep getting passed around..and some get hurt because of it. Straighten out your facts before you spray them around.

School yourself on the actual UIAA test and you will know what the thing he describes as a jib is. You'll also learn a lot along the way.

I am thinking about it for a few seconds...minutes. And it still makes no sense. Are you telling us to build better anchors? Or were these those damn "Vertical Limit" exploding bolts again. I hate those damn things. Try again.

PS. The bowline rocks!


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By Cale Hoopes
From Sammamish, WA
Dec 12, 2012
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LOL. The exploding bolts. I thought about those exact things here.


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By Rob Davis
From Brooklyn, NY
Dec 12, 2012

Guy Keesee wrote:
Guy not that I doubt you, but I just never heard of this. Can you provide a link with this drop test? The test I watched, were before VIDEOS. The rope was not running over a JIB, what ever the heck that is. Just down a small vertical cliff. 20kn... you can argue 40%... 30% .... 20%... 10% .... whatever... I know what works for me. A few years back, a whole party decked from pitch 4 at Taquitz. The anchor blew when the 2nd fell on a slab with some slack in the system. To make a story short.... the 2nd was the leader for most of the climb... he had taken several falls .... during the post mortum the one thing they discouvered was this. His figure eight was to tight to uintie, even with vice grips.... Think about that for a second...


I'm not trying to be rude, but if a reason you cite for not using a figure 8 is that it can fail from repeated falls, and then say your only source is a link you can't provide, it's hard for me to take you seriously. Furthermore, if you're talking about a rope failing at 20kn, then you're talking about a rope/knot falling a good bit after the climber has snapped in half. So really, you're talking about hypotheticals that can't be created without a climbing death before the failure.


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By csproul
From Rancho Cordova, CA
Dec 12, 2012
Summit of Wolf's Head with Pingora in the background

Rob Davis wrote:
I'm not trying to be rude, but if a reason you cite for not using a figure 8 is that it can fail from repeated falls, and then say your only source is a link you can't provide, it's hard for me to take you seriously. Furthermore, if you're talking about a rope failing at 20kn, then you're talking about a rope/knot falling a good bit after the climber has snapped in half. So really, you're talking about hypotheticals that can't be created without a climbing death before the failure.

20 kN is a person:
mountainproject.com/u/20-kn//106349691


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By Rob Davis
From Brooklyn, NY
Dec 12, 2012

csproul wrote:


yeah misread. Regardless, I think the argument for knot fail is silly.


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By Guy Keesee
From Moorpark, CA
Dec 12, 2012
Big Boulder, just a bit downhill from Temple of Kali. Alabama Hills, CA.

Wow, you all get riled up pretty easily.

I do not wish to spread wives tales, lies or misinformation.

I don’t know just what the UIAA says or does…

All I am trying to point out is this: I witnessed, on a test set up used to evaluate climbing stuff, many drop tests that resulted in broken Biners, Bolt hangers etc.

The one thing that impressed me the most was the test where they broke a rope. It took many many…. More than 30 or 40 but the rope broke at the knot.

I use a figure 8 cause I think it’s best for ME.

I know when its right and you cant tie it wrong unless you really try.

I do retie it after a hard fall.

You all can use whatever knot you wish, it’s a free country.

And no there are no exploding bolts, that anchor that failed at Taquitz was made of cams.

And it failed….

I feel sorry for the dead climbers, they suffered.

RIP


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By Brassmonkey
Dec 12, 2012
Brass monkey

In a drop test where there is a straight fall onto the rope and not other variables present the rope will eventually fail(per you 30-40 drops of an unknown weight) at the weakest point, aka the knot. Some knots decrease the strength of the rope more than others. More than likely what you witnessed was not the loss of dynamic forces due to the knot being really tight, but rather the rope failing at its weakest point when after repeated (factor 2?) falls on a short length of rope that did not have time to rebound from the falls. Ropes are not indestructible.

Are you referencing this accident:

www.rockclimbing.com/cgi-bin/forum/gforum.cgi?do=post_view_f>>>


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By Guy Keesee
From Moorpark, CA
Dec 12, 2012
Big Boulder, just a bit downhill from Temple of Kali. Alabama Hills, CA.

"Are you referencing this accident:"

Yes, that is the one.


The drop testing I saw, used about 175 lbs as the climber, I was told right where the rope would fail... "right where the knott pinches down"

It was a brutal demo....

And after seeing that: I have no fear of a cord snapping under falling senarios.


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By nicelegs
From Denver
Dec 12, 2012

Guy, I truly don't know what you are saying.

Is it that the accident you mentioned would have been prevented with a different knot?

Or are you saying something else, I sure can't figure it out.


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By Mark E Dixon
From Sprezzatura, Someday
Dec 12, 2012
At the BRC

John Marsella wrote:
You could butter up the holds like Paula Deen butters a turkey and Baumer couldn't fall any more frequently... JK Baumer


Does he butter up the rope too or something?

I'll stick with the brotherhood knot. Keeps the mentally balanced at bay.


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By Guy Keesee
From Moorpark, CA
Dec 12, 2012
Big Boulder, just a bit downhill from Temple of Kali. Alabama Hills, CA.





Guy, I truly don't know what you are saying.

Is it that the accident you mentioned would have been prevented with a different knot?



Who knows... the anchor was put under a servere strain, snatch type force.

Cams do fail when pulled suddenly in this manner. (a known fact)


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By Brassmonkey
Dec 12, 2012
Brass monkey

So let me get this straight, and please believe me that I am not trying to be rude. You witnessed a demo where a rope severed where it essentially was meant to in a completely unrealistic test, then heard of an accident that had nothing whatsoever to do with a knot but rather an anchor failing under a possible factor 2, somewhere baked up the number 40% for the amount of force a figure eight takes in a fall, tried to pass that off here as a real statistic, are then told otherwise by several others who are more knowledgeable but choose to say

Guy Keesee wrote:
20kn... you can argue 40%... 30% .... 20%... 10% .... whatever... I know what works for me.


and then you can't even explain what you are trying to say?

I know who I wont be roping up with.


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By Brassmonkey
Dec 12, 2012
Brass monkey

PS I fear the snatch force as well.


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By 20 kN
From Hawaii
Dec 12, 2012

Guy Keesee wrote:
Guy not that I doubt you, but I just never heard of this. Can you provide a link with this drop test? The test I watched, were before VIDEOS. The rope was not running over a JIB, what ever the heck that is. Just down a small vertical cliff. 20kn... you can argue 40%... 30% .... 20%... 10% .... whatever... I know what works for me. A few years back, a whole party decked from pitch 4 at Taquitz. The anchor blew when the 2nd fell on a slab with some slack in the system. To make a story short.... the 2nd was the leader for most of the climb... he had taken several falls .... during the post mortum the one thing they discouvered was this. His figure eight was to tight to uintie, even with vice grips.... Think about that for a second...






There you go. Those are videos of ropes being tested within UIAA accordance at UIAA approved testing facilities.

As you saw in both of those videos, the rope failed at the jig that simulated a carabiner in the middle of the drop tower. That is pretty much always where the rope fails in a UIAA test, it does not fail at the knot. The rope will fail at the knot if the drop test does not involve the use of a simulated carabiner (the jig,) and the weight is dropped directly onto a straight rope without the rope running through anything. But that is not how ropes are tested because in the real world you are always running the rope through a piece of pro (except in a factor two scenario.)

The way the rope fails in these UIAA testing videos are the basis of why brand new ropes will almost always hold more UIAA replica falls in the real world then they will in a testing facility. See, when the weight is dropped the load is always placed over the exact same point of the rope, right at the jig. This causes severe wear at the loading point which ultimately leads to the rope's failure. The loading point does not change because the "belayer" is a piece of steel clamping down on the rope which does not allow any slippage. Accordingly, the length of the rope always remains the same (minus plastic deformation and permanent elongation) and so the section of rope running through the jig is always the same.

However, if you were to take repeated factor 1.78 falls on a route, you would not load the rope in the exact same point over and over like in the testing facility. Your belayer might give you more slack on one burn, less on another, you may make it one move further on one burn, one less move further on another, and on and on, which means you wont load the same point of the rope on every fall and therefor the wear and damage will occur over different sections of the rope rather than in the exact same section. Furthermore, your belyer is going to get pulled up which also means different sections of the rope will run through the carabiner as opposed to the same section over and over. Those conditions would likely result in the rope holding more UIAA falls than it is rated for, which is why the UIAA testing scenario is an absolute worst case scenario that is very rarely replicated in the real world, even in factor two fall scenarios.


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By Medic741
From Pittsford, New York
Dec 12, 2012
When I was a bum at Frey

Guy can't tell if you're trolling or what... I hope trolling...


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By Guy Keesee
From Moorpark, CA
Dec 12, 2012
Big Boulder, just a bit downhill from Temple of Kali. Alabama Hills, CA.

Medic.... I never TROLL I may make an outragous statement just to get the duscission going, but no trolling.

And to 20 kN.... thanks for the vid. and confirming what I saw was true.

You wrote: "The rope will fail at the knot if the drop test does not involve the use of a simulated carabiner (the jig,) and the weight is dropped directly onto a straight rope without the rope running through anything. But that is not how ropes are tested because in the real world you are always running the rope through a piece of pro (except in a factor two scenario)"


Thank you for that.


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By Antonio Caligiuri
From Pittsburgh, Pennsylvania
Jun 27, 2014
Approaching the anchors on Eclipse (5.6) at Breakneck Rocks in Connellsville, PA.

Can anyone explain to me how this knot would ever come out on a single pitch sport climb, with or without a backup stopper?

EDIT: I really would like a specific explanation if anyone has one, not just being a dick.


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By amarius
Jun 27, 2014

The knot in the YouTube video is "Bowline on a bight", aka "rethreaded bowline"

I've never read of this particular knot inverting, untying, or doing other horrible things


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