Author Topic: Cordage Movement & Melting Damage Risk?!  (Read 3790 times)

roo

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Re: Cordage Movement & Melting Damage Risk?!
« Reply #15 on: February 06, 2018, 12:57:01 AM »
Anyhow, I think there is sufficient information here to put the gnat (noose) quietly to bed. It definitely has its place in the world of knotting but, that place is not as a tie-in to a rock climbers harness.
Huh?  The test results show no ill effect of the Gnat Hitch on webbing.

If you follow your blind prejudice to its logical end, you're going to have to put your Grim Reaper doodle on every knot, since the level of standing part motion, and thus nylon-on-nylon motion, is virtually equivalent.
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agent_smith

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Re: Cordage Movement & Melting Damage Risk?!
« Reply #16 on: February 06, 2018, 01:03:07 AM »
roo

Could you please visit this website: http://www.darwinawards.com/

If you follow your blind logic to its bitter end - and tie-in to a rock climbing harness with a gnat (noose) - I think we will find your name posted on Darwin Awards.

I personally would not like to see you remove yourself from Earths gene pool.

roo

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Re: Cordage Movement & Melting Damage Risk?!
« Reply #17 on: February 06, 2018, 01:05:35 AM »
roo

Could you please visit this website: http://www.darwinawards.com/

If you follow your blind logic to its bitter end - and tie-in to a rock climbing harness with a gnat (noose) - I think we will find your name posted on Darwin Awards.

I personally would not like to see you remove yourself from Earths gene pool.
Reported to moderators.
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agent_smith

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Re: Cordage Movement & Melting Damage Risk?!
« Reply #18 on: February 06, 2018, 01:08:29 AM »
Quote
Reported to moderators.

Thank you.

Like I said, it was a genuine feeling of remorse. I do not wish to see you injured of killed. That is a fact.
Its not an insult. Its expressed as a concern.

agent_smith

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Re: Cordage Movement & Melting Damage Risk?!
« Reply #19 on: February 06, 2018, 05:07:20 AM »
Quote
Another tie-in-structure idea :
1) clove hitch to tie-in thread (well, if all so darn skinny!);

2) take hitch tail up and put in a bowline,

3) then bring eye-knot tail down to tuck *through*
the clove h. --i.e., run it along tie-in "thread",
which increased hitch-to bulk-- ; and finally

4) take tail --which needed to be long enough-- up
to tuck through the bowline's nipping loop,
giving a 3rd diameter and further security.

The eyeknot should be abutting the hitch,
and thereby giving what I'll call "security by crowding"

Trying to decipher and tie this suggested composite knot....

A close analog appears to be illustrated at #1853 (but there needs to be #1245 clove hitch formed around the harness tie-in point) - just trying to establish a mental image.
With all the routing, and re-routing of the tail + padding to the clove hitch, I think this will be hard to 'guesstimate' the correct length of rope to complete this composite knot.
Sorry - I just don't see this suggestion as ever becoming a popular tie-in knot.

And the direct clove hitch interface to the harness tie-in loop with added padding - while not acting as a noose - it is difficult to understand if any net movement would occur at the moment of impact in a free-fall (would need to be tested and verified).

Dan_Lehman

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Re: Cordage Movement & Melting Damage Risk?!
« Reply #20 on: February 06, 2018, 11:54:30 PM »
Trying to decipher and tie this suggested composite knot....
Just Do It!
The simple scheme actually should need no particular
instructions :: connect to harness w/clove h.
(for reasons indicated); leave long enough tail so
to be able to put in a bowline
and then thread tail back through hitch,
and ... .
Frankly, as I write this, the main point is having
the eye knot snug to the hitch AND the hitch's
tail of course used in the eye (done in tying the
eye knot).
At this point --never mind the threading through
hitch, and then further, through eye knot--,
there should be that security-via-abutting aspect.

BUT, the tucking at least in the first case does
add a factor; then the last tucking added that
"3rd diameter" (but one could skip the troublesome
tucking and do this directly).

Note that in some earlier and more complicated
formulation, I had a strangle gripping the eye's tail,
being tyed first in hitch tail,
so to be a possible stopper if ... (incredible loosening occurred).
That's admittedly going far in defence for unlikely scenario.
But the binder couldn't untie/loosen so long as it was between
the hitch & eye --more of the "abutting" factor.


.:.  So, in some simpler ways, one can get hitch-wise
load distribution and maybe tail-nipping.

(And I wonder at the repeated rope movement of the
turNip of a repeatedly fallen upon (working some "sport
route") bowline?!  (Consider that with all of the
possible tucking in the most-tucked case, there'd be
3 strands in the turNip, and the outgoing eye leg
connecting eye knot to hitch :: what are the tensions
on those?  --I'm thinking that the outgoing eye leg
gets well less than usual, unless the SPart draws
heavily around into it?!  100% going to 4x25% ?!


--dl*
====

Bipbip

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Re: Cordage Movement & Melting Damage Risk?!
« Reply #21 on: February 07, 2018, 01:32:20 AM »
Not a full time climber, but here is my opinion on the matter : rock climbers tend to regard new techniques with suspicion. Though I sometimes found this annoying I think it comes from a place of wise cautiousness : who would like to discover an unexpected mode of failure at their expense when failure could mean a long drop to the ground ?

Tying in to a climbing harness whith a noose seems a rather silly idea at first, but things are often more complex than our understanding of them, so maybe I'm wrong and some generation of climbers to come will adopt the gnat hitch as their standard tie in knot and fig.8 will be a thing of old timers, but that's not going to happen without solid proof of its security. Exactly for that same reason that things can really be different than what we expect them to be, it is unwise to advocate such a change in practise on mere guesses. We may not know for sure that a fixed loop is safer than a noose, but neither do we know that a noose is safe at all for this purpose ! On the contrary, though a fixed loop may not be the safest possible method of tying to a harness, we have ample evidence that it is safe enough. This alone should keep us from tying to a climbing harness with a noose and from advising anyone to do so.

What it doesn't prevent us to do, however, is discussing the pro and cons of this method, it's not likely to change the way climbers are tying themselves but it can bring a better understanding of knots and their application.

agent_smith

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Re: Cordage Movement & Melting Damage Risk?!
« Reply #22 on: February 07, 2018, 01:44:10 AM »
Quote
Just Do It!
Sounds like an slogan for Nike   :o

Ok - I did just did it.
I will be honest and state that this 'composite' structure is something that will never develop legs and gain popularity in the climbing community. People will just stick with a fixed eye knot such as #1047 F8 eye knot (or a secure Bowline). Its too fiddly and not as quick and convenient as standard tie-in eye knots.

If your main intent is to add dual eyes to the harness tie-in point - why not just experiment with a derivative of #1072 Portuguese Bowline or a derivative of #1080 Bowline on-a-bight (where no back-flip maneuver is performed) - I'll play around with these ideas and maybe snap a photo if it looks promising.

agent_smith

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Re: Cordage Movement & Melting Damage Risk?!
« Reply #23 on: February 07, 2018, 02:10:03 AM »
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What it doesn't prevent us to do, however, is discussing the pro and cons of this method

Hello Bipbip, I agree about the notion that 'discussing' concepts is a good thing.
My disagreement with roo is that he made a declaration that a noose is safe to use as a tie-in to a rock climbing harness for climbing purposes. This is where I draw the line, because it progresses beyond discussion and constitutes advice.
The gnat structure acts like a noose - and we have ample empirical evidence (see my previous post about Dan Osman) that nylon sawing across nylon in a free-fall event is not good. I also posted a photo of a prusik hitch that disintegrated on a factor 1 fall (which further shows the danger of nylon-on-nylon during fall event).

Quote
though a fixed loop may not be the safest possible method of tying to a harness, we have ample evidence that it is safe enough. This alone should keep us from tying to a climbing harness with a noose and from advising anyone to do so.
Indeed. We have empirical evidence that a fixed eye knot has worked since the 1950's (Hillary used a Bowline to climb Everest in the 1950's and we can see photos of him using said Bowline). Every day around the world, hundreds of people are climbing outdoors using fixed eye knots as a tie-in.
We are not seeing mass deaths from mass failures of the fixed eye knots.
Harness manufacturers know this too - and thats why they only recommend tying-in with a fixed eye knot.

In my view, roo is taking a legal risk by openly giving advice that a noose is a safe method of tying a dynamic rope to a rock climbing harness. Although I think it would be difficult for any plaintiff to sue him - since the plaintiff doesn't know his real name or address (although IGKT could be subpoenaed/compelled to reveal these details in a court case). Furthermore, the 'plaintiff' would likely be killed or in coma from a serious fall - so it would be the family that would sue in their childs name. Litigants in a court would also have to prove that roo had a 'proximate' relationship with the plaintiff - and that his words constituted negligent advice (I am not sure if there are any existing cases which set a precedent).

roo has claimed that he has tested his gnat (noose) - and openly declares that it 'passes' his test regime. I note that his test results have not been peer reviewed nor have others attempted to reproduce his test results under strict lab conditions.

roo also has not submitted his findings to harness manufacturers to solicit their views/opinions (which act to contradict their advice and instructions). I would suggest that rock climbing harness manufacturers would not support roo's advice to use a tie-in knot that acts like a noose.
« Last Edit: February 07, 2018, 02:25:02 AM by agent_smith »

roo

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Re: Cordage Movement & Melting Damage Risk?!
« Reply #24 on: February 07, 2018, 02:44:48 AM »
We may not know for sure that a fixed loop is safer than a noose, but neither do we know that a noose is safe at all for this purpose
The evidence says otherwise.   The test data shows that the Gnat Hitch does not cause ill effect on the webbing, and that it is amply secure, and its security exceeds many common means of attachment.  Its use is thus actually safer.

The science of safety cannot advance if we close our eyes to the evidence.  Think of all the bowline variants that agent_smith advances in his paper.  With even less evidence of their security and lack of heat damage, he proposes them for life support use.

But the heat damage issue is rather silly.  When the amount of standing part motion is virtually equivalent for a Gnat Hitch or Zeppelin Bend, or some Bowline variant, or a Double Fisherman's Knot, it makes absolutely no sense to chase that lead expecting the rope to melt.

Now, if you want to reproduce the test results, that's perfectly fine.  I always recommend new users to test knots in the conditions and materials that they anticipate, since those conditions may be somewhat unique.  Every user has to decide which knots are the best fit for their purpose.


« Last Edit: February 07, 2018, 04:04:25 AM by roo »
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agent_smith

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Re: Cordage Movement & Melting Damage Risk?!
« Reply #25 on: February 07, 2018, 03:00:46 AM »
Quote
The evidence says otherwise.

With all due respect: Who's evidence?

roo

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Re: Cordage Movement & Melting Damage Risk?!
« Reply #26 on: February 07, 2018, 03:45:01 AM »
Quote
The evidence says otherwise.

With all due respect: Who's evidence?
I'm not stopping you from doing some tests.   If you prove it to yourself, it'll make much greater of an impact than merely reading about it.
« Last Edit: February 07, 2018, 03:46:23 AM by roo »
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agent_smith

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Re: Cordage Movement & Melting Damage Risk?!
« Reply #27 on: February 07, 2018, 03:59:20 AM »
That wasn't an answer to my question.

So I'll ask the question again: "Who's test results are you referring to?"

And to take it a step further:
1. Have these test results been peer reviewed?
2. Have these test results been submitted to rock climbing harness manufacturers for their comment?
3. And to be 100% crystal clear - are you advising to the world at large - that a tie-in knot to a rock climbers harness can be a noose?

And for any experienced rock climbers who may be reading these posts (I feel for them) - it would be fair and reasonable of you to supply clear answers to these questions.

EDIT: Grammar edit for clarity
« Last Edit: February 07, 2018, 04:05:36 AM by agent_smith »

roo

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Re: Cordage Movement & Melting Damage Risk?!
« Reply #28 on: February 07, 2018, 04:23:46 AM »
That wasn't an answer to my question.

So I'll ask the question again: "Who's test results are you referring to?"

And to take it a step further:
1. Have these test results been peer reviewed?
2. Have these test results been submitted to rock climbing harness manufacturers for their comment?
3. And to be 100% crystal clear - are you advising to the world at large - that a tie-in knot to a rock climbers harness can be a noose?
You know very well that I've been conducting the tests.  And I also know that you've been seemingly unwilling to do the same, with a deafening lack of evidence of the assertions you've been making (nylon melting, etc).
 
I also find it odd that you want me to submit my tests to manufacturers when:
I would disregard any advice to the contrary - and I stand by my advice outlined in this post. This includes any published advice even from some manufacturers - who in some cases do not have vast experience or expert level knowledge themselves. Some manufacturers have little actual field experience and some are over-populated with sales staff who are good at selling but not much else (ie spin doctors).
Mark

I notice in your Analysis of Bowlines paper, you don't even have any test results to submit to manufacturers about the knots you recommend for life support.

I wish you'd spend half of the energy you put into being so defensive with your list of "must haves" in testing into doing some actual testing of your own.   
« Last Edit: February 07, 2018, 04:36:33 AM by roo »
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agent_smith

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Re: Cordage Movement & Melting Damage Risk?!
« Reply #29 on: February 07, 2018, 04:41:54 AM »
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deafening lack of evidence
Yes - it is deafening lack of evidence to prove your claim.
It isn't falling on my deaf ears though. I am still listening intently for you to answer the questions.

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I also find it odd that you want me to submit my tests to manufacturers
I find it odd that you try to obfuscate the issue.
Digging up old posts proves what exactly?
You are trying to apply a meaning to old words out-of-context.
Again, you are obfuscating the issue - about your claim that a noose can be used as a tie-in knot to a rock climbers harness.

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you don't even have any test results to submit to manufacturers about the knots you recommend for life support
Obfuscation.
The issue is using a noose as a tie-in knot to a rock climbers harness.
The secure Bowlines in my paper are fixed eye knots - they do not act like a noose.
Secure Bowlines such as Scott's locked Bowline function well with EN892 and EN1891 life support ropes.
I routinely tie-in with the #1010 derived EBSB (secure) Bowline for lead climbing - which is a fixed eye knot (it is not a noose).
I have personally led over 100 routes using this knot as a tie-in (and fallen on it).
I have also started to use Scotts locked bowline for building anchors and also as a tie-in to a rock climbing harness. I haven't used Scotts locked Bowline as much as the 'EBSB' Bowline...but so far it is functioning perfectly well. I have not a had a free-fall onto Scotts locked Bowline yet...

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I wish you'd spend half of the energy you put into being so defensive

The person who is actually being defensive is you.
Reasoning: You have made a declaration to the world at large (using the IGKT forum as a vehicle) - stating that it is safe to use a tie-in knot that acts like a noose to a rock climbers harness. This is effectively giving advice.
I challenged your assertion.
You are being defensive because you don't like being challenged - it irritates you.

I believe that the onus of proof falls upon you to prove your claim that it is safe to tie-in to a rock climbing harness with a knot that acts like a noose.

Because many climbers lives might be at risk because of your advice to use a noose, this places your claim in a high risk category - and so there is a higher burden of proof that must be applied. This is particularly so because it is also counter to what rock climbing harness manufacturers advise.