Author Topic: Figure 8 Loop  (Read 14742 times)

xarax

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Re: Figure 8 Loop
« Reply #30 on: May 15, 2015, 11:29:44 PM »
Slightly off topic, but this is an interesting related experiment:
http://demo.physics.uiuc.edu/LectDemo/scripts/demo_descript.idc?DemoID=1193
However, they left off the really fun part.  Once the rubber band is stretched and the heat dissipates, let it shrink back again and it really feels cold against your skin.

   Nice experiment ! Very interesting ! Thanks for the reference.
This is not a knot.

knot rigger

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Re: Figure 8 Loop
« Reply #31 on: May 16, 2015, 05:48:28 AM »
Quote
From DownUnder :
Right and wrong Figure-of-8 knot
http://www.ropelab.com.au/right-and-wrong-figure-of-8-knot/

A shame I have to pay to read this,  Xarax, anychance you have the text of this article without me having to become a member of this site?

Quote
Watch the video. https://www.youtube.com/watch?v=s3fHYGY3YTo

SS, fantastic video,  thanks for posting it.  It's very interesting.  I especially take note of which "weak" or "strong" form they happened to have tied!

Quote
Quote
A person can tie #1047 deliberately 'messy' - and it will still hold a falling climber.
NB : "messy" is a non-particular description!  One messy
orientation and another one might be quite different in effect?!

Dan, I knew exactly what A_S meant by "messy" dressing of the knot.  And I completely agree with his point: that while a messy dressed fi 8 may be weaker, and may be more prone to jamming after a fall... It's still adequate to the task at hand, and there is no reason to fear a "messy" knot would not hold a climber's fall.  All things considered, I personally dress all my fig 8 loops as well as I know how before they are loaded, but if I inspected one that was "messy" I may not fix it right away, depending on the circumstances.

Quote
Knot_Rigger, per you questions, the HSE report (one of a few?) is:
www.hse.gov.uk/research/crr_pdf/2001/crr01364.pdf‎

I got a 404 error when I tried that link

Quote
Quote from: knot rigger on May 15, 2015, 05:48:38 AM
Agent_Smith:
I wholeheartedly agree with everything you say in your post.
You are are ready to parrot him, then!

What he says makes sense, and to agree with what makes sense isn't "parroting" IMO.  (btw It's off topic but I don't care for the EDK myself, but I come from things more from a rope's access viewpoint than a sport climbing point of view)

Quote
Quote
I often need to calculate the safe working load of a system,
and the difference would matter to me in this situation,
We should all find this sort of statement entirely DUBIOUS :
what sort of basis do you have to play around with such
*numbers* as though they mean something?!

Dubious?  really?  I was just pointing out how in my line of work, am indeed concerned with efficiencies of knots.  What about that do you think is "entirely dubious"  or what about this statement of fact (it is a fact that I do load calculations involving efficiencies of knots) should "we all" find dubious.

The point I was driving at was accuracy.  If you hadn't have truncated my quote, the point would (perhaps) been more clear.

here is the full quote:

Quote
I often need to calculate the safe working load of a system, and the difference would matter to me in this situation, but only so far as getting the calculation as close to accurate as possible.  All (well done) rigging load calculations carry a comfortable margin of error in the design factor.

you go on to ask:

Quote
Tell us, how do you do this clever calculation of yours?...

I will be brief, as this is off topic of the thread:  Suppose in the course of inspecting some show rigging, we find a problem with a 400 lbs speaker system.  (perhaps there is a side loaded shackle that we need to fix)  Due to the details of the situation, we determine the best way to proceed is to temporarily lift the speaker with rope.  What we have on hand is 11mm Kernmantle with a breaking strength of 6000 lbs.  Given the nature of the load, the industry 'best practice' for lifting with fibrous rope would be to use a 10 to 1 design factor.  A 10:1 DF with a 75% efficient termination would give us a safe working load of 450 lbs.  A 10:1 DF with a 65% efficient termination would give us a SWL of only 390 lbs.  Less than the given load we need to lift.

This example may seem contrived to you, but I assure you that I have made these sorts of "on the fly" safe working load determinations many times.  You may think that a mere 60 lb difference between knot efficiencies isn't that much and doesn't matter that much in real life, and in a way it doesn't.  The healthy safety margin is a buffer against human error, the necessity of estimation, errors of information, and unforeseen loading events.  And that same safety margin would let me sleep at night, even if the rigger who tied the figure 8 knot we used happend to tie the weaker form.  However, I would like to do my calculations as accurately as I can, and there lies my interest in the question at hand.

One last point about my example.  The actual difference of 10% efficiencies in the knots would yield a 600lb difference in ultimate breaking strength.  The 600 lbs difference is larger than the 400 lbs load we're lifting!

xarax

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Re: Figure 8 Loop
« Reply #32 on: May 16, 2015, 01:02:29 PM »
the text of this article without me having to become a member of this site ?

  I do not have it either !  :)  It was just an effort to make out friend from DownUnder, agent smith, reply - I guess he knows the writer in person, and he can tell us more about the whole thing.
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Mobius

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Re: Figure 8 Loop
« Reply #33 on: May 16, 2015, 03:05:25 PM »
the text of this article without me having to become a member of this site ?

  I do not have it either !  :)  It was just an effort to make out friend from DownUnder, agent smith, reply - I guess he knows the writer in person, and he can tell us more about the whole thing.

I live 'DownUnder' too, in Sydney :)

I have to say that the site looks really interesting and from reading their blurb it seems they do testing.

roo

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Re: Figure 8 Loop
« Reply #34 on: May 16, 2015, 04:31:47 PM »
Of course the rest of the surrounding knot parts (geometry) will carry away/absorb the heat, though I don't really see what that statement proves here.
I was thinking more along the lines of heat being lost to the surrounding airflow via convection and to space via radiant heat transfer.  In other words, the more exposed regions would lose heat faster, skewing the relative stress results to some degree.
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Dan_Lehman

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Re: Figure 8 Loop
« Reply #35 on: May 16, 2015, 06:03:21 PM »
Quote
Knot_Rigger, per you questions, the HSE report (one of a few?) is:
www.hse.gov.uk/research/crr_pdf/2001/crr01364.pdf‎

I got a 404 error when I tried that link

And so did I, clicking on your copy of my URL!?!  ???
Well, I retrace my fetching steps (Google produced)
and again am using URL  into the PDF.

Here is the combination of "404" <> "working" URLs,
between which I've not been able to see any difference:
http://www.hse.gov.uk/research/crr_pdf/2001/crr01364.pdf‎<>
http://www.hse.gov.uk/research/crr_pdf/2001/crr01364.pdf
I copied above from my window's URLocator window,
in which I first got 404 from the left half (w/o extension of R),
then pasted in the R half which had just seen me INTO the PDF!?
HUH???  The '0' are indeed zeroes & all identical.
NOW --while typing this Reply--,
I copy-past tope URL from 'www' on, and ... "404".
I do the same with 2nd line, similarly, and ... AM IN!?!?!?
Holy double-vision, Batman,
what's going on here?
UPDATE :: By tediously using window Find and parts of
these URLs, I reach a non-matching point at 'p' of 'pdf' !?
I.e., URLs match up through final period but fail at an
apparently identical 'p'!?!?
MORE bizarre :: I just cut'n'pasted the offending 'pdf'
into Find window; all the OTHER "pdf"s --i.e., lower AND
uppercase-- were highlighted in yellow of multiple occurrences;
but, Next used in Find DID TOUCH THE UN-HIGHLIGHTED 'pdf'
of the offending/404 URL.  !?!?

(Google "hse Lyon Equipment knots test" and you should get
your own, if one of the (two identical (l00king!)) URLs above,
here, fails again.

... baffled ...  :o   :-[   :-\    ::)   :o
[edit : I just clicked on embedded --by system-- URLs above,
and again the 1st/upper one got "404", the 2nd apparently
identical one got me to the PDF.]
>>> now, putting both 'pdf', '.pdf', and fuller ending
of these URLs, I see ALL of them highlighted (by Find)
on this forum page, and Next to all, also (whereas before,
doing Next/Find in my post-compose window, I got the
odd yellow-highlighting EXCLUDING the offending URL's 'pdf',
but Next went to it, anyway.   :o   



Quote
Quote
Quote
I often need to calculate the safe working load of a system,
and the difference would matter to me in this situation,
We should all find this sort of statement entirely DUBIOUS :
what sort of basis do you have to play around with such
*numbers* as though they mean something?!

Dubious?  really?  I was just pointing out how in my line of work, am indeed concerned with efficiencies of knots.  What about that do you think is "entirely dubious"  or what about this statement of fact (it is a fact that I do load calculations involving efficiencies of knots) should "we all" find dubious.

...  A 10:1 DF with a 75% efficient termination would give us a safe working load of 450 lbs.
A 10:1 DF with a 65% efficient termination would give us a SWL of only 390 lbs.  Less than the given load we need to lift.
Really, my point isn't obvious to you --and I gave it
in fuller terms than you quote?!?  You pick 65 & 75%,
and I questioned explicitly (a) how someonElse's figures
can be seen as relevant to your materials (and nature
of loading/forces), and (b) how you would you deal with
the 30%-points (51 vs. 81) difference in the CMC two
reference works!?
Ergo, ... "dubious"! (& QED  ;) )

You seem to imply --don't explicitly say-- that your different
(75/65%) figures attach to distinctly different terminations;
my point mainly was, in addition to taking that value at its
face, how you deal with the multiple values given for the
--nominally/apparently-- SAME termination!
(And, now with this URL mystery, how do we do ANYthing!)

--dl*
====
« Last Edit: May 16, 2015, 06:11:23 PM by Dan_Lehman »

SS369

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Re: Figure 8 Loop
« Reply #36 on: May 16, 2015, 11:09:11 PM »
Of course the rest of the surrounding knot parts (geometry) will carry away/absorb the heat, though I don't really see what that statement proves here.
I was thinking more along the lines of heat being lost to the surrounding airflow via convection and to space via radiant heat transfer.  In other words, the more exposed regions would lose heat faster, skewing the relative stress results to some degree.

I would think that instead of skewing the results, that would be part of the results. Even if you froze or chilled the rope, the thermal action would still be part of the equation.
The main point of providing the link was to be able to see the tightening action of the Fig. 8 (most people will never stress theirs that hard nor have a camera on it when it does, or see it when they take a whipper) and where the stress induced the disastrous result.

SS

agent_smith

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Re: Figure 8 Loop
« Reply #37 on: May 17, 2015, 03:21:14 AM »
After searching for Lehman Figure 8 and Nobel prize in the same sentence (never found the Nobel prize) I stumbled across this site:
http://www.elementrescue.com/Element_Rescue/Main_Blog/Entries/2014/8/2_The_Bowline..._Dont_call_it_a_comeback.html

Couldn't determine the author of the site - but I did find a Audie Murphy likeness (I wonder if he looks like Dan Lehman)?

Just to be clear - I wouldn't be posting in this forum if I didn't have an interest in all things knotting (although my primary interest is in the area of knots used in life support applications).

With regard to Richard Delaney and the 'Rope test lab' site - I am on facebook so I can post there - and I know Richard personally (I actually trained him as an instructor back in the 1990's). Richard is an enlightened man - very knowledgeable and passionate about climbing, rescue and anything that is captured under the general banner of technical roping. He has worked hard to put that facebook page together and make it work - and more power to him if he can generate some income from it (why not).

I will say that I don't agree with the term 'right' versus 'wrong' way to tie ABoK #1047 (Figure 8 connective eye knot). I would be more supportive of the term 'higher efficiency' versus 'lower relative efficiency'. Using terms such as 'right' and 'wrong' might lead to mass hysteria and needless concern that death is imminent if the lower efficiency form of #1047 is tied and relied upon.

If a trainee under my direct duty of care stood before me and tied the lower efficiency version of #1047, I would not cry foul and declare death to be imminent. And if the trainee paid zero attention to dressing (symmetry and form) and created a random 'messy' structure, I still wouldn't be concerned about imminent death - although I would argue a case for consistency and predictability/behaviour under  load. I support consistency when rescue teams tie knots - and I support the notion of attention to dressing because it makes the knot more predictable under load (it doesn't tend to alter into a distorted form under high loading - AND, it makes it easier to check and detect errors).

To declare the lower efficiency #1047 as 'wrong' would (in my view) have to be justified against a whole host of other connective eye knot - eg the Bowline family of knots. This comes down to the issue of pure strength - whilst ignoring more important factors such as security and stability (and ease of untying after high loading event). The Bowline (secured form) is just as good - and better in my view - than a 'high efficiency' #1047.

Dan Lehman referred to Highlines - I always prefer to use a capstan-like hitch such as the so-called 'tensionless hitch' in highline rigging (ie for end terminations to anchors). If you really are going to put some outrageous loading on a highline system - what better 'knot/hitch' than the 'tensionless hitch'? Obviously its not a connective eye knot like the Bowline - but it is fit-for-purpose in such an application. If for some reason I couldn't employ a tensionless hitch - I would use a secured Bowline (not #1047) - because #1047 would more likely than not jam.

I know well enough about threading little bits of cotton thread tracers in ropes in preparation for break testing. I remember cursing Dan Lehman under my breathe years ago when he urged me to do this. I dont think my eyes could handle the strain anymore... But I agree that it is the proper method in knot testing.

And this type of research and discussion is a worthwhile exercise and it interests me - but it doesn't alarm me.

Pure research can lead to world changing breakthroughs - like studies of quantum physics led to the invention of the transistor which then opened the way for computers which then opened the way for the internet and me typing this post today :)

I dont know if the Lehman 8 is worthy of a Nobel prize though   ;D

Mark Gommers

« Last Edit: May 17, 2015, 03:26:48 AM by agent_smith »

roo

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Re: Figure 8 Loop
« Reply #38 on: May 17, 2015, 07:21:30 AM »
I was thinking more along the lines of heat being lost to the surrounding airflow via convection and to space via radiant heat transfer.  In other words, the more exposed regions would lose heat faster, skewing the relative stress results to some degree.

I would think that instead of skewing the results, that would be part of the results. Even if you froze or chilled the rope, the thermal action would still be part of the equation.
The main point of providing the link was to be able to see the tightening action of the Fig. 8 (most people will never stress theirs that hard nor have a camera on it when it does, or see it when they take a whipper) and where the stress induced the disastrous result.

SS
Hmm.  You may be thinking that those color maps are indicating more heat than what's actually being produced.   Those temperature variations are fairly mild (maybe around 10 degrees Celsius variation looking at the final chart of the video). 

To put a different angle on my previous comment, if you paused the test and let all those mild temperature variations dissipate, you'd get a very skewed result of it looking like all portions of the knot have equal stress, for example.
« Last Edit: May 17, 2015, 07:35:20 AM by roo »
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xarax

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Re: Figure 8 Loop
« Reply #39 on: May 17, 2015, 08:52:31 AM »
I support the notion of attention to dressing because it makes the knot more predictable under load

   I believe you should support the notion of attention to dressing, just because it requires ATTENTION, and attention is of paramount importance in your field... One should pay attention to anything he does - so he should also pay attention of how he ties the fig.8 bend or loop, or ANY bend or loop for that matter.

   However, there are more than TWO the possible symmetric forms one can dress the fig. loop, and until you do not pay attention to THAT simple fact, you are just parroting what it is parroted all those years by all those people - and I believe that this is NOT your style !

Pure research can lead to world changing breakthroughs

  It was always like that... so, somebody should tie and try, systematically, ALL the different symmetric forms of the fig.8 loop - which are MUCH more than TWO !  :) :)  NOT because some are weaker and some stronger, right or wrong, more or less efficient, etc, but simply, as you climbing people like to say, because they are there:) :) :)
« Last Edit: May 17, 2015, 08:54:53 AM by xarax »
This is not a knot.

agent_smith

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Re: Figure 8 Loop
« Reply #40 on: May 17, 2015, 01:16:23 PM »
Thank you for assuming that I am parroting a parrot Xarax. I would have preferred to parrot you instead of all the other parrots. A wise man once told me to never 'assume' - because it could make an Ass out of U and Me. So don't assume this parrot has parroted all the other parrots without first checking whether the parrot really was parroting the parrots.

Just parroting a bit more, this thread is receiving a lot of attention compared to other topics - I wonder why?

My point re 'dressing' was in fact used in a generic sense - in that it is desirable to achieve symmetry of form for the reasons I stated previously. I was not deliberately pointing toward any absolute dressing forms (weak Vs strong or whatever description you prefer) other to say that random tying without paying any attention to any particular dressing is not best practice and can cause issues.

Xarax, may I suggest that you join the rope test lab Facebook page and then pay the small subscription fee so you can provide commentary on their test results. Then you could report back here...


knot rigger

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Re: Figure 8 Loop
« Reply #41 on: May 17, 2015, 10:17:21 PM »
Quote
With regard to Richard Delaney and the 'Rope test lab' site - I am on facebook so I can post there - and I know Richard personally (I actually trained him as an instructor back in the 1990's). Richard is an enlightened man - very knowledgeable and passionate about climbing, rescue and anything that is captured under the general banner of technical roping. He has worked hard to put that facebook page together and make it work - and more power to him if he can generate some income from it (why not).

I have joined Mr. Delany's RopeLab website.  A_S, you convinced me, although I don't think that was your explicit intent.  I figure it's worth $60 to support the work of someone whose passions I share.  Also A_S, let me congratulate and thank you for your paper about the Bowline [ http://tinyurl.com/mkkcwbp ] which I have found very interesting and usefull.  Thanks as well for the link to element rescue site.  I've emailed Mr. Delany asking permission to share the whole of his article about the figure 8 knot with this thread.  In the mean time, I will attempt to summarize.

First, I like one way that he refers to the difference between the forms: by the path of the standing end; so we have an "inside" version, and an "outside" version.  I find these two terms superior because they don't have any implied judgment attached, they just describe the topology of the knot.
Second, his article is mainly about how easy it is to untie the knot after heavy loading, not pulling to rupture.  But this is very interesting in what he finds, and one conclusion he proposes.  He found that the "inside" version (aka "weaker") was harder to untie after heavy loading.  He also saw that often (but not always) the "outside" form "flipped" (his term) such that the outside bend flipped to the inside position with applied tension.  He loads the knot on common 11mm static ropes used in the ropes access industry, and chose to test them up to, and exceeding the Safe Working Load of the rope. 
Lastly: He draws this conclusion (in the form of a hypothesis)

"Further tests may be also confirm that that figure-of-8 knots that are difficult to untie may have been loaded above 5kN and thus above the SWL of the rope.  If this is the case then the figure-of-8 knot is certainly a good choice for anchoring ropes in tech rescue and rope access work."

I find this an interesting thought, that the knot is both the anchorage, and the indicator of potential abuse.

Ok then, Dan Lehman, thanks for clearing up the link to the HSE report.  I'm no wizzard with computers, and have no idea what went wrong there, but thanks for re-posting.  It turns out I have seen this report, but I had forgotted or neglected the information about the inside/outside versions of the fig 8 knot.  To summarize for the thread (you had already, but I will too)  for the overhand loop, the outside version is stronger, for the fig 8 loop inside and outside are the same strength, and for the fig 9 loop, the inside version is stronger (all according to the HSE report).  It's off topic, but anyone who climbs or does rope access work should read section 7 of the report about "cowstails", and be VERY cautious about using sewn cowstails.

more from DL:
Quote
Really, my point isn't obvious to you --and I gave it
in fuller terms than you quote?!?  You pick 65 & 75%,
and I questioned explicitly (a) how someonElse's figures
can be seen as relevant to your materials (and nature
of loading/forces), and (b) how you would you deal with
the 30%-points (51 vs. 81) difference in the CMC two
reference works!?
Ergo, ... "dubious"! (& QED  ;) )

You seem to imply --don't explicitly say-- that your different
(75/65%) figures attach to distinctly different terminations;
my point mainly was, in addition to taking that value at its
face, how you deal with the multiple values given for the
--nominally/apparently-- SAME termination!

How do someone's else figures apply to my materials and conditions?  They don't, but the information is applicable in that the materials and conditions are approximatly the same.  In other words, I have to make a judgement call.  I base my decisions on the best knowledge of knot efficiencies I can find, then employ a large design factor to (among other things) protect against inaccuracies in reported knot efficiency.

As far as the figure 8 bend goes, I would used the most conservative efficiency of the two from CMC (and/or the most conservative I can find from multiple sources)  Specifically to the fig 8 bend, I choose not to use this knot!  There are stronger bends for high load applications (double and triple fisherman) and more convenient to tie bends for low load applications (double sheet bend).  [the zeppelin bend may be better for both applications, and I use it, but I haven't yet seen good efficiency data on the knot, and avoid it for life critical applications]

To make a judgment call about any given knot efficiency, and how it affects what knot I use, I would employ these criteria: 
(1) compare as many published accounts as possible of knot efficiency
(2) consider failure states (does it slip, jam, break, etc)
(3) consider the application to determine what is the most important; security, strength, ease of tying, ease of untying
(4) consider that my work will be inspected by others, and for that reason I may choose a more widely know knot over a "superior" one


xarax

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Re: Figure 8 Loop
« Reply #42 on: May 18, 2015, 07:17:18 PM »
   Climbers are sooo poor knot tyers ! They know only a very small number of knots ( and they even naively believe that these knots are the only ones, and the best possible ones, suitable for them, simply because they do not know anything else...), they do not know ( and they do not want to learn ) how those knots "work", they do not know ( and they do not want to try to figure out ) how to improve them, and, last but not least, they just do not care about knots ! Fortunately, knots were tied, tried, studied, and improved by sailors. If the water on planet Earth was less or was frozen, perhaps we would have had more climbers and fewer sailors - but I am sure we would have had fewer and worse knots !  :)
   When a knot tyer watches this video with the fig.8 loop, the very first thing he notices, is the most obvious thing : the initial shape of the fig.8 loop is distorted very unevenly, to a degree it becomes unrecognizable. Then, the next thing he notices is that this outer "higher" collar seems to be almost unloaded, that it, almost redundant ! Evidently, it does not participate in the dissipation of the tensile forces as mush as the other segments of the nub - and when a structure does not utilizes some of its available elements, or a knot does not utilizes some of its segments, it is not an optimally designed mechanism : it uses more material than it needs, and it uses it in a non-optimal way.
   Therefore, it is reasonable for a knot tyer to think that this knot could perhaps be "abbreviated" ( Dan Lehman s term ) : it can become less convoluted, yet remain as secure as the fig.8 loop - and perhaps it may become even more secure ! We can not be sure about the role played by the much less loaded/utilized elements, as this outer "higher" collar - it may be positive, but it may also be detrimental, and contribute in a less favourable loading of the other elements, which carry the largest percentage of the burden induced by the tensile and compression forces inside the nub.
   And, just after that, a knot tyer will ask himself if an "abbreviation" of the fig.8 loop would improve it regarding its greater problem, the difficulty of untying it after heavy loading. Perhaps a smaller, less convoluted knot, which consumes less material, but which utilizes this material in a more even and efficient way throughout its nub, would be easier to untie.
   My understanding, judging from the conservative, to say the least, way climbers see knots, is that an "abbreviated" fig.8 loop would never persuade them that it is equally or even more effective. However, perhaps the opposite strategy may work : Leave the redundant elements there, in their almost decorative role, and add something more, which will improve the overall balance and achieve a more even distribution of the forces  inside the nub, so the knot will be distorted less, and will become more easy to untie. This was the meaning of my idea to "plant" / "nail" / retuck the Tail End through a properly chosen opening of the fig.8 loop, so the equilibrium of tension, compression and torsion inside the nub becomes more pronounced.
   To whom am I telling this ? To people that have never just think for just a minute about the number of different dressings a fig.8 loop may have ?  And they still believe in the TWO infamous "strong" and "weak" forms, TWO "more efficient" and "less efficient" dressings, etc... ? In short, in the ying and the yang ?  :) And they call me, the poor old sailor who dares to tell them that there are more stable and symmetric dressings of the fig.8 loop, a parrot:)  :)

   It was always like this, even in the purest scientific fields, like physics. The new ideas were established, only after the previous generation of physicist had retired... Perhaps, in the future, some young climber, who will also happen to be a knot tyer, will tell himself : " Enough, with this sacred fig.8 loop ! Let us search for something else.."

   The parrrrotttt.   
« Last Edit: May 18, 2015, 07:24:57 PM by xarax »
This is not a knot.

xarax

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Re: Figure 8 Loop
« Reply #43 on: May 18, 2015, 10:45:28 PM »
   If any member thinks that the previous post is not fair to climbers attitude about knots, I would had wished and asked him to tell this me so, and PROVE it by refuting, word by word, sentence by sentence, what I have written there. However, judging from past  experience, I do not expect something like this to happen... Climbers, in particular, or people who believe they know better about the fig.8 loop, just because they "use" it more often than me, will just ignore it, and will never reply - as they did in all my previous posts and attempts, years now, to show the many different table and symmetric forms the fig.8 loop can have. The same had happened with my post about the alleged superiority, re. strength, of the fake, so called "Zeppelin loop" relatively to the secure  bowlines - no answer, ever... ( And I am not talking about a-symmetric dressings, which are numerous, and which, given the a-symmetric way a loop is loaded, perhaps they will be even more optimally dressed ).
This is not a knot.

SS369

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Re: Figure 8 Loop
« Reply #44 on: May 19, 2015, 12:04:15 AM »
   If any member thinks that the previous post is not fair to climbers attitude about knots, I would had wished and asked him to tell this me so, and PROVE it by refuting, word by word, sentence by sentence, what I have written there. However, judging from past  experience, I do not expect something like this to happen... Climbers, in particular, or people who believe they know better about the fig.8 loop, just because they "use" it more often than me, will just ignore it, and will never reply - as they did in all my previous posts and attempts, years now, to show the many different table and symmetric forms the fig.8 loop can have. The same had happened with my post about the alleged superiority, re. strength, of the fake, so called "Zeppelin loop" relatively to the secure  bowlines - no answer, ever... ( And I am not talking about a-symmetric dressings, which are numerous, and which, given the a-symmetric way a loop is loaded, perhaps they will be even more optimally dressed ).

Climbers or sailors for that matter, do not have to refute anything, line by line or any way.. Some may care to as had happened with the men from Sailing anarchy with their testing, but refuting is not what all this is about. It is, imo, about sharing and learning and what we figure out.

I am a climber, I have sailed (not the ships of yesteryear) and use knots almost daily, besides tying my shoes. (They don't come undone during the day  ;) ). I also like to explore new things and I tie every offering here and elsewhere. I show the one's that have merit to me to others who climb and work, they decide whether it is for them or knot. When your life is dangling on a knotted rope, the climber/rescue tech or the sailor of yesteryear or today keeping his rigging working is the one who makes the decision.

I am sure that many who have read and will read the articles posted here will find some things interesting, even go so far as  to make their own test rigs and test them out. They don't have to do this or refute anything. And if they are hounded or condescended to, guess what, they leave. Or decide to lurk and not contribute anymore. I have seen this a few times.

No, I wouldn't support the statement that climbers are soooo poor knot tyers, they may not have the same zeal as others. Some tie very nice looking Fig. 8 loops or anchor knots or bowlines and bends. Best of breeds, who knows?
Some just want to climb. Not such a hard concept.

There are climbers and sailors who tie much , much more convoluted knots than what is offered here and they don't claim that another tyer is is a poor knotter because he is at a different level of understanding or interest.
We cannot force another to show interest they do not have.

I strongly suggest that we, the members of this forum, stick to knots with friendly, interesting discourse. Period.

SS