Figure 8 Loop

Practical Knots
41

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…

42
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:

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

43

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 ! :slight_smile:
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 ? :slight_smile: 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 ? :slight_smile: :slight_smile:

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.

44

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 ).

45

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 :wink: ). 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

46
Climbers are sooo poor knot tyers ! They know only a very small number of knots

Now your parroting might have stepped over line.

Many climbers are very good at tying the knots they use on a routine basis. Jim Bridwell (‘the Bird’) was quoted as stating that he climbed all of his famous routes using less than 6 knots.

Many climbers would argue that knowing a small handful of knots very well is better than knowing hundreds of knots less well. In contrast, an IGKT member will want to intimately know hundreds of knots and hitches and the science behind them.

My main point here is that climbers are not knotting enthusiasts like the members of the IGKT forum. Climbers see knots as tools (like a screw driver). They dont really care how the screw-driver is designed - they just want to know that it works.

You see, IGKT members are passionate about knots and knotting - thats why they are involved in this forum. You wont see many rock climbers in the IGKT forum - because they are more interested in being outside enjoying their sport - and challenging themselves in the vertical world.

You cant criticise them for (knowing and using only a select few knots) because they are simply wanting to participate in and enjoy their sport. They want to improve their climbing ability and push their personal limits. The harness they wear, the rope they use and the knots they tie are just means to an end. Most climbers are using either the Figure 8 eye knot or some secured Bowline derivative - all they care about is that it will not fail - it will save their life if they fall.

Xarax, in making such comments (“climbers are sooo poor knot tyers”) you are judging others against your personal knotting values and morals. You have a different objective (and different type of passion) in mind than the average climber.

Not everyone will share your passion for knots and all things knotting - you cant force your set of values (about knots) on others.

…

Edited for enhanced clarity…

47

Of course they “do not have to”, if they are not interested in what I had said - but if they claim I had not been fair to them, they HAVE to explain why ! When one says that somebody is too damning in what he says, he has to prove it - otherwise he just ignores it.

When you participate in an “open” Forum, where everybody tells his own thing, and for his own reasons, which do not always have a relation with the issues discussed, you run this danger, indeed. Personally, I were “hounded or condescended to” DOZENS of times, but my love for the knots themselves had kept me in - at least until I will be kicked out … :slight_smile:

First, I was speaking generally, about the average climber, not the rare climber who happens to be a knot tyer, or vice versa. Second, I had elaborated a little on this statement : I said :

  1. They know only a small number of knots. ( True or false ? )

  2. They do not know ( and they do not want to learn ) how knots “work”. ( True or false ? )
    I have followed many discussions on climbing sites, I have a few friends who are climbers, and I have never ever met one who tries to “see” a knot not only as a “tool” which has only to “do the job”, but also as a structure, as a mechanism, in order to get some idea of how and why it “works” the way it “works”. Some of them had tested some knots, that is true, but only very few knots, on a very limited number of samples, on a very limited variety of materials - and they had never tried to modify the knots they already know, and test those modifications, too, to explore some hidden potential. The only kind of knots where there have been some experimentation, is the climbing gripping hitches, but even thee there is no explanation of why some work better than the others… I had read only some hand-weaving arguments - not convincing at all, I should say.
    In particular, in their beloved, basic knot, the fig.8 loop, they still have not seen that there are many stable ways to dress it, not only two, as parroted again and again, and that some of them may be significantly better than the others, if not re. strength, at least re. easiness of untying. Also, I had never ever see any modification of the holy fig.8 loop. I said that :
    4. They do not know ( and they do not want to try to figure out) how to improve them. ( True or false ? )
    Why ? Will it punish us as heretics ? Is its form carved in stone, and can not be changed, ever ? WHO had proved that this is the One, and the Only, and “Best” super-duper loop in the Universe ? HOW had he did that ? Is the “argument” that, “because it does not kill the climber, it is OK” any sort of “proof” or “explanation” which one can discuss seriously ? So, any knot which does not kill the user, is OK, and we have to use this, and nothing else, the nest 4 billion years ?

    THOSE were the 4 lines / which one should first discuss, before he starts to claim that I was not fair with climbers… Of course, he can ignore my arguments, but then I can also ignore his whining about my unfair and/or too damning critique of the knotting abilities /interests of climbers.

…While when one just wants to know how things work, and how knots work, and how many different knots can exist that do the same thing with the minimum danger of slippage, with minimum amount of material, with minimum time required to tie and/or untie them, THEN it becames a HARD concept… :slight_smile: :slight_smile: :slight_smile:

Do me a favour, SS369. Suppose, just suppose that I believe I have some reasonable arguments, and that my opinion is not totally unfounded or biased, and I think that the answer in all those 4 questions above is “True”. WHAT word should I use ? If “poor” is not the proper word ( it was the first word that came into my mind…), which is the word that describes thi s hypothetical, at least, situation fairly and squarely ? Please, tell me, and I will edit my previous text immediately.
I do wish to provoke discussions, not bad feelings ! I do not consider myself a genuine/proper :slight_smile: knot tyer, because I do not test knots, so my argumenta are mostly of the hand-weaving, or line filling, kind… However, I just want to learn from other more experienced and knowledgeable people. Not such a hard concept. :slight_smile: :slight_smile:

48

Tell it to people who do not like the picture of my avatar ! :slight_smile:

Is this an argument against my statement, that they know only a few knots ? :slight_smile:
I can do ALL of my famous walking, using shoelaces tied with only ONE knot ! :slight_smile: Am I a good knot tyer ? :slight_smile:
It is amusing how people defend what they are doing - If somebody needs or uses 6 knots, and he is “very good at tying them”, he is a GREAT knot tyer ! :slight_smile: I use only ONE knot, and I tie it magnifically, so I suppose this makes me a Knot-semi-God or something… :slight_smile:

It is boring to me to quote, line by line, word by word, sentence by sentence, how many times I had said the same things, and I have repeated them in the text to which you supposedly reply. So, please, you do not have to parrot me, while, at the same time, you are trying to argue with what I say ! Because, if you do this, THEN, “[i]your parroting might have stepped over line..” /i

WHO did that, WHEN ? Are you imagining you are talking to Savonarola ? :slight_smile: :slight_smile:
http://en.wikipedia.org/wiki/Girolamo_Savonarola

I am judging others in comparison to something they do NOT do, either because they do not love it, as I do, or they are not interested in it, or because they simply do not need to do it ! They do NOT tie enough knots, they do not know how they work, they do not want to improve them. HOW on Earth ( UpOver or DownUnder this Earth ) have you IMAGINED that !@#$%^&*()_+ “against my personal values and morals” (sic) ? Are knots “values” which are endowed with "morals ? :slight_smile: :slight_smile: I do not play tennis, if somebody tells me that I am a poor tennist , he is " judging me against his personal knotting values and morals " ? :slight_smile: :slight_smile: :slight_smile: Is tennis a “value” or a “moral” ? :slight_smile: :slight_smile: I do not speak English, but I start to believe that we should start to talk to each other in LATIN, or something, because what you say is all Greek to me !

I quote your fair statement about me again, so you will enjoy it a little longer !

@ SS369 : Now you know how "we, the members of this forum, stick to knots with friendly, interesting discourse."
Period.

49 
As I might had expected, I am already under the crossfire of two climbers, who, perhaps in their subconscious effort to prove that I am not mistaken in what I had said  :), they had not written A WORD, not even ONE single word, about the crux of the matter, explained in the 5 ( = five) paragraphs after the first, of my reply at :
http://igkt.net/sm/index.php?topic=5313.msg35501#msg35501
I have to suppose they had read only this first paragraph, or only the first sentence of this paragraph - because all those 5  next paragraphs were about the [i]fig.8 loop[/i], and only about the [i]fig .8 loop[/i], about which I am parroting, of course, and I do not know, but which they "use", so they know.
50

Perhaps if you had not expected what you perceived, it would not happen.

You are not in any crossfire. Something you wrote was disagreed with (Your opening remark) and the all consuming statements are not fair to the members who may not have your zeal. One cannot make another thirst for learning, especially by calling them out.
Ridicule is the worst education tool that I know.

Do me a favour, SS369. Suppose, just suppose that I believe I have some reasonable arguments, and that my opinion is not totally unfounded or biased, and I think that the answer in all those 4 questions above is "True".

So what. They come here for some reason and should not be made to feel little. They may be budding tyers and want to learn from such masters.

As for your other Fig 8 layups, prove that they are better. Test them.

This is off topic nonsense and I care no more for it. So, if you’ll take it private with whomever you want to, go for it.

SS

51

I wrote my opinion about the majority of climbers, NOT about the members of this Forum ! If I will be censored for my opinion, fine ! I have been censored before, and I know… I said that climbers, IN GENERAL, are poor knot tyers, and I mean it, and nobody told me which more correct/proper word I should had used ! I know enough climbers, and I read enough posts in enough climbing Forums to have an opinion on this matter, I believe. Other members will have other opinions, but I do not claim that their opinions are not fair to me ! !

The ONLY on topic things were written by me, at Reply#43, of which the climber lobby picked up only the FIRST sentence ! And, of course, NOT A WORD, not even ONE, about anything else of the 5 next paragraphs of this post…

52

X., I presume that you attached the image of the
near/at-rupture state of the knot? Can you add the
one at the start --the “set”/start state?

Wow, what compression. And I see (in the final) that
the S.Part’s nip-grip of the eye legs likely has let less
of their forces return the favor (gripping, i.e.) to the
S.Part itself --an imbalance that grows, with tension.
One might wonder if the test specimen had been of
a frictive rope (and maybe of a less elastic one, too!)
would the same imbalance occur, or would perhaps
the eye legs get in some good grip on the S.Part so
that a different geometry obtained at later states?!

Thanks,
–dl*

53

I had just “frozen” the video, used Shift + PrintScreen keys to capture the image, and then I had “paste-ed” it in Paint, and saved it as .jpeg.

1.jpg

2.jpg

54

Of these nexTwo pics,
the top one shows a “weak form” fig.8, clearly indicated
by the tensioned S.Part pulled (down) away from the now
idle upper twin part.
Whereas the bottom image I think shows the “strong
form”, eye below and S,Part & tail (and it almost looks
to be a tightly bound trio of parts!?) above,
with the S.Part deeply pushed against and then even
past the thus-bulging-outwards (unloaded) twin part.

But neither of these shows a pre-loaded, hand-set
(I presume) knot state. I’m curious re that vis-a-vis
how much anticipation of the latter bearing-against
force can be done in setting hard the tail, so to leave
not enough material to give way to the S.Part’s
pressure (or not w/o a good fight that consumes
some force!). !?

Thanks again,
–dl*