Author Topic: VET - Verifiable Easy Tieing  (Read 6197 times)

roo

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Re: VET - Verifiable Easy Tieing
« Reply #15 on: April 22, 2015, 07:32:59 PM »
Quote
No-one seemed to like my VET invention...

Mobius - I like the concept because it does indeed already have real-world application.

I like the 'verifiable' part - but no so much in favour of the concept of 'easy tieing' part.

Easy 'tieing' is a relative concept - whats easy for me or you may not be so easy for another.
I think Mobius was referring to people not liking the use of the acronym.  There has been nearly universal support for knots being verifiable or easily inspected both here and on various knotting websites, including my own.  I could imagine ways to measure it in a lab setting with volunteers and a series of properly and improperly tied knots, but it is probably not worth that level of effort.

Ease of tying can actually be measured quite simply.  Use a stopwatch and generate average times to tie or untie with a number of trials.  If a knot is difficult to tie correctly for a given application, then it'll likely take more time to execute, or it will generate errors that will cause the tyer to have to untie the mess (as seconds tick away) and try again (tick, tick, tick).

It may not be a 100% perfect measurement, but it is certainly better than mere opinion or judging by geometry.  Another pointless acronym can be abandoned (look ma, no acronyms left!).  The only thing that may not be captured is if a knot is fast to tie correctly but is maybe less than ergonomic to tie.


P.S.  I would include the time it takes for adjustment of the knot's position or free end lengths and adequate dressing.  Time starts when you touch the rope and time ends when you are ready to use the finished knot with no further tinkering.
« Last Edit: April 24, 2015, 04:15:06 PM by roo »
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Dan_Lehman

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Re: VET - Verifiable Easy Tieing
« Reply #16 on: April 23, 2015, 05:25:36 PM »
;D No-one seemed to like my VET invention...
Firstly, it's too like 'PET' --just an initial character
difference--; that's reason enough not to like it.

--dl*
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Dan_Lehman

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Re: VET - Verifiable Easy Tieing
« Reply #17 on: April 23, 2015, 05:33:09 PM »
   It would be interesting if you make a poll,
and ask the members of the indoor climbing gyms in your home town ...
THIS "asking" would be better as a complement
to first having examined and recorded how they
actually tie the knot --there would be the potential
to discriminate between practice & awareness/belief
(and, what is tied is what matters)!

Quote
... which knot of the two shown in the attached pictures is the "correct",
properly dressed fig.8 knot ( bend or loop ) ... :) :)
This is another wager - if the "wrong" answers are more than 5% of the total, I win !
   Noope, the proper dressing of the fig.8 bend and loop is not easily tiable,
nor easily verifiable. My theory is that people tie it, because it is such a beautiful knot !  :)
I'm thinking that "neither" is the correct answer.
And that it's arguably a different answer depending
upon eye-knot or end-2-end knot.  (There might
even be further discriminating factors.)
And I note that which-end-is-loaded is undefined,
which confounds the evaluation of a choice.


--dl*
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xarax

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Re: VET - Verifiable Easy Tieing
« Reply #18 on: April 23, 2015, 05:46:10 PM »
  I'm thinking that "neither" is the correct answer.

  Do you work up your sight, memory or your muscles in an indoor climbing gym ?  :)
  I was not asking you ! You had already replied - well, in your way  :
  http://igkt.net/sm/index.php?topic=2198
  where you may see the correct answer ( also shown in the attached picture )
« Last Edit: April 23, 2015, 05:48:24 PM by xarax »
This is not a knot.

Dan_Lehman

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Re: VET - Verifiable Easy Tieing
« Reply #19 on: April 23, 2015, 06:54:35 PM »
  I'm thinking that "neither" is the correct answer.

  Do you work up your sight, memory or your muscles in an indoor climbing gym ?  :)
  I was not asking you ! You had already replied - well, in your way  :
  http://igkt.net/sm/index.php?topic=2198
  where you may see the correct answer ( also shown in the attached picture )
Thank you for this 3rd choice, which indeed reflects
my so-called "perfect form" --and where I see "best"
 (or, rather, "strongest" which might not be best
  for some circumstance vs. "morEasily untied" ...)
as loading the left white strand (vs. right orange or
both, if eye knot).  Note that Dave Merchant, author
of "Life on a Line" advocates what you show above
in your first/top image, loaded on orange-left ... .

In my observations, the eyeknot will see the symmetry
started by this "perfect form" broken when the eye bight
legs make their turn around the S.Part, and they slip out
of it --likely a coercion of torsion, in part.  One can often
see that it's the orange left-side end that is loaded
by how this *inner* twin part is drawn so tightly, and
the white twin is left rather untensioned out beyond it
--an easy "tell" to observe.

--dl*
====
« Last Edit: April 23, 2015, 06:56:49 PM by Dan_Lehman »

xarax

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Re: VET - Verifiable Easy Tieing
« Reply #20 on: April 23, 2015, 07:32:40 PM »
   I had used this trick with those two ( of the three plus one, in total, possible ones ) symmetric but not "perfect" forms of the fig.8 bend, just to show that the fig.8 loop ( and bend, for that matter ) is neither easily verifiable ( regarding the "correct"/"perfect" dressing ), nor easily tied, in the first place. If knot tyers can not distinguish or agree on the differences, what can the "average" knot user do, in his indoor climbing gym ?  :)
   That is why I claim that the fig.8 loop is chosen by the general public because it has not many drawbacks ( although it may become difficult to untie after heavy loading, and it is not PET ) AND it is beautiful - and that, to chose by taking into account higher values, is a plus, among the many minus of the human race !  :)
This is not a knot.

Mobius

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Re: VET - Verifiable Easy Tieing
« Reply #21 on: April 24, 2015, 04:07:35 AM »
;D No-one seemed to like my VET invention...
Firstly, it's too like 'PET' --just an initial character
difference--; that's reason enough not to like it.

--dl*
====

 :o LOL, I can think of better reasons than that why both PET and TIB are acronyms that could be disliked. "V" and "P" are really so confusing?

As for TIB and either-end loading. What is the point of having a loop knot that is TIB and cannot be loaded safely from either end? That is potentially a much bigger safety issue than having a relic knot in non-PET knots. Maybe most TIB loops are able to be loaded safely from either-end anyway, though one would need to look at that case by case.

Cheers,

mobius

[edit: fixed a typo]
« Last Edit: April 24, 2015, 08:28:30 AM by mobius »

roo

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Re: VET - Verifiable Easy Tieing
« Reply #22 on: April 24, 2015, 06:04:22 AM »
What is the point of having a loop knot that is [tied on-the-bight] and cannot be loaded safely form either end?
It certainly reduces the general appeal of such a loop.  Some may be willing to tolerate it because a given knot offers some other benefit in return.  For example, a Span Loop is more stable in one direction than another, but it offers very nice ease of untying.  In a general utility, non-life-threatening situation where the tyer knows the best way to load it, it may well fit the bill.

Quote
That is potentially a much bigger safety issue than having a relic knot in non-PET knots.
Agreed.

Quote
Maybe most [tied on-the-bight] loops are able to be loaded safely from either-end anyway, though one would need to look at that case by case.
Since there are such a large number of them, I would hesitate on percentages.  However, there aren't too many tied on-the-bight loops that handle various load paths, are easy to tie and inspect, resist jamming, and have decent security and stability.  The very act of limiting knots to geometry tied on the bight severely reduces the number of available knots.  If you find something to rival the likes of the Butterfly Loop for example, that would be a notable accomplishment.

edit:  P.S.  Don't forget to look to hitches that can be tied on the bight.  They can often replace loops just fine.  The Pile Hitch is one of the most underutilized knots of all time.
« Last Edit: April 24, 2015, 03:11:19 PM by roo »
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Mobius

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Re: VET - Verifiable Easy Tieing
« Reply #23 on: April 24, 2015, 10:56:19 AM »
Quote
   When a knot tyer ties a TIB knot in the middle of the line, he knows which of the two parts of the line will become the " Standing" and which the "Tail End

Are you sure? I am not a mountaineer (as I have said before), however is it so implausible for a tired climber to grab the "wrong end" of his just tied TIB knot and hence load the "wrong end" in some critical situation? Maybe no-one has died choosing the "Tail End", however that might be because there was not a "wrong end" to choose from in the first place. Is this not one of the great strengths of an Alpine Butterfly Loop: it's ability to be either-end loaded? Or both ends simultaneously, for that matter?

Quote
2. Perhaps. In a hurry, or when you can not follow the two ends of the knot to see which goes where, you may tie a loop with the wrong orientation.

Yes  :) Or (as another example), the two ends cross one another as they exit the collar of a bowline and the climber doesn't notice and grabs the wrong one to load. Better to simply avoid that possibility altogether and know that both ends can be loaded safely in the first place.

Quote
3. No, they are not ! Neither most of the loops that are tied most times by most people, nor most of the loops that most people know.
   Of course, "safety" is a word with such a broad spectrum of meanings... A knot that will not slip, but still will be severely/badly deformed, and literally re-dressed after a "wrong"-end loading, is not a "safe" knot, IMO - because those two different, geometrically, forms are, in fact, two different variations of the knot, which, generally, will not have the same strength. Now, even  f you believe that the strength of knots is "irrelevant", there is another thing to consider : the one form may be easily untiable after heavy loading, and the other may jam - and that is, in fact, a very common situation. Many secure bowlines, on which the collar structure has an overhand or fig.8 knot form, are difficult to untie even when they are loaded by the "right" end, so imagine what happens when they will be loaded by the "wrong" end...   

   I want to repeat that EEL ( either end loading ) is a useful feature, which increases the versatility of a loop.

I think it's a pity that PET (post-eye-tiable) implies a one-stage tying process that will not leave a relic knot, yet TIB (tiable-in-the-bight) just means that and no more, and too bad if the knot created isn't particularly safe in some circumstances. EEL (either-end-loading) might be useful acronym I guess, though it is a shame TIB did not encompass that idea in the first place.

Quote
   The other thing you have proposed, the "verifiability" feature, does not make much sense - except as I had tried to explain : if it means that the knot can only be tied in a single, almost self-dressing form, so, during its tying, it will not require much attention from the part of the knot tyer. He would only have to set up the knot in a way that will be topologically correct. Then, the dressing will be easy, and it will always lead to the same geometrical form.

Verifiability makes a lot of sense. That a knot has some visible features that give the knot tyer quite some confidence he/she created the right knot is important. Like some other terms used frequently in the knot world, verifiability is not an absolute. So what? Neither are terms like 'security' and 'strength'. It does not mean that 'verifiability' is not a very useful concept to work with.

Cheers,

mobius
« Last Edit: April 24, 2015, 11:07:27 AM by mobius »

Dan_Lehman

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Re: VET - Verifiable Easy Tieing
« Reply #24 on: April 24, 2015, 08:33:36 PM »
;D No-one seemed to like my VET invention...
Firstly, it's too like 'PET' --just an initial character
difference--; that's reason enough not to like it.

--dl*
====

... "V" and "P" are really so confusing?
Not "so", but they are, of the string, alone as diff.s;
and then the common "ET" has to assume
different meanings per this initial-character difference.
(You could run some by-sight-reading test of the
confusion.)

Quote
As for TIB and either-end loading.
What is the point of having a loop knot that is TIB and cannot be loaded safely from either end? That is potentially a much bigger safety issue than having a relic knot in non-PET knots. Maybe most TIB loops are able to be loaded safely from either-end anyway, though one would need to look at that case by case.
X. & I have given a purpose : to quickly put in
a fixed eye w/o fetching the end of a possibly long
or even end-not-available line.  And one will darn
well know which end gets loaded by obvious elements
in the tying --it will be that end going to where one
has need, and not the one lying out of reach.
I've used the ability in doing stress-testing of knots,
tying off a side that runs too long after the initial
loading which compressed the knot and stretched
things so that I now need to "choke up" in order to again
step on my pulley and deliver another load (without
running down to ground) !

You make it sound as though the knot tyer is completely
divorced from her action --like flipping a coin.  This isn't
a common (or desirable) circumstance; yes, one can want
to guard against cases of fatigue or bad conditions --and
in rockclimbing, late-done abseils come to mind, and hence
the recommendation for the simple, "EDK"/"offset water knot",
maybe w/one tail tied off around the other.  --which, alas,
yields the irony/double-edged aspect : if tying off this tail
around the other is right, is the other way wrong, and thus
a potential pitfall?  --ditto re orientation of thicker & thinner
lines (often the case) being joined : there is a preferable way
which should give enhanced resistance to flyping; and thus
an inferior way which must increase that vulnerability (alas).
.:. We don't have the better without the bitter. 
.:. For brain-dead doing, a simple full "EDK" back-up works,
giving no strand-distinction to make; just do A and Repeat!
(and damn that "leave long tails" advice --DO SOMETHING
in the tails!).

Now, for some accepted >>mid-line eye-knots<<,
there are preferable loadings; e.g., in the knots
corresponding to Ashely's #1408/1452, on eye leg
makes a full turn through the central nipping space
before collaring one end --and it's that end that should
be unloaded if one-sided loaded, as its collar is thus
protected from being drawn tight (whereas the S.Part
end in this case will keep its collar drawn open, unable
to collapse).  Yes, there have been some complaints
that the butterfly can be hard to untie, for this reason.
And this complicates the tying a bit; I've not put to memory
the method so as to get the desired effect (but have some
slight sense that going so goes against what would be
easier for eye-sizing/-placement, alas).

Quote
Is this not one of the great strengths of an [Alpine] Butterfly Loop :
 it's ability to be either-end loaded?
Or both ends simultaneously, for that matter?
ExampLEsSpeculation [<= word-fusion speak :-] doesn't get us far.
I can't think of a climbing situation in which this
is an issue.  That said, anecdotal evidence says that
some climbers have mistaken "long tails" qua abseil
lines and clipped into them(!!).

As for the butterfly, it's interesting to note test
results in the CMC Rope Rescue Manual (3rd? ed.) which
shows (some orientation of ...) the fig.8 eyeknot stronger
in both end-2-eye loading and end-2-end (offset) loading
than the knot supposedly so good at the latter!  YMMV,
but we can recall Agent_Smith's reminder that "knots don't
break" in the history of climbing.


--dl*
====

Mobius

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Re: VET - Verifiable Easy Tieing
« Reply #25 on: April 25, 2015, 01:17:18 AM »

You make it sound as though the knot tyer is completely
divorced from her action --like flipping a coin.  This isn't
a common (or desirable) circumstance; yes, one can want
to guard against cases of fatigue or bad conditions --and
in rockclimbing, late-done abseils come to mind,...

I am simply advocating that climbers have a well constructed knot that guards against "fatigue or bad conditions". That is not making it sound like I am 'divorcing' climbers from their actions.

Quote
Quote from: mobius
Is this not one of the great strengths of an [Alpine] Butterfly Loop :
 it's ability to be either-end loaded?
Or both ends simultaneously, for that matter?
Quote from: Dan_Lehman
ExampLEsSpeculation [<= word-fusion speak :-] doesn't get us far.
I can't think of a climbing situation in which this is an issue. 

Now, what does Geoffrey Budworth have to say on this matter:
Quote from: Budworth, "The Complete Book of Knots", Page 86
ALPINE BUTTERFLY

APPLICATIONS
This fixed loop is tied in the bight of a rope and is clipped into by the middle climber in a team of three. It can be pulled in two (or even three!) directions at once without distorting or capsizing. It can also permit the temporary use of damaged rope, by isolating a flawed section within the loop.

That looks like two good reasons to me and Budworth must share my "word-fusion speak" too   :)

Cheers,

mobius

roo

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Re: VET - Verifiable Easy Tieing
« Reply #26 on: April 25, 2015, 01:49:36 AM »
Quote from: Budworth, "The Complete Book of Knots", Page 86
ALPINE BUTTERFLY

APPLICATIONS
This fixed loop is tied in the bight of a rope and is clipped into by the middle climber in a team of three. It can be pulled in two (or even three!) directions at once without distorting or capsizing. It can also permit the temporary use of damaged rope, by isolating a flawed section within the loop.

That looks like two good reasons to me and Budworth must share my "word-fusion speak" too   :)
Another example comes to mind:  If you want to make a Y-shaped double anchor system with a single rope, you can tie a long butterfly loop for one arm, and leave a longish tail from the loop for the other arm (terminating with perhaps some other hitch or loop).  All parts see tension.

It uses less line than a double loop, and avoids some of the quirky instabilities of common double loops.
« Last Edit: April 25, 2015, 01:50:40 AM by roo »
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Dan_Lehman

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Re: VET - Verifiable Easy Tieing
« Reply #27 on: April 25, 2015, 02:45:23 AM »
Another example comes to mind:  If you want to make a Y-shaped double anchor system with a single rope, you can tie a long butterfly loop for one arm, and leave a longish tail from the loop for the other arm (terminating with perhaps some other hitch or loop).  All parts see tension.

It uses less line than a double loop, and avoids some of the quirky instabilities of common double loops.
But it is a case of just one loading qua eye knot
--from eye attachment downwards, and not to the
short end (which would need to fail solo load the eye).
And so, one could use a TIB knot w/bias in favor of one
such eye loading (yes, w/further needs to support the
*offset* 2nd-/Y-end loading --which shares opposition
to the other end, not to the eye).
(Whereas in the middleman situation,
 the loading could be in either direction.)

But it is a wild, gratuitous stretch to impose such
constraints of operation on every TIB knot, or to
slight those failing the full set of loadings; there
are needs well served by these, for which anything
more is devoid of merit.


--dl*
====