International Guild of Knot Tyers Forum

General => Chit Chat => Topic started by: Mobius on April 17, 2015, 05:35:06 AM

Title: VET - Verifiable Easy Tieing
Post by: Mobius on April 17, 2015, 05:35:06 AM
We all know that a knot that is easily tied is a nice start to whether we actually use that knot, or not  :P

In the case of mountaineering that is one aspect, along with security, why a knot like the Retraced Figure 8 Loop (RF8L) is prevalent in climbing circles. The other main reason, I believe, is it's verifiability. Unfortunately, 'verifiable' means different things to different people in this context, so the term is at least somewhat subjective. ( http://igkt.net/sm/index.php?topic=5254.0 is where this was partially discussed recently).

I am not trying to invent a new acronym for the sake of it, however I feel that the worthiness of a knot, in term of it's verifiability, has generally been understated. I believe for a knot to be considered 'verifiable' it needs to exhibit some characteristic that is distinctive. For example, the difference between a Granny Knot and a Square Knot is one tuck, yet the distinctive interlacing of the 'collars' lets you see you have tied a Square Knot correctly. A Square Knot is VET I believe.

As a counter example: The difference between a Hunter's Bend and Zeppelin Bend is not so obvious (at least to me). I have tied a Zeppelin bend quite a lot, yet I can look at a picture of a Hunter's Bend and really have to inspect it rather closely to know the difference. In the case of the Zeppelin Bend and Hunter's Bend, mis-tying one for the other is probably not a big issue, however since these knots are easily confused, both these knots are not VET, in my mind. Of course, the mis-tying of a knot into it's 'look-a-like' could be quite a safety issue in other circumstances.

Is VET a useful concept (acronym)? Since VET seems to rank a lot more highly than PET in the case of the well respected RF8L, it might be a useful addition to think about when presenting a new knot. Your thoughts please.

Cheers,

mobius

[edit: fixed the spelling of 'zeppelin' and Hunter for Hunter's :-[ ]

Title: Re: VET - Verifiable Easy Tieing
Post by: roo on April 17, 2015, 07:22:48 AM
We all know that a knot that is easily tied is a nice start to whether we actually use that knot or not  :P

In the case of mountaineering that is one aspect, along with security, why a knot like the Retraced Figure 8 Loop (RF8L) is prevalent in climbing circles. The other main reason, I believe, is it's verifiability. Unfortunately, 'verifiable' means different things to different people in this context, so the term is at least somewhat subjective. ( http://igkt.net/sm/index.php?topic=5254.0 is where this was partially discussed recently).

I am not trying to invent a new acronym for the sake of it, however I feel that the worthiness of a knot, in term of it's verifiability, has generally been understated. I believe for a knot to be considered 'verifiable' it needs to exhibit some characteristic that is distinctive. For example, the difference between a Granny Knot and a Square Knot is one tuck, yet the distinctive interlacing of the 'collars' lets you see you have tied a Square Knot correctly. A Square knot is VET I believe.

As a counter example: The difference between a Hunter Bend and Zepplin Bend is not so obvious (at least to me). I have tied a Zepplin bend quite a lot, yet I can look at a picture of a Hunter Bend and really have to inspect it rather closely to know the difference. In the case of the Zepplin Bend and Hunter Bend, mis-tying one for the other is probably not a big issue, however since these knots are easily confused, both these knots are not VET, in my mind. Of course, the mis-tying of a knot into it's 'look-a-like' could be quite a safety issue in other circumstances.

Is VET a useful concept (acronym)? Since VET seems to rank a lot more highly than PET in the case of the well respected RF8L, it might be a useful addition to think about when presenting a new knot. Your thoughts please.

Cheers,

mobius
I agree with much of this, and it gets neglected too often.  I actually think the invention and slinging of acronyms is counterproductive.  It serves to hide the meaning.  You can just say that a knot is easily inspected or verifiable, or that it lacks evil impostors (http://notableknotindex.webs.com/glossary.html) (which have been another topic of discussion).

A knot can have benign impostors, too, by the way.  In the case of the Zeppelin Bend and the Hunter Bend, you have two secure knots.  The Hunter Bend is just jam prone, and the common method of tying the Zeppelin Bend makes it practically impossible to accidentally get the Hunter Bend anyway, so it's probably not the best case.  It's more common that instructions merely mislabel the knots out of ignorance.
Title: Re: VET - Verifiable Easy Tieing
Post by: agent_smith on April 18, 2015, 02:26:34 AM
Easy is a relative concept.

Indoor rock climbing gyms are (in my opinion) a very good place to start to examine the use of particular knots and their 'issues'.

If knots are used at indoor climbing gyms (which is an 'artificial climbing surface') it is almost without exception ABoK #1047 (Figure 8 eye knot). I disagree with the use of the term 'retraced figure 8' - because this merely describes the tying method. When a person has finished tying #1047, it has the same appearance and is identical in structure regardless of which method was used to tie it. In other words, the outcome is the same - its #1047.

Another point I'd like to make is the concept of the 'relic' knot. Any knots left in a rope will cause a retrievable abseil system to fail - it wont retrieve because the knot will jam at the anchor point. Therefore, when climbers untie the rope from their harness and attempt to retrieve it, if they inadvertently leave #524 (the so called relic knot) in the rope (or indeed any stopper knot), it will not retrieve. Several mountaineers have died (or been seriously injured) as a result of failure to retrieve their ropes during a multi-pitch abseil descent (directly or indirectly - as once they have lost or given up their ropes - they are forced to continue descending without the security of ropes. Note: There are several scenarios which could lead to ropes becoming stuck/jammed during a retrieval process and I wont go into details here...

Back to the indoor climbing gym... As you can imagine, all sorts of people from all sorts of backgrounds could walk into a climbing gym and sign up/pay for a climbing session. The staff have to teach/assess/confirm each and every customer how to use the facilities belay systems and to make sure that customers follow the gym 'rules'. Typically, ABoK #1047 is employed within the rope attachment to client harness interface (refer attached photo).

ABoK #1047 is a popular choice for the following principal reasons:

1. It is well entrenched within the culture of climbing in general (its been used and promoted for 50 years)
2. It has a proven track record - we know it works
3. People tend to parrot what they've been taught - it gets passed on from generation to generation
4. People tend not to stray far from what their original instructor taught them - they defend what they've learnt
5. Culture is hard to break - just look at any workplace with workers who've been there many years in the same job
6. Instructors favour (English spelling) teaching it...its relatively straight-forward to teach it
7. No special precautions need to be taken with the structure - compared to #1010 - you will die if no precautions are taken (eg securing the knot in some way)
8. Its secure and stable in all possible loading profiles in the context of climbing (eg you can fall upside down and the knot will still work) - you can also fall sideways and it still works.
9. And now for Mobius point.... it is easy to verify. Most instructors ask customers/students to look for parallel 'train tracks' when tying/forming the structure -and to leave a 200mm tail (8 inches for people who think imperial measures).
10. This last point is somewhat tricky - the legal aspects. It is easy to find wide-spread support for #1047. In a court case (think Americans and suing everyone in sight), I would not like to have to prove to a jury that my unique knot structure was equal to or better than the vanilla flavour #1047. I imagine I could argue my case - and I would need a very good lawyer (think $$$$). Also, most climbing gym owners/directors would not want to get too creative and allow exotic (and potentially untested) knot structures to be used at their workplace.

Climbers in general do not really care about the technical details of knots or ropes - they just wont to know that it works as advertised. IGKT members on the other hand - really like the technical details. I bought a great book a while back called 'How Apollo flew to the Moon' - it goes into great technical detail about how NASA actually pulled off its remarkable successes. Your average Joe on the street doesn't care about 'PAD' sheets and 'The State Vector' in steering a space craft. They just like to know that Armstrong and Aldrin planted the flag and left foot prints on the moon (unless you are one of those conspiracy theorists).

I like to tinker with my router and tweek the settings. Joe average internet user couldn't care less about routers or the 7 layer OSI model or how data is communicated in packets. I like to build my own PC computers and install my own software. Joe average computer user couldn't care less about what goes on 'under-the-bonnet'. They just want to know how to turn it on and then get on with having fun.

In the same way, Joe average climber couldn't care less about intricate alternative knot structures to #1047. Joe average climber generally goes-with-the-flow and uses what everyone else is using.

Time to stop typing now...

Mark

Title: Re: VET - Verifiable Easy Tieing
Post by: roo on April 18, 2015, 03:58:09 AM
Another point I'd like to make is the concept of the 'relic' knot. Any knots left in a rope will cause a retrievable abseil system to fail - it wont retrieve because the knot will jam at the anchor point. Therefore, when climbers untie the rope from their harness and attempt to retrieve it, if they inadvertently leave #524 (the so called relic knot) in the rope, it will not retrieve. Many mountaineers have died as a result of failure to retrieve their ropes during a multi-pitch abseil descent.
Can you provide citation of an actual case of someone leaving a figure eight loop partially untied which then caused the rope to become stuck upon retrieval leading to death?

For perspective, this chart (http://c535846.r46.cf2.rackcdn.com/anam_2007.pdf) reports a total of 1686 fatalities in mountaineering in the US and Canada for a recent 55 year period or a little over 30 a year on average.
Title: Re: VET - Verifiable Easy Tieing
Post by: xarax on April 18, 2015, 04:05:52 AM
  I disagree with the use of the term 'retraced figure 8' - because this merely describes the tying method.

  Correct ! However, "ABoK#1047" is like calling the Sheet bend as "ABoK#1" !  :)  For such a primordial knot, I do not see why we should use the Ashley s numbers... "Fig.8 loop" is OK. Perhaps "double line fig.8" ? ?
Title: Re: VET - Verifiable Easy Tieing
Post by: agent_smith on April 18, 2015, 07:04:53 AM
I'm not even going to dignify a full and detailed response to roos post questioning deaths resulting from climbers/mountaineers failure to retrieve their ropes.
You cant be serious in asking such a question!
I'll assume you're just trying to make some comment for your own self-gratification (or self importance). Nevertheless, to educate you roo, I modified my post to indicate that it could be direct or indirect causation - because once climbers lose or give up their ropes, they are then forced to continue without their ropes. Continuing without the security of a rope(s) obviously is a risky prospect. Getting down safely off a mountain without ropes is one thing, but crossing a glacier without ropes is just as serious and risky as the climb itself. Glaciers have many hidden crevasses. Imagine falling down a crevasse without the security of a rope... So back to deaths - all tragedies have a root cause. I would argue that losing ones ropes triggers a whole cascade of events which can (and do) lead to deaths in the mountains.
I'm going to assume that roo is not a climber and is ignorant of all that I write herein.

Mark
Title: Re: VET - Verifiable Easy Tieing
Post by: roo on April 18, 2015, 07:21:13 AM
I'm not even going to dignify a response to roos post questioning deaths resulting from climbers/mountaineers failure to retrieve their ropes.
You cant be serious in asking such a question!
I'll assume you're just trying to make some comment for your own self-gratification (or self importance).

Mark
I'm serious, and I do not ask for "self-gratification".  I'm giving you the chance to give evidence so we can examine the particulars of the situation.  That's all.  I'll gladly accept it should it surface. 

Please do not take offense. 
Title: Re: VET - Verifiable Easy Tieing
Post by: Mobius on April 18, 2015, 07:29:19 AM
   A property of a knot, which can be objectively defined ( and perhaps "measured", somehow, as well ) is the number of its slightly different "dressings". ( I say "slightly", because there are knots ( the "bi-stable" knots (1)), which can be "dressed" in so different, geometrically, ways, that they should be considered as different knots. )

I think verifying the correct dressing of a knot can be more subjective than verifying the correct structure of the knot in the first place :) For example, the nub of a knot can look quite different (and no doubt load differently) depending on what you tighten first when dressing.

  It seems that a knot which can be dressed in more than one ways, which ways, although slightly different, nevertheless can be a cause of some problem later, when/if the knot will be loaded heavily, is a knot that, of we can, we should better avoid.

I think that the two parts of verifying a knot have to be based on inspecting the knot prior to dressing it fully (ie. its loose predominantly 2D shape, that is hopefully fairly distinctive in some way) and then again when the knot is snug ready for use. That is what your link (1) showed I believe, though I could not get the Hunter s X Bend to look like the Pretzel-to-Pretzel Bend (I probably didn't try hard enough ;) )

  So, dressed in a one/single/singular form, would be a desirable, objective property of a knot, indeed.     

I think we could ruin just about any knot by finding a way to dress it badly. Some knots are able to be dressed quite loosely (a Zeppelin Bend for example) and it tightens to its best nub form all by itself under load (so I have read somewhere). Now that is a desirable quality.
Title: Re: VET - Verifiable Easy Tieing
Post by: Mobius on April 18, 2015, 08:03:04 AM
Easy is a relative concept.

Indoor rock climbing gyms are (in my opinion) a very good place to start to examine the use of particular knots and their 'issues'.

If knots are used at indoor climbing gyms (which is an 'artificial climbing surface') it is almost without exception ABoK #1047 (Figure 8 eye knot). I disagree with the use of the term 'retraced figure 8' - because this merely describes the tying method. When a person has finished tying #1047, it has the same appearance and is identical in structure regardless of which method was used to tie it. In other words, the outcome is the same - its #1047.

Another point I'd like to make is the concept of the 'relic' knot. Any knots left in a rope will cause a retrievable abseil system to fail - it wont retrieve because the knot will jam at the anchor point. Therefore, when climbers untie the rope from their harness and attempt to retrieve it, if they inadvertently leave #524 (the so called relic knot) in the rope (or indeed any stopper knot), it will not retrieve. Several mountaineers have died (or been seriously injured) as a result of failure to retrieve their ropes during a multi-pitch abseil descent (directly or indirectly - as once they have lost or given up their ropes - they are forced to continue descending without the security of ropes. Note: There are several scenarios which could lead to ropes becoming stuck/jammed during a retrieval process and I wont go into details here...

Back to the indoor climbing gym... As you can imagine, all sorts of people from all sorts of backgrounds could walk into a climbing gym and sign up/pay for a climbing session. The staff have to teach/assess/confirm each and every customer how to use the facilities belay systems and to make sure that customers follow the gym 'rules'. Typically, ABoK #1047 is employed within the rope attachment to client harness interface (refer attached photo).

ABoK #1047 is a popular choice for the following principal reasons:

1. It is well entrenched within the culture of climbing in general (its been used and promoted for 50 years)
2. It has a proven track record - we know it works
3. People tend to parrot what they've been taught - it gets passed on from generation to generation
4. People tend not to stray far from what their original instructor taught them - they defend what they've learnt
5. Culture is hard to break - just look at any workplace with workers who've been there many years in the same job
6. Instructors favour (English spelling) teaching it...its relatively straight-forward to teach it
7. No special precautions need to be taken with the structure - compared to #1010 - you will die if no precautions are taken (eg securing the knot in some way)
8. Its secure and stable in all possible loading profiles in the context of climbing (eg you can fall upside down and the knot will still work) - you can also fall sideways and it still works.
9. And now for Mobius point.... it is easy to verify. Most instructors ask customers/students to look for parallel 'train tracks' when tying/forming the structure -and to leave a 200mm tail (8 inches for people who think imperial measures).
10. This last point is somewhat tricky - the legal aspects. It is easy to find wide-spread support for #1047. In a court case (think Americans and suing everyone in sight), I would not like to have to prove to a jury that my unique knot structure was equal to or better than the vanilla flavour #1047. I imagine I could argue my case - and I would need a very good lawyer (think $$$$). Also, most climbing gym owners/directors would not want to get too creative and allow exotic (and potentially untested) knot structures to be used at their workplace.

Climbers in general do not really care about the technical details of knots or ropes - they just wont to know that it works as advertised. IGKT members on the other hand - really like the technical details. I bought a great book a while back called 'How Apollo flew to the Moon' - it goes into great technical detail about how NASA actually pulled off its remarkable successes. Your average Joe on the street doesn't care about 'PAD' sheets and 'The State Vector' in steering a space craft. They just like to know that Armstrong and Aldrin planted the flag and left foot prints on the moon (unless you are one of those conspiracy theorists).

I like to tinker with my router and tweek the settings. Joe average internet user couldn't care less about routers or the 7 layer OSI model or how data is communicated in packets. I like to build my own PC computers and install my own software. Joe average computer user couldn't care less about what goes on 'under-the-bonnet'. They just want to know how to turn it on and then get on with having fun.

In the same way, Joe average climber couldn't care less about intricate alternative knot structures to #1047. Joe average climber generally goes-with-the-flow and uses what everyone else is using.

Time to stop typing now...

Mark

A very interesting post thank you Mark.

I have not had time to digest this post fully yet, however I think one inference I can draw from it is that though PET is an issue with #1047 (I am not good with Ashley's numbers, maybe I should buy that book :) ) it does not override the proven historical and largely successful use of the knot in general. Not yet, anyway. Verification is one part of it's continued use, however it is not a 'verification' vs 'PET' issue as I probably portrayed it.

Many mountaineers have died as a result of failure to retrieve their ropes during a multi-pitch abseil descent.

This is a real worry though. I am definitely thinking PET from now on.

Cheers,

mobius
Title: Re: VET - Verifiable Easy Tieing
Post by: Dan_Lehman on April 18, 2015, 08:24:09 AM
I'm not even going to dignify a full and detailed response to Roo's post questioning deaths resulting from climbers/mountaineers failure to retrieve their ropes.
You cant be serious in asking such a question!  ...
This doesn't put your assertion in good standing, then.
I've been reading rockclimbing forum chatter for a long
time, and I don't recall discussion of issues with "relic knots"
--but I do know that the fig.8 eye knot is the the common
and commonly recommended method (usually in contrast
to the bowline).

And if you just think about the alleged circumstance,
you'd question even the gravity of the situation --not good,
but ... so grave?  After all, if the relic knot in one END of
the line jams at the rappel rings (or whatever) at the TOP,
you will at least have about half of the line retrieved below,
from which a climber could be belayed to climb up to free
the jam (the orientation of the line, then, would be sort
of upside-down vs. the abseiling situation --both ends
at the top, center point at the bottom w/belayer).

Now, some difficulty, even failure, to retrieve ropes on
account of the bulk and snagging of an end-2-end knot
joining abseil lines (the usual situation : a climbing rope
is tied to another or a haul line to make a full-length
abseil twin line).

Quote
I disagree with the use of the term 'retraced figure 8'
--because this merely describes the tying method.
When a person has finished tying #1047, it has the same appearance
and is identical in structure regardless of which method was used to tie it.
In other words, the outcome is the same - its #1047.
I used to hold a similar position on knot names, and on
this case in particular --to find it so stupid that two of our
kermantle-rope testers (viz., Dave Richards, & James Frank
(CMC Rope Rescue Manual)) included each such knot
in their testing (and, yes, got similar results)!!

ORRR, one can realize that in fact the assertion of getting
the same knot is something that can be empirically tested:
do the commonly applied two methods really have the same
result, in practice?!  --yes, in theory, except that you must
realize that this knot is NOT carefully specified (such as which
end bears load --and #1047's presentation is a case in point)!
Conceivably, an empirical study could find that the tying method
results in a difference, often.  (That said, there have been some
tests of haphazardly tied fig.8s showing somewhat common results.)


--dl*
====

Title: Re: VET - Verifiable Easy Tieing
Post by: Mobius on April 18, 2015, 09:31:53 AM
....
do the commonly applied two methods really have the same
result, in practice?!  --yes, in theory, except that you must
realize that this knot is NOT carefully specified (such as which
end bears load --and #1047's presentation is a case in point)!

This is why I think a 'so-called' TIB knot needs to be loadable from both ends. If a knot is loadable 'S-part only', then that knot does not deserve a TIB status in my opinion. If a knot is tied TIB, then nobody wants to be playing "Eeny, meeny, miny, moe" about which end to load in a critical situation!

Cheers,

mobius
Title: Re: VET - Verifiable Easy Tieing
Post by: Mobius on April 18, 2015, 12:49:36 PM
Find an acronym !  :) ( in addition to the TIB-ness, which is OK, just something less of what you demand).

 ;D No-one seemed to like my VET invention... so I think I will leave acronyms alone for awhile ;D  With that in mind, maybe we can just try and talk about 'TIB-ness' in terms of either-end loading for some critical applications?

Cheers,

mobius
Title: Re: VET - Verifiable Easy Tieing
Post by: Dan_Lehman on April 20, 2015, 04:33:42 AM
I think a 'so-called' TIB knot needs to be loadable from both ends.
If a knot is loadable 'S-part only', then that knot does not deserve a TIB status in my opinion.

   A knot is TIB when it can be tied in-the-bight, period.  ...
   An example : you may have a long line, and you may need to tie a bowline in the middle of it, ...
+1, well put.
Throwing in an eye (or maybe a hitch) without need for
fetching the tail of the line can be a Good Thing !!

Now, one might insist that any mid-line eyeknot be TIB
but one shouldn't conclude that all are --there might be
situations that benefit from a knot that must be tied with
ends (but done once and thereafter resident in the line for
whatever function finds it so appealing).

--dl*
====
Title: Re: VET - Verifiable Easy Tieing
Post by: agent_smith on April 22, 2015, 10:36:54 AM
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.

Climbers/mountaineers have long appreciated and understood the notional concept of 'verifiable' - even though they may never have documented (or thought in terms of) that word as such.

As I already pointed out, indoor climbing gyms are an excellent place to start looking for answers - there would be a huge volume of customers passing through climbing gyms all over the world every year. Nearly all of these customers would have to know how to attach a climbing rope to their harness. The knot most favoured is #1047 (Figure 8 connective eye knot). Although I don't have actual hard statistics for you, I can say with reasonable certainty that #1047 is the preferred knot.

If we accept this as fact for a moment - then we can ask the question the question; "Why #1047"?

It is my personal view that (one of) the key reasons #1047 is preferred is because it is easy to verify. The structure has 2 key patterns:
1) It takes the form of the numeral 8; and
2) It has the appearance of parallel train tracks (which twist about in the form of the numeral 8.
There are other reasons too... such as 'proven reliability' - we know it works. And the vast majority would support its use - and therefore you have the general backing of the climbing community as a whole.

There are 2 indoor climbing gyms in my home town and both use and rely heavily on #1047.

The other type of adventure activity which also tends to rely on #1047 is 'challenge ropes courses'. Go here for some background info: http://en.wikipedia.org/wiki/Ropes_course

It might be worth your while to make contact with a local indoor climbing gym and ask the owner/proprietor what type of connective knot they use at their facility (and why). I would also be keen to find out the results of your inquiries (if you choose to do so). Would be good to get an outside perspective...i would suggest that you don't say anything about the concept of 'verifiable' - because that would 'bait' them and you would receive corrupted feedback.

Something else I'd like to point out: Knot strength is nonsense - what matters most is stability and security. I usually cringe when I see people in various forums on the internet discussing and comparing knots based on strength. Its a pure fiction. As far as I am aware, no tie-in knot has ever simply catastrophically failed on account of reaching its ultimate tensile strength in a lead climbing fall. I would argue that knots 'fail' on account of poor stability and/or poor security. Which brings me to the so-called 'Euro death knot'. There is an incredible amount of what I refer to as bullshit about ABoK #1410 - when in reality, its the offset figure 8 bend (no ABoK number available) that is the likely culprit. Anyhow,  if you ask indoor climbing gym owners why they choose a particular tie-in knot - if they start quoting % strength figures you can safely ignore it. Try to obtain additional info apart from just strength.

I'd like to add the concept of 'verifiability' to my knot study guides because I think it is a concept that has merit.

Mark

Title: Re: VET - Verifiable Easy Tieing
Post by: xarax on April 22, 2015, 04:41:16 PM
   It would be interesting if you make a poll, and ask the members of the indoor climbing gyms in your home town 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 !  :) 
Title: Re: VET - Verifiable Easy Tieing
Post by: roo 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.
Title: Re: VET - Verifiable Easy Tieing
Post by: Dan_Lehman 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*
====
Title: Re: VET - Verifiable Easy Tieing
Post by: Dan_Lehman 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*
====
Title: Re: VET - Verifiable Easy Tieing
Post by: xarax 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 )
Title: Re: VET - Verifiable Easy Tieing
Post by: Dan_Lehman 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*
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Title: Re: VET - Verifiable Easy Tieing
Post by: xarax 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 !  :)
Title: Re: VET - Verifiable Easy Tieing
Post by: Mobius 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*
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 :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]
Title: Re: VET - Verifiable Easy Tieing
Post by: roo 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 (http://notableknotindex.webs.com/spanloop.html) 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 (http://notableknotindex.webs.com/pilehitch.html) is one of the most underutilized knots of all time.
Title: Re: VET - Verifiable Easy Tieing
Post by: Mobius on April 24, 2015, 10:56:19 AM
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   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.

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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
Title: Re: VET - Verifiable Easy Tieing
Post by: Dan_Lehman 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.)

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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*
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Title: Re: VET - Verifiable Easy Tieing
Post by: Mobius 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
Title: Re: VET - Verifiable Easy Tieing
Post by: roo 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 (http://notableknotindex.webs.com/gnathitch.html) 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.
Title: Re: VET - Verifiable Easy Tieing
Post by: Dan_Lehman 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 (http://notableknotindex.webs.com/gnathitch.html) 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*
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