International Guild of Knot Tyers Forum

General => Chit Chat => Topic started by: Tangled on August 10, 2015, 10:45:24 PM

Title: Ashley knot security tester
Post by: Tangled on August 10, 2015, 10:45:24 PM
With all the talk about the properties of the many bowline variants, I'm curious if anybody has built  an Ashley knot security tester (ABok#63, page 16), or something of a similiar nature.  If so, what weight, height of drops, and cord did you use? 

I am very curious to see how various knots would perform with commonly available utility cordage.  By this I mean the braided nylon rope sold at most hardware and truck rental places, 550 cord, polypropelene truck rope, foam core diamond braid, &c.  IIRC, Ashley used Mohair yarn for his testing, which is a very different animal then what most of us use today..

"One accurate measurement is worth a thousand expert opinions."
―Rear Admiral Grace Hopper, USN
Title: Re: Ashley knot security tester
Post by: roo on August 11, 2015, 01:44:15 AM
With all the talk about the properties of the many bowline variants, I'm curious if anybody has built  an Ashley knot security tester (ABok#63, page 16), or something of a similiar nature.  If so, what weight, height of drops, and cord did you use? 

I find that in real life use, knots in rope tend to have the most difficulty staying tied when they are subject to slack shaking rather than weight drops.
Title: Re: Ashley knot security tester
Post by: Tangled on August 11, 2015, 03:31:15 AM
Are you talking about a "Flapping in the wind" type loadcase?
Title: Re: Ashley knot security tester
Post by: roo on August 11, 2015, 04:41:05 AM
Are you talking about a "Flapping in the wind" type loadcase?
Such motion could come from wind, but it can also be human or wave generated.
Title: Re: Ashley knot security tester
Post by: Dan_Lehman on August 11, 2015, 07:47:21 AM
Quote
IIRC, Ashley used Mohair yarn for his testing,
which is a very different animal then what most of us use today..
Recall further that he used this because he was tasked
to find knots that worked in it --not that he thought it
somehow a reasonable material for knots testing.  It
should be pointed out that *knots* as abstract entities
lack physical properties, and one should be thinking of
"<this_material knotted>" in considering physical aspects.

As for "flapping in the wind", that even puts more load
on a knot than what might be of concern w/security.
I have various small cords attached to my keys cord
and I find that most knots work loose in my pocket,
with a notable exception being the zeppelin-knotted
ends of a small binding cord (a hollow braid of nylon),
where the tails are minimally short and *blossomed*
so that they cannot be pushed and also serve to some
degree qua stoppers --that end-2-end knot has been
tied for years, even decade(s)?! !!  (But another such
knot tied in ends of 3/16" solid braid nylon cord on this
collection of stuff in my pocket was pretty quickly too
loose!  (Moderately tightened grapevine bends have
loosened, also.)

I've mused about some run-'em-up-the-flagpole testing
of security in a breeze, or using vibrations of some
machine (washer?); the test would largely be one of
Pass/Fail : begin and run it continuously for a period
and see what's still tied when it's over.


--dl*
====
Title: Re: Ashley knot security tester
Post by: Dan_Lehman on August 11, 2015, 07:18:53 PM
using vibrations of some machine (washer?);

   ! ! :) :) Good idea.
   You should attach the knot to the limbs of a small bow,
which will keep the ends tensioned,
and see if it will come out in one piece after the washing ( and drying ! )... :)
But I don't want the ends tensioned --I want to test
"slack security", resistance to shaking/jostling/idle_loosening.

And so my thought re the machine was to have a series
of knotted specimens tied to a rigid pole, dangling, and
being shaken by the machine's vibrations transferred
via the pole (or, via flag-shaken line to which specimens
are attached, similarly --but where to put one's monetary
tokens to generate a breeze?!   :P  ).

Hmmm, thinking of my in-the-pocket non-testing but
effectively a sort of testing ... , I can thus suggest that
one has a bag of speciments, perhaps also weighted balls,
that one repeatedly lets roll down a slope
--the point being
to mimic my in-the-pocket circumstance, and to use what
CAN be depended upon --a slope (which won't change angle,
alter gravity, or move away, time to time!).  The "weighted"
(better, maybe, "weighty" ?) balls are there to help ensure
that this bag o' knots does roll down the slope, while also
providing some additional "jostling" effect internally?
(maybe just one old bowling ball!).

And grading would be pretty coarse --as befits this quite
non-finely-graduated test-- : do the knots stay tied?
--or loosen but only up to a point?  --or only in some
of the materials?  --... some of the settings?  et cetera.

[Currently, I'm awarding myself Bright Idea of the Week for this!]
[[note : award precedes actual attempt to DO ... ! ]]
 :)


--dl*
====
Title: Re: Ashley knot security tester
Post by: Tangled on August 11, 2015, 09:21:52 PM
If you've got a steady breeze, just tying the knot in the middle of a lead and running it up a flagpole or hanging it off a clothesline might do the trick.  Figure one knot per lead, and multiple leads per test.  If you don't have a breeze, you can always run a bungee across the interior of your car trunk, tie the leads onto that, and check the knots after a commuting for a few days. 

As far as knots staying put long term, in the days or yore, I believe that the knots were painted with pine tar.  I fix them by either sewing (sailmaker's whipping), Serving (bowstring serving), Saturating (diluted PVA glue), or sticking (injecting glue into the heart of the knot). 

EDIT: If you want to use a washing maching or dryer, just stick everything into a mesh delicates bag and toss it into with the next load.  No jigs required.  Just beware of color bleeding.

http://www.amazon.com/Mesh-Lingerie-Delicates-Wash-Bag/dp/B0001E83AE

Tossing a bag full of paracord in a hot water load is fairly common way to prep it (pre-shrink and soften) for outdoor use.
Title: Re: Ashley knot security tester
Post by: Dan_Lehman on August 12, 2015, 05:55:46 PM
There is going to be a difference in knot-loosening (or not)
between the in-the-pockets-like full slackness and just
lightly weighted (the material ends have mass) ropes
somehow being tensioned sufficiently to be shaken
--in which case, I can't see the S.Parts of such knots
ever working their way into the knot as part of
the loosening, which can occur with the other method.
And, so, what does one want to test?
  (--perhaps both, and more : full loading has shown lack
   of security in common kernmantle ropes & knots (e.g.,
   the Dave Richards testing in which sheet bend /fisherman's knot
   joints showed some slippage at moderately high loads!)!)

Dragging across a surface might be a condition that is deemed
*practical* in terms of modeling some realities of use, where
there is not only variable forces upon the knots but also the
rubbing of surfaces.

(I have been pretty surprised that fairly tightly set grapevine
and other knots have loosened in my pocket --not real quickly,
but, still, after not so long.  (Not testing, I didn't note the date
of the tying vs. finding the knot(s) loose.)


--dl*
====
Title: Re: Ashley knot security tester
Post by: Tangled on August 13, 2015, 03:26:40 AM
I tied a loop of two parallel paracord strands joined at intervals with an Alpine Butterfly Bend, Sheet Bend, Double Sheet Bend, Sheet Bend and a Half Hitch, Carrick Bend (uncapsized), Figure 8  Follow Through, and an Overhand Follow Through.  I closed it with glued Grapevines.  I marked each chord where it entered the knots and hung it in my SUV.  Nice, busy ride on most streets guaranteed to rattle loose anything not under tension.
Title: Re: Ashley knot security tester
Post by: Mobius on August 13, 2015, 10:08:49 AM
What I call the "Jiggle Test" might be useful. Shown here: https://drive.google.com/open?id=1ayKyc8E_3x-jGli252wuiAmlmXe3bJu2g8lJzl_eSeI is just my personal way of looking at 'slack' knot security. Shaking a knot to see whether it holds form is not new, however I decided to at least somewhat formalise what knots are worthy of my further investigation. i.e. a knot that falls apart after a couple of shakes in my trial does not excite me very much ;) My link is just part of my knot diary, take from it what you will.

Of course, I am using 11mm kernmantle as my benchmark and I fully appreciate that other materials will produce different results. Take that as you will, however you may wish to do your own informal trials for a particular rope and knot. Soft rope is not a good choice IMO.

Cheers,

mobius.
Title: Re: Ashley knot security tester
Post by: Urfin on September 15, 2015, 01:59:37 PM
I have various small cords attached to my keys cord
and I find that most knots work loose in my pocket,
with a notable exception being the zeppelin-knotted
ends of a small binding cord (a hollow braid of nylon),
where the tails are minimally short and *blossomed*
so that they cannot be pushed and also serve to some
degree qua stoppers --that end-2-end knot has been
tied for years, even decade(s)?! !!  (But another such
knot tied in ends of 3/16" solid braid nylon cord on this
collection of stuff in my pocket was pretty quickly too
loose!

I've done some similar unscientific experimentation by carrying some knotted cords in my pocket too and I used to tie the ends with a Zeppelin bend. It was regularly getting undone, so I got tired of it and switched to Vice Versa bend and had no problem since. It is a 3mm kernmantle cord, rather firm and usually it holds knots rather well. This experience made me always wary of the Zeppelin and it was always surprising to see people being so fond of it and describing it as secure. It never occurred to me that it'll work better in a different material, thank you for that idea, it clears some confusion.
Title: Re: Ashley knot security tester
Post by: Dan_Lehman on September 15, 2015, 07:04:52 PM
If you "switch" to an even more complex/convoluted bend
( for example, if you add two half hitches to the Tail Ends of ANY bend you wish...)
 your knot will pass the test of the [...]
Noope, if you "secure" further by insecure means,
you will often have still an insecure structure --i.p.,
those half-hitches will loosen and then too the rest
of the structure, in many cases.  (Sometimes, there
might be some benefit to a conglomerate; YMMV.)

I suspect that the vice versa worked -as much as it did
(but for how long?!)-- because it could be tightened to jam,
unlike the z. which has non-jamming as a key feature!
In my pocket knotting, though, I found even the strangle
components of the grapevine bend to loosen, although
pretty *firmly* set --no, I didn't put huge setting forces
on them, as that can set-jam many knots, and I think that
a "secure" one should work w/o such great setting forces.


--dl*
====
Title: Re: Ashley knot security tester
Post by: Urfin on September 16, 2015, 04:38:18 PM
If THIS experience made you "ALWAYS" wary about the "security" of the Zeppelin bend :) , perhaps you are who is still a little confused about what is a "secure" knot...

Well, I'm here to learn. Do you mean that security of the knot is defined only as security when loaded? I probably misused the term, what I meant is the general ability to withstand random tugs, rubs, and pushes. Robustness?
Title: Re: Ashley knot security tester
Post by: Mobius on September 18, 2015, 06:33:13 AM
If THIS experience made you "ALWAYS" wary about the "security" of the Zeppelin bend :) , perhaps you are who is still a little confused about what is a "secure" knot...

Well, I'm here to learn. Do you mean that security of the knot is defined only as security when loaded? I probably misused the term, what I meant is the general ability to withstand random tugs, rubs, and pushes. Robustness?

A knot's slack security (robustness) is very important. It is a part of what defines the overall security of the knot. There are plenty of knots (bends, loops, adjustable-loops) that perform well in the areas of being easy-to-tie, non-jamming and do not fall apart the moment you jiggle the rope with no load. BTW, just because a loop is 'adjustable' does not mean that you have to live with it falling apart easily :)

Tying a knot and then at least 'jiggling' it to see whether it holds together is a must for me and a prerequisite quality as far as I am concerned.
 
Cheers,

mobius.

Title: Re: Ashley knot security tester
Post by: Mobius on September 18, 2015, 10:22:36 AM
   "Jiggle" a not-loaded Gleipnir, and see is it "holds together" or "falls apart" ....
    Then, do the same on a not-loaded bowline. After you will dismiss those two great knots, you will probably be forced to discover by yourself that there are great knots which are "holding together" only with the help of the friction generated by some tensioned, due to the load itself, segments of their nubs, not by any pre-tensioned segments, due to the pull of the ends of their nubs by the knot tyer ( during a post-dressing, pre-tensioning phase, as it happens in the case of the "tight hitches" ).
    Of course, you can re-define "security" as you wish - and live happily all your life believing, deep in your heart, in the "practicality" of your definition. People do this all the time, and in things m u c h more important than knots : they believe that airplanes are not secure means of transportation, vaccines are not secure means of preventing contagious diseases, the 13th floors are dangerous, e.t.c - and many of them also believe that we should better consult an astrologist before we dare to attempt anything of those "dangerous" things. So, I am sure that there are some people who believe that "secure" knots are only the over-tangled knots, or the jammed knots - or, better, the glued knots, and they are happy to use only such knots. One thing is sure : they will NOT die because any of their knots will be released due to "giggling" ! :)

   P.S. I deliberately have not referred to the Blackwall hitch, because I do not know if it can even be considered as a "knot", if/when/while it is not loaded.

More condescending rubbish spills from the xarax's mouth. I am accused of redefining knot "security" by talking about 'slack security' and actually saying I think it is important. What a heretic I am  ::)  I find xarax's astrological', 'vaccine', 'glued knots' argument is one of the most pitiful I have ever seen from him. Unfortunately, xarax gets away with saying this type of insulting nonsense time after time (after year), it is the rest of us who must be careful what we say.

You are welcome to think about slack security for yourself. Ask yourself this, if we are so happy with the performance of a standard Bowline (well known for it's slack security issues) why are there thousands of posts about trying to improve it? The Bowline or even Double Bowline do not pass the "jiggle" test, some (if not most) of the bowlines now proposed for serious consideration (peer review) will exhibit a number of fine qualities, slack security being one of them is almost a given.

Cheers,

mobius

Title: Re: Ashley knot security tester
Post by: Dan_Lehman on September 18, 2015, 06:45:52 PM
Practical knots are practical things, so the criteria by which we judge them should be practical, and reasonable, and not far-fetched or even imaginary. The Zeppelin bend is a most secure bend - and we should not care too much if the keys inside Dan Lehman s pocket become separated after 35 years - I do not know if the locks, the doors and the house which they open are still there by this time.   
Apparently you missed what I wrote and picked only
the seemingly lauditory report of a particular tied knot
--with minimal tails frayed open into stopper-like blooms.
Let me help you out, with repetition --a key to learning:

Quote
I have various small cords attached to my keys cord
and I find that most knots work loose in my pocket,
with a notable exception being the zeppelin-knotted
ends of a small binding cord (a hollow braid of nylon),
where the tails are minimally short and *blossomed*
so that they cannot be pushed and also serve to some
degree qua stoppers --that end-2-end knot has been
tied for years, even decade(s)?! !!  (But another such
knot tied in ends of 3/16" solid braid nylon cord on this
collection of stuff in my pocket was pretty quickly too
loose![
/b]  (Moderately tightened grapevine bends have
loosened, also.)

--dl*
====
Title: Re: Ashley knot security tester
Post by: xarax on September 19, 2015, 02:13:51 AM
   THAT is how one can make you reply to a post, even if this reply is not on-topic : Write something about what y o u had said, not about the topic ! :)
   Let me help you out, by noticing that you, or your "report" :), were NOT the main points of my previous posts.
   The main points were that :
   1. < The Gleipnir and > " the adjustable loops I had tied are meant to remain in one piece ONLY if they are loaded, otherwise they are self-un-adjusted and self-released, of course... :))"
   2.   "The Zeppelin bend is a most secure bend  "- and one reason for this is that when we pull its ends it shrinks, but it does not "swallow" its tails.
   3.   "There are great knots which are "holding together" only with the help of the friction generated by some tensioned, due to the load itself, segments of their nubs, not by any pre-tensioned segments, due to the pull of the ends of their nubs by the knot tyer ( during a post-dressing, pre-tensioning phase, as it happens in the case of the "tight hitches" )."
   4.   Regarding the claim about the supposed/imagined "insecurity" of the knots which "do not fall apart the moment you jiggle the rope with no load"(sic), I had mentioned the Gleipnir and the bowline - and I had also noticed that :
   5.  " I deliberately have not referred to the Blackwall hitch, because I do not know if it can even be considered as a "knot", if/when/while it is not loaded."

    THOSE were my main points ! I have not seen a n y comment on them, but I am accustomed to that... Now, I only want to suggest you need not care so much about my joke ( although I had noticed that many people in this Forum are not "perceiving" what I think is a joke, as a joke... ) :
    " and we should not care too much if the keys inside Dan Lehman s pocket become separated after 35 years - I do not know if the locks, the doors and the house which they open will still be there by this time."   

   One thing is certain : I will never find out if they will be there by this time, or not - I do not plan to live so much. :)
Title: Re: Ashley knot security tester
Post by: Mobius on September 19, 2015, 03:57:39 AM
   THAT is how one can make you reply to a post, even if this reply is not on-topic : Write something about what y o u had said, not about the topic ! :)
   Let me help you out, by noticing that you, or your "report" :), were NOT the main points of my previous posts.
   The main points were that :
   1. < The Gleipnir and > " the adjustable loops I had tied are meant to remain in one piece ONLY if they are loaded, otherwise they are self-un-adjusted and self-released, of course... :))"
   2.   "The Zeppelin bend is a most secure bend  "- and one reason for this is that when we pull its ends it shrinks, but it does not "swallow" its tails.
   3.   "There are great knots which are "holding together" only with the help of the friction generated by some tensioned, due to the load itself, segments of their nubs, not by any pre-tensioned segments, due to the pull of the ends of their nubs by the knot tyer ( during a post-dressing, pre-tensioning phase, as it happens in the case of the "tight hitches" )."
   4.   Regarding the claim about the supposed/imagined "insecurity" of the knots which "do not fall apart the moment you jiggle the rope with no load"(sic), I had mentioned the Gleipnir and the bowline - and I had also noticed that :
   5.  " I deliberately have not referred to the Blackwall hitch, because I do not know if it can even be considered as a "knot", if/when/while it is not loaded."

    THOSE were my main points ! I have not seen a n y comment on them, but I am accustomed to that... Now, I only want to suggest you need not care so much about my joke ( although I had noticed that many people in this Forum are not "perceiving" what I think is a joke, as a joke... ) :
    " and we should not care too much if the keys inside Dan Lehman s pocket become separated after 35 years - I do not know if the locks, the doors and the house which they open will still be there by this time."   

   One thing is certain : I will never find out if they will be there by this time, or not - I do not plan to live so much. :)

Who would of thought that anyone would have to argue the case that one of the basic knot expectations is that it doesn't fall apart easily?

The issue of the bowline and slack security is covered in my previous post. Presenting a new bowline, or bowlinesque loop on this forum that could not survive my simple 'jiggle' test and have that knot well received would be highly unlikely. As for the 'jiggle' test, it applies to bends and loops, as was clearly stated originally. That xarax chooses to try and denigrate the 'jiggle' idea because it does not apply to a Gleipner or Blackwall HITCH is more about stirring than about logic.

As for adjustable loops: If it is to be designated a loop then I expect it to hold together without load. A common expectation one would think. Knot tyers here search for excellence, not mediocre, fall apart knots. This is a very simple concept and one that many here would agree with. Adjustable loops can accomplish this, the 'HFP Slippery 8' is possibly the most well known of them. This knot and many of the adjustable loops proposed by Alan Lee as well do not fall apart with a 'jiggle' and work well.

Now enter the 'theoretical' world of a xarax adjustable loop: I did not find a single one that did not fall apart! To put it bluntly, they are useless as loops. If xarax wants to resume them them as hitches then some of them may have some interest. Unfortunately, xarax's penchant for fall apart loops extends past those he calls adjustable. The much touted (by xarax) Pretzel 'Eskimo' Loop 'jiggles' to a straight line rope after a few seconds. Not only that, if you do go to the trouble of loading it, it collapses very quickly! I have shown this previously when I trialled the HFP and Pretzel loop in another post.

Slack security is important. If you make what you think is a new loop then 'jiggling' the rope of your newly snugged loop to see it stays together is a pretty good first step in seeing whether that knot deserves more of your attention, or not.

Edit: I am not a big fan of adjustable loops generally, but the one I used below on my test rig has proved itself valuable. When setting up a simple pulley system with my rig I wanted to have the dimensions between load and anchor as efficient as I could. As a 'temporary' measure I used the depicted adjustable loop. It might be new, however whatever the case, you can be sure it does not fall apart when left unloaded. It passed my 'jiggle' test easily. The knot is so good that it has become a permanent fixture on my test rig and when I use the pulley it gets loaded and unloaded between 0kg and 300kg regularly. It holds like a charm and the 'U' shape tail becomes almost a 'L' under heavy load.

Cheers,

mobius.

Title: Re: Ashley knot security tester
Post by: Mobius on September 20, 2015, 08:35:54 AM
   As I had expected, and perhaps following the plan, even "before the rooster crows", it was my post which was deleted by the Moderators, and not mobius s.
   Justice ( the Lady with the double-edge sword..) ! Fairness ! "I" am the one who "hides" behind smileys :  mobius does not hide behind any-thing... :) :) :)

xarax, is right about one thing: I do not hide behind anything. I stand by my words.

I have waded through xarax's last vitriol (now deleted) and found nothing I have not seen before: More insults, condescension an accusation of lying and a complete lack of a sensible argument. xarax revels in belittling others and their knots, however taking criticism about his knots is clearly something he is incapable of handling in anything close to a reasonable manner.

I re-trialled xarax's Pretzel Loop in climbing rope. The image shown below is taken under load (about 300kg). The knot started collapsing around 100kg and was continuing to collapse. That a) the knot cannot even survive a simple 'jiggle' test and b) collapses under load is more than enough for me to dismiss this knot.

Cheers,

mobius

Edit: Forgot the image. Poorly focused I am sorry and the reason it doesn't look like a Pretzel loop is nothing more than an indication of how badly it collapsed.
Title: Re: Ashley knot security tester
Post by: Ruby on September 20, 2015, 11:13:45 AM
Quote
As a 'temporary' measure I used the depicted adjustable loop. It might be new ...

sorry but what's this new knot, any details?
Title: Re: Ashley knot security tester
Post by: Mobius on September 21, 2015, 07:19:37 AM
Quote
As a 'temporary' measure I used the depicted adjustable loop. It might be new ...

sorry but what's this new knot, any details?

It may well not be new, so I never made much mention of it before . The idea of it is so simple I figured someone must have talked about it before even though I went looking for it a couple of months ago. Anyway, it works on the same principle as the HFP Slippery 8 knot and may be no better (or worse). The reason I liked it enough to tie it for a practical application was that you just tie a strangle/transom knot and tuck the end in a 'U' shape, not much thinking involved for me  :) . A very simple loop in my opinion, as long as you have a good way of tying a Strangle/Transom to start with.

Note that the end just passes through the transom nub looking (and staying) straight. The knot relies on the strangle living up to it's reputation, which it seems to do.

Cheers,

mobius.

edit: changed I to It, which makes far better sense

Title: Re: Ashley knot security tester
Post by: Ruby on September 21, 2015, 09:26:56 AM
 a strangle/transom knot, so it's a double overhand knot? really easy , thank you
Title: Re: Ashley knot security tester
Post by: Mobius on September 21, 2015, 11:07:25 AM
Yes, a Double Overhand knot. I have not really tested it: I tied it, it held, it has stayed tied on my rig doing what was supposed to be a temporary job :)

Cheers,

mobius
Title: Re: Ashley knot security tester
Post by: Sweeney on September 22, 2015, 09:17:20 AM
The Bowstring Knot is even simpler and holds extremely well as long as the load is in a straight line. http://www.survivalworld.com/knots/bowstring-knot.html#.VgEOaflVikp (http://www.survivalworld.com/knots/bowstring-knot.html#.VgEOaflVikp)
Title: Re: Ashley knot security tester
Post by: Ruby on September 22, 2015, 11:33:26 AM
ok saw this honda in ashley's book ABoK #151  #227 #1024 #1127

an overhand plus a stopper which is still an overhand。that's still double overhand?
Title: Re: Ashley knot security tester
Post by: Mobius on September 22, 2015, 12:15:28 PM
ok saw this honda in ashley's book ABoK #151  #227 #1024 #1127

an overhand plus a stopper which is still an overhand。that's still double overhand?

No, I don't think so. Just because it has two overhands in it does not make it a 'double overhand', as described by Ashley. However, the Double Overhand, Constrictor, Strangle and Transom are very similar knots (arguably the same thing, particularly the last three as discussed here: http://igkt.net/sm/index.php?topic=5258.msg34460#msg34460 )

Cheers,

mobius
Title: Re: Ashley knot security tester
Post by: Sweeney on September 23, 2015, 05:43:05 PM
ok saw this honda in ashley's book ABoK #151  #227 #1024 #1127

an overhand plus a stopper which is still an overhand。that's still double overhand?

The Honda is a Bowstring knot with an added stopper - an adaptation for use when making a lariat and only used otherwise if there is a danger of the tail coming adrift.
Title: Re: Ashley knot security tester
Post by: Dan_Lehman on September 24, 2015, 05:03:15 PM
Yes, a Double Overhand knot.  I have not really tested it:
I tied it, it held, it has stayed tied on my rig doing what was supposed to be a temporary job :)
Austrian knot wizard Heinz Prohaska long ago advocated
this but with the (topological) dbl. overhand formed as
the anchor bend which better nips the tail.  He was
hoping to find a rockclimber's tie-in knot that could
endure incomplete tying, as happened to world-class
climber Lynn Hill (starting to tie in by reeving the rope
through her harness, then being distracted by another's
question/talk, and climbing w/o realizing she'd no knot;
she tragically realized this when leaning back to be
lowered, and fell (and survived)!).


--dl*
====
Title: Re: Ashley knot security tester
Post by: knotsaver on September 25, 2015, 11:34:31 AM

It may well not be new, so I never made much mention of it before .

It looks like the mirror version of this one shown here:
http://igkt.net/sm/index.php?topic=3315.msg19887#msg19887
Title: Re: Ashley knot security tester
Post by: Mobius on September 25, 2015, 03:16:25 PM

It may well not be new, so I never made much mention of it before .

It looks like the mirror version of this one shown here:
http://igkt.net/sm/index.php?topic=3315.msg19887#msg19887

Thanks for looking.

It's not B and I have spent some time looking at A and rearranging the loops. I don't think my rig version is either knot. However, I did find a flipped version of A that seems to work quite well (better snugging than the A version, which doesn't sit well for me).  I will take a picture tomorrow hopefully.

Cheers,

mobius
Title: Re: Ashley knot security tester
Post by: knotsaver on September 25, 2015, 04:20:29 PM

It may well not be new, so I never made much mention of it before .

It looks like the mirror version of this one shown here:
http://igkt.net/sm/index.php?topic=3315.msg19887#msg19887

It's not B and I have spent some time looking at A and rearranging the loops. I don't think my rig version is either knot.

(obviously not B)
Please look at the attached picture, if we start from the loose-back version of A and move "1" beyond "2" (in the picture) we obtain a mirror version of the knot shown in replay #17 and #20.
I don't know if they should be considered the same knot...
bye,
s.
Title: Re: Ashley knot security tester
Post by: Mobius on September 26, 2015, 03:43:01 AM

Please look at the attached picture, if we start from the loose-back version of A and move "1" beyond "2" (in the picture) we obtain a mirror version of the knot shown in replay #17 and #20.
I don't know if they should be considered the same knot...
bye,
s.

Very good, simple when you showed it to me :) I just couldn't get it to rearrange last night.

I did rearrange A into my first image below, which I now realise is also my rig knot with the loops swapped. It looks ok as an adjustable loop too (not tested). The other image popped out when I was fiddling late last night as well. It is a similar nub to the first, with some role reversal of the SPart.

I had a very quick look at finding the second loop (which seems ok, not tested). I found an Alan Lee one that was close, but I would be very surprised if there is not an image of the second loop somewhere here on this site. It looks familiar.

How much of a topological geometrical change makes a new knot? I think there is enough here to say xarax's 'A' loop and my rig knot are different.

Cheers,

mobius

edit: I added the Alan Lee knot I thought was at least a semblance to my second image, Alan's is a good knot I believe, though does the looping of the tail end still qualify it as 'adjustable'?
Title: Re: Ashley knot security tester
Post by: knotsaver on September 26, 2015, 06:43:27 AM
As Dan Lehman noted here
http://igkt.net/sm/index.php?topic=3315.msg19893#msg19893
Interesting that you took the dbl.overhand knot in the form of
a *reversed* anchor bend ... !?  Heinz Prohaska some time ago
presented a similar knot, using the anchor bend right-side-around, ...

In the 2 pictures you showed the double overhand is an anchor bend (reversed or not)


How much of a topological change makes a new knot? I think there is enough here to say xarax's 'A' loop and my rig knot are different.

How much of a geometrical change... in this case the topology is the same, the geometry changes...
bye,
s.
Title: Re: Ashley knot security tester
Post by: Mobius on September 26, 2015, 07:05:46 AM
How much of a geometrical change... in this case the topology is the same, the geometry changes...
bye,
s.

Changed it, thank you

Cheers,

mobius
Title: Re: Ashley knot security tester
Post by: alanleeknots on September 26, 2015, 09:11:09 PM
Hi all,
        Mobius, when I present the Triple overhand knot-based adjustable loop
        at Reply #92   http://igkt.net/sm/index.php?topic=5383.90.
        I have tie another version of Double overhand knot-based adjustable loop, I didn't post it because it will jam on heavy load.
        I have the load test here to show the difference between your version and my version.

        Picture #3 and #4, I loaded it till your SP-Tail Reversed loop just start to jam and I release the load to check on both loop,
        your  SP-Tail Reversed loop just kind of hard but manage to untie, but my loop is very easy to untie.

        謝謝  alan lee
Title: Re: Ashley knot security tester
Post by: Mobius on September 27, 2015, 05:01:30 AM
Hi all,
        Mobius, when I present the Triple overhand knot-based adjustable loop
        at Reply #92   http://igkt.net/sm/index.php?topic=5383.90.
        I have tie another version of Double overhand knot-based adjustable loop, I didn't post it because it will jam on heavy load.
        I have the load test here to show the difference between your version and my version.

        Picture #3 and #4, I loaded it till your SP-Tail Reversed loop just start to jam and I release the load to check on both loop,
        your  SP-Tail Reversed loop just kind of hard but manage to untie, but my loop is very easy to untie.

        謝謝  alan lee

Hi Alan,

Thanks for the feedback. I think this thread is in danger of turning into another 'adjustable loops' one, so I will make a response back in this thread http://igkt.net/sm/index.php?topic=5383.msg35985#msg35985

Cheers,

mobius