International Guild of Knot Tyers Forum

General => Chit Chat => Topic started by: Mobius on June 07, 2015, 07:02:47 AM

Title: Adjustable Loops
Post by: Mobius on June 07, 2015, 07:02:47 AM
EDIT: This thread underwent a number of name changes. It is much more about adjustable loops than anything else in it's present form

To immediately dispel the notion that some might think that I am primarily interested in a bowline's strength, I am not. I actually think security aspects like: non-slippage, verification, post-eye-tiable (PET), ease of tying, and a knot's non-jamming ability, far out weigh pure strength considerations.

This idea is just something interesting (and hopefully fun :) ) to do that I thought I might offer the forum. One notion to explore would be that a knot with a 3 diameter turNip is better strength wise than a bowline that has 2 diameters in the turNip.

Note that this exercise is about theory meeting practice. We all read things at this site that sound great in theory, or look good when you see an image, however what about the reality of it? Sometimes a 'theoretical" knot just does not live up to expectations, and vice-versa, a very good knot gets a "not acceptable" rating for a spurious "theoretical" reason. I, like most I expect, think about things theoretically and go from there. Unlike most, I have some trialling resources at hand, so theory can also meet practice.

My ego demands of me I try the two bowlines I have shown you recently:  The B&B Bowline and the Mobius "Eskimo" Bowline. Other bowlines I personally like and would like to trial are the:

Ampersand Bowline (xarax)
EBDB Bowline (Dan Lehman)
EBSB Bowline (Mark Gommers)

These three came to mind immediately, however I would really like to add some preferences from Scott, Alan, roo, alpineer, Tex, enhaut... you get the idea... anyone or all :)

So this doesn't get too big a project for me, I consider about 8 x 2 diameter and 8 x 3 diameter knots will be enough. The 2's can battle it out and so can the 3's. Then I will battle the best of the 2's with best of the 3's. I will also actually do some strength trials (in terms of kg loadings) of the two finalists, just so we can see how much strength difference we are actually talking about (if any).

This is not supposed to be a definitive test, just an interesting trial. We can discuss what knots make the trial and what doesn't. I will have a bit of time in a week or two to start.

Cheers,

mobius

Edit: changed the name from "knot wars" to 'Load testing of various Bowline structures'

Title: Re: Bowline "knot wars"
Post by: alanleeknots on June 07, 2015, 08:54:13 AM
Hi All,
         Mobuis I like your idea, Once a while I do the tug of war tests. what I found a lots of time Standard bowline is the winner.
         3 diameter turNip  have to be perfect condition to wine the standard bowline. how smooth the curve, which part of rope was
          underneath the region of highest stress point of the nipping loop, how loose or tight you dress the knot,  this is just some of
         them, I am sure there are more other factor can effect the out come that I don't know.
         Good luck anyway.

         謝謝  alan lee.
Title: Re: Bowline "knot wars"
Post by: Mobius on June 07, 2015, 09:25:46 AM
Hi All,
         Mobuis I like your idea, Once a while I do the tug of war tests. what I found a lots of time Standard bowline is the winner.
         3 diameter turNip  have to be perfect condition to wine the standard bowline. how smooth the curve, which part of rope was
          underneath the region of highest stress point of the nipping loop, how loose or tight you dress the knot,  this is just some of
         them, I am sure there are more other factor can effect the out come that I don't know.
         Good luck anyway.

         謝謝  alan lee.

(3D = 3 diameter, 2D = 2 diameter)

Interesting already, thank you Alan. I have never actually strength tested a standard Bowline. Maybe I should be adding some classic knots to the mix like the Right Hand Bowline (2D) and a version of the "Eskimo" Bowline (the most well known one, 2D).

What else should I try, the "Yosemite" Bowline perhaps? Scott's Locked Bowline?

I was thinking of dressing all knots I trial in their perceived best form. Most of the time that will be a snug nub I suppose, however I will dress a knot as best I can in the way it is supposed to be.

Cheers,

mobius.
Title: Re: Bowline "knot wars"
Post by: SS369 on June 07, 2015, 01:28:48 PM
Good day mobius.

Nice undertaking! And thanks ahead of time.
Of course test some of the standards against some of the newbies.
Please test the Simple locked standard bowline (Scott"s), though I don't think an increase of strength will be forthcoming.
Throw a Composite braided bowline in there too, if you'd like.
I have done a number of tug of war pulls before, pitting some of these using a one ton come-along, but with no measuring of tension facility.
The condition that needs to be standard, imo, is that the dressing of these should be snug - minimum space between parts.
I am of the opinion that 3D will lose the strength competition.

Looking forward to the results of your trials.

SS
Title: Re: Bowline "knot wars"
Post by: alpineer on June 07, 2015, 09:47:10 PM

The condition that needs to be standard, imo, is that the dressing of these should be snug - minimum space between parts.
 

Except the Bowline's Collar!!! I'm serious! It's not necessary. You really should appreciate this point SS. If you pull the the Collar tight up against the nub of some particular secured Bowlines you may have trouble loosening the knot after hard loading. Leaving a little room to flip the Collar back will not compromise security and will ensure easy untying of the knot.   
Title: Re: Bowline "knot wars"
Post by: alpineer on June 07, 2015, 09:57:28 PM
Hi mobius. I have three offerings for you to trial... two are 3D Bowlines and the other is what I call the Tresse Bowline. I'll send links or images later.
Title: Re: Bowline "knot wars"
Post by: Dan_Lehman on June 08, 2015, 06:03:54 AM

I am of the opinion that 3D will lose the strength competition.
Why?
(Let's have some explained theory out there!)

And I echo Alpineer's alarm at the "SS" setting of the bowline !    ::)

--dl*
====
Title: Re: Bowline "knot wars"
Post by: Mobius on June 08, 2015, 06:05:00 AM
Hi mobius. I have three offerings for you to trial... two are 3D Bowlines and the other is what I call the Tresse Bowline. I'll send links or images later.

Sure, images/links would be great. Showing me how to tie it is one thing, and not leaving me guessing on how someone wants it trialled is another :)

Some knots, you just look at them and know how to tie. Others you look at and really struggle to know how to tie (some knots interlace back and forward so much that they are 'Carrick' like and are really hard to follow. Help me out with images/best dressings if you can please :)

Cheers,

mobius
Title: Re: Bowline "knot wars"
Post by: Mobius on June 08, 2015, 06:12:50 AM

I am of the opinion that 3D will lose the strength competition.
Why?
(Let's have some explained theory out there!)

And I echo Alpineer's alarm at the "SS" setting of the bowline !    ::)

--dl*
====

Indeed, I have read a lot of theory saying 3D is better than 2D. That sounds reasonable, however is it? Some are suggesting otherwise, so I thought I would trial a few knots to see whether theory is supported, or not.

@Dan: I always liked your EBDB (simple, elegant, verifiable), is there something else you would like me to trial?

Cheers,

mobius
Title: Re: Bowline "knot wars"
Post by: Dan_Lehman on June 08, 2015, 06:27:27 AM
Note that this exercise is about theory meeting practice.
We all read things at this site that sound great in theory,
or look good when you see an image,
however what about the reality of it?
One needs to be careful, here : it could be that
what fails to live up to expectations isn't --in detail--
the theory but the knot-behavior.  E.g., consider
Bruce Smith's dismissal of theories of stronger/weaker
versions of the fig.8 eyeknot : he explains that upon
heavy loading, the apparently broader curve of the one
will in fact push its way to be as tight as the other
--which doesn't refute the broader-is-stronger theory,
but shows (if correct (and I challenge his knot tying!))
that the knot fails to hold true to the theory.

Alan Lee points to the same thing, in asserting that one
must see how well the various knots settle with force.

To this end, then, we should urge that you take photos of
the knots under stress, hoping that you can do that in
safety with a fairly accurate guesstimate of some 40%
tensile load which should be well shy of rupture, and
yet be a point beyond which little change in knot geometry
occurs --things just get a little tighter and ... BANG!

Quote
So this doesn't get too big a project for me, I consider about 8 x 2 diameter and 8 x 3 diameter knots will be enough. The 2's can battle it out and so can the 3's. Then I will battle the best of the 2's with best of the 3's. I will also actually do some strength trials (in terms of kg loadings) of the two finalists, just so we can see how much strength difference we are actually talking about (if any).
It might be usefully clever to set up the test
with eyeknotted specimens anticipating the break
at one end, and enabling the surviving knot,
with the long connective span, to be tied to
some other survivor (now we'll need a very strong
end-2-end knot :: blood knot, grapevine, twin fig.8 ?
Alternatively, one might simply tie off the broken end
with the same-as-survivor eyeknot,
and then get a test of "pre-loaded vs. new", perhaps
of some help!?


So, you say you have some testing gear :: what do you
have?  --what sort of device, what material(s)?!

When sent off a precious few (7) eyeknots to be tested
in Dyneema, I sewed into the line at pertinent points
some marker threads, for I figured that test values would
mean less (and the ranking loosely implied by them)
than learning where rupture occurred (insofar as my
marker threads could show that).


--dl*
====
Title: Re: Bowline "knot wars"
Post by: Dan_Lehman on June 08, 2015, 06:44:32 AM
Indeed, I have read a lot of theory saying 3D is better than 2D.
That sounds reasonable, however is it?
The general theory is that a more gradual curve of
the material is kinder to it, and spreads the friction
over a greater area, and so on; the particular/specific
part is that nipping 3dia in fact does this; but Alan points
out that particular geometry might not be so favorable
--consider if those 3 diameters are aligned w/axis of load,
so effectively the turn is 1dia.
THIS IS WHY WE NEED TO SEE THE ACTUAL GEOMETRY,
not a static image made prior to load, or a diagram of the
supposedly tied knot!!

Quote
Some are suggesting otherwise, so I thought ...
What I ASKED (of Scott) and all should think is Why ... not?
Let's explain this counter-theory!

Quote
@ Dan: I always liked your EBDB (simple, elegant, verifiable),
 is there something else you would like me to trial?
I'll want to see the draft list of candidates,
and then try to make any improvements to the set,
looking for things that might not be present in the
current selection.  (E.g., the Yosemite bwl. really
offers nothing that I can see to the common one,
re strength-enhancement (though I've read one author's
assertions that he tested it in A-vs-B testing vs. the fig.8
and it (always?) won; but he also asserted that the usual
break-testing and returned force values (which show the
contrary result --fig.8 well stronger--, are not proper
testing :: I cannot understand that, at all --the knots get
force, and if indeed one goes to a higher load in the test
device, than it should be the survivor in A-vs-B testing!
.:.  something's smelling funny with these assertions!)
AH,
but to the point : I want my alternative to the YoBowl
tested, as it takes the tail around the other way,
counter the S.Part's draw, and so will test whether
that draw and positioning of the tail matters!

--dl*
====
Title: Re: Bowline "knot wars"
Post by: Mobius on June 08, 2015, 07:34:08 AM

So, you say you have some testing gear :: what do you
have?  --what sort of device, what material(s)?!

--dl*
====

There were a lot of good points raised, however I will answer this one now:
Quote
Synthetic Braids

Donaghys range of multi purpose synthetic braids are strong, lightweight and abrasion resistant.  They are suited to a wide variety of general purpose applications.

    Smooth (16 plait) & textured (8 plait) options
    Hard wearing HT polyester fibre in supple plait construction
    Highly resistant to stretch, abrasion, UV degradation and discolouration
    Excellent knotting and untying properties


I chose this braid because I hoped it would mimic (somewhat) the qualities exhibited by a professional style 'static' rope. All I can offer is, after having just purchased some good 11mm Kernmantle (Arborist/Abseiling/Rescue) rope, that it does have things in common with larger diameter ropes of quality. One thing is that it is very stiff (stiffer than the Kernmantle I have); secondly, it appears to hold its circular x-section well under load; thirdly when I tie it and cinch the nub I do end up with something that looks like I had tied it in Kernmantle (except smaller).

A trial is a trial, and these will be home ones, so far from scientifically controlled. I have purchased a crane scale and can test up to 300kg with it. The braid I chose has a breakload of 200kg (according to the fact sheet). For what it is worth, I have learned a lot about knots through having trialled them. The braid I am using is not 'soft' and forgiving of a poor knot. Quite the opposite I believe, I have to be diligent in dressing and cinching even a good knot. Some knots 'look' good in theory and do not live up to it from what I have trialled. Ignore what findings I give (some have) or take them as sign of promise, or perhaps one of caution.

Cheers,

mobius
Title: Re: Bowline "knot wars"
Post by: zoranz on June 08, 2015, 12:26:40 PM
I am not invited to give suggestions (and really there is not any reason for it, I am only passive observer). But, I should like to include Double Bight Bowline (= Prohaska bwl = Janus bwl, one variant) in the "war".
Thx, regards
ZZ
Title: Re: Bowline "knot wars"
Post by: Mobius on June 08, 2015, 12:36:32 PM
I am not invited to give suggestions (and really there is not any reason for it, I am only passive observer). But, I should like to include Double Bight Bowline (= Prohaska bwl = Janus bwl, one variant) in the "war".
Thx, regards
ZZ

Everyone is invited to make suggestions :)
Title: Re: Bowline "knot wars"
Post by: agent_smith on June 08, 2015, 01:37:39 PM
Quote
One notion to explore would be that a knot with a 3 diameter turNip is better strength wise than a bowline that has 2 diameters in the turNip.

This holds interest to me but only if it has some scientific rigor in the test method and if it an prove certain hypothesis. If it does, then it would be of interest to include results in the 'Bowlines analysis' paper.

There have been many knot testers before you...and I would go so far as to say that in excess of 90% of cases - the results are near worthless (this comment might open me up to attack). The problem - in my view - is that the testers failed to establish robust test parameters - and then simply did knot A Vs knot B test and declared winners based on that short-sighted data.

I would support a test of the following parameters.

[ ] First test to establish baseline parameters - unkotted rope strength and then ABoK #1010 (Note: for unknotted rope test, you must fix each end with a 'tensionless hitch' containing at least 6 turns)
[ ] Identical knot specimens tied in both ends of the rope (so you have a survivor knot specimen to study and photograph)
[ ] Bearing point (BP) of eye to bearing point (BP) of eye length is always constant (eye of the knot to the opposite eye of the knot) - 500mm
[ ] Insert colored marker threads into the knots at strategic positions - photograph in pre-stressed state and then post failure state
[ ] Always use same rope type/model - don't change rope during testing
[ ] Always ensure the 'eye' of each knot is identical in size (same dimensions) - report size pre and post test
[ ] Always ensure that the same amount of tail is present in both knot specimens (eg 50mm tail) - report length pre and post test
[ ] Always ensure that both knots specimens at either end begin with identical dressing (ie cinched to same tension and form) - or as near to 'identical' as you can achieve
[ ] Take a photo of a knot specimen in its pre-loaded state - close up against a pure white background - and then indicate each of the dimensions - and these dimensions must always be identical for each test - eg eye size, tail length, eg for #1010, indicate tail length and eye dimensions.
[ ] I would suggest that you use a rope diameter of at least 8.0mm - but preferably larger diameter (although this will of course require much higher forces to cause failure). I am not in favour of using very thin cord as the rates of change in the dimensions of the nipping helix structure in thin cord is too small. I urge you to invest in thicker diameter cordage. Also, I urge you to to use kernmantel type cord - that is - cord used in climbing/abseiling/rescue applications. It will be more economical to purchase say 8.0mm cord in bulk on a spool (50m/100m).
[ ] Please report if the knot specimen jams (or is jam resistant) - if it jams, please report the threshold at which jamming commences (ie at what tension force does jamming occur?)

Sequence:
1. #1010 (500mm BP to BP) - single helix nipping structure (only 2 rope diameters inside captured inside single helix nipping structure)
2. #1010 (500mm BP to BP) - single helix nipping structure - with tail inserted back through nipping structure to create 3 rope diameters (see photo) - could be as per the photo below or perhaps Heinz Prohaska 'Double bight Bowline'
3. #1013 (500mm BP to BP) - double helix nipping structure
4. #1013 (500mm BP to BP) - double helix nipping structure - with Alan Lee's lock (tail inserted back through nipping structure to create 3 rope diameters)

In my view, this structured testing will help to identify what effect adding an extra rope diameter into the structure will have. Also, it will be interesting to compare a single helix nipping structure against a double helix nipping structure. This means that your testing will be a case of 'Single helix Bowline with 2 rope diameters Versus Double helix Bowline with 2 rope diameters and then move on to the Bowlines that have 3 rope diameters captured within the nipping helix structure (instead of simply Knot A versus Knot B type mentality).

Make sure you eat plenty of carrots before attempting to sew Dan Lehman's notorious little marker threads in to the knot specimens. Also, be sure to chant his name while doing the needle work

Note: Please take your photos against a pure white background - and ensure no shadows are cast. If you do that, I will then be able to work with the images to bring them up to a high quality for you. But, if you don't shoot against a pure white background - there will be nothing I can do... It will also be helpful if you use a rope with a uniform color - for example, I like to work with Blue as it is easy for me to manipulate the saturation and tone curve because obviously blue is one of the primary RGB colors.

After obtaining these data points, you could then try testing different nipping structures - such as those based on a 'crossing hitch' (ie munter hitch). Eg Crossing hitch nipping structure versus standard #1010 single helix nipping structure.

If you can capture all of this data, it will be of immense value :)

Mark G

Edited: with additional important test parameters (eg tail length identical on both knot specimens - as this will provide insight into how this length changes as load increases to failure... and the eye of each knot must be of the same dimensions)
Title: Re: Bowline "knot wars"
Post by: Mobius on June 08, 2015, 02:14:13 PM
Thanks Mark,

There are a lot of good points made and good suggestions.

To start with, I would have to find a different braid to use, my current one is stiff and white. Sewing markers into this 3mm braid would require a lot more than carrots ;) Also, I am actually quite happy with the characteristics of the braid I am using (stiff, smooth, holds it cross-section), I would want to find the same type of braid, except not in white.

The methodology you suggest is possible, though this project suddenly got a lot larger if I go that way. I will consider everything you indicated.

Cheers,

mobius
Title: Re: Bowline "knot wars"
Post by: alpineer on June 08, 2015, 02:34:40 PM
Hi mobius, here's one of my knot offerings (photo credits agent_smith)...let's call it Alpineer's Bowline for identification purposes.
(http://igkt.net/sm/index.php?action=dlattach;topic=1202.0;attach=4797;image)      (http://igkt.net/sm/index.php?action=dlattach;topic=1202.0;attach=4795;image)
Title: Re: Bowline "knot wars"
Post by: Dan_Lehman on June 08, 2015, 09:07:30 PM
Sewing markers into this 3mm braid would require a lot more than carrots ;)
Methinks the rumor of difficulty is greatly exaggerated!
One merely needs to get the marker beneath some of
the mantle yarns, perhaps making a 2-3-tuck marking;
this can't be onerous!  --NOT going through the center
and all.  If testing w/equals on each end, like marking
should give information from survivor re loser; otherwise,
photo of in-tension knots will help indicate what's what
in position.

Well, re-reading more closely, "3mm" does present difficulty.
On the white thread, though, it offers an easier method : SHARPIE!
(yeah, there's some aspect of claiming that the marking itself has
effected damage; I think one can avoid such charges by marking
safe areas, and if the rupture comes elsewhere, well then ... !)

(While tapered/conical, carrots will not be adequate qua needles.   ;D )

--dl*
====
Title: Re: Bowline "knot wars"
Post by: SS369 on June 08, 2015, 11:12:03 PM

I am of the opinion that 3D will lose the strength competition.
Why?
(Let's have some explained theory out there!)

And I echo Alpineer's alarm at the "SS" setting of the bowline !    ::)

--dl*
====


First: The 3D encirclement I suspect and have seen involves more movement under load. Hence the increase of friction and heat. As the load increases and the tighter parts get they are moving and abrading each other, inside and outer fibers. All that movement has to produce destructive forces. I don't believe that the available surface areas will allow dissipation fast enough, instead act like heat sinks and thus accumulate heat to the point of melting a strand and then another.
This may not be as much with natural fibers.

Second: I don't agree with Alpineers' alarm sounding. I have not advocated some "super snugging" as you have been worried about in the past. I do think a firm snugging of all the parts is important, to limit the nub parts movements under loads. A #1010 bowline with its collar snug is less inclined to capsize, imo. Snugging the collar has never been an undo challenge to untie, even after pulling a wooden bridge or crane lifted bundles with a bowline. Just flex the collar and voila! Easy peasy.

I believe that 3D can improve security with the potential for reduction of overall strength.

SS
Title: Re: Bowline "knot wars"
Post by: alpineer on June 08, 2015, 11:29:27 PM
 (http://igkt.net/sm/index.php?action=dlattach;topic=4687.0;attach=12734;image)           http://igkt.net/sm/index.php?topic=4687.0     


I'm cautious about this knot due certain security, jamming or unintended misuse with unintended consequences which I've not yet pondered, though it might make an interesting candidate for trialling. There's at least 4 distinct loading configurations. I'll defer to xarax to recommend one. 
Title: Re: Bowline "knot wars"
Post by: agent_smith on June 09, 2015, 12:34:46 AM
Hello mobius, I have added more key stroking content to my post at reply #14.

Would be good if you could also consider changing the title of this thread from 'Knot wars' to 'Load testing of various Bowline structures' (or something with a more scientific bent).

Mark G
Title: Re: Bowline "knot wars"
Post by: xarax on June 09, 2015, 01:01:39 AM
   1. security,
   2. jamming,
   3. unintended misuse 

1. You must be joking ! It is more secure than it should  :) ( meaning, this convoluted collar structure is an overkill ).

2. Perhaps. ( Although "jamming" is a very vague concept - I prefer the simple "difficult to untie", which is enough ! We want bowlines easy to untie - otherwise we do not need bowlines at all ! )
    When you see a "closed" knot tied on the Standing Part before, or even after the eye ( for example, an overhand knot, a fig.8 knot, etc - here the knot tied on the returning eyeleg is even worse !  :) ), you should be cautious... Under really heavy loading, even the returning eye leg will be pulled hard, and the knot tied on its continuation, the "collar structure", may "close" around itself too tightly.
    Now, there is a basic distinction we should make here : This "closed" knot can be tied before or after the tip of the "higher" collar, and this makes a great difference. If it is tied before the tip of this collar, it will absorb the full tension coming from the returning eyeleg ( that is, about 50% of the total load  ), and then it will become difficult to untie, that is for sure. However, if it is tied after the tip of the "higher" collar, as it happens here, the situation may be less dangerous. At the U-turn of the collar, the direct continuation of the returning eyeleg "uploads" a significant portion of the tension which runs through it ( because of the capstan effect - the collar is not a pulley, it can not revolve freely around the Standing End ! ), so the tension which "comes down" is much less that the tension which was "going up". With less tension, there is less danger of a too tight closing of the "collar structure".   
   Alan Lee has tied many bowline-like eyeknots with overhand knots or fig.8 knots tied on the returning eyeleg ( on the Standing Part after the eye ) - but, on most of them, they are tied after the "higher" first collar, so there is less danger of them being "closed" around themselves too tightly. Myself, I prefer to follow the rule of thumb, and avoid ANY such knot - so the eyeknots I now tie are PET-2, and they are less prone to jamming / untying difficulties.

3. I do not understand what you mean by this "unintended misuse"... This eyeknot is meant to be loaded mainly as a bowline ( that is, from the "yellow" end - the nipping loop is the yellow one ). If it will be loaded by the other, "blue" end, its "blue" "nipping structure" will be too complex, and its "yellow" "collar structure" will be too simple !   
   HOWEVER, there IS the issue of unintended dressing !  :) This eyknot can be dressed in a number of different ways, just as it happens with all the "retraced" knots which have parts traced with double lines - the fig.8 bend and fig.8 loop included. In other words, this knot is not self-dressing in one and the optimum way - and, judging from the fact that generations of climbers had not even suspected how many different dressings the fig.8 loop they use can have  :), I think that we should not expect that the average knot tyer would be able to distinguish, and to care, about the different dressings of this knot either. A badly / not-uniformly dressed knot can not be inspected easily, and can even become less strong than a properly dressed one - I think that the twistings and the other irregularities of the flow of the double line, especially around turns, will become the weak links of the nub.
   Read what, by coincidence, I had written just a few hours ago ;
   the double line is fine when it runs along straight segments, but poses problems when it makes O- and U-turns. Exactly as it happens in all such "retraced" knots ( meaning knots which can be tied in-the-end by retracing the path of the first line with a second line ) - the fig.8 bend and fig.8 loop, for example. In each turn, each of the two lines can follow the inner or the outer track, and so the knot can be dressed in many ways, and the most regular, streamlined dressing of them requires attention from the knot tyer. That is the reason I had abandoned the "shrunk", single-eye version of this loop : too many dressing forms mean that the knot is not self-dressing, and it can settle in a not-optimal form .
   
Title: Re: Bowline "knot wars"
Post by: alpineer on June 09, 2015, 01:06:18 AM
Second: I don't agree with Alpineers' alarm sounding. I have not advocated some "super snugging" as you have been worried about in the past. I do think a firm snugging of all the parts is important, to limit the nub parts movements under loads. A #1010 bowline with its collar snug is less inclined to capsize, imo. Snugging the collar has never been a undo challenge to untie, even after pulling a wooden bridge or crane lifted bundles with a bowline. Just flex the collar and voila! Easy peasy.
SS
I don't hear any alarm bells. :) But your judgement concerns me. 


Hi Alpineer.

I gave your construct a whirl using some Titan (BlueWater) 5.5mm Dyneema and as well I used 1/4 inch solid braid nylon.

I like the compactness of this bowline and it lives up to your claims, almost.

The knot was dressed as tightly as my hands could do, using all the parts individually till I had the affair as snug as possible.

What I find is that the during the ring loading, the parts migrate to the point of the collar almost being drawn into the the upper nip using hand strength and body weight, so I can only imagine what serious loading (both slow or sudden) would do.

The biggest drawback, to me, is that after loading it to 300 lbs and then bouncing using body weight, I had to use round nose pliers and a spike to untie it.

I believe that the double nipping coils act very much like double overhand or perhaps a constrictor. No doubt very secure!

Based on my quick unscientific tests I would say it would be a satisfactory tie in loop, except for the untie-ability factor. In my opinion.

Thank you for sharing this.

SS

In my "whirlings" I've loaded the Tresse Bowline in a range of cord sizes, in some cases by as much as ~750 lbs. and all were untied using only fingers. Loosen up that collar just a bit and you'll have both security and easy enough untying. As for ease of untying, nothing beats #1010. But it's nature is of the proverbial two-edged sword.

 


Title: Re: Bowline "knot wars"
Post by: SS369 on June 09, 2015, 02:18:45 AM
Second: I don't agree with Alpineers' alarm sounding. I have not advocated some "super snugging" as you have been worried about in the past. I do think a firm snugging of all the parts is important, to limit the nub parts movements under loads. A #1010 bowline with its collar snug is less inclined to capsize, imo. Snugging the collar has never been a undo challenge to untie, even after pulling a wooden bridge or crane lifted bundles with a bowline. Just flex the collar and voila! Easy peasy.
SS
I don't hear any alarm bells. :) But your judgement concerns me. 
Dan Lehman's  bells of alarm attributed to you.
Quote
   And I echo Alpineer's alarm at the "SS" setting of the bowline!

I don't see why my judgement is in question. I tie/use my knots my way, you yours.
There have been knots that I test and explore that I have snugged very tightly and some not so tightly. It sometimes depends on the material of what I am tying. That is what I deem necessary to evaluate some constructs. My comment to mobius was to snug his test specimens to a consistent point.

Quote
Hi Alpineer.

I gave your construct a whirl using some Titan (BlueWater) 5.5mm Dyneema and as well I used 1/4 inch solid braid nylon.

I like the compactness of this bowline and it lives up to your claims, almost.

The knot was dressed as tightly as my hands could do, using all the parts individually till I had the affair as snug as possible.

What I find is that the during the ring loading, the parts migrate to the point of the collar almost being drawn into the the upper nip using hand strength and body weight, so I can only imagine what serious loading (both slow or sudden) would do.

The biggest drawback, to me, is that after loading it to 300 lbs and then bouncing using body weight, I had to use round nose pliers and a spike to untie it.

I believe that the double nipping coils act very much like double overhand or perhaps a constrictor. No doubt very secure!

Based on my quick unscientific tests I would say it would be a satisfactory tie in loop, except for the untie-ability factor. In my opinion.

Thank you for sharing this.

SS


In my "whirlings" I've loaded the Tresse Bowline in a range of cord sizes, in some cases by as much as ~750 lbs. and all were untied using only fingers. Loosen up that collar just a bit and you'll have both security and easy enough untying. As for ease of untying, nothing beats #1010. But it's nature is of the proverbial two-edged sword.



As for the above quote: It was an honest appraisal using two different media that I have that show different aspects. The hard Titan cord shows off many knot's lack of security and the nylon shows the level of untie-ability.
A range of cord or rope sizes can influence attributes, but in my opinion, the material and construction design influences knot performance more.

SS
Title: Re: Bowline "knot wars"
Post by: alpineer on June 09, 2015, 04:30:42 AM
As for the above quote: It was an honest appraisal using two different media that I have that show different aspects.

The hard Titan cord shows off many knot's lack of security and the nylon shows the level of untie-ability.
A range of cord or rope sizes can influence attributes, but in my opinion, the material and construction design influences knot performance more.

SS

Your honesty and integrity were never in doubt by me, SS.

Of course, all aspects of material nature - including dimensions - determine a knot's performance. But do they explain per se the use of pliers and spike to untie the knot in your case? 

 
Title: Re: Bowline "knot wars"
Post by: Dan_Lehman on June 09, 2015, 05:41:45 AM
Hi mobius, here's one of my knot offerings (photo credits agent_smith)...let's call it Alpineer's Bowline for identification purposes.
(http://igkt.net/sm/index.php?action=dlattach;topic=1202.0;attach=4797;image)      (http://igkt.net/sm/index.php?action=dlattach;topic=1202.0;attach=4795;image)
!! This looks like an excellent variation :
it has a "proper collar" (per X);
it has an "end-binding" (per DL);
it is TiB (per X);
and it Yosemites the tail out the collar (per A_S!   ::) ).
.:. 3.5 for 3.5 !   ;D


Now, to describe the TIB alternative to the "YoBowl" that
I've mentioned, see the returning tail (into turNip of the right
image (which presents the better face to show!) connecting to the
other side of the collar-bight (which makes it like "right-handed" bwl),
and then coming back out of the nip into the final tuck as shown
--bypassing/leaving-off the "end-binding" loop around the right side,
around the crossing-point of the nipping loop.  One thus has a simple
overhand component formed by the tail instead of the fig.8
done by the YoBowl, and the tail will be in a position to be drawn
upon by the S.Part after tension flows over the tail-side eye leg.
(It is also EEL, qua overhand-based eyeknot pulling this
indicated tail, and still TIB.  Of the easy four such knots (varying
the way the collar is made/turned), I think that this described one is
best --most sure of holding orientation, and giving good curvature.)


--dl*
====
Title: Re: Bowline "knot wars"
Post by: Dan_Lehman on June 09, 2015, 05:59:21 AM
First: The 3D encirclement I suspect and have seen involves more movement under load.
Hence the increase of friction and heat.  As the load increases and the tighter parts get
they are moving and abrading each other, inside and outer fibers.
But this concern is more for real loading than for
what will likely generate knot strength --standard
slow-rate loading.  (Dave Merchant opined that such
heat aspects made the strengths of esp. the slow-pull
strong fig.9 not so much stronger than an overhand
eyeknot
when dynamically loaded.)

But I don't think that the difference here is like that.
For the common bowline, the tail can act like a roller
bearing upon the draw of the S.Part --moving by rotation
with the heavily loaded S.Part between that and the other
side of the collar bight (eye leg), and I think that that
might give the knot durability over cyclical loading;
but it wouldn't matter so much in slow, break-teast loading,
IMO.  I would like to see the tail set back away from its usual
spot vis-a-vis this rotation, such that the S.Part's draw would
rotate it to where it normally begins; I think that having the
hard-stressed S.Part bear into a relatively unstressed and
hence more compressible tail might be helpful (vs bearing
against a tensioned eye leg).  And so my urging for that
"other variation of Yosemite finish", though there the tail
part will be more held in that "back away" position, not
moving (but taking the fuller pressure of the S.Part vs.
putting that upon the eye leg).

Also, there has to be enough friction to reduce the force
on the eye leg of the turNip by 50% over the S.Part,
else --as has been seen in Dyneema and a double-turNip(!)--
the eye will collapse by feeding out through this turn
--having say a reduction to only 65% and so opposed on
the other eye leg by 35%.  But a sharper turn gives more
resistance-to-bending (additional to friction) ?!

As for the "SS setting", I recall distinctly the sever bend
you put into the S.Part in one image, and that would put
lots of pressure upon the turNip's crossing point, before
force flows around the loop; that worried me.  (Yes, it would
defeat capsizing!)

As for jamming, that will come with elastic ropes when the
diameter diminished so much and parts close around, and
then on tension release the outside-of-constrictions parts
become swollen large and cannot slip back into the knot!
YMMV.


--dl*
====
Title: Re: Bowline "knot wars"
Post by: alpineer on June 09, 2015, 06:34:09 AM
There's also an interesting #1010 version of the Alpineer Bowline where the working end crosses over the collar's root before plunging into the turNip, continuing around the turNip's crossing part and plunging back into the turNip in the same direction before exiting through the collar. In this case a Fig. 9 on the working end engages the turNip.
Title: Re: Bowline "knot wars"
Post by: Dan_Lehman on June 09, 2015, 07:30:47 AM
First: The 3D encirclement I suspect and have seen involves more movement under load.
Hence the increase of friction and heat.  As the load increases and the tighter parts get
they are moving and abrading each other, inside and outer fibers.
We might also look to other knots, such as the fig.8 eyeknot
in which we don't see 3 diameters and yet have --sometimes,
at least(!)-- great strength, and wonder then at how the 3dia
comes to be so needed!?  (I have some idea that the F8 gets
strength from the turning of eyeleg parts around the S.Part
as it enters the knot, taking away some of the importance
of the ultimate U-turn's sharpness; although, in the push
comes to shove competition the S.Part's 100% nipping
might overwhelm the twinned 50% of those legs!?

One might test some rather comical, 5-6diameter? knot
just to so greatly emphasize that aspect, to see if it makes
a difference.  Then, again, one might consider some of
the test results for the bowline and ask How much more
strength is left to get?!
--some figures e.g. go to 80%.
. . . mysteries . . .  ???


--dl*
====
Title: Re: Bowline "knot wars"
Post by: alanleeknots on June 09, 2015, 08:29:24 AM
Hi All,
        Mobuis  You will be a very busy man. Please include this loop here with your "knot wars", will make ss  happy.

        謝謝  alan lee.
Title: Re: Bowline "knot wars"
Post by: agent_smith on June 09, 2015, 08:42:20 AM
Hi Alan,

Have you got a photo of the above knot with it tied loosely?
I am getting ready to take some more photos of your ingenious knot creations - and I have limited time - so just want to make it easier if I can quickly find all the info here in one place (yes, I am being lazy).

If you cant find it Alan - I know Luca is one of the worlds best blood hounds as he can sniff out any obscure piece of information from miles away :)

Mark G
Title: Re: Load testing of various Bowline structures
Post by: Mobius on June 09, 2015, 08:43:40 AM
Hello mobius, I have added more key stroking content to my post at reply #14.

Would be good if you could also consider changing the title of this thread from 'Knot wars' to 'Load testing of various Bowline structures' (or something with a more scientific bent).

Mark G
I will change the thread to your suggested name, though I am not sure how 'scientific' I can actually do trials though. It might take more than a couple of weeks to try and get material and methodology as good as I can for a home trialling situation.

One thing that occurred to me was that I often hear rope fibres start to break prior to complete knot failure. If I stopped the test at that juncture I could potentially mark the entry points into the nub carefully, cut the nub apart carefully and see where the rupture actually started. Was it the inside of the curve, or the outside of the curve, and where on the curve rupture actually started. This idea sounds alright in theory, but doing so in practice might prove really difficult.

Cheers,

mobius

Title: Re: Load testing of various Bowline structures
Post by: agent_smith on June 09, 2015, 08:55:08 AM
Quote
If I stopped the test at that juncture I could potentially mark the entry points into the nub carefully, cut the nub apart carefully and see where the rupture actually started.

Hello mobius,

Might have to defer to the 'big guns' of the IGKT for a clear-cut answer to that question. It might actually be an engineering question - so perhaps Derek Smith could weigh in (although Derek 'the dunny man' has been absent from this forum for some time I think?).

My spider senses tell me that cutting open a compressed knot structure will immediately release tension and therefore alter what you are seeing. Also, stopping the test before knot failure might also alter the heat flow/friction contribution to knot rupture.

I have no clear-cut answer...sorry.

Mark G
Title: Re: Bowline "knot wars"
Post by: alanleeknots on June 09, 2015, 09:36:41 AM
Hi Alan,

Have you got a photo of the above knot with it tied loosely?
I am getting ready to take some more photos of your ingenious knot creations - and I have limited time - so just want to make it easier if I can quickly find all the info here in one place (yes, I am being lazy).

If you cant find it Alan - I know Luca is one of the worlds best blood hounds as he can sniff out any obscure piece of information from miles away :)

Mark G

Hi Mark,
            Here is all my knots in here.  Thanks you.

            謝謝 alan lee   
Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on June 09, 2015, 09:39:19 AM
more picture
Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on June 09, 2015, 09:47:32 AM
more knots

" Lee Eskimo 8 bowline (A)" can't support heavy load, and will jam, I think we should abundone this loop.
   Hi Mark  I have one more loop posted in Reply #55  please have a look.
   (Edit date june-9-2015)
Title: Re: Load testing of various Bowline structures
Post by: xarax on June 09, 2015, 02:22:30 PM
   There are many TIB variations of the Alpineer s bowline. Read :
   http://igkt.net/sm/index.php?topic=4697.0

   After the trials by Alan Lee, I came to believe that this bowline will become difficult to untie after heavy loading, and I had abandoned it. The "link" around the rim of the nipping loop "closes" around itself too tightly - and this may happen in all "Link bowlines" .
Title: Re: Load testing of various Bowline structures
Post by: alpineer on June 09, 2015, 04:36:50 PM


   After the trials by Alan Lee, I came to believe that this bowline will become difficult to untie after heavy loading,...

Heavy loading, in what material?  I don't climb on what appears - in his images - to be soft laid frictive trolley cord, a material that would challenge many a knot's untiability. My particular interest in this knot is as a secure harness tie-in. As is the case with any knot, extreme differences in the cordage material can change a knot's performance characteristics.
Title: Re: Load testing of various Bowline structures
Post by: xarax on June 09, 2015, 05:07:26 PM
   Heavy loading, in what material ? 

  What I use to all "heavy", I guess that it should be a significant percentage of the MBS of the knot, or even of the line - say, 25%, 33,3%, or 50%. We have to define what we mean by this term - and it would be great if we could establish some benchmark loading percentages, and test our ropes in all of them.
  My own experience comes from kernmantle ropes, like those used in climbing, canyoning and rescue. I prefer them because they are stiff ( so they do not like sharp turns, and this makes me, too, to tie knots with wide, smooth curves ), they are not very compressible ( so they can not be flattened too much, and fill the voids in between the segments within the knot, turning it into a compact, massive and rigid ball which can not be un-knotted easily ), and they can retain an almost circular cross section ( so the contact area between two adjacent segments is not very extended ). I think that, in such material, the properties of the "knot" itself ( the geometry ) will manifest themselves more clearly, and the properties of the particular rope ( the material ) will play a secondary only role. I also tie knots in marine ropes, but I do not judge them by how they behave there - marine ropes are usually braided, and softer ( and less slippery ) than kernmantle ropes.
   Alan Lee has tried this bowline on such a climbing rope :
   http://igkt.net/sm/index.php?topic=4851.0
   He is much more creative in tying eyeknots, and experienced in trying them, than me - so, when he is not satisfied, I, too, am not !
Title: Re: Load testing of various Bowline structures
Post by: roo on June 09, 2015, 06:29:22 PM
   He is much more creative in tying eyeknots, and experienced in trying them, than me - so, when he is not satisfied, I, too, am not !
And yet when he reports that a Zeppelin Loop can be untied after taking twice (!) the safe working load of the rope, you apparently don't believe him (or anyone else, for that matter):

      Just to make sure to have more accurate reading, again I carefully tested the Zepplin loop,
       for soft rope after loaded 1200 lbs. is manageable to untie

the soft rope is 3000 lbs. breaking strength  and 300 lbs. safe working load.
If you take 1/5 of the 3000 lb as the safe working load, it'd yield 600 lb.  So it seems all the loops you're testing recently are performing well.
Title: Re: Load testing of various Bowline structures
Post by: xarax on June 09, 2015, 07:17:25 PM
  a Zeppelin Loop can be untied after taking twice (!) the safe working load of the rope

  The satisfaction of tying a pathetic knot that can only be untied when it is loaded by the "Working load" ( that is, a small fraction of the MBS...), can be all yours ! Because, evidently, you have not anything else...
  What a knot tyer can invent ( other than a decent knot, of course...- it seems that this is not so easy for some people ), in order to defend a frog-knot... If a knot is not a prince-knot, I am not interested in it - and I do not believe that frogs can be turned into princes with such cheap tricks.
   However, this particular frog has many more ugly characteristics ! It "closes" around itself not only too tightly, but also prematurely, leaving half of the knot loose, and so redundant... And it is not PET. AND it is a disgrace for the genuine Zeppelin knot, the Zeppelin bend ( provided one has managed to understand how a Zeppelin-like knot "works", and why it is easy to untie...- if he does not, it is a hymn !  :) ).

   ( However, if you share the marlinspike Dan Lehman uses for the Lehman8, you CAN untie the so-called "Zeppelin loop", indeed - which is NOT a Zeppelin-like knot, but I guess you will never be sincere/brave enough to accept it...)

Zeppelin loop is the worst one among all ,
 besides the name "Zeppelin", it really has no much to offer.
Title: Re: Load testing of various Bowline structures
Post by: roo on June 09, 2015, 07:40:59 PM
  a Zeppelin Loop can be untied after taking twice (!) the safe working load of the rope

  The satisfaction of tying a pathetic knot that can only be untied when it is loaded by the "Working load" ( that is, a small fraction of the MBS...), can all yours ![

I guess you missed the "twice (!)".  That's grossly exceeding the working load limit.  Is Alan is on your hit list now?  What a quick turnaround.
Quote
Because, evidently, you have not anything else...
Trolling again. ::) 

 
Quote
the so-called "Zeppelin knot", indeed - which is NOT a Zeppelin-like knot, but I guess you will never be sincere/brave enough to accept it...)
I know this is supposed to be an insult, but your mistyping makes it funny.   ;)   But seriously, I'm not interested in accepting your bizarre terminology.
Title: Re: Load testing of various Bowline structures
Post by: xarax on June 09, 2015, 07:47:21 PM
I guess you missed the "twice (!)". 

  No, YOU had not managed to divide 7663 by 1400... :)  :)

   Trolling again. ::)

  Fishing clients again !
   Is your knot-selling business going OK ? Because if it does, you will be truly satisfied, and you will not need this lamentable myth of the so-called "Zeppelin loop" ...

   How people who tell others to put trolls in their "ignore list", and offer detailed instructions for that, and who try to persuade themselves for 6 (six !) years now that I am a troll, do read my posts, is a MYSTERY !  :) :) :)
Title: Re: Load testing of various Bowline structures
Post by: xarax on June 09, 2015, 07:59:52 PM
  Oh, I did miss that  !
 
  Is Alan is on your hit list now?  What a quick turnaround.

   Poor roo... You try to divide and conquer  :), - when you can not even divide 7663 by 1400...  :)

   I can safely conclude that the ratio of the British Empire, which divided and conquered, to you, is the same as the ratio of the genuine Zeppelin knot, the Zeppelin bend, to your fake, so-called "Zeppelin loop".  :) :)   
Title: Re: Bowline "knot wars"
Post by: SS369 on June 09, 2015, 08:20:11 PM
Quote

Your honesty and integrity were never in doubt by me, SS.

Of course, all aspects of material nature - including dimensions - determine a knot's performance. But do they explain per se the use of pliers and spike to untie the knot in your case?

Thank you Alpineer for not doubting my honesty and integrity. That is what I will always strive for in evaluating an offering. I may be wrong, but I will be honest.  ;D

The use of the round nose pliers was needed for both those samples I tied due to small diameter ratios to finger size and materials. I can only suspect that if the loads were great enough on the larger diameter ropes the results would be accordingly similar. I have not tried them. I'll certainly take your report/results as honest at the loads you've subjected the knot to. NP.

SS
Title: Re: Load testing of various Bowline structures
Post by: roo on June 09, 2015, 09:06:44 PM
- when you can not even divide 7663 by 1400...  :)
I can divide those numbers, but they're not part of the equation:
http://igkt.net/sm/index.php?topic=5383.msg36061#msg36061

Re-read slowly.  Look for "soft rope".
Title: Re: Load testing of various Bowline structures
Post by: alpineer on June 09, 2015, 09:28:16 PM
Quote

Your honesty and integrity were never in doubt by me, SS.

Of course, all aspects of material nature - including dimensions - determine a knot's performance. But do they explain per se the use of pliers and spike to untie the knot in your case?
Thank you Alpineer for not doubting my honesty and integrity. That is what I will always strive for in evaluating an offering. I may be wrong, but I will be honest.  ;D

The use of the round nose pliers was needed for both those samples I tied due to small diameter ratios to finger size and materials. I can only suspect that if the loads were great enough on the larger diameter ropes the results would be accordingly similar. I have not tried them. I'll certainly take your report/results as honest at the loads you've subjected the knot to. NP.

SS

Thanks SS.
You might consider giving your same experiment a whirl with the nipping structure in Blood Knot - rather than Barrel Knot - configuration. Not sure if this will make any difference for you. 
Title: Re: Load testing of various Bowline structures
Post by: xarax on June 09, 2015, 09:31:04 PM
   Look, using your glasses, the pictures of Alan Lee, at :
   http://igkt.net/sm/index.php?topic=4849.msg33147#msg33147
   I was talking about THIS post... Do you see any "soft" rope ? If yes, you "see" things... :) :) :)

   It would be more clever ( to put it politely, because I could well had used the antonyms of those two words...) for you, to start a campaign ( and, who knows, a possibly successful advertising ) of the Ashley s bend turned into a loop. It has exactly the same properties as your beloved frog-knot, and you will not be alone in this... ( I guess that your usual ally, Dan Lehman, will be more supportive of the Ashley s bend turned into a loop, than he is now for the Rosenthal loop... :) )

P.S. I do not know which of the two dressings of the Ashley s bend should be used, in order to tie a less prone to jamming eyeknot... I have not tested them in loads heavier than the "Working load" = 1/10 th of the MBS of the line !  :)
Title: Re: Load testing of various Bowline structures
Post by: roo on June 09, 2015, 09:40:04 PM
   Look, using your glasses, the pictures of Alan Lee, at :
   http://igkt.net/sm/index.php?topic=4849.msg33147#msg33147
   I was talking about THIS post...
I quoted later on in that same thread where Alan revised his tests to get more accurate numbers and not just a rough guess.
Title: Re: Load testing of various Bowline structures
Post by: xarax on June 09, 2015, 09:58:54 PM
Alan revised his tests to get more accurate numbers and not just a rough guess.

   You "see" things, indeed ! Would nt it better ( for all...) to have some sleep ?
   Alan Lee had not revised ANY numbers, and those in the post with the knots tied on the "soft" rope  :) :)  I had referred to were the only ones in this thread. In another post, he just told you the "Working load" of the ropes he used - which, for the not-imaginary soft rope, was the 1/10th of the MBS !
   You tried, desperately, to argue that, because the so-called "Zeppelin loop" could be untied ( we do not know with what difficulty...) after it was loaded with the 1/5th of the MBS, and because 1/5th is double the laughable 1/10th, your frog has been a disguised prince right from the start !
   All those years you are trying so hard to sell this frog-knot, you did nt know that, if you accept as "Working load" the 1/10th of the MBS, ANY interlocked overhand-knot-based bend turned into an eyeknot, and loaded so lightly, will be easy to untie ? You waited Alan Lee to told you that ?
   However, I believe that, simply, you had not thought of this trick back then... Now that your frog-knot has be revealed in all its smallness, you invented this tactic of the "Working-load-untiable" so-called "Zeppelin loop" eyeknot !  :)  :)  I think that the other Nobel-prize worth strategy, of Dan Lehman, with his "Dyneema-untiable" Lehman8 eyeknot, is "more clever".   
     
Title: Re: Load testing of various Bowline structures
Post by: roo on June 09, 2015, 10:24:32 PM
   You "see" things, indeed ! Would nt it better ( for all...) to have some sleep ?
   Alan Lee had not revised ANY numbers, and those in the post with the knots tied on the "soft" rope  :) :)  I had referred to were the only ones in this thread. In another post, he just told you the "Working load" of the ropes he used - which, for the not-imaginary soft rope, was the 1/10th of the MBS !
   You tried, desperately, to argue that, because the so-called "Zeppelin loop" could be untied ( we do not know with what difficulty...) after it was loaded with the 1/5th of the MBS, and because 1/5th is double the laughable 1/10th, your frog has been a disguised prince right from the start !
   
You really need to slow down and re-read post several times before responding.  I assumed a harsher working load limit of 1/5 of the 3000 lb breaking load (working load limit = 600 lb) and Alan was able to untie things after applying twice this 600 lb (600 lb X 2 = 1200 lb) or 1/5 (not 1/10!) value.  Regardless of whether your misreading and/or misrepresentation of posts is accidental* or intentional, I give up. 

*Xarax's next clearly dishonest post talking about 1/10 & even 1/20 breaking loads cleared that up.
Title: Re: Load testing of various Bowline structures
Post by: xarax on June 09, 2015, 10:59:30 PM
I give up.
   
   Good !  :)  Go to sleep, now... Because the supposed "rough guess"(sic) was not where you had imagined you saw it...And because I was always talking about Alan Lee s numbers on not-soft ropes, shown in the post I had referred to MANY times, and where you had also imagined you have "seen" soft ropes. I was NOT talking about the test on the soft rope. I had said it dozens of times, that I am interested in climbing/industrial/rescue kernmantle ropes, not in fishing lines, easily-flattened ropes, elastic / bungee cords, etc. (  Now I have mentioned it, it may be a good idea to start promoting your frog-knot as a bungee-cord prince-knot !  I am sure that, on such a material, it will make a nice ball ! )
   
   Your not-so-clever, to say it politely, trick with the introduction of the 1/10th ( or even better, the 1/15, or the 1/20th ) of the MBS, as the maximum load with which we should load our ropes, to see if they are easy to untie or not, is only "bon pour l orient", I am afraid.. I made you a favour, and suggested to you two ways out of your obvious impasse : First, adopt another overhand-knot-based bend turned into loop, the Ashley s bend : Start selling the Ashley s loop ! That way, you will have an ally, Dan Lehman, and you will not have me revealing the frog-ness of the so-called "Zeppelin loop" to your clients... Second, adopt the Dyneema-inspired strategy of Dan Lehman : Start talking about how safe all those too-tight eyeknots are, when tied on Dyneema - that trick may save the a... even of your frog-knot !
Title: Re: Load testing of various Bowline structures
Post by: xarax on June 09, 2015, 11:34:11 PM
  able to untie things after applying twice this 600 lb (600 lb X 2 = 1200 lb) or the 1/5th (not the 1/10th ! ) value. 

   A peasant was complaining to the local priest that his house was too small, the 1/5th of what he would had wished. The priest tells him to put the horse into the house. After a week, the peasant goes again to the priest, and starts complaining more. The priest tells him to put the cow into the house. After two days, the peasant goes again to the priest, and tells him that the situation has become unbearable, and that now he is forced to live in the half of the house, i.e., in a house which is the 1/10th of what he needs. The priest tells him to put the pig into the house. The very next day, the peasant is begging the priest to do something. Then, the priest tells him to put the horse, the cow and the pig out of the house again. In just one hour, the peasant returns to the priest, and tells him how happy he is he now lives in such a big house !
   That is the "bon pour l orient" trick attempted with the invention of the "Working-load-untiable" eyeknot ! We choose a low Working load, say, the 1/10th of the MBS. Then, if our eyeknot can be untied after it has been loaded with the 1/5th of the MBS, we feel happy !  :)
   
   KnotGod made so many good knots, but then he got tired, and when he made the knot-tyers, he cut some corners...   
Title: Re: Load testing of various Bowline structures
Post by: agent_smith on June 10, 2015, 01:36:35 AM
Hello mobius,

When are you planning to commence testing your Bowline structures?

I need to know because I would like to use your data (with permission) in the 'Analysis of Bowlines and other selected Eye knots' paper.

Please advise....

Thanks, Mark G
Title: Re: Load testing of various Bowline structures
Post by: Dan_Lehman on June 10, 2015, 04:35:28 AM
   Heavy loading, in what material ? 

  What I use to all "heavy", I guess that it should be a significant percentage of the MBS of the knot, or even of the line - say, 25%, 33,3%, or 50%. We have to define what we mean by this term - and it would be great if we could establish some benchmark loading percentages, and test our ropes in all of them.
There are two senses here : that of the proportion to the
tensile strength; and that in proportion to manual strength.

In the first instance, note that the tightness of the structure
can differ widely per strength of the material, even though,
from one perspective, different materials present the same
sort of feel/size --but snap your fingers and magically convert
multifilament polypropylene into HMPE and suddenly that
force that was X% of tensile is now only X/5% or so(!!),
but the tightness is the same.

And otherwise, although Paul Bunyan (a mythical giant)
might find the knot tied in 1" line subjected to normal,
expected loads while mooring the trawler to be easily
untied, a mortal (wo)man might not.  YMMV.

Quote
  My own experience comes from kernmantle ropes, like those used in climbing, canyoning and rescue. I prefer them because they are stiff ( so they do not like sharp turns, and this makes me, too, to tie knots with wide, smooth curves ), they are not very compressible ( so they can not be flattened too much, and fill the voids in between the segments within the knot, turning it into a compact, massive and rigid ball which can not be un-knotted easily ), and they can retain an almost circular cross section ( so the contact area between two adjacent segments is not very extended ). I think that, in such material, the properties of the "knot" itself ( the geometry ) will manifest themselves more clearly, and the properties of the particular rope ( the material ) will play a secondary only role. I also tie knots in marine ropes, but I do not judge them by how they behave there - marine ropes are usually braided, and softer ( and less slippery ) than kernmantle ropes.
Hmmm, I've found that kernmantle ropes --exactly because
the kern (often) comprises individual cords not cohesive themselves,
hence needing the mantle, are (more) compressible given that these
individual cords can spread out within the mantle.  (To me, it makes
sense to define "kernmantle" to be a "rope with a core of separate
cords or fibres not cohesive as a whole themselves", though in the
past of such-named ropes are ones with braided (cohesive) kerns.)
But, yes, often, too, there is a lot of material packed into the
mantle, and the rope doesn't like to bend --notably, e.g., the
PMI caving rope and esp. older, used specimens of that (and
Bluewater II, a like rope)!

To say that "the properties of the "knot" itself ( the geometry )
will manifest themselves more clearly" is to betray some ideal
of *knot* too biased by a particular material.  Who's to say
that sharp turns are any less belonging to knotted material
than stiffly resisted broader ones?  Indeed, I can see someone
making just the opposite charge : that stiff ropes defeat allowing
a knot to achieve its truest manifestation (as might come from
some mathematical modeling algorithm, say)!

Which is why I've remarked that we'd do some justice in giving
caution and circumspection to others by referring to not the
qualities of some "*knot*" but to "*<this_material> so knotted*".


--dl*
====
Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on June 10, 2015, 06:13:00 AM
Hi All,
       Mark I have one more here, I don't know what to call yet, have the same nipping structure with "Lee s loop"
       no sure you have any interest on this one.  It look very nice .   

       謝謝 alan lee
Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on June 10, 2015, 06:14:01 AM
Lee s loop
Title: Re: Load testing of various Bowline structures
Post by: Mobius on June 10, 2015, 10:10:33 AM
Hello mobius,

When are you planning to commence testing your Bowline structures?

I need to know because I would like to use your data (with permission) in the 'Analysis of Bowlines and other selected Eye knots' paper.

Please advise....

Thanks, Mark G

Hi Mark,

I am very busy with work commitments for two and half weeks, then I have holidays. I was planning to do trials then, especially now that "knot wars" has become a more serious undertaking and I need a more careful approach and methodology than perhaps I originally intended :)

You are welcome to use my results when I have them, they just won't be there to use that quickly I am sorry.

I need to go through this thread and look carefully at what is to be trialled and make a list. As it turns out, the two creations I would like to trial do have something to offer us anyway I think:

Mobius "Eskimo" Bowline: has a 2D turNip, however one diameter tends to hide quite a lot behind the other under load. It would not surprise me if this knot is one of the weakest trialled, however that will be interesting to find out.

B&B Bowline: technically it has a 3D turNip, yet that turNip is a large one where other component parts of the nub crowd in. Effectively, it seems bigger than 3D to me. This Bowline certainly isn't traditional in lots of ways, however trialling this knot vs other 3D bowlines might prove interesting.

Cheers,

mobius
Title: Re: Load testing of various Bowline structures
Post by: xarax on June 10, 2015, 11:44:18 AM
   Hmmm, I've found that kernmantle ropes --exactly because the kern (often) comprises individual cords not cohesive themselves, hence needing the mantle, are (more) compressible given that these individual cords can spread out within the mantle.

   All things are relative ! Kernmantle ropes are, in general, less compressible than braided ropes. Why ? Because those more or less parallel fibres/cords inside the core, are packed inside the mantle, and they are bounded by it. If the mantle encircles them tightly enough ( so there are no voids left in between them ), the rope can not be compressed easily, because a circular cross-section can not be deformed into a flattened, elliptical one of an equal area - provided that its perimeter / circumference does not change, and that the fibres/cords can not be compressed, the cross section of the mantle can not but remain more or less circular.
   Now, if the fibres/cords are able to swim freely inside the mantle  :), then yes, a kernmantle rope can be squeezed as easily as a braided one, and even more ! That was my idea of a rope made from fibres/cords arranged around an easily compressible central core ( made of some elastic material ) : this rope could be flattened very easily, and this would enable it to deform almost freely, fill the voids inside a nub, and thus maximize contact area and friction. I believe it is a common knowledge that knots tied on multi-lines, are tighter/safer than knots tied on a single line, and this was the origin of this idea of easily flattened ropes.     
Title: Re: Load testing of various Bowline structures
Post by: xarax on June 10, 2015, 11:51:50 AM
I can see someone making just the opposite charge : that stiff ropes defeat allowing a knot to achieve its truest manifestation (as might come from some mathematical modelling algorithm, say ) !

  True. I suppose that all ropes can follow a curve of even a one-rope-diameter radius - if tensioned hard enough. However, with very stiff ropes, you are right : material restricts geometry.
Title: Re: Load testing of various Bowline structures
Post by: xarax on June 10, 2015, 12:01:30 PM
There are two senses here : that of the proportion to the tensile strength; and that in proportion to manual strength.

   True. I was talking about the first, which does not depend on the size of the rope.
   However, obviously a knot tied on a rope of a larger size, can be more easily untied than the same knot, tied on a smaller size, even if both are loaded by the same percentage of its MBS - simply because the size of human fingers, and their strength, does not vary so much  :). So, let us examine/define the easiness of untiability of a knot when it is tied on ropes of some standard sizes, say, 1/2, 3/8 and 1/4 inch.
Title: Re: Load testing of various Bowline structures
Post by: xarax on June 11, 2015, 02:18:31 AM
"*<this_material> so knotted*".

 "*<this_knot> thus materialized / embodied*".
Title: Re: Load testing of various Bowline structures
Post by: Dan_Lehman on June 11, 2015, 07:24:08 AM
"*<this_material> so knotted*".

 "*<this_knot> thus materialized / embodied*".

 :D

But I think I'll have a much easier time describing
"<this_material>" than your side of that bargain!   ::)

(Though, I had mused about your take on it and seeing
*knots* modeled as biological entities and then asking
Where can they *live*? as a measure of media!?
Can the OzM_knot *live* in nylon mono. fishline?)

 :)

Title: Re: Bowline "knot wars"
Post by: Dan_Lehman on June 11, 2015, 08:36:45 AM
I am not invited to give suggestions (and really there is not any reason for it, I am only passive observer). But, I should like to include Double Bight Bowline (= Prohaska bwl = Janus bwl, one variant) in the "war".
Thx, regards
ZZ
One thing that might be worth doing --depending upon
the test apparatus, evaluation-- is making this knot
(what I called "Janus" for the like *faces* in opposite
directions) a quadruple-bight one --i.e., in the spirit
of "one good turn deserves another" but more to the
point of questioning if more diameters through the
turNip begets strength, take the tail back'n'forth
one more time, stuffing 5 diameters.  NOT that this
would be a practical knot, but simply to answer the
question about a more gradual curvature giving greater
strength.  BUT, in your testing, would we be able to
have confidence in a (single?) result?


--dl*
====
Title: Re: Load testing of various Bowline structures
Post by: xarax on June 11, 2015, 10:31:43 AM
Where can they *live* ?

  I had searched for the proper verbs, among many synonyms - and I had chosen those two ( "embodied" / materialized" ), because I had found that they are used more often than the others to denote incarnations of ( Platonic ) ideas.
  What is a wheel ? An embodied / materialized circumference of the circle - a mathematical idea, which "exists" even in a completely annihilated world without any matter left !  :)   
Title: Re: Load testing of various Bowline structures
Post by: Dan_Lehman on June 11, 2015, 07:20:42 PM
Where can they *live* ?

  I had searched for the proper verbs, among many synonyms - and I had chosen those two ( "embodied" / materialized" ), because I had found that they are used more often than the others to denote incarnations of ( Platonic ) ideas.
  What is a wheel ? An embodied / materialized circumference of the circle - a mathematical idea, which "exists" even in a completely annihilated world without any matter left !  :)   
In at least Ada programming language, the term used
for making some particulars of a "generic" subprogram
is "instantiation".

Now, a wheel vs. circle I think stands at an easy-to-figure
remove from instantiations of "*knot*", as both of the
former are round --just a question of simple imperfection
of the material thing; but re *knot*, the geometry of it
--its angles and so on (even not looking to further material
aspects of compression)-- are not so well specified by any
ideal, for the ideal doesn't consider what is though essential
for *knot* (yes?  no?) : force & tension.  (Or one has
some infinity of those ideals to match whatever turns up,
and this sort of thinking gets one nowhere, IMO!

(E.g., does The Bowline (ideal) have a turNip that contains
<what degree ...?> deflection of the S.Part & eye leg?
(esp. if SS'd  :D ).  A real one might start out that way,
and through loading, come to actually has ever so slight
a gap at this point, wanting to open the helix.)


--dl*
====
Title: Re: Load testing of various Bowline structures
Post by: xarax on June 11, 2015, 09:03:41 PM
the ideal doesn't consider what is though essential for *knot*  : force & tension

In the the "Ideal" knots I am talking about, there are no "forces" or "tensions" : the knots shrink only because their ropelength is minimized. This pure geometrical condition is enough to force them become as compact as possible ( without any compression of the "body" or change of the circular cross section of the rope ). 

does The Bowline (ideal) have a turNip that contains <what degree ...?> deflection of the S.Part & eye leg?
   Unfortunately, mathematicians have not calculated/simulated our "open" knots in their computers. For "closed" knots and links, they have made much progress. See :
   http://www.jasoncantarella.com/wordpress/software/ridgerunner/
Title: Re: Load testing of various Bowline structures
Post by: Mobius on June 12, 2015, 09:50:54 AM
Hi all,

Please don't forget to give me images (or links to images) for the knots you would like me to trial. I am a 'visual' learner, so the more you can give me to see, the better. As a new knot tyer, it doesn't take much to give me tying problems. Expanded views really help, along with advice on particular issues/preferences with regard to dressing the knot prior to load.

If I am not confident I know exactly how a knot you propose is tied and dressed properly, then potentially the trialling of my circumspect version of 'your knot' is a waste of time.

I am going to spend some time shortly and go through this thread and list the knots I feel comfortable tying properly. If the knot you proposed isn't on that list, you can probably guess why ;)

Help me out out much as possible please.

Cheers,

mobius

Title: Re: Bowline "knot wars"
Post by: Mobius on June 13, 2015, 08:49:01 AM
One thing that might be worth doing --depending upon the test apparatus, evaluation-- is making this knot
(what I called "Janus" for the like *faces* in opposite directions) a quadruple-bight one --i.e., in the spirit of "one good turn deserves another" but more to the point of questioning if more diameters through the
turNip begets strength, take the tail back'n'forth one more time, stuffing 5 diameters

I did not set out to make the exploding loop (shown below) with 5 diameters (Image 2), however it ended up that way after what I suspect might be the best dressing for the knot. An exploding loop is not a bowline, or can it be? The knot shown below certainly has a turNip and the tail does form a bight held in place by the turNip. I cannot say I am comfortable calling the knot I show a bowline though.

Quote
NOT that this would be a practical knot, but simply to answer the question about a more gradual curvature giving greater strength.  BUT, in your testing, would we be able to have confidence in a (single?) result?

--dl*
====

As a exploding loop this one might be practical. I find it easy to tie, untie after load and it appears secure after a preliminary trial. The images below show the knot did not collapse under load and the tail bight appeared to remain intact and in place. Some of these "L shaped" knots fold in half under load, this one does not. Image 3 is the knot I trialled prior to load and Image 4 is the same knot after a load of 130kg. Image 4 shows some compression of the nub, however all knots change somewhat under load and the nub geometry is still recognisable.

The knot fulfills some of the 'acronym soup' stuff as well: It is PET (post eye tiable) and TIB (tiable in the bight).

Another version of this knot, after a simple dressing change, has a 3 diameter turNip. It is a simpler looking knot, however I have not trialled this version yet.

Cheers,

mobius

Edit: Link also also shows the 3 diameter version

Link: https://docs.google.com/presentation/d/1VuospIgtPj5aG2DJIDFQGEHC0TWEYMrz8GSjaJlbPSg/edit?usp=sharing

Title: Re: Bowline "knot wars"
Post by: Dan_Lehman on June 14, 2015, 06:12:37 AM
One thing that might be worth doing --depending upon the test apparatus, evaluation-- is making this knot
(what I called "Janus" for the like *faces* in opposite directions) a quadruple-bight one --i.e., in the spirit of "one good turn deserves another" but more to the point of questioning if more diameters through the
turNip begets strength, take the tail back'n'forth one more time, stuffing 5 diameters

I did not set out to make the exploding loop (shown below) with 5 diameters (Image 2),
...
I hope that you don't feel obligated to find a practical
reason for the knot tested : again, my point was to test
the theory about gradual turns, and so adding diameters
to a common practical knot, which addition should largely
preserve the character of the knot but just vary it by giving
those extra diameters, serves this purpose best, IMO.
--rather than finding some basis for another knot and
then it would be a debatable matter whether any observed
difference was attributable to the diameters alone or to
some other different aspect!

In a similar tact, it might make sense to test a knot that
has been unusually hard set by some device --i.e., in a way
impractical--, so as to achieve a state that might shed some
light on knot workings.  (And consider that fishing knots
are usually given prescribed settings that would require
such special devices to be effected in "rope", in forces
equivalent for rope!)  And it's not that I'd expect the
result of some such testing to be "Thou shalt forever
use the SS-SuperSnugger-Model-108 on thine knots",
but insight that such conditions matter.  (At present,
we have the issue about setting a fig.8 that is
oriented with S.Part going to the far end, bearing
into its twin part vs. pulling away from it (what its
twin would were it so loaded), being set by loading
the tail --that twin part-- so as to make it unable
to be simply pushed aside, without consuming much
force from the S.Part, and maybe that offloading
makes for added strength?!  Now, in this case, I would
hope that such setting was practical, doable with manual
force.)


--dl*
====
Title: Re: Bowline "knot wars"
Post by: Mobius on June 14, 2015, 07:21:37 AM
One thing that might be worth doing --depending upon the test apparatus, evaluation-- is making this knot
(what I called "Janus" for the like *faces* in opposite directions) a quadruple-bight one --i.e., in the spirit of "one good turn deserves another" but more to the point of questioning if more diameters through the
turNip begets strength, take the tail back'n'forth one more time, stuffing 5 diameters

I did not set out to make the exploding loop (shown below) with 5 diameters (Image 2),
...
I hope that you don't feel obligated to find a practical
reason for the knot tested : again, my point was to test
the theory about gradual turns, and so adding diameters
to a common practical knot, which addition should largely
preserve the character of the knot but just vary it by giving
those extra diameters,
serves this purpose best, IMO.
--rather than finding some basis for another knot and
then it would be a debatable matter whether any observed
difference was attributable to the diameters alone or to
some other different aspect!

--dl*
====

I felt no obligation, I just happened to be playing around with 'L shaped' exploding loops and with this particular knot I thought "5 diameters, that's interesting" and remembered your comment :)

I understand that we do not particularly need 4, 5 etc... diameter turNips. The knot I showed just happened to have a large one when I dressed it a certain way (probably the best way after more reflection on it). As it turns out, it would be easy to test a 4 diameter and a 3 diameter, devolved version, of the 5 diameter exploding one I show, simply by untucking the tail. The knot's character would be preserved I think, have a look at it yourself and see if you agree.

The devolved  3 diameter case isn't exactly secure, however I suspect it would hold well enough for a trial, if I treated it carefully.

Cheers,

mobius
Title: Re: Load testing of various Bowline structures
Post by: Luca on June 14, 2015, 03:48:56 PM
Hi xarax,

A very good, simple, secure, well balanced adjustable loop. The L-shape "handle" is perfect, almost 90 degrees.

This loop is based on the same principles as the Pretzel loop and the Clove X loop :

By your description I think that you,in the first image posted by Alan at reply #56, maybe saw the loop in the image below(sorry for my beloved dirty old rope..) .In fact the image of the finished knot may be a bit ambiguous with regard of how it is built,but Alan edited his post( http://igkt.net/sm/index.php?topic=5383.msg36083#msg36083 )with new images showing that the knot is actually a fixed loop with a collar structure.

                                                                                                                                   Bye!
(http://)

Title: Re: Load testing of various Bowline structures
Post by: xarax on June 14, 2015, 04:19:50 PM
   In a way, Alan Lee "stabilized" the Girth hitch-based adjustable loop, as I had stabilized the Clove-hitch based one...
   When I had tied and tried those loops (1), I was looking for a TIB knot -(*) that is probably why I had missed them then...

  1. http://igkt.net/sm/index.php?topic=4347.0
  2. http://igkt.net/sm/index.php?topic=5357.msg36146#msg36146

(*)  Oh, my KnotGod ! This IS TIB - although its Standing Part before the eye is not ( so, it is not PET ). Thank you Luca !
      So, I should had said " I was looking for a PET and TIB knot...".
      The somehow-adjustable loop, based on a fig.8 knot tied on the Standing Part before the eye shown at (2), is also not-PEt, but TIB.
      Now, I do not remember any more which knot I saw !  :)  I wrote that Alan s Lee loop was not TIB, so, even if I had seen another knot, most probably I had NOT seen the knot you show ! You can pass the Standing Part s first curve "over" or "under" the first segment of the nub it meets. The two knots are, regarding their general shape, their nipping / gripping power and their mid-air stability, pretty much the came - however, only the one turns into a TIB knot ( which its the one you probably show - we will be sure, the moment you remove the dirt from this rope ! ) I do not know if Alan Lee has tied or shown the TIB variation - you should clarify this matter with him. For me, and for the time being, this TIB adjustable loop is called Luca s TIB adjustable loop, I am afraid...

P.S. I had thought that the adjustable loop Luca had shown was the TIB one he shows in his next post - the dirt on the ropes, and the out-of-focus picture, and my poor sight, all contributed in the tying of this knot, but the primum movens of the whole sequence of things was Luca himself.
Title: Re: Load testing of various Bowline structures
Post by: Luca on June 14, 2015, 10:23:17 PM
And I am afraid that the so-called "Luca s TIB adjustable loop" shown above is not TIB...  :( the first curve of the standing part pass "under all" in the image above(and yes,is not so clear,but at the moment I have available only the beloved dirty old rope);once removed the tail from the knot's nub,remains a Fig. 9 equivalent tied on the standing part.
So,now I am curious of the "Xarax TIB adjustable loop"...
Title: Re: Load testing of various Bowline structures
Post by: Luca on June 15, 2015, 01:56:59 AM

I have thought that the TIB variation of the so-called "Luca s TIB adjustable loop" was the one(not so stable) shown below(first pic;in the second pic I have capsized the knot in the fashion of the loop that you have shown):


(http://)
Title: ABoK#1045
Post by: xarax on June 15, 2015, 04:03:01 AM
   You were right again ( as ever !  :) ). I had mixed some files in my computer, and I had labelled wrong knots, with correct names, and vice versa ! :)
   It can capsize either in the variation you show, or in ABoK#1045.
   Your variation can be considered as a Blackwall hitch tied within an overhand knot. For a similar idea, see :
   http://igkt.net/sm/index.php?topic=4736.0
   I am not so sure that your original Luca s adjustable TIB loop, before it capsizes in the forms we show, is so unstable... We have to see how it will behave under heavy loading.
Title: Luca s adjustable TIB lkoop
Post by: xarax on June 15, 2015, 11:19:43 AM
   So, here are the pictures of the Luca s adjustable TIB loop.
   It may be a little more convoluted than minimum, and so some of its nipping / gripping power may be "wasted" inside the nub s turns, and not utilized directly to immobilize the penetrating line. We have to test all those adjustable loops, and see. However, it may be not as unstable as you think - because, with small-sized nubs, it is relatively difficult for a riding turn to slide over or under another, and settle in position significantly different that the one it was meant to. With small things, even small steps are big !  :)
Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on June 15, 2015, 12:37:45 PM
Hi All,
         I didn't tie Luca s adjustable PET loop, I like this one  is more solid, I think it will jam on heavy load, I prefer the tail tuck it on the
         other side, will make a longer collar and may support little more load, 

         The third picture, this one is more complicated to tie, but two nice collar,
         I think this one
         will do well.   Tomorrow I going to test these loop here, and give you the result.
        謝謝  alan lee
Title: Re: Load testing of various Bowline structures
Post by: xarax on June 15, 2015, 01:06:42 PM
   Noope ! Still the same problem- which you will never solve, if you do not understand it : Do NOT tie convoluted nubs when you want them to be as tight as possible / to nip/grip a tensioned penetrating line so much that they can immobilize it.
   In adjustable lops, simplicity is a functional property, it is almost a condition for their very existence ! It matters not only because, when the nub of an adjustable loop knot is as simple/less convoluted as possible, the knot can be tied and untied easily, it does not consume material without reason, it can easily be learned and remembered, and it can easily be inspected. It matters because it makes the nub tighter, and more secure ! Otherwise, a portion of the tension induced from the nipping/gripping structure will be "wasted" within its own turns, and there will remain less tension to directly immobilise the line.
   Now, the other thing you should remember ( in fact, the first thing one should realize, and keep in his mind ever since ), is the ANGLE of the L-shaped "handle", the angle at the returning eyeleg s first curve/deflexion  : It should be as close to 90, at least, degrees, as possible ! Otherwise the returning eyeleg will run the danger to SLIDE, and be dragged out of the nub. In both those loops you show in your post ( especially in the first...), this angle is too big/wide. See this angle in Luca s adjaastable TIB loop : it is 90 degrees sharp !
Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on June 15, 2015, 01:49:16 PM
Hi Xarax,

              " EASY"    The Luca s adjustable TIB loop ( loose knot ) , I don't need to test, just look at it I can tell it will jam.
                   
                                I know my loops here will work will   support heavy weight,  "IS A VALID LOOPS" why not ?

                              謝謝  alan lee

Title: Re: Load testing of various Bowline structures
Post by: xarax on June 15, 2015, 02:13:15 PM
I don't need to test the Luca s adjustable TIB loop, just to look at it - and I can tell it will jam.

   You tell it because you see the overhand knot tied on the Standing Part before the eye - and you are right, of course.
   However, it may be GOOD for an adjustable loop to jam !  :) :) Or, it may be not so bad, as to be less secure and safe - because adjustable loops are NEVER 100% secure and safe : they will slip before they break.  By jamming, it will become a safe and secure eyeknot, although it consumes a very small, only, amount of material ( because of the absence of the "collar structure" ).
   I can imagine emergency situations where we want to tie an adjustable loop, as quickly as possible, which will become as secure and safe as possible when it will be loaded, and during the time it will remain loaded, and you do not bother with what will happen later, when you will not need it any more. When the task to hold something in/with the loop has been accomplished, and the loading is not applied any more, you may even cut off the whole end of the line where you had tied the loop !  :) Ropes are not so expensive any more...  :) The immediate need/demand for a secure, safe loop, NOW, may be much more important from the demand of retaining the original length of the rope, LATER ...
   In short, I believe that, for very secure and safe adjustable loops, jamming may be an acceptable risk, and, perhaps, when the load is really heavy, it may even be desirable !
 
Title: Re: Load testing of various Bowline structures
Post by: Mobius on June 15, 2015, 02:21:48 PM
Hi Xarax,

              " EASY"    The Luca s adjustable TIB loop ( loose knot ) , I don't need to test, just look at it I can tell it will jam.
                   
                                I know my loops here will work will   support heavy weight,  "IS A VALID LOOPS" why not ?

                              謝謝  alan lee

You have trialled most of your loops from what I have read and if they work in the trial that knowledge is worth a lot. Your loops are fine Alan, keep doing what you are doing :)

Cheers,

mobius
Title: Re: Load testing of various Bowline structures
Post by: Luca on June 16, 2015, 04:05:32 AM
Hi xarax,

It can capsize either in the variation you show, or in ABoK#1045.

Yes,after manual capsizing+manipulating,the knot can be transformed in ABoK #1045!
I had not noticed this.

I am not so sure that your original Luca s adjustable TIB loop, before it capsizes in the forms we show, is so unstable... We have to see how it will behave under heavy loading.   

Well,yes,actually I meant that potentially the TIB version of the  knot has some problem regarding some accidental exchange of the position between the first curve of the standing part and the portion of rope adjacent to the first leg of the loop,and some potentially possibility of  accidental "haltering" of the portion of rope of the nipping structure that encircles the two legs of the loop.The ulterior variation of the TIB loop you show at  reply #77 seems to prevent at least the first of the possibilities described above.

With regard to the problem posed by Alan Lee at reply #78:I think that this type of adjustable loops "adjustable by the tail",if they are not designed for heavy loads(as in effect it is normally),they can afford to jamming a bit with their simple structures(but the Clove X adjustable loop perhaps jams a little too early!  ;) ).But maybe,in the hypothesis of a(static/gradual?) heavy loading a solution like this ( http://igkt.net/sm/index.php?topic=5381.msg35972#msg35972 ) seems to works even if apparently the convoluted knot in the standing part seems to prevent a total tightening of all the parts by manual force,because,applying a real load,the knot's nub actually grip around the tail,and some "redundant" portions of rope they can be used to be able to untie the knot.

                                                                                                                                  Bye!
Title: Re: Load testing of various Bowline structures
Post by: xarax on June 16, 2015, 01:52:50 PM
+ manipulating,

  I should had noticed this, indeed. Left alone, it capsizes only in the form you show - which is a pretty secure eyeknot : the Blackwall hitch within an eye and not within a rigid hook, is more secure than it looks !

a ( static/gradual ?) heavy loading

I prefer to describe this as a "slow loading".

   some "redundant" portions of rope can be used to [] untie the knot.

   In two ways : first, to offer "handles" / riding turns which can be pulled out and loosen it. And, second, by absorbing some tension which would had made it tighter !  :)  :) Nooope, I am not willing to tie a less minimal and less secure than possible adjustable loop, just to make it easier to untie ! To increase its mid-air stability, yes - such a sacrifice seems reasonable, and acceptable. So, if it turns out that the Clove X adjustable loop is much more unbalanced, in mid-air, than the double overhand knot-based one, then yes, I would prefer the later from the former- but NOT because it is more complex/convoluted, and so less tight/prone to jamming !

Title: Re: Load testing of various Bowline structures
Post by: xarax on June 16, 2015, 03:33:33 PM
adjustable loops "adjustable by the tail"

   I believe that those are the more secure adjustable loops, and the only ones which can withstand heavy loading. There is no way any nipping/gripping structure tied on the Standing End after the eye can compete them in this. For two reasons :
   First, when the nipping structure is tied on the Standing Part before the eye, it is loaded with the 100% of the load from the one side, and with 50% from the other - while, if it is tied on the Standing Part after the eye, it is loaded only by its one end, and only with 50% of the load - so it can not nip / grip / immobilize the penetrating line as efficiently.
   Second, because there is no way, in the case of the "adjustable by the Standing End" loops, to force the direct continuation of this end to make such a sharp, almost 90 degrees turn, as we can force the direct continuation of the Tail End ( which is loaded by its one, only, side ) in the case of the "adjustable by the Tail End" loops. The angle of the "handle" from which the adjustable eyeleg is hanged, is of outmost importance : An even light grip, on the tip of a 90 degrees "handle", can immobilize the penetrating line much more effectively, than even the tightest nub with the strongest grip, around a wide curve of the Standing Part.
   The only way I have managed to figure out, is the way of the "Helical loops" - but it is a very difficult to tie an adjustable "Helical loop" which, although its helical coil does not turn around its core many times ( so we can adjust its position along the Standing Part easily ), it can be as secure as the Pretzel loop, for example.
Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on June 17, 2015, 07:39:32 AM
Hi All,   Just  another adjustable loop.     
           謝謝  alan lee
Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on June 17, 2015, 10:33:13 AM
Hi All,
        This loop here can transform to another loop, see reply #157  http://igkt.net/sm/index.php?topic=4125.150

          謝謝  alan lee

        "June-21-2015 add another loop here,(second photo)this cute little knot belong to this group of knots here."
        "june-22-2015  add another cute loop (third photo).
         one more adjustable loop.(fourth photo)
Title: Re: Load testing of various Bowline structures
Post by: Mobius on June 17, 2015, 10:45:58 AM
Hi All,   Just go ahead tie this beautiful loop you self .
           Please no comment, wait till I finish writing  what I have to said, also a few more pictures to add it on here..
            and then..........
     
           謝謝  alan lee

I tied it, I am not sure I got what I was supposed to get though ;)

Cheers,

mobius
Title: Re: Load testing of various Bowline structures
Post by: agent_smith on June 17, 2015, 04:05:18 PM
Alan - I keep ending up with a 'single eye' variant of the 'Karash' Bowline... I have attached some old images I found on my computer.

Only named them 'Karash' since he apparently claims that he 'discovered' a 'TIB' version (what he calls the Karash double loop). The tying method depicted is based around #1047 but is completely unnecessary as it can be tied similarly to #1080 (by first creating an extra twist in the nipping structure). Refer this website  https://en.wikipedia.org/wiki/Karash_double_loop

Of course, I could be tying this incorrectly and arriving at the wrong result!
Title: Re: Load testing of various Bowline structures
Post by: Dan_Lehman on June 17, 2015, 06:50:46 PM
Alan - I keep ending up with a 'single eye' variant of the 'Karash' Bowline...
I have attached some old images I found on my computer.

Only named them 'Karash' since he apparently claims that he 'discovered' a 'TIB' version
(what he calls the Karash double loop). The tying method depicted is based around
#1047 but is completely unnecessary as it can be tied similarly to #1080 ...
Indeed Mr. Karash long ago submitted to me his discovery
and subsequently got it tested and presented it on his own
WWWeb site.  I likened it to doing to what Hansel&Gretel
call --pp.36/7, #197 (on Plate #11, "Bowlines")-- "the Twist
Bowline" but in a bowline in the bight variation. ["H&G" = EKFR]

There is the question of which end to load, and so on.
And one can take this foundation and go with some
"wraps" as have I & Alpineer with our locktight / tresse
barrel
knots --though, in the base, wraps do not
appear (one could regard this "base" stage, then,
as "degenerate", similarly the overhand vis-a-vis
its "multiple" forms which can have wraps but not
the simple knot base.  (And why I favor using the
starting points to counting monikers "double, treble,..."
to be "grapevine" & "strangle", for they have *one*
wrap, and fit the implications of "double" for two
and so on, unlike "double fisherman's" which has
ONE not two.)


--dl*
====
Title: Re: Load testing of various Bowline structures
Post by: xarax on June 17, 2015, 07:29:07 PM
   Alan, I had tied those three adjustable loops, but I had succeeded to "fold" into compact nubs only two of them ( the first and the third ).
   The action of the Standing Part s first curve on the penetrating line is what it should be : direct, and very efficient. However, the continuation of the returning eyeleg does not contribute to the "locking" of this line - it goes straight to the collar, so, when it comes "down" from there, the tension which runs along it has been diminished.
   The good news are :
    a, the "right" angle of the "handle", at 90 degrees relatively to the axis of the knot,
    b, that the penetrating line is squeezed, by the Standing Part s first curve, on one, or two segments placed at 90 degrees, the "right" angle ( see the red arrows in the B#W picture ).   
     We have to test all those adjustable loops under as heavy a load as they can take - and I suspect that the material would play an important role...
Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on June 17, 2015, 10:55:42 PM
Xarax, Thanks you very much.

 謝謝  alan lee
Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on June 20, 2015, 05:52:10 AM
Hi All,
       So far I see most of the simple adjustable loop, either hard to deal with or just can't handed heavy load.
       I may be wrong, unless someone show me if there is a simple adjustable loop can support heavy load. and easy to adjust the loop.

       Here I modifly the Double overhand knot-based adjustable loop little bit, and now it can support heavy load.
       eventhough is a PET loop and little more complicate to tie, but it can support heavy load and easy to adjust the loop.

       Here are some of my simple test, just a rough idea what the knot can do.
       First test, I loaded it heavy untill the Double overhand knot-based adjustable loop just start to jam.
       after the loading, the Double overhand knot-based adjustable loop,I have hard time to untie it,
       but the other one just supper easy  to untie.
       Second test, do the thing as above, have the same result.
       Third test, same loop both end, pull till it broken. and it is supper easy to untie.
       Forth test, I apply load untill I notice it just jam hard.after the loading, this loop need tool to untie it. 

       謝謝  alan lee
Title: Re: Load testing of various Bowline structures
Post by: xarax on June 20, 2015, 10:03:17 AM

    So far I see most of the simple adjustable loop are either hard to deal with, or just can't hand heavy load.
    I may be wrong, unless someone shows me if there is a simple adjustable loop which can support heavy load and it is easy to adjust the loop.

    That would had been expected. In easily adjustable loop the continuation of the returning eyeleg has to follow a not-very-convoluted path, otherwise we would not be able to pull it, and re-adjust its length. To immobilize a line like this, you need a very strong nip / grip, so you run the danger of a jamming nub...
    THAT is what we are searching ! A simple adjustable loop ( which, BECAUSE it would be simple, it would also be tight - no tension wasted between many internal turns...) which can support an as heavy load as possible, and also would not jam.

    I ask you only one thing : With those nubs which you find hard or impossible to untie, have you used the trick, to PUSH an end INWARDS, to feed the nub with more material, and so loosen it ? Of course, this is possible only with stiff, in the lengthwise sense, ropes. The ropes I use are climbing ropes, and so they are stiff : you can push one end, and they tend to be translated lengthwise like they were solid rods.

   Continue your FINE work ! There may be many non-jamming yet secure adjustable loops out there !
Title: Re: Load testing of various Bowline structures
Post by: xarax on June 20, 2015, 10:17:15 AM
   On solid braided nylon rope ( which can be elongated a lot, and which is not stiff at all, so it can not be pushed by an end...), the loops I had tied are very difficult to untie, indeed. On climbing ropes, and especially on some very slippery yet stiff(lengthwise) cannyoning ones, they are much easier.
   The very important thing I want to tell you, is something I told you already, but perhaps you have not noticed :
   You have to use a FREE REVOLVING rigid element, around which you will wrap the eye of the loop, to simulate the most common situations, where the encircled object is free to rotate around itself into the loop. This way, the tension on the eyelegs is almost equal, 50% of the load. When you do this, you will see that the nubs of some loops settle to another orientation, and the angle between the L-shaped "handle" and the axis of the loop becomes different.
   Wrap the eyelegs around a free rotating pulley, or a simple bearing.
Title: Re: Load testing of various Bowline structures
Post by: xarax on June 20, 2015, 11:50:04 AM
   There is a trade-off between, on the one hand, the number of turns of the nipping / gripping knot ( double, triple, quadruple loop ) and the angle of the L-shaped "handle" ( with more turns, the angle gets smaller than 90 degrees ), and, on the other,  the easiness with which the loop can be adjusted. I had tried the triple overhand knot, and the quadruple overhand knot, but in them this angle seemed to me to become too small, much smaller than I would had wished - so the loop becomes difficult to adjust. I have to repeat that we wish to be able to adjust the loop even under some light loading - a completely unloaded loop can be adjusted even if the continuation of the returning eyeleg follows a much more convoluted path, but then to adjust the ( length of the ) eyeleg, we will need to pull it twice, the first time from the tip of the curve the "handle" makes, and the second time from its end.
   Now, it was expected that a triple-overhand knot based gripping / nipping nub would be more easy to untie - because it is more convoluted, and, because of this, it is less tight. We have to choose between a more tight nub ( based on the double overhand knot ), and a less tight, but easier to untie one ( based on the triple or on the quadruple overhand knot ). And, as I said before, this decision by us should take into account the material we use ( a softer, more compressible, easier to be "flattened" material leads to more difficult to untie nubs ), the existence or not of some load during the adjusting stage, and what risk of jamming we are prepared to accept, in order to have an easily adjustable, yet most secure nub.
   Alan, if you want to use the triple overhand knot, pass the Tail End the way I show. Doing this, the knot becomes self-dressing, and the two segments of the rope inside the "nipping tube" can not swap positions. If you find that even this nub is not so secure as you wish, do the same thing with a quadruple overhand knot.

   P.S.
   All those loops are implementations of the idea described at :
   http://igkt.net/sm/index.php?topic=2996.msg17836#msg17836
Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on June 21, 2015, 09:37:42 PM
Hi All,
        Xarax, Thanks you very much for your comments,
        Here are few simple test on you loop, It is very nice , very easy to untie too.

         謝謝  alan lee
Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on June 23, 2015, 10:42:30 AM
Hi All,
        Mr. roo have present the HFP Slippery 8 Loop earlier, 
        see here reply #1  http://igkt.net/sm/index.php?topic=5322.0
        beside this one, I found another one here can support heavy load.

        Never mind whether it can be an adjustable loop or not. just come here for  knot Explorations.

        Beside this, I have few more loops posted it where it belong to.
        see reply #87  http://igkt.net/sm/index.php?topic=5383.75

             謝謝  alan lee
Title: Re: Load testing of various Bowline structures
Post by: xarax on June 23, 2015, 11:37:37 AM
   Never mind whether it can be an adjustable loop or not.

   I do ! Fixed loops belong to another class of loops - when I want a fixed loop, I start from the king of knots, the bowline... because it is great that this loop is PET, too, and so the knot tied on the Standing Part before the eye is not an overhand knot or a fig.8 knot, and so it can be easily untied. No end-of-line loop is as simple, as secure and as easily untied ( and in on, only, step ) as a bowline.
   It is only with the (easily) adjustable loops that we are ready to accept some difficulty in untying, or even some danger of jamming. The David Poston s loop is very secure, but can not be untied after a heavy loading as easily as the bowline ! And it can not be adjusted much easier than a common bowline - so I am not sure we can say it is an "adjustable loop" at all. The continuation of the returning / second eyeleg makes an almost 180 degree U-turn, so we can say that it follows a turn similar to the turn of the bowline s collar, and the fig.8 knot  tied on the Standing Part before the eye plays the role of a nipping structure, similar to the nipping structure of the secure bowlines ( yet not as easily untied ).
   I believe that the key to the concept of the "adjustable" loops is the angle of the "handle", the angle between the direction of the returning eyeleg and the direction of the Tail End. If it is near 90 degrees, the size of the loop s eye can be adjusted easily, even under some tension. If it is much less, the loop is not very secure, and can not withstand heavy loading. If it is much more, the loop becomes very secure, but can not be adjusted easily any more - and it can not be adjusted at all even under light, only, loading : a 180 degrees angle, a 180 degrees turn of the "handle", works like the bowline s collar : with the help of a nipping structure ( whatever nipping structure ...) , it immobilizes the returning eyeleg completely, and does not allow any easy and quick adjustment, and no adjustment at all under some load.
   To design a loop where the angle of the "handle" remains at around 90 degrees is not easy : the balance between an insecure adjustable loop and a fixed loop is delicate. The Dave Poston s loop should be compared to the common ( or the double bowline, because the fig.8-knot-based nipping structure is a "double" one ), not to the really (easily, and even some tension ) adjustable loops. 
Title: Re: Load testing of various Bowline structures
Post by: xarax on June 23, 2015, 12:27:20 PM
   We may ask : is the L-shaped "handle" the only form the continuation of the returning eyelrg can have as it enters into and exits from the nipping structure, in order to enable an easy adjustibility of the loop ?
   I have also tried the solution offered by the "Helical loops", where the returning eyeleg traces a helical path around a knot tied on the Standing Part before the eye. If the helix formed this way is not too long, it can be easiy adjusted ( but not under any load... ). Therefore the most simple "Helical loops" can be considered as a kind of "adjustable loops", indeed.
    We can also envison a loop where the continuation of the returning eyeleg can follow an S-shaped path : from straight "below" and parallel to the exis of the knot, when it goes "upwards", it turns left, then turns right, then turns left, then turns right again (or the other way around ), and then exits from the nub again parallel, or almost parallel, to the axis of the knot. In other words, where the continuation of the eyeleg is immobilized in a way similar to the way it is immobilized in the mechanical belay devices known by climbers as "racks" (1). I do not know any reliable and easily adjustable loop based on this principle.

1. http://storrick.cnc.net/VerticalDevicesPage/Rappel/JRacks.html
2. http://storrick.cnc.net/VerticalDevicesPage/Rappel/URacks.html (http://storrick.cnc.net/VerticalDevicesPage/Rappel/URacks.html)
Title: Re: Load testing of various Bowline structures
Post by: Mobius on June 24, 2015, 12:18:34 PM
This thread turned into a thread about "adjustable loops".

Those who posted about the original "knot wars" or later the suggested name change to  "Load testing of various Bowline structures" theme need not worry. I will post something in a new thread that verifies that I have acknowledged your input. I still have it mind to do the trials (as modified by reader input) I suggested in the first place.

Holidays and time to do all this (hopefully) is not far away for me :)

Cheers,

mobius
Title: Re: Load testing of various Bowline structures
Post by: xarax on June 24, 2015, 01:03:53 PM
   Perhaps the Moderators can remove the posts about various "adjustable loops", into another proper thread ? ?
Title: Re: Load testing of various Bowline structures
Post by: Mobius on June 24, 2015, 01:18:46 PM
   Perhaps the Moderators can remove the posts about various "adjustable loops", into another proper thread ? ?

Yes indeed, that would be nice. I would like to add input to a dedicated "adjustable loops" thread that I have held off adding here.

Cheers,

mobius.
Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on June 24, 2015, 06:26:42 PM
Hi All,
        Xarax, Mobius, yes it turn into adjustable loop, I felt the same way, we should do something about it.
        I suggest may be Mobius you can start a new tread just for "knots war" and left this thread alone.
        If we take away some of the reply, may make it very confuse to the reader, because all the reply is connected to one or another.
        we can change the name of this thread to what ever.
        Let  me start a new thread just for "adjustable loop"  we can gather all the adjustable loops put in one spots first, and then we test
        all of them, see if we can find any adjustable loop can be practical.

        謝謝  alan lee
               
Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on June 25, 2015, 03:01:52 AM
Hi All,
        I have another loop here, it is difference kind knot, You have to dress the loop in a very odd way
        and the nipping loop have a difference way to secure the loop.

        謝謝  alan lee.
Title: Re: Load testing of various Bowline structures
Post by: xarax on June 25, 2015, 12:56:07 PM
   You utilize the fig.8 knot just as SS369 utilized the fig.9 knots :
   http://igkt.net/sm/index.php?topic=4965.0 (http://igkt.net/sm/index.php?topic=4965.0)
   The problem with those knots is that they should be dressed carefully, otherwise the continuation of the returning eyeleg will follow a slightly different path, where it would be less well nipped, and more straightened ( so, the angle of the "handle" will be even smaller ).
   If you decide to tie a fig.8 knot on the Standing Part before the eye, I believe you have no reason not to tie the David Poston s very secure loop - or even the fig.8-based less-easily-adjustable but TIB loop, shown at :
   http://igkt.net/sm/index.php?topic=5357.msg36146#msg36146 (http://igkt.net/sm/index.php?topic=5357.msg36146#msg36146)
Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on June 30, 2015, 09:22:49 AM
Hi All,
         Just another way to tie this Lee s 8 loop.         

         謝謝  alan lee.
Title: Re: Load testing of various Bowline structures
Post by: xarax on June 30, 2015, 10:57:27 AM
  The angle of the "handle" is a little smaller that I would had wished ( about 60 degrees - I would prefer 90 degrees ), and the grip/contact between the Standing Part s first curve and the continuation of the returning/second eyeleg is a little less direct as I would had wished, but the combined effects of those two factors make a truly "adjustable" loop, indeed.
Title: Re: Load testing of various Bowline structures
Post by: xarax on July 04, 2015, 02:36:14 AM
...after manual capsizing+manipulating, the knot can be transformed in ABoK#1045 !

...which is the end-of-line loop variation of the in-line ABoK#1059 loop. They are equivalent topologically, but also very similar geometrically.
Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on July 06, 2015, 06:12:16 AM
Hi All,
         Here is another loop, very well secure and easy to untie.
         Thanks again Xarax, I like your glove.

         謝謝  alan lee
Title: Re: Load testing of various Bowline structures
Post by: xarax on July 06, 2015, 09:12:21 AM
  Here is another loop,

  A very complex ( based on a "double"= "8"-shaped crossing-knot ) nipping structure, and a very simple ( "Myrtle" ) collar structure - I would prefer the exact opposite !  :) Personally, I do not characterize the single-collar bowlines as "secure bowlines", however convoluted their nipping structure may be - even in cases where they are very stable, tight and secure structures, as in the loop presented recently by Alpineer (1). In my mind, a "secure bowline" ( or a secure bowline-like loop ) has to be as easy to untie as the common bowline, and as secure as the fig,8 loop - and the fig.8 loop is a double-collar loop !

1. http://igkt.net/sm/index.php?topic=5357.msg36132#msg36132

 
Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on July 08, 2015, 10:37:59 AM
Hi All,
        The first photo just a superficial loop, but I like the nipping structure, and I found few more home for the tail.
        Thanks again Xarax.             
         謝謝  alan lee
Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on July 08, 2015, 10:40:35 AM
  Hi All, More loops.

     謝謝  alan lee
Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on July 10, 2015, 08:42:48 PM
Hi All,
        I have two more loops here.
        Anyway Xarax have a lots of this kind of loops, but all the knots are dressed tied , I don't want to spend any more of my valuable
        time try to figure out what are these knots.
       
         謝謝  alan lee
Title: Re: Load testing of various Bowline structures
Post by: xarax on July 10, 2015, 11:28:48 PM
   Just for the record : What I had to read then, five years ago, when I dared to publish pictures of some similar knots in this Forum:
 
   Bulloney:  most if not all of these late-blooming so-called "bowlines" are lacking the quintessential element of a bowline -- viz., the central nipping loop, one end being the SPart, the other an eye leg.
   The world doesn't need such lame naming that every eyeknot that someone dreams up garners "bowline" in its moniker as some sort of claim to legitimacy.

   ( Why I believed that I should reply to such ..., I can not understand...)
------------------------------------------------------------------------------------
   However, I had published some better pictures than the ones you had gathered in your previous post, Alan !  :)
   See the attached pictures, and :
   http://igkt.net/sm/index.php?topic=4306.msg26837#msg26837 (http://igkt.net/sm/index.php?topic=4306.msg26837#msg26837)
   http://igkt.net/sm/index.php?topic=4695.msg31701#msg31701 (http://igkt.net/sm/index.php?topic=4695.msg31701#msg31701)
   http://igkt.net/sm/index.php?topic=4453.msg28786#msg28786 (http://igkt.net/sm/index.php?topic=4453.msg28786#msg28786)
Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on July 13, 2015, 08:49:33 AM
Hi All,
        Thanks for the photos and links, make it easier for me to compare your loops with my.       
        The first photo is your loop. since your loop have some similar look with Water bowline,
        Why not give them a load test, after the heavy loading on both of them, Xarax s Pretzel bowline
        holding it rock solid form, but the second collar of Water bowline was separated apart.
        and both of them are easy to untie.

        謝謝  alan lee
Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on July 13, 2015, 08:54:38 AM
  Hi All,
          Simple load test on Xarax s Pretzel bowline and Water bowline.

          謝謝  alan lee
Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on July 13, 2015, 09:56:13 AM
Hi All,
         Just a second thought, why not make it little more complicated, and little more secure.

         謝謝  alan lee
         
Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on July 14, 2015, 02:02:01 AM
Hi All,
        More load test, after heavy loading both loops holding rock solid form, and very easy to untie.

        謝謝  alan lee
Title: Re: Load testing of various Bowline structures
Post by: xarax on July 14, 2015, 04:30:36 AM
  As I had said to Alpineer (1), I do not like sharp U turns, even in first curves of the returning/second eyelegs...
  It may well be just a prejudice : other people believe they are beneficial to the "locking" of the collar structure.
  " The hard turn... helps to prevent that from feeding material into and so loosening the knot. The coil compresses tightly, for slack security ".
  1. http://igkt.net/sm/index.php?topic=5357.msg36144#msg36144 (http://igkt.net/sm/index.php?topic=5357.msg36144#msg36144)
Title: Re: Load testing of various Bowline structures
Post by: Dan_Lehman on July 14, 2015, 07:15:23 AM
  As I had said to Alpineer (1), I do not like sharp U turns,
Nor do some ropes --i.p., hard-laid ropes, old stiff ropes,
built-to-be-tough caving ropes.  In which case, one must
go to Plan B!


--dl*
====
Title: Re: Load testing of various Bowline structures
Post by: agent_smith on July 16, 2015, 12:33:13 AM
Hi Alan (Alan Lee),

I just want to personally thank you for your incredible work and contribution to our collective knowledge bank :)

I think you are an unacknowledged genius!

I will photograph some of your fantastic creations as soon as possible in high resolution format.

I am already using some of them on a regular basis...

Sincerely,

Mark Gommers
Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on July 20, 2015, 02:42:51 AM
 Hi All,
        Mark Thanks for the kind words, and the hard work. I am just a hard working knots tyer, who like to share my knots work,
        still far from genius.
        I have another interesting loop here, is a adjustable and quick release loop, only need one tuck on the tail eye leg to
        form the loop.
        Tomorrow if there is a chance during lunch break, I like to do some extreme load test with the crane.
       
        謝謝  alan lee.
Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on July 26, 2015, 06:35:27 AM
Hi All,
         For the softer rope, easy to dress the loop tight, all three test are holding very well and easy to untie.

          謝謝 alan lee.

Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on July 26, 2015, 06:37:31 AM
More photos.
Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on July 26, 2015, 06:42:36 AM

Hi All,
          For stiffer rope, because of the two one diameter rope sharp turn, just can not pick up all the slack by hand.
          7/16 Blue water rope loaded at 2000 lbs. just ok to untie, at 2500 lbs jam hard.
          8mm Blue water accessory cord loaded at 1200 lbs, one side of the loop just able to untie,  the other side jam hard.

           謝謝 alan lee.
Title: Re: Load testing of various Bowline structures
Post by: xarax on July 26, 2015, 11:09:11 AM
   As I had said many times, at the end of the day the most important thing is the angle of the "handle" ( = the angle between the returning/second eyeleg and the Tail End). If the angle is wider than 90 degrees, as it happens here, however tight is the grip, it can not be very efficient : If we do not use many ( parallel or cross-gartered)  wraps, as in the climbing friction hitches or in the rat-tail-stopper, we can not immobilize a straight line...
Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on July 30, 2015, 11:16:44 PM
Hi All,
        Xarax Thanks you very much.

            謝謝 alan lee
Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on August 02, 2015, 03:18:07 AM
Hi All,
         This is a nice looking, solid well secure double collars loop.
         The nipping loop deliver more percentage of compression force then the nipping force
         to secure the loop. Beside the standing part,  the two eye legs are able to apply pressure to the nob.   
         All three tests are holding very well, and easy to untie.
       
         謝謝  alan lee
Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on August 02, 2015, 03:20:01 AM
Load test photos.
Title: Re: Load testing of various Bowline structures
Post by: xarax on August 02, 2015, 09:53:48 AM
1. When you say "loaded heavily", what do you mean ? Could you, please specify the load as a percentage of the MBS of the rope ? Is it close to 50% ( which is what I would call "heavy load" - if it is closer to 33 %, I would call it "moderate", and if it is closer to 25%, 'light" ).
2. I would nt call it a "double collar" (=two collars) loop. The one ( the first ) leg of the collar is "coiled", that is, it makes a helical turn, but there are no two U-turns, the one after the other ( a N-like collar ). And the two legs are not crossed, like it happens in the case of the " cross-gartered" bowline (1). In particular, in the genuine "double collar" bowlines, if you, accidentally, un-tuct the second collar, you are still left with the first, which still works - while in your loop shown here... well, you are still left with a helical turn, the simplest helical "knot", which you pray it will hold ! :)
3. I am not sure that the total nipping force, delivered by the closed nipping turn tied on the Standing Part, and the open ( helical ) turn tiedon the returning / second leg of the eye, deliver more gripping / nipping power than a triple (=three nipping turns) bowline, as the Tresse coiled S.Part shown by Alpineer (2), or the even simpler Triple bowline shown by me (3)(4) - which have the additional advantage that their nipping structures are self locking. ( In fact, it looks like a transformation of those bowlines, where the one nipping turn of the "nipping structure", tied on the Standing Part has been replaced by one nipping turn of the "collar structure", tied on the returning / second eyeleg ).
4. I believe it is too complex - although easy to tie and untie. I do not see a clear "pattern" in tying it, or in its final form which would allow to inspect, memorize and remember it easily.
5. Having said that, it is clearly a new concept, where, although the loop is not based on a bend ( like the Tweedledee bowline - but there are many other, "simpler" bends not based on interlocked overhand or fig.8 knots, which can be turned into nice symmetric bowline-like loops ), nevertheless it utilizes the nipping action of both eyelegs.

1. http://igkt.net/sm/index.php?topic=4283.msg35800#msg35800
2. http://igkt.net/sm/index.php?topic=5357.msg36131#msg36131
3. http://igkt.net/sm/index.php?topic=5357.msg36605#msg36605
4. http://igkt.net/sm/index.php?topic=5418.msg36587#msg36587
Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on August 04, 2015, 07:44:14 AM
Hi All,
         Xarax Thanks for your reply, I don't have scale at home I just pull it as hard as I can, may be I should call it in between moderate
         and light then.
         Anyway I test it again with 1-4" solid braid nylon rope and 6mm Blue water rope, and also with another variation loop, this time
         I can call it close to 50% of MBS.
         Both loops are holding well and easy to untie.

          謝謝  alan lee
Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on August 04, 2015, 07:48:12 AM
Load Test photos.
Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on August 05, 2015, 08:22:24 AM
Hi All,
          This idea work on the bowline line nipping loop too.
          Interesting loop, if you just twist the top part of the bowline nipping loop it become loop 1.

          謝謝  alan lee
Title: Re: Load testing of various Bowline structures
Post by: xarax on August 05, 2015, 10:32:02 AM
   There are two ways to spoil this idea :
   First, the double coil on the returning/second eyeleg. IMHO, it is an overkill. The second helical coil will always remain more lose/less tight than the first, and it will not contribute much to the gripping / nipping of the second leg of the collar. On the contrary, it may absorb some of the tension we want to reach up to the collar, because we do mot want a lose collar either ! One may say that a second coil makes the nipping loop wider, but this is not very true : it just makes it more elongated, more oval-shaped - the Standing Part s first curve remains almost as wide as it would had been had you used one, only, coil.
   Second, to place the coil(s) horizontally, as you do, rather than vertically. A more vertically oriented coil can become more tight ( there is no tension "wasted" by the generation of friction forces within its segments, due to unnecessary twists ), while, at the same time, it allows the incoming tension to pass through it, and reach the collar. You need this coil to grip / nip as tightly as possible, but to remain a "nipping loop" ( that is, a loop with two ends almost equally loaded ), not a half hitch !
   I believe you had tied a loop like the one shown in the attached pictures in the past. Your collection has gone out of the roof, you need some housekeeping ! ;)
Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on August 08, 2015, 08:27:22 AM
 Hi All,
        Xarax Thanks for your reply, I have the load test here, it is a rock solid well secure loop, and very easy to untie.
        Part of top coil will slowly jam into the bottom coil as the load increase, there is nothing loose in the nob.
        In order to have a nicer main collar, When we load the loop, we may have to hold some tension on the tail till the
        nipping force get hold of the tail.(because this nipping force are little slow to reach to the tail).

           謝謝  alan lee
Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on August 08, 2015, 08:31:45 AM
load test photo.
Title: Re: Load testing of various Bowline structures
Post by: xarax on August 08, 2015, 09:02:47 AM
   Indeed, I see in your pictures that the diameters of the two coils are equal, which means that there remains no slack in the nub. I had not loaded your loop so much, and that is why the second / higher collar remained more loose.
   However, I still believe this second collar is an overkill. We use two collars when we want the friction between their parallel and adjacent wraps to keep them "locked" - but here you have the nipping loop itself to do this. I do not believe that two collars grip / nip / immobilize a penetrating line more than a single one ( and, in any case, such an effect, if it exists, it has not been demonstrated by any test, ever ) - because one single collar "bites" harder into the surface of the line, but two, although they provide a more extended area of contact, they also provide a more extended area on which a line can slide, because they can not penetrate into its surface so deep.
   I think that if you tie the much simpler knot I had shown in my previous post ( with the vertically oriented coil, which is loaded more directly by the returning/second eyeleg ) you will see that it is no less tight and secure, although it uses one, only, collar. 
Title: Re: Load testing of various Bowline structures
Post by: xarax on August 10, 2015, 01:06:26 PM
   On the other hand, anything hanging from the rim of the nipping loop ( like this/those turns on the returning/second eyeleg, before the collar ) tends to pull the nipping loop wide open - so, perhaps, what this eyeleg gains, regarding friction, in its way "up, it loses it in its way "down" - because the "loaded" nipping loop may not be able to nip it as tightly as when it was left undisturbed...
Title: Re: Load testing of various Bowline structures
Post by: Mobius on September 23, 2015, 01:24:02 PM
This thread started life as a fun 'knot wars' idea.

Later it metamorphosed into a thread about adjustable loops :)

For several weeks I was not around here so that didn't help much either. At some stage I will try and pull the bones out of it and do something along the lines of what I intended. My new test rig is both good and bad, I can test much bigger loads, however the finer detail of when a knot breaks (i.e. what %mbs) disappears in the press of a button.

Where a knot breaks is more interesting anyway perhaps, and is not so much to do with the 2 diam vs 3 diam debate from what I have seen.

Cheers,

mobius
Title: Re: Load testing of various Bowline structures
Post by: alanleeknots on September 25, 2015, 02:18:56 AM
唯恐天下不亂嗎?
Title: Re: Load testing of various Bowline structures
Post by: Mobius on September 26, 2015, 08:21:37 AM
唯恐天下不亂嗎?

Hi Alan,

If that was a question for me, in Chinese doesn't help me much answering it ;D

Cheers,

mobius
Title: Re: Adjustable Loops
Post by: Mobius on September 27, 2015, 09:31:20 AM
From another thread:

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

Thanks, I was almost sure the knot I came up with was one I had seen before.... one of yours :)

Is the 'Triple overhand knot-based adjustable loop' the best one you found? If not, what was better?

I played some more with the Double overhand style loop you first showed us and added a second collar. The collar is more about introducing a 3rd diam through the turNip to see if that lessened the double overhands jamming potential while still allowing enough nip. Here is what I found happened:

Image 1 left: A simple double overhand double collar which slips, so reject this one. The 3rd diam did not look promising

Image 1 right: The tail is tucked in one of several possible ways. The knot tails loads to an 'L' shape at 500kg and didn't jam. However the collar closest the eye was too loose for my liking so I reject this one too. The 3rd diam. idea seems to work better this time

Image 2: Another try at re-tucking the tail. The tail becomes an 'L' under load

Image 3: Under load at 500kg. It untied easily in my rope (messed up the focus a bit, sorry). There are no loose bits in the nub, the collars and other loops are doing something load wise and nub form looks good to me. The 3rd diam through the turNip need not be dismissed it seems.

Seen any of these double overhand adjustable loops before Alan? The last one looks ok, what do you think?

Cheers,

mobius

Edit: added a 4th Image, much better focus of the same knot as Image 3 at 500kg
Title: Re: Adjustable Loops
Post by: alanleeknots on September 28, 2015, 06:03:59 AM
Hi All,
         Mobius Thank you very much for fixing the thread problem. Since you ask me about you knot, and I owe you a favour.
        I try my best to answer you. The additional collar will lengthen the collar near the standing part
        and also the three rope diameter on the nipping loop can push the main collar more upward,
        that mean we have a nice main collar and easy to untie.
        Now the main collar is fine, but there is a problem, additional collar will lock on the the nipping loop.
        When you load the loop,for softer rope it will lock on early, for stiffer rope can hold better, but it will jam on heavy load.
        unless you dress the additional collar loosely,then it will not jam on you.
        My own opinion any good knots should dress it as tight as you can before you use.
           謝謝  alan lee.
Title: Re: Adjustable Loops
Post by: Mobius on September 28, 2015, 06:56:54 AM
Hi All,
         Mobius Thank you very much for fixing the thread problem. Since you ask me about you knot, and I owe you a favour.
        I try my best to answer you. The additional collar will lengthen the collar near the standing part
        and also the three rope diameter on the nipping loop can push the main collar more upward,
        that mean we have a nice main collar and easy to untie.
        Now the main collar is fine, but there is a problem, additional collar will lock on the the nipping loop.
        When you load the loop,for softer rope it will lock on early, for stiffer rope can hold better, but it will jam on heavy load.
        unless you dress the additional collar loosely,then it will not jam on you.
        My own opinion any good knots should dress it as tight as you can before you use.
           謝謝  alan lee.

Thanks for the feedback. I will try my double collar knot (the last one shown) in both my 3mm poly braid and 6mm marine grade pe/pp blend and see if it jams. The 3mm poly braid I use likes to jam (it's size makes it hard to untie even if it is smooth and stiff) and so does the frictive surface of the 6mm marine 3ply (very stiff). I don't test in soft rope, so lots of knots would jam in softer rope that otherwise would not in stiffer rope I suppose.

We may need different knots for different ropes, especially when it comes to adjustable loops.

Cheers,

mobius.
Title: Re: Adjustable Loops
Post by: alanleeknots on September 28, 2015, 08:22:36 AM
Hi All,
        Yes or no,  knots would jam in softer rope that otherwise would not in stiffer rope,  knots also would jam in stiffer rope
         that otherwise would not in softer rope.

         謝謝  alan lee.
Title: Re: Adjustable Loops
Post by: Mobius on September 29, 2015, 12:32:16 PM
Just to follow up on what I said I would do. Below are some 'other material' trial images of the double overhand, double collar adjustable loop I proposed earlier.

It actually works far better than I thought it would when I first started playing with it. That the 3 diams allow the turNip to hold as well as it does was a surprise. Then I was pretty sure Alan would be right and the eye collar would jam once I got it under heavy relative load (50% mbs) rather than the 500kg (20% mbs) load I tried before. However, the knot still looks very good to me: Doesn't slip, doesn't jam, doesn't deform under load.

The 3mm poly I use is shown at >100kg and the 6mm pe/pp is >300kg. Both images 2 & 3 show the knots were tight. I could get both knots apart by hand after these loads with relative ease. The collar closest the eye was the hardest to loose (as Alan said it would be), however I still think the knots were what I consider as being 'easy to untie'.

I have some reasons why this DODC Loop seems to work as well as it does, however those can wait for now.

Cheers,

mobius
Title: Re: Adjustable Loops
Post by: alanleeknots on September 30, 2015, 08:05:02 AM
Hi All,
         Mobius, let said we have a standard bowline here, we add one or two tuck or may be a second collar to the nub, by doing that,
         we have to gain something, have to be better then the standard bowline, otherwise it don't make sense to have though those unnecessarily
         parts add in to the nub. Any way I like your effort.
         謝謝  alan lee
Title: Re: Adjustable Loops
Post by: alanleeknots on January 06, 2016, 10:01:12 AM
Hi All,
       Happy New Year
       Here is another variation of loop that belong to the same class and I didn't post it the last time,
       see here reply #128  http://igkt.net/sm/index.php?topic=5383.120 , because the last three loops their rope flow in to the nub are smooth
       then this one here.
       Now I have more free time to look at it again,I think this loop is not that bad at all. this loop is well secure and easy to untie,
       and the tail of this loop was nipped by the top collar with full force, make it little more secure.
       It is important have the last defend as Xarax alway said.
       
       謝謝  alan lee
Title: Re: Adjustable Loops
Post by: Dan_Lehman on January 06, 2016, 05:26:09 PM
Just to follow up on what I said I would do. Below are some 'other material' trial images of the double overhand, double collar adjustable loop I proposed earlier.

Heinz Prohaska proposed using the anchor bend structure
qua eye-knot base some decades back, in response to the
infamous Lynn-Hill accident (where she was distracted from
tying in and simply didn't tie her intended (per her book)
bowline, but which some (mis)took as the case where
a left-in-rope-for-next-tying fig.8 (single-strand, SPart)
awaited the new tyer-in person's "rethreading" to complete).
So <whew>, Heinz thought that this base is one that could
work even if only the first tucking-tail-into-knot was done
and nothing further!
(IMO, that is fine-tuning an error point to a too-small range.)

Perhaps if the additional loop around the SPart is made
away from the eye --so that it will press into the other--,
jamming will not occur (or as much) ?!


--dl*
====
Title: Re: Adjustable Loops
Post by: Dan_Lehman on January 06, 2016, 05:34:11 PM
Hi All,
       Happy New Year
Yes, thank you --and may it be so!
(but rumblings all over this world are worrying)

Quote
... this loop is well secure and easy to untie,
and the tail of this loop was nipped by the top collar with full force, make it little more secure.

Hmmmm, the severe curves in the S.Part worry me,
and it stands thus in sharp contrast to a somewhat
similar-looking "locktight" eye knot --and one that
Alpineer also formed, naming it "...tresse...".  Although
the knots I present here

http://igkt.net/sm/index.php?topic=4476.msg29741#msg29741 (http://igkt.net/sm/index.php?topic=4476.msg29741#msg29741)

show a pretty sharp U-turn for the S.Part, so too does the
blood knot which nevertheless seems to fare well
in nylon monofilament --and breaks, per Barnes, not at
those turns but in the center where S.Parts pass on either
side of the nipped tails (!).

(One of those locktights has a broader collar for the sake
of stiff, low-elongation ropes (I think I was fiddling with some
well-used Bluewater II, which resists bending!).'  I like to put
the tail so that IT is what the severe turn of the S.Part bites
into (as the tail lacks tension and so can deform under such
pressure, which I presume is beneficial to the SPart).
)


--dl*
====
Title: Re: Adjustable Loops
Post by: Mobius on January 26, 2016, 07:48:00 AM

Perhaps if the additional loop around the SPart is made
away from the eye --so that it will press into the other--,
jamming will not occur (or as much) ?!


--dl*
====

I think the first image below is one way to revise the double collar knot I showed a few posts ago. A good suggestion from DL I believe, I will trial this revised knot in due course. I like the way I feed the tail through the nipping turn, but there may be better ways to do it. I don't think this knot will jam as I show it.

Image number two is a PET eye knot that to my mind can still be called 'adjustable'. A moot point perhaps. I have trialled this knot in a  preliminary fashion and it does hold at 200Kg in dynamic rope so far. The collar around the eye can be left loose, the knot appears to be secure regardless.

Image three is both PET and TIB. It holds at 200Kg in dynamic rope as well. Note that for TIB to be a significant attribute, I believe an easy TIB tying method also needs to be available. Easy to me means: the knot can be held in your hands and tied in total darkness in less than 30 secs (eye knot). 30 secs is probably generous, but I hope you get the idea of what i mean by 'easy'.

None of these images I claim as new.... Alan Lee (in particular)  has a lot of knots out there, some of which I recollect as at least being similar :)

Cheers,

mobius
Title: Re: Adjustable Loops
Post by: Mobius on February 20, 2016, 08:38:35 AM
(I think my camera is playing up, nothing I do achieves focus... sigh)

The first left-hand image is the one Alan first proposed. The second right-hand one is a variation that may also have been shown by Alan Lee. Regardless of where the knot version started I thought I would share with you that the image on the right is probably better to use.

I have used this style of adjustable knot a lot on my rig.  The knot on the left has jammed under 200-400 kg load in dynamic rope while the version on the right has always behaved itself to date. Possibly jamming was an aberration, however I am not in a hurry to waste good rope finding out for sure.

From a practical user's perspective, I only use the right-hand version now.

Cheers,

Ian
Title: Re: Adjustable Loops
Post by: alpineer on February 20, 2016, 09:44:25 AM
(I think my camera is playing up, nothing I do achieves focus... sigh)

Pull the batteries for a bit, then re-install to reset camera.
Title: Re: Adjustable Loops
Post by: Mobius on February 21, 2016, 05:38:29 AM
(I think my camera is playing up, nothing I do achieves focus... sigh)

Pull the batteries for a bit, then re-install to reset camera.

Thanks for the advice, though it did not work for me (see image in my 'offset' post). Maybe I just need an idiot-proof camera ;)

With that in mind, I asked for an early birthday present and my wife is getting me a new Nikon Coolpix 840. Good? I don't know, however it has to be better than what I have been struggling with to date, a 10 year old Sony 5.1 3X Cyber-shot.

Cheers,

Ian
Title: Re: Adjustable Loops
Post by: alanleeknots on February 21, 2016, 08:39:19 AM
Hi All,
       Mobius ,I have put together a few pictures here, you will find which one have a better collar near the standing part.
       A loop will jam or not, most of the time is govern by how the main collar set up (if there is the only collar with the loop).

       Fourth picture is TIB Adjustable loop, it can be tie in one continuous motion like the "Quick tie TIB Scott's locked bowline", 
       with half a step less effort.  This loop may find little hard to tie it with PET method.
       I only test it with medium load and it perform very well, I think it will do well with heavy load.
       Related links, Reply #31 and Reply #34  http://igkt.net/sm/index.php?topic=5444.msg37446#msg37446
                             Reply #13  http://igkt.net/sm/index.php?topic=5322.0
                             https://www.youtube.com/watch?v=cfgN2EPfxH8
       This loop also can transform to Quick tie TIB Scott's locked bowline.
        謝謝  alan lee.
Title: Re: Adjustable Loops
Post by: Mobius on February 21, 2016, 09:04:53 AM
Memory has played tricks on me it seems. Alan came up with the version that does not appear to jam, whereas the other one might have more problems (and maybe the one I came up with, lol).

I will try xarax's version sometime soon.

Is there a simple PET (post eye tiable) adjustable knot? We were shown one somewhere I think (that does not fall apart). If not, I will work on one.

Cheers,

Ian.
Title: Re: Adjustable Loops
Post by: Dan_Lehman on February 23, 2016, 06:54:20 PM
Is there a simple PET (post eye tiable) adjustable knot?
One can see this, conceptually, at least, in two knots:
the venerable "midshipman's loop" --which is a noose
hitch (hoped to be non-sliding, though) formed by
tying the tail to the structure's S.Part with some
variation of rolling hitch;
then one could put a Prusik hitch coil in the S.Part
and reeve the tail through this (surety could come
by tying off the tail further (stopper, e.g.) after
adjusting the size of the eye (which in a sense
is indefinitely adjustable given that the overall
knotted structure is PET and so can await the
rough sizing of the eye to do anything tying-wise).

In the books already is something called "the crabber's eye
knot"
in which a (I might be mistaken in recall here!)
marlinespike hitch --or similar-- is formed with the tail
around the S.Part and only set into secure form upon
reaching the desired eye size.  (The harsh bending of
the S.Part doesn't appeal to me.)


--dl*
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