Author Topic: Eight-Shaped Post-Eye Tiable Loop Knots  (Read 2360 times)

alpineer

  • Sr. Member
  • *****
  • Posts: 511
Eight-Shaped Post-Eye Tiable Loop Knots
« on: February 24, 2020, 04:32:35 AM »
Sometime back in late summer/fall of 2018, I had an idea to integrate a Double Yosemite finish into the nipping loops of the Double Bowline and the Tresse Bowline respectively. Driven by my search to find a new Post-Eye Tiable knot for tying into a climbing harness, the idea quickly turned into a project resulting in the creation of several more knots.

All of the knots were created using the 8-shaped 'elbow' forms of the Double Bowline or the Tresse Bowline. The W.End, after going around the S.Part in one direction or the other to form the collar, used the elbow's form to trace any one of several discreet paths and create each new knot. Each knot presented with tails exiting either alongside the S.Part or alongside the EyeLoop's first leg, except in the symmetric knot cases, where the tails exited out of the knot sans host.

In order to qualify as a harness tie-in knot, each knot would have to demonstrate bombproof security, easy tying, and 'hands only' untying after repeated heavy loading.

After months of fiddling, tying and untying with and without a harness, I chose the 'virtual' Bowline having a Z-over-S (tresse) elbow and a #1010 collar with the WE returning directly through the front loop only and tracing the elbow's path back through the knot to exit through the collar alongside the SP. If the measure of a good knot is a function of the material its tied in and the right balance of attributes and compromises for the intended purpose, this is my PET knot of choice for tying into a climbing harness. I have effectively ended my search.

To test whether my chosen knot could be untied by hand after being subjected to a heavy load, I made use of two fork lifts (one parked and one pulling). A test specimen was tied at one end of a length of climbing rope and an F8 was tied at the other end. The eyeloops were connected to pins at the rear of each fork lift. The plan was to load the line as severely as possible - without causing catastrophic failure of either knot - and render the F8 untiable and attempt to untie the test knot by hand. The test results proved the F8 to be impossible to untie. Where the test specimen was tied, the rope suffered a core shot, yet I was able to easily and quickly untie the knot using hands only.

Photos and a video of the best way to tie into a climbing harness with the knot will follow at some point.
« Last Edit: February 25, 2020, 10:13:25 PM by alpineer »

agent_smith

  • Sr. Member
  • *****
  • Posts: 1391
Re: Eight-Shaped Post-Eye Tiable Loop Knots
« Reply #1 on: February 24, 2020, 11:23:18 AM »
I'd like to see a clear photo of your creation.
I would also comment that the concept of an 'elbow' can be problematic - and many illustrations don't point with precision to the alleged 'elbow'.

Oftentimes, authors point to what is actually a loop - which has a defined chirality (either Z or S). More to the point, the alleged 'elbow' might be the space created between 2 overlaps which is a continuation of the initial loop (eg the twist method of forming a #1053 Butterfly.

Anyhow, please provide some photos for analysis.


Keystoner

  • On Walkabout
  • Full Member
  • ***
  • Posts: 96
Re: Eight-Shaped Post-Eye Tiable Loop Knots
« Reply #2 on: February 24, 2020, 08:09:05 PM »
Photos and a video of the best way to tie into a climbing harness with the knot will follow at some point.
"At some point"?  ::)
Nice teaser.

Dan_Lehman

  • Sr. Member
  • *****
  • Posts: 4072
Re: Eight-Shaped Post-Eye Tiable Loop Knots
« Reply #3 on: February 24, 2020, 11:57:33 PM »
Sometime back in late summer/fall of 2018, I had an idea to integrate a Double Yosemite finish into the nipping loops of the Double Bowline and the Tresse Bowline respectively. Driven by my search to find a new Post-Eye Tiable knot for tying into a climbing harness, the idea quickly turned into a project resulting in the creation of several more knots.

All of the knots were created using the 8-shaped 'elbow' forms of the Double Bowline and the Tresse Bowline. The W.End, after going around the S.Part - in either direction - to form the collar, used the elbow's form to trace any one of several discreet paths and create each new knot. Each knot presented with tails exiting either alongside the S.Part or alongside the EyeLoop's first leg, except in the symmetric knot cases, where the tails exited out of the knot sans host.
Now, you (et al.) know that I'm a "words can work" guy,
who is often scolded here for lacking (jpeg) images,
but I'm not getting anywhere much from these words.
If we had a better starting point (image from past posts)
and some clearer then-whats, maybe we'd progress.

Note that the fig.8 can serve as a base for your design
goals, IMO --i.e., a slip-knot version (to be PET, you see)--,
with a simple bowlinesque collaring.  (But to your point about
"the material it's tied in" --an aspect too seldom respected(!)--,
I'm now fiddling in small nylon solid braid and not a firmer
stuff better modeling the intended kernmantle!)

Quote
After months of fiddling, ...
Is your mind sore?   ;D

Quote
tying and untying with and without a harness
Btw, how *comfortable* is your harness (or h--es) with
a double-eye, a 2nd pass through the tie-in loops?
Because it's a simple solution to tie-in security as you
know (per German climbing choice of BoaB), there's
some merit to this easy redundancy, with any loosened
untying (i.e., unintended!) presumably having an
initial state of ONE untied eye's material flapping
around in alarm.

Quote
... the WE returning directly through the front loop only
 and tracing the elbow's path back through the knot
 to exit through the collar alongside the SP.
This SOUNDS as though the *tresse*-ing part of the
knot --and the initial turning of the SPart-- comes
around but a single diameter/strand ?!

 If the measure of a good knot is a function of the material its tied in and the right balance of attributes and compromises for the intended purpose, this is my PET knot of choice for tying into a climbing harness. I have effectively ended my search.

Quote
the F8 to be impossible to untie.
*Interior- or exterior*-loaded?
And did you try hammering the knot (hoping
that some of these shocks would bit-by-bit
loosen it --a method rumored to be useful)?

Quote
Photos and a video of the best way to tie into
 a climbing harness with the knot will follow at some point.

Thanks much!

(-;

alpineer

  • Sr. Member
  • *****
  • Posts: 511
Re: Eight-Shaped Post-Eye Tiable Loop Knots
« Reply #4 on: February 26, 2020, 02:43:31 AM »
https://igkt.net/sm/index.php?topic=4321.0

Get some cord and tie the knot loose as in OP jpeg #3, but don't take the tail through the second loop. Give yourself extra tail to work with. This is your starting point for making the new knot. With tail in hand, just follow the shape of the elbow in a counter-clockwise motion until it exits through the collar alongside the S.Part. Don't overthink what you're doing here.You're simply following the shape of elbow's path in reverse until the tail is reversed completely out of the knot.
« Last Edit: February 26, 2020, 03:58:53 AM by alpineer »

agent_smith

  • Sr. Member
  • *****
  • Posts: 1391
Re: Eight-Shaped Post-Eye Tiable Loop Knots
« Reply #5 on: February 26, 2020, 04:13:53 AM »
Despite Dan Lehman's assertions that "words can work" - there are several possibilities arising from your description.
A photo provides 100% clarity and removes any lingering doubt.

Again - you use the term 'elbow' - which is problematic.
I don't think anyone has attempted to provide a clear and unambiguous definition of precisely what an 'elbow' is.
It seems to be parroted from one knot book to the next.

Budworth has used the descriptor "linked elbows" in some of his books.
Again, he seems to miss the fact that one of his alleged 'elbows' is none other than a loop (with either S or Z chirality).
I think Budworth is attempting to describe the space formed between 2 consecutive crossing points (ie overlaps) - eg as with the twist method of tying #1053 Butterfly.

Ashley's definitions at page 13 (ABoK) are not helpful, and in fact add some confusion to defining precisely what a 'loop' is. Ashley doesn't appear to have a notional concept of chirality - and that all 'loops' have a defined chirality (S or Z).

In any case, I've had a crack at following your written description and came up with an end result but; I am reluctant to cast judgement on account of not being absolutely 100% sure that what I have tied precisely matches your intent.

Again - photo please!

EDIT NOTE: You would be hard pressed to come up with a Bowline variation that matches the simplicity and effectiveness of Scott's locked Bowline.
It is inherently secure and has 3 rope diameters inside the nipping loop. It can be tied from #1010 or #1034 1/2.
It is easy to learn and remember. It is also resistant to circumferential loading (ie ring loading).

Your original 'Tresse Bowline' is vulnerable to circumferential loading and the power of the nipping structure is reduced on account of the U turn induced at the ongoing eye leg.
The nipping structure isn't directly based on a single or double helical loop and so I am hesitant to call it a 'Bowline' - rather a 'virtual Bowline'.
I see the nipping structure as being comprised of a loop with S chirality and a superposed U turn.
It is nevertheless an interesting creation - and somewhat vaguely reminds me of nipping structures formed from a #206 Crossing hitch (eg Karash virtual Bowline).
« Last Edit: February 26, 2020, 04:43:35 AM by agent_smith »

alpineer

  • Sr. Member
  • *****
  • Posts: 511
Re: Eight-Shaped Post-Eye Tiable Loop Knots
« Reply #6 on: February 26, 2020, 04:01:20 PM »
Quote
Note that the fig.8 can serve as a base for your design.

But it won't have the shape/pattern to properly trace the tail fluidly back through the knot.

Quote
Btw, how *comfortable* is your harness (or h--es) with
a double-eye, a 2nd pass through the tie-in loops?

Works fine with the Petzl Corax.

Quote
This SOUNDS as though the *tresse*-ing part of the
knot --and the initial turning of the SPart-- comes
around but a single diameter/strand ?!

Sounds as though, but in fact no. The tail will follow the elbow's path and eventually enter that part of the knot, but from the opposite to normal side and in the opposite direction. So the S.Part's initial turn does come around two strands, albeit the tail strand is at an oblique angle to the eye strand. What effect this might have on the S.Part... any thoughts?

Quote
*Interior- or exterior*-loaded?
And did you try hammering the knot (hoping
that some of these shocks would bit-by-bit
loosen it --a method rumored to be useful)?

The F8 was interior loaded, arbitrarily.
And yes. I took a hammer to it with absolutely no effect. You'd have trouble cutting with a knife.
I've kept the specimen and I'll soon post an image with another F8 alongside - tied and hand-set in the same material - for comparison.

Quote
Is your mind sore?   ;D

The mind is fine, Dan. Thanks for asking.
« Last Edit: February 26, 2020, 04:20:42 PM by alpineer »

Keystoner

  • On Walkabout
  • Full Member
  • ***
  • Posts: 96
Re: Eight-Shaped Post-Eye Tiable Loop Knots
« Reply #7 on: February 26, 2020, 10:50:36 PM »
This is a useless thread without pictures.

Dan_Lehman

  • Sr. Member
  • *****
  • Posts: 4072
Re: Eight-Shaped Post-Eye Tiable Loop Knots
« Reply #8 on: February 26, 2020, 11:13:28 PM »
Quote
This is a useless thread without pictures.
Usefulness is a verbal potential; don't give up soooo
quickly!
Now, I'm with Agent_Smith re "elbow" : I know this
in pasta, not knots.

But the additional tying guidance leaves one at a point
without many choices to be confused by or to try.  Let
ME make some better words, as *I* see it (so far).
Btw, what happened to what sounded like MULTIPLE
fig.8s in the knot --to wit, " I had an idea to integrate
a Double Yosemite finish into the nipping loops
of the Double Bowline" ??  Now, we're only getting this
in (a) single dose & (b) appearances, not a true fig.8! !?

As I read them, your words have the knot as per OP#3
and the returning eye leg (red part) has gone as shown
through making the U-turn to collar the S.Part, then
crossing OVER the crossing point of the S.Part and
outgoing eye leg (blue-green), parallel now with
the returning (red) eye leg through a bight of the
bluegreen rope BUT NOT OUT THE BOTTOM turn/loop
of this.
And the point of departure here is that the tail
is to now trace --going anti-clockwise-- the S.Part's
course into the knot (tail tracing back out ...),
AND TO DO THIS it crosses UNDER itself immediately,
in tracing, lying beside the S.Part out through the collar.

THIS LOOKS LOUSY for leaving the S.Part making
a single- diameter u-turn,
the tail to also hew to a single-dia. turn in its
tracing the S.Part back out.
Really?!?!?!?

Heck, just tie a EBDB and call it a day!

 ;)

alpineer

  • Sr. Member
  • *****
  • Posts: 511
Re: Eight-Shaped Post-Eye Tiable Loop Knots
« Reply #9 on: February 27, 2020, 08:55:18 AM »
https://photos.app.goo.gl/UbAP6T2sf7zQyPV3A
Click on this link to view some images.
Swipe left to scroll.
Blue rope shows loaded F8 w/unloaded F8 alongside for comparison.
Standing End in tying sequence set is upper green.
« Last Edit: February 27, 2020, 09:03:15 AM by alpineer »

alpineer

  • Sr. Member
  • *****
  • Posts: 511
Re: Eight-Shaped Post-Eye Tiable Loop Knots
« Reply #10 on: February 27, 2020, 11:03:26 AM »
Re Elbow,
As everyone knows,  many parts of the human anatomy are used to define or describe things.
There IS but one clear, unambiguous and reasonable explanation of what an Elbow is. Technically speaking, it's the oblique crossing part that separates any two adjacent loops formed by twisting a bight. However, in the common practical sense, "elbow" is used as a synecdoche to refer to the whole affair.


 
« Last Edit: February 27, 2020, 11:16:57 AM by alpineer »

Keystoner

  • On Walkabout
  • Full Member
  • ***
  • Posts: 96
Re: Eight-Shaped Post-Eye Tiable Loop Knots
« Reply #11 on: February 28, 2020, 01:28:35 AM »
https://photos.app.goo.gl/UbAP6T2sf7zQyPV3A
That's 8,000 words right there. Those step-by-step pictures are perfect. Thank you.
« Last Edit: February 28, 2020, 01:31:07 AM by Keystoner »

Keystoner

  • On Walkabout
  • Full Member
  • ***
  • Posts: 96
Re: Eight-Shaped Post-Eye Tiable Loop Knots
« Reply #12 on: February 28, 2020, 04:59:33 PM »
<SNIP>
That's not the topic of this thread. There is an entire thread by @agent_smith and his paper right here: https://igkt.net/sm/index.php?topic=4480.0
« Last Edit: February 28, 2020, 05:01:03 PM by Keystoner »

KnotLikely

  • Full Member
  • ***
  • Posts: 26
Re: Eight-Shaped Post-Eye Tiable Loop Knots
« Reply #13 on: February 28, 2020, 07:44:20 PM »
My apologies, Keystoner.  I figured posting in a thread from 2013 would be considered a necro.  I guess this board does not bump replied to posts.

I'll repost the relevant part and attempt to explain it in a different way and with pictures.

alpineer's knot is a ZS (left hand loop placed under right hand loop) bowline where the working end, after making the collar, enters only the secondary (Z) nipping loop and exits the nipping structure before going through the main nipping loop.  The working end then proceeds to trace the main (S) nipping loop back toward the Spart.  This knot, after repeated loading and unloading devolves into this:

https://i.imgur.com/vkaaQkc.jpg
https://i.imgur.com/i5ETClQ.jpg

It is not secure and it is not stable.  I don't see it as a practical knot.
« Last Edit: February 28, 2020, 07:46:13 PM by KnotLikely »

Keystoner

  • On Walkabout
  • Full Member
  • ***
  • Posts: 96
Re: Eight-Shaped Post-Eye Tiable Loop Knots
« Reply #14 on: February 28, 2020, 08:21:44 PM »
No worries. I'd encourage you to post everything that you've deleted from this thread to that thread. I suspect @agent_smith and others would be happy to address it. The thread may have been started in 2013 but the last post was in August of '19 and @agent_smith typically posts updates in that thread when he updates his article. That's where I go when I'm checking for updates.

Thanks for the pics and discussion of Alpineer's creation.