Author Topic: Appropriate bowline knots for rock climbing  (Read 4739 times)

Davide Fossati

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Appropriate bowline knots for rock climbing
« on: September 01, 2020, 01:24:56 AM »
Hi everyone!

I have a few questions regarding the types of bowline knots that are appropriate for rock climbing. Until now I always used the traditional "retraced figure-8" knot to tie into my climbing harness. However, I recently started to practice repeated lead falls, and I decided to learn about bowlines because of their "jam-free" property. I found Mark Gommer's excellent paper: "Bowlines Analysis" version 2.9f (posted at http://www.paci.com.au/knots.php), and I read it carefully. There is a lot of great information in Mark's paper! Here are my questions:

1) Is there a document that shows the step-by-step process to tie all the inherently secure knots shown at page 77? I managed to "reverse engineer" the process to tie the Scott's locked bowline (both versions: "tail inside eye" based on #1010, and "tail outside eye" based on #1034 1/2) from the pictures on page 61, and I also found a good video describing the End Bound Single Bowline (EBSB) (https://www.youtube.com/watch?v=zeU8x7OmxoQ). However I'm having difficulties reproducing the other knots at page 77.

2) I practiced with both versions of "Scott's locked bowline" on top-rope at the gym (I haven't tried lead falling on them yet), and I'm very happy with them so far. Is there any particular reason to choose one version over the other? I understand that the simple bowline version #1034 1/2 (tail outside eye) is more resistant to ring loading than version #1010 (page 36); does this advantage carry over to the corresponding Scott's locked version? If not, is there any other significant difference?

3) Among the 5 inherently secured bowlines on page 77, which one would you ultimately recommend for tie-in and lead falling, and why?

4) With inherently secured bowlines, is there any disadvantage to tying an additional "double overhand stopper knot" with the leftover tail (like the figure on page 72) anyway? I understand that this is not necessary with inherently secure knots, but I found that it prevents the excess tail from flapping around and poking me while climbing ;-) Is there any good reason for me NOT to do it?

Thank you very much, and I'm looking forward to your replies and suggestions!
Take care
Davide

roo

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Re: Appropriate bowline knots for rock climbing
« Reply #1 on: September 01, 2020, 02:19:06 AM »
Hi everyone!

I have a few questions regarding the types of bowline knots that are appropriate for rock climbing. Until now I always used the traditional "retraced figure-8" knot to tie into my climbing harness. However, I recently started to practice repeated lead falls, and I decided to learn about bowlines because of their "jam-free" property. I found Mark Gommer's excellent paper: "Bowlines Analysis" version 2.9f (posted at http://www.paci.com.au/knots.php), and I read it carefully. There is a lot of great information in Mark's paper! Here are my questions:

1) Is there a document that shows the step-by-step process to tie all the inherently secure knots shown at page 77? I managed to "reverse engineer" the process to tie the Scott's locked bowline (both versions: "tail inside eye" based on #1010, and "tail outside eye" based on #1034 1/2) from the pictures on page 61, and I also found a good video describing the End Bound Single Bowline (EBSB) (https://www.youtube.com/watch?v=zeU8x7OmxoQ). However I'm having difficulties reproducing the other knots at page 77.

2) I practiced with both versions of "Scott's locked bowline" on top-rope at the gym (I haven't tried lead falling on them yet), and I'm very happy with them so far. Is there any particular reason to choose one version over the other? I understand that the simple bowline version #1034 1/2 (tail outside eye) is more resistant to ring loading than version #1010 (page 36); does this advantage carry over to the corresponding Scott's locked version? If not, is there any other significant difference?

3) Among the 5 inherently secured bowlines on page 77, which one would you ultimately recommend for tie-in and lead falling, and why?

4) With inherently secured bowlines, is there any disadvantage to tying an additional "double overhand stopper knot" with the leftover tail (like the figure on page 72) anyway? I understand that this is not necessary with inherently secure knots, but I found that it prevents the excess tail from flapping around and poking me while climbing ;-) Is there any good reason for me NOT to do it?

Thank you very much, and I'm looking forward to your replies and suggestions!
Take care
Davide
If you're having issues deciphering certain knots, that should be a flag that they may be too complex.  Simpler knots are less likely to have execution problems when you're tired or visibility isn't great and are easier to test for vulnerabilites and problems.  It's also hard to verify that you have a the right knot if it looks like a plate of spaghetti when finished. ;D

A vulnerability that came to light with the Scott's Locked Bowline is shown here:
https://igkt.net/sm/index.php?topic=6781.msg44616#msg44616

For some options that avoid these issues,  I'll leave this link so I don't have to re-type the contents:
https://igkt.net/sm/index.php?topic=6781.msg44659#msg44659

Generally, it's concerning that that Scott's Locked Bowline can capsize if the free end is pulled or snagged with an unloaded loop without much difficulty.
« Last Edit: June 04, 2022, 09:00:44 PM by roo »
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Davide Fossati

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Re: Appropriate bowline knots for rock climbing
« Reply #2 on: September 01, 2020, 03:13:57 AM »
Thank you Roo for your reply. I read your post regarding Scott's linked bowline alleged vulnerability, and several people replied to you casting serious doubt regarding its reproducibility; however you didn't provide the information they requested, nor convincing evidence that what you described can realistically happen.

I would like to prevent this post for becoming an ideological battleground. Please can anyone else respond to my original questions?

Thank you
Davide

roo

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Re: Appropriate bowline knots for rock climbing
« Reply #3 on: September 01, 2020, 03:44:40 AM »
Thank you Roo for your reply. I read your post regarding Scott's linked bowline alleged vulnerability, and several people replied to you casting serious doubt regarding its reproducibility; however you didn't provide the information they requested, nor convincing evidence that what you described can realistically happen.

I would like to prevent this post for becoming an ideological battleground. Please can anyone else respond to my original questions?

Thank you
Davide

Discussing and showing video of the likely cause of a safety incident involving a knot doesn't qualify as anything "ideological" in my opinion. 
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SS369

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Re: Appropriate bowline knots for rock climbing
« Reply #4 on: September 01, 2020, 03:47:53 AM »
Hi David.

I think you'll find that either of the simple locked bowlines are suitable and safe for your use. In my own experience, climbing, falling and various other usage, that the tail either in or out has not shown me any significant advantage over the other. That is my experience, but you should do some safe tests and determine what you feel is best, for you.

Both resist "ringloading" well.

With life critical knots, no matter which one chooses, it behooves those to become adept with the tying and inspection. After all it is up to you in the end.

Tying off the tail to eliminate the surplus is fine however you do it that works for you. The need is superfluous, in my opinion with regard to the "parent knot" ( the simple locked #1010 bowline).

My personal choice is my original offering.
I have been using it without failure for many years now and will continue to use it with confidence.
I recommend that you do what you feel you must to have confidence in Any knot you trust your life or safety with.

No sales or ideology here.

SS

agent_smith

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Re: Appropriate bowline knots for rock climbing
« Reply #5 on: September 01, 2020, 07:23:23 AM »
Thanks for your questions Davide,

My answers are as follows:

Quote
1) Is there a document that shows the step-by-step process to tie all the inherently secure knots shown at page 77?
I'm working on it.
I will be uploading a knot tying study guide with high quality photos sometime in the next month or so.
In any case, these knots aren't too difficult to learn to tie.
Lees link Bowline is tied from a starting base called the 'Myrtle'. Once you have the 'Myrtle' its fairly straightforward.
Its also a variant of the 'Lee zep Bowline' (refer page 70).

Quote
2) I practiced with both versions of "Scott's locked bowline" on top-rope at the gym (I haven't tried lead falling on them yet), and I'm very happy with them so far. Is there any particular reason to choose one version over the other?
There are 4 variants of Scotts locked Bowline. In my mind, this is an elegantly simple and inherently secure 'Bowline'. I wish that I had thought of it before Scott :)
I personally like to use the variant based on #1034 1/2.
This variant is particularly resistant to radial cross-loading of the eye.
The simple #1010 Bowline is vulnerable to radial cross-loading of the eye.
Variants based on #1010 or #1034 1/2 are all secure, with the #1034 1/2 variant even more resistant to radial cross-loading of the eye.

Quote
3) Among the 5 inherently secured bowlines on page 77, which one would you ultimately recommend for tie-in and lead falling, and why?
Please do not take any offense to my response to this question (I'm simply giving you an open and candid opinion).
The question is similar to EN892 dynamic climbing ropes - that is, which one would you ultimately recommend?
There are lots of choices for tying-in to a climbing harness - just like there are lots of choices of dynamic climbing ropes.
There are no laws governing rock climbing - other than rules you must obey at an indoor climbing gym (because it is a 'workplace').
You can tie-in with any of the inherently secure Bowlines - they are all 'safe'.
It comes down to your level of competence and confidence.
I prefer to tie-in with one the inherently secure Bowlines rather than the default #1047 Figure 8 eye knot (because I weigh 100kg and after a series of falls - #1047 can be hard to untie).
As a general rule, the more complex pathway the tail takes - the more secure the Bowline.

Quote
4) With inherently secured bowlines, is there any disadvantage to tying an additional "double overhand stopper knot" with the leftover tail (like the figure on page 72) anyway? I understand that this is not necessary with inherently secure knots, but I found that it prevents the excess tail from flapping around and poking me while climbing ;-) Is there any good reason for me NOT to do it?
Adding a strangled double overhand knot (ie backup stopper knot) as a security device does nothing.
Best to learn to tie-in so that you always have between 100mm-200mm tail (not less than 100mm).
Add a 'backup stopper knot' increases the overall 'footprint' of your tie-in knot. In a tricky/desperate clip, you have to reach a bit further along the rope to clip in to a quick-draw. If using 'aid' while hanging on gear (or some would say 'shade') the stopper knot reduces the distance you can pull up and then reach the next hold.

Quote
I would like to prevent this post for becoming an ideological battleground.
and;
Quote
I read your post regarding Scott's linked bowline alleged vulnerability, and several people replied to you casting serious doubt regarding its reproducibility; however you didn't provide the information they requested, nor convincing evidence that what you described can realistically happen.

In the first instance, there are some very passionate knot tyers on this forum - and it is hard to decouple ideology from debate.
Everyone has an opinion. There are some who cling very strongly to traditional concepts (eg traditional views on the definition of a 'loop' a 'turn' and a 'bight', etc).
Some take offense at the slightest hint of a insult - and indeed, emotions take over and they typically retaliate or complain.
Its like politics - I think in the USA you have Donald Trump supporters and then you have those who support the other camp. Who's right and who's wrong? Probably history will decide.

In the second instance, in my professional opinion, there is no such vulnerability with Scotts locked Bowline.
The purported test is flawed on account of the following factors:
1. The tester did not use EN892 rope.
2. The tester used a knot specimen that was not cinched tightly.
3. The tester created an enlarge 'eye' for the test - when tying-in for rock climbing, the eye is nominally between 70mm-120mm in size (no one ties-in with an enlarged eye).
4. The tester relied on a 'snag' caught inside the 'eye' - with a corresponding longitudinal cross-load (ie opposing load at the tip of the eye is axially aligned with the SPart). This scenario is very remote in a real-world climbing activity. It is highly unlikely that a protrusion could snag a relatively small eye during a free-fall event or while being lowered. The climbers body would have to be in close proximity to rock face, and the eye of the tie-in knot would have to be enlarged (ie larger than normal) - both of which are improbable.
In a free-fall, the likelihood of a protrusion snagging a nominally tied 'Bowline' is remote (ie minusculely small).

In the highly unlikely event that a protrusion could snag the eye, the opposing force would be divided equally across both eye legs (not on a single eye leg). It appears that the tester directed his pulling efforts on the outgoing eye leg rather than at the 'tip' of the eye. By biasing load on the outgoing eye leg, along with low stretch EN1891 rope and a loose knot, it was possible for him to loosen the nipping loop and and draw rope through the core. Once he got it started, he overcame 'inertia' and friction.
As a thought experiment, if the tester pulled on the returning eye leg, no rope would flow through the core. This thought experiment suggests that the tester directed his pulling efforts on the outgoing eye leg.

NOTE:
To the best of my ability, I have provided a response that is free of ideology and language that could be misinterpreted as insulting.

Davide Fossati

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Re: Appropriate bowline knots for rock climbing
« Reply #6 on: September 01, 2020, 09:38:18 PM »
Thank you Scott and Mark for your detailed and thoughtful responses!

Davide

Davide Fossati

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Re: Appropriate bowline knots for rock climbing
« Reply #7 on: September 02, 2020, 02:36:09 AM »
I just went to the climbing gym, and practiced repeated lead falls with a Scott's locked bowline. That knot is awesome! It stayed perfectly put and tight the whole time, and when I lowered after repeated consecutive lead falls, it was so easy to untie it - no jamming at all! I love it! :-)

Davide

roo

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Re: Appropriate bowline knots for rock climbing
« Reply #8 on: September 02, 2020, 03:35:30 AM »
I just went to the climbing gym, and practiced repeated lead falls with a Scott's locked bowline. That knot is awesome! It stayed perfectly put and tight the whole time, and when I lowered after repeated consecutive lead falls, it was so easy to untie it - no jamming at all! I love it! :-)

Davide
There is a relative that cures the two main vulnerabilities and is about the same complexity as the EBSB, and is far more secure & shake resistant:

https://notableknotindex.webs.com/monsoonbowline.html

Be sure you do slack shaking tests of the knots you use in the material you are using.  Simple falls are easy for many knots.
« Last Edit: September 02, 2020, 03:21:21 PM by roo »
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SS369

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Re: Appropriate bowline knots for rock climbing
« Reply #9 on: September 02, 2020, 04:24:26 PM »
I just went to the climbing gym, and practiced repeated lead falls with a Scott's locked bowline. That knot is awesome! It stayed perfectly put and tight the whole time, and when I lowered after repeated consecutive lead falls, it was so easy to untie it - no jamming at all! I love it! :-)

Davide

 :)

agent_smith

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Re: Appropriate bowline knots for rock climbing
« Reply #10 on: September 03, 2020, 05:12:28 PM »
To Davide Fossati:
I'm pleased you like Scotts locked Bowline - it is indeed simple and effective.

per roo:
Quote
There is a relative that cures the two main vulnerabilities and is about the same complexity as the EBSB, and is far more secure & shake resistant
?
These alleged vulnerabilities do not actually exist in the context of rock climbing.

One of the alleged 'vulnerabilities' is purported to occur with bungy (ie elastic) cord.
There is not one rock climber on planet Earth that would tie-in with bungy cord.
Rock climbers tie-in with EN892 dynamic rope.

The second alleged 'vulnerability' is shown in a test video that is clearly showing experimental bias.
The tester has made 5 serious errors that invalidate the test result as follows:
1. The tester did not use EN892 dynamic rope
2. The tester did not tightly dress and cinch the specimen knot
3. The tester created an enlarged eye for test
4. The tester deliberately pulled on the outgoing eye leg (ie pulling effort was directed on one side of the eye - in a real-world fall, load is applied at the 'tip of the eye' - so that force is equally divided across both eye legs - the reason being to deliberately induce slippage of the nipping loop).
5. The tester did not use an experimental 'control'.

This video is an excellent example of how to design and execute a test that yields a false positive along with experimental bias.
I now point trainee climbing Guides and Instructors to this video for discussion and learning about poorly designed and implemented knot tests.

As for the comment re the 'EBSB' Bowline - this is manifestly wrong.
The EBSB Bowline is totally secure and stable.
This also means (by default) that it is totally resistant to slack shaking and cyclic loading events.

roo

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Re: Appropriate bowline knots for rock climbing
« Reply #11 on: September 03, 2020, 05:30:23 PM »
To Davide Fossati:
I'm pleased you like Scotts locked Bowline - it is indeed simple and effective.

per roo:
Quote
There is a relative that cures the two main vulnerabilities and is about the same complexity as the EBSB, and is far more secure & shake resistant
?
These alleged vulnerabilities do not actually exist in the context of rock climbing.

One of the alleged 'vulnerabilities' is purported to occur with bungy (ie elastic) cord.
There is not one rock climber on planet Earth that would tie-in with bungy cord.

No, the vulnerability occurred in nylon kernmantle of a suboptimal dressing with cyclical high loading.  It was shown in bungee only to allow for step-by-step photography of the capsizing event.
« Last Edit: September 03, 2020, 05:31:44 PM by roo »
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roo

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Re: Appropriate bowline knots for rock climbing
« Reply #12 on: September 03, 2020, 05:35:36 PM »

per roo:
Quote
There is a relative that cures the two main vulnerabilities and is about the same complexity as the EBSB, and is far more secure & shake resistant


As for the comment re the 'EBSB' Bowline - this is manifestly wrong.
The EBSB Bowline is totally secure and stable.
This also means (by default) that it is totally resistant to slack shaking and cyclic loading events.
Huh?  Every knot can eventually be shaken free.  There is no question that the EBSB is substantially less resistant to slack shaking than the Monsoon Bowline.  It's not even close.
« Last Edit: September 03, 2020, 05:36:15 PM by roo »
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Dan_Lehman

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Re: Appropriate bowline knots for rock climbing
« Reply #13 on: September 05, 2020, 12:02:52 AM »
Every knot can eventually be shaken free.
Where'd this assertion originate?  (Is it to be
taken like the "nothing's perfect" assertion?)
I'm pretty sure that several lifetimes (and maybe
that of the rope vs. the shaker!) could be consumed
with "welded" knots, e.g. --and who knows what goes
on in setting a knot.  IMO, the Locktight is pretty
unshakeable for loosening; and the Mirrored BWL
does amply well, also.  --for practical use, not
theoretical measures.  The former is, as it's name
suggests, "locked TIGHT"; the latter is designed
to be secure against coming untied while LOOSE
--then shaken or stirred.

Quote
There is no question that the EBSB is substantially
less resistant to slack shaking than the Monsoon Bowline.
It's not even close.

As for reasonably safe ways to tie in, much with
the BWLs but including other knots as well, I must
be into the 200 count range (much sound & fury).
But what the user communities want is some FEW
that are agreed & known/accepted,
not this knotter's (me) incessant fiddled more & more.


--dl*
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roo

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Re: Appropriate bowline knots for rock climbing
« Reply #14 on: September 05, 2020, 12:44:16 AM »
I'm pretty sure that several lifetimes (and maybe
that of the rope vs. the shaker!) could be consumed
with "welded" knots, e.g. --and who knows what goes
on in setting a knot. 
In this context, we are discussing knots that are intended to resist becoming "welded", especially in the context of resistance to shaking before any fall occurs.

In slack shaking tests with common life support rope (including the likes of Bluewater II), knots can be shaken apart in the span of minutes, not lifetimes.
« Last Edit: September 05, 2020, 12:46:09 AM by roo »
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