Author Topic: Simple lock for the bowline  (Read 127175 times)

xarax

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Re: Simple lock for the bowline
« Reply #105 on: October 21, 2011, 07:52:44 PM »
   Another end-of-line loop that works pretty well in "proper" ring loading circumstances - where both eye legs are tensioned, while the standing end is not. ( See the attached pictures ). In this configuration, Rusty s bend (a very simple and compact bend (1) ), looks like a crossing knot-based loop knot, with a symmetric inter-"locked" link tied at the end of the eye leg of the bight.
 
1) http://igkt.net/sm/index.php?topic=2694.0
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Dan_Lehman

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Re: Simple lock for the bowline
« Reply #106 on: October 22, 2011, 06:56:13 AM »
rock-climbers are who introduced... and defined the term, for any eye knot--, not particular to a bowline
... The generalization of the use of ["ring-loading"] in the case of the bowline*, is simply wrong. The bowline* - and all the bowline*-like loops that are based on a TIB nipping structure to hold and secure the tail - 
...works because its nipping loop is tensioned, and its nipping loop is tensioned [] iff- and because - the standing end and the eye leg of the standing part are both tensioned.

  So, a "proper" ring loading circumstance - where the standing end is not loaded at all - makes sense to many eye knots, indeed most of them...but not to the bowline*.                                     
  I might even dare to DEFINE the bowline*, as an end-of-line loop that is automatically released and completely untied,  if and when the bight is tensioned, while the standing end is not.

Whew, you do spew!

Look, the term refers to a loading of a *knot*
--regardless of what transpires from the loading,
In fact, as you can readily see, the common bowline
can have satisfactory or catastrophic behavior --YMMV.
The so-called "cowboy bowline" should avoid the latter,
and is a Lapp bend (reverse sheet bend on ring-loading
--and is surely a *bowline* even w/a "proper collar"!


Hey, on that "dbl.harness loop", take the tail under itself
and tucked out the turNip --that looks pretty good (for
resisting loosening-when-untensioned) !


--dl*
====

xarax

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Re: Simple lock for the bowline
« Reply #107 on: October 22, 2011, 03:16:57 PM »
   The so-called "cowboy bowline" should avoid the latter,
and is a Lapp bend (reverse sheet bend on ring-loading

   ( I have used the term "common bowline" - or "bowline* -  for both loops, the "left-" and the "right-" hand bowline - in contradiction to the "Eskimo bowline" . )
   In the case of the common bowline, I do not believe that the "reverse Sheet bend",- indeed any  bend where the one link is a loose nipping loop - can hold, when the standing end is not loaded at all. On the contrary, in the case of the "Eskimo bowline" and a "proper" ring-loading condition, the normal Sheet bend will hold. The difference you mention, between the two forms of common bowline, does not exist under those extreme circumstances you have described, because in that case both loops will not hold ! Would you trust a "reverse Sheet bend" that is the only thing left there, after a gradual untensionong of the standing end and loosening of the nipping loop? It will not be a Lapp bend you have tied and tighten, it will be a Lapp bend that should have been tied and tighten by itself...or else, a Lapp bend that you should have prayed  to be self-tied, self-tighten and holding - if that would be of any help... Noope, if by "ring loading" we mean a completely loose standing end, we should not trust any form of the common bowline - and we should use a secure Eskimo bowline instead. ( In general, I use an Eskimo bowline when I anticipate that the angle between the eye legs would become greater than 120 degrees).( See the attached pictures for a secure Eskimo bowline).
   Try the Rusty s loop : I believe it is a very nice, compact and quite secure loop, that is not known and used as much as it should. I do not like very much it as a bend ( two loaded limbs )- because I think it is a little unstable, - but as a loop ( three loaded limbs ), it is much better. You may also try your Sidewinder bend, in its untucked variation (1). Any similar elongated bend, where both tails leave the knot s nub from its middle, can form a loop suitable for "proper" ring loading ( where one of those tails takes the place of the standing end of the loop).

1) http://igkt.net/sm/index.php?topic=2694.msg17078#msg17078
« Last Edit: October 22, 2011, 04:35:45 PM by xarax »
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roo

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Re: Simple lock for the bowline
« Reply #108 on: March 01, 2012, 07:19:27 PM »
Looking over the site and trying out links found I see that the www.iland.net/~jbritton/bowline.htm link is dead.

That said, I want to offer an easy method of securing the WE of a "standard" bowline (instead of starting a new thread.
It appears to help with some anti-ring loading and most certainly inhibits shaking loose.

Adds a tad of bulk, but then so do other methods and the WE is pointed away from the loop, if that is a major concern.
I've not found reference to this simple method, as of yet.

Thoughts?

SS
Sorry for the tardy reply, but I didn't want to divorce this comment from the thread by starting a new topic.

I like many of the features of this backup, which in many ways is more secure than many common bowline backups.

On the other hand, this shifty (for lack of a better term) structure allows a number of different dressings.  At least one dressing/form allowed the initial bowline coil to straighten out under a higher strain test which allowed the loop to suddenly shrink.
« Last Edit: March 01, 2012, 07:53:03 PM by roo »
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SS369

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Re: Simple lock for the bowline
« Reply #109 on: March 01, 2012, 09:25:28 PM »
Looking over the site and trying out links found I see that the www.iland.net/~jbritton/bowline.htm link is dead.

That said, I want to offer an easy method of securing the WE of a "standard" bowline (instead of starting a new thread.
It appears to help with some anti-ring loading and most certainly inhibits shaking loose.

Adds a tad of bulk, but then so do other methods and the WE is pointed away from the loop, if that is a major concern.
I've not found reference to this simple method, as of yet.

Thoughts?

SS
Sorry for the tardy reply, but I didn't want to divorce this comment from the thread by starting a new topic.

I like many of the features of this backup, which in many ways is more secure than many common bowline backups.

On the other hand, this shifty (for lack of a better term) structure allows a number of different dressings.  At least one dressing/form allowed the initial bowline coil to straighten out under a higher strain test which allowed the loop to suddenly shrink.

Tardy replies are welcome too roo.
Please explain your first sentence about "divorcing this comment, etc..."

I am glad you found the many features to your liking. What are they please?

This shifty-ness you allude to, can you be more specific? Because there was a picture of this method that I just can't see any confusion that could lead to what you've stated

Can you include a diagram/picture of some kind that shows the dressing/form that gave you the stated results.

When I tie this, I tie a standard bowline just loose enough to reeve in the working end, add the method of securing the tail, grab the central "knot" and pull each leg individually, the tail last.

I have used this secured bowline as a harness tie in (survived "test" falls of six feet a number of times on dynamic ropes), two of these secured bowlines to tow a tractor out of a ditch (using a 3/4" bull rope). 

If the knot is tightened, as most knots should be before use, it should not fail. I have yet to fail it in any way. Using my own weight and strength, pulling, jumping, bouncing, with the loop narrow and widely spread, tugging hard on individual legs of the loop and as a whole, not only did it not capsize and not deform it was able to be untied by hands alone.

I look forward to what your other hand has to say. ;-)

SS

roo

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Re: Simple lock for the bowline
« Reply #110 on: March 01, 2012, 09:38:41 PM »
Tardy replies are welcome too roo.
Please explain your first sentence about "divorcing this comment, etc..."
I just believe it's relevant to this thread, and doesn't warrant a new topic.

Quote
I am glad you found the many features to your liking. What are they please?
Simplicity and security.

Quote
This shifty-ness you allude to, can you be more specific?
Sure.  Depending on how hard I pull the different parts of rope after tying, I can get it to assume different forms; sometimes radically different.

Unfortunately, the neatest form, the very one you have pictured with the free end making a straight line exit, is, I believe, the form that had the sudden shrink problem.  I think this tendency may be lessened if you force the free end to take a curvier, more serpentine exit from the knot while maintaining the underlying bowline structure.
« Last Edit: March 01, 2012, 10:16:01 PM by roo »
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roo

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Re: Simple lock for the bowline
« Reply #111 on: March 02, 2012, 02:43:16 AM »
Unfortunately, the neatest form, the very one you have pictured with the free end making a straight line exit, is, I believe, the form that had the sudden shrink problem.  I think this tendency may be lessened if you force the free end to take a curvier, more serpentine exit from the knot while maintaining the underlying bowline structure.
I'd like to update my findings after further testing.  I was doing more pulls in 3/16" nylon braid, and while I was getting capsized forms that were sometimes hard to untie, I wasn't getting the same sudden strinking problem I was getting earlier, until I gave the free end a firmer tug, which caused the "U"-shaped portion of the underlying bowline to flatten some and fall back a little.  That form did give me the sudden shrink issue and a bit of a challenge to untie.

So I think my earlier recommendation would still be good, but perhaps more importantly,  I'd add that you want to make sure that the "U" doesn't flatten or fall back.  Also this issue may not arise at all under lower to moderate strains.
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SS369

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Re: Simple lock for the bowline
« Reply #112 on: March 02, 2012, 10:07:53 PM »
Just photographed a small quick test sample of this security modification.
I used 5/16 inch double braided polyester/nylon arborist rope (approx.tensile strength 4000lbs. new).

Tied the bowline with added modification, pulled each leg individually, the tail last, while holding the knot body till all space was removed and repeated the the pulls again.

Just so I know I have said it, the knot modification I presented earlier in this thread was of the loose knot, for clarity sake.

I loaded the loop with approximately 500 lbs. I added my own body weight and bounced "shocking" the knot.

I also tested the ability to resist ring loading by applying the same weight (no bouncing this time).

Here are some photos of the still tightened loop knot.

Please indicate on my photos where your testing is giving failure(s)

SS

roo

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Re: Simple lock for the bowline
« Reply #113 on: March 02, 2012, 10:31:40 PM »
Please indicate on my photos where your testing is giving failure(s)
Your pictures show a better dressing with the serpentine free end and a mostly non-flattened collar that should be good.  But I've attached an image to show my guess as to what is transpiring at the moment of capsizing in a suboptimal dressing.

The red arrow indicates how a straighter free end would deform the bowline coil before loading.

The yellow arrow is my guess as to the primary capsizing event that starts the ball rolling, by sliding back and down.  It happens too quickly for me to see firsthand.
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SS369

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Re: Simple lock for the bowline
« Reply #114 on: March 02, 2012, 10:42:49 PM »
When you've tied this, is this the configuration of the dressed knot (as shown in the most recent photos)? Or are you leaving the knot loose like my first presentation photo?



roo

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Re: Simple lock for the bowline
« Reply #115 on: March 02, 2012, 10:49:49 PM »
When you've tied this, is this the configuration of the dressed knot (as shown in the most recent photos)? Or are you leaving the knot loose like my first presentation photo?
While the dressing isn't loose, or at least not as loose as shown in the "presentation" photo, the collar is lower and flatter, which would allow for the slide.  And this lower and flatter collar was caused by a harder tug on the free end (working end), which also left a straighter, non-serpentine free end, and the aforementioned deformed initial bowline coil.

Smaller, stretchier nylon rope is likely the easiest mode of seeing the effects under human power.
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SS369

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Re: Simple lock for the bowline
« Reply #116 on: March 02, 2012, 11:17:35 PM »
Please try it with your cord/rope, tightened as I have mentioned by pulling the individual loop legs, SP and tail last. Repeat this and give it your best shot.

I have tried this loop knot with basically every type of cord and rope I have, from 3/4" very stiff, old (Bull) rope, many relatively brand new BlueWater ropes 9mm -11mm static and dynamic, BW Titan 5.5mm Dyneema, 3/8" twisted nylon, 1/2" hemp/manila(?), 1/2" braided nylon, 6mm accessory cord, 3/16" starter pull cord, paracord, insulated wire, venetian blind cord 1.4mm, 1/16" aircraft cable and some of the cheapo box store cords.
I thought about trying it with the 1 1/4" climbing rope, but you have to stop somewhere.

I can not fail it by hand or by my "test rig" which is a ratcheting come-along and V-8 engine. Suitable rope of course. ;-)

I will say that tied using 1/8" braided nylon and some of the soft-ish, non stiff cord and the very small stuff it is a bear to untie after body weight and strength is applied, but doable. Yes with needle nose pliers. ;-)

roo

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Re: Simple lock for the bowline
« Reply #117 on: March 02, 2012, 11:36:55 PM »
Please try it with your cord/rope, tightened as I have mentioned by pulling the individual loop legs, SP and tail last. Repeat this and give it your best shot.
Why would I do this again?  We agree here, as I have mentioned many times, that a good dressing is unlikely to have problems

I'm merely bringing up a suboptimal dressing and pre-loading knot deformation that occurs when one gets overzealous with pulling the free end (as I did on accident a few days ago).

Quote
I have tried this loop knot with basically every type of cord and rope I have, from 3/4" very stiff, old (Bull) rope, many relatively brand new BlueWater ropes 9mm -11mm static and dynamic, BW Titan 5.5mm Dyneema, 3/8" twisted nylon, 1/2" hemp/manila(?), 1/2" braided nylon, 6mm accessory cord, 3/16" starter pull cord, paracord, insulated wire, venetian blind cord 1.4mm, 1/16" aircraft cable and some of the cheapo box store cords.
I thought about trying it with the 1 1/4" climbing rope, but you have to stop somewhere.
It's strange to be testing the larger ropes when I specifically described (and encouraged the use of) the small 3/16", stretchy nylon that I was using, and, equally important, the suboptimal dressing in question. 

It's not very feasible (and a little hazardous) to introduce higher strain in larger rope diameters.  It's also harder to get a good feel of what is going on in terms of how close you are to rupture.

update, ref:
http://igkt.net/sm/index.php?topic=4480.msg32318#msg32318
« Last Edit: June 18, 2014, 08:53:53 PM by roo »
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SS369

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Re: Simple lock for the bowline
« Reply #118 on: March 03, 2012, 12:15:50 AM »
Please try it with your cord/rope, tightened as I have mentioned by pulling the individual loop legs, SP and tail last. Repeat this and give it your best shot.
Why would I do this again?  We agree here, as I have mentioned many times, that a good dressing is unlikely to have problems

I'm merely bringing up a suboptimal dressing and pre-loading knot deformation that occurs when one gets overzealous with pulling the free end (as I did on accident a few days ago).

Quote
I have tried this loop knot with basically every type of cord and rope I have, from 3/4" very stiff, old (Bull) rope, many relatively brand new BlueWater ropes 9mm -11mm static and dynamic, BW Titan 5.5mm Dyneema, 3/8" twisted nylon, 1/2" hemp/manila(?), 1/2" braided nylon, 6mm accessory cord, 3/16" starter pull cord, paracord, insulated wire, venetian blind cord 1.4mm, 1/16" aircraft cable and some of the cheapo box store cords.
I thought about trying it with the 1 1/4" climbing rope, but you have to stop somewhere.
It's strange to be testing the larger ropes when I specifically described (and encouraged the use of) the small 3/16", stretchy nylon that I was using, and, equally important, the suboptimal dressing in question. 

It's not very feasible (and a little hazardous) to introduce higher strain in larger rope diameters.  It's also harder to get a good feel of what is going on in terms of how close you are to rupture.

I must have read you wrongly then, don't bother with retesting then.

Suboptimal dressing can be a challenge with many knots and hopefully that is something understood by the members (I believe) and the ones to come (eventually).

Since I did my testing with larger diameter cords and ropes, and the smaller various as well, long before these most recent posts with you, I added the selection I have tried it with.
For others to read too.

Sometimes the size and material of what one ties a knot with can influence an effect such as jamming, slippage and not holding well at all, even with "normal" loads.

Testing to some degree using larger ropes makes sense. Perhaps not to extremes, but at least to see how the knot performs, whether it will close down and lock, deform or whatever. I think that the person who decides to try this knot modification out should use the type/size rope that they will most likely use this knot with.

And if someone has the desire and the wherewithal to safely test, as I did, then by all means they should.

Edit: BTW, I took the very same rope just now (the most recent photos), tied the knot loosely as in the original presentation and pulled it using the come along. It did not fail.
« Last Edit: March 03, 2012, 12:26:37 AM by SS369 »

xarax

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Re: Simple lock for the bowline
« Reply #119 on: March 03, 2012, 11:06:41 AM »
Testing to some degree using larger ropes makes sense. Perhaps not to extremes, but at least to see how the knot performs, whether it will close down and lock, deform or whatever.

   I always prefer larger ropes, because only there I can SEE what is happening !  :)
   However, I disagree with the light loading. Why not load the rope "to the extremes"? Even if you are not going to put this rope under such high a loading ever, you will put smaller diameter ropes under loads that are extreme for their size, at the limits of their ultimum strength. Presumably, the situations are similar, so it pays to have an idea, to get a glimpse of what is happening when the rope is deforming under high load, and near the rupture point. I do not understand why people are afraid of doing destructive tests...Just keep your body material at a safe distance !  :)
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