Author Topic: Karash rescue harness and waist loop  (Read 8918 times)

Dennis Pence

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Re: Karash rescue harness and waist loop
« Reply #15 on: May 08, 2023, 10:17:59 PM »
I just realised that the waist/chest loop is no other than the Portugese BL (#1072) - as Greg suggested, but didn't get it...

p.s. It looks like the Wikipedia entry for the Portugese bowline has it all wrong...

Yes, the Wipedia entry for "Portuguese Bowline" is pretty terrible.  I wish I knew how to contribute to Wikipedia to help fix it.  The main entry (to the right on the first page) has a Cowboy Bowline finish and the tying instructions give a weird Portuguese Bowline with Splayed Loops (see ABoK #1073 for a more natural way to get the splayed loops).  In one of Ashley's descriptions of the Portuguese Bowline [ABoK #1848], he references a Riesenberg book where it is called a French Bowline.  If you look up that reference (you can find it on Google), you find tying instructions there where when you start to form the second loop, you pass the free end through the nipping loop.  Ashley either passes this free end above the nipping loop [#1848] or lays it on top of the nipping loop [#1072].   It took me awhile to realize that you can move this part after you complete the knot but before you tighten from any of these three positions to any other.  However, if you add any of the many "locking mechanisms" for a Bowline to this Portuguese Bowline, you may "lock" the part between the two loops in a particular postion where it then cannot move to the other positions.  Still there is a tradition in knot-tying books to call it a French Bowline if this part between the two loops is placed through the nipping loop and to call it a Portuguese Bowline if this part between the two loops is placed either above or on top of the nipping loop.  You can also get a splayed loop version using any of the three positions (but you may not be able to move to the other positions).

The point I was making about the upper part of the Karash harness was that the structure locally looks like that of a Portugues Bowline (with the part between the two loops replaced by the lead coming from below which is placed either above or on top of the nipping loop).

mcjtom

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Re: Karash rescue harness and waist loop
« Reply #16 on: May 09, 2023, 04:15:58 AM »
Quote
Ashley either passes this free end above the nipping loop [#1848] or lays it on top of the nipping loop [#1072].

I'm not sure if I'm seeing it right, but those two seem identical, just rotated 180 deg?  The way I remember where the strand for the second loop goes is to place it between (underneath) both strands of the final tail U-turn and the S-Part.

p.s. This video uses the French? variant (with the second loop strand going through the choking loop) to form a nifty clip/soft shackle at the end of the line, locked by a long tail.

https://youtu.be/c0xYfObWrsg
« Last Edit: May 09, 2023, 05:28:16 AM by mcjtom »

mcjtom

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Re: Karash rescue harness and waist loop
« Reply #17 on: May 09, 2023, 06:44:02 AM »
Just wanted to add that Scott's lock seems to work ok for the Portugese BL.

Dennis Pence

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Re: Karash rescue harness and waist loop
« Reply #18 on: May 11, 2023, 05:02:51 PM »
Here I try to show the three positions (mostly as you tie them, because they might even move when you tighten).  After the knot is tightened, you can hardly tell the difference.

There can be more than two loops as well.  The Bowline-on-a-Coil is an extreme example of a Portuguese Bowline where the coil is placed usually above the nipping loop.

You can do virtually all of the enhancements to an ordinary Bowline that Mark Gommers has in his Bowline Analysis paper to a Portuguese Bowline.  I do not think there is any need for such enhancements for the Karash rescue harness set up because the person being rescued is usually immediately hauled up.  The Bowline has a problem in climbing and rescue ropes when it is not going to be under tension and might work loose before it is needed in a fall.
« Last Edit: May 11, 2023, 05:34:22 PM by Dennis Pence »

Kost_Greg

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Re: Karash rescue harness and waist loop
« Reply #19 on: May 12, 2023, 10:42:33 PM »
In the video (1:40') it says the Karash double loop is supposed to be 'better' than double loop bowline on a bight because there is no 'crossing lines'.  What does it mean?

If you start the tying proccess from a well dressed overhand loopknot, you'll probably get a perfect bowline on a bight with no crossing lines (i think Karash is starting from a well dressed figure eight too).

When it comes to life critical applications, one should check the property of redundancy of a double eyeknot, which means that if one of the eyes fails, there has to be the other one as a back up.

if the secondary eye fails (secondary eye=direct continuation of the tail), we would still have the primary bowline eye.

However, if the primary eye (primary eye=direct continuation of the SPart) fails, things might get tricky, one has to check if the remaining secondary bend eye, is strong enough to hold efficiently without failure.

So, in answering this question "which is better", one has to take into consideration, which one of the two has the strongest secondary bend loop, with the hypothesis that both primary eyes of karash double loop, bowline on a bight, would induce failure.
« Last Edit: May 12, 2023, 10:51:10 PM by Kost_Greg »
Going knots

Dennis Pence

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Re: Karash rescue harness and waist loop
« Reply #20 on: May 13, 2023, 12:03:19 AM »
I just looked at the Wikipedia entry for "French Bowline."  It is really just a Bowline-on-a-Coil using the "snap", "rapid", "boy's", or "slip-knot" method.  Karash also uses  what he calls the "rapid" method for tying his waist Bowline wrap.  I disagree with Wikipedia, and still think that "French" should be associated with running the part between the two loops through the nipping loop.