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Constriction Hitch - test request
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BodaciousB


Jun 21, 2008, 2:31 PM
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Constriction Hitch - test request
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A constriction hitch is literally a clove with a twist. It holds itself tight, and it tightens with a 2-1 advantage.

I was setting up a top rope the other day and i decided to use 3 anchor points instead of 2. I had my main two, up on the cliff edge as a self equalizing sliding X. The third anchor just had a single 20" strand of 1" tube webbing with a water knot. I could have easily adjusted it to be a 3 way self equalizer, but i was wondering if i just made that third one a constriction hitch(backed up with a double overhand or better) would have been a good option for tightening that third anchor up to the other two. Which would eliminate the need for excessive tail length adjustments in the water knot.

Does anyone know how the constriction hitch compares to other knots as far as strength? Can anyone test it if not? This knot is hard to find information on, but i use it every day at work for many different things!

Edit: after being up for 24 hours, Knot and not seem to mean the same thing! Also some info about the knot under a slightly different name http://en.wikipedia.org/wiki/Constrictor_knot


(This post was edited by BodaciousB on Jun 21, 2008, 4:01 PM)


stymingersfink


Jun 21, 2008, 7:44 PM
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Re: [BodaciousB] Constriction Hitch - test request [In reply to]
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BodaciousB wrote:
A constriction hitch is literally a clove with a twist. It holds itself tight, and it tightens with a 2-1 advantage.

I was setting up a top rope the other day and i decided to use 3 anchor points instead of 2. I had my main two, up on the cliff edge as a self equalizing sliding X. The third anchor just had a single 20" strand of 1" tube webbing with a water knot. I could have easily adjusted it to be a 3 way self equalizer, but i was wondering if i just made that third one a constriction hitch(backed up with a double overhand or better) would have been a good option for tightening that third anchor up to the other two. Which would eliminate the need for excessive tail length adjustments in the water knot.

Does anyone know how the constriction hitch compares to other knots as far as strength? Can anyone test it if not? This knot is hard to find information on, but i use it every day at work for many different things!

Edit: after being up for 24 hours, Knot and not seem to mean the same thing! Also some info about the knot under a slightly different name http://en.wikipedia.org/wiki/Constrictor_knot
clicky


adatesman


Jun 21, 2008, 8:09 PM
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coolcat83


Jun 21, 2008, 9:00 PM
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Re: [adatesman] Constriction Hitch - test request [In reply to]
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a constrictor knot can get so tight that you won't be able to get it off without some prying and maybe even cutting.


BodaciousB


Jun 21, 2008, 11:10 PM
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Re: [adatesman] Constriction Hitch - test request [In reply to]
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adatesman wrote:
Quick question though... What materials you have in mind? In your example it was a single strand of 1" webbing tied with a constrictor hitch around 2 strands of a runner? I'm not quite following how it could have been a single strand if it had a water knot in it (as that implies a loop). A pic would be great. And was it 9/16 nylon or skinny dyneema?

I'm pretty sure its nylon, just a 1" tubular webbing from my local climb shop Smile. Its a single 20"strand doubled up with a constrictor with an overhand backup in place of the water knot. This would work best with cord, the knot looks really funky tying it in flat webbing. In these pictures i have a 20 foot web, and even with out the overhand knot to secure the constriction hitch there is a decent amount of friction(using it with no backup is instant death btw! and i have never used this knot while climbing).

But the advantage is you can easily add an extra anchor point to a system, with out having to equalize the whole thing all over again, just pull the tails until its tight, and tie the over hand.

This knot is only hard to untie when you tie it around something, like a pipe. When you can just unweight the system, the knot will not be around anything and with easy access to all the strands connected to it, you can practically wave it around to untie it.

I normally use a self equalizing sliding X with 2 doubled up 20" pieces of webbing though 2 carabiners at the rope connection.(Yes i do, realize this could hold most light trucks/suvs in a factor 1 fall) But quickly adding a 3rd to the system didn't seem like a bad idea at the time.
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adatesman


Jun 22, 2008, 6:52 AM
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stymingersfink


Jun 22, 2008, 9:56 AM
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Re: [BodaciousB] Constriction Hitch - test request [In reply to]
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BodaciousB wrote:


I'm pretty sure its nylon, just a 1" tubular webbing from my local climb shop Smile. Its a single 20"strand doubled up with a constrictor with an overhand backup in place of the water knot. This would work best with cord, the knot looks really funky tying it in flat webbing. In these pictures i have a 20 foot web, and even with out the overhand knot to secure the constriction hitch there is a decent amount of friction(using it with no backup is instant death btw! and i have never used this knot while climbing).

But the advantage is you can easily add an extra anchor point to a system, with out having to equalize the whole thing all over again, just pull the tails until its tight, and tie the over hand.


This knot is only hard to untie when you tie it around something, like a pipe. When you can just unweight the system, the knot will not be around anything and with easy access to all the strands connected to it, you can practically wave it around to untie it.

I normally use a self equalizing sliding X with 2 doubled up 20" pieces of webbing though 2 carabiners at the rope connection.(Yes i do, realize this could hold most light trucks/suvs in a factor 1 fall) But quickly adding a 3rd to the system didn't seem like a bad idea at the time.

I think that the possibility exists that you're overly complicating your anchor system. K.I.S.S.?

I'm not sure if you're saying 20inches, or 20feet with your (20"), but it sounds to me as though a lack of confidence in an ability to assess an anchor for quality/safety might be leading you to compensate by overbuilding to the point of ridiculousness.



easily adding another anchor point to a system"without having to equalize the whole thing all over again" is (imho) rarely done. If I don't have the gear in to feel good about my anchor BEFORE i begin to lace it up, there's no point in lacing it up, is there?

Rarely do I equalize more than two pieces. If an anchor requires more than three pieces of gear by me, they generally get built as separately equalized mini-anchors as part of a system. Trying to equalize more than three pieces with a single piece of lacing just does not seem like a fun thing to undertake.



stymingersfink


Jun 22, 2008, 10:03 AM
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Re: [BodaciousB] Constriction Hitch - test request [In reply to]
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BodaciousB wrote:
I was setting up a top rope the other day and i decided to use 3 anchor points instead of 2. I had my main two, up on the cliff edge as a self equalizing sliding X. The third anchor just had a single 20" strand of 1" tube webbing with a water knot. I could have easily adjusted it to be a 3 way self equalizer, but i was wondering if i just made that third one a constriction hitch(backed up with a double overhand or better) would have been a good option for tightening that third anchor up to the other two. Which would eliminate the need for excessive tail length adjustments in the water knot.
perhaps a better solution may have been to utilize the third anchor point with it's own loop of webbing to the master point, then pulling the slack out of the loop with a bight off one strand, tying an O.H. or Fig 8 in it.

Quick, simple, removable when finished, proven extensively in the field. Why make things more complicated than necessary?


Partner angry


Jun 22, 2008, 10:15 AM
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Re: [stymingersfink] Constriction Hitch - test request [In reply to]
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The whole thing seems pointless to me.


BodaciousB


Jun 22, 2008, 12:24 PM
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Re: [adatesman] Constriction Hitch - test request [In reply to]
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adatesman wrote:
Gotcha.... a loop runner tied with the constrictor hitch rather than a water knot. Thanks for the pics. I'm curious how well that knot holds in webbing, and will definitely do some testing on it.


EDIT- fiddling with this over coffee a bit... Its a bit hard to see in the pics, but it looks like the webbing makes 2 passes around? As in take a 48" runner, twist and fold it into a 24" runner that there are 2 passes of material around? That's the only way I could figure to tie it....

I couldn't get it to hold at all like that in 4mm cord (or is it 5mm?), but it did hold in webbing ok by friction (just pulling by hand). Kinda disturbing what it does under cyclical loading though... the knot just creeps apart. Could be solved with a pair of half hitches, but then you lose the ease of adjustablity.

How about this instead... tie your long runner as normal with a water knot, clip it to your anchor and then tie it to the biner on your additional point with a clove using the bight (both strands of the loop) rather than a single strand. Dead simple to adjust, easy to undo, strong and doesn't require any fancy knotwork. To back it up either clip a biner through the loop tail coming out of the knot and then around the working end of the webbing or maybe a half hitch or two.

Yeah its two passes around and it will not hold with no backup knot. an dany knot will work you just need it to pull then ends toward each other to lock the constrictor into place. This knot will work in any cord of any size.

I do like your clove idea too. Its better than trying to adjust the water knot.


BodaciousB


Jun 22, 2008, 12:41 PM
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Re: [stymingersfink] Constriction Hitch - test request [In reply to]
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stymingersfink wrote:
Rarely do I equalize more than two pieces. If an anchor requires more than three pieces of gear by me, they generally get built as separately equalized mini-anchors as part of a system. Trying to equalize more than three pieces with a single piece of lacing just does not seem like a fun thing to undertake.

Actually it sounds like we build anchors the same way, i just use more webbing(20feet x 2 strands, sometimes 3. I also build 2 as an equalized system. This one time i wanted to use three simply because i could. i just wanted practice. I also wanted it to be add the "separately equalized mini-anchors as part of a system." However i wanted to shortcut the equalization with a constrictor.


stymingersfink


Jun 22, 2008, 1:23 PM
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Re: [BodaciousB] Constriction Hitch - test request [In reply to]
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BodaciousB wrote:
stymingersfink wrote:
Rarely do I equalize more than two pieces. If an anchor requires more than three pieces of gear by me, they generally get built as separately equalized mini-anchors as part of a system. Trying to equalize more than three pieces with a single piece of lacing just does not seem like a fun thing to undertake.

Actually it sounds like we build anchors the same way, i just use more webbing(20feet x 2 strands, sometimes 3. I also build 2 as an equalized system. This one time i wanted to use three simply because i could. i just wanted practice. I also wanted it to be add the "separately equalized mini-anchors as part of a system." However i wanted to shortcut the equalization with a constrictor.
"Shortcuts" often result in disaster.


knudenoggin


Jun 23, 2008, 4:14 PM
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Re: [BodaciousB] Constriction Hitch - test request [In reply to]
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Putting aside the question of actually making an equalized 3-point anchor,
I have a good idea of what a Constrictor knot (a binder, not hitch, btw) is;
and I can make no sense of the OP!?!?

In reply to:
a loop runner tied with the constrictor hitch rather than a water knot

Huh? A Water knot is a knot that joins two ends; a hitch, or binder, is
NOT--they secure material to an object.

The form of the Constrictor has been known in some climbing circles for
a long time as a sling shortener (the Constrictor--also Dbl.C.--can be tied
in the bight (no ends)); but I don't see that as figuring in the OP.

Crazy


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