Cow's Tails Center Attachment

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Cow's Tails Center Attachment

Postby cavedoc » Apr 15, 2011 12:15 am

In another thread,
NZcaver wrote:The center knot in my double cowstail is an overhand bight, as recommended by Alpine Caving Techniques.


which I have done as well because it's highly functional and takes up very little space in a rather congested part of my vertical system. More recently I've gone to a figure-8 to have a bit more compression available should I take a fall on it. And I do retie it from time to time.

Merchant in Life-on-a-Line recommends using TWO figure-8s in the center to make each side of the cowstail independent, avoid atypical loading if you have a load attached to a leg of the cowtail while climbing, and create an extra loop that might come in handy...for something. Anyone on this side of the pond do it that way? Any other choices out there someone wants to defend?
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Re: Cow's Tails Center Attachment

Postby NZcaver » Apr 15, 2011 12:31 am

Using a pair figure eights in the middle seems unnecessarily bulky/awkward to me, and a waste of rope. But I guess some people like it.

Of course a butterfly knot is rather popular among US cavers, but I prefer to keep things little more compact. Sewn terminations would be even more compact, but I don't have a machine that will do that right now.
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Re: Cow's Tails Center Attachment

Postby cavedoc » Apr 15, 2011 12:44 am

NZcaver wrote:Sewn terminations would be even more compact, but I don't have a machine that will do that right now.


No doubt. But they would generate the highest shocks if ever loaded in a fall. Sewn would not be my first choice, or second, or third. But lots of people seem to buy sewn webbing for this.
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Re: Cow's Tails Center Attachment

Postby self-deleted_user » Apr 15, 2011 1:32 am

I have a butterfly in the center of mine.
Self-deleted due to large troll population on the forum, and absence of moderation.
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Re: Cow's Tails Center Attachment

Postby NZcaver » Apr 15, 2011 2:13 am

cavedoc wrote:
NZcaver wrote:Sewn terminations would be even more compact, but I don't have a machine that will do that right now.


No doubt. But they would generate the highest shocks if ever loaded in a fall. Sewn would not be my first choice, or second, or third. But lots of people seem to buy sewn webbing for this.

Very true. Or another option...

Image

(Although admittedly the Petzl Zyper "V" is a little too long for a caving cowstail.)
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Re: Cow's Tails Center Attachment

Postby Carl Amundson » Apr 15, 2011 8:51 am

I use a figure 9 as the central knot for my cows tail.
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Re: Cow's Tails Center Attachment

Postby Kendalcaver » Apr 22, 2011 3:05 pm

cavedoc said:
More recently I've gone to a figure-8 to have a bit more compression available should I take a fall on it.


Fair enough, but in practice, if you took a fall would it really impact directly on the knot, or would you tend to sort of slither down the walls with a somewhat attenuated fall – a theoretical 1:1 FF perhaps, but in practice far less challenging to the rope/harness/belay set up?

In other words, is a simple overhand knot adequate?
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Re: Cow's Tails Center Attachment

Postby cavedoc » Apr 22, 2011 3:41 pm

Kendalcaver wrote:In other words, is a simple overhand knot adequate?


Probably. The danger would be if attached to a solid anchor like a bolt. Of course the first thing is to never get above your attachment point with a cowstail. I suspect you're right about the "slithering" aspect for most such falls. But if the 8 doesn't interfere in any way, and since testing suggests better shock absorption with a recently tied 8, then why not? My impression is that the 8 on my system does not get in the way despite its mildly increased bulk over the overhand. So that's why I do it. I would not condemn in any way those who chose the overhand.
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Re: Cow's Tails Center Attachment

Postby NZcaver » Apr 22, 2011 5:21 pm

cavedoc wrote:
Kendalcaver wrote:In other words, is a simple overhand knot adequate?


Probably. The danger would be if attached to a solid anchor like a bolt. Of course the first thing is to never get above your attachment point with a cowstail. I suspect you're right about the "slithering" aspect for most such falls. But if the 8 doesn't interfere in any way, and since testing suggests better shock absorption with a recently tied 8, then why not? My impression is that the 8 on my system does not get in the way despite its mildly increased bulk over the overhand. So that's why I do it. I would not condemn in any way those who chose the overhand.

Good answer. Incidentally, this subject has also been discussed in several previous topics, e.g. overhand knot suitable for cowstails?
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Re: Cow's Tails Center Attachment

Postby PeterFJohnson » Apr 22, 2011 6:01 pm

w/r/t sewn terminations both Sterling and Petzl(as well as others I am sure) make premade sewn termination lanyards out of dynamic rope. The only downside is the only ones I am aware of are around 10.5-11 mm. I imagine that diameter is a bit large for many people. I never seem to see them mentioned in these discussions.

Personally, I will stick with my low bulk spelegyca and keep my attachment point above me.
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Re: Cow's Tails Center Attachment

Postby TAG caver » Jun 26, 2011 3:35 pm

Im considering using tachyon eye splices to terminate my cowstails next time I replace them. Properly constructed splices are stronger than knots and certainly have a lower profile. Lower profile is my main incentive as space on my omni is limited. As for shock absorption I use dynamic to make my tails and I really dont see how its possible using proper SRT to generate enough of a fall factor to worry about it. Anyone else played around with this? Is this a bad idea?
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Re: Cow's Tails Center Attachment

Postby chh » Jun 26, 2011 4:59 pm

TAG caver wrote:Im considering using tachyon eye splices to terminate my cowstails next time I replace them. Properly constructed splices are stronger than knots and certainly have a lower profile. Lower profile is my main incentive as space on my omni is limited. As for shock absorption I use dynamic to make my tails and I really dont see how its possible using proper SRT to generate enough of a fall factor to worry about it. Anyone else played around with this? Is this a bad idea?


I have used double braid ropes to make cowstails. I still used a knot on the D-ring attachment, but put spliced eyes in each of the carabiner terminations.
I've thought about splicing eye-to-eyes for cows tails. i.e. a straight piece of rope with an eye splice on either side. This would have all the benefits of seperate cowstails, dynamic rope, and a low bulk attachment. The problem is that it's very finicky to splice eye-to-eyes with such a short piece of working rope in between the eyes. That and I broke my splicing wand. And, as you taper your splices you are, I believe, negating some of the dynamic properties of the rope. This is especially pertinent in the short cowstail when the ends of your tapers essentially meet in between the eyes.
I've also only ever spliced well used rope into cowstails, which is a lot more difficult than splicing new double braid rope. A trick I've discovered here is to splice one end and then pull some extra cover from the rest of the rope and then make the cuts for the other eye. This gives you more cover to work with and makes the cover easier to bury than in a used rope when cover has already been milked all the way out.
This might make some sense to you if you've done some double braid splicing before, otherwise it's probably nonsense, for which I apologize. And I'm probably not doing a great job of explaining it even if you have a little splicing experience.
I also haven't figure out a good way to splice and eye in the middle of a line and then eyes in the terminations of the cowstail as well. You could use a locking brummel, but I think that would be even MORE finiky than doing 2 seperate eye-to-eye splices for your cowstails.
Take that FWIW I guess...
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Re: Cow's Tails Center Attachment

Postby Caver John » Oct 19, 2011 9:55 am

I use a clove hitch at the center attatchment. I realize it offers very little if any shock absorption but It takes up no space and i can easily adjust it evry time I climb. I dOnt like leaving weighted knots always tied.
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Re: Cow's Tails Center Attachment

Postby Jeff Bartlett » Nov 1, 2011 2:02 pm

Sungura wrote:I have a butterfly in the center of mine.


Are you attempting to contribute to the conversation, to defend this particular choice, or are you just telling us about what you do in order to fill space? Seems like the latter.

If we're just filling space here, I'd like everyone to know that I enjoy long walks on underground beaches, my favorite kind of ice cream is mint chocolate chip, and I don't think Kim Kardashian is attractive at all. Wait, what's that? That's NOT what we're supposed to be doing here? Oh, sorry. Let me hop back on-topic, then:



I use a figure 8 on a bight at the midpoint of my cow's tails. I end up replacing my cow's tails about once per year due to sheath wear, and this wear always occurs around (and within) the barrel knots at the carabiner end, not the maillon end, so I feel that the existence of a fixed knot is a non-issue in this application. Your mileage may vary, of course; I wear my vertical gear throughout most multi-pitch cave trips and I'm apparently notorious for being hard on gear. Using a butterfly knot for this purpose always looks weird to me, but maybe some of you are doing bizarre things on rope that involve weighting both cowstails simultaneously in dissimilar directions (and I suppose, if so, I applaud you).

The overhand-on-a-bight saves minimal space -- it's certainly not any wider than an eight-on-a-bight -- and it has been my observation that most cavers who are looking to save resources and bulk in a knot might do well to spend some time working on tying properly-dressed knots with appropriately small bights. This is NOT to imply that anyone in this thread falls into this group, of course... but those reading this will know who they are.

Obviously, test after test has proven that a figure eight absorbs more energy than the alternate knots (though certainly not a shock-absorbing device like the Zyper), excepting perhaps the clove hitch, and is stronger than an overhand knot in the same application (which may or may not be relevant).
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Re: Cow's Tails Center Attachment

Postby Scott McCrea » Nov 1, 2011 4:05 pm

tl;dr
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