Who has their cowstails on separate knotts?

[global_s]

It was suggested to me recently, that following the rope access industry we should all be moving to having our cows tails independent. The set up I was shown was still made from the same bit of cord but with separate knots to the central mallion, in The Caving Technical Guide it shows them made with two separate ropes (in different colours)

Just wondered whose switched and who is sticking with a "double" cowstail. Any disadvantages to having them separate? More clutter is the only one I can think of, but I'm sure there are more.

 

[ah147]

I have mine separate.

Many advantages. Two possible disadvantages come to mind:
1. Could interfere with croll with the right hand cowstail
2. Possibly less shock absorbtion

 

[Stu]

Separate knots from a single piece of rope.

I have both knots on my left so no interference with the Croll. Not sure why there would be less shock absorption (not in my rig anyway).

I have no particular worry as such which led me to change. It offers no real disadvantages but does confer some advantages when aiding.

 

[Mark Wright]

Not sure who suggested you should follow the rope access industry and use separately tied cow's tails. The majority of rope access technicians use the method I described in another post just recently. Two long cow's tails and a short (loop) cow's tail all made from a single 4m length of rope. The two long cow's tails effectively have their own knots when used together but if using the short and a long cow's tail then one of the knots will be shared between the short (one half of the loop) and long cow's tails.

Some within the industry have questioned the independence of such a cow's tail system but it is used by the majority of the 80,000+ IRATA qualified technicians around the world. There is no evidence to suggest the method is dangerous in any way. They can be made independent by simply tying an Overhand knot in the middle of the short cow's tail loop, however most don't consider this to be necessary.

The short cow's tail loop is tied around the ventral attachment point on the harness with a rethreaded Overhand knot thus providing a good level of energy absorption due to the knot being liable to slippage. If you were to tie your cow's tails with independent ropes then a Figure 8 would be more appropriate for the end of the rope. It wouldn't be advisable to use an Overhand knot on the end of a rope due to the likely slippage. Using a Figure 8 would unfortunately increase the forces applied due to the fact Figure 8's don't slip. 

I use the standard long and short cow's tails with a single shared overhand knot to attach to the harness. I use an additional short quickdraw for aid climbing.

Mark

 

[martinm]

me. As recommended in 'Life on a Line' The knot is the weakest point. If one knot and it fails u r screwed. Two separate knots (can be same length of rope) if one fails you've still got the other one. Unlikely both would fail...

 

[Pete K]

I use cowstails formed from one section of rope that share a common Figure 8 knot.
My thoughts are that if you are worried about the condition of your rope enough to want the redundancy of the second knot then you should have binned your cowstails a long time ago. Replace annually or when worn, for the sake of a few quid is their any need to question your primary safety link?
A second knot on the mailon is double the bulk and is probably more prone to wear IMO.
Secondly, if it's not wear that is the reason for wanting a second knot, it's the fact that 2 feels safe than one, right? Put a large enough force through that knot in good condition rope to break it and your pelvis is in bits and your spine jelly surely?
At the end of the day do what you feel best for you. It's only 1 strand of rope keeping you alive anyway.

 

[Mark Wright]

I think Pete K sums it up perfectly.

Mark

 

[GT]

Always baffled me why people choose to do this, begs the question why?

Be interested to hear of any evidence of cows tails failing to justify two knots.

As a climber I've fallen more times than I care to remember on a single figure of eight knot. My cows tails are different lengths so can't see much difference in how my caving rig differs from my climbing set up, and the same set up used by probably thousands of climbers daily.

Replacing cows tails frequently and my (top tip?) suggestion would be to do a little research into getting hold of a single weight rope that yields a low peak impact on a fall factor 1. Beal ropes for example seem to deliver a pretty low hit if you fell on one of them. Trick is tying t buy it in sort lengths.

 

[Fulk]

I'm with Pete K on this.

If you're in any doubt at all about the status of your safeties, bin 'em ? they only cost a few quid.

And mmilner:

me. As recommended in 'Life on a Line' The knot is the weakest point. If one knot and it fails u r screwed. Two separate knots (can be same length of rope) if one fails you've still got the other one. Unlikely both would fail...

So ? are you suggesting that you would always be clipped into two cows's tails? If you're clipped into one and it fails, you're screwed. Or maybe I've misunderstood what you're getting at.

 

[topcat]

getting hold of a single weight rope that yields a low peak impact on a fall factor 1. Beal ropes for example seem to deliver a pretty low hit if you fell on one of them. Trick is tying t buy it in short lengths.

I got round this by buying a Beal  60m rope when I only needed a 50m...................that's quite a few cows tails out of the spare!

 

[Antwan]

Beal ropes for example seem to deliver a pretty low hit if you fell on one of them. Trick is tying t buy it in sort lengths.

I bought a 50m Beal Topgun II single rope for ?140 half price and the few occasions I fell, well, it was just like a fast lift stopping. Comfy as

Oh and I have one cows tails knot too

 

[JasonC]

I followed the advice of someone on the forum (forget who) and now have one rope with two knots and a short loop with a krab between them.  Thus giving 3 'tails': long, short and very short.  The last was supposed be a boon for awkward rebelays (which I've not yet encountered since the redesign) but it has proved comforting on very loose traverse lines.

 

[martinm]

I'm with Pete K on this.

If you're in any doubt at all about the status of your safeties, bin 'em – they only cost a few quid.

And mmilner:

me. As recommended in 'Life on a Line' The knot is the weakest point. If one knot and it fails u r screwed. Two separate knots (can be same length of rope) if one fails you've still got the other one. Unlikely both would fail...

So … are you suggesting that you would always be clipped into two cows's tails? If you're clipped into one and it fails, you're screwed. Or maybe I've misunderstood what you're getting at.

Yes, I'm a wuss. If I can clip into two things at once I will do so. However, see below:-

Taken from 'Life on a Line' 2nd edition. Highly recommended. I used this when I was re-learning SRT in 2007 and to teach my club newbies SRT soon after. Oh, and  my cowtails rope is (almost) brand new only having been used on a handful of trips, though now 7 years old. Can never be too safe is my motto...

And an afterthought would you descend a pitch on a single belay? NO! Same with cowtails, two points of connection at all times. What if the rebelay you've just clipped into fails while swapping your ascenders / descenders over. Always have two points of connection. You know it makes sense!

 

[TheBitterEnd]

We seem to love to debate "what  ifs" on here. Has a cows tail ever failed? If so has it failed at the centre knot and was it in reasonable condition?


No?  thought not.

 

[cavermark]

And an afterthought would you descend a pitch on a single belay? NO! Same with cowtails, two points of connection at all times. What if the rebelay you've just clipped into fails while swapping your ascenders / descenders over. Always have two points of connection. You know it makes sense!

You abseil on a single rope (even though it may have 2 anchor points) with a single descender when using SRT.

If the rebelay fails just after you've loaded it with one cowstail, you will fall until suspended on the SRT rope coming into the rebelay from above.  If the force from this is enough to break your cowstail knot (eg. if there is a lot of slack in the rebelay loop), it is most likely to break your spine or pelvis first.

The set up you show in your picture is the one commonly used in rope access, and has some merit for SRT (using one cowstail for the link to your hand Jammer and being versatile) but it isn't any safer than the standard set up.

 

[caving_fox]

I followed the advice of someone on the forum (forget who) and now have one rope with two knots and a short loop with a krab between them.  Thus giving 3 'tails': long, short and very short.  The last was supposed be a boon for awkward rebelays (which I've not yet encountered since the redesign) but it has proved comforting on very loose traverse lines.

^this.
The advantage of two separate tails is the possibility of having a very short tail. It is extremely useful when you do need it. Great for rigging (and de), and traverse lines. The extra knot doesn't get in the way at all.

 

[Burt]

There's pros and cons in each system. One of the reasons we don't adopt IRATA techniques in all SRT is that sometimes, underground, they just aren't appropriate. Ths may be due to more faffy bits to get hung up on, or more gear to carry that we don't want. (would you want to do SRT on a double rope system with a great big ID - probably not, and it would suffer badly in mud anyway)

Some techniques cross over from caving to IRATA and vice versa, just like ice climbing and rock climbing. It's a case of using the best system for the job - "best" being the one which is the all-round winner, not simply following a binkered "this is safest so you should use it - period" approach.

I happen to use IRATA, SPSA and LCMLA2 techniques in both work and play, but wouldn't want to be restricted to just one system for all. 

 

[Olaf]

Stupid question, but looking at the picture by mmilner with the two central knots in the cowstails cord, my first idea was "but I don't have space for an extra knot on the central mallion". But then I thought you might turn it into a feature: Has anyone tried combining the cowstails and the safety link to the hand jammer with such a setup? I.e., one long strand of rope starting at the long cowstails, one Fig8 or Overhand at the central mallion, then another Fig8 or Overhand for the short cowstails and the other end goes back to the central mallion for another knot, then another long section of rope going to the hand jammer. Obvious disadvantages would be that you can't colour code your various ropes anymore, that the short cowstails wouldn't have a barrel knot anymore, and that you'd have to replace all of safety link and cowstails at the same time (which is maybe a good thing anyway). Any other ideas?

 

[Mark Wright]

Olaf, using the spare long cow's tail for your upper hand ascender is certainly possible as cavermark has already suggested.

I wouldn't consider not being able to colour code your cow's tails as a disadvantage. If one of the long cow's tails goes to your top ascender then you've only got two left and so I wouldn't expect you would get them wrong.

There's no need to worry about not having a 'Scaffold Knot' (often incorrectly known as a 'Barrel Knot') on your short cow's tail. There will be twice as much rope in the short cow's tail when compared to the standard method of tying cow's tails so the forces applied in a fall would be significantly reduced.

A 'Barrel Knot' is actually used for joining ropes together. The 'Scaffold Knot' was used on a hangmans scaffold to attach the hangmans rope to the 'Scaffold'. They would simply throw the end of the rope over the 'Scaffold' and then tie either a double or triple twisted 'Scaffold Knot' and then snug the knot up to the 'Scaffold'. The noose would go on the other end. Double twisted 'Scaffold Knots' are the most common however the triple twisted version offers more energy absorption.

Mark   

 

[Cave_Troll]

on a side note, "life on a line" got a bit more opinionated in its second edition.
Yes the "classic" cows tail has a single point of failure. there are other single points of failure in the system.
Sometimes having a croll, safety cord knot, and two cows tails knots makes the central maiillon (single point of failure) a bit cluttered and hard to get a descender crab and braking crab into. Cavers can make a choice how to tie their knots.

IMHO Dr Merchant got a bit egotistical and preachy.....

I know of cases of people who have died when they disconnected all their cows tails and fell.
Has there been a case of failure of the central knot of a cows tail?