mountainpenguin
15 years ago
It is often pointed out that using slings as cows tails is a bad idea.
There is a video on DMM's web site that shows this rather graphically!
http://www.dmmclimbing.com/video.asp?id=5 

This is why you should use dynamic rope.
e.g.
http://www.caving-gear.co.uk/show_product.asp?id=1029  (posh and expensive)
or
http://www.inglesport.com/shop/catalog.php?category=Footloops%20%26%20Cowstails  (£5 so cheaper than a sling too!)

Also a very good idea to make sure your long cows tail is not so long that you can not reach it when fully loaded!
simonrl
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15 years ago
😮

Thanks MP.

Pretty clear message there...
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Vanoord
15 years ago
It would be interesting to see the results of a similar test of cows tails!
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mountainpenguin
15 years ago
I am sure they would if you could provide them, though in your case llama tails might be more appropriate
steve turbo
15 years ago
being a newbie to rope work what is best usage for slings ,anchors maybe..
Vanoord
15 years ago
All sorts of things.

If you're going to take a fall with slack in the system, do not do it on slings - you have to have something dynamic to take the shock out of the fall.

For anchors, slings are fine and designed for the job.

I'd also suggest - although I'm happy to be contradicted - that a sling is handy for something like dangling off a pulley, where there is no opportunity for loading.

There is, of course, a big difference between climbing and SRT - in climbing, falls are expected and you use dynamic rope to minimise the shock loading.

In SRT the aim is that you do not fall (at all) - however, there's still a chance that you could slip while clipped into cowstails and you'd get an unpleasant shock-loading if you're using slings rather than something dynamic.

Which reminds me, I must get round to buying some proper cowstails someday 😞
Hello again darkness, my old friend...
steve turbo
15 years ago
thanks vanoord thats sorted that for me ,i need to get some dynamic rope to make some..
Vanoord
15 years ago
I wonder if knotting dynamic ropes to make the cowstails risks weakening them?
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christwigg
15 years ago
"Vanoord" wrote:

I wonder if knotting dynamic ropes to make the cowstails risks weakening them?



I think you're probably going to be in more trouble if you don't use any knots.

Are you going to superglue the krabs on :lol:
simonrl
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15 years ago
"Vanoord" wrote:

I wonder if knotting dynamic ropes to make the cowstails risks weakening them?



Doubtful, dynamic rope possesses similar (but more so) elastic properties to nylon slings. It was the completely non-elastic characteristic of dyneema, crossing itself in the knot, that caused the breakage at a lower fall factor than a non-knotted dyneema sling.


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Vanoord
15 years ago
One small question, prompted by my reading of the Petzl trade catalogue yesterday evening... what's this then?

http://www.petzl.com/en/outdoor/verticality/accessories/sewn-slings-lanyards/spelegyca 

From the technical notes, it suggests that fall factor 0s are okay, 1s are dodgy (5kN) and 2s are particularly ill-advised (12kN)(ie skull and crossbones territory).
Hello again darkness, my old friend...
simonrl
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15 years ago
It looks a bit like the lanyards designed specifically for via ferrata, but, they have a shock absorbing system in them.

It is nylon though.
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Vanoord
15 years ago
Indeed - this is specifically noted as being unsuitable for Via Ferrata.
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owd git
15 years ago
"Vanoord" wrote:

I wonder if knotting dynamic ropes to make the cowstails risks weakening them?




the correct knots will provide shock absorption in the cows tails. if untied and 'relaxed' regularly, as advised by BCA rope test guru.
Discuss 😉
owd git.
simonrl
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15 years ago
Presumably some knots are better than others? Is there any guidance on this?
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Jimbo
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15 years ago
"simonrl" wrote:

Presumably some knots are better than others? Is there any guidance on this?



Take a look at this http://www.caves.org/section/vertical/nh/50/knotrope.html , makes interesting reading & just goes to show that some knots can reduce rope strength by up to 50% 😮
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Graigfawr
15 years ago
Lots of useful discussion on ukcaving forum on this topic. I learnt a lot from bods involved in rope and gear testing who posted there - e.g. periodically slightly slacken your cowstail knots as it is important that the knot absorb some of the force by tightening. I've been using SRT for 30 years but there are always new things to learn!

mountainpenguin
15 years ago
Thats they key I guess.
There is always new things to learn and we should adapt our techniques when shown evidence of a better way.

I did include a link to some cows tails for ~£5.
The last time I got some a few of us clubbed togeather and bought 30 of climbing rope as no one would sell odd lengths.

Mine are getting a bit old so I am thinking of doing the same thing again.
We used a dry treated rope thinking that it would wear a bit better.
How about a group buy ?
simonrl
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15 years ago
"mountainpenguin" wrote:

How about a group buy ?



Sounds a good idea, I'd be in.
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simonrl
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15 years ago
"Vanoord" wrote:

One small question, prompted by my reading of the Petzl trade catalogue yesterday evening... what's this then?

http://www.petzl.com/en/outdoor/verticality/accessories/sewn-slings-lanyards/spelegyca 

From the technical notes, it suggests that fall factor 0s are okay, 1s are dodgy (5kN) and 2s are particularly ill-advised (12kN)(ie skull and crossbones territory).



Having read the instructions on one of these things now (Vanoord's in fact) they are nylon and specifically designed to progressively tear to avoid a fall:

Quote:

The SPELEGYCA is made of static webbing with stitching
that is designed to rip to dissipate the energy of a fall.
This dissipation system allows the SPELEGYCA to meet
the same impact force requirements as a EN 892 dynamic
rope. In our laboratory, a factor 2 fall on a SPELEGYCA
with a mass of 80 kg yields a maximum impact force of
12 kN (EN892 dynamic rope requirement for a factor 2 fall
with an 80 kg mass = Impact force less than 12 kN).



I'm wondering though if you have suffered a fall and the thing has ripped, but you're in one piece and able to self rescue, how much of it's original strength is left? Could you use it as normal for the rest of the trip and then discard it or is it knackered straight away leaving you without cowstails?
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