Tape Security Link?

[D.Snaith]

I have just bought myself a set of the Alp Design Bafifia Cowstails (as seen on starless river) as i prefer to not have any rope attached to my harness. Does anybody know where i can get a single tail/security link (for hand jammer attachment) made from a similar material?

Thanks in advance....
:-\

 

[tamarmole]

What's the advantage of tape cowstails - security link?

 

[JoshW]

isn't it basically just webbing? couldn't you get hold of some and just sew a loop in each end yourself?

@ tamarmole - weight is the primary reason. Also means there is less rope about whilst 'on rope' so less things to get confused with the main piece of string. disadvantages are obviously the fact it's static webbing and therefore any fall is gonna hurt more so than on dynamic rope.

 

[tamarmole]

isn't it basically just webbing? couldn't you get hold of some and just sew a loop in each end yourself?

@ tamarmole - weight is the primary reason. Also means there is less rope about whilst 'on rope' so less things to get confused with the main piece of string. disadvantages are obviously the fact it's static webbing and therefore any fall is gonna hurt more so than on dynamic rope.

Shock loading something static like a bit of tape /webbing sounds a tad worrying -possibly outweighing the perceived advantages.

 

[Pete K]

Although within what could be described as 'safe' tolerances, testing has shown webbing cowstails/lanyards to impart higher impact forces to the body. There was a French test linked to on here if you use the search function.
In my opinion....
Sewn tape lanyards: Fixed length, light, neat
Dynamic tied rope lanyards: Adjustable, bulkier, cheaper, lower impact force

Personally I think 8mm rope is the way forward for footloop + safety cords.
http://dmmclimbing.com/knowledge/how-to-break-nylon-dyneema-slings/

 

[Pete K]

Perhaps more usefully to the OP, what about this: http://www.hitchnhike.co.uk/acatalog/nylon_slings_with_protective_sleeves.html

 

[andrewmcleod]

Personally I think 8mm rope is the way forward for footloop + safety cords.

I reckon ~8mm half rope is probably better than super-skinny ~8mm single rope as the half rope will have a lot more sheath and a lot more lifetime in the long run; plus you shouldn't be falling on your cows tails so you can probably afford to replace it if you ever do take a big fall. Half ropes regularly take the full force of massive whippers in climbing.

'Static' rope with knots is better than 'dynamic' rope with sewn terminations (which will still be better than static tape). I use a sling for a cowstail in climbing, where I will never fall on it because I just sit on them, whereas in caving where you do traverses and can slip it's a lot more probable that you could take a high fall-factor fall onto them. I use 9mm single rope (because that's the smallest dynamic rope I could easily buy online at the time).

That said I use 5.5mm dyneema core cord for my safety link, which means all the dynamism has to come from the rope above me (if I fall on the ascender) which probably isn't so good close to an anchor...

 

[Bob Mehew]

Link for translation of French report on cows tails is http://british-caving.org.uk/wiki3/lib/exe/fetch.php?media=rope_testing:lanyard_tests_v6.pdf, thanks to Damian for doing it.

Sewing tape yourself is not recommended.  Not sure if you could a small enough loop machine sewn to suit your requirements but cost a while ago was ?25 a go.

You can get tape cows tails with special 'rip stitching' in them so as to reduce peak loading for use on via ferratas.  I have heard of one caver using them but they cost and once used for real, have to be thrown away.

 

[Simon Wilson]

The report that Bob linked to is an interesting read but if people haven't got the time to read it all here is the edited conclusion.

Conclusion.
Cow's Tails currently on the market that are entirely manufactured, whether they be single or double, symmetrical or non-symmetrical, are not appropriate for either caving or work on ropes. In particular, Cow's Tails made from sewn tapes, in widespread use by cavers and rope workers, can pose a real risk. The tests have, in effect, shown that a Fall Factor 1 shock load could exceed 15 kN (test 6) when the recognised maximum for work equipment according to the European Standards is set at 6 kN.

From the point of view of shock absorption, Cow's Tails made from dynamic rope and knots at both ends achieve the best results. The effect of the diameter and of the weave of the rope on this shock load is not significant. Furthermore, the results are similar for knots that are well tied and knots that are badly tied, that is when the ropes cross over each other, and also whether they have been pre-tightened or not. This method also allows the lengths of the Cow's Tails to be adapted to the size of the user. Figures of Eight Knots, Overhand Knots or Clove Hitches can be used at the harness end. At the other end, a Figure of Eight Knot or an Overhand Knot and also a Barrel Knot can be connected to the karabiner. The Barrel Knot is being increasingly used by cavers and has the advantage of holding the karabiner in place. It is, in effect, completely secure and furthermore is the knot that provides the best results in both the static and dynamic tests.

 

[damian]

The Barrel Knot is being increasingly used by cavers and has the advantage of holding the karabiner in place. It is, in effect, completely secure and furthermore is the knot that provides the best results in both the static and dynamic tests.

Agree almost completely with this, with the observation that a slightly loose Barrel Knot probably comes undone more easily than, say, a slightly loose Fig of 8. Clearly no knot should be loose, but if you - like me - like to untie all your cowstail knots after most trips and clean the rope, you need to make very sure you tighten them well again.

 

[D.Snaith]

What's the advantage of tape cowstails - security link?

I have been doing a lot of bolt climbing lately and having god knows how many bits of rope attached to me becomes very cumbersome and when you need to clip in very quickly rummaging through 6 strands of rope is not practical. being able to feel what is what is ideal as i bolt on my lights dimmest setting as i can be doing it for hours on end...

 

[D.Snaith]

Although within what could be described as 'safe' tolerances, testing has shown webbing cowstails/lanyards to impart higher impact forces to the body. There was a French test linked to on here if you use the search function.
In my opinion...

There are two reasons for this not really being an issue for me, 1: my cowstails are almost always under constant load, so a fall factor of 0 is usually the case. 2:when bolt climbing we have a nice system of using dynamic rope and being belayed as if you were climbing as a back up.

 

[SamT]

What's the advantage of tape cowstails - security link?

many bits of rope attached to me becomes very cumbersome and when you need to clip in very quickly rummaging through 6 strands of rope is not practical. being able to feel what is what is ideal

That's actually the most decent and reasonable reason I can think of.  Most of the other reasons are a bit bobbins to be honest.

Weight saving!! that really is laughable.  The moment you tread in a bit of mud your carrying possibly more weight in mud on you that that.  Its not like your clinging on to an overhanging cliff by your finger tips in just a pair of lycra leggins. 
Yes, use alloy crabs instead of steel where you can, to save a bit of weight, but a few grams that tape has over 8mm rope is really neither here or there.

I know someone who seriously put their back out falling onto a cows tail,  and that was on 9mm dynamic rope.  He said the force he encountered was way more severe than he had ever imagined.  Like crumple zones on cars, even the slightest bit of give in the system has a big effect in reducing those peak forces.  That's why I would never consider using static tape for cowstails.  Not because I'm worried about the tape snapping, or bolts pulling - but purely because of the forces it would put though my body.

As for footloop and security link, the two or three meters of spare rope can come in really really handy in all sorts of out of the ordinary situations.

 

[D.Snaith]

Typical situation...

 

[SamT]

There are two reasons for this not really being an issue for me, 1: my cowstails are almost always under constant load, so a fall factor of 0 is usually the case. 2:when bolt climbing we have a nice system of using dynamic rope and being belayed as if you were climbing as a back up.

And when they're not ??

The person I mentioned above was standing on a scaff bar with the cows tail tied at their feet, then they slipped off the scaff bar. full fall factor 2.  Wasn't an entirely unusual place and they were just re-arranging some stuff.

Of course you'd never never ever ever do that would you, you're a good boy scout.  :spank:

 

[SamT]

How about an A typical situation.

I don't bother with my seatbelt in the car, as most of the time,  I'm just driving normally and not crashing into stuff head on.

 

[D.Snaith]

That's actually the most decent and reasonable reason I can think of.  Most of the other reasons are a bit bobbins to be honest.

I completely agree with you, weight has never bothered me. I prefer my steel krabs over any of the others and im happy sacrificing the weight for durability and higher KN ratings. Also, when you are doing something like this you can easily leave a tackle bag at the bottom of a pitch and have people pass them up to you on a bit of accessory cord if needed...

 

[Bob Mehew]

For what it is worth, I have a large set of data awaiting writing up but the head line is forces from dropping a 100kg mass on a 0.75m length (a long cows tail) of brand new 10mm dynamic rope with FF 1.2 using Fig 8 or barrel or overhand knots gave on first drop peak force of 6kN.  There is an HSE report on "Survivable Impact Forces on Human Body Constrained by Full Body Harness" see http://www.hse.gov.uk/research/hsl_pdf/2003/hsl03-09.pdf. 

 

[D.Snaith]

And when they're not ??

The person I mentioned above was standing on a scaff bar with the cows tail tied at their feet, then they slipped off the scaff bar. full fall factor 2.  Wasn't an entirely unusual place and they were just re-arranging some stuff.

Of course you'd never never ever ever do that would you, you're a good boy scout.  :spank:

Traverse lines are always placed at chest height therfore a fall factor of 2 would be impossible...

 

[SamT]

I'm just playing devils advocate really - but are you telling me you never ever do anything other than caving traverses, on perfectly bolted traverse lines at chest height.

:-\