Poll: What kind of cowstail do you use most?

[ek]

In the wake of the June 2006 cowstail study (which was translated into English in 2008), I am wondering about the current distribution of cowstail types. One reason I am interested in this is that I want to collect information about what is common practice, to help me to defend SUOC's transition from our Petzl Spelegycas (many of which are aging and must be retired soon anyway) to cowstails tied from dynamic rope, should the University or some other party question our using a product we make ourselves when a factory-made product is "available."

I put "available" in quotes because to the best of my knowedge the only factory-made cowstail that has been through extensive real-world testing in a variety of sport caving situations is the Petzl Spelegyca. And I have a rather dim view of the Spelegyca, since it came out (see the above study) that when both arms are clipped to the same anchor point (or, I would presume, anchor points that are close or otherwise at the same level), the stitching that rips out to reduce peak loading fails to deploy entirely and (in a static drop test) yields a force of 15kN. (Or, to put it nontechnically, the thing doesn't work.)

Anyway, for those of you who choose to participate in this poll, I wanted to disclose my personal interest and what I intend to use the information for. I understand that this poll is nonscientific (after all, if it were, I would have to first obtain approval of a board on research with human subjects--i.e. you folks, the pollees), and I will not represent it as scientific.

Please do not be discouraged from responding by my own position. If you use and champion the Spelegyca, please answer the poll and, if you wish, post to advance your views.

My hypothesis (emphasizing again, though, that this is not a scientific study) is that most cavers use cowstails that are tied from dynamic rope. I want to get something of a better idea about whether or not I'm right.

In this poll, I am asking only about cowstails with two arms of different length (i.e. asymmetric double lanyards). If you use separate cowstails and want to be heard, then please just post in the thread. If you use a three-cowstail system, with asymmetric double lanyard and, for your upper ascender, a separate single lanyard, then please answer regarding just your asymmetric double lanyard, and if your single lanyard to your upper ascender is different, feel free to post about it in the thread.

I apologize for the complexity of this poll. It's a complex issue that I felt would not be adequately examined with only a couple choices.

Finally, I want to disclose that I am voting in this poll, and I am selecting "One tied from dynamic rope (i.e. high stretch, climbers' rope). And I tied it myself, or it was tied for me by an acquaintance." I made the poll not to allow re-voting, so me voting in it now (before anyone else has voted) and disclosing that I am doing so actually provides more certainty about the degree to which I might be able to manipulate the results.

[fuzzy-hair-man]

I reckon if they question you tying your own cowstails for the club let them have that report it seems pretty conclusive to me you can't generally (unless you buy a pre-tied one) buy a cowstail which performs as well as ones tied dynamic rope.
If the club are trusted enough by the university to tie the knots in rigging then surely the club can also be trusted to tie the knots in cowstails. If it helps I'm in a university club and we tie our own cowstails so there's a precedent.

[kip]

nice poll - but before you post with enthusiasm fellow cavers just take a wander out to the shed and ask yourself how old is my cowstails and them biners on the end. Most folk I find who get on their high horse about the type of cowstail material and design are standing their with a rotten old piece of tat i would never fall on. Remember these are our link to staying off the floor waaaaaaaaaaaaaaaaaaaaay below look after them and this could be a timely reminder to all to all to give them some loving. Cant wait to see the result ps i own the sewn response even after reading the report many years ago i'm still on em.

[ek]

That's a good point. I would far rather fall on a one year old piece of static line than a ten year old piece of climbing rope.

On the other hand, I think I would rather fall on a ten year old piece of climbing rope, provided that it appeared intact, than a brand new piece of webbing.

Also, what about the carabiners at the end? I don't think that there's a significant risk associated with continuing to use an old carabiner that appears to be in good condition upon inspection.

[Dwight Livingston]

nice poll - but before you post with enthusiasm fellow cavers just take a wander out to the shed and ask yourself how old is my cowstails and them biners on the end. Most folk I find who get on their high horse about the type of cowstail material and design are standing their with a rotten old piece of tat i would never fall on. Remember these are our link to staying off the floor waaaaaaaaaaaaaaaaaaaaay below look after them and this could be a timely reminder to all to all to give them some loving. Cant wait to see the result ps i own the sewn response even after reading the report many years ago i'm still on em.

That's the best part of tying your own. There's no reason to procrastinate about tying a new one.

[MUD]

That's a good point. I would far rather fall on a one year old piece of static line than a ten year old piece of climbing rope.

On the other hand, I think I would rather fall on a ten year old piece of climbing rope, provided that it appeared intact, than a brand new piece of webbing.

I'd rather not fall at ALL!

[ek]

I'd rather not fall at ALL!

We can reduce the risk of taking big falls onto our cowstails by rigging properly, but we cannot reduce it to zero. We do, however, have absolute control over what our cowstails are made of.

[Ralph E. Powers]

I've three cowstails that I can use. One I made myself out of 1 inch tubular webbing that is hand sewn with heavy duty nylon thread. The stitching goes up and back down to where there are four rows of stitches roughly 10 inches long. The stitching goes up one way and back down the same line the opposite direction before moving on to the next row. The loop(s) are folded over themselves and stitched in the same manner but with only one row. The middle is a butterfly knot.
My other is a 9mm dynamic cord tied with knots, that too I made myself.
The last one is made from 6mm cord tied into a purcell climbing system. This particular item (hand tied because it's designed to be user specific) is very versatile and using it as an impromptu cowstail is one of them.

http://en.wikipedia.org/wiki/Prusik_knot A Purcell Prusik is a related cord popular among cavers and rope-rescue people. A somewhat longer loop than the normal Prusik is used around the rope, then a second Prusik is used around the cord loop itself to form a foot loop. The foot loop is then easily adjusted in length and position.

I've had both for a number of years and they've served me well. Neither have taken falls of any type but they have suspended me from traverse anchors or when I needed to cross anchors on a multi-pitch drop. I do not however use them as others use cowstails as part of their rigging for frog systems. I have my QAS for the safety and the cowstails are for when I come across technical stuff.
As a "poor-man's caver" this is the best I can do at the moment. Perhaps when thing$ are better I will get one of those nice store-bought ones like the Petzl Spelegyca or something akin to it.

As it was said, the idea is NOT to fall. Proper rigging, proper placement of the equipment needed at the moment and bracing one's feet where possible. I've done several technical traverses and technical euro-style rebelay crossings. They are fun and challenging to do and I feel a very important part of one's advanced vertical training.

[Carl Amundson]

I was getting ready to replace my cow-tails at the beginning of the year and that's when I found the cow-tail study mentioned at the top of this thread.
I found very informative and suggest that everyone should read it.

My current cow-tails is made of 8.6 mm dynamic rope with a figure 9 in the middle and barrel knots securing my 'biners.
Along with this I use a separate QAS attached to my harness with an adjustable webbing strap from GGG.
My foot ascender is also a separate system using GGG webbing strap and double footloops.

I like having webbing straps for my QAS and footloops because they do not stretch.
I understand it could cause issues if I take a fall, but it makes my frog system more efficient in the long run.

[ek]

The material that the tether to your QAS and/or upper ascender is made of is irrelevant to your frogging efficiency. Think about it--this is never weighted when you're climbing. The tether to your upper ascender is a safety strap.

The material that your footloop is made of, on the other hand, is irrelevant to shock-absorption in a fall, because you don't fall onto your footloop. If you're standing in your footloop when you fall, your leg will bend just fine. And if it didn't (besides how your leg would then be your primary concern), this would be no worse than falling onto your Croll...which is usually what would happen anyway.

Therefore, if you want to maximize both safety and efficiency, your ascender tethers in a frog system should be made from dynamic rope, and your footloop should be made from as static a material as possible--Spectra or Technora. (Nylon webbing does stretch significantly, just not nearly as much as nylon rope, and far less than small-diameter nylon accessory cord. When I switched from nylon webbing to Spectra cord for my footloop, I instantly noticed an increase in efficiency. On the topic of webbing not really being static, I've actually seen anchor webbing stretch perceptibly under the load of a very jerky rappeller! )

Furthermore, and while I know this has been discussed before...there is currently no 8.6mm dynamic rope that is rated for use as single rope, i.e. for use in a single strand as the primary shock-absorbing component of a fall arrest system. Half ropes are always backed up by another half rope, and twin ropes are always used in pairs, run in tandem through each anchor in rock climbing. So, IMO, the only kind of rope that is really suited well to cowstails is dynamic single rope. Of course, half rope does have greater elasticity and thus lower peak impact forces, so that would be an argument for using half rope. But even in a static drop test, the Chamonix cowstail study shows that the difference is not significant for cowstails, perhaps because (and this is my own suggestion, and not from the paper) there is more extension in the tightening down of knots tied on thicker-diameter ropes, which approximately cancels out the greater stretch of the thinner-diameter ropes.

It's unlikely that a half rope, tied with a figure-eight on one end and a barrel knot on the other, would rupture due to a fall. However, due to the thinner diameter, it is more likely to be cut if run against a sharp edge in a fall. This is the primary reason why just one dynamic half rope should not be used by itself for leading--the idea is that in the unlikely but possible event that it does break, you'll fall some more and the other half rope will catch you.

[NZcaver]

Furthermore, and while I know this has been discussed before...there is currently no 8.6mm dynamic rope that is rated for use as single rope, i.e. for use in a single strand as the primary shock-absorbing component of a fall arrest system.

OK, here's a quick question. If you were forced to make a choice, would you rather use a cowstail tied in 8.6mm dynamic rope, or in, say, 11mm low stretch rope? I'm just curious how people would feel about this.

[ian mckenzie]

The smaller one, whether it's dynamic or static. I've used 11mm for tails before and I find it's just too bulky.

[Carl Amundson]

OK, here's a quick question. If you were forced to make a choice, would you rather use a cowstail tied in 8.6mm dynamic rope, or in, say, 11mm low stretch rope? I'm just curious how people would feel about this.

I also find that 11mm rope is too bulky for use as cow-tails.

In the Chamonix laynard test, the BEAL Ice Line 8.1 mm (half rope) performed very well in cow tails made entirely of knots.
This testing was done with an 80kg mass and the impact force was less then experienced by some of the larger diameter single ropes.
I believe that you are correct in saying that this is due to the greater elongation of this type of rope (half rope).

[ek]

It's not its elastic performance in a fall I question, but (as I detail above) its increased likelihood of being cut against a sharp edge in a fall.

That said, I would personally choose the 8.6mm dynamic half rope over the 11mm static rope in a heartbeat. The 8.6mm dynamic rope stretches plenty, performs well in testing, it doesn't break in a FF2 drop test, and the likelihood that a rope will but cut against a sharp edge increases with peak impact force anyway, so the greater benefit in cut-resistance given by the thick static rope is negligible.

However, I would feel kind of silly in using 8.6mm dynamic half rope, as dynamic single ropes are available from 8.9mm (the Mammut Serenity) and up, and Sterling Nano 9.2mm rope is available in short sections from Sterling distributors.

In fact, Sterling kindly sent me 16 meters of it for free (and they paid the shipping too!) when I inquired about the possibility of getting short sections of it and expressed to them my belief that it would be a good choice for cowstails. This is the rope that I am currently using for my own cowstails. 16 meters was way more than I needed, so I gave most if it away to other cavers, both in my grotto and not. When it comes time to retire my cowstail, I intend to buy more. Here are the instructions on purchasing short lengths, given to me by John Branagan, Sterling's Outdoor Product Manager for Climbing, Camping, Water, Hunting & OEM:

You can contact the following places and let them know that you would like to order the Nano 9.2mm "Prime Short" or per meter cut lengths.

Leap-Ware - 828-713-0633 http://www.Leap-Ware.com
OR
R & W Enterprises - 508-997-3933 - 800-260-8599 -

If we have prime shorts in stock it will be a bit less expensive then the per meter cut lengths. If you order a prime short make it clear that what lengths you can take i.e. No shorter then x length ** note 1 ft = 3.28

For those of you who would prefer to stick with PMI but want a piece of single dynamic rope thinner than the 9.7mm Arete that's up on Inner Mountain Outfitters (which I believe is the only speleovendor that sells short lengths of dynamic rope), you could probably special-order shorts of PMI's 9.4mm Elite from IMO. If that fails, you could probably go through PMI directly. Back when I was contacting as many manufacturers as I could about getting short lengths of dynamic rope for cowstails, I heard back from Jillian Bartlett (a PMI customer service rep), who offered to send me short lengths of the 9.4mm Arete and charge only for shipping. (I didn't take her up on the offer because the free 16 meters of Sterling Nano 9.2mm rope was already on its way.)

[wyandottecaver]

Surprised my cowstail is not shown. A 9mm static pre-tied and purchased from Inner mountain. I have 2 and they work wonderfully. I used a dynamic cowstail for about 3 months until it looked like it had been through a cheese grater.... My cowstail is adjustable using a prusik-like knot and at maximum extension is about 2.5'-3' long. I have never climbed 3ft above my anchor and fallen. I HAVE fallen from the anchor. It is embarassing but did not seem terribly life threatning. I also don't use tiny french made harnesses that impart injury just by being worn I can offer no empiric evidence, but I suspect that the design of the HARNESS is a huge factor. I like mine wide and comfortable...not necessarily effecient....