- Jun 11, 2015 at 4:02 pm #1329782
Wanted to make a cows tail for rock climbing, clipping at belay anchors for rappels etc.
Here is what I came up with after reading a batch of things.
"When used properly, these systems can be safe and strong, but when used improperly, they can lead to fatal accidents.A 2007 incident on the Grand Capucin near Chamonix, France, exemplifies the danger: A climber fell less than two feet onto the Dyneema sling attaching him to his anchor; the resulting impact broke the anchor sling, and the climber fell to his death."
It uses dynamic rope with a half of a double fisherman's at the far end and a water knot on the harness which makes also a short lanyard too.
Anyone see issues with this? Will the water knot roll with high force on the long end?Jun 11, 2015 at 7:08 pm #2206506Jeremy and AngelaBPL Member
@requiemLocale: Northern California
I wouldn't tie a loop that way. I'm not sure how to describe what you tied without using far too many words, but I expect it will be vulnerable to rolling. Please review the difference between a water knot and an offset water knot (aka flat overhand or euro death knot) to see why.
Edit: Hope this image will simplify things. The top one is an overhand on a bight, the bottom one is similar to your knot.
Edit 2: Please also review this PDF to ensure the barrel knot has also been tied correctly: http://www.irata.org/safety_notices/Safety%20Bulletin%208%20%20Dangerous%20knot.pdf
Traditionally the water knot (aka tape knot) is used for tying two ends of webbing (tape) together (a bend). Forming loops from a bight on the end of rope or cord is done using figure-8s or overhands-on-a-bight. This is so common that I can't easily find data on the strength or behavior of a water knot tied in cord.
-JJun 12, 2015 at 11:22 am #2206738
You get at the issue well. I am looking for a loop knot that will be secure either pulled on the tail or inside the loop. A figure 8 rolls (death knot) at low force, an overhand knot at the higher limits of rappelling force. So am looking for knot that wouldn't roll when the force is applied either at the far end cows tail or force inside the loop around the harness.Jun 12, 2015 at 11:25 am #2206739Chad LorenzBPL Member
@chadlLocale: Teton Valley, Wydaho
Alternatively Sterling makes a PAS out of nylon…called the Chain Reactor.Jun 12, 2015 at 11:31 am #2206742
Neither accessory cord or nylon web is recommended as dynamic enough for above anchor falls.
Maybe a double fisherman's for the harness loop with the dynamic rope?Jun 12, 2015 at 11:33 am #2206743Andy StowBPL Member
@andysLocale: Midwest USA
How about an alpine butterfly for the loop, and a figure eight or a clove hitch for the carabiner end? A clove hitch would make it adjustable, and require less rope, but must be cinched tight to be safe. A stopper knot would stop it from pulling right through.Jun 12, 2015 at 11:36 am #2206746Chad LorenzBPL Member
@chadlLocale: Teton Valley, Wydaho
"Gold standard" has always been to clove hitch in to the masterpoint carabiner near your tie in?Jun 12, 2015 at 12:42 pm #2206760Jeremy and AngelaBPL Member
@requiemLocale: Northern California
Is there a particular reason you would be ring-loading the loop? It simplifies things if you don't do that. If it's only to connect a belay device, you can use a bit longer length of cord and tie an additional knot for that.
Also, don't forget the strength of your anchor; a high impact fall on it should be avoided if at all possible. Thus, it's a better idea to avoid moving to a position where you could take a factor 1 or 2 fall on the anchor.
With that in mind I'm personally happy with taking a 60cm sewn nylon sling and tying a knot near the middle: one end gets girth-hitched to my harness, the other end can be clipped to the anchor, and the knot near the middle is used to clip in the belay device for rappelling.
Or, as Chad suggested, since you're already tied into the climbing rope, just use the rope to tie in with a clove hitch.Jun 13, 2015 at 7:53 am #2206917James holdenBPL Member
Yr overthinking it
Just use a figure 8 on one end and a barrel knot (or fig 8) at the other
And to be blunt a nylon sling will work just fine ….
The most important thing is to train yourself to keep slack out of the system
For the most part the deadly personal anchor thing is a red herring in climbing … Not to say it doesnt exist, but its easy to avoid with proper technique
Remeber that the metolius PAS is the most popular commercial recreational climbing anchoring system and its not like folks are dying all over the place from emJun 13, 2015 at 10:23 am #2206954
Not tied to the rope (think setting up exposed top roped sling shot anchors from above or via ferrata. So in most cases a barrel and fig 8 would be fine, but also was thinking of using the loop around the harness as short tail for ascending, belay loop etc. Maybe I will just stick with this http://www.iscaoutdoorshop.co.uk/images/source/cowstail.png.Jun 13, 2015 at 6:00 pm #2207012Will ElliottBPL Member
@elliott-willLocale: Juneau, AK
It's pretty intriguing to consider all these things but I really don't think you need to rig up a specialized piece of gear for this. It's one more thing to worry about and isn't versatile. Like others have said, I'd just use clove hitch your tie in whenever possible, and clip in with a runner whenever convenient and when rappeling. Then you never have to worry about all the things this setup has already presented, like coming untied, or getting old, or loading awkwardly, or being left behind, etc. Good luck!Jun 15, 2015 at 1:57 pm #2207444AnonymousInactive
A more experienced (than i) climbing partner of mine got some compliments on his leash. He used a Runner, Tied in the middle to his harness (didn't see knot), and ran equal lengeths to carabiners attached to his gear rings on both sides.. The setup was shorter for similar weight but allowed him to more easily clip in with either hand. The "unused" side backs up your only knot by not allowing it to pull thru (both the carabiner size and that its clipped to a non-weightbearing gear loop)..
Novice question here, on the knots proposed. But the knots aren't backed up on either side. When I read the american alpine clubs anchoring guides I thought they were more supportive of backing up your knots. My real life instructors have said its fine if you leave sufficient tail on your knots as you've done.Jun 15, 2015 at 9:45 pm #2207588James holdenBPL Member
a fig 8 knot with a ~ a fistful (5") of tail does not need to be backed up providing its well tied and snug
a bowline tie in should absolutely be backed up with some kind of stopper knot
for personal tethers as i indicated before …. KISS … a sling works fine
now if yr climbing above the anchors, some kind of dynamic setup is needed … a short section of dynamic climbing rope in new conditions with knots at both ends has been proven to limit the fall forces to ~6-8 KN … or theres other specialized gear one can get ….
;)Jun 20, 2015 at 5:12 pm #2208778kristen bucklandSpectator
so are you doing class 5 rope climbing? A Via Ferrata? Free soloing?Jul 2, 2015 at 5:51 pm #2211798r mBPL Member
Cavers construct similar things, in differing configurations.
Like one may be to tie an overhand off center and attach that to your harness (you'd have to rethread the knot to attach it to a climbing harness's belay loop) and use the two differing length ends as your two attachment points.
Some folks teach using a moderate length sling girth hitched to your harness, tying a knot halfway and attaching your abseiling device here, while using the end of the sling as a tether. The niceness when abseiling there is that if you wish to use a prussik, you can attach it to your belay loop and not worry about it hitting the device, which might look like this: http://alpineexistence.com/wp-content/uploads/2014/03/photo-2.jpg
Naturally there are a million variations, and as someone above eluded to people have been using dyneema slings, nylon slings, nylon ropes, for years and there's not much in the way of accidents from gear failing.
Personally I occasionally use one of the older metolius PAS (that don't pass the UIAA requirements come to think of it). I was OK with rope tethers for caving, but for climbing it's more bulk on the front of your harness, where you might be trying to also thread in two half ropes. There isn't a knot as low profile or as easy to add/remove when needed or not needed as a girth hitched sling.
As to your knot choice, it's a different loading situation to the commonly tested EDK so obviously those test results don't apply. I've generally heard it called a ring knot, and heard mention of it being used as a tie in knot: eg: 5th post: http://www.mountainproject.com/v/ring-bend-as-tie-in-knot/107108289#a_107108555
I'm not saying its safe, or unsafe. It's relative lack of use just means most people don't seem to know much about it, myself included.
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