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Dyneema and Nylon Drop Tests

PostPosted: Mon Jun 14, 2010 5:37 pm
by welle
This is quite eye-opening: http://www.dmmclimbing.com/video.asp?id=5 (reposted from Gunks.com)

This should put to rest all arguments about using dyneema slings and daisy chains as PAS.

Re: Dyneema and Nylon Drop Tests

PostPosted: Mon Jun 14, 2010 6:46 pm
by crackers
welle wrote:This should put to rest all arguments about using dyneema slings and daisy chains as PAS.


uh...the video is about using slings, not about using PAS type systems nor about using daisy chains. Let's not comingle different things.

PostPosted: Mon Jun 14, 2010 7:00 pm
by Autoxfil
The most important thing to get from that test is to not fall on anything static. Even the nylon generated big numbers which could rip nuts or cams out, although it didn't break.

If you clip in with a sling, don't climb up to or above it!

Re: Dyneema and Nylon Drop Tests

PostPosted: Mon Jun 14, 2010 8:56 pm
by mvs
crackers wrote:
welle wrote:This should put to rest all arguments about using dyneema slings and daisy chains as PAS.


uh...the video is about using slings, not about using PAS type systems nor about using daisy chains. Let's not comingle different things.


What do you mean different? I just tied in to the anchor with a Dyneema sling...viola, it's my PAS. As such I think the results are extremely relevant when thinking about building or tying into anchors.

Really good video.

PostPosted: Mon Jun 14, 2010 10:29 pm
by rasgoat
This is a great video.

What I have learned is do not tie a knot in Dyneema, I would say even on/especially for an anchor built with dyneema.

Also, tie into the anchor with a clove hitch on your climbing rope, not any sling whatsoever,so if there is a fall from the anchor with slack in the rope, the stress on the system is greatly reduced. Of course on rappel, this would not make sense, I would use a nylon sling to tie myself in.

I suppose the only real use I feel comfortable with for dyneema is for my extendable runners fo the weight and size factors.

I would say for anchors, since you should not tie a knot in Dyneema, it should be avoided unless of course you are comfortable with the sliding X sytem.

PostPosted: Mon Jun 14, 2010 11:11 pm
by JackCarr
The most important thing to take from the video is make sure there is no slack in the system. If you're tied into an anchor and the sling is tight then any fall or slip will be next to nothing and stopped. Slack increases the force through the sling, hence why they broke on this test.

If in doubt, clove hitch with the rope. If using a cows tail to stay safe while you set up an abseil, again, make sure there is minimal slack!

PostPosted: Mon Jun 14, 2010 11:25 pm
by The Chief
JackCarr wrote:If in doubt, clove hitch with the rope.


It is my primary method of initially tying in. Has been for well over 40 some years as I was taught to on my very first outings. Secondary is a Met PAS.

The Clove Hitch procedure has been pushed aside with the advent of fancy gear. This makes absolutely no sense as one is already tied into the rope.

Oh well.

PostPosted: Tue Jun 15, 2010 12:10 am
by rasgoat
Again, the clove hitch is really awesome.

PostPosted: Tue Jun 15, 2010 6:16 pm
by Hotoven
I didn't watch the video yet, but from what I gather, it would be dangerous to use these?

http://www.summithut.com/products/nano-wire-express-quickdraw/

So no sport climbing with dyneema dog bones?


I admit I don't know much on the subject, just wondering.

PostPosted: Tue Jun 15, 2010 6:39 pm
by welle
your link is not working.

but to answer your question, I'd still use dyneema for draws - since your climbing rope would absorb much of the impact force. the argument was against direct from harness tying in into an anchor with static slings...

PostPosted: Tue Jun 15, 2010 8:47 pm
by Pallando
I've never done trad or multi-pitch climbing, and I've always used a Metolius PAS when rapping off of sport climbs. Can someone explain the clove hitch procedure you're talking about? I tried searching for it, but couldn't find anything. It sounds like a much better idea thank risking a static anchor that might get slack...

PostPosted: Tue Jun 15, 2010 9:59 pm
by seanh
Clove hitching the rope to your anchor won't really help you to rap from a sport climb, because by definition you need to untie from the rope to set up the rap.

But, it is the only way anyone should tie to an anchor during a multi-pitch climb. Why anyone would choose something over this method is beyond me.

Re: Dyneema and Nylon Drop Tests

PostPosted: Wed Jun 16, 2010 12:41 am
by crackers
mvs wrote:What do you mean different? I just tied in to the anchor with a Dyneema sling...viola, it's my PAS. As such I think the results are extremely relevant when thinking about building or tying into anchors.


Sling is not equal to PAS.

PAS is a trademark owned by Metolius but used here by me as a generic term of the art to denote a personal anchor system created by a number of quite small slings permanently affixed to each other. The entire reason behind a PAS is that you can easily clip into an anchor with a minimum of slack by picking the appropriate section of the PAS.

Image

This is not the same thing as a sling. The video has everything to do with using a sling and indirectly it has stuff to do with a PAS or even a good old fashioned clove hitch.

PostPosted: Wed Jun 16, 2010 6:12 am
by mvs
Clearly, I misused the term PAS to mean any kind of anchor system a person constructs to hook themselves into an anchor. I didn't realize the term belonged to a particular product or family of products. Thanks for the clarification, Crackers.

PostPosted: Wed Jun 16, 2010 6:48 am
by Tbenner
Always back everything up. Never trust One piece of gear. slings are very strong. all but the most unusual cases do slings fail. Rope, rope drag, belayer, rope slide through belay device, you and the occasional gear pop all absorbs impact. Its like catching an egg you just dont stick you hand out and try to catch it, it will break. you reduce the impact by lowering you hand with the egg to catch it, thats sort of how the system works. But every situation is different and sometimes you just got to take what you can get.