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prusiking with dyneema slings
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Oct 29, 2007
I carry little 7mm prusik slings when I'm on multipitch just in case I need em for something. I use 24" mammut dyneema extendos, and was wondering if anyone has any experience trying to prusik with these things so maybe I can forgo that one extra thing on my harness. Jesse Davidson
From san diego, ca
Joined May 30, 2007
70 points
Oct 29, 2007
I have heard that they can be used for that, but I tried it once and couldn't get it to work as desired. I can't exactly remember the problem; I think maybe it got stuck and was too hard to release. Joseph Stover
From Batesville, AR
Joined Dec 8, 2005
863 points
Oct 29, 2007
I've tried that once also and I put a caribiner into the mix, wrapped the sing around the rope and a caribiner at the same time and it seemed to work all right. BrianWinslow
From Concord, NH
Joined Mar 19, 2007
1,010 points
Administrator
Oct 29, 2007
For webbing try using a klemheist knot. It seems to work fine on dyneema slings.

ttp://en.wikipedia.org/wiki/Klemheist_knot
John McNamee
From Littleton, CO
Joined Jul 29, 2002
1,923 points
Oct 29, 2007
Dyneema/spectra melts at like 290 degrees F, which is a possible temperature to reach if you jug fast and your prussik/klemheist knot is slipping a lot (try it! you can totally melt that stuff). So add a couple extra raps if you're going to use spectra, and inspect the slings regularly. Tico
Joined Feb 24, 2006
9 points
Oct 29, 2007
A few weeks ago I used a 24" dyneema runner as a backup for an ascender. I went about 140 feet. I used a prussik. It held very tight, and easily slid up rope. I actually liked how it performed more than regular cord, however I am not sure how much wear and tear it would get if you had to do a really long ascent with it. dcohn Cohn
Joined May 28, 2006
429 points
Oct 29, 2007
I've done it with a klemheist before. It works but like mentioned above is hard on the sling. Even after jugging only 100' it showed wear that a normal prussik (7mil) cord would not. It also seems to be more time consuming than a prusik cord. So it works in a pinch, but tie back up knots in the rope as you ascend in case you burn through. Jordan Ramey
From Calgary, Alberta
Joined Jun 15, 2006
4,390 points
Oct 29, 2007
thanks guys. I was playing around with a klemheist tied through a carabiner, and also a bachmann, in my living room, and it seemed like it would work pretty well. Guess I'll be testing at the crag this weekend and if all goes well, no more 7mm prusik cords for me. Just a smart ass observation: if I actually melt through the sling, what good are backup knots going to do for me? Jesse Davidson
From san diego, ca
Joined May 30, 2007
70 points
Oct 29, 2007
Jesse Davidson wrote:
Just a smart ass observation: if I actually melt through the sling, what good are backup knots going to do for me?

Uh, keep you from hitting the ground, maybe?
John Hegyes
From Las Vegas, NV
Joined Feb 2, 2002
4,614 points
Oct 29, 2007
I'm also with the Kleimheist. Yes, dyneema/spectra melts at a lower temp, but just take it easy while using it. Also to note, aren't the slings covered with a nylon sheath? Which would help prevent a problem with friction.

For repeated use, probably not the best material to slide on the rope, but it will work to get you out of a jam if you need to use your slings.

If you can get a Bachmann to work, more power to ya. I'd stay away from a prusik as a friction hitch in using a sling.

With respect to the "back-up knots", I think the idea is to tie in short -- clip a quick 8 on a bight from your mainline below your hitches into your harness with a locker. That way, if your hitches fail, slings get cut, or your jumars are used incorrectly (similar topic, just a different application), your main fixed-line will catch you.
Buff Johnson
Joined Dec 19, 2005
1,511 points
Oct 30, 2007
After a few bad experiences melting the edges of a dyneema sling while using it for an autoblock I stay away from using dyneema in any friction knot. A foot long piece of 5mm perlon works much better and takes up less space and is lighter. I think you will find it lasts a lot longer too. Kevin Stricker
From Evergreen, CO
Joined Oct 20, 2002
638 points
Administrator
Oct 30, 2007
Having seen the effects of sliding up and, worse, sliding down on these low-melting point slings, I'd make sure I had a good backup. This isn't my first or second or third choice. Leo Paik
From Westminster, Colorado
Joined Jan 1, 2001
23,588 points
Oct 30, 2007
What I've found works with about every anchor & self/buddy rescue application is about 13-15' of the newer 5.5mm tech-cord with the nylon sheath -- mainly because the cord is strong, workable, & has a nylon sheath. I also keep about 13' of 5mm perlon as leader rescue cord because the 5.5 always seems to end up as the anchor rigging.

All these cords are light & capable of their intended application, which are utility purposes -- always back-up everyone's life with the mainline/climbing rope.
Buff Johnson
Joined Dec 19, 2005
1,511 points
Jan 9, 2013
I like a purpose built or cut length of aramid cord. strong, durable, loads of friction. best of all, virtually un-meltable. I use one from Blue water. the additional benefit of the Blue water Vt, is its ability to be re-purposed from autoblock/emergency ascender duty, as a single line Valdy, for descending a loaded line.

its a little big but its versatility keeps it on my harness.
Rob Warden, Space Lizard
From Springdale Ut
Joined Dec 19, 2011
132 points
Jan 9, 2013
Rob Warden, Space Lizard wrote:
I like a purpose built or cut length of aramid cord. strong, durable, loads of friction. best of all, virtually un-meltable. I use one from Blue water. the additional benefit of the Blue water Vt, is its ability to be re-purposed from autoblock/emergency ascender duty, as a single line Valdy, for descending a loaded line. its a little big but its versatility keeps it on my harness.


Sterling Rope makes a similar product- pre-sewn, just big enough for a prusik loop. I keep one on the back of my harness just in case. Two wraps around any diameter from 6mm to 1/2" and it'll grab. Also rated to 12kn or so, so good as a sling in a pinch.
John Wilder
From Las Vegas, NV
Joined Feb 1, 2004
2,461 points
Jan 9, 2013
I've used the bachman for ascending after rapping to get stuck gear that my second couldn't get out. Almost like having ascenders. As far as having to set up a z rig using them I haven't tried.

Bachman
"H" Lampasso
From Manitou Springs
Joined Feb 13, 2006
114 points
Jan 9, 2013
John Wilder wrote:
Sterling Rope makes a similar product- pre-sewn,


the Sterling hollow block is very nice to, however I have had mine be a bit of pain binding really compressing over itself which makes me like it less than the Blue Water VT which is also stronger at 16KN
Rob Warden, Space Lizard
From Springdale Ut
Joined Dec 19, 2011
132 points
Jan 10, 2013
Rock Climbing Photo: bachman knot
bachman knot




"They" say this is a good one to use with ord and slings
Mark Sensenbach
From San Luis Obispo,CA
Joined Jan 8, 2013
5 points
Jan 10, 2013
I think you can easily climb a rope using slings. The problem with ditching your prussik cords is you don't have a decent brake hand backup on raps IMO. When it comes to load release function while doing self rescue.. I don't know how well the dyneema would do. Jarmland
Joined Apr 13, 2012
10 points
Jan 10, 2013
It works but it can put damaging wear onto dyneema which compromising its strength for regular use. Use dyneema for friction knots only if it is necessary. My $0.02 bradyk
Joined Jun 7, 2010
148 points
Jan 10, 2013
I've always been puzzled at the persistence of the Kleimheist knot, which fairs poorly in every test I've seen compared to various alternatives. The only possible explanation is the strength of uncritical tradition.

Years ago, it was already known that the Hedden knot (1960, Summit Magazine), which is a Kleimheist tied "upside down" (so: start by winding up rather than down) held better than a Kleimheist. (See, for example, the comments on storrick.cnc.net/VerticalDevic.... Since then, various forms of the FB-knot have proved to be even better.

For the FB knot, see gudelius.de/fb1.htm. Here's the picture from that site:



I'd add that the instructions to do three wraps and a downward wrap would be more simply rendered as "four wraps."
rgold
From Poughkeepsie, NY
Joined Feb 15, 2008
549 points
Jan 10, 2013
the kelmhiest continues because its fast and basic. I Like it with nylon slings I just add a lot of wraps to increase hold friction. however my aramid VT prussic is badass Rob Warden, Space Lizard
From Springdale Ut
Joined Dec 19, 2011
132 points
Jan 11, 2013
Nah, doesn't explain it. The Hedden knot is literally the Kleimheist upside-down; just as fast and just as basic, but holds better. And the FB involves tying a simple overhand knot and then wrapping as in Hedden. Holds better than the Hedden and so better than the Kleimheist and adjusts more easily than either of them. rgold
From Poughkeepsie, NY
Joined Feb 15, 2008
549 points
Jan 11, 2013
i'd avoid using dyn/spectra for anything involving friction (unless you're in a bind--then i'd consider chucking it)....i scored some "technora" off a guy in vegas....essentially a kevlar-like sheath over nylon core....can't burn/melt the sheath, strength of nylon core--perfect prussik material! coppolillo
Joined Sep 9, 2009
75 points
Jun 6, 2016
The klemheist is advantageous for uni-directional travel. Two initial examples might be:

1) Travel on a fixed line where the rapid removal of the sling in necessary to re-affix it beyond a hard knot/bolt, such as fixed lines/j-lines on 4th class traversing terrain.

2) In a rescue situation as some sort of progress capture, such as a ratchet on your haul system if managing a site from above, or as a progress capture hitch if ascending a rope for a counter-balanced ascent to a stuck climber when used in tandem with the gri-gri.

That said, I think dyneems and spectra are horrible materials to use for these applications because of both their static nature (read:low-elongation), and for their low heat tolerance (read:they melt easier). I use either nylon or cordelette for and klemheist I might tie. Sometimes I'll use hollow-block, but it tends to bind up, as mentioned above. Hollow block however does make a great third-hand for rappelling.
Kevin Shon
Joined May 18, 2009
72 points
Jun 6, 2016
Jesse Davidson wrote:
I carry little 7mm prusik slings when I'm on multipitch just in case I need em for something. I use 24" mammut dyneema extendos, and was wondering if anyone has any experience trying to prusik with these things so maybe I can forgo that one extra thing on my harness.



Again - prussiking with a material that has low tolerance to elongation and heat means that any significant dynamic load nearing a factor 2 fall, or one that absorbs much heat of any kind might melt your dyneema/spectra. Now, is it going to just melt apart as you ascend? NO, of course not - but IMHO, nylon is superior.
Kevin Shon
Joined May 18, 2009
72 points


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