edelweiss sharp 8.5 mm?

[kinnikinnick]

i'm looking to buy an edelweiss sharp 8.5 mm to use as a single rope for alpine ice and doubled over for simuling/pitching out easy alpine rock with short pitches like forbidden peak. obviously this isn't the safest idea but i'm curious how many of you use this strategy to save weight. thanks

[montypiton]

I've used this tactic since the '80s. I think its fairly common among those of us who use double ropes a lot. Taking only one half-rope, and folding it in half still leaves you the same rappel capacity as a single fat rope. And you usually aren't going to run 60meter pitches on moderate alpine rock. It's a sound idea that has been used for at least a couple of generations.

[mike1]

I too to have the 8.5 sharps and I have doubled one to simul as you describe. I wouldn’t recommend using a single rope for alpine ice though. I use a single for glacier travel, but if you begin entering into the more vertical alpine ice world you should double them. Maybe I am misunderstanding your question...

[mattp]

Like Mr. Piton, perhaps, I have used the single skinny cord for a variety of general mountaineering outings. I have doubled it for leading short pitches of rock both in the Alpine and even in crag settings, too. I used to like the precursor rope, the 9 mm Stratos, better than the 8.5 mm sharp, though. It was stiffer and generally more solid and had a much better sheath.

 

Piton didn't say he's done this but I've used a single 9 mm rope for leading alpine ice, too. I don't know if "standard practice" has changed but it used to be fairly common for climbers to climb alpine ice with a less than a "full" rope. I think the theory was that the leader had no reason to fall - and damn well better not - while the 2nd could be a little more casual about it with a top-rope belay. As far as I know, the 9mm rope was considered more than adequate to catch a leader falling on an alpine ice sheet, though I'm not exactly clear on why that was said to be OK whereas 10mm or 11mm was thought necessary for rock. Maybe because it wasn't as steep so the leader wouldn't fall as hard? Or there are not likely to be sharp edges?

 

 

[keenwesh]

I lead alpine rock on a single half rope, they're designed to hold falls individually, if your alternately clipping them. to be fair, if the route is harder than 5.7 or long I'll take a single or 2 halves, but for most alpine, both ice and rock, a single 50m half works great.

[DPS]

I use this exact rope as a single rope for moderate alpine ice and rock climbs.

[mike1]

I agree with the use of a single strand to a point and I think you guys are defining that point. Something to keep in mind is that even though they say the rope is tested to take 9 falls per strand, they are testing at a lower standard than a single rope. The 8.5mm sharp has an impact force of ~5.4kn (with 80kg (176lbs)), while the Laser Arc 9.6mm, for example, is ~8kn (with 80kg (176 lbs)). Another example: Mammut tests their half ropes for falls with 55kg (121lbs) and their single ropes with 80kg (176lbs).

[Dane]

Couple of thoughts come to mind.

 

First, fall energy is defined by amount of rope in the sysyem. So "hard" or "soft" falls can happen no matter the terrain.

 

"The fall factor is a derived number used to evaluate the shock loads generated on the climber, belayer and anchors that occur when a climber falls. The higher the fall factor, the greater the forces placed on the components of the system. The math is simple:

 

Fall factor = length of fall / length of rope"

 

You need to understand this info when choosing a rope and how you decide to use your climbing system.

 

http://www.southeastclimbing.com/faq/faq_fall_factor.htm#dynamic

 

We all seem to use half ropes or even twins in similar situations to save weight. Same places where we figure a lighter rack is appropriate as well (to save weight) and more than likely the risk of a high fall factor incident (run out "easy" ground) is likely to occur.

 

As Mike pointed out 1/2 ropes are not tested to the same weight loads or impact forces. If the rope doesn't break from being cut (rope damage being the reason dbl ropes were intitially used) the IMPACT force will be important to the climber held on the rope.

 

Something not mentioned yet in the discussion is light impact forces (which you want in a fall) mean a really stretchy rope. In the case of a twin and some of the lighter dbls some *really, really stretchy* rope. Enough stretch that you might just hit something well beyound what you might have thought possible in a fall. BTDT, not so pleasant.

 

I might suggest being really careful where you decide to use ropes not rated for your purpose and accept the fact the leader must not fall. But then if the leader never fell he would not need a rope right? Super stretchy top ropes can be and usually are a really bad idea.

 

DBls through crevassed areas make sense, (easier to get out) as do dbls on some technical rock. That gives you a single strand to run out easier ground or steeper snow and ice....but *are* you going to use enough pro to minimize your fall factor so you don't over load the entire system to failure? I doubt it. Mt Hood comes to mind.

 

We all want to save weight. Hard to do when you are packing 60 and 70 meter ropes or worse yet two of them. I have recently gone back to a single rope in any size for most climbs. Super thin ropes in the 7mm sizes make a lwt dbl rope system when I can get by with only 100' or 110' pitches, which you can on most alpine climbs. But they are dubious as single ropes when you realise everything involved and required of a climbing rope. Ropes like the Beal Joker make good lwt single ropes if you want to climb faster by having fewer belays.

 

Heaven forbid we go backwards but 150' ropes (or less) made the first ascents of everything from El Cap to "modern" hard waterfall climbs. 45 and 50 meter ropes in modern lwt single rope form (like a Joker or its equal) might be a good compromise that you never have to worry about.

 

Lots of very experienced opinions already on this thread. I have done exactly as you are intending for years and as recent as last month. I have over the last two winters been rethinking my own use and no longer suggest using a dbl rope as a single any time outside of simple glacier travel where the likelihood of a severe fall is limited.

 

I wonder how many here using a dbl as a single have fallen on one while in that use? Top rope or lead? If so I would be the first to replace that rope. That makes it a one fall rope and rather expensive. Ropes don't break, they are cut or burn through by contact with another rope. (Dan Osman's was a burn through ) But they do have a service life. Thin ropes obviously have a shorter service life than thicker ropes.

 

Here is a REI speil on twins (they offer a couple of brands) as a short single rope. So many folks thinking along the same lines. This is the rope I am most likely to use on Rainier today but I also know its limitations.

 

The ultimate rope for minimalist mountaineers and backcountry travelers—with a weight-saving 8mm diameter and shorter 30m length.

•Compact size and dynamic construction is suitable for glacier travel and backcountry safety

•Water-repellent sheath reduces moisture absorption and repels dirt

•Not intended for technical climbing

 

NOTE: Twin ropes are designed to be used in matching pairs (sizes, lengths and brands) and should be used parallel within a twin rope system. Using a mis-matched pair will cause undue wear on the ropes, exposing you to a higher risk of rope failure. They can be used singly in certain situations (like basic glacier climbs and traverses) where the risk of severe falls is absent.

 

 

 

[obwan]

I use a PMI Verglas 8.1mm Dry Half/Twin that can be used both as a single or paired. According to Hoyle, there is a determination that a rope marked with a 1/2 at the end tape can only be used as 'paired', rather than singly. Refer to - http://www.rockandice.com/inthemag.php?id=8&type=gearguy

So, there seems to be different specs for the 'Twin' vs. 'Half'.