Using a half (double) rope for mountaineering

[khu]

I was wondering if it's ok to use a 50m half, not twin, rope for glacier travel. From what I've read, each strand of a half is tested individually, unlike twins (both must be clipped through the protection points). I would assume they are fine since mountaineering loads are much lower than rock (peak forces for crevasse falls range from 3.5KN-7.5KN typical from tests).

 

The rope I have was given to me by a friend. He bought it two years ago as a means to escape his second story condo in case of a fire and it has been sitting in a closet since day 1. It looks brand new. He has since moved to a single story house...

 

It's Mammut and is rated for 6 factor 2 falls, i believe.

 

So you can imagine I'd like this "free" route to work, rather than drop the dough on another rope.

 

 

Thanks!

[genepires]

that is the perfect rope for glacier travel. (the 50m half rope part, not sure if the mammut is the best rope) I assume that it is dry treated. if not, then it is not a good glacier rope.

 

a twin would be fine too.

 

what an interesting way to get a rope. Was your friend uber paranoid?

[DPS]

A half rope is perfectly fine for glacier travel. I use a 50 m, 8.5 mm Sharp rated half rope for moderate alpine routes as well as standard glacier travel. Many folks use a 'rando' rope, a 30 meter half rope for glacier travel.

[khu]

What's wrong with Mammut ropes? I've been rock climbing on them forever and love them.

 

The pattern on mine matches the 8.5 Genesis half, which has the coatingFinish, so it seems to be a perfect glacier rope.

 

Please help me understand this though, I read in the standards that half ropes are tested single strand (and assume a small amount of energy is absorbed by the second strand when falling past protection), but double ropes are tested together.

 

I just want to make sure using a SINGLE half rope is ok, not in a twin formation. On Mammut's site they show single strand clocking in at 15-16 falls (crazy for 8.5mm!).

 

I'm curious why they they state this for their 8.3 glacier rope:

 

"N.B.: Under no circumstances to be used as a Single Rope for mountaineering or rockclimbing!"

 

here's the link: 8.3 Glacier Line - Half and Twin Ropes

 

Thanks!

[genepires]

no jab meant towards the mammut rope. I just thought my wording was implying that I thought mammut ropes were the best for glacier ropes when what I meant was that any double 50m was the best for glacier ropes. I have never owned a mammut rope but I am sure that they are great ropes as most of their stuff is great stuff.

 

they prolly don't want their glacier ropes (or any double/twin line) used as a single for the reason that those ropes are more prone to being cut over an edge. Hence the need for two strands. There are very little cutting edges on a glacier and the forces are considerably less, so you can get away with using it in a single fashion. This is true for all rope manufacturers.

 

 

[DPS]

Just to add to what Gene said, the forces generated in a crevasse fall are much smaller than in a lead fall on technical terrain. Also, there is also a liability issue. Half ropes are rated by the UIAA for use in pairs. If Mammut suggested otherwise they could be liable if an accident occurred due to rope failure.

 

That said, many climbers use a single strand of half rope for technical climbing. Steve House and Vince Anderson used a single 50 m, 8 mm half rope for their ascent of the Rupal Face on Nanga Parbat. A lot of other climbers will bring only a single half with the idea that if the terrain becomes too difficult they can fold it in half and use it as doubles. Many of the steep mountaineering routes around these parts (Liberty Ridge, NR Baker, Coleman Headwall Baker, Adams Glacier) are not that steep so any fall will likely be a sliding fall and since they are ice/snow routes the rope is not likely to be cut.

 

I personally climb on Edelweiss 'Sharp' rated half ropes. These are claimed by the manufacturer to have greater cut resistance over a sharp edge. Marketing hype perhaps, but I still feel better when using a single strand on rock.

Edited August 12, 2013 by DPS

[khu]

no jab meant towards the mammut rope. I just thought my wording was implying that I thought mammut ropes were the best for glacier ropes when what I meant was that any double 50m was the best for glacier ropes.

 

Ah, I see.

 

 

 

Thanks for clearing up the question guys.

[ivan]

Fake Ivan here.

 

Moving to a smaller dia rope may affect your emergency ascension system. Tiblocs are rated for 8 - 11mm, for example. I've gotten them to work on a 7.8, but never actually used them for real on one. Best to test this at home.

 

I can tell you that a 5.5mm prusik doesn't work at all on a doubled 7mm rap rope. It's nearly impossible to move the knot up once tightened. This was testing trying to get out of a schrund. I finally just had to free the damn thing.

Edited August 12, 2013 by ivan

[genepires]

Fake Ivan here.

 

I can tell you that a 5.5mm prusik doesn't work at all on a doubled 7mm rap rope. It's nearly impossible to move the knot up once tightened.

 

try using a bachmann hitch next time.

[chris]

FWIW, I've had no problems using 5mm cord and dyneema slings as autoblocks and kleimheists on 7.8mm ropes.