Just bought a mammut 6mm rappel cord to replace my old 10.5mm climbing rope it's 60meters long , what's the thoughts on dividing it into two to share the wheight between the group or keep it whole ?
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Obviously A snowHead isn't a real person
@Sako85, not an answer but some thoughts.
There needs to be a couple of ropes in a party.
Although 30m is common for a ski rope in my direct experience for a decent ab or even a crevasse rescue it’s a bit short.
I’m sure it passes all the tests but I’d find 6mm a bit thin and I’m not sure if my various toys/tools would work with it.
For a specific project where a long ab over easy angled ground is required it would be very handy paired with another one.
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If you cut it you will have to remember which half to pull to retrieve your abseil, which won't be easy as both halves will be the same colour. There are ways around this (tow a karabiner down the side you need to pull while abseiling), but abseiling is complex and prone to going wrong, so it may be better to keep it simple.
Edelrid sell two 6mm x 30m abseil lines in different colours, but obviously that's not much help to you now.
A 60m abseil line is a nice simple solution - just get your mate to carry your water bottle.
@Sako85, all depends if you are ever likely to need 60m (ie paired with another 60), or if 30m lengths will be enough... (sorry if that is an obvious answer...).
For what its worth I have been using Petzl's Rad line for a couple of years and it works fine (for its intended purposes) - it comes as 30m standard (think they do other lengths too now). As jbob mentions above definiteyl worth checking compatibility of any devices you are going to use, and also worth sussing out whether you need any extra friction for abseiling (ideally in a not too perilous situation...).
Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
Thanks for the advise I will keep it whole as a knot will weaken it by upto 50%.I bought the rappel kit ,rope,stuff bag ,karabiner and nano 8 £96 from bergziet u.k not sure if my petzel micro traction will work with it though
I think that's a good call. A knot up the top could easily catch when you try to pull it through, assuming you remember to do as described. And assuming you have a knot in the bottom you've already used up a fair bit of line.
Google tells me that you can do a little better than 50% with what you're likely to use (double fishermans with half hitches):
http://caves.org/section/vertical/nh/50/knotrope-hold.html
...but you're unlikely to be shock loading it, I'd say, so that's probably not hugely significant. I'd be more worried about abrasion etc..
There's bog-all chance of me snowboarding with ropes though, I'm just waiting for the snow to fall.
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@Sako85,
Quote:
not sure if my petzel micro traction will work with it though
Petzl's own RAD crevasse kit uses a micro traxion with 6mm cord, so although not really designed for rope that thin Petzl actually supply it for use with that size
www.petzl.com/US/en/Sport/Ropes/RAD-SYSTEM
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After all it is free
@geoffers, a note of caution on that though, Petzl quite clearly state that they have only validated the micro-traxion for use with the Rad line and cannot guarantee its compatibility with other cords of similar diameter. Caveat emptor (or 'skier emptor' really).
@Sako85
re knots - yes it will take ~%50 off the strength of the rope, however a 6mm cord complying with EN564 (eg rad line) must have a minimum static strength of 7,2kN - halve that and you still have 3,6kN (ie ~360Kg) - for ski mountaineering usage this is more than enough - check the cord you have to see if it is EN564 compliant (should be marked on the rope ends)...,
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probably goes without saying but people abseil on two knotted ropes all the time. In general the anchor is what you worry about when abseiling rather than the rope strength because you are not shock loading it.
@offpisteskiing,
what do you carry for skitouring in glacier terrain - with and without clients?
After a recent trip when I had too much weight I've bought a 35m light weight (dynamic) half rope which has a strength rating to be used as a single rope (my thinking is that would be useful for belaying on the odd short pitch not to use routinely). I'm conscious that a big crevasse would mean I didn't have enough rope and would be relying on the heli.
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Oh - I also bought some thinner cord to make up new prussiks - felt the ones I'd used with a 10mm rope might be too thick to get good grip on a thinner rope.
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As the discussion seems to be drifting towards the use of lightweight ropes on glaciers some might find this article interesting...
And love to help out and answer questions and of course, read each other's snow reports.
And love to help out and answer questions and of course, read each other's snow reports.
If anyone wants a fairly light weight dynamic rope (still a big weight penalty over 6mm though) I have found the Beal Ice Line 8.1mm climbing rope to be great for winter use.
So if you're just off somewhere snowy come back and post a snow report of your own and we'll all love you very much
So if you're just off somewhere snowy come back and post a snow report of your own and we'll all love you very much
@jedster, I don't ski tour on glaciated terrain with clients as I am not IFMGA certified...
For my own ski mountaineering I have been on 30m Rad Line for the last 2 years unless I know I need a longer rope or am going to be doing any actual roped climbing.
You know it makes sense.
You know it makes sense.
Oceanic wrote:
... the use of lightweight ropes on glaciers some might find this article interesting...
It was. To summarize: falls into crevasses are easier to hold with static rope because it doesn't bounce.
That's slightly counter intuitive, but they tested it. These falls have very low fall factors - the rope is reasonably taught all the time. The lip provides some cushioning. The faller feels a greater "shock" with static but it's not that much greater and it's no where near the capacity of the rope.
Static's also better for descent.... Presumably the limitation is that you don't want to actually climb on static.
Otherwise you'll just go on seeing the one name:
Otherwise you'll just go on seeing the one name:
Some things to think about.
Dynamic v static. Static ropes should only be used where there is no chance of a dynamic load, even a small fall on a static rope is potentially very dangerous.
Diameter, modern ropes are thinner and lighter than ever. Rather than focus on actual diameter it’s the strength of the rope that matters. Very thin ropes are harder to handle and hard to climb hand over hand, harder to knot securely, and don’t like being bent to a small radius plus tricker to prussic up except with a mechanical device.
Length, obviously longer ropes are heavier, but in many situations a 30m is too short. On glaciers skiing roped with two skiers it will be ok as it will be for a confidence rope over a short step. For crevasse rescue for a shallow casualty in a small crevasse it will work, but for a deeper rescue where a belay has to be set up well away from the edge and a more complex pulley system is required then 30m will be too short but may be useful for securing the victim while help arrives. For abs a doubled 30m rope isn’t going to get you far.
If you know exactly what you’re going to need the rope for, then the type and length of rope should be obvious, however for a “just in case” rope that you have no intention of using except in an emergency then it’s a fine judgment. I have a 40m 8mm dynamic rope.
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@Sako85, I take it the key issue for you is weight? If the 6mm is an ab rope, then presumably you will have a harness, abseil device, carabiners and prussiks (maybe an ascender of some sort?). So a fair bit of weight in total. Are you considering the total weight, minimising the weight of each piece of gear?
Btw, what abseil device will you use with the 6mm rope? One way or another it will be slick and maybe tricky to hold in cold wet conditions unless you have added extra friction by some means??
Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
Sako85 wrote:
Just bought a mammut 6mm rappel cord to replace my old 10.5mm climbing rope it's 60meters long , what's the thoughts on dividing it into two to share the wheight between the group or keep it whole ?
I don't know of any reliable rappel device that would work with a 6mm rope. Most normal belay/rappel plates are good down to 8.5mm, for thinner ropes eg beal iceline 8.1mm many climber prefers a device specifically designed for thinner ropes (eg DMM Bug/Bugette). In a skiing application ropes may be icy making them even more slick. For crevasse rescue a very thin rope is even more likely to cut into the edge of the crevasse and get jammed.
I wouldn't go any thinner than 8mm, also I would go longer than 30m.
Short lengts of 6mm cord can be useful for setting up belays, ag abalokov threads
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On the rocks wrote:
I don't know of any reliable rappel device that would work with a 6mm rope.
You might also be interested to read the article I linked to above about using a 6mm Petzl Rad Line for arresting crevasse falls.
Thanks for the info Oceanic.
Make sure you read these links if you’re intending to use a 6mm rope as there are a lot of exceptions. For instance it’s not easy to set up a safe ab on a single 6mm rope!
Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
That petzl report is interesting, particularly vs what I see as standard practice amongst guides in chamonix. Common practice is 2-3m of loose coils in the hand in the hope (I think) that it buys a second to react, at the cost of a greater force on a dynamic line. Very very few people that I see roped on glaciated terrain have bothered to tie knots every couple of metres (as the Petzl diagram shows) I guess because of the hassle of undoing them every time to need to use the rope for climbing.
If a tight rope with knots really is safer (as I was taught) it's surprising how few people use it. Maybe a thin cord (that cuts into the crevasse lip) with knots to arrest it, static, and held tight, could materially improve safety.
That petzl report is interesting, particularly vs what I see as standard practice amongst guides in chamonix. Common practice is 2-3m of loose coils in the hand in the hope
oh those chamoniks guides eh, crazy fellow !
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Then you can post your own questions or snow reports...
@davidof, nice photos.
I like the coils and no knots myself. I can’t see how you could use a knotted rope through a pulley system or with a prussik so self rescue from a crevasse could be a problem.
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jbob wrote:
@davidof, nice photos.
I like the coils and no knots myself. I can’t see how you could use a knotted rope through a pulley system or with a prussik so self rescue from a crevasse could be a problem.
You don't need many knots in the rope, as illustrated in this video (Produced by Chamonix guides )
If you need to prusik up a rope it is fairly simple to pass the knots, just clip a sling into each knot and stand in it, as if you were aid climbing. Use a cows tail to protect yourself while you move your prusik loops past the knot.
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@Oceanic, thanks for the video, it’s quite convincing.
The pig rig is more or less how I would set up a haul, but the second belay would be a luxury in a real life situation and still you might need to pass the prussiks over one of the knots, also with a 100kg hanging on the rope every thing is more difficult. But with the suggested spacing 3, 2 and 2 if the belay was 7 m back from the lip of the crevasse then it wouldn’t be an issue.
I really like the idea of lessening the impact on the belayer and I also like the idea of being able to clip a sling quickly straight into the rope above you after a fall, so I think I’ll be using knots in future.
One thing did strike me from the video, that was how much a rope might cut into the snow which would make things difficult.
I won’t be getting one of the Mammut pulley devices.
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On the rocks wrote:
Sako85 wrote:
Just bought a mammut 6mm rappel cord to replace my old 10.5mm climbing rope it's 60meters long , what's the thoughts on dividing it into two to share the wheight between the group or keep it whole ?
I don't know of any reliable rappel device that would work with a 6mm rope. Most normal belay/rappel plates are good down to 8.5mm, for thinner ropes eg beal iceline 8.1mm many climber prefers a device specifically designed for thinner ropes (eg DMM Bug/Bugette). In a skiing application ropes may be icy making them even more slick. For crevasse rescue a very thin rope is even more likely to cut into the edge of the crevasse and get jammed.
I wouldn't go any thinner than 8mm, also I would go longer than 30m.
Short lengts of 6mm cord can be useful for setting up belays, ag abalokov threads
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I have the mammut nano 8 rappel device which is fine for double 6mm but I haven't tried it with a single rope yet but there's added friction bit on the side for that purpose.
Weight is always an issue for me , a harness, ice screws,6 x karabiners,petzel micro traction, prussiks , ice axe and crampons it all adds up and rope is one thing I can make a saving on.
My old rope 10.5mm x30m was too short (got caught out on a cliff in Revelstoke ) 60m gives more scope for that sort of thing and for setting up z pullies
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And love to help out and answer questions and of course, read each other's snow reports.
jbob wrote:
the second belay would be a luxury in a real life situation and still you might need to pass the prussiks over one of the knots,
You can put the pig rig and the main rope on the same belay. Ultimately it is more complicated that hauling without knots in the rope, but then, it is less complicated than you and your partner ending up at the bottom of the same crevasse.
jbob wrote:
I also like the idea of being able to clip a sling quickly straight into the rope above you after a fall.
Unfortunately, when the rope arrests your fall the knots stretch tight, and the first knot ends up way out of reach.
So if you're just off somewhere snowy come back and post a snow report of your own and we'll all love you very much
So if you're just off somewhere snowy come back and post a snow report of your own and we'll all love you very much
Reanimating this thread to ask a quick question. Petzl technical notes recommends a 5mm prusik or thinner for use with the rad line. Does a 5mm prusik actually work and for what applications? I would usually use prusiks both in construction of a z pulley and also when abseiling. In the first instance I can substitute a prusik for a tibloc. Second instance really requires a prusik.
For those of you successfully using prusiks with the rad line, what make of cord are you using?
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