UKC

I've done a reasonable amount of glacier travel, often with teams of 4+, but will be doing some climbs soon where it will likely be just me and one other. We're fairly similar in weight and I'm confident in our ability, but I'm always a fan of stacking the odds in your favour.

With that in mind on the various glacier sections we'll be crossing I'm was planning on employing the age old, proven method, of tying knots between the climbers to help arrest a fall. I'm wondering though if it's something that could be improved on (if I'm being an idiot by all means tell me, I'm sure many here have more experience than me).

Basically my thought is the possibility of using lightweight snap-gate carabiners instead of just plain knots. To me there seems to be various possible benefits. Firstly it takes up less rope than an overhand knot on the bite. Secondly all the knots tightening onto the carabiners along the length of the rope will potentially help absorb some of the shock of the fall. Thirdly it means if the fallen climber intends to climb out the crevasse themselves there are already evenly spaced carabiners to grab/clip slings to to aid the climb out. And finally if a haul system is necessary, one of the main nuisances of a knotted rope is bypassing the knots; if using smooth nosed carabiners tied in with a clove-hitch for instance than it's a simple matter of slipping the carabiner out to untie the knot instead of having to fiddle to bypass it (although admittedly with a minor drop experienced by the fallen climber).

So, thoughts? Am I just being a completely idiotic, inexperienced danger to the community, or is it a viable idea?

In reply to Dheorl:

Which knot do you intend to use to attach the biners? (clove hitch I presume)

Why do you think this will absorb more force tightening than overhands?

Do you think you'd be able to slip a biner out of a loaded clove hitch? I have my doubts.

In reply to CurlyStevo:


especially this

In reply to CurlyStevo:

In my experience a clove-hitch at rest on a biner normally sits with more slack in it than an overhand, but the difference here is negligible, so I guess this isn't so much a benefit vs using plain knots as just a benefit vs doing nothing.

As for slipping the biner out trying it briefly I don't have huge issue with it, certainly less faff than working the pulley system around the knot. I was using DMM alphas, but I imagine harder with other biners, will try it later.

I guess you're not much of a fan of the idea then?

In reply to Dheorl:

I think you'd find all the loose clove hitches a bit of a mess and they might loosen to the extent that you've got various large loops of rope hanging from various biners. You could try to keep the rope in a bit of tension but that can't be 100% of the time as you'll always stop fairly reguarly.

If you do then weight the rope in a crtevasse fall those loose clove hitches and rope loops will weight your karabiners in some very unpredictable ways, possibly opening the gates, cross loading them, causing knots in the loose loops.

I can see were you're coming from with the idea but lots of loose clove hitches are not going to work really.

In reply to Dheorl:

I personally think an overhand tightening would absorb more force but as you say not of much consequence to the idea.

Did you try slipping the biner out under body weight?

In reply to Dheorl:

The slipping a biner out of your rope whilst it's under weight is almost a moot point. If your partner is in a slot, it is damned difficult to set anchors in the first place, let alone escape the system, set up a pulley system and haul the other person out. If you are on snow rather than bare ice it's even harder. Really as a two, if your partner is in a slot and uncontious you really do have a problem unless there's help around! If they're contious, whether you have a knot or a biner is also a moot point as they will clip their slings into the knot/biner to stand in it to climb out. Pretty much the only time a pulley system will work is when you have an anchor man who is uphill or slightly downhill of the crevassee (not too much friction over the edge, backed up by a second person who can scamper around making everybody else safe. So the upshot is work on avoiding crevasses at all costs!

In reply to yesbutnobutyesbut:

This is a fair point. With the clove hitches fairly tight they stay in place and load predictably under shock, but obviously keeping them this way isn't always feasible and it reduces the slippage to absorb a fall.

Having sat shock loading lose clove hitches on biners (I know, what an exhilarating life I lead ) around 50% of the time they were less than ideal.

In reply to CurlyStevo:

Yep, under body weight I could fairly reliably slip the biner out. If however as someone else mentioned it worked loose and the knot tightened in a less than ideal way it suddenly became a lot harder.

In reply to Dheorl:

I wonder if the knots would be tighter if the systems was shock loaded in a similar way to a crevasse fall.

In reply to beardy mike:

I've personally managed to go from an arrest position with a body hanging on me to a anchor with no external help. It was admittedly a training exercise, but I found it doable. Conditions were a few inches of well consolidated snow on top of glacier ice. I've never had to do a rescue irl because whenever someone has gone through a snow bridge they've always stopped either at waist height or shoulder height (and I've spoken to life-long mountain guides who have had similar experiences) but the amount it's talked about online I figure we've all just been very lucky for years so I'll stay prepared. And no matter how unlikely it is, if I do have to set up a pulley, by myself or with help, I'd always want to make it as easy as possible.

The routes we'll be travelling on are fairly well travelled, so help is likely to be available, but I would have said it was pretty much a given we'd be avoiding crevasses if possible.

In reply to Dheorl:

every time a knot that is loose tightens, should one of you fall in, it adds distance to how far in the hole they go.

Zero knots, not too much rope out, rope pretty tight & bouncing off the ground with good communication & observation between you.

In reply to CurlyStevo:

Would likely be slightly harder, but I was giving the rope a fair old bounce, and if somehow my partner had fallen hard enough to shock load it in a big way I've done something wrong and am unlikely to be stopping that fall either way.

As I say, I probably have a good biner for it, something with a more hooked nose would likely be harder.

In reply to summo:

I personally always keep my rope tight enough it's well off the ground; I like to keep it dry

Why does every resource I can find online say knot the rope with a party of two then? There seems to be fair practical trial to back it up.

In reply to Dheorl:



That's my experience as well, keep the slack out of the rope and they're not hard to hold at all. If you do use knots then I would make sure you each have enough spare rope to reach the other climber, either in coils or another rope. That way when your knotted rope becomes hopelessly jammed you can use the spare/other rope for the rescue.

In reply to Dheorl:
Instead of clove hitch, marlin spike hitch might work better, less rope used than a clove and would be easier to slip out.

Using DMM XSRE's would keep the weight down as they're about 10g each, (but obviously you can't climb/haul on them)

In reply to Dheorl:

It's interesting in a geeky kind of way whether or not you could slip a carabiner our of a loaded clove hitch, but I would say the more important issues are 1) Does the carabiner actually help the rope stop at the lip or a crevasse (which is the whole point of knots), and 2) How much extra faff and time do the caraboners add when coiling rope, changing rope length, and so on. It might me more trouble than it's worth. Perhaps it would be easier to just use Butterfly knots? I'm not sure the added benefit of having the carabiners for hauling is worth it because...

Regarding how to haul past knots, the solution is to haul on another strand, with a dropped loop, or a dropped knot, or different variations thereof. This approach has many advantages, and only one disadvantage, which is that each climber must have enough rope in coils around their shoulders to create a hauling system, which is usually not a problem if your crossing a glacier with a 50 or 60 meter climbing rope, but might be a problem if you are just using a 30 meter glacier rope. Even then, unless you are really spread out, you will both probably have enough. These techniques are explained well in Mark and Kathy Casley's excellent book, Alpine climbing. I have practiced and and taught them several times, and I am a a big fan. Knots on the main rope and hauling on a second strand is my go-to system for two person travel.

Regarding whether or not to use knots at all, they do seem to work well, that is, they do help catch the rope at the edge of crevasses. I've only seen this in practice situations, but it has been communicated to me a a very effective method by several experienced guides that I trust. Why not stack the odds in your favor?

About rope length, a little sag in the rope so that it touches/drags on the snow with no slack or build up but also with no tension is appropriate. If it's completely off the snow it's probably too tight. Length determined by conditions. And communication and smooth teamwork are of course important too.

Be safe and have fun!

In reply to brunoschull:

+1

Another consideration of clove hitches is that they will put a prominent wear point on the rope.

Far better to have an overhand, alpine butterfly for the pedantic or unknotted rope for wear considerations.

In reply to brunoschull:

I've always assumed the reason a knot helps is it's like a mini deadman, and as anyone who's abseiled off a chocolate bar knows any solid object makes for a fine deadman so I'd assume a biner would have a similar effect, especially with the knot of rope on it. The biners are just as quick and easy to slip in and out as a bunch of overhand knots are.

The notion of hauling someone up via a dropped loop has always baffled me with two people. Sure, with a larger party it makes for a very easy pulley system and something I've personally taught, but with a party of two, as mentioned by someone else, the easiest solution is for a conscious climber to haul themselves out. If they're unconscious then you're going to be doing a surface based pulley either way, in which case I would have thought quickly popping approaching biners out would be handy. I've heard of people walking with two lengths of rope between them, one knotted and tight and the other looser and free of knots and this seems like another possible solution if you have the rope (apologies if this it what you meant, but I understood it as still only one strand connecting you and the rest in coils). Would also make getting the weight off your body onto an anchor easier. Does seem like quite a bit of faff though.

As mentioned, I personally like keeping the rope up off the snow, and have never had issue with there being too much tension. If you prefer it looser I guess that's personal preference, but I can't see any downside to slightly less slack. And of course I'm going to stack the odds in my favour, hence the entire point of this thread...

In reply to Dheorl:

Sounds good. I can understand your reasoning. There are so many different methods--I think the more important thing is to just have some kind of plan that you can adapt to circumstances.

Why don't you test the knots/carabiners with a loaded road? You could arrange something at a climbing gym or crag. You could also test the "stopper effect" of a rope with knots vs a rope with knots/carabiners by sawing a rope back and forth over some snowy/icy edge. You would surely gain enough information to make a decision for yourself.

About the dropped loop, here's my approach, as a rough summary. I think it works well for two person teams. Arrest fall, build bomber anchor, ice screws, dead man, whatever, transfer loaded rope to anchor, hopefully first with a prussik pre-rigged to rope, and then with a secure knot. OK, that's done, climber is safe. If the climber can not ascend on their own, I would carefully flake out the extra rope around my shoulder, and approach the crevasse, perhaps with some security, depending on conditions. Let's say I decide to haul, and find a good place. One cool thing about hauling with a dropped loop is that you can really prepare the lip, and decide exactly where to be, leaving the weighted rope in place, which reduces friction, and therefore reduces the (high) forces on the anchor, and the hauling forces, and keeps everything safe. So lip prepared, then what? On the unweighted rope coming from the anchor back to me, I would tie some kind of knot, like an overhand or figure eight on a bight, at at appropriate place, perhaps close enough to the lip that I could watch the climber as I hauled, which is another cool thing about this system. That knot would become my new master point. Then I would drop the loop with a carabiner to the climber, or rap down and clip it myself to the climber's harness. Back to the new master point. I like to use some kind of rope capture device there; my favorite is the popular Kong duck. I pass the rope through that, and therefore have a ratchet. On the strand going into and coming out of the ratchet, you can add as much additional traction points, pulleys, and so forth that you want, to get the mechanical advantage that you need. I have always added just a single prussik to change direction, and then hauled by walking away from the crevasse. The ratchet holds the rope, you have to walk back to re-position the prussik.

Of course, there are endless variations and alternatives, and hardware that you can add or remove, but that's one system that works well. What I like about it is that 1) you can easily use knots on the rope between climbers, 2) you can leave the main rope on the anchor at all times, 3) you don't have to worry about switching the attachment of the main rope to the anchor from a fixed knot to a hauling system, or adding a hauling system at the same place, instead, you can build your hauling system on a new master point, hopefully closer to the crevasse, where you can see/communicate/prepare lip, and so on, 4) I think being able to really set up a good place to haul allows you to reduce friction, and thus force on the anchor and force needed to haul, and so on. Probably other advantages too, that I am forgetting. The disadvantages are the length of rope required (not as much as one would expect), and the necessity to get the loop or line clipped to the climber. Pros and cons with everything. Anyway, that's my system.

If you experiment with the knots and carabiners, let us know.

All best, Bruno

In reply to Dheorl:

Personally I think that you are over complicating the situation. A perfectly satisfactory, proven method already exists. I would pay more attention to extracting an unconscious climber already in the crevasse, this is far harder than people think.

Al

In reply to brunoschull:

Thanks for the explanation. Not how I'd personally do it, but interesting to hear other peoples methods. When I say it baffles me, I understand the principle, I've taught plenty of other people myself, I just would never personally put it into practise with a two man rope team and unconscious casualty. Unless you're building a second anchor for your second master point then I'd personally rather do the best with whatever edge (modified if necessary) I have and be sitting on the anchor than moving to get closer to the crevasse. The thought of abseiling down to attach a second rope isn't something I'd consider as anything other than a last measure.

If I've got a friend unconscious down a crevasse then I'm planting an anchor with the most basic pulley system I can manage with, going straight from rope on prussic to rope on microtraction, sitting on it and hauling ass. Sure, probably less efficient, but it's how I'd do it. I guess everyone has different ways of working in such an environment and it's best to do what you're comfortable with. The carabiner idea is simply to try and make my approach simpler. I tried them loaded in my garden and can pull the biners out without much issue, the only problem is the awkward knots you get if a loose one is shock loaded.

From reactions here I might just adopt the method of moving with two lengths of rope between climbers, one knotted and one bare, but if I get enough time to play around in the snow to experiment more with my idea I'll be sure to post results here.

In reply to GridNorth:

The problem is I'm trained as a scientist, engineer and am recently moving into product design. My brain hears the word "satisfactory" and instantly wants to go to work.

I understand it's not an easy thing to do, I've practised and taught it many times with lard asses who are very good at playing dead, although never had to use it because as I say, I've never known a climber go in above shoulder height.

In reply to summo:


Theoretically true, but not really relevant. 10 to 20 m of rope between the climbers, adjusted continuously depending on terrain gives you at max something like six knots.

The benefit of having a good chance that one of the knots catches as the rope cut into the crevasse lip by far outweighs the risk of falling half a meter further. In addition, even if the knot takes only part of the load, it will make building an anchor much easier.


IME, short roping is good for catching slips, but near useless for holding crevasse falls. On a crevassed glacier, spread it out, on steeper steps take in some rope. Your other points make much more sense.

CB

In reply to Dheorl:

Obviously it very much depends on the route / objective and conditions. When I judge knots on the rope are required on the way to or from a more technical route I would normally have a second half rope in a rucksack, usually the person at the back has it. ( Not fool proof I know ). So this becomes available for use once the fall has been stopped and an anchor set up.
If I judged that knots in the rope were needed and I was on an easier route only requiring one rope but in an area where there are very few people about I would often carry a second lightweight rope anyway. I have rarely had to do this in the alps but have done in New Zealand and Nepal.