Sean_T_Stevenson

Using knots at all is a judgement call based on the snow and ice conditions. The theory is that the rope will cut a slot in the crevasse lip during a fall, and the knots will jam and arrest, or at least add significant friction so that your rope team can arrest. In either case, you won't be hauled out on a knotted rope, so must either self-rescue or have an additional line lowered. If you choose to self-rescue on the knotted line, then as you suggested you can just retie your prusiks around each knot - slow, but it will get you there. Such a situation is made easier with ascenders since they clip on and off quickly, but it's the same idea. Alternatively, if you have enough rope to tie closely spaced knots and don't mind the weight, you can put butterfly knots in with large enough loops to use as footholds, and simply climb those, tying-in short at each loop passed (or clip your prusik slings to the knots with carabiners). Of course, for this to work you need knots only an arm-length apart, so this may be impractical. In general, the choice to use knots comes down to the expected ability of the team to hold a fall - if successful team arrest on a clear line is unlikely, then knot it. Either way, hauling on the same rope you fell on is likely to be extremely difficult - hence the recommendation to carry coils, so the topside team has enough clear rope to effect the rescue. If the fallen climber can establish a secure anchor in the crevasse wall (ice screws, etc.), then you can unload the rope and set up a proper system at your leisure. If you can stem the crevasse, you can use the knotted rope as a belay by clipping successive knots into an anchor as the fallen climber free climbs out, or use a hip belay as mentioned by another poster, but I would only do this if the climb out was easy and a failed move was very unlikely. The upper knot on both of the Texas prusik slings I use on every glacier climb is adjusted to the correct distance so that if I tie them on to the rope as prusiks, or clip into ascenders at the knot, the effective length is the same. Ascenders are heavy to carry if you don't need them elsewhere on the route, but a great tool to use in a crevasse if you have them on you anyway.

Great jacket. Shame it isn't an XL.

I always carry Texas prusik slings - i.e. a set of foot loops and a waist / chest loop (attached to waist and possibly clipped into chest harness after fall), for crevasse extrication. If I happen to have ascenders on me (if there is fixed-rope climbing elsewhere on the route, or aid sections), I will clip those loops into the ascenders instead of doing the prusik wraps because it's faster, but the concept is the same. The upper ascender / loop extends to just before the limit of my reach when hanging from it, then when I bring my legs up as high as possible, the foot ascender / prusik slides up to just beneath the upper one. Then I stand, push up the waist / chest ascender, and repeat. It helps to remove my pack and clip it into the rope bight between the foot ascender and the harness tie-in, so that it is weighted and advancing the foot loops doesn't move the rope around much. Periodically I may tie in short to reduce the fall distance should an ascender fail - depends on the distance to top out.

PM sent.

I think an important consideration would be to carry, at minimum, sufficient gear to effect a rescue by yourself in consideration of the possibility that every other member is in the hole. This doesn't mean you need the best possible bomber anchors, pulleys and so forth, but rather that you, if pushed under this exceptional circumstance, can improvise a plan using the gear you have available (burying axes or packs, using double biners in place of a pulley, etc.) Additionally, you must also carry sufficient gear to effect a self-rescue should you fall in the hole, but the same ethos applies. Once your absolute minimum gear is determined, what you choose to add becomes a tradeoff between carried weight and ease of use / speed of rescue, and in the case of protection, will also be dictated by the snow / ice conditions expected. No one set of gear will be appropriate to every situation. Accordingly, I will carry only an axe and a set of Texas-prusik slings for one objective, and 2 pickets, a fluke, 2 pulleys and a pair of etriers and ascenders for another, depending on what I'm doing elsewhere on the route and also how remote / removed in time from medical assistance you are. Saving a few ounces here and there is less important than ensuring a timely response to an unconscious and injured climber, for example. Consider the totality of circumstances, and also consider that how you choose to go about effecting a team or self-rescue is less important than simply getting it done.

Just one additional note / consideration: While I certainly don't want to discourage the mountaineering pursuits of board participants regardless of age, for the purpose of developing maximum team cohesion and social congruency in the limited period of time available, I'm really looking to pull partners from within the 20 to 50 demographic.

Safety & training issues notwithstanding, I don't want to exclude anyone who wishes to come along. I'm hanging on to all of your emails - I still have some Canadian friends who may be able to find time, but it is too early yet to get commitments. We'll put this together as the time approaches. What I would like is a better sense of what dates within the stated window work best for everyone, and also how you all feel about adding some extra time to the time that would otherwise be required to summit, in order to do some skills practice and team familiarization?

The info in the link that chriss posted was telling. I didn't address friction between the rope and the rock at all, and if that exists it is going to be significantly greater than the friction through a carabiner at a point of protection. Also, even if you disregard that, the problem is not really predictable - the linked site shows an example with alternating 160 degree angles - that's about as likely as a straight shot through perfectly placed pro from the belay to the lead so that only the top piece is loaded - that is to say a very small but non-zero probability. An illustrative example, though feel free to place your pro with laser alignment if you want ;-) Getting back to the OP, obviously there is a continuum of possible friction conditions. More friction in the rope system means more energy dissipation there, and consequently more force on the loaded protection. In that case, the theoretical fall factor is greater as explained in the link. However, the additional friction will lessen the braking load on the belayer, which may make it easier to bring a leader fall under control in a dynamic fashion. Exposure permitting, taking some time/distance to arrest a fall lowers the theoretical fall factor due to the increased length of rope. The theoretically ideal situation would be to have the energy of a fall absorbed solely through a combination of rope elongation and controlled belay slack over as great a distance as possible (i.e. brake the rope at a constant acceleration to arrest the fall just before the leader hits the ground), while miraculously managing to distribute the rope loads on all pieces of protection evenly across them in proportion to the strength of the placement. (i.e. your bomber slings are off-route and take much load, while your sketchy screws in rotten ice happen to be perfectly in-line and unloaded). There is so much variability that the problem only really exists as an academic exercise. It does, however, support the idea of spacing your protection placements evenly, versus running out a long way on lead in comparison to the distance between your last couple of placements.

I would just add to the discussion that there are two coefficients of friction in any sliding contact system: the static coefficient, which applies when transitioning from not moving to moving, and the dynamic coefficient, which applies to any sliding system already in motion. Typically, the static coefficient is much larger than the dynamic one. A climber on lead will move rope through the system in small increments - repeatedly having to overcome the static friction as the rope stops and starts. This constitutes the bulk of "rope drag" - the energy required to get the system moving. In a fall, the static friction only needs to be overcome once, and then the lower dynamic value applies until the system comes to rest. Once set in motion, energy dissipation through friction between the rope and protection placements, if the route does not wander or zig-zag, is likely to be small in comparison to the energy dissipated through the belay and the rope deformation as the fall is arrested.

OP talked about the thermometer "bottoming out", so I assumed we were talking about extreme conditions. I don't use the VBLs unless it is really cold - it is certainly more comfortable without them - right up until your liners become damp and/or your sweat carries away too much heat to maintain warm feet. The liner socks I use are thin - with the VBLs, they prevent moisture pooling (VBL directly against skin is not so comfortable) and help wick some of the moisture up and out of your boots (losing some heat in the process, but keeping the insulating sock 100% dry). This also means you don't have a heavy pair of socks to dry in your sleeping bag at night, meaning that the energy it would have taken to dry these can go to drying other items or keeping your body warm. Without the VBL, the liner still performs an important function in shifting some friction away from your skin to between the two sock layers, reducing the incidence of blisters. The overboots are tangential to good boot design, sure, but are necessary in extreme cold conditions unless you wear a singular purpose boot like the Millet Everests or something, in which case you lose versatility. You definitely have a point about simpler being better, though. The less time you waste messing with gear, the faster you can travel.

Not mentioned in the article is that fact that your body is an important part of the boot system. If you are well fed, well hydrated and the rest of you is warm, cold feet are much less likely to be an issue. Conversely, if you are taking in insufficient calories, are dehydrated, and wearing layers which are not quite enough for the conditions, your body is going to respond by reducing blood flow to the extremeties, making your feet cold. That said, I have use the Lowa Civetta GTX Extremes in some ridiculous conditions with no issues, using: 1) liner socks: Wigwam Ultimate Liner Pro 2) vapor barriers: oven roasting bags 3) insulating socks: Thorlos thick cushion mountaineering sock 4) boot liner: stock liner (Intuition Denali is supposed to be even better) 5) boot: Lowa Civetta GTX Extreme 6) overboot: 40 Below Purple Haze Works for me. YMMV.

Planning well in advance due to other real-life scheduling issues... Looking for partners interested in a winter ascent of Mt. Rainier, sometime between December 17 and January 11, via the Ingraham Glacier route (not looking for extreme technical difficulty). I'm in Vancouver, BC, and will be driving down. Age 35, and generally alpine-style / self-sufficient, but NOT "light and fast" (I'm a plodder, and like to sleep comfortable). As for ethics, I have nothing against aiding to get where I'm going. prospective partners to have: avalanche safety training alpine experience (multi-day, etc.) winter experience crevasse rescue training Rainier experience a bonus patience & a good sense of humor Looking for minimum of 2 partners (1 rope team of 3), maximum 7 (2 rope teams of 4). Anyone interested?

I have done this when I want to use all 60m of my single for a double-length rappel, but I'm really only using the skinny for rope retrieval. I use a 5mm cord the same length as my single (60m). I setup the rappel with the joining knot on the small cord side of the anchor. I put an in-line eight knot in the large single just behind the joining knot (still on the recovery cord side) and clip a locker into it, then clip that around the large single rope on the opposite side of the anchor. Then rappel down the single as a single - the knot will jam against the anchor. I weight the recovery line just to minimize the jamming against the knot so it isn't too hard to retrieve, but even if you don't weight it at all, the locker prevents system failure. Worst case scenario - the knot slips through the anchor, basically seizing to the anchor because of the in-line eight / locking carabiner. In that case, you still have a full strength single to ascend to sort it out. Otherwise, pull on the retrieval line, and the whole thing should feed easily.

asking price?

I need help! I'm looking for a boot / binding combination that will work for my US size 15 feet (mondopoint 33), for ski mountaineering. My climbing boots, as far as I can tell, are the only ones available in my size: Lowa Civetta GTX Extreme. I was looking at a binding that might work with these, like the Silvretta 404 or 500, but from what I can tell from searching on the net, neither of these will open far enough to accommodate my Civettas. Disheartened, I resigned myself to carrying two pairs of boots (ski + climbing), and started to look for an AT boot / binding that would work for me, but I can't seem to find a single manufacturer that makes an AT boot larger than 30.5! Am I totally out of luck here?