chris_erickson

A and C would seem fairly obvious, don't you think? When I've seen this occur, my best guess was that dynamic ropes cut in to lips more because the dynamic rope was moving (stretching) substantially more while weighted. The low-stretch events are over much quicker (assuming a solid arrest), and when the weighting of the rope occurs, the event is pretty much over. Thus the rope doesn't "saw" the lip as much. Dynamic ropes keep stretching after the arrest, and as more and more of the load transfers to the anchor/rope, it cuts more. The video posted should be a pretty cool reminder to practice self arresting and practice good rope spacing. I think we may have dragged this down in to the weeds, sorry!

I could be wrong here, but in my anecdotal experience it's the other way around. Dynamic ropes absorb more force than low-stretch ones. So if I have it correct, Dynamic lines = less force on anchor, more force (tension) in line. Low-stretch lines = more force on anchor, less tension in line. Since the dynamic rope absorbs more force, i.e. a higher unit of tension, it cuts more. The decreased diameter of the tensioned dynamic rope, again anecdotal, seems to create a substantial difference in lip cut. My falls on low-stretch ropes seem to cut a long ways, but falls on dynamic lines always cut more.

Great video, however to me the rope spacing is the main issue. I use low-stretch rope exclusively in glaciated terrian (barring an approach to a technical climb) and also train regularly with it. Even novices are able to catch a real fall, downhill, while not looking at the faller if the rope spacing is adequate for them. That said, it's a trade off. Dynamic rope = more stretch, worse cut in to the lip, longer to haul/ascend, greater likelihood of catching a leg/crampon during the fall. Low stretch rope = less stretch, higher force to arrester, less cut in to lip, less distance in a fall. The Denali Ranger/Guide community is a bit split on the subject. Rangers and some guide services use low-strech. Other guides use dynamic. I also use knots in the rope, but perhaps in more specific terrain such as: steep (difficult to arrest), low-friction snow, inexperienced partner, shorter rope, skinning (i.e. ice ax not in hand) and others. Kurt's probably smarter just to use knots all the time. Last thing - I train with real crevasse falls quite often as in the video. Personally, I tie the backup safety line to the faller, not the arrester. In many of the video clips, the arrester's ice ax is quite close to the rope coming under tension. Low likelihood event for sure, but I feel better having the backup line completely out of the way.

My wife and I are leaving PDX pretty early on the morning of the 12th for Bozeman. We are returning pretty early on the morning of the 16th for Portland. If anyone in the area is looking to carpool - shoot me a text. chris five Oh 3; 67Niner, seventy twentyfour

Most Avy 1 classes are one day in the class, one day in the field. Don't underestimate how much you'll learn by attending a level one class. For many, it's worth taking a couple of times. If you live in NW Oregon - check out Mountain Savvy for class offerings.

I don't use toothed devices to catch falls in crevassed terrain, even though the fall factor should never be anywhere even close to 1. -Typical maximum free fall (not rope stretch) in crevasse situation ... 2 meters -Typical minimum rope in service (team size dependent) ... 15 meters -Typical maximum fall factor = 0.1333 -In reality, the peak force is absorbed significantly by a) a non-fixed anchor ... the person catching the fall and b) the rope cutting through the edge of the bridge. Truly hitting a high fall factor in crevasse falls is nearly impossible. You can easily adapt a regular pulley to become a prussik minding one two ways. Everyone knows the ATC trick, but a better one exists by simply cutting a plastic card. - I've written a blog post about it and lots of other pulley considerations for Oregon Mountain Community here: OMC - Pulleys

Welcome to the wonderful life of being a Dynafit owner. I worked in the shop at OMC in Portland and we noticed this too - but our determination was that during a bad wreck it more commonly was the boot that got misaligned, not the binding. A new boot off the wall fit the "busted" bindings perfectly while the old boot was off. Either way - you pretty much have to ski Dynafits in lock-down mode any time you are in consequential terrain ... period. Hate to say it, but nobody wants the G3 Onyx bindings mainly because they don't look as sexy. A tad heavier, but they don't seem to have this problem.

Coverage is fine the entire way up and down the ridge. Soft on N (ish) facing slopes and crusty/firm on S facing.

Not many folks get to see the beauty of the Traleika glacier - good style.

letsroll: it was icy everywhere, every aspect, every elevation. If I did it over again I'd still ski to and from the A-frame, but just know that it's survival skiing. denalidave: I leave in 6 weeks for my 6th season in Denali. 4 on the northside, this will be my second based in Talkeetna. Can't beat the area!

Trip: Mt. Hood - Cooper Spur Date: 1/15/2009 Trip Report: Went up the Cooper Spur 1/14 -1/15. Some notes: Avy danger was listed each day somewhere between moderate and considerable. Our on-slope judgment was that it was somewhere between zero and zero. It's one gigantic, consolidated, impenetrable layer. Even with afternoon warmth there's no way it was going to slide. Zero rockfall, even with forecasted temps 45+. The Tilly Jane trail is a disaster. Bullet-proof, trees down, branches everywhere. Absolutely perfect climbing conditions (rock-hard snow for front-pointing), and really, really, really terrible ski conditions. The North Face and Black Widow look to be in perfect shape. Here are some pictures, there are more on my website www.chrisaerickson.com