Alpinfox

Fred found them to be quite effective on gravel this past summer:

Great post Joseph. I've done the "well lets just give this route a try" thing a few times and it has always been fun. Thanks for the reminder.

Assuming a rope with 9% stretch, as long as the distance between you and your last piece of gear is less than or equal to 1/5 of the total amount of rope out between you and the belayer, you should not generate a force on the anchor higher than 6kN. So, if you have 20m (60ft) of rope out, you can go up to 4m (12ft) above your last piece, fall, and generate a 6kN force on the top piece of gear. How's that for a rough rule? Call it the 1/5th rule.

edit: YO NOLSe! RESIZE YOUR PICTURE! I haven't climbed too many things that aren't in the selected climbs type books, so my answers won't be very original or unique, but: The last two pitches of the West Face of NEWS stand out in my mind due to their incredible position and the fact that the first of the two is my hardest alpine lead to date. The two bolted pitches on DEB of SEWS are really sweet too. I was giggling to myself while climbing that route it was so good. Final pitch & half of Outer Space are incredible. I guess Davis-Holland/Lovin' Arms isn't "Alpine".

Telemarker, your question doesn't make any sense. You will still weigh 175lbs when you come to rest. The force applied to your anchor is determined by the distance you fall, the amount of rope out, and the stretchiness of the rope. You have to take into account the stretchiness of the rope because with a rope with no stretch (not physically possible) you would generate an infinite force (obviously not possible). The question I think you are asking would probably be better stated as, "Assume I tie my rope directly to the anchor, I weigh 80kg, and I fall 1.65m above my anchor with no intermediate pro (total fall distance would be ~10ft) and a rope of average stretchiness (say 8%). What force is applied to the anchor?" Well, the answer to that question, according to my calculation is 20.2kN (or roughly 4000lbs). Now here is the part I'm less sure about: If you were being belayed through the anchor with a perfect pulley between you and the belayer, the force felt by the anchor would be TWICE the above value. However, because biners aren't good pulleys, there is a lot of friction there and the anchor doesn't feel quite TWICE the force. I don't know what a reasonable coefficient of friction for a carabiner is, but Dave's fall force machine gives a total force reading of 32kN, so he is apparently assuming a coefficient of friction of 0.8. I'm no physicist, so I hope someone more knowledgable than myself will review this post and correct me if I'm wrong.

Hey Bugsy, Why'd ya get PRK vs. LASIK?

Cool. Love to see some pics if you got any. Here is a nice TRIP REPORT I found online.

New bag from SIERRA DESIGNS temp rating: 40 degrees weight: 15oz insulation: 800 fill down no zipper no insulation on bottom (use your sleeping pad) price: ~$160 on the web

NICE! Congratulations.

Tempo, Do a SEARCH of this website for past discussions about belay loops.

I occasionally unclip a quickdraw from a lower piece of gear and moved it to a higher piece of gear leaving the quickdraw attached to the rope during the process. I think it is more awkward and strenuous to pull up the rope with the quickdraw than with my hand. I think this is due to the friction of the rope running through the biner.

Your calculation is not correct. It's pretty tricky to calculate the peak force felt by an anchor in a real climbing scenario because of rope stretch, friction at the top biner, and other elasticity in the system. Keep in mind that you are not stopped instantaneously, but over some amount of time. That said, the value you are looking for is, roughly, the kinetic energy (KE) at the moment of impact which is found by 0.5mv^2. So you have to figure out what your velocity is first. Velocity is the square root of 2Gh where G is ~10m/s^2 and h is the height in meters that you fell. Dave's "Fall Force Machine" will come close to answering your question: www.alpinedave.com Click on fall force machine This one is nice because it allows you to change the variables of the fall such as rope stretch and distances between belayer, top piece of gear, and climber. I don't think he has included some variables (like friction on the biners) in his formula, but it's pretty close. If you are interested in a more ideal physical system and some of the math behind the system, check out this link: http://hyperphysics.phy-astr.gsu.edu/hbase/flobi.html Some other equations of interest: To determine how fast you are going after falling for a known time: v = g * t To determine how far you fall in a given time: d = 0.5 * g * t^2

Hey, I just found this TR. I guess I haven't been keeping up with cc.com the way I used to. Anyway, you are welcome. Cheers. I hope Patagonia treats you well! Nick, what the hell are you up to these days? Chimney bouldering in the snow with hexes on the belt and a recent hernia operation? Priceless!

What? You don't like moss, slime, lichen, and low-angled chossy rock? Boy, you're hard to please.

The pictures in old TRs don't show up anymore. Is there some way to fix this? For example, in my Backbone Ridge TR, none of the pictures show up. I resized all of my Backbone pictures with the plan to reinsert them, but the thread is too old so I can't edit it anymore. Can a mod help me with this?

Hey Bug! I don't know why, but I never found this TR until now. I really like the way you spelled my name about four or five different ways - all incorrectly. Champagne (with extension along the ridgetop) is a great adventure climb and a worthy backup plan for when SCW is too busy or you are looking for something a little different. One should definitely be prepared for the ledges as the views and setting are remarkable. Here is a picture of the 5.8 slanting hand crack/dike thing on the crest of the ridge that Bugsy led.

Baker.... Rainier.... what's the difference really? Plexus: Those pics were taken from the top of Powerline Wall and we (or at least I) saw Dallas.

Nice!

Nice pics Gary. I thought about heading up to Red Mtn yesterday, but opted for rock climbin' at Erie instead. So how far did you get? That first section is probably the toughest in winter.

Well, I'd wager your grandmother hasn't spent the last few seasons in Antartica and I'd also wager that your grandmother ain't as good of a photographer as this guy so STFU.

Yes indeed, it was a beautiful day out at Mt. Erie yesterday. It was sunny and warm and wonderfully scenic.

Ya'll were at Erie yesterday? Olyclimber and I had a great time stumbling around in the mud + sticker bushes while lost, but finally found Powerline Wall and climbed a few routes. We only saw three other people all day - Dallas Kloke and two bumbly kids. Where were you? Erie/Vantage/Tieton/Smith/Index/X32/X38 can all provide winter rock climbing opportunities. Just need a sunny day or two. Erie, being south-facing and at sea level is probably one of the warmer and faster-drying options. Stone Gardens and Vertical World are usually warm and dry as well.

I got a nice e-card from Squid!