As a climber, who sport[1] climbs in really popular areas such as Rumney[2] in NH, I have run across this situation and rappelled rather than lowered many times (the idea that the rappel is less strenuous on the anchor due to less friction heat).

This information is awesome, but it's alternating between "Whoa" and the eternal climber question: "Do I trust my life with this?"

[1]http://en.wikipedia.org/wiki/Sport_climbing

[2]http://www.rockclimbing.com/routes/North_America/United_Stat...

Oh wow, this begs the question: How many HNers are climbers? I'd love to organize a climbing trip somewhere! I'm in MD but just came back from Seneca Rocks and planning a trip to NRG or RRG this fall. I was literally reading that post earlier today from another climbing blog I read.

edit: or the Gunks if someone else leads. I don't think I'm comfortable yet at the sharp end of the rope.

I too am from MD and a climber too. It would be interesting to get a poll going to see how many people here are interested in climbing.

Also figure I might as well inform you of an organization for local climbers in DC area one of my friends has started: http://www.dcmetroclimbing.com/

I climb at Earth Treks Columbia twice a week. I have been wanting to organize a climbing trip for HN folks to introduce people who are new and meet people who already climb, and now that I know there are at least some of us @ HN, this is more and more a possibility.

edit: thanks for the link!

Cool. Let me know if anything gets organized. My friends and I frequent ET, but I mainly goto the Rockville one. I also work part-time at a very small climbing in Rockville (2 out of the 4 hrs its open a week).

I live in Lexington, Ky and am in the RRG very frequently. My girlfriends father owns the land behind Miguels. I would definitely like to meet up if/when you guys come down.

I'd love to start a mailing list of hn climbers. Send off an email every time you visit a popular crag. I'd be willing to start one, just need everyone's emails.

Colorado here, or I'd offer to lead. ;)

(One weakness of being self-employed is that when someone wants to take the day off and go climbing with me, I have very few reasons to say 'no.')

I have been climbing for years all over Southern California, Mammoth, Bishop, Red Rocks. I would be down for a HN trip in CA or nearby.

I've got a harness and some gear, but I have yet to find the time to begin learning how to safely use it, so I haven't gone out yet.

I'm an SF climber. Mainly haunt Planet Granite in the presidio. Also do w/e's in Bishop and Yosemite.

I also climb in SF (Mission Cliffs) and try to go outdoors but not enough. Usually local though, Diablo, Mickey's Beach, Castle Rock, etc

I'm a long-time climber from Pittsburgh. I've spent too many weekends to count at the NRG.

It would be interesting to see a statistically significant number of data points on this test. I wonder about variability of the max load on the used anchors vs. new ones. I think I'd prefer a known max load to one that might be greater, but is unknown.

Is anyone making anchors designed with a notch?

Modern anchors and carabiners are designed to take the load on its spine, which maximizes their strength. However, that's not always what happens nor are the ideal conditions of the lab are what climbing equipment is usually exposed to. Carabiners and cold shunts can take 25-30kN where a 200lb climber exerts less than 1kN force statically. The issue is not with holding weight, but taking on dynamic forces in the event of a fall, so much so that ropes have to be retired after roughly dozen UIAA factor-2 falls[1] because they lose their dynamic properties.

I don't think making grooved anchors and cold shunts makes that much sense because in the event of a fall, the rope or carabiner supporting you to that shunt is absolutely not guaranteed to stay in place. I can say I've taken a few 20ft whippers that knocked the protection around.

I think what's much more important is climbers' lucidity on the rock and following established procedures. Whether a piece of protection can support the weight of a large truck or a large truck and some tires is less important than whether a climber followed all the proper procedures to minimize their risk exposure.

Failed equipment accounts for a negligible percentage of all climbing accidents.

[1] http://www.theuiaa.org/

This is extremely important to note. I would absolutely not buy a notched carabiner any time soon, and as far as I am aware, nobody makes them for climbing purposes.

However, as a counterpoint, it's rare that people take big dynamic falls on rappel anchors, as you don't usually climb above them nor have the kind of slack when finished with a climb that would cause this. Even so - I still prefer the idea of a simple, crazy strong, anchor.

I personally would think that work-hardening could also play a part in this. By the look of the anchors they are likely made of stainless steel, most grades of which will work-harden under the correct circumstances.

I am only familiar with the effects of work-hardening in a workshop situation though, so I'd hesitate to say for sure what the effect of that kind of friction/strain load would be...

I thought that one could use this info to design a better anchor. Couldn't you just recreate the same effect sans sharp edges?