MoapaPk wrote:Slight thread hijack...
In very obscure areas of Red Rock, NV, I've found pitons used as rappel anchors. Some folks tell me they will never rappel off pitons. But I talked to the guy who placed one, and he told me that he was sure it was really stable. That one piton has probably been used for more than 50 rappels (only about 70 feet). It doesn't seem to have moved.
Unfortunately I can't remember the exact source, but there's this pretty interesting study conducted among alpine guides (ie: professionals) in europe a while ago that focused on the reliability of in-situ pins. The guides were asked to judge the reliability of pins that had been in place for an unknown amount of time. Afterwards, these pins were tested to see how much they would hold. Turns out, none of the guides consistently got it right; reliable looking/sounding/feeling pins came out at a pop, thrashy looking ones turned out to be bomber and vice versa. Lesson I took away from that is that it's very hard to judge the safety of an in-situ pin. Sometimes you won't have any other options for descent but to rely on pre-placed pins, but I always try to back up the first person to abseil with a cam or something, and if I don't trust it than I'll leave some prusik cord to back the whole situation up.