Another rappel faiure

[gary_hehn]

Yes Paul and goatboy, walking could be part of the issue. But, I'm thinking even more generally and in the context of rappeling from a camming device. Which, by the way, I have never done. But, never say never. Hopefully it would at least have a reasonable backup. As has been stated, why would I do that anyway if I have something far less expensive and at least as suitable to leave behind? I always carry a range of six tricams in my rack plus the two pitons previously mentioned.

 

goatboy wrote: I would say that most anyone who uses and relies on cams regularly to protect lead falls (with a high impact force) should be more than capable of incorporating cams into a very safe, redundant equalized anchor system while visually assessing their placements.

 

I agree, but then how many placements are we considering leaving behind, two, three? And yes, good cam placements are hard to beat and nearly always reliable.

 

What ever you are using, I'm sure I don't have to remind you that you are trusting your life to it! This may be more of a personal thing, but personally I would not be comfortable rappeling from a single cam placement no matter how good it looked. Think about it, how can you really know how good the placement of a cam is.

 

A good place to experience this uncertainty is on Ingalls Peak. I believe the polished rock there is serpentine. You can make a stellar cam placement there and it will simply pull out with little effort. Now, of course, Ingalls presents an extreme, but it shows that what looks good when it comes to cams isn't neccessarily so. I have seem good placements pull from dusty granite.

 

I guess there are no real guarantees no matter what you use. Although, as I stated earlier, I believe a wedged piece is easier to evaluate and determine to be good. You can at least be certain that something has to shear for there to be a failure, not just simply slip or walk out of position.

 

Again, I'm not necessarily suggesting that it should never be done; I'm just suggesting that one should be WARY of it. And of course, if you're in a pinch and that's all you've got. Well then, that's all you've got. Hope I'm never in that pinch.

[mattp]

I think there is nothing inherently less reliable about a cam placement than a nut. Afterall, you can often place a cam in what would otherwise be a good nut placement and it is more secure than the nut because it will not fail when pulled upward or outward (yes something not likely to happen when you are actually on rappel but possible when you are setting up to get started). The possibility of a walking cam is much greater when fooling around at the starting point, too. Once you've started your rappel, I think weighting/unweighting the rope is not likely to cause a cam to walk unless you have some fancy rescue-type equalizing set up where things may move around given unequal weighting or perhaps when you make a diagonal start or something.

 

Of greater concern with regard the reliability of a cam as a rappel anchor, I think, is that you can and may well use a cam in a spot where a nut would not go and which is inherantly less secure - like a parallel sided crack in shiny rock, as Gary describes, or a flaring crack, or behind a loose flake, etc.

[korup]

Is there any difference between the dynamic, sudden forces (say a leader fall) and the softer pull from rapping in slippery rock? In other words, with a leader fall, the cam lobes are suddenly set tight (breaking through surface garbage etc.), whereas rapping, it might slowly walk out of a greasy crack? Pure speculation.

[catbirdseat]

I really don't think it matters. The normal force as a percentage of the downward force will always be the same, regardless of whether it is a shock load or a static load.

[PaulB]

Why would they do that? If they are properly placed and connected to the anchor slings they should not walk.

Probably true for a well built anchor, but in the case of a single cam, I'd say it's possible. I seem to recall reading that Jean-Christophe Lafaille watched his partner fall to his death on the South Face of Annapurna when their single cam rappel anchor failed.

[goatboy]

The story with LaFaille was that it was a single small cam placed in bad rock -- when he stopped on a ledge, as described in the previous post, the cam shifted and ultimately failed when he weighted it again, leaving LaFaille stranded on the big wall . . . .

 

This could happen as well with any micro-placement in bad rock -- I believe that cams, however, used as components in a larger anchor system, can be ultimately very safe, reliable, and assess-able.

[fheimerd]

I arrived at applebea half an hor before it happened. Everyone at camp heard rockfall mixed with a person screaming. As we later found out the gruesome details of what heppened it was hard not to think about what went through the guys head as he was falling, what his friends thought, and how his family would cope with it. All for a camera that was probably already busted. The positive thing was how everyone came together to help with the situation and help the people that actually saw it all go down. A couple of bucks for lost gear used to set up an anchor or losing a camera is not worth a life. Climb safe.

[selkirk]

Why would they do that? If they are properly placed and connected to the anchor slings they should not walk.

 

It wouldn't walk if your rapelling straight down, and very statically loading the cam. If there's any side to side wiggle though?

 

It seems like everyone agrees though, use the cheapest but still reliable way down. Back up rappel anchor for the first peole, skinny person pulls the backup and raps last, possibly tying the tails of the rap rope into the new anchor for the next rap.

[JoshK]

Wayne and I both thought that the double rope rap (50m of 7mm perlon + 60m 8.1 ice line) off the west side of west fury on our n pickets traverse was one of the scariest things either of us had ever done. I can clearly remember the feeling of looking up near the end of that rappel at the endless amount of super stretchy thin rope and thinking of what it was attached to. Shuuuuuder...

[Bug]

My general rule of thumb for leaving gear behind is "does it cost more than a day of skiing?" Now that does not meat you could start a rack by following me around in the mountains. I just don't worry about expense when it comes to being able to so an anchor is "good".

I once watched a friend tie his prussick to a carabiner used as a brake bar. I tried to talk him out of it but he just blew me off and bailed. part way down, the prussick stopped and pulled biner out of the brake configuration leaving him with a pulley system. It took three strands of rope to get down from that point. Good thing we were not far up.

[Off_White]

I once rapped the Sherpa Couloir on Stuart. In late September, it was not a friendly descent for the cramponless. Someone else had rapped it fairly recently, there was a set of red slings all the way down, all with the same initials on them. Without fail, each anchor was scary as hell, but a few minutes excavation with a nut tool would reveal a bomber sling anchor. We reset each sling. The last anchor was several slings tied around a large peanut shaped boulder on a sloping gravelly rock bench above the schrund. The previous yahoos had rapped straight down the sloping direction, and you could see that the boulder had moved a couple inches.

 

Just because someone has successfully rapped on something, don't assume everything is hunky-dory. Personally, I wouldn't hesitate to leave anything on my rack behind if that's what it took for a safe anchor. That said, I think I've only left two nuts behind over the years.

[sobo]

...That said, I think I've only left two nuts behind over the years.

 

You should never have let this group hear you say that...

[catbirdseat]

...That said, I think I've only left two nuts behind over the years.

 

You should never have let this group hear you say that...

Hey, it happens to a lot of guys when they get married. They go in a jar high up on the shelf...