Wednesday, August 8, 2012

Rapelling Accidents

Another rappelling accident in the Rockies, this time a young man rappelled off the ends of his rope somewhere up on Castle Mountain. This brings the total - reported in the media (there could be more) - to three in less than two weeks. In the first, a mis-rigged rappel device resulted in a ground fall from 20 metres up, in the second, two climbers died after one apparently rappelled off the end of their rope while they were simul-rappelling, and the third is reported above.

Many climbers, and even the general public, frequently claim that rappelling is the most dangerous part of climbing, and, with the incidents in the last three weeks, one might be tempted to think they are right. However, I am not convinced this is true. Technically, rappelling is one of the easiest skills to master in climbing, and numerous back-up safety options are available. Learning to route find, place gear, build multi-directional gear anchors, and even master complex psycho-motor skills associated with making certain climbing moves are all harder than rappelling (particularly from bolted belays).

I came across this interesting article by climber Steph Abegg who took US mountaineering accidents reported in the annual publication "Accidents in North American Mountaineering" (ANAM) and presented the data from 1951 to 2006 in graphical form. Of particular interest is the chart labeled "US Mountaineering Accidents by Immediate Cause" in which only 3.2% of accidents were primarily attributed to rappel failure or error.

Of course, as always, there are problems with the data set used for this analysis as only accidents reported in ANAM enter the raw data and it is certain that many more accidents go unreported. However, even with this caveat, it is clear that rappel accidents can not possibly be the most dangerous part of climbing. In fact, if you group together falls/slips on snow/ice and rock fully 50% of accidents are accounted for.

It's tempting to think that the rash of recent rappelling accidents underlies a more serious problem in the climbing community, but, any statistician will tell you that random events are not necessarily randomly distributed and, in fact, tend to cluster.

What is disturbing is that so many climbers are unable to safely manage one of the simplest psycho-motor and technical skills that one encounters in climbing (note that none of these accidents involved anchor failure, they were all failures of technique). I'm left to wonder if one reason for these accidents is that the climbers are able to manage as long as everything is running smoothly, but, put one tiny glitch in the mix, such as lateness of the day, and they have no repertoire of tricks in the tool-bag to manage any deviation from normal.

Climber on a simple rappel
 

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