Quote
basilbop
One thing to think about: if you were to "clip into" the Half Dome cables and slipped, the carabiner would slide down the cable to the next pole until it abruptly stopped the fall. It seems that this very well could result in injuring the hands of everyone holding onto the cables between you and the next lower pole. Also, unless you are using a dynamic device specifically made for this kind of use (such as those made by Petzl or Camp for the "via ferrata" that are common in Europe) the forces encountered when the carabiner is stopped by the pole could cause significant injury--most climbing hardware isn't designed for use without a long dynamic rope to help dissipate forces. (The "via ferrata" gear is specifically designed to dissipate forces within its comparatively short length.) The Half Dome cables were not designed for people to clip into, and I don't believe that this is necessarily a safe approach, either for the person clipping in or the others below this person...
No. That's not the point. This is not an overhang, and people who are having problems don't suddenly let go. They just can't hang on tight enough, and slide down to the next crossbar while fighting it all the way. A person with a carabiner rig is not much more dangerous to others than the guy without one who can't hold on tight enough....less so, since he will stop at the next pole and not keep sliding down through the crowd below that.
I actually have a via ferrata rig, and have used it with a Downs kid who went up Half Dome with us. It does have a foot or two of dynamic braking, which is very helpful in a vertical fall, but not so important as its having two carabiners, so that you are never fully unclipped while passing a support point. If you haven't seen one of these, they consist of a short rope with a carabiner on each end, that attaches to you in the middle. While you are moving, only one end is clipped to the cable. If you fall, when the attached carabiner hits a stop on the cable, the middle gizmo that is clipped to you is a dynamic brake as it slides along the rope to the unattched carabiner. When climbing, as you get to a cable support, you clip in the unattached end above the support before unclipping the other one below it.
Anyway, the principal use of a carabiner rig is to clip in and and sit down to rest on a crossbar (if you are terrified or exhausted) while others can safely pass over you in either direction. Even a single carabiner works for that. This is a big safety plus compared to situations that I have seen where people just hang on the cables and scream....
So: Yes, if you see someone using a carabiner rig, don't follow too close. Or be prepared to shift to the other cable. But that applies to anyone above you who seems to be having trouble hanging on. Always try to stay one support pole back.