eyecave wrote:if you was to shove something soft and flexible and big enough into the spot where the nylon hits the metal
it could stop you suddenly if it got sucked up into the bars.....always have this in mind before any rappel, add it to that checklist that you either do deliberately or instinctively at each rappels brink..........think about what you would use....for the brainless.....flesh and hair often isn't tough enough to stop the weight and friction stuff completely so avoid that
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I'll surely regret taking part in this discussion, however...
This ranks among the worst "advice" I've seen spewed on CaveChat. Exactly
what are you suggesting someone jam into their rack to cause an instantaneous halt of their uncontrolled rappel? What do you think this would do to the rope at the point of jamming combined with the extreme shock of this sudden stop, which would be near the same shockload as taking a fall onto the rope? Everything on my person while rappelling is attached to me, anything soft like clothing would feed up into the rack, at best requiring a changeover, and in the worst case pinning the rappeller into the rack where they are unable to change over.
Yes, if the pitch is long enough that you won't crater while doing it,
and you're not so out of control that you're able to quickly add a bar,
and you actually have additional bars to add... then by all means add a bar while making sure not to orient the rope in such a way that you reduce friction in the process of adding the bar. Jamming a foreign object into the rack? Stupid.
Here is my advice, for any person confused enough to read this thread into its second page:
- Don't get into situations where you will go into an uncontrolled descent; always start a rappel with more friction than you'll need.
- Tune your rack! In my opinion, the perfectly tuned rack requires the bars to be manually spread in order to initiate rappel, and the bars close under the rappeller's weight to slow or stop descent if not tended. I found that, for me, a 12-inch rack didn't give me this performance, so for any drop too big for my micro-rack, I use an 18-inch rack with 7 bars. The extra length lets me put more bars on the rope than necessary, and I must spread them to rappel. You may find that a combination of different bars and/or small spacers let you achieve this with your rack. This setup isn't always possible to achieve with varying rappel conditions, but is a goal to strive for.
- Have a hyperbar on your rack so you can quickly, always add friction without fumbling with bars. Practice quickly looping the rope up over it and pulling with your brake hand; it squeezes your rack bars together using mechanical advantage in addition to the extra friction of the bar itself. But remember to loop the rope in the direction that doesn't reduce friction during the operation (don't accidentally remove a bar while engaging the hyperbar!).
- Practice, practice, practice stopping yourself with a quick leg-wrap as soon as you feel your speed go beyond control; you will not have time to perform clever maneuvers at freefall velocity. This will hurt; the alternative hurts much more. Shorts are not appropriate rappelling equipment, wear pants.
- Consider using an auto-stop rappel device. This includes autobloc knots like the so-called French Wrap or devices like the Petzl Shunt with a rack; also auto-stop bobbins, for drop lengths where they are appropriate. Train with it. Train some more. This is religiously argued about, so read and decide for yourself if you feel this appropriate: 1, 2, 3, 4, 5, 6