Re: newbie friction question
Quote:
Originally Posted by bcubed
Since it seems that a great deal of this accident was due to a lack of friction I have some newbie questions relating to friction on a rappel device. I am somewhat new to canyoneering and most of my rappelling experience is in climbing i.e. thicker ropes and double strand rappelling.
I recently purchased a Petzel Piranha to rappel with and I really enjoy the ability to adjust friction on it but I haven't done a long rappel on it. I was wondering what friction mode it needs to be put into to be comparable to say the friction from an ATC guide (which I previously used)? If I were to do the 300' rappel that this thread is discussing would I need to put as much friction on the the pirahna as possible AND use a leg carabiner or would the piranha by itself be able to provide enough friction?
I apologize because I do realize this question is likely a bit ambiguous but I would rather ask here then get a video posted of me here falling down a 300' rappel.
As a frame of reference for the friction I would need I weigh about 155 lb.
The other big factor is what rope you are on. Not only brand and size, but also condition (new, old, fuzzy, slick) or wet/dry.
You got a cliff near where you live? While we could give you a formula for what setting to use at your weight and on X rope, it is better to understand the variety of settings and how each feels on a variety of ropes. WITH A BOTTOM BELAY from a friend.
Then, on a long rappel, the weight of the rope makes a big difference across the length of the rappel. At the top, the weight of the rope will slow you down, a LOT, and you will need to be set up 'light'. About halfway down, you will want to make an adjustment. Since there are not ledges on this particular rappel, you cannot easily use the Pirana adjustments to add more friction. I use the opposite-leg-loop biner method, but other method work too.
Which is a bit beyond the capabilities here...
Tom
Re: newbie friction question
Quote:
Originally Posted by ratagonia
Since there are not ledges on this particular rappel, you cannot easily use the Pirana adjustments to add more friction. I use the opposite-leg-loop biner method, but other method work too.
Umm, I may be about to make myself look stupid, but why can't you add friction with the Pirana? Admittedly you're more limited double roping than single lining but you can just wrap the rope around on the right hand side, assuming you're right handed. (Twice around and you're basically stopped and could take your hands away without a stopper knot, not that it's a good idea, at least on the 9mm rope I've used with it - but you can't wrap round twice when double-lining)
Re: newbie friction question
Quote:
Originally Posted by zoeimogen
Quote:
Originally Posted by ratagonia
Since there are not ledges on this particular rappel, you cannot easily use the Pirana adjustments to add more friction. I use the opposite-leg-loop biner method, but other method work too.
Umm, I may be about to make myself look stupid, but why can't you add friction with the Pirana? Admittedly you're more limited double roping than single lining but you can just wrap the rope around on the right hand side, assuming you're right handed. (Twice around and you're basically stopped and could take your hands away without a stopper knot, not that it's a good idea, at least on the 9mm rope I've used with it - but you can't wrap round twice when double-lining)
Not to speak for Tom, but I think the point he is making is. On a rappel of 300 ft. where you are either free hanging or slightly touching the wall. As you get to the bottom it is pretty hard to bring yourself to a stop to add friction over one of the hooks. So you either have to rig it heavy at the top and then deal with the lack of friction at the bottom or increase your friction as you go down. If you can make it happen then yes it will work. That is one of the concepts behind all the hooks on a piranha.
When wanting to tie off on your piranha I do it a little different then you described. I wrap it once around the hooks bottom to top and then put the slack end thru the carabiner and hook it on the hook on the other side. Its bomber.
You also brought up being right handed. If you are left handed just flip the piranha around on your carabiner this gives the lefty the same
choices.
Hope that all made sense.
Mark
Re: newbie friction question
Quote:
Originally Posted by moab mark
Not to speak for Tom, but I think the point he is making is. On a rappel of 300 ft. where you are either free hanging or slightly touching the wall. As you get to the bottom it is pretty hard to bring yourself to a stop to add friction over one of the hooks. So you either have to rig it heavy at the top and then deal with the lack of friction at the bottom or increase your friction as you go down. If you can make it happen then yes it will work.
OK, so I guess the point is that with a Z-rig or similar, if you're using wiregates then you can basically just shove the rope through the gate and it'll slow you even if the rope is still moving.
Quote:
When wanting to tie off on your piranha I do it a little different then you described. I wrap it once around the hooks bottom to top and then put the slack end thru the carabiner and hook it on the hook on the other side. Its bomber.
Oh, I tie off as it shows in the manual, with a knot - I woudln't actually take my hands off just having wrapped around twice. It's enough friction to keep you steady but could still slip off.
Quote:
You also brought up being right handed. If you are left handed just flip the piranha around on your carabiner this gives the lefty the same choices.
Yes, wasn't sure how I should indicate the, uh, spikey side as opposed to the offside you're not braking with :-)
Re: newbie friction question
Quote:
Originally Posted by zoeimogen
Quote:
Originally Posted by ratagonia
Since there are not ledges on this particular rappel, you cannot easily use the Pirana adjustments to add more friction. I use the opposite-leg-loop biner method, but other method work too.
Umm, I may be about to make myself look stupid, but why can't you add friction with the Pirana? Admittedly you're more limited double roping than single lining but you can just wrap the rope around on the right hand side, assuming you're right handed. (Twice around and you're basically stopped and could take your hands away without a stopper knot, not that it's a good idea, at least on the 9mm rope I've used with it - but you can't wrap round twice when double-lining)
I am not fond of the ways to adjust the Pirana friction in combat. Going for the upper hook, you pass briefly through a lower-friction position before getting there - not so good when things are on the edge of control. The positions you can get to without going through the soft spot are TOO much friction.
Tom :moses:
