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Purcell prusik and rap extender

Original Post
MyFeetHurt · · Glenwood, CO · Joined Oct 2011 · Points: 10

I recently started using the purcell prusik in lieu of a metolius PAS. The problem is, now I keep finding myself on rappel without a way to extend the device like I am used to with the PAS clipped midway. It's not a big deal but like extending the device and often use an autoblock. I suppose I can use a dyneema sling but I'm trying to get away from the dyneema for that use, and that makes one extra thing hanging off my harness to get in the way. Is there an easy solution to this that I am missing?

David Coley · · UK · Joined Oct 2013 · Points: 70

Just the belay plate's locker on a clove hitch on the purcell.

people.bath.ac.uk/dac33/hig…

gives an image

rgold · · Poughkeepsie, NY · Joined Feb 2008 · Points: 526
Stone Nude wrote: I honestly have no idea what the big deal is with extending the rappel device away from your body. It seems like more of a religious doctrine thing than anything people have thought through.
It certainly isn't a big deal either way, but I generally extend a Reverso/ATC type device. Nowadays I mostly use the CT Alpine Up, which is maybe-semi-possibly-auto-sometimes locking as a rap device. I use it direct off the harness loop.

The original reason for extension was to get the prussik backup off the leg loop and onto the harness loop and at the same time avoid possible collisions between leg loop prussik and plate---these collisions will release the prussik backup.

But I rarely use a prussik backup with an ATC type device. I still find the extension useful for a few reasons.

1. It makes it less awkward and more natural to have both hands on the brake strand, which provides extra security.

2. You get closer to a 180 degree angle between the rap strands and the brake strands, which means you squeeze a little more friction out of your device. The extra friction is noticeable with thin ropes.

3. It is easier to add significant extra friction to the system (again, a thin rope issue), by adding carabiners to the harness loop and the device loop and running the brake strand through them, and this can be done in the middle of the rappel.

4. If, for some reason, you want to carry the rope down with you rather than throwing it, the extended rap sling makes a good shelf to flake the rope on. For me this works better than making butterfly coils for "saddlebag" slings carried on the side.

5. The second person down can already be attached to the rope ready to rappel when the first person starts. This saves a bit of time if the party divides tasks appropriately and is SOP if the second is a beginner. The time savings increase if there are three people in the party.

6. You can use the guide mode ascending trick if you have to go back up the rope (see blog.alpineinstitute.com/20… .)

There are, of course, some drawbacks.

1. If the second is already attached and ready to rappel, the first person down can't test whether the rope pulls smoothly.

2. If you have a very low rap anchor, it can be trickier to get started.

3. The device will grate against the rock as you go over overhangs. This may not matter much, but it is a little disconcerting.
Rob D · · Queens, NY · Joined May 2011 · Points: 30

the answer to how to extend a rappel without a pas is pretttyyyy simple: a sling. You use one alpine draw and girth it to your harness (or if you want to be anal, use a locker there).

Capt. Impatient · · Unknown Hometown · Joined Jul 2012 · Points: 0

So... Do what you want but if your rappelling and you are with other climbers. Use a fireman's backup. That is your partner holding both ends of the rap line and if you lose control they just pull down on the ropes. If you're by yourself then back it up. I use the PAS when rope soloing. Only because I put my rappel device mid way and then clip in with the end of the PAS. Then when my rappel is set I can weight that with a prussik backup and be sure it holds before I unclip.

Bill Lawry · · Albuquerque, NM · Joined Apr 2006 · Points: 1,812
MyFeetHurt wrote:... using the purcell prusik ... on rappel without a way to extend the device .... Is there an easy solution to this that I am missing?
Maybe try this ...
  • with it girthed to your harness tie-ins as usual,
  • fully extend it
  • and then bend it in ~half back on itself (or bend at appropriate point);
  • near the bend point,
  • tie an overhand or figure 8
  • and then clip the biner of the rap device
  • through the bend point which should now be a closed loop due to the knot.

You may need to do something with the loose end. Clip back to belay loop? ... and then there'd be no way for it to slip back through the knot?

I haven't tried this. I don't use a purcell prusik - although I imagine I would if I did more single-pitch climbing where one needs to rap back down off the anchor.
Guideline #1: Don't be a jerk.

General Climbing
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