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minimal carabiner for Munter rappel

PostPosted: Wed Feb 24, 2010 8:17 pm
by MoapaPk
Yesterday I tried a Munter rappel with the modest gear I often carry on class 3/4 "hikes," when other folks are along.

I was surprised how well it went considering the materials -- two 50' pieces of webbing (10/16" and 9/16", tied), a sling over a large (5-ton) wedged rock, a locking carabiner, and light harness. I was able to go down some vertical stuff, which I certainly wouldn't try with a dulfer. The locking carabiner was a modest-sized BD offset D, and I was watching how the hitch moved as I descended, rather nervously; but aside from some funky deformation of the webbing, and noticeable warmth, all was fine. (I know I'm supposed to use a pear-shaped carabiner, but if I had one of those along, I would probably have better stuff all around.)

Bear with me; remember that this testing was meant to scope out emergency situations. I'm not a climber, and would never plan on using this stuff for a normal situation.

Question: would you ever consider an emergency rappel, not very long, with a Munter hitch on a non-locking carabiner? A wire-gate carabiner? I rappeled just twice, and both times the hitch seemed to keep securely on one end; I couldn't see an obvious mode of failure for a wire-gate carabiner, but somehow the mere thought of a non-locking carabiner was creepy.

PostPosted: Wed Feb 24, 2010 8:50 pm
by rhyang
You can buy a BD vapor lock for $12-15 (blems / seconds are cheaper). They weigh 50-ish grams.

http://www.blackdiamondequipment.com/en ... -screwgate

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I use one with a petzl reverso 3 for alpine stuff.

PostPosted: Wed Feb 24, 2010 9:14 pm
by MoapaPk
rhyang wrote:You can buy a BD vapor lock for $12-15 (blems / seconds are cheaper). They weigh 50-ish grams.


That's very similar to the one I used yesterday -- 54 grams. I'm not sure they make anything exactly like mine anymore.

The light carabiners have a pretty dramatic cross-section (perpendicular to the unit, though the metal), and I think they put more stress on the rope/web being fed through the hitch, than would occur the heavier kind with a rounder cross section... but for an emergency, I'll deal with that!

PostPosted: Wed Feb 24, 2010 9:24 pm
by nartreb
I always carry not one, but at least two, large locking 'biners just in case I drop the one with my ATC (edit: actually a reverso 3 unless I'm toproping) attached to it. I can certainly think of a failure mode involving a non-locking 'biner and stopping on a ledge so the hitch and 'biner come unweighted and can move. Should be OK if you watch it carefully, but why take the risk?

I'd also be a bit nervous about heat damage to webbing - again, a short rap should be fine but why not carry a rope instead of that much webbing? If you know you're only using it to rap, it doesn't have to be thick or even dynamic, so it can be light and cheap. I find that rope is easier to handle than webbing.

PostPosted: Wed Feb 24, 2010 9:34 pm
by The Chief
My Auto Lock of Choice for all belay/raps, including the occasional single rope munter belay and rap...

DMM SHADOW AUTO LOCK 56gm & rated at 24kn $15.95:
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****The regular screw lock weighs in at 51gm and is also rated at 24kn.
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PostPosted: Wed Feb 24, 2010 9:40 pm
by MoapaPk
nartreb wrote:I'd also be a bit nervous about heat damage to webbing - again, a short rap should be fine but why not carry a rope instead of that much webbing? If you know you're only using it to rap, it doesn't have to be thick or even dynamic, so it can be light and cheap. I find that rope is easier to handle than webbing.


I know this is hardly an ideal set-up. On class 3/4 "hikes," I find webbing makes better handlines, kinder on the hands for the weight.

I was thinking of a situation from about 10 days back, over a route where normally handlines would be more than adequate. I had been on this route 5 times before without incident.

The last section involves a drop down a steep-walled canyon, then a traverse to avoid a big drop at the end. When we hit the traverse (on steeply-sloped sandstone ramps), we found the rock was now covered with fine sand washed down from the recent rains; the rock was much more slippery than normal. We had a significant bottleneck, with some folks who didn't want to chance following a set of minimal cracks across the sandstone, and I can't blame them one bit. I had the same gear with me then, and opted not to climb back up for the rappel, because I didn't want to try something for the first time, with 9 other people.

We found a little cave for an upper strong person to act as a meat anchor, and had two meat anchors on the other end, and used a handline. For this particular hike, next time we'll bring real rope and real ATCs, rap, and avoid the traverse.

PostPosted: Wed Feb 24, 2010 9:42 pm
by nartreb
(oops - meant to edit previous post, accidentally created a duplicate)

PostPosted: Wed Feb 24, 2010 9:42 pm
by MoapaPk
...and thanks all for the good comments.

Re: minimal carabiner for Munter rappel

PostPosted: Wed Feb 24, 2010 9:51 pm
by cp0915
MoapaPk wrote:Question: would you ever consider an emergency rappel, not very long, with a Munter hitch on a non-locking carabiner? A wire-gate carabiner?


In an emergency, of course.

Re: minimal carabiner for Munter rappel

PostPosted: Wed Feb 24, 2010 9:54 pm
by cp0915
squishy wrote:
cp0915 wrote:
MoapaPk wrote:Question: would you ever consider an emergency rappel, not very long, with a Munter hitch on a non-locking carabiner? A wire-gate carabiner?


In an emergency, of course.


I might consider a body rappel 1st...over a single wiregate...


The body rappel does work quite nicely, but it's a touch creepy when things go vertical. Or maybe it's just me...

PostPosted: Wed Feb 24, 2010 10:17 pm
by SWH
Athletic tape can go a long way in making a non-locker into a poor mans locker... but I think that I would still go for the body rappel over a single wiregate. Got to learn those old-school skills, they might come in handy someday.

PostPosted: Wed Feb 24, 2010 10:23 pm
by rhyang
MoapaPk wrote:
rhyang wrote:You can buy a BD vapor lock for $12-15 (blems / seconds are cheaper). They weigh 50-ish grams.


That's very similar to the one I used yesterday -- 54 grams. I'm not sure they make anything exactly like mine anymore.

The light carabiners have a pretty dramatic cross-section (perpendicular to the unit, though the metal), and I think they put more stress on the rope/web being fed through the hitch, than would occur the heavier kind with a rounder cross section... but for an emergency, I'll deal with that!


The difference is that the vaporlock is actually made for belay / rappel duty, including munter hitches. But if you've got something you're personally comfortable with, then by all means use it :)

Most climbers are taught that rappelling is one of the most dangerous things in climbing. My life is worth more than $15.

PostPosted: Wed Feb 24, 2010 10:36 pm
by Autoxfil
SWH wrote:Athletic tape can go a long way in making a non-locker into a poor mans locker... but I think that I would still go for the body rappel over a single wiregate. Got to learn those old-school skills, they might come in handy someday.


Why? If you have a rope, carry a runner and a locker. Always.




My setup for situations like that is 75ft of 8mm static - 2lb - and a runner and locker for each person.

It sounds like the OP REALLY wants to buy and read Craig Connally's Mountaineering Handbook. Tons of good advice on light and fast semi-technical travel, with good tech to back it up.

PostPosted: Wed Feb 24, 2010 10:47 pm
by nartreb
Mine are Mammuts - tough to keep the models straight but I think they're the Bionic Mythos HMS - 58g, 24kN, about $16. Really roomy, which is what I like in a harness biner. Also a very smooth, reliable screw action.

(I find the metolius element [again I'm going by photos, I think that's the same 'biner I have a few of] is just too small for most uses, especially with gloves on. The gate doesn't allow much clearance to get a rope through - even an anchor cordelette can be a bit of a pain to clip in a hurry. )

PostPosted: Wed Feb 24, 2010 10:54 pm
by MoapaPk
rhyang wrote:
The difference is that the vaporlock is actually made for belay / rappel duty, including munter hitches. But if you've got something you're personally comfortable with, then by all means use it :)

Most climbers are taught that rappelling is one of the most dangerous things in climbing. My life is worth more than $15.


I was actually thinking of the vaporlock as one of the lighter carabiners -- compared to those with rounder cross-section, which weigh 80-100 g. I looked through BD's listings, and the vaporlock seems to be the successor to what I used. The construction looks very similar, except there is more of a recurve opposite the gate, in the newer model. I think you might have misread my imprecise language. Anyway, your recommendation gives me more confidence.