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minimal carabiner for Munter rappel

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Postby The Chief » Wed Feb 24, 2010 11:03 pm

MoapaPk wrote: 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.


Be advised that they are now made in China.
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Postby MoapaPk » Wed Feb 24, 2010 11:11 pm

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.


I can hardly claim to be an expert on the dulfer, having tried it just on 45 degree slopes; but I remember thinking, "people must have worn much thicker clothing when this was popular."

Folks, recall that I'm talking about an unusual circumstance. There are times when all I have is a wire gate carabiner, mainly for quick hoisting of packs. I was most curious to hear possible failure modes for a non-locking biner with a Munter, and I heard enough to convince me to carry the 51 g locking carabiner instead.

There is a tendency for this type of thread to go off toward peoples' experience with intentional technical trips; that's not my focus, but I'm still happy to hear your experiences. There is a compromise that must be met, between carrying stuff to prepare for every possible situation, and knowing how to avoid those situations in the first place. I'm still adjusting that compromise.
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Postby The Chief » Wed Feb 24, 2010 11:40 pm

MoapaPk wrote:
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.


I can hardly claim to be an expert on the dulfer, having tried it just on 45 degree slopes; but I remember thinking, "people must have worn much thicker clothing when this was popular."

Folks, recall that I'm talking about an unusual circumstance. There are times when all I have is a wire gate carabiner, mainly for quick hoisting of packs. I was most curious to hear possible failure modes for a non-locking biner with a Munter, and I heard enough to convince me to carry the 51 g locking carabiner instead.

There is a tendency for this type of thread to go off toward peoples' experience with intentional technical trips; that's not my focus, but I'm still happy to hear your experiences. There is a compromise that must be met, between carrying stuff to prepare for every possible situation, and knowing how to avoid those situations in the first place. I'm still adjusting that compromise.


I have done several Munter Raps on a single fat BD Oval rated at 24kn and OP Five-O Wire Gate rated at 28kns with no ill results. Never had the gate open on me while rapping either.

One must remember that Rapping only puts Static Loads on a biner. Much different than the Dynamic Load of a fall.

Just remember that if you only have one biner, keep the gate facing down and away from you as the Munter tends to slide up and towards ya. Keeping the gate in this pos, if it does indeed open, will keep the Munter on the biner and on your harness.

Also, BD Biners are now made in China.... Ahhhhhhhhhhh!
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Postby MoapaPk » Wed Feb 24, 2010 11:55 pm

The Chief wrote:Just remember that if you only have one biner, keep the gate facing down and away from you as the Munter tends to slide up and towards ya. Keeping the gate in this pos, if it does indeed open, will keep the Munter on the biner and on your harness.

Also, BD Biners are now made in China.... Ahhhhhhhhhhh!


Thanks Chief... so maybe I'll keep the old BDs! They really haven't seen much load over 7 years.
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Postby Autoxfil » Thu Feb 25, 2010 12:50 am

MoapaPk wrote:Folks, recall that I'm talking about an unusual circumstance. There are times when all I have is a wire gate carabiner, mainly for quick hoisting of packs. I was most curious to hear possible failure modes for a non-locking biner with a Munter, and I heard enough to convince me to carry the 51 g locking carabiner instead.

There is a tendency for this type of thread to go off toward peoples' experience with intentional technical trips; that's not my focus, but I'm still happy to hear your experiences. There is a compromise that must be met, between carrying stuff to prepare for every possible situation, and knowing how to avoid those situations in the first place. I'm still adjusting that compromise.


Here's my take:

If you're bringing a rope, or even a bunch of webbing, you're preparing for some technical sections - maybe just potential sections, but you're prepping.

Good choice on making the biner a locker. It's worth a few grams, for sure.

I suggest bringing rope instead of webbing. 8mm weighs less than 9/16" webbing, and is more abrasion resistant and more versatile. When rappelling you often abrade the cord, and abrasion on webbing is a very scary thing. The kernmantle rope was developed just for things like this - it's a very big safety deal.

The Dulfersitz is silly. I cannot imagine any situation where it's useful, as long as you have at least one carabiner. Heck, even if you don't have a biner.

OK, no biner, just a rope, gentle enough slope to Dulfer... I still wouldn't. If you can Dulfer, you can downclimb. Tie-in with a bowline or some kind of rope or webbing seat, and downclimb on a hip belay. Then the second downclimbs on a hip belay from below, running the rope around a tree or feature - whatever you would have rapped off if you'd dulfer'd.

But that's miserable. Bring a biner.
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Re: minimal carabiner for Munter rappel

Postby Augie Medina » Thu Feb 25, 2010 1:34 am

MoapaPk wrote: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.


Questions. How many people used your set up? How long was the rap? You obviously rapped on two strands. That sounds like a very bulky munter on that 'biner! How smoothly did the munter feed on the way down?

Assume you didn't have a rap ring so you threaded the webbing thru your anchor sling. How was the pull when you retrieved your webbing after the rap?

Re the dulfersitz. It's definitely only for low angle terrain.
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Re: minimal carabiner for Munter rappel

Postby MoapaPk » Thu Feb 25, 2010 2:24 am

Mountain Impulse wrote:Questions. How many people used your set up? How long was the rap? You obviously rapped on two strands. That sounds like a very bulky munter on that 'biner! How smoothly did the munter feed on the way down?

Assume you didn't have a rap ring so you threaded the webbing thru your anchor sling. How was the pull when you retrieved your webbing after the rap?

Re the dulfersitz. It's definitely only for low angle terrain.


Yesterday I was the only one who used the set-up. It was surprisingly smooth. The carabiner got warm, but then my atc gets warm. I was initially afraid it would be too smooth, as the webbing is quite slick.

I had a quicklink on the sling, and the pull was extremely easy. If I were not sick, I would have tried a ring, a smaller quicklink, then nothing; but alas, I was pretty exhausted after my short hike, 700' gain, and 2 raps.

The webbing didn't significantly twist, which surprised me; but because that carabiner design is so extreme, the 10/16 (but not the 9/16") webbing slightly warped; I don't know exactly how to explain it, but because the tubular webbing sides are not attached in the middle, one side moved slightly relative to the other, so there was a slight ripple noticeable after 2 raps.

On weight: for use as a handline, 13.5 mm (~9/16") and 15 mm tubular webbing are actually lighter than the same length 8mm rope -- at least according to my postal scale and the published weights per foot. Of course, webbing in no substitute for rope in many technical situations. But a 50' coil of this 13.5 mm weighs 6 oz, and handlines are really fast for setup. This is purely static stuff, with a rating of 4200 lbs and 2600 lbs breaking strength. (Sorry for the unit confusion; I wanted to make the comparison with rope a little easier, and Blue Water is going through a unit crisis.)

Again, this was just a test for a "what-if." I've seen where people with all the right gear... rapped off iffy anchors (some canyons in Death Valley... hmmm). So, there are times when things are not ideal, and I'd like to be prepared for such times. I'm not a climber, nor do I play one on TV.

Thanks again for all the probing comments.
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Re: minimal carabiner for Munter rappel

Postby RickF » Thu Feb 25, 2010 8:13 am

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...


For my edification, is a "body rapel" another term for the Dulfersitz?
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Postby dan2see » Thu Feb 25, 2010 3:29 pm

Moapa, you used the words "minimal" and "modest", and you say you do "3/4" hikes.

OK I scramble a lot, I know sometimes I wish for a rappel on the way down. Generally the rappel will be pretty short: we're talking hikes, not climbs. I often think about buying a "Rando" rope to do this.

But, if you need a carabiner, you also need a sit-harness. Your gear is adding up and up. You don't need either.

Instead, go for the body rappel. It's safe and easy. Although you better not be wearing short pants! !! !!!

Where I scramble, the natural anchors for a rappel are really poor, or non-existent. Except for pine trees. So for a tree, you'll need some sling webbing. But still no carabiner.

However, a rap on class 3/4 terrain kinda bothers me. It seems convenient at the time, but I suspect that it could be an unnecessary hazard in itself. So I always find another way around the drop-off.
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Postby MoapaPk » Thu Feb 25, 2010 5:17 pm

dan2see wrote:However, a rap on class 3/4 terrain kinda bothers me. It seems convenient at the time, but I suspect that it could be an unnecessary hazard in itself. So I always find another way around the drop-off.


Note I put "hike" in quotes. If you read this complicated, branching thread, you will see the scenario (real life) that produced the question. The best laid plans...
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Re: minimal carabiner for Munter rappel

Postby brenta » Fri Feb 26, 2010 1:53 am

MoapaPk wrote: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, I would. However, if hikers with little or no experience of rappelling were in the party, I'd feel much more relaxed with a locker than a wiregate. The Wild Country Neon is only 43 g. It is not an HMS, but it will do just fine in a pinch. The DMM Phantom screwlock is even lighter, though I'm not sure it's already available in the US. The new Petzl Attache is 55 g and is a true HMS. Other light lockers (also of the keylock type) have been mentioned earlier in the thread.

The Dülfersitz has been superseded by more comfortable techniques, just like it superseded earlier methods that would really make people cringe were they to have to use them. It is true that clothing was sturdier back then and ropes were thicker. That made a difference, but the idea that one could only descend low angle slopes ignores the history of climbing.
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Ring

Postby LithiumMetalman » Fri Feb 26, 2010 8:04 am

Long raps with a double munter can really heat up a biner, switching to a different biner after several blocks of rapping is recommended (the groove marks in my biners tell me), this even more so if rapping on a thin line.

I really recommend carrying two lockers (HMS style) and two non-lockers (Ovals).

In my experience HMS style / shaped biners tend to allow a smoother flow with a munter knot and tends to be gentler on the ropes kink wise. Also the larger basket allows for less fuss knot wise. It's really worth the extra weight for convenience / usability

I have used DMM Sentinels with much success (54g)


Image


2 ovals are quite useful, opposed they work just fine for munter rappels and belays. They also work quite well for carabiner brake rappels, utility biners, or leaver biners. the shape is great for reducing shifting when under load.

A sit harness can easily be made out of webbing. (Kinda comfy...lead falls blow in them though)

Maybe this is the young and stupid side of me speaking up :-) wouldn't it be alot faster, if not safer (at times), to just downclimb/slide/shuffle/skate/shoe ski/ fall down 3/4 class terrain rather than rapping? It would seem like one less thing to carry or futz with. Well...maybe aspirin...
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Re: Ring

Postby MoapaPk » Mon Mar 01, 2010 7:43 pm

LithiumMetalman wrote:Maybe this is the young and stupid side of me speaking up :-) wouldn't it be alot faster, if not safer (at times), to just downclimb/slide/shuffle/skate/shoe ski/ fall down 3/4 class terrain rather than rapping? It would seem like one less thing to carry or futz with. Well...maybe aspirin...


Thanks for the suggestions.

I ended up finding a HMS-type Petzl that weighs 55g, and is smooth-running (with a Munter) compared to my older BD offset D's.

As for why the rap was considered; you'd have to go back and see the specific description of the situation, earlier in this wandering thread. Briefly: unusual conditions covered the normal route (a traverse on ramps) in loose sand, and there was a 100' drop below the ramps. By backing up, we could have dropped about 30' down a dryfall.

Someone else suggested Connaly's book; at first I blew that comment off, but when I looked through the book, I really appreciated the suggestion. He has a lot of material on what people might do when caught with less than ideal gear, and his style is less dogmatic with a more modern viewpoint than in many classics.
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Re: Ring

Postby brenta » Tue Mar 02, 2010 3:30 pm

MoapaPk wrote:his style is less dogmatic with a more modern viewpoint than in many classics.

On the other hand, Connally strives more for effect than accuracy. For instance, on p. 116: "in a pulley system having a 3:1 mechanical advantage the puller feels one third and the anchors feel only two thirds of the load." This is true of the Z-pulley, but false of the Spanish Burton.

Or, on p. 147: "If two runners join at 30 degrees, moving the load from the perfectly equalized direction by only 10 degrees will result in three times as much force on one of the anchors as the other;" which, for a given spring constant, is only true for certain loads.

A few years ago he got a lot of flak on rc.com for some bold statements he makes about maximum forces in case of leader's falls. While I give him credit for reacting civilly to some harsh comments, he failed to address their substance.

On p. 120, he asserts that forces on the top anchor do not exceed 5 kN because beyond that the rope slips through the belay device. Then, on p. 122, he admits that in certain conditions the rope may not slip through the belay device, but he does not revise his quantitative claims. The inexperienced reader is actually led to believe that leading on static rope is as safe as leading on dynamic rope.

These unwarranted generalizations suggest a little caution when approaching Connally's Mountaineering Handbook to learn safe practices.
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Postby Autoxfil » Wed Mar 03, 2010 2:15 am

I understand what you mean - but if you read the whole thing, he's very clear. It looks to me like he never assumed anyone would cherry-pick that section.

Yes, with a safety system like this he might have been better off adding "(but not really - read the next section for more)" after he states that the top anchor only sees 5kN.

But, the next section is entitled "Real-World Influences on Fall Forces", and I know as I read it I was interested to hear the rest of the story. Who is going to read the first section, put the book down, and go take a whipper onto a micronut?

About the book in general:

Although I find myself agreeing with him so often that I want to do everything his way, I've decided that carrying my rope in a bag sucks. I've decided he's wrong about the bowline as a tie-in: he preaches security, but then doesn't consider that factor when picking a tie-in. Now, I learned the bowline and have used it to tie in when I had one hand - his method rocks. But when I have two hands? Re-trace and backup.

I'm rambling. It's a fine book, even exceptional - but some of the qualities that make it refreshing also bring flak. Read it, think about it, and add it to your sum of knowledge. That's what I like about it - he explains WHY, and then you can decide if that makes sense for you.

That process of deciding for yourself, based on facts, is great - I climb with an AMGA guide, and he does some things because AMGA does them. That bugs me terribly. Connally says to use pulleys and gives the numbers to back it up. AMGA says only noobs carry pulleys, with nothing behind it. AMGA says equalize and then tie off to limit extension. Connally says screw extension, and the science backs that up.

With softshells or training or stoves - screw it, why argue? But when it's the anchor we're going to hang on... science, please.
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