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Rappel Stuff


Blake

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If I'm climbing in the alpine using a long 9.3mmish rope and a 6mm static rap line to facilitate long rappels, is there anything wrong with rappeling only down the 9.4, but then have the 6mm running next to it, and using the 6mm to pull my rope down once I'm at the bottom? (I'd have to make sure there was a loop on my rap anchor with a hole smaller than the knot between the two ropes at the top, or have the second person secure the ropes above when I was going down, and then i'd need to secure them both at the bottom when they rapped.) I could even keep the 6mm in a pack and play it out as I descended per Lowell Skoog's idea here: http://www.cascadeclimbers.com/ubb/Forum9/HTML/000013.html

 

2. On Carabiner brake rappels, assuming you have a locker on your harness, does anyone just use two perpendicular oval or D carabiners for the "brake"? Is this considered a death trap because they aren't lockers or in pairs opposite/opposed? If you are using three, are you doubling up on the carabiners that are clipped to your harness locker?

 

 

3. I'f I'm cutting the 8mm Mammut slings (to tie around a tree for example) is a standard water knot the recomended procedure? Or is the width of these such that another knot is better?

 

-Blake

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3. I'f I'm cutting the 8mm Mammut slings (to tie around a tree for example) is a standard water knot the recomended procedure? Or is the width of these such that another knot is better?

 

Yikes! That's expensive. Take some regular webbing with you for leaver stuff. I would be pretty nervous about a waterknot in any dyneema/spectra sling due to it's slipperiness & thinness. Maybe a fisherman's would be better? I dunno.

 

RE: Q#1, If you trust the jammed knot not to slip through your anchor, it seems like it would be OK. However, having the 6mm through your device insures that it will stay close to you (i.e., you will be able to reach it), when you get to the end of the rappel. The only reason I can think of to not have the 6mm line through your device is to avoid tangling.

 

Re#2, I believe it is standard practice to use two oval or D biners as the "perpendicular" biners. The gates of those two biners should be opposite, but NOT opposed. If they were opposed, the rope would push open one of the gates. I've never tried using three biners, so can't comment on that.

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Re: the biner brake, the more biners, the more friction. it can be hard to control a one-biner biner brake setup like you describe. good way to make an uncontrolled descent.

 

agreed with pax cutting up a mammut sling is one of the dumbest things you could possibly do. not to mention cutting spectra without the special tool is rather difficult!

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I have a bunch of nylon slings, but I was planning on leaving them behind for alpine stuff. This was more of a "what if" question, not a "I plan to" question. Is the consensus that spectra/dyneema should not be tied?

 

As for the # of biners in the rappel, I know that the more carabiners you have, obviously the more friction you have. I don't weigh much, and on stuff <90 degree or without much of a pack, I was looking for the lowest # of carabiners (least friction) I can use and still be safe. All the pictures I see (and they way I was taught) use two sets of 2 carabiners, but I was hoping to get away with fewer.

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RE: Q#1, If you trust the jammed knot not to slip through your anchor, it seems like it would be OK. However, having the 6mm through your device insures that it will stay close to you (i.e., you will be able to reach it), when you get to the end of the rappel. The only reason I can think of to not have the 6mm line through your device is to avoid tangling.

 

 

I've heard that it's awful tough to manage a rappel of two different ropes (one dynamic one static) with a high% difference in diameters. A way around needing to manage both of them is what I was getting at.

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All the pictures I see (and they way I was taught) use two sets of 2 carabiners, but I was hoping to get away with fewer.

 

The 2 biners used as "break bars" are for the friction. The 2 biners used flat, have the gates positioned on opposite sides. They use 2 carabiners so that you wouldn't be side loading the gate on a single. Lockers are not much stronger than non-lockers for this type of loading. And 2 lockers used this way actually make this worse.

 

If you want to use only 1 biner, just twist the rope a few times around the solid side of the biner and rappel on that. More wraps more friction. It will twist the rope pretty bad though.

 

chris

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on #1, there was a tech tip in climbing about this a while back. I'll look for the picture, but essentially you tie the two ropes together as normal, then tie a fig-8 on a bight in the small rope and clip a biner through that and the larger diameter rope. it will jam on the anchor when you load the lead line, allowing you to rap on the single strand. just pull the tag line and you're set. it looks like it'd get hung up easily though since there's a biner on it.

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The biner coming off the harness can be either a locker or 2 ovals/d's. The next set (that is parallel to the harness biner) has to have 2. One biner for "brake bar" is just fine for ropes over 10mm. I get plenty of friction on my 10.5 at 175 lbs body weight.

 

Your question implies one scenario where you might use brake biners directly with a single locker. I don't think that's a good idea. Take a look at the explaination in FOTH7 on page 196/197. It's not bad.

 

Tie spectra with a tripple fishermans cause it's slippery. But don't cut your mammut slings!!!

 

I'm trying to picture in my mind your setup in the 6mm cord. So you've got an anchor with a loop that's not big enough to pass the knot through, I guess so you don't have to rely on the strength of the 6mm cord. There was a better method posted here a while back. Tie a figure 8 on a bight, then loop the rope through to make a slidable loop attached to the anchor. Then tie the 6mm cord into the figure 8 loop to use as a pull cord. I just wouldn't trust that the knot wouldn't slip through the anchor under weight, if I'm reading your first description right.

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I've heard that it's awful tough to manage a rappel of two different ropes (one dynamic one static) with a high% difference in diameters. A way around needing to manage both of them is what I was getting at.

 

Normally, it isn't tough. the skinny line will want to slip through your device faster than the fat one, so all you have to do is make sure the knot attaching your two ropes together is on the skinny rope side of the anchor, then do a normal double rope rappel. You have to pull the skinny line at the end, which takes more effort, but since the fat line comes down last, it is less likely to tangle around every flake and bush. Of course, you can always rappel a la the tech tips describing a fig 8 on a bight clipped to the other rope, and its great for rapping with gri-gris, but gets snagged easy when you pull.

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I'm trying to picture in my mind your setup in the 6mm cord. So you've got an anchor with a loop that's not big enough to pass the knot through, I guess so you don't have to rely on the strength of the 6mm cord. There was a better method posted here a while back. Tie a figure 8 on a bight, then loop the rope through to make a slidable loop attached to the anchor. Then tie the 6mm cord into the figure 8 loop to use as a pull cord. I just wouldn't trust that the knot wouldn't slip through the anchor under weight, if I'm reading your first description right.

A Biner Block (short version - place biner through sling/rap ring, tie biner to rope, clip and lock biner around rope to form loop around main line. Tie thin cord to other line) Would work better.

 

If your interested in rappel setups, checkout some canyoneering pages. The spend lots of time figuring out different ways to rig raps. www.canyoneering.net, the American Canyoneering Association's page used to have good info, but I can't find it now.

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RE: Q#1, If you trust the jammed knot not to slip through your anchor, it seems like it would be OK. However, having the 6mm through your device insures that it will stay close to you (i.e., you will be able to reach it), when you get to the end of the rappel. The only reason I can think of to not have the 6mm line through your device is to avoid tangling.

 

 

I've heard that it's awful tough to manage a rappel of two different ropes (one dynamic one static) with a high% difference in diameters. A way around needing to manage both of them is what I was getting at.

This is right out of my butt, but just a thought: If you're worried about managing two different ropes in your rap device, and want to keep the 6mm line close you you, can't you just run it through a carabiner on your harness out of the way?

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my recollection re: spectra/dyneema/other slippy nylon is that the manufacturers recommend a triple fisherman's knot if you HAVE to tie them, but suggest you just don't do it. on using a skinny retrieval cord, i don't see a problem if you manage it carefully. people have been doing it for most of a hundred years; i'd call that a significant sample size. i found even using two biners as a brake with a skinny (sub 10mm) rope a fast ride, and i don't weigh all that much. i'm assuming it's a just in case question? i mean, why bother with a ten step setup that leaves more opportunity for error when there are such excellent rap devices on the market designed for skinny ropes (jaws, newer atc, etc.) that are easier to set up and double check for safety?

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It's still really good to know how to make a biner brake in case you lose your device. Biner brakes can be doubled up, provided you have enough biners. With a double biner brake you could rappel on a pair of 6 mm cords, such as your haul line, if that is all you had.

 

Munter uses no biners and works too! Every climber should know this knot!

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I have a bunch of nylon slings, but I was planning on leaving them behind for alpine stuff. This was more of a "what if" question, not a "I plan to" question. Is the consensus that spectra/dyneema should not be tied?

 

As for the # of biners in the rappel, I know that the more carabiners you have, obviously the more friction you have. I don't weigh much, and on stuff <90 degree or without much of a pack, I was looking for the lowest # of carabiners (least friction) I can use and still be safe. All the pictures I see (and they way I was taught) use two sets of 2 carabiners, but I was hoping to get away with fewer.

 

 

Most alpine climbs I have been on that are established have ways of getting down without leaving slings behind, walking off or using existing anchors. So you don't need to leave or carry that much slingage. Also if you are adding to an anchor do a little community service and cut out the old shit. Too much old slings left behind are just ugly.

 

So why would you risk jamming your knot in the anchor by rapping down a single strand versus rapping down both lines? I have never understood that one.

 

I have found one locking biner and rappel device is sufficent, except when the ropes are wet and icey. That is on skinny's too. Tie an autoblock system if you need a little security. Or other time times I will extend the device on a sling so that I can easily have both hands on the brake.

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bigdrink.gif Parker...I just had this funky dulfersitz-like image going, glad you cleared that up.

 

Ken, I'm not a fan of the autoblock on icy ropes, nor if the belay/rap device isn't extended a foot or two from the harnes.

 

A cool alternative someone showed me is to use the normal ATC/Munter/Carabiner brake, etc on the belay loop and then add a 2nd friction point on a carabiner hooked to a leg loop. I find a munter works well at that point and adds a ton of friction when raping on skinny, wet, or icy ropes.

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I think putting the munter on my nuts would be less painful than the dulfersitzthing, ja! I never knew why those Austrian or Bavarian sweaters had leather patches on the shoulder and they wore leiderhozen (sP?) until I tried it once. Ye-ow!

 

I put my autoblock on my leg loop and make sure it can't reach and jam in the rappell device. It also helps to have a quiver of belay devices sized to match your ropes.

Edited by David_Parker
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I put my autoblock on my leg loop and make sure it can't reach and jam in the rappell device. It also helps to have a quiver of belay devices sized to match your ropes.

 

A friend of mine experienced the scary consequence of what happens when the autoblock on legloop DOES reach the ATC and fail to 'lock'. IMHO, if you're going to use the autoblock it pays to extend the belay device away from the harness at least a foot to prevent this. A spectra sling (or 2) like we all carry is ideal for this use.

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