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runnit
Aug 20, 2008, 1:00 AM
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Here's a question for any vertical rescue gurus after me and a couple mates were talking on the weekend. It's focused on a BASE jumping rescue, but I figured climbers would have a greater wealth of knowledge about this sort of thing.
Say someone has had an offheading opening and is hung up on a cliff, you have enough sections of climbing rope tied together that you can rap down to them and then reach the ground, but you will need to do at least one knot bypass in order to get them down. They may or may not be injured/conscious. The rock doesn't allow gear to be placed to do a multipitch rap so you've only got the single rope to descend on.
The casualty will be wearing some sort of harness (their rig) but won't have any rope or other gear. The rescuer will be at the top of the cliff on the exit point with what ever gear is needed.
Does anyone know of a good way to do a knot bypass when you've the weight of two people hanging from the one belay device? What specific gear would you recommend (eg 5 bar rack vs a belay tube or something)? How would you attach the casualty to the rescuer?
The method I know for doing a bypass (for 1 person) involves lowering on to the belay device below the knot with a prussic and a mariner's knot, but this would be kind of dodgey with the weight of two people due to strength of a piece of 6mm cord and also just trying to release the mariner's knot under control with the extra weight.
Any ideas?
BJ
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Chappy76
Aug 20, 2008, 1:45 AM
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Depending on how injured the person is or if they are unconsciousness or not, it might be easier to have them ascend back to the top. What makes this situation worse is how you stated you can't do a multipitch rappel. Anyone else want to chime in? I would like to know as well. Now would a stokes litter be available?
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shoo
Aug 20, 2008, 2:39 AM
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Got it.
The set up:
Tie the person into a 3-5 foot length of rope (or parachute line) and clip the other end to the rappel device with a locking carabiner. I will refer to this line as the rescue line. You will be connected to the belay device via a single length sling which is similarly extended from your harness. This effectively gives you an extended rappel. Back this up with the usual leg loop autoblock. See below link for extended rappel setup.
http://www.chockstone.org/...Tips/RapBackup2l.jpg
1. As you approach the knot, the victim will pass it before you do.
2. After he/she is past the knot, stop the rappel with your prussik.
3. Mariner's hitch the victim directly to the rope below the knot.
4. Back the victim up by tying a figure 8 on a bight on the rope below the victim and clipping this to their harness.
5. Unclip the rescue line from the rappel device.
6. Rappel past the knot, using whatever method you prefer.
7. When you are past the knot, lock off your belay.
8. Tie the rescue line a little shorter so it can clip into the rappel device without slack.
9. Clip the rescue line into the belay device.
10. Release the mariner's hitch.
11. Finish the rappel.
In theory, you should never have a prussik or a mariner's hitch take more than one person's body weight at any time.
(This post was edited by shoo on Aug 20, 2008, 2:43 AM)
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moose_droppings
Aug 20, 2008, 2:43 AM
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So you've already picked off the dude and your just rapping past a knot with him hanging off you?
Rap down to just above the knot, tie an alpine butterfly a ways below where the knot is to create a loop (if you didn't already do that when you tied the 2 ropes together). Clip into the loop and rest on a prusik rigged above your belay device and connected to your harness. Hanging from the harness and backed up to the loop, undo your belay device and set it up below the knot. Rig your second prusik as an autoblock below the belay device. Unclip the loop than step into the loop with both legs, standing up to unweight your top prusik, putting your weight back onto the belay device with it autoblocked. Untie your loop and finish the rap.
Both of my prusiks are 7mm and wouldn't think twice about the extra hanging weight. Most SAR's would probably be using 8mm prusiks. I would think you could easily lift your weight and another persons with both legs.
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stymingersfink
Aug 20, 2008, 2:57 AM
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runnit wrote: Here's a question for any vertical rescue gurus after me and a couple mates were talking on the weekend. It's focused on a BASE jumping rescue, but I figured climbers would have a greater wealth of knowledge about this sort of thing. Say someone has had an offheading opening and is hung up on a cliff, you have enough sections of climbing rope tied together that you can rap down to them and then reach the ground, but you will need to do at least one knot bypass in order to get them down. They may or may not be injured/conscious. The rock doesn't allow gear to be placed to do a multipitch rap so you've only got the single rope to descend on. The casualty will be wearing some sort of harness (their rig) but won't have any rope or other gear. The rescuer will be at the top of the cliff on the exit point with what ever gear is needed. Does anyone know of a good way to do a knot bypass when you've the weight of two people hanging from the one belay device? What specific gear would you recommend (eg 5 bar rack vs a belay tube or something)? How would you attach the casualty to the rescuer? The method I know for doing a bypass (for 1 person) involves lowering on to the belay device below the knot with a prussic and a mariner's knot, but this would be kind of dodgey with the weight of two people due to strength of a piece of 6mm cord and also just trying to release the mariner's knot under control with the extra weight. Any ideas? BJ
The mariner's knot is somewhat more time consuming to set up than a munter+mule, though both of these should work fine with the kind of loads you're talking about. I wouldn't worry too much about utilizing the six mil cord, since it will be either tied in a loop (for the prussic or klemheist friction hitch) or double-stranded (as for the mariner's hitch). It would be easy enough to double up the strands for the munter+mule as well. I wouldn't worry about long-term durability of the cord (like I would if I were on a big wall climb) since it's pretty much use once and destroy.
Key would be to make sure you start down the raps with enough equipment to do the job. Minimum to my thought process is three lockers and several meters of 6mm cord, cut into a 60cm length (to be tied into a loop for the prussic or klemheist) and the remaining to lower past the knot with.
You can use one of the lockers to rap on with a munter.
One locker will attach your buddy to your harness somewhere secure
One locker will clip to the prussic to attach the munter or mariner's hitch to in order to facilitate lowering past the knot.
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epoch
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Aug 20, 2008, 11:45 AM
Post #7 of 48
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This thread should get interesting once majid finds it... 
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Aceto
Aug 20, 2008, 1:03 PM
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runnit wrote: Here's a question for any vertical rescue gurus after me and a couple mates were talking on the weekend. It's focused on a BASE jumping rescue, but I figured climbers would have a greater wealth of knowledge about this sort of thing. Say someone has had an offheading opening and is hung up on a cliff, you have enough sections of climbing rope tied together that you can rap down to them and then reach the ground, but you will need to do at least one knot bypass in order to get them down. They may or may not be injured/conscious. The rock doesn't allow gear to be placed to do a multipitch rap so you've only got the single rope to descend on. The casualty will be wearing some sort of harness (their rig) but won't have any rope or other gear. The rescuer will be at the top of the cliff on the exit point with what ever gear is needed. Does anyone know of a good way to do a knot bypass when you've the weight of two people hanging from the one belay device? What specific gear would you recommend (eg 5 bar rack vs a belay tube or something)? How would you attach the casualty to the rescuer? The method I know for doing a bypass (for 1 person) involves lowering on to the belay device below the knot with a prussic and a mariner's knot, but this would be kind of dodgey with the weight of two people due to strength of a piece of 6mm cord and also just trying to release the mariner's knot under control with the extra weight. Any ideas? BJ
Beginners sit and take notes I will say this once.
the mariners knot is inappropriat in this application.
regular tube style devices run the potential to jam prussik backups. a five bar rack is safer with friction variable.
many climber been rescued with inadequate rap gear
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j_ung
Aug 20, 2008, 1:09 PM
Post #9 of 48
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runnit wrote: The method I know for doing a bypass (for 1 person) involves lowering on to the belay device below the knot with a prussic and a mariner's knot, but this would be kind of dodgey with the weight of two people due to strength of a piece of 6mm cord and also just trying to release the mariner's knot under control with the extra weight. Any ideas? BJ
That's almost exactly the way I would do it, except with Muenter-mule hitches instead of mariners. Bear in mind, my perspective is that of a climber, not a professional rescuer.
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fresh
Aug 20, 2008, 1:23 PM
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I'm totally confused. does your rope descend the entire cliff and meet your jumper halfway? do you need to build another anchor at his position and set up another rappel? or do you intend to reach the jumper and then ascend the rope you just rappelled?
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epoch
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Aug 20, 2008, 1:32 PM
Post #11 of 48
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[opinion]
A Load Releasable Hitch - Mariner knot - is a tool that is often used in rescue applications because it provides redundant control. I think people are confused with the mule knot methodology and how it would be employed in this situation.
Passing a knot is passing a knot regardless of the situation.
Runnit, you already answered the question in your post. Your mention of using a 6mm chord makes you uncomfortable. Why are you not then using an 8mm chord instead? My knowledge of rescue systems is a bit rusted, having not used them for some time, but it seems prudent to maintain the beefieness and overkill that is found throughout the SAR communities in the US. I assume that you already understand and practice the standard method of passing a knot under tension. Why not then beef up your system to be stronger?
Also, if you are in that situation, it might be easier and better controlled if you were lowered into the scene, leaving the knot passing to a belay crew at the top of the cliff. This would allow you to maintain control of your victim and allow you to have two hands free to attend to thier needs.
[/opinion]
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Aceto
Aug 20, 2008, 1:37 PM
Post #12 of 48
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^ correct response.
things m ay be good enough for a given application but in climbing its best to be on the side of overkill.
many accidents in rappel could have been prevented using some form of fricktion wrap as a safety back up.
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j_ung
Aug 20, 2008, 1:44 PM
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This isn't a rappel accident.
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Aceto
Aug 20, 2008, 1:44 PM
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clarrification
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Aceto
Aug 20, 2008, 1:47 PM
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no passing the very knot that provides a margin of safety is dangerous. look up NAAM for rappelling of the ends of ropes. appropriate equipment is needed to eliminat dangerous variable.
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j_ung
Aug 20, 2008, 2:40 PM
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The question is about passing a knot with the weight of two people. I'm not sure why you're convinced rapping off the ends of ropes is the OP's issue.
Do I know you?
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stymingersfink
Aug 20, 2008, 2:46 PM
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j_ung wrote: The question is about passing a knot with the weight of two people. I'm not sure why you're convinced rapping off the ends of ropes is the OP's issue. Do I know you?
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marde
Aug 20, 2008, 3:12 PM
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Easiest way is I think to lower the rescuer.
Use a munter hitch for that and connect the ropes with a edk.
The edk passes through the munter.
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j_ung
Aug 20, 2008, 3:23 PM
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stymingersfink wrote: j_ung wrote: The question is about passing a knot with the weight of two people. I'm not sure why you're convinced rapping off the ends of ropes is the OP's issue. Do I know you?That's the $64K question, isn't it?
Not any more it isn't. aceto = majid_sabet. I am 100% certain of this. Or did you pretty much already figure that out? 
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chadnsc
Aug 20, 2008, 3:29 PM
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Yup, only one person on this site has that pre-pubescent, I have no self worth so I’ll try and make fun of everyone else style of writing and that's our favorite Midget.
Damn Midget even as a troll you come up lacking. I would have expected more from him.
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j_ung
Aug 20, 2008, 3:38 PM
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The big tip off was how, in this thread, he completely misunderstood what we were all talking about and all but called us n00bs for it. The clincher was when he sent me a PM telling me he expected better from me. Classic Majid MO. Add this from another thread:
Aceto wrote: listen u stupid nitwit come to my backyard u be my new RC.com gf. i do not play games with vermin like you. nothing but naysaying. how much time have you invested in understandign complicated rope managment?
And it's a no-brainer. Nobody can keep up a troll persona indefinitely. Not even drkodos could do it, and he was the best.
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epoch
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Aug 20, 2008, 3:41 PM
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j_ung wrote: stymingersfink wrote: j_ung wrote: The question is about passing a knot with the weight of two people. I'm not sure why you're convinced rapping off the ends of ropes is the OP's issue. Do I know you?That's the $64K question, isn't it? Not any more it isn't. aceto = majid_sabet. I am 100% certain of this. Or did you pretty much already figure that out?
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j_ung
Aug 20, 2008, 3:44 PM
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So who do you 98% think it is? Support your assertion, or I have no choice but to stand by mine.
(This post was edited by j_ung on Aug 20, 2008, 3:45 PM)
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majid_sabet
Aug 20, 2008, 4:24 PM
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j_ung wrote: So who do you 98% think it is? Support your assertion, or I have no choice but to stand by mine.
Jay
RC checks IP addresses on regular bases and they know who is who. one time, they almost ban a friend of mine in Yosemite cause i logged in from the same computer as bunch of other climbers do but then he explained the situation and he was allowed to log in. I have only one user name in this site or any other climbing site but I do log in from other places in California.
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