Fast passing of the knot for rappelling or lowering
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Some time ago, while considering self-rescue scenarios involving passing a knot on a regular rappel or a tandem or counterbalanced rescue rappel, or when lowering a partner, I realized that it is quite straightforward to get an EDK knot to pass through a loose munter, even from a distance. The only obstacle to the full passing of the knot is the munter's loop wrapping over the knot just as it exits the hitch and staying hooked there so that letting more rope through just keeps extending the loop. With a loose munter, the EDK can be easily released from this loop with a bit of shaking. |
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Man, that was long! I got through about three paragraphs. Maybe the next reader will do better. |
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If I was in a situation where i was rapping with a munter for self rescue it would be ideal to back it up with a prusik as well, but when doing so for a munter rappel where the brake hand is up the difference I would imagine is instead of a third hand your prusik is on the load side so if I was in a situation where I handt read on it and had to do it myself thinking through with what I have, I would go down to EDK, stop and load the prusik, feed the knot through with one hand on the brake strand ready to cinch it up if needed if the prusik starts to slip, which is shouldnt but you know just be ready in case. |
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My gut feel is that dealing with the coils introduced by rapping / lowering someone on a munter is not worth any ease of being able to pass an EDK through the munter - just my opinion. |
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Ryan Knowlton wrote:If I was in a situation where i was rapping with a munter for self rescue it would be ideal to back it up with a prusik as well, but when doing so for a munter rappel where the brake hand is up the difference I would imagine is instead of a third hand your prusik is on the load side ...Interesting alternative. The point of this thread is, of course, to add useful and fast knot-passing tools to the self-rescue toolbox. Looking only at the knot-passing on rappel, your method has a certain appeal and would probably go about as fast as mine. Your step-up prusik would become the new load-side back-up for the next part of the rappel so it appears to be quite economical in prusik-installations and take-downs, which are time-consuming steps in the more standard knot-passing procedures. However, you may want to test your premise that in a rappel on a munter, you would keep the brake strand side-by-side with the load strand. That is indeed how you get the most friction out of a regular munter, which is essential for lead belaying, but for rappelling, keeping the two strands together is not practical. Braking downward reduces friction but there's plenty enough left to hold body weight and it allows easily stopping and restarting the rappel using an ATC-style 3rd-hand. Depending on the situation, you may need to do this more than once before getting to the knot. With your system, you would need to have a way to do this that avoids loading the back-up prusik. I don't really see any other option than the mule-overhand (or similar) block if the brake strand it to be kept in the upward hold. However, having to install and undo this block at each stop would be quite time-consuming. The other disadvantage is that, in certain self-rescue rappel situations, stepping up on anything, be it a foot hold, a prusik sling, a rope loop, etc. may be quite out of the question. Finally: keeping load and brake strands together is a useful position for belaying a partner on a direct munter belay, whether he's climbing or getting lowered, and, in this position, a brake-strand 3rd hand works really well. In this case, sticking with your plan of having a load-side prusik take the weight to be able to pass the knot easily (in this case, transferring the weight to the anchor) would involve installing and undoing a separate PMMO, which would be counterproductive. |
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jktinst wrote:Interesting alternative. The point of this thread is, of course, to add useful and fast knot-passing tools to the self-rescue toolbox.One possibly useful trick when just one knot is involved: In this method, first person does not need to pass the knot on rappel. And, in ideal circumstances, no one but the last person need pass the knot on rappel. While at the rap station: a) person A - about to go down - rigs their rap device just below the knot and ties it off; b) other person B rigs their device just above the knot; Then: c) person B lowers person A until out of rope; d) person A then releases his / her rap device and continues on rappel. Probably good for person B to have a plan for keeping the lower excess rope under control. |
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I didn't real the long OP. But I understand that knot passing is pretty routine, as evidence by the various British and AMGA test scenarios. No need to re-invent anything. |
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passing the knot is pretty simple if you practice it enuff ... |
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bearbreeder wrote:passing the knot is pretty simple if you practice it enuff ... there are tips and tricks to make it easier ...You're usually more generous with relevant information. Would you please provide descriptions or links for these tips and tricks for everyone's benefit? bearbreeder wrote:... be VERY careful about super long tails on rap ... theres been a case or two where someone setup a rap on a "tail line" and rapped right offThis would be much more of a risk with the "munter pop-to-munter" knot pass and with most of the standard knot-passing techniques than with the "EDK munter pass-through". With the "pop" and other methods, you need to install the rope brake (munter, ATC, etc.) on the second rope and transfer to it. Therefore there is a possibility that you might install it on a long tail instead of the second rope. With the EDK pass-through, you stay on the same primary munter throughout the whole rappel or lowering, past knots and onto successive ropes. Not only do you never undo this munter or come off its biner until you're completely finished, but you don't even undo the second munter either so there is no risk of undoing the wrong munter by mistake. You install the second munter and when you're done with it and are resuming the descent after passing the knot, controlling that descent with the primary munter, you just let go of the second one and let the knot simply pull it out of the biner. There's no chance either that you'll get to that point at the end of the procedure confused about which munter to let go of. The primary munter will be the one with the 3rd-hand autoblocking hitch. Where an error might have crept in is if you installed that second 3rd-hand on the long tail instead of the second rope to begin with. It would work as a braking strand at first and let you control your descent for a few more inches before the knot started passing through the primary munter and biner. However, your mistake would be obvious as soon as it did start passing. With each of the two passages of the knot through the biner, the tails are left trailing behind on the other side of the biner and you have to pull them out to proceed (another reason why you wouldn't want them super-long to begin with). With this mistake, you would see right at the first biner passage of the knot that you could only pull out one of the tails and couldn't proceed further. As this point, the hitch would still be functioning as a 3rd-hand, effectively blocking the munter while remaining easily releasable, so correcting the mistake would be quite straightforward. |
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With a munter lower you can force the knot through if the knot is small enough and the carabiner is big enough. |
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perhaps you can provide photos or diagrams of your system? |
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Gunkiemike wrote:I didn't real the long OP. But I understand that knot passing is pretty routine, as evidence by the various British and AMGA test scenarios. No need to re-invent anything.My general rule of thumb is that if a technique takes multiple paragraphs in multiple posts to explain and discuss, then it is not suitably simple enough to actually use in a real climbing situation. |
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This may simply not be helpful but I'll share anyway. |
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bearbreeder wrote:... the thing about the "standard" knot pass is that its more or less applicable to any knot passing situation ... there are times when you dont choose the "tails" but they choose you .... ie rapping down and you discover a core shot ... you need to isolate that loop right there, no tails ;)Yes, the standard knot-passing methods are an essential tool in all self-rescue toolboxes because they can work in most or all situations, with any knot, any brake, etc. I have outlined the conditions that would prevent the EDK pass-through from working but these conditions are easy to ensure from the beginning. Within those parameters, the EDK pass-through is fine for a simple rappel or a counterbalanced or tandem rappel with an injured partner, and for lowering a partner. Regarding the core shot situation, that normally calls for the rope to be cut sooner or later. With the standard knot-pass, there is no strong reason why it would need to be cut right there and then but if you have a good reason to use the EDK pass-through (more than one knot to pass, in a hurry, etc.), there is no reason NOT to cut it and make the two tails you need right away. However, if there are other situations when the EDK pass-through really will not work, I definitely would like to know about them. Rich zz wrote:With a munter lower you can force the knot through if the knot is small enough and the carabiner is big enough.This is funny. Were you trying to boil the OP down to a single sentence? Yes, that is the essence of the technique, except that, as I explained, under full body weight, you can't just pass the EDK through the munter. It catches on the munter's loop just after it's made its second pass through the biner and wrestling the loop off the knot can be quite hard. The intermittent weight transfer to the second munter that I describe makes this much easier. Marc801 wrote: My general rule of thumb is that if a technique takes multiple paragraphs in multiple posts to explain and discuss, then it is not suitably simple enough to actually use in a real climbing situation.I guess that you've never read a self-rescue manual because there's always way too much text explanation and too many diagrams and photos. Most, if not all self-rescue techniques take way (waaaayyyy) longer to describe and represent step-by-step for someone who's never seen it than they take to carry out once you know how to do them. But the point is that this is a discussion about a potentially new or previously known technique that may have flaws I have missed, not a self-rescue manual description of a well-established method. To practice this, or any other knot-passing method, it would obviously be best to have a set-up where you can easily step up about 3 m and rappel back down repeatedly (easy short route, tree & ladder, etc.). With this set-up, one shouldn't need more than 3-4 practice rappels to get to a point where the EDK pass-through takes them 25-30 sec. tops. For those who may be interested in and able to stomach text explanations, here is the detailed step-by-step procedure for a rappel. This can be easily transposed for lowering instead. - stop and block the main munter with the first 3rd-hand just before the knot (+ leg wraps or fig. 8 bight clipped to harness for an additional back-up if preferred) - install the second 3rd-hand on the second rope and block it - remove the first 3rd-hand - release the second 3rd-hand and allow the main munter to slide, letting (and helping, if necessary) the knot pass twice through the biner (pulling the tails to follow the knot on the first pass) - block the main munter again just as the knot exits the biner for the second time and as it starts catching the munter's loop - thread a second munter beside the main one with the long tail and block this second munter by hand - release the main munter until the weight is on the second one and the loop of the main munter is loose, then block the 3rd-hand again - pull the loop off the EDK and pull the short tail out of the main munter - cinch the main munter down on the biner and move up and block the 3rd-hand - let go of the second munter and tie the anti-inversion knot on the short tail - resume rappelling on the main munter, letting the second munter slide out of the main one, pulled by the EDK. Initially, I wasn't planning on doing diagrams or photos because I think that it's much simpler to just explain that you need to install two munters side-by-side on a large biner (one of which has a knot passing through it with tails sticking out) than to provide a "plate of spaghetti" illustration. Then I figured that I might be able to do it with schematic diagrams. I spent a good part of yesterday afternoon on them but then couldn't get my printer-scanner working so illustrations will have to wait a bit, sorry. |
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printer-scanner is fixed. |
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thanks for drawing it out ... maybe im STOOPID but i really dont see how it works under full body weight |
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I pass knot all of the time (for work). |
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bearbreeder wrote:... i really dont see how it works under full body weight ...I did at least 10 knot-passes on single-strand rappels with this technique when I tested it over Christmas, hanging from a tree branch, using the following rope/cord combinations: - 8.5 X 8.5 mm doubles - 10.3 X 10.3 mm (two ends of the same single rope) - 10.3 X 8 mm dynamics - 10.3 dynamic X 7mm static For the lowering, I did only 2 tests with the 8.5 X 8.5 mm combination (had trouble tearing a guinea-pig away from her cousins, or maybe it was from her cell/laptop/games console), lowering from a redirect anchor on the same tree branch, with the belay anchor at the base of an adjacent tree. The technique worked just fine under full body weight in all cases. bearbreeder wrote:...regardless the "standard" knot pass looks to be alot simpler ... not to mention it works with any device, biners and on dual strands ... and theres no need to step up if you use a releasable hitch with the friction knot ;) PosiDave wrote:...Why would you not just use a friction hitch? There are 100 other simple ways...Timewise, for me, the issue with the standard methods is setting up and removing a prusik solely for the weight transfer. While I like the hedden for a 3rd-hand, the only hitch I trust for full body weight and higher loads is the prusik, which takes longer to install, dress and remove than most other friction hitches. Installation of a 4-wrap prusik with a long cord sling takes me about 20 sec. Removing it after a full weighting and stowing it: about the same again, and then there's installing and letting out the MMO on the prusik sling as well. So for me, the EDK pass-through is somewhere between two and three times as fast as the standard method. But maybe that's just me. That's why I like the speed advantage of techniques that do not involve installing a PMMO for the weight transfer, like Rich's munter pop-to-ATC (or those described by Bill Lawry and Mathias, although they clearly have relatively limited applications). Saving 30-40 sec. on a knot-pass may not seem like much but when bringing back down an unconscious leader or bailing in a thunderstorm, every second counts. |
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A Klemheist or a Bachman work pretty damn well. |
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Klemheist or Hedden: same thing. In my experience, under full body weight, both stand a fairly good chance of binding themselves fast and be extremely difficult to loosen. A prusik may be a bit difficult to loosen but will never bind itself fast. And a Bachmann on a single strand of rope (say an 8.5 mm double)? Seriously? |