Some questions about the Biner Block rappel method
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I was reading a bit about the incident at Yosemite with the biner block rappel where the climbing party failed to use a carabiner clipped back on itself to backup the knot. I was reading about it and came upon an illustration in rock and ice that looks like it would have a higher potential of getting stuck. Check out the link and tell me what you think please |
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Well the fig 8 on a bight that the carabiner is clipped to could still get pulled through some larger rap rings and you'd have the same problem of not being able to pull the ropes. |
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Bryan Gohn wrote:Well the fig 8 on a bight that the carabiner is clipped to could still get pulled through some larger rap rings and you'd have the same problem of not being able to pull the ropes. The only way I can think of to get around that would be to clove hitch the rope onto the spine of a carabiner and let that be what jams up against the rings.If you tied a tight 8 (say only big enough to fit the carabiner through the loop) the entire knot probably wouldn't pass through the rings. The clove hitch sounds good but you're going to be cross loading the carabiner then (with what little force it would see). |
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Wouldn't your knot on a bight be the same size as the Euro they were using, so would pull through just as easy and get stuck? |
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In any case, your suggestion would be better than the example on Rock and Ice just because the backup is on the full strength rope, not some 6mm line (that you didn't trust enough to rap on in the first place). |
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Eric Krantz wrote:Wouldn't your knot on a bight be the same size as the Euro they were using, so would pull through just as easy and get stuck? Why not bring a slightly bigger rope and rap on both strands?The problem with the rock and ice image is the knot joining the ropes is in front of the knot with the carabiner. Does that make sense? If your knot with the biner is in the climbing rope alone and it's in front of the knot joining the ropes it would be less prone to getting stuck I would think and it couldn't pull very far (depending on how small of a knot you tie- smaller = better) because it would have the biner attached to it with your weight on the other side. How common of a problem is rope hangup with this method? The reason I brought this up is I'm still unsure whether or not I want to just rap with two ropes and get a 8.4mm as a rap line or get something around 7 (a twin line maybe for ice?) to just use as a pull line. |
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Yes, that makes sense now. But there would still be that one inch between the knot and the carabiner? |
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Nick Mardirosian wrote:The clove hitch sounds good but you're going to be cross loading the carabiner then (with what little force it would see).A biner block is extremely common amongst the canyoning/canyoneering crowd. They use it way more than a knot block. |
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Anytime you add knots or bulk to the system, you increase the odd of getting a rope stuck. |
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Getting ready to head to red rock, and doing what I can to avoid carrying two ropes on some of the longer approaches. I have done a lot of canyoneering and have no hesitation doing single rope rappels. I brought this website up to share with my partner and figured people may like a refresher (with a picture) thanks to Tom Jones and CUSA canyoneeringusa.com/techtip… |
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The alpine butterfly is a knot that won't get jammed in the rings as easily as an 8. After much research and input from the forums here that is definitly the concensus: alpine butterfly for the carabiner knot as its proven to not jam as much (if at all). |
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Calvin Laatsch wrote:Getting ready to head to red rock, and doing what I can to avoid carrying two ropes on some of the longer approaches. I have done a lot of canyoneering and have no hesitation doing single rope rappels. I brought this website up to share with my partner and figured people may like a refresher (with a picture) thanks to Tom Jones and CUSA canyoneeringusa.com/techtip…+1 I've used this type of setup many times for descending canyons with one rope and a skinny pull line. The knot or biner block is not likely to jam in the rap rings with the setup shown above. There is a a lot of great info like this on Tom's webpage! |
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Dana Bartlett wrote:That's a nice link to the canyoneering site; thanks. What is the joining knot?I can see an EDK but it looks as if there is something else there, too.Dana, I think that's an EDK on top of an EDK. If I was going to to that, my preference is a FLAT double fisherman's. |
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"Getting ready to head to red rock...." |
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Sarugo wrote:""I think that's an EDK on top of an EDK" The second EDK that is snug up against the first one is to keep it from rolling under really heavy loads.Yes. And in this case, kind of overkill for just a pull line. But then, so is my flat double fisherman's - LOL |
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It's not overkill for a pull line if you absolutely need your rap line. If your ropes separate you're not getting that pull line because you blocked it. It is safe to ascend though (provided your anchor was a decent one). |
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Calvin Laatsch wrote:Getting ready to head to red rock, and doing what I can to avoid carrying two ropes on some of the longer approaches. I have done a lot of canyoneering and have no hesitation doing single rope rappels. I brought this website up to share with my partner and figured people may like a refresher (with a picture) thanks to Tom Jones and CUSA canyoneeringusa.com/techtip…I use a 7mm pull line for this & one thing I highly recommend is the rope bag for the pull line, without it the pull line blows all over the place & wraps itself around your rope (and everything else it can find). I've tried a few different bags, the thing I like the best is a large "Chico" reusable grocery bag. They have large handles you can loop around your knees while you stack the line in, even works at a hanging belay. When I rap I just clip the handles to my gear loop & the line/rope feeds out as I go. They weigh next to nothing, compress to a few cu. inches, cost about $7, and will hold my 70M Mammut Infinity. I carry two with me for long raps and they save a great deal of time with rope management. The ordinary $1 reusable grocery bags you'll find at Albertson's (& other Grocery stores) work OK too, but they don't compress as tightly, and if you get them wet they stay wet longer. |
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GLD wrote:It's not overkill for a pull line if you absolutely need your rap line.OK. It's good to to know that we routinely trust an EDK to connect two ropes when rapping on two ropes but it's not overkill and we need something far more secure for a pull line. GLD wrote:If your ropes separate you're not getting that pull line because you blocked it.And, if the ropes your rapping on when rapping on two ropes tied with an EDK separate, you die. Yet we trust the EDK for this. Just not for a pull line. GLD wrote:It is safe to ascend though (provided your anchor was a decent one).errr.. I have no idea what you mean here. What you typed sounds like you're saying it's safe to ascend the pull line. |
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Calvin Laatsch wrote:Getting ready to head to red rock, and doing what I can to avoid carrying two ropes on some of the longer approaches. I have done a lot of canyoneering and have no hesitation doing single rope rappels. I brought this website up to share with my partner and figured people may like a refresher (with a picture) thanks to Tom Jones and CUSA canyoneeringusa.com/techtip…It is safer to thread the white and orange rope through the figure eight. If a climber does not thread the pull-line and the knot pulls through, s/he is dead. If the climber does thread the pull-line, the chance of the knot pulling through is much lower. I know you used a carabiner block, but you wouldent need to use the block (in some cases) if you threaded the pull-line. In short, there is no real reason that I am aware of as to why climbers should not thread the pull-rope. |
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wivanoff wrote: Yes. And in this case, kind of overkill for just a pull line. But then, so is my flat double fisherman's - LOL The knot is two overhands back to back. It is possible that one overhand can flip right off the end of the rope however unlikely. The setup is used with and without the biner block so its just habit to tie it as if you were doing a double rope rappel. As for the crossloading of the biner that is not the case. You are crossing two inches of the spine against a rap ring which is completely different than weighting a biner which is actually loaded from above and below in a sideways fashion. One thing to watch with a biner block with a clove hitch is make sure the biner cannot fit through the rappel ring. People have died because the biner rotated before it was weighted and slipped right through (like a bad knot block). |
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wivanoff wrote: OK. It's good to to know that we routinely trust an EDK to connect two ropes when rapping on two ropes but it's not overkill and we need something far more secure for a pull line. And, if the ropes your rapping on when rapping on two ropes tied with an EDK separate, you die. Yet we trust the EDK for this. Just not for a pull line. errr.. I have no idea what you mean here. What you typed sounds like you're saying it's safe to ascend the pull line.I'm guessing from your extensive use of sarcasm you don't get out much with other people otherwise most partners would ditch you. I routinely place a knot above the EDK even when rapping and it's recommended by most people. Reading pull tests it does increase the safety slightly. EDK earned the undeserved reputation and stands for european death knot. The rolling issue is worse with dissimilar sized ropes. My comment regarding the separation is that while pulling if the ropes separate your pull line will come down but your rap line will not. You will have to jumar up your rap line and reset everything-though no big deal since it is blocked it is safe (assuming you aren't sawing it across a sharp edge while jumarring). Personally, I find ascending ropes tiresome and in long canyons quite bothersome due to the delay (I don't like finishing in the dark). |