Double Fisherman's Unsafe?
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I recently heard something interesting from a climbing partner. He was told that the AMGA discourages using double fisherman's to tie runners/prusiks out of cord, and that two overhands (EDK with backup) are preferred. |
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I think you may have runner/prussik mixed up with making a bend with two ropes. My understanding is the EDK is best for joining two ropes in a double rope rappel although the double fisherman's is fine for that as well only that the fisherman's knot has a tendency to get caught when pulling the ropes. I use a double or triple fisherman's knot with cord that I tie in a loop for anchors that I top rope with, also on cord that I tie in a loop for autoblock. I believe a fisherman on webbing is called a grapevine but I could be wrong. |
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Yet another AMGA rumor... |
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It has nothing to do with safety. The Dub Fish is a great way if not the most secure way to tie two ends of rope or cord together. The problem is it's too secure and after being weighted will not untie. If you needed to unloop your cordellete to let's say replace a rap anchor, you would have to cut the dub fish out. You loose nothing by using a flat overhand and will be able to later untie it. |
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The double-fisherman knots should not be used to join webbing, but it is ideal for cord. The flat overhand (follow-thru) is applicable to nylon tubular webbing, whereas it is not ideal for cord. It is not advisable to join dyneema with any knots. |
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timinthehouse wrote:I think you may have runner/prussik mixed up with making a bend with two ropes.That's the only thing I could think of when I heard it. However, how this all happened was my climbing partner was climbing with someone else. The other climber took all his cord runners and retied them because he said the the AMGA recommends EDK and backup over the double fisherman's. My partner and I are both pretty sure this other guy is wrong, but I just wanted to see if anyone actually had source material to backup the claim. |
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Please everyone, stop referring to the flat overhand knot as a EDK (euro-death-knot), as that name implies an unsafe connotation and leads new climbers to tie their ropes together with a flat figure-eight knot, which rolls apart more easily and has led to 2 deaths in the US this year alone. There are many knots, some are more right than others, and some will kill you. |
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OP, here's a reference to exactly what you're asking. I don't love the article, but it references your question exactly. |
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As mentioned, the double (or triple) fisherman's knot is recommended for joining two tails of a cord together to make a loop. The double overhand (EDK) is for joining two different ropes for a rappel. The double fisherman's can be used for this, but it is a) difficult to untie, and b) more likely to get stuck in cracks, which is why the AMGA recommends EDK. |
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EDK is great for rap ropes. stupid as shit for a cordelette that you want to be able to use in situations that may have much higher fall factors than rapping. |
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Hard Data: user.xmission.com/~tmoyer/t… |
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We need to have a sticky knot thread with photos and brief descriptions of applications. Somebody more knowledgeable than I should start it. |
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George W wrote:Hard Data: user.xmission.com/~tmoyer/t… It's an easy google search, and the third result following two threads about this very subject...Thanks for posting that. I was never really concerned about the strength of either knot, more just curious about the claim that the AMGA would discourage the use of the DFK. Based on everyone's replies, as well as this data, is seems as though the AMGA has never discouraged the use of DFK's for the use of looping cord. Thanks for the fast replies everyone! |
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George W wrote:The double-fisherman knots should not be used to join webbing, but it is ideal for cord. The flat overhand (follow-thru) is applicable to nylon tubular webbing, whereas it is not ideal for cord. It is not advisable to join dyneema with any knots.you can use a double fisherman's knot with webbing. it is hard to untie though. for this reason, it is actually better to use the DF if you are leaving it as a rap anchor. it won't work loose over repeated use, which can happen with water knots. in general, i use edk when i am rapping, retraced 8 (flemish bend) if i am leaving up a TR for a bunch of folks, double/triple fishermans in cord or webbing that i am leaving as a permanent/semi-permanent installation. |
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Agree with the untie comment. The spool of my 5mm tech cord specifically states to use the dub fish. |
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A. Michael wrote:We need to have a sticky knot thread with photos and brief descriptions of applications. Somebody more knowledgeable than I should start it.Here you go: animatedknots.com/indexclim… |
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FourT6and2 wrote: Here you go:awesome. |
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I can't speak for the entirety of the AMGA, but as a general rule, the AMGA as a body does not take stances on specific technical systems and their uses. Rather, the AMGA encourages its guides to be knowledgeable about a wide number of technical solutions to various climbing problems and select the solution most appropriate for the application at hand. |
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I'd echo what Derek said. In general whenever some one starts a saying with "the AMGA says..." there was probably a misunderstanding somewhere. |
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Often, a cordelette is made more useful and versatile when it can be untied.
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