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antigrav
Sep 7, 2006, 8:23 PM
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Recognizing that the knot(s) can be tied in two different ways, say "symmetric" and "antisymmetric", where one is definitely neater than the other, my question is; is one stronger than the other?
(Of course, maybe only the "neat" version is actually a fisherman's knot, in which case the answer to the question is much more important...)
Followup question: If tied as an abseiling knot, does the difference become more or less important, if it makes a difference at all?
http://bombadil.kicks-ass.net:8080/IMG_3764_small.JPG
http://bombadil.kicks-ass.net:8080/IMG_3765_small.JPG
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cintune
Sep 7, 2006, 8:51 PM
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The bottom one.
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rockguide
Sep 7, 2006, 9:08 PM
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In reply to: Recognizing that the knot(s) can be tied in two different ways, say "symmetric" and "antisymmetric", where one is definitely neater than the other, my question is; is one stronger than the other? (Of course, maybe only the "neat" version is actually a fisherman's knot, in which case the answer to the question is much more important...) Followup question: If tied as an abseiling knot, does the difference become more or less important, if it makes a difference at all? http://bombadil.kicks-ass.net:8080/IMG_3764_small.JPG http://bombadil.kicks-ass.net:8080/IMG_3765_small.JPG
Both pictured knots are SINGLE, not double fisherman's knots and aren't considered stable or secure enough to join two ropes for a rappel.
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antigrav
Sep 9, 2006, 10:24 AM
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In reply to: Recognizing that the knot(s) can be tied in two different ways, say "symmetric" and "antisymmetric", where one is definitely neater than the other, my question is; is one stronger than the other? ...
Nobody that knows the answer to this, or have any pointers or comments?
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timm
Sep 9, 2006, 1:56 PM
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Pull tests by the AMGA show that there is no strength difference for "symmetric" vs. "asymmetric" versions of the double fisherman knot.
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mturner
Sep 9, 2006, 3:42 PM
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In reply to: In reply to: Recognizing that the knot(s) can be tied in two different ways, say "symmetric" and "antisymmetric", where one is definitely neater than the other, my question is; is one stronger than the other? (Of course, maybe only the "neat" version is actually a fisherman's knot, in which case the answer to the question is much more important...) Followup question: If tied as an abseiling knot, does the difference become more or less important, if it makes a difference at all? http://bombadil.kicks-ass.net:8080/IMG_3764_small.JPG http://bombadil.kicks-ass.net:8080/IMG_3765_small.JPGBoth pictured knots are SINGLE, not double fisherman's knots and aren't considered stable or secure enough to join two ropes for a rappel.
Thank you! Had me second guessing myself about the double there for a minute
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rockguide
Sep 10, 2006, 12:23 AM
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I still had a turd flung at that post. Apparently someone disagreed.
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timm
Sep 10, 2006, 12:30 AM
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In reply to: I still had a turd flung at that post. Apparently someone disagreed.
How dare you give out accurate information. :wink:
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rockguide
Sep 10, 2006, 12:32 AM
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In reply to: In reply to: I still had a turd flung at that post. Apparently someone disagreed. How dare you give out accurate information. :wink:
I KNOW!
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antigrav
Sep 11, 2006, 6:42 PM
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In reply to: Pull tests by the AMGA show that there is no strength difference for "symmetric" vs. "asymmetric" versions of the double fisherman knot.
Thanks!
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scrapedape
Sep 11, 2006, 6:54 PM
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In reply to: In reply to: In reply to: I still had a turd flung at that post. Apparently someone disagreed. How dare you give out accurate information. :wink: I KNOW! |
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knudenoggin
Sep 11, 2006, 8:25 PM
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In reply to: Nobody that knows the answer to this, or have any pointers or comments?
be said " , i.e. loaded to be offset like the EDK"--for that knot,
incorporating a third Overhand component, was discussed here some months ago
(under "Ultimate Abseil Knot" title, IIRC).
I concur in others' opinion that the (single) Fisherman's Knot isn't good for climbing
ropes in most cases. Note that in laid (twisted) ropes, the discordant form
(upper--righthand & lefthand Overhands vs. same handedness) ensures that
one has an Overhand of each handedness, and some testing showed there to
be a strength difference between them--so you'd be sure to have the weaker
one. But I don't know of testing of the Fish.knot to check the 3 options here
(both R-handed, both L-handed, & discordant).
You can see some dismal results for it in testing of a few types of kernmantle
ropes here: http://www.caves.org/.../nh/50/knotrope.html
(Note that in all graphs, the tables' data for 10.5 & 12.5 ropes got swapped.)
As far as the Grapevine/Dbl.Fish.knot goes, images of the concordant knot (e.g.,
one posted here by cintune) show it to take a quite nice, even barrel shape,
well aligned with the line; whereas the discordant form, as show e.g. Chockstone's
Tech Tips http://www.chockstone.org/...nRopes.htm#Fisherman
takes a somewhat angled relation to the line, and by that would suffer more
abrasion (the small image is concordant, in contrast to the large one).
In reply to: Pull tests by the AMGA show that there is no strength difference ...
loopknots (of some, unknown dressing & loading!) to be of equal strength;
most sources show the former to be stronger. But in the question of use qua
Abseil-Rope Joint, ample strength is present in any knot.
*kN*
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punjabi
Nov 7, 2006, 4:12 AM
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This is somewhat of an old forum so it may be pointless to reply, but at the bare minimum it needs to be a Double Fisherman's(as shown above), not a single Fisherman's (as shown in the original post at top). Some people aren't even comfortable with a double and prefer a triple or quad Fisherman's when connecting two ropes.
-Ian
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skinner
Nov 15, 2006, 7:19 PM
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Well.. maybe the turd flinger ties his/hers like that and beleives it's a double (ya know 2 knots) in which case it's just a matter of time before they will fling no more turds!
Can't you see who the turd flingers are now?
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marckylove
Dec 28, 2006, 6:17 AM
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The double (or single for that matter) fisherman's knot is not a good knot to rappel of off because of it's propensity to get caught in cracks. The EDK or figure-eight won't get caught in cracks nearly as frequently and they move over edges much more smoothly while the double fisherman's knot abrades the rope a whole lot more. (Wo)man up and use the EDK. 
(This post was edited by marckylove on Dec 28, 2006, 6:18 AM)
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curt
Dec 28, 2006, 4:33 PM
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marckylove wrote: The double (or single for that matter) fisherman's knot is not a good knot to rappel of off because of it's propensity to get caught in cracks. The EDK or figure-eight won't get caught in cracks nearly as frequently and they move over edges much more smoothly while the double fisherman's knot abrades the rope a whole lot more...
How odd that after pulling down many thousands of ropes over the years, I have never, ever had a double fisherman's knot get stuck in a crack.
Curt
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marckylove
Dec 28, 2006, 6:23 PM
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curt wrote: marckylove wrote: The double (or single for that matter) fisherman's knot is not a good knot to rappel of off because of it's propensity to get caught in cracks. The EDK or figure-eight won't get caught in cracks nearly as frequently and they move over edges much more smoothly while the double fisherman's knot abrades the rope a whole lot more... How odd that after pulling down many thousands of ropes over the years, I have never, ever had a double fisherman's knot get stuck in a crack. Curt
Maybe it's because you spend time posting 10,000+ posts instead of climbing. But to be honest, I highly doubt that after many years of climbing you have never, ever gotten a rope stuck. In fact, as I write that, I have to believe that if you've ever climbed anything vertical or slabby then you have definitely gotten a rope stuck. Claiming anything else is probably due to faulty memory.. or maybe something else.
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plund
Dec 28, 2006, 6:38 PM
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marckylove wrote: curt wrote: marckylove wrote: The double (or single for that matter) fisherman's knot is not a good knot to rappel of off because of it's propensity to get caught in cracks. The EDK or figure-eight won't get caught in cracks nearly as frequently and they move over edges much more smoothly while the double fisherman's knot abrades the rope a whole lot more... How odd that after pulling down many thousands of ropes over the years, I have never, ever had a double fisherman's knot get stuck in a crack. Curt Maybe it's because you spend time posting 10,000+ posts instead of climbing. But to be honest, I highly doubt that after many years of climbing you have never, ever gotten a rope stuck. In fact, as I write that, I have to believe that if you've ever climbed anything vertical or slabby then you have definitely gotten a rope stuck. Claiming anything else is probably due to faulty memory.. or maybe something else.
Stand back.........
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ocary
Dec 28, 2006, 7:13 PM
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plund wrote: marckylove wrote: curt wrote: marckylove wrote: The double (or single for that matter) fisherman's knot is not a good knot to rappel of off because of it's propensity to get caught in cracks. The EDK or figure-eight won't get caught in cracks nearly as frequently and they move over edges much more smoothly while the double fisherman's knot abrades the rope a whole lot more... How odd that after pulling down many thousands of ropes over the years, I have never, ever had a double fisherman's knot get stuck in a crack. Curt Maybe it's because you spend time posting 10,000+ posts instead of climbing. But to be honest, I highly doubt that after many years of climbing you have never, ever gotten a rope stuck. In fact, as I write that, I have to believe that if you've ever climbed anything vertical or slabby then you have definitely gotten a rope stuck. Claiming anything else is probably due to faulty memory.. or maybe something else. Stand back.........
Getting a rope stuck and getting a knot stuck are two entirely different things.
*hides behind plund*
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curt
Dec 28, 2006, 7:58 PM
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marckylove wrote: curt wrote: marckylove wrote: The double (or single for that matter) fisherman's knot is not a good knot to rappel of off because of it's propensity to get caught in cracks. The EDK or figure-eight won't get caught in cracks nearly as frequently and they move over edges much more smoothly while the double fisherman's knot abrades the rope a whole lot more... How odd that after pulling down many thousands of ropes over the years, I have never, ever had a double fisherman's knot get stuck in a crack. Curt Maybe it's because you spend time posting 10,000+ posts instead of climbing.
When you think you've done 1% of the climbing I have, you let me know.
marckylove wrote: But to be honest, I highly doubt that after many years of climbing you have never, ever gotten a rope stuck. In fact, as I write that, I have to believe that if you've ever climbed anything vertical or slabby then you have definitely gotten a rope stuck. Claiming anything else is probably due to faulty memory.. or maybe something else.
As others have pointed out, getting a rope stuck and having one stuck because of the double fisherman's knot used to join the ropes are two quite different things. Perhaps if you are getting your rap ropes stuck all the time, you just don't know what you're doing.
Curt
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skinner
Dec 28, 2006, 8:11 PM
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marckylove wrote: Maybe it's because you spend time posting 10,000+ posts instead of climbing. But to be honest, I highly doubt that after many years of climbing you have never, ever gotten a rope stuck. In fact, as I write that, I have to believe that if you've ever climbed anything vertical or slabby then you have definitely gotten a rope stuck. Claiming anything else is probably due to faulty memory.. or maybe something else.
"vertical or slabby" ? I honestly can't see how vertical or slabby terrain would cause a "knot" to get struck more so then say, less then vertical or a series of broken ledges, etc, etc..
I would love too hear your explanation on this.
And.. no, in 30+ years of pulling literally thousands (a conservative estimate) of ropes connected by double fishermen knots I have never had one stuck that I had to go dislodge. I have had to fiddle fart around and flip a knot over an edge, which I would much rather do then pull, not knowing what it's lodged on, hoping my EDK magically *rolls* over the edge abrading the shit out of it, if not further lodging it in the process.
The majority of the time now.. I am rapping on dissimilar ropes. Usually a 9.2mm and a 7mm zipline. The ONLY knot I would consider joining these with is a double and/or triple fishermens.
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ozoneclimber
Dec 28, 2006, 8:14 PM
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Question for Curt, do you even know what a rack is? Not trying to be a smart ass, but I think that there has been some miscomunication.
And Marckylove, if the person on rappel actually knew what they were doing and were paying attention there is no way that they should ever get the rope (or knots, or whatever you want to refer to) caught in the rack.
Also to the best of my knowledge, the only knot for joining to dissimilar ropes, say a 10.2 mm and a 7.2 mm, is the double/triple/quadrupple fisherman's knot.
-Bobby
(This post was edited by ozoneclimber on Dec 28, 2006, 8:21 PM)
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curt
Dec 28, 2006, 8:27 PM
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ozoneclimber wrote: Question for Curt, do you even know what a rack is? Not trying to be a smart ass, but I think that there has been some miscomunication...
Don't worry about being confused for a "smart" ass--that would be giving you far too much credit. And yes, perhaps there is some miscommunication going on here; a "rack" has absolutely nothing to do with this thread. What's with all the retards coming out of the woodwork here today, anyway?
Curt
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marckylove
Dec 29, 2006, 12:28 AM
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skinner wrote: marckylove wrote: Maybe it's because you spend time posting 10,000+ posts instead of climbing. But to be honest, I highly doubt that after many years of climbing you have never, ever gotten a rope stuck. In fact, as I write that, I have to believe that if you've ever climbed anything vertical or slabby then you have definitely gotten a rope stuck. Claiming anything else is probably due to faulty memory.. or maybe something else. "vertical or slabby" ? I honestly can't see how vertical or slabby terrain would cause a "knot" to get struck more so then say, less then vertical or a series of broken ledges, etc, etc.. I would love too hear your explanation on this. And.. no, in 30+ years of pulling literally thousands (a conservative estimate) of ropes connected by double fishermen knots I have never had one stuck that I had to go dislodge. I have had to fiddle fart around and flip a knot over an edge, which I would much rather do then pull, not knowing what it's lodged on, hoping my EDK magically *rolls* over the edge abrading the shit out of it, if not further lodging it in the process. The majority of the time now.. I am rapping on dissimilar ropes. Usually a 9.2mm and a 7mm zipline. The ONLY knot I would consider joining these with is a double and/or triple fishermens.
Well, where to start. The vertical or slabby part was meant to reference sport wankers. Obviously overhanging routes don't pose the same problems that others do.
I have been rapping on the Figure-8 for litterally 5+ years and I've never had a problem with it. The only thing you have to ensure is that you tighten the shit out of it before rapping on it.
Hope this clears up any questions about my post.
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