Discussion Topic |
|
This thread has been locked |
| Messages 1 - 20 of total 20 in this topic |
ulybaZZa
Trad climber
Bonn, Germany
|
|
|
Topic Author's Original Post - Sep 1, 2010 - 08:30am PT
|
I was wandering what are the cons of using butterfly knot for trying two ropes together for rappeling and making loops out of cord.
It looks like EDK (euro-death) or DFK (double fisherman) are recommended for the first and DFK for the second, but they both seem to be harder to untie. Then DFK is more complicated to tie and EDK is less secure than butterfly.
To me it seems like butterfly (used as a bend instead of more regular loop version) is a great knot for securely joining two ropes. I've never seen it recommended for rappeling or cordelette-making though. Any ideas why?
|
|
noshoesnoshirt
climber
Arkansas, I suppose
|
|
Butterfly for tying ropes together for rapping?
Hope you enjoy jugging stuck lines.
|
|
ulybaZZa
Trad climber
Bonn, Germany
|
|
|
Topic Author's Reply - Sep 1, 2010 - 10:12am PT
|
Is it really much worse than EDK and DFK for getting stuck? I've heard this before, but it's a bit hard to see why theoretically. And I guess nobody verified this in practice cause there are not so many stuck line jugging lovers around...
|
|
Holdplease2
Big Wall climber
Yosemite area
|
|
I have a question about this too and would love to hear from you guys.
Is the Butterfly Knot really a hard not, that won't slip (and eventually fail) with repeated cyclical loading, such as jumaring and hauling? I was climbing with a partner recently who suggested that this was not an appropriate knot for such activities.
I searched online and found that the knot is popular for sailors/boaters because it is easy to untie, and that it is used as a real "knot" but I just don't know.
I know its a great way to isolate a section of rope or tie a climber in to the middle of a rope, it seems like this is the most common use of it in a climbing situation. It is awfully convenient for tying ropes together that will be weighted, but is it really a good idea?
Thanks in advance
-Kate.
|
|
Roger Brown
climber
Oceano, California
|
|
This was by far my worse season for stuck ropes. Because of the nature of the Half Dome project, most of the work day was spent repositioning the ropes. The "main Line", for the most part was 1800' long. All the knots were re-tied on a regular because of stress and wearing issues. The Butterfly knot is probably my favorite knot with the fisherman's knot a close second, but I never use them for joining ropes together. The follow through figure eight is the only knot I use for joining my ropes. Bolt replacement is kinda different in the since that everything is always weighted and the direction of the loading on the gear is always changing. Any knot I use gets a pretty good workout and the follow through figure eight is the one I feel the most comfortable with. Just my opinion.
Roger
|
|
justthemaid
climber
Jim Henson's Basement
|
|
Climbers have been tying knots together for a lot of years. I suspect there is a reason this knot is not generally used to join ropes together. I'm actually having trouble picturing how you would use it to join ropes together since this is knot used to isolate a bite. I guess I'd have to see a picture.
My experienced partners use EDK/overhand to minimize problems in areas that cause stuck ropes. Learning to have the second person slide the knot clear of the edge before rapping down also helps to keep it from getting stuck when pulling it.
|
|
murcy
climber
sanfrancisco
|
|
|
|
ulybaZZa
Trad climber
Bonn, Germany
|
|
|
Topic Author's Reply - Sep 1, 2010 - 11:57am PT
|
Using it to join ropes together is easy: just imagine that the ends of your ropes are connected and tie a butterfly on the bight. Yes, I also read that EDK gets stuck much less than butterfly, it would be interesting if someone knows the explanation for this, cause I can't quite understand it. And then still there's cordalette.
|
|
Auto-X Fil
Mountain climber
|
|
The EDK is flat so it slips over edges. Tie one of each and pull them over a desk edge and see.
Use a fig-8 follow-through for cordalettes. Easy to untie, but strong and secure. I switched and haven't looked back.
Do NOT use a fig-8 on a bite for cordalettes! It can roll, much easier than the EDK.
|
|
justthemaid
climber
Jim Henson's Basement
|
|
Thanks for the picture. My brain just sees two interlocking granny knots. I couldn't comfortably use it. Ease of untying is not really something I look for when I'm hanging my life off of something.
Do not use overhand fig 8 ever for joining things. Overhand fig 8 = death. It has tested out as worst rappel knot of them all.
|
|
'Pass the Pitons' Pete
Big Wall climber
like Ontario, Canada, eh?
|
|
Very interesting, the photo above - thanks, Murcy. I personally have never joined two ropes together using a butterfly as shown above. Obviously it would require much longer tails than shown. I think it would be a tricky knot to tie if you didn't first join the ropes together with a separate knot.
The butterfly knot is a BRILLIANT knot for big wall climbing in a few applications, like attaching your pig to your haul line and putting rebelays in a rope. This is because it is so easy to untie after being weighted. In fact, I cannot think of a single instance that I would use a figure-8-on-a-bight - in every situation I would instead use a butterfly. Bluewater had a little schtick once that shows the butterfly knot is actually a bit stronger than the fig-8-on-a-bight, too - something like 70% vs. 65% knot strength.
Euro Death Knot [EDK] is far and away the best knot for joining two rappel ropes because the knot is flat and will more easily slide over edges without catching so much. It *should* be tied with two identical, or nearly identical, ropes. You also have to tie it correctly - make sure the strands don't "cross themselves" in the knot, and make sure you leave long tails. Don't join two ropes of very dissimilar diameters, they need to be pretty close. I have done it joining dynamic and static ropes of the same diameter, but caveat climbtor.
Its best application for joining two ropes together is for when you have to cross a knot while jugging a fixed rope. Obviously you would try to set up a rebelay, but where you're hanging in space, like what happens when you fix to the top of 4 on Tangerine Trip on El Cap, this is the knot to use:
What's nice about it is that you have a built-in loop to clip into when you are passing going up with jugs as shown, or down via rappel. Plus it's easy to untie when you're finished.
You can click here for the entire Tech Tip:
http://www.climbing.com/print/techtips/ttaid222/
|
|
Ghost
climber
A long way from where I started
|
|
The EDK is flat so it slips over edges.
It's not just that it's flat. It also has the tendency, when it encounters an edge, to roll so that the flat side faces the edge.
|
|
knudeNoggin
climber
Falls Church, VA
|
|
As has been noted, the "EDK" (Offset Water knot) is favored for joining abseil ropes because its offset nature enables it to move over edges & rough surfaces without snagging; it is also rather small, overall. Moreover, it's quick to tie and pretty easily untied, and in fact given its asymmetric nature even well accommodates ropes of different diameters within the usual ranges climbers will have (e.g., 7mm + 10.5mm). For joining unequal-diameter ropes, ensure that the thinner rope is that that makes the (initial) choke of the loaded parts where they enter the knot,
and here this thinner rope would have to be pulled wide enough to roll out around the thicker line for the knot to "roll" ("flype") --difficult. For added assurance, tie off the thinner rope's tail with a (single) Overhand knot around the thicker tail snug to the knot body; this will resist feeding material to the choke and preclude such rolling.
For making loops --slings/runners?--, you want good strength and aren't usually untying them.
For closing a cordelette, you need NO knot -- just bring the tails out through the powerpoint knot which makes the clip-in eye, leaving all legs of the cordelette knot-free !
In other uses, IMO the Butterfly has only the benefit of a known way of being tied and name familiarity over symmetric knots of a similar nature such as Rosendahl's "Zeppelin" bend, Ashley's Bend #1452, & --most secure when slack-- Ashley's Bend #1425, all of which are also interlocked - Overhands knots easily untied after loading.
*kN*
|
|
noshoesnoshirt
climber
Arkansas, I suppose
|
|
I use the EDK to join ropes for one because it is less apt to jam, but also because it is so simple to tie.
Often when you are on rappel you're pretty well used up from the climb and your mind is edging towards auto-pilot. I like using knots I've tied about a jillion times and know I can tie freezing, tired and brain-dead.
With that in mind, if you have the butterfly down cold, stick with it.
|
|
ulybaZZa
Trad climber
Bonn, Germany
|
|
|
Topic Author's Reply - Sep 1, 2010 - 07:04pm PT
|
Thanks to everyone for long and comprehensive answers. I think you have me convinced about the benefits of EDK for rappels. For loops, however, I still have the impression that butterfly would be good. Yes you want good strength, and butterfly is good strength, and easy untying is not necessary but it's a nice bonus. Last but not least, for me it's one of the easier and quicker knots to tie, so it seems to be a good option when you have to make that loop fast and want to be sure about it.
I will do some experiments regarding the behavior of knots when subjected to repeated loads/unloads and then we'll see.
|
|
arichy
Trad climber
quietly fighting behind the zion curtain
|
|
|
Jul 28, 2016 - 09:01am PT
|
ulybazza- have you looked at the butterfly as a bend more? I have been wondering about this too and it seems both fairly obvious and probably not such a bad idea? And you always see people doing way less obvious things that seems like terrible ideas- why no butterfly bend? I'm not sure exactly what I would use it for, probably not tying rap lines together, but as you say, maybe for cordelette, or maybe it would become obvious once I see what the pros/cons are (beyond the obvious). Anyway I might fiddle with it some but thought I'd see if any body else has messed with it much. Anybody?
|
|
Mark Force
Trad climber
Ashland, Oregon
|
|
|
Jul 28, 2016 - 11:02am PT
|
EDK for situations where there is a possible "stuckness."
Square knot with fisherman stoppers otherwise - that set-up unites like a dream.
Edit: meant to say fisherman backup knots
|
|
arichy
Trad climber
quietly fighting behind the zion curtain
|
|
|
Jul 28, 2016 - 01:00pm PT
|
I like the thinking outside the box- using a square knot to tie rap lines together. Thats one situation where I would definitely tie back up knots. And, yes, it unites like a dream.
But... I am not interested in preferred rap knots (I have plenty of my own opinions there). I am interested in the idea of using the butterfly as a bend. Pros/cons? Anyone?
|
|
Tom
Big Wall climber
San Luis Obispo CA
|
|
|
Jul 28, 2016 - 02:55pm PT
|
PTPP's photo is now gone, and so is the link he posted.
It showed a double-fisherman's knot in the bight of a butterfly knot. You tie the DFK, and then tie the butterfly knot. The DFK should be well offset to one side of the bight, not in the middle.
The two ropes are joined by the butterfly, with the DFK as a backup. The loop allows you to clip in and hang while moving your rap or jugging rig around the knot.
Here is one way to tie the butterfly knot. I have used a similar method that involves overlapping the loops on your hand, so that the middle loop is at the far right.
[Click to View YouTube Video]
|
|
Mark Force
Trad climber
Ashland, Oregon
|
|
|
Jul 28, 2016 - 09:20pm PT
|
Dang, I've been doing it wrong all these years!
|
|
| Messages 1 - 20 of total 20 in this topic |
|
SuperTopo on the Web
|
Let us know!