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Best way to tie two ropes together for rapping?
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Sep 21, 2010
am I the only one that uses a square knot? safe and easy to untie icymonsters
From ct
Joined Mar 18, 2009
14 points
Sep 21, 2010
Brian,

We should. Do I still have your info? Shingo and I keep talking about getting a weekly cocktail hour going.

On the EDK, one of the areas it fared the weakest was when wet. Still plenty strong, mind you, but I think one of the ratings tests dropped it to 490 when wet. Course that's inversion, which still should be fine with enough tail. So we're probably all going on about something that is irrelevant as long as we properly tie our knots.

The reason I ask about my follow through on the tie in was that a gym employee nixed it once, saying something like "I saw a guide in Yosemite pull this knot right open." We asked how and he had no idea so we figured our combined 50 years of experience trumped his "I work in a gym" chest puffing but I never wanted to be one of those nailed-boots-were-fine-for-me-and-my-hardman-friends-so-I-don't-need-any-lightweight-BS-advice-from-you-whippersnapper-punk old farts so all of my conventions will always be up for review.

Quite happy to have learned something here today. Now excuse me while I go kick some kids off my lawn.
steve edwards
From SLC, UT
Joined May 3, 2004
551 points
Sep 21, 2010
black nasty
thanks john,

i was just dealing with this on sunday so i could tie two cordelettes togather for a rap anchor... at least i remembered the rolling trick to loosen up the double fishermans. i will have to look into this more to satisfy my edk cordlette craving.

cor

ps: hey slim, you got any #'s on these knots??
Cor
Joined Mar 6, 2006
1,175 points
Sep 21, 2010
First summit of First Flatiron
Cor wrote:
i was wondering about a edk for a cordelette instead of a double fishermans. it could be untied real easy for a number of tasks that you may use a cordelette for. anyone have any wisdom on this?


I too would be interested in some numbers. I took a course from the BRC last spring and that is how they taught us to tie our cordalettes because it was "strong enough" and much easier and faster to untie if you need to. I tie the EDK with another one cinched up behind it as a back up and have been happy (and alive) so far.

steve edwards wrote:
On that note, since some of you are pretty into this, what about following your tail back through your fig 8 tie in knot? My understanding has always been that this both increases the size (strength) of the knot as well as making it easier to untie. Any revelations in the last 20 years?


I used to back up my fig 8 tie in this way. I'd heard it called the "yosemite back-up". In the course mentioned above, our guide said that it is possible to cause that to roll and capsize as well. I'm not sure I understand it though. He said mainly if you were to clip into the loop you tied into with an "alpine style" harness with no belay loop (which applies similar forces as tying 2 rap ropes together with the fig 8 EDK) and then there is no tail for it to roll up to, since it's tucked back in. Anyway, *his* verdict is a fig 8 without a back up is stronger and safer than a fig 8 with the tail tucked back in.

Again, if anybody has any hard evidence I'd love to hear it!
Derek W
Joined Jun 27, 2008
38 points
Sep 21, 2010
For two different diameters, I've used a double sheet bend ... and didn't die.

cruising.sailingcourse.com/ima...

Have seen it taught in self rescue climbing courses, and its a standard knot in sailing.

Pretty simple to tie and evaluate; relatively low bulk.

Edit: Meant to add: Welcome feedback, and haven't seen strength test data for this knot.
Jeff Fiedler
Joined Oct 21, 2006
4 points
Sep 21, 2010
Climbing in Smuggler's Notch
steve edwards wrote:
Do I still have your info? Shingo and I keep talking about getting a weekly cocktail hour going. On the EDK, one of the areas it fared the weakest was when wet.


Maybe? Pop me an email and/or I'll do the same. Got a new point-and-shoot, need to climb with it to see how it works... Cocktail hour would be great.

Speaking of wet EDK's, a few years back, I did some tests at home. Summary below.

-Brian in SLC

"Rappel with overhand knot ala "EDK": home testing...."

Thought this might be kind of interesting...

Rappel knots, for tying two ropes together, seems to be a constant debate in some climbing circles. There's some test data out there and some vague testimonial on overhand knots collapsing (rolling) under load, or coming unraveled. A bit disconcerting for those of us who use an "EDK" ("euro death knot") or in-line overhand (aka, flat overhand, abnormal overhand, etc) for rappelling.

So, thought I'd reassure myself that everything is o.k.

Grabbed two ropes. Yellow rope is an 8.5mm Beal circa 1985 (long since retired). Red rope is a 7.8mm Bluewater Ice Floss circa 1994 (also retired).

Thread red rope through a rapide which was hanging loosely whilst clipped to a carabiner hanging off my Metolius Simulator hang board (firmly mounted to the stairwell wall, thank goodness). Matched end of yellow rope to red and tied an overhand knot, thereby simulating how I'd do it when "in the field".

Left short tails and a loose knot each time. Donned harness, clipped rappel device (Wild Country Variable Controller was handy on the gym harness) to belay loop, and carefully, so as to not tighten or load the knot connecting the two rope, positioned both rope strands to be in effect, "on rappel". Took out as much slack but was very careful that there was no complete straightening of either rope strand and no tightening of the knot. Then, slight bunny hop up (credit card check!), cut my feet out, keep brake hand tight, and come down hard onto the rappel device with the full force of my 100 kilo body weight. Did this multiple times, but, took photos of three different situations. First: rope dry. Second: rope wet. Third: rope frozen.

Lets see the results.

Test #1: Dry Ropes

EDK dry and loose pre loading
EDK dry and loose pre loading


In the photo above, you can see the tails are way too short for comfort, and the knot is very very loose. Quite poorly tied. I'd never rappel on this in the field, ever. But, since the only penalty points would be a bruised tailbone, I loaded this baby up.

EDK dry loaded
EDK dry loaded


Knot snugged up. Knot did not collapse and/or roll. The tails didn't lose much length. So, no problems noted.

Test #2: Wet Ropes

Second test, ropes left soaking in the sink (and lightly massaged) until saturated. Removed ropes from sink, dripping wet, repeat the above test.

EDK wet and loose pre loading
EDK wet and loose pre loading


Note the loose knot (can see through the middle of the bottom of the knot). Tails still too short for comfort. Rope ends dripping on floor, time to load this puppy up.

EDK wet after loading
EDK wet after loading


Pretty good spray of water as the knot cinched down hard. No noticeable slippage, no capsizing and/or rolling. Just rapid tightening as per test #1.

Test #3: Frozen Ropes

Ok, finale time. Ropes put back in sink and allowed to soak up more water. Then, into the freezer, in a plastic bag. Several hours pass, then out of the freezer. Big mass of frozen glop. Had to physically tear the frozen ropes apart, but quickly as I wanted to limit the thawing. Threaded the frozen red rope through the rapid, quickly tie a loose overhand knot.

EDK frozen pre loading
EDK frozen pre loading


Can still see air through the knot above. Ice visible on parts of the rope. No time to waste, I go on rappel and jump on it.

EDK frozen post loading
EDK frozen post loading


And...ditto the above. Knot cinched down, no rolling and/or capsizing.

These results made me pretty happy. I use a single EDK quite often to tie two ropes together for rappelling. Its easy to tie, easy to inspect, low profile, easy to untie after the rappel. I cinch the knot down pretty tight and leave 18" tails. KISS works for me. The EDK aka in-line overhand knot makes some folks nervous. And...that's o.k. Use whatever you feel is best for you.

YMMV....

Brian in SLC
Joined Oct 6, 2003
11,031 points
Sep 21, 2010
Toby B wrote:
What makes the EDK easier to pull than a double fisherman's? Seems like both would be equally prone to getting stuck in constrictions etc.


Tony the EDK can roll over edges, yes it can still get stuck, but less likely then a double fishermans
JPVallone
Joined Aug 25, 2004
199 points
Sep 21, 2010
Top of Jah-Man Sister Superior
When doing ropes of different diameters I use a doubled Sheet-bend or a EDK doubled. The sheet bend is made especially for joining ropes of different diameters together and works really well. You can back up the ends with double fisherman knots that don't cinch down on themselves. Sunny-D
From SLC, Utah
Joined Aug 2, 2006
460 points
Sep 21, 2010
Brian,

Nice demo. Pretty much sold on the EDK now for anything in the backcountry (not rigging or controlled situations but I'm sure it's fine there, too, as long as you're hauling people and not a truck or something). I figured this might be the case. I've never had a knot slip at all (using flat fig 8 or EDK) and I've ab'd off under all sorts of duress in crap situations. Maybe I've been lucky but the more I read the more I believe knot failures are user error.

Cocktail party may be in order later this week. Perhaps a bit o'craggin' too.
steve edwards
From SLC, UT
Joined May 3, 2004
551 points
Sep 22, 2010
Another Anthony (me) on Unnamed BP #2.
icymonsters wrote:
am I the only one that uses a square knot? safe and easy to untie


I'm going to assume that you're just trolling and not serious.
Anthony Baraff
From Paris, France
Joined Oct 29, 2008
2,431 points
Sep 22, 2010
The one you trust should be the one used. I like the square knot with fisherman on the ends as backup. Super easy to untie. I would NEVER use just a square knot. will smith
From boulder
Joined Jan 16, 2008
41 points
Sep 22, 2010
Rrrrr
Jeff Fiedler wrote:
For two different diameters, I've used a double sheet bend ... and didn't die. cruising.sailingcourse.com/ima... Have seen it taught in self rescue climbing courses, and its a standard knot in sailing. Pretty simple to tie and evaluate; relatively low bulk. Edit: Meant to add: Welcome feedback, and haven't seen strength test data for this knot.


If I were looking at only strength & ease to untie after loading, this is the best knot. It's the knot of choice for our rescue loads; possibly 600kg static. It's not a low bulk knot, that thing catches all kinds of rock.

We're not looking at getting the most strength that we possibly can here, we don't need it. We're moving fast and rapping with maybe 75-90kg static (ballpark average); double that if assisting a buddy. The flat overhand serves this purpose as the most effective & efficient knot along with a viable safety factor; even with that 10/8 diameter difference, it's fine.
Buff Johnson
Joined Dec 19, 2005
1,499 points
Sep 22, 2010
willie
Anthony Baraff wrote:
I'm going to assume that you're just trolling and not serious.


I have rapped off of the square knot, albeit unhappily. Had a partner who really liked, and could not be convinced to use anything else. I did back it up with fishermans however. Not entirely sure I wouldnt fight for a different knot now though.
Sisyphus
From Amherst, MA
Joined Dec 31, 2009
71 points
Sep 22, 2010
At the matching crux
Cor wrote:
on another note... what is the stregnth of the edk, and the stregnth of a double fishermans? i was wondering about a edk for a cordelette instead of a double fishermans. it could be untied real easy for a number of tasks that you may use a cordelette for. anyone have any wisdom on this?


Why tie any knot at all in your cordelette? Just leave the untied ends of the cord hanging down at your masterpoint. You will still have a MP of 2 loops which is fully redundant, and you don't have the added bulk of a knot on your harness.

John Long's equallette only has a 2 strand MP so I'm not concerned about losing a strand.

I started doing this a while back and have no regrets at all. It's double useful when using 5.5mm spectra - no triple fisherman to really bulk things up.
Jon H
From Boulder
Joined Nov 24, 2009
98 points
May 27, 2015
JPVallone wrote:
Tony the EDK can roll over edges, yes it can still get stuck, but less likely then a double fishermans


Because lots of people use something doesn't mean it's the most reliable option. (I've yet to see a Honda Civic with 200 000Km on the counter ;) )

The "only EDK avoid getting stuck" is not true. The EDK is not the only asymetrical knots out there:



For example this one above^^: the double fisherman in a flat setup (aka DT-FK).
Look at this page (have it translated from German to English): gudelius.de/spst.htm

"DT-FK kept his form and made it to a load of between 2100 and 2800 daN"(that's decanewton, or approximately 10 newton)

the DT-FK appear to be approximately 15% stronger than an EDK.

Plus, if you do a tripple instead of a double (which really doesn't take a lot more rope, time or complexity), if you miss-tie it, it will (most likely, depending on your mistake) fall back into a double fisherman anyways. Miss tying an EDK is way scarier IMO... (especially for whoever brought up the "I'm tired and I just bomb an EDK". Being tired = more prone to errors)

Yes the double(or tripple) fisherman knot, wether the conventional setup of the flat knot setup) takes a longer to do than an EDK, but it seem to be more mistake-proof and better with rope of a different diameter (In my case my new rope is a 9.5, and my old ropes are 10.2+... I don't feel safe with an EDK as strand tend to want to roll over each other given the difference in diameter)


Even very loose, the Double fisherman in flat knot setup will constrict in a way that makes the loop go smaller, not allowing the room for the "top" fisherman knot to go throught. And that remain true even if the rope from the bottom knot is completely removed from the top knot.


I can't find a lot of documentation on that knot, but from what it can see with my very unqualified opinion, if seem to be a knot that is:
+ 15% stronger than EDK
+ that allow room for error, especially if you take the habbit of doing a tripple fisherman.
+ Does not roll if loose of under high loads.
+ Is just as asymetrical as the EDK.
- But takes longer to execute. ( But most people --ie.: sport climber-- can afford an extra 45 second )



Anyone can comment on the downside of the double fisherman in flat setup ? Thanks !
Fmaz
Joined May 27, 2015
0 points
May 27, 2015
Brian in SLC wrote:
Knot cinched down, no rolling and/or capsizing.


Have you tried your tests with crossing strands ?
In some case it seem if there's a strand crossing and you're not pulling all 4 strands properly, the knot can roll up to twice under 400lbs:

See some testing made by Tom Moyer; Test 11, 14, 16 ... and they are all same diameter rope. (I imagine thoses 'mistakes' tests with different diameter wouldn't be any better)
user.xmission.com/~tmoyer/test...

I think as far as the "wet ropes" thing, it's just the same as lubing your rope: it reduce friction between the strands inside the knot. Having a different diameter also makes it easier for the strand to move into a different configuration, which in turn may or may not weaken the knot (depending on the resulting knot).

Ps.: Sorry for re-activating an old thread ! ;) ... I just have problem with the very basic mentality of seeing people saying to leave almost 2' of extra rope as "it's a knot that is likely to roll". Makes me shivers: put a stop knot instead: if it rolled once, it could roll twice !
Fmaz
Joined May 27, 2015
0 points
May 27, 2015
DWS at the Unemployment Wall, Ha Long Bay, Vietnam...
Fmaz wrote:
Because lots of people use something doesn't mean it's the most reliable option. (I've yet to see a Honda Civic with 200 000Km on the counter ;) ) The "only EDK avoid getting stuck" is not true. The EDK is not the only asymetrical knots out there: For example this one above^^: the double fisherman in a flat setup (aka DT-FK).


I've been using the EDK for a long time, but once I became aware of this flavor of the double fisherman I made the switch. It has the benefit of the EDK (rolls easily over an edge) without the sketchiness of the knot rolling/capsizing. Best of both worlds! It is harder to untie compare to the EDK, but ideally the only time you need to untie it is when you're done rapping and safely back on the ground.
aikibujin
From Castle Rock, CO
Joined Oct 14, 2014
110 points
May 28, 2015
At the BRC
Fmaz wrote:
Because lots of people use something doesn't mean it's the most reliable option. (I've yet to see a Honda Civic with 200 000Km on the counter ;)


I drive a Civic with 260,000 km on the odometer right now and sold my prior Civic still runnning after 420,000 KM. Not that unusual.

Did I miss all the reports of rappeling deaths from EDKs?
Mark E Dixon
From Sprezzatura, Someday
Joined Nov 29, 2007
200 points
May 28, 2015
Mark E Dixon wrote:
I drive a Civic with 260,000 km on the odometer right now and sold my prior Civic still runnning after 420,000 KM. Not that unusual. Did I miss all the reports of rappeling deaths from EDKs?

Darn; everytime I try to do a car analogy, it turn againt me, haha !

My point is simply:
Good is great, but better is better.


If you are to learn a new technique, just learn the best one. Doesn't mean other techniques are bad per say.


To answer your question, there's at least the incident with Karen Turk, not a death report, but close call:
"When Turk was approximately 30 feet above the ledge, Dagher states that she watched the knot “unravel,” causing Turk to fall. Turk fell about 15 to 20 feet, struck her back against a rock prow, then fell another ten to 15 feet onto the ledge, landing on her back.

Goewert said that Turk never lost consciousness, but was in significant pain. In conducting a physical assessment of Turk, he found a large laceration across her lower back, with exposed spine, but no other significant injuries.
[...]

Goewert, an experienced lead climber, said that he’s been using the overhand knot for a couple of years, but has always been a little uncomfortable with it. He added that it’s a knot used by a lot of climbers he knows. He’s not sure why the knot came untied. It had held multiple rappels and, after having been loosened, had been re-secured by himself and rappelled on once again. Goewert added that he would no longer use this knot.

[...]
She(Turk) could offer no additional information surrounding the nature of the accident, but added that Dagher had made a comment about the knot, to the effect that “it looked pretty weird” and she wasn’t clear how it could hold. This comment was made at the last rappel station. Turk said she was aware that Goewert had adjusted the knot at this station but did not see him do so.
"
Fmaz
Joined May 27, 2015
0 points
May 28, 2015
Flat overhand w/ a backup. Easy to tie, easy to check and easy to untie after weighting.... There is a great tutorial on how to tie it on a blog I follow:

seekingexposure.com/flat-overh...
CCase
Joined Feb 19, 2014
32 points
May 28, 2015
Bouldering at the top of the WG ridge: always be c...
What are people's thoughts on the zeppelin bend? I have a friend that swears by it.

Eli Buzzell
From Rumney
Joined Nov 21, 2010
428 points
May 28, 2015
The traverse out to the Yellow Ridge on the Dogsti...
Not mentioned by Fmaz:

The knot in question in this 1998 accident was loosened or partially undone and redone and then retightened/redone before the accident.

One of the climbers reported that the knot looked "weird" after it had been readjusted and before it failed.

The full accident report is at publications.americanalpineclu... .
rgold
From Poughkeepsie, NY
Joined Feb 15, 2008
308 points
May 28, 2015
i just do a square knot. Havent died yet! Collin Farley
Joined Apr 8, 2015
0 points
May 28, 2015
The flat double fishermans also has a well known failure mode in that it can separate on the pull. If the black rope's knot in fmaz's photo gets caught on something, it can pull off the end of the red rope when you start yarding on the thing. There is some info on this issue online...I believe the solution is to use a 'triple overhand' or back it up in some way. But then you end up with a pretty massive, non-intuitive thing. You can see the triple overhand here: gudelius.de/spst.htm Xam
From Boulder, Co
Joined Dec 6, 2011
8 points
May 28, 2015
I always use a simple overhand (EDK) with long tails (18") and hand tighten each of the four strands.
Heres why:
- Quick and easy to tie.
- Fool-proof to inspect.
- Doesn't get caught nearly as easily as other bulky, overkill knots.
- Plenty strong.

I used to go with a double fishermans or figure 8 followthrough but noticed that it would get caught all the time... on the tiniest of things. And as you know, the feeling of having a rope get stuck when you are several pitches off the deck is a special kind of terrifying!

Remember, the force on the knot when you are rappelling is only about half of your body weight (unless you are bounding and bouncing on rappel like a Marine). Bulkier knots are just overkill with regards to force that they receive.

P.S.- ALWAYS TIE STOPPER KNOTS ON THE END OF EACH STRAND BEFORE RAPPELLING! * Rappelling off the end of the rope is how seasoned expert climbers typically die.

Bob Dobalina
Joined Jun 2, 2009
178 points


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