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bobruef
Jul 25, 2007, 4:24 PM
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My apologies if this has been posted already, but a search didn't turn up anything.
I was waiting for some friends at the local climbing gym last night, when I picked up an issue of Rock and Ice. Thumbing through it, a couple of articles caught my eye. First was a very informative article on the effects of different battery acid on rope strength. The second was an article discussing the various merits of different methods of joining together ropes for rappel. The article discussed three different knots: The Ring bend, the double fisherman's, and the EDK. Long story short, the article called the argument that the EDK is less likely to get stuck completely bogus, and purported that it's name was aptly given. They gave it one star, and hailed the other two knots as vastly superior.
I then took a deep breath, put the magazine down, and felt good about my lack of subscription to that particular rag.
Alpinist anyone?
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socalclimber
Jul 25, 2007, 4:34 PM
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Agreed. Considering R & I deserves -3 stars for their lack of editorial content, it is difficult to take anything they say with more than a grain of salt.
(This post was edited by socalclimber on Jul 25, 2007, 4:36 PM)
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saxfiend
Jul 25, 2007, 4:37 PM
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Yeah, I saw that issue and remember thinking, do any of these guys actually climb? Only reason I get the mag is that the subscription was free, and I won't be renewing.
JL
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dingus
Jul 25, 2007, 4:53 PM
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Did they offer any support for these claims?
DMT
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bobruef
Jul 25, 2007, 4:57 PM
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I wish I had the article in front of me, so i could quote it. It was pretty bad. Just a short blurb though. Really no support for the claims, just one uninformed turd, offering up his uninformed opinion as the final word on the matter.
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moose_droppings
Jul 25, 2007, 6:09 PM
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Sometimes to some people the stigmatism outweighs the data.
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swaghole
Jul 25, 2007, 6:18 PM
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Yea, I read that article. They didn't provide much explanation, apart from the fact that the knot can roll if not properly dressed, and that with short tails, you can be in trouble. They mention one incident where someone died because the knot rolled on short tails. I use the EDK all the time if I think that my ropes can get stuck. I always dress the knot tight in all directions and leave over 2 feet of tail. Even after reading the article, it won't change how i use the knot.
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fitzontherocks
Jul 25, 2007, 6:26 PM
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Here's a good link on the EDK: ttp://www.xmission.com/~tmoyer/testing/EDK.html
The only guide I've ever climbed with used the EDK. In the article above, the author says Chris Harmston of Black Diamond uses it, and his opinion is usually well respected.
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knudenoggin
Jul 25, 2007, 6:43 PM
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bobruef wrote: First was a very informative article on the effects of different battery acid on rope strength. 
In reply to: The second was an article discussing the various merits of different methods of joining together ropes for rappel. The article discussed three different knots: The Ring bend, the double fisherman's, and the EDK. Long story short, the article called the argument that the EDK is less likely to get stuck completely bogus, and purported that it's name was aptly given. They gave it one star, and hailed the other two knots as vastly superior. I then took a deep breath, put the magazine down, and felt good about my lack of subscription to that particular rag.
Knots" is presented (in the near margins of rear pp. and odd page sequencing!).
I don't recall the acid-on-ropes one, so will re-look; but perhaps they've
repeated the knots article in another issue? Also, as noted by the title, it
concerned more than rope-joining knots--begins with tie-in loopknots, with
the Bowline & Fig.8 discussed. So, was yours a different article from that?
(This is the R&I of Duane Raleigh, of Knots & Ropes for Climbers, but no longer
that of Clyde Soles, of Outdoor Knots, eh!? Although K&RC does include it,
with some recommendation for rap-rope joining. "6inch tails" is one
point many here will want to lengthen--Clyde, e.g., doubles it.)
In another forum, I wrote:
In reply to: Rock & Ice's annual issue with its "Definitive guide to knots" is sadly laughable. They have no knot expressly targeted to tape (though they have some that can be so used--they don't say). They warn that one must be careful to tie the Grapevine correctly, but show an incorrectly tied knot (its Strangle knot components are mirror images; they should be identically oriented (same "handedness")). They dismiss the Offset Overhand Bend as unnecessary, and as the cause of a death. In fact, it was the Offset Fig.8 bend that led to (or, as best one can deduce, is believed to have ...) the tragic fall of one British climber in Zion park (and that, I hear, is as much the fault of "cable"-like ropes). To the issue of tying diff.diameter (or some other difference in nature--of slickness, flexibility, or elasticity) ropes with an Offset Overhand bend, as DMan suggests, the asymmetry of the knot can be used to advantage: one should orient the ropes such that the more flexible, less elastic one is what makes the initial choke of the mainlines where they enter; the less elastic will better resist being pried open; the thinner will better resist being pried out around its twin. One can tie the end of this first-choking rope around the opposite end with an Overhand stopper (using a full 2nd OOB/edk as rec'd by NeedleSports is overkill--missing the point--, gratuitously bulky). Or one can make one further wrap (one full turn) with this 1st-choking end before tucking it out beside its twin--which will quite surely resist being pried open. (This makes the knot formed by this rope a Fig.9.)
In this forum (and maybe rec.climbing previously), there have been pseudo-polls
about the frequency of stuck-knots (and the likelihood that, of those stuck, some
different knot would've mattered): my sense is that a fair number of climbers
reported no such issues, over even decades of climbing. Moyer, also, echoes
this doubt about the presence of the problem. But the NEClimbs forum had
IIRC a couple reporting troubles. --an issue more likely in lower-angle and
particular types of rock than others.
*kN*
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cedk
Jan 10, 2008, 8:48 AM
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Late post.
Didn't the article state that the EDK had rolled and killed a climber in Zion? If that's the accident I'm thinking of they got the knot wrong. Happened about 5 or 6 years back and it wasn't an EDK it was a figure 8 tied like an EDK; that is both long ends were on one side of the knot and both short ends on the other. IIRC some research done at the time showed that configuration was WAY more likely to roll than the EDK. Maybe it's harder to dress or something.
The article also made no mention of a figure 8 retraced in the opposite configuration (one long one short on each side of the knot). Does anyone have any oppinion of that? It's bulky but quicker to easily tie than a fishermans. I'd never used it but was of the oppinion that it was safe.
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saxfiend
Jan 10, 2008, 2:03 PM
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cedk wrote: The article also made no mention of a figure 8 retraced in the opposite configuration (one long one short on each side of the knot). Does anyone have any oppinion of that? It's bulky but quicker to easily tie than a fishermans. I'd never used it but was of the oppinion that it was safe.
JL
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dingus
Jan 10, 2008, 2:23 PM
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I've never snagged an edk. HAVE snagged a doub fisherman many times and had to reclimb or batman up to free them more than thrice.
DMT
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camhead
Jan 10, 2008, 2:36 PM
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ugis is not the first time I have heard of R&I dissing the EDK.
I really wish that they would take the responsibility of backing up and explaining all their assertions more thoroughly. Magazines are supposed to be authorities and definers; and this is just the propagation of more nonsense.
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rgold
Jan 10, 2008, 3:04 PM
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The quality of Rock and Ice's advice on safety matters is very variable. I consider it as (un)reliable as a random opinion expressed on this and other message boards---the advice may be reasonable or it may be bunk.
The EDK rating was not one of their better moments. The EDK has been extensive studied and is known to be safe when properly tied and dressed. Among the many things Rock and Ice seems not to know is that the pull-down properties of knots have been systematically studied here, and the double fisherman's knot proved so poor in hanging up compared to the EDK that they stopped testing it after the initial evaluations:
Results from actual and simulated cliff edges Sheet E-1 indicated that the Double Fisherman’s Knot did get caught on all hard edges especially
the reverse edge. (Figure 12 depicts a reverse edge). This is due to the cylindrical shape of the knot where the knot jams against the hard edges. This knot required significantly more force (nearly 40kg) than the other knots to move over a 90 degree reverse edge...Based on this evidence, further rope pull down tests on the Double Fisherman’s Knot were discontinued
The final conclusion about joining knots for rappelling, with some interesting additions unknown to most climbers, is
The Overhand Knot appears to be the best knot to join two canyon ropes together when considering cliff friction issues. However canyoners should ensure knot tails are leading towards the edge and do not drop down on reverse edges as this increases the load required to pull the knot over the edge. When setting up a canyon abseil rope ensure the Overhand Knot never engages the anchor sling or link, otherwise it will take greater load to start pulling. If the ropes are wet, the rope pull down load can be doubled. The Double Fisherman’s Knot has traditionally been the knot used to join two ropes. Whilst the strength of this knot can not be questioned, its performance in rope pull down tests was poor and for that reason this knot is not recommend for joining ropes in canyoning where rope jam could be an issue.
By the way, the inline retraced figure-8 was also tested and found to be inferior for pulling, although it did perform better than the fisherman's knot.
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tuna
Jan 10, 2008, 3:19 PM
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I might have been sleeping for a bit too long but seems to me that I have been using this knot for about 17 years.
I call it an overhand.
Long tails and if you are paraniod then tie two overhands nice and tight and close to each other.
As far as R&I who cares what they write. As long as the pictures are pretty it is just as good as Climbing.
ciao
Santana
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reg
Jan 10, 2008, 4:26 PM
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as we know - edk's will roll as stated - so will an eight tied that way (that isn't "re-traced"). and i believe i heard it'll roll easier then the edk.
anyway i wonder about the high marks for "less likely to get stuck" concept. ie: we know why the edk is given that disignation - it'll "stand up" (tails up) when being pulled over the edge and/or along rock surfaces but when it hits free air, i would think rope twist and/or gravity would/could roll the knot to face the rock exposing it to jamming. i use it and feel it's safe and less likely to jam but winder if i'm giving to much credit. also does the eight tied in the edk config stand up? - R
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saxfiend
Jan 10, 2008, 4:39 PM
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rgold wrote: By the way, the inline retraced figure-8 was also tested and found to be inferior for pulling, although it did perform better than the fisherman's knot.
JL
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markc
Jan 10, 2008, 5:32 PM
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reg wrote: also does the eight tied in the edk config stand up? - R
Do you mean an eight with the short strands exiting the same side of the knot? I don't know what to call that, so I'm having trouble searching for specific test data. However, I recall it rolling more easily than the EKD, and that it consumed more rope with each roll. I don't know if it stands up, but from all the data I've seen (and can't find), it's not a good choice for rappelling. Can anyone verify?
Update: I found some data at tradgirl:
http://tradgirl.com/.../advanced.htm#rappel
(This post was edited by markc on Jan 10, 2008, 5:40 PM)
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jt512
Jan 10, 2008, 6:07 PM
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dingus wrote: ...more than thrice.
Quadrice?
Jay
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Tree_wrangler
Jan 10, 2008, 6:11 PM
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I remember reading the results of some EDK roll tests that were posted on this site....probably within the last year. This was not long after the EDK had received much press in at least 2, if not more, accidents. In one accident (perhaps the Zion event that folks are referring too), the joined ropes had the knot come apart. Preliminary reports were that the knot was EDK, but perhaps not. Anyhow.
The upshot of the tests (multiple trials) were that the EDK was totally unpredictable in the amount of rolling that occurred. In one trial, it rolled twice before it seized hard. In another trial it rolled like 5 times, coming very close to the end of their tails (which were reasonably long, but probably 8" or less).
The conclusion of the testers upon completion, was that the EDK was unpredictable enough to be discarded as a regularly used knot.
I'll look around for that post where the test results were displayed. In any case, my memory serves accurately (for my person), so I don't need to re-read it to for myself. If anyone else has it, you might post it here for others to review.
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jt512
Jan 10, 2008, 6:13 PM
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Tree_wrangler wrote: I remember reading the results of some EDK roll tests that were posted on this site....probably within the last year. This was not long after the EDK had received much press in at least 2, if not more, accidents. In one accident (perhaps the Zion event that folks are referring too), the joined ropes had the knot come apart. Preliminary reports were that the knot was EDK, but perhaps not. Anyhow. The upshot of the tests (multiple trials) were that the EDK was totally unpredictable in the amount of rolling that occurred. In one trial, it rolled twice before it seized hard. In another trial it rolled like 5 times, coming very close to the end of their tails (which were reasonably long, but probably 8" or less). The conclusion of the testers upon completion, was that the EDK was unpredictable enough to be discarded as a regularly used knot. I'll look around for that post where the test results were displayed. In any case, my memory serves accurately (for my person), so I don't need to re-read it to for myself. If anyone else has it, you might post it here for others to review.
Looks like inaccurate information will allow the EDK "controversy" remain alive.
Jay
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Tree_wrangler
Jan 10, 2008, 6:19 PM
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Well, I didn't post anything inaccurate, so what's your point, unless you're of the belief that your opinions have more validity than real-world data?
http://groups.google.ch/...=de#48714bff63f90862
One documented case of an EDK failure. Sounds like they monkeyed with it a little bit. Nothing conclusive.
(This post was edited by Tree_wrangler on Jan 10, 2008, 6:38 PM)
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boku
Jan 10, 2008, 6:23 PM
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Tree_wrangler wrote: ...coming very close to the end of their tails (which were reasonably long, but probably 8" or less)...
I believe that 8" tails is unreasonably short for an EDK in ~ 10mm rope. I'd use 18" tails, and accept no less than 12".
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jt512
Jan 10, 2008, 6:27 PM
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Tree_wrangler wrote: Well, I didn't post anything inaccurate, so what's your point, unless you're of the belief that your opinions have more validity than real-world data? http://groups.google.ch/...=de#48714bff63f90862 One documented case of an EDK failure. Sounds like they monkeyed with it a little bit. Nothing conclusive.
That link doesn't work.
My point is that there have been tests of the EDK that showed the exact opposite of what you have claimed about it. I'd be interested to see what data you are referring to, but I don't see how it can be valid, given the well-known test results that I and others have seen.
Jay
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Tree_wrangler
Jan 10, 2008, 6:32 PM
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In reply to: I believe that 8" tails is unreasonably short for an EDK in ~ 10mm rope. I'd use 18" tails, and accept no less than 12".
Sounds fine.....I'm not for or against the knot (disclaimer)
Here's the test I remembered.
http://www.xmission.com/...yer/testing/EDK.html
Quick summary (I didn't carefully pore through it)
EDK w/ dry ropes....knot held, ropes broke at a wide spread of pulls, during multiple tests. Anywhere from 1400-2100 lbs.
EDK w/ wet ropes....knot rolls indefinitely and comes undone.
(just for perspective)
Double Fishermans....ropes break at over 2500 lbs, even when tied improperly or ropes are wet.
I'm sure there is more out there. I'll let y'all decide for yourselves, but one thing is certain: The results are far from conclusive, and the EDK does not appear to be totally failproof. What that means in the real world is hard to say.
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