If this topic continues to elicit responses, maybe it should be split off into a separate thread?

I sent R&I the following letter on this general subject. It may prove to be too long to be published as is.

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Real-world climbing decisions are always a matter of balancing various competing considerations. In the recent Gear and Safety guide, R&I has apparently decided against acknowledging the issues involved in favor opting for promoting rules, and has further decided to provide little or no discussion of its recommendations.

Of course, any discussion, no matter how relevant and focused, could only dilute the authority of the rules R&I chose to present. One cannot help but wonder whether the absence of a byline for these proclamations indicates the author's recognition of the nuances that have been swept under the table in pursuit of what seems to me to be an unrealistic certitude. It is certainly strange to see what one assumes to be critical observations about safety scattered incoherently throughout the issue as if their main purpose is to function as filler. Unless of course...that was their main purpose...

In some cases, R&I's commentary seems as uninformed as it is prescriptive. For example, the anonymous author of Frigging the Rigging discounts the claims that the EDK being is likely to jam as "ridiculous," arguing that when ropes do jam it isn't because of the resistance to pulling them. The only study that I know of that actually measured pulling resistance of various knots, by Peter Drohan, available as a .pdf download at http://www.bwrs.org.au/research/index.htm, came to the following conclusion:

"The Double Fisherman’s Knot has traditionally been the knot used to join two ropes. Whilst the strength of this knot cannot be questioned, its performance in rope pull down tests was poor and for that reason this knot is not recommend for joining ropes in canyoneering where rope jam could be an issue."

The same anonymous author goes on to say that the EDK's potential for "capsizing" was the cause of a fatality in Zion, but that fatality occurred with a figure-eight variant that had been known for some years to be inferior, precisely because of its greatly increased tendency to capsize.

Other recommendations seem a bit quaint. The idea, in Don't Have a Bum Rap, that a few biners will keep 60m-70m of rope from blowing around in a high wind is certainly questionable, and there is no mention of the potential risk of damage to the biners that might occur as a result of being thrown down and then bouncing around at the end of a rope. The author claims it is "almost always" possible, in mid-rappel, to free ropes stuck by virtue of knotting the ends, thereby immediately begging the question. How easy will it be, for example, if the ropes blow horizontally and jam 60m away? Meanwhile, the option to lower the first climber down, which solves the rope blowing problem as well as eliminating the danger of the first climber rappelling off the ends, is never mentioned as an option.

I think R&I would perform a more valuable service to the climbing community if, rather than promulgating rules that are destined to be ignored, it would instead air safety discussions that are attuned to the variety of choices climbers face, that expose the pros and cons of making those choices, and that own up to some of the genuine uncertainty we have to live with.

just a quick switch back to the EDK:

could anyone please give my an explanation or a source why this knot is seen so negative in the US?
EuroDeathKnot. why? Yes it is used in europe for ages, but why death? just because of the rolling issue, thats more of a non issue, if you tie it properly?

what is better:

to rappel with a rope that is joined by an "EDK", with your tails being 29cm long after five rappels, instead of the 30cm you started with, or . . .

Except the second, unnecessary knot defeats the purpose of using the first instead of a double fisherman.

Jay

http://www.xmission.com/...yer/testing/EDK.html

The writer does mention a case where an injury resulted from the "good" overhand version of the EDK.

Except the second, unnecessary knot defeats the purpose of using the first instead of a double fisherman.

Jay

uhhh, read the article more thoroughly. He never says if the accident was from a "good" version of the overhand EDK or not. He just says it was concerning the overhand EDK.

If you read the detailed ranger's report of the accident in question, you will see that the knot was dicked with– loosened and such– immediately before the accident. The knot also had reportedly "between 6 and 8 inches of tail."

Also, right before the accident, the rappelers moved the rope so that the knot was perhaps two feet below the anchors, causing the load to pull at a greater angle on the rope.

None of these factors really seem to add up to a "good" version of the EDK.

(personal note: if I am ever particularly sketched on using an EDK for whatever reason, I simply back it up with another EDK. Any over-analyzers want to debate the sage wisdom of this practice?)

Theoretically, yes, it defeats the purpose. In my practical experience, less so. I'm sure Jay will find a hole in my logic.

A doubled EDK does not 'defeat' the purpose, ie less likely to get stuck. Less likely than what???

A x2 fisherman? No.... way.
x2 EDK knots still stand up when you pull on the rope, just like a single, raising the knots away from the rock and drastically reducing friction, ergo less likely to get stuck.

DMT

...I often set a single overhand up tight against the EDK in one strand. This only increases the volume slightly, while making it impossible for the knot to roll. Best of both worlds, IMO.

I like the idea of your backup knot and might start using it as a nice compromise.

By the way I think I read somewhere that the EDK should not be used on ropes of differing diameters, like those in your photo, as the failure strength can be signifigantly lower in that case.

I often set a single overhand up tight against the EDK in one strand. This only increases the volume slightly, while making it impossible for the knot to roll. Best of both worlds, IMO.


GO

By the way I think I read somewhere that the EDK should not be used on ropes of differing diameters, like those in your photo, as the failure strength can be signifigantly lower in that case.

By the way I think I read somewhere that the EDK should not be used on ropes of differing diameters, like those in your photo, as the failure strength can be signifigantly lower in that case.

This is a cool Idea. It seems intuitive that it would not roll any more. BUT even though I'm convinced it's totally safe, I'd love to find out what the failure mode is now? Does the rope break? Is an experiement in order?