A Better EDK?
I learned a new knot [right knot in picture above] from a very reliable guy, but I can’t find any info about it. It’s a simple knot, better I think than the EDK [left knot in picture above] for joining two rap ropes. My proposed new knot:
• Does not roll like the EDK (when well dressed and with every strand tightened)
• It is easy and quick to tie (like EDK)
• It is easy to untie (slightly harder than EDK)
Since my knot seems so great, why isn’t it popular?
Another thing: Can I also use my knot or the EDK to tie slings and rig anchors?
—Jonas Sigurosson, via rockandice.com
[Feature Image: The EDK (left) is a simple overhand. The EDK variation in question (right) is the same knot, but with an extra turn through the loop. NOTE: Both knots are shown loose, and should have tails at least two feet long.]
I’d never seen that knot, so consulted the oracle, The Ashley Book of Knots. Containing approximately 3,900 knots, this was the magnum opus of seafarer, artist, sometimes sea-surgeon, and “formidable collector of pewter,” Clifford W. Ashley. If a knot has ever been tied by human hands, Ashley documented it.
On page 50, knot number 292, you find “The Gut Knot,” a knot for tying fishing leader. Ashley illustrates the knot in a tied loop, but it is the same knot as your discovery: an overhand with an extra pass through the loop.
Your knot, if it lives up to the hype, could be an improved EDK by being less likely to capsize and untie itself.
I pull tested your knot four times using a 8.9mm rope. A lot more work needs done to determine how your knot holds on ropes of dissimilar diameters, and varying slickness and density. Still, I did get enough information to know whether your knot can capsize, which you noted is its selling point. (Since your knot is for “body-weight only,” i.e. rappelling, I wasn’t concerned with breaking strengths; those tests at a later date).
In all four tests your knot did capsize, although the rope always broke inside the knot. When I left 10-inch tails, the tails were 5-inches long when the knot broke. To get an idea about whether really short tails could cause the knot to completely unroll, I left 3-inch tails. This knot also broke, with the 3-inch tail ending up being just an inch long. In theory, if you tied 2-inch tails the knot could capsize off the ends, but only a dolt would leave such a short tail in a critical knot.
That your knot did capsize isn’t surprising since it presents the same geometric shape as the EDK, and loading wants to pull the knot apart, same as it does with the EDK. Really, all your knot does is present more bends for the capsizing portion of the knot to roll over.
Bottom line: The knot might be marginally better than the EDK. I didn’t like it because it was trickier to tie without crossing the cords.
If you use the knot, leave 24-inch tails and tie an EDK back-up in these … which defeats the purpose of your knot.
To answer Part 2 of your query, about whether you can use the EDK to rig anchors and tie slings, Thomas Moyer, in his excellent online article (recommended reading), “Pull Tests of the Euro Death Knot,” says that the EDK is a “bad choice,” for tying slings. “Why would you need the pulling advantage of an asymmetrical knot [the EDK] in a tied sling?” says Moyer. “And why would you be willing to put up with the uncertainty in the strength? Tie a real knot. I use a water-knot for slings I plan to untie later, and a single or double- fisherman’s for slings I don’t plan to untie—like slings that I leave at an anchor.”
I heartily agree. Next!
This article appeared in Rock and Ice issue 237 (October 2016).
Got a question? Email firstname.lastname@example.org
Are Adjustable Leg Loops Useful?
Are adjustable leg loops actually useful? I rock climb, and ice climb some, and need a new harness. I’d rather have a less expensive and lighter harness with non-adjustable leg loops, but I’ve heard that … Continue reading “Are Adjustable Leg Loops Useful?”
If I’m on a route and my leader yells “rock!” and there’s no good cover close should I look up to try to see where it’s coming from or just hug the rock and hope … Continue reading “Rockfall Safety”