In defence of the European Death Knot

I’ve read and listened to a lot of misinformation and misgivings regarding the European Death Knot (EDK) in climbing circles of late. Despite the grim nomenclature, the EDK is a safe and effective rappel knot and I’ll explain why in the following article.

But first, let’s take a short look at the whys and wherefores of the much maligned EDK.

The Flat Overhand Bend AKA European Death Knot (Source: www.animatedknots.com)

What is it?
The European Death Knot is more correctly referred to as the Flat Overhand Bend. Quite simply, it is a simple overhand knot tied using two lengths of cordage. It is used as a method to connect two ropes for use in rappelling/abseiling.

What’s in a name?Perhaps most of the uneasiness attached to the EDK comes from the name itself. Although the origin seems to have been lost to the mists of time, the name was likely bestowed by American climbers when introduced to the Flat Overhand Bend by Europeans.

Like many things in climbing, the EDK is counter-intuitive – it appears to be less safe than the other variants, when the inverse is actually true. Only the European part of the name stands up to any amount of scrutiny. The EDK is in fact a bend, the name given to methods of joining two ropes together, and is not likely to result in death.

Another problem associated with the EDK is that it is often conflated with the Flat Figure 8, an ostensibly similar bend which performs very differently. This has confused reporting on instances of failures.

EDK vs Flat Figure 8
Often called a “variant EDK”, a Flat Figure 8 is by no means a Flat Overhand Bend. The method for tying them is very similar, except that instead to tying an overhand, one ties a figure 8.

The best data we have on the failure strengths of the EDK vs the Flat Figure 8 come from a series of tests performed by Thomas Moyer in 1999. His data can be found here: https://user.xmission.com/~tmoyer/testing/EDK.html. He also provides links to a few other organisations which have run similar tests.

In all fairness, Moyer’s opinion is that there are better knots than the EDK. This may be true if only strength is considered as a factor, but there are other considerations to be made which I will elaborate on later. The upshot of his research, however, is that a properly tied, dressed and pre-tensioned Flat Figure 8 fails at SIGNIFICANTLY LESS weight loads than a properly tied, dressed and pre-tensioned EDK (750 lbs vs 1400 lbs)

We’ll discuss that mode of failure in the next section.

Arguments against the EDK
The method of failure for both bends is by the “capsizing” or “rolling” of the knot. The theory goes that, under load, the knot can roll on itself until eventually rolling right off the end of the tail and separating the two strands.

The story goes that there have been deaths associated with the use of the EDK, however the evidence is anything but empirical.  Four accidents and three fatalities have been attributed to EDK failure: Zion in 2002, Grand Teton National Park in 1997, Big Cottonwood Canyon in 1995 and Seneca Rock in 1994.

However, as discussed earlier, this has occurred in large part by the incorrect labelling of the Flat Figure 8, which was the bend used during three of the four incidents. Rock and Ice published an article via their website on 23rd March 2016 about an incident in Colorado in which the Flat Figure 8 was erroneously referred to as the EDK, and yet another on 26th September regarding a death in Washington. Clearly, something is rotten in the state of Denmark…

Moyer states that the EDK is not the method of choice for tying slings for use as anchors, which seems like different conversation altogether. However, he also states that he has attended only one rescue involving a stuck rappel rope, as opposed to five which were the result of rappel knot failure.

Arguments for the EDK
There are a few reasons why the EDK is a sound choice. The main argument for the EDK is that it is low-profile and asymmetrical. What this means is that it is less likely to snag in cracks or over edges, and has a tendency to turn inward to present the flat side of the bend to the rock edge. This reduces the potential for stuck rappel ropes when compared to other alternatives.

Additionally, the EDK is easy to tie, easy to undo (under normal loads) and easy to inspect. This cannot be said with such conviction for the other variations. For use in multiple rappels, it offers a significant time saving factor.

Moyer downplays the importance of these factors, stating his record of rescues (again, one for stuck rope, five for knot failure). Perhaps it’s about horses for courses… the speed and efficiency of knot tying and avoidance of stuck ropes hardly matters on single pitch sport, but on an alpine face with an incoming storm, it could be very important indeed.

His data is the smoking gun in proving that the knot is safe to use FOR ITS INTENDED PURPOSE, which is to say for rappelling. It must be stressed that the EDK, like any other knot, must be well dressed and pre-tensioned. This significantly improves the failure rate of the knot. If tied correctly, the rope is more likely to break before the knot catastrophically fails.

Moyer suspects that the incidents in question were due to user error rather than physical failure. He goes on record to say that “millions of rappels have taken place on these knots without failures” and that he doesn’t believe that “the flat-overhand will ever fail under body weight if it is tied well.”

How to tie an EDK
With all this talk about incorrect tying, let’s talk about correct tying. For more information, see www.animatedknots.com. Here are the important points:

  • Leave sufficient tail – at least 50 cm/1.5 feet
  • Dress and pretension the EDK
  • Backup can be tied in the form of a second overhand above the initial knot. Although this increases the knot profile, but Moyer states that it maintains the asymmetry and makes the knot harder to capsize.
  • Don’t use the EDK for tying sling/webbing/cordelette anchors. Moyer suggests the Tape/Water Knot or the Double Fishermans.
  • CHECK YOUR KNOTS. Inspect your buddies. Complacency = bad juju.

What about ropes with different diameters?
Great question. There is less testing on this, but the best I could find comes from here:https://www.mountainproject.com/v/edk-destructive-testing-of-different-diameter-ropes/108401408

There is not much data in comparison to the equal strands testing, however the upshot is that, once again, the cordage generally breaks before the knot fails via rolling. Therefore, it is feasible to connect two strands of unequal diameter rope, and the limiting factor will be the tensile strength of the smaller rope. That said, it must also be stressed that  back-up knots had been used (in the form of a second overhand directly following the initial EDK) and had tightened during the testing. There is no data without these back-up knots, so it’s hard to know how they would perform without reverting to plain old guess work…

In the absence of better data the answer is: Yes, you can join ropes of varying diameters, but you should also employ a back-up overhand knot.

Alternatives to the EDK
Even though it has proven itself time and time again, if the EDK still gives you the heebie jeebies, there are stronger alternatives. The cons of these are that they are harder to tie, untie and inspect, although they do offer additional strength.

The Double Fishermans is the go-to alternative for many climbers, but can be notoriously hard to untie after being loaded and can easily be tied incorrectly.

The Flemish Bend or Figure 8 Bend (the follow through, not to be confused with the Flat Figure 8 Bend) can be used, however it MUST include stopper knots on each side. The absence of the stopper knots can allow the knot to untie itself under opposing loads. It remains relatively easy to untie but has a huge profile in comparison to the EDK.

Summary
It behooves us to check our knots. That seems like common wisdom, but it ain’t so common. The watchwords here are “well dressed” and “pre-tensioned”.

The science is all there – the EDK is safe for rappelling if performed correctly. The same could be said for everything about climbing.

Should we rename the European Death Knot? Why bother, nothing else will ever stick. Death Knot sounds pretty fucking metal, and who am I to argue with that?

Ryan Siacci, Esq.
June 2016

Thoughts? Opinions? Cries of dissent?