Water knot failure while Canyoneering

This article is a long time coming. I've wanted to share my near death experience to hopefully prevent it from happening to anyone else. On February 2nd of 2022, we were canyoneering near Moab Utah. I fell between 35 - 40 ft directly onto a sandstone ledge. Long story short, the crew and I self rescued which involved 2 more rappels and a 5ish mile walk to our vehicle.

My helmet and the the people with me saved my life (not to forget the hospital staff and Doctors). 2 weeks in a medically induced coma, facial reconstructive surgery, 2 broken wrists, my tibia through my ankle, and months of recovery. 

4 people rappelled on the water knot (that I tied) made of tubular webbing, with tails around 6-8 inches. Being the last person to rappel, I assumed the knot was safe and had set, but the moment I weighted the anchor it completely untied and walked out.

Unfortunately, I don't fully remember what happened before I rapelled, but I have a vague memory of shifting the webbing anchor to check the water knot's tails, then shifted it back to its original position. My theory is that the knot potentially never set due to friction on the sandstone, and/or when I adjusted the webbing back to its original position the water knot might have rolled or snagged a rock that shortened a tail or loosened the knot. 

I don't think it'll ever be solved why it walked out, but check your knots, back everything up, and wear a helmet.

Good you got to write that post!

Not much to add, but I never liked using water knots for tied slings. Always used a double fisherman's, despite the bulk.

Over the years I have always been fascinated by how knots slowly come undone by just weighting them.

x15x15 there is a whole branch of mathematics that studies knots. It's supposedly a particularly difficult aspect of math as well.

I’m curious about the details of what kind of webbing it was. When I was learning to climb many years ago, we used 1 inch “milspec” nylon webbing to make slings etc. It has a fairly soft hand and little ridges across the surface. I found water knots to be fairly reliable if tightened under body weight. I had slings that stayed tightly tied for years (I would check and re-weight regularly). 

At the time there was also “climb spec” webbing, which I think is what most climbers use by default now. It’s a denser weave with a firmer hand and smooth surface. To me, water knots seem less reliable in that webbing.

I agree with Cherokee that double fisherman seems more reliable in that webbing, although to be fair I have not rigorously tested that. I like how it seems self-tightening because the two sides jam into each other. A water knot, if loosened by tugging on one of the outer bends, seems to run through a ton of webbing before tightening again, if it does at all. The effect seems worse with smooth webbing.

Double fisherman uses up more webbing to tie, though, so might not always be an option. 

Very glad you survived! Self-rescuing down 2 more rappels and 5 miles is crazy impressive.

x15x15 wrote:

Over the years I have always been fascinated by how knots slowly come undone by just weighting them.

Cyclic loading with a water knot and the ends will creep, yes? I think so - I've seen slings left for anchors, tied with a water knot, and one or both of the ends are almost inside the knot. No one would tie the knot like that. RGold should have chimed in about this by now. 

Hunter Kessler wrote:

the water knot might have rolled 

Sorry about your accident.  The above statement confused me, a water knot can't roll to my knowledge.  Are we talking about a flat overhand?

Glad you’re still with us.

Water knots that are properly tied, dressed and set don’t untie after 4 loading cycles. My guess is something was not done correctly. 

curt86iroc wrote:

Glad you’re still with us.

Water knots that are properly tied, dressed and set don’t untie after 4 loading cycles. My guess is something was not done correctly. 

I agree. I tie all of my nylon webbing (tape) slings with water knots (aka ring bends). I tie them tightly with sufficient tails sticking out. I bounce-load as many as convenient, and I constantly monitor all that are on my gear rack, harness loops, and over my shoulders. If any loosen, I tighten them. If I’m going to rappel from in situ slings, I check all of those for condition and tighten knots when necessary. 

Obviously it's difficult to know your exact situation, but in Moab and North Wash, I commonly find water knots done with the tails in the same direction versus opposing. 

James - wrote:

I’m curious about the details of what kind of webbing it was. When I was learning to climb many years ago, we used 1 inch “milspec” nylon webbing to make slings etc. It has a fairly soft hand and little ridges across the surface. I found water knots to be fairly reliable if tightened under body weight. I had slings that stayed tightly tied for years (I would check and re-weight regularly). 

At the time there was also “climb spec” webbing, which I think is what most climbers use by default now. It’s a denser weave with a firmer hand and smooth surface. To me, water knots seem less reliable in that webbing.

This is a good distinction to make. Climb-spec webbing is much more smooth/slick than mil-spec webbing. 

Ryan Marsters wrote:

Obviously it's difficult to know your exact situation, but in Moab and North Wash, I commonly find water knots done with the tails in the same direction versus opposing. 

Wait - what do you mean by "tails in the same direction?" Do you mean that people are tying flat overhands (also called euro death knots) in webbing?

Just so we are clear… water knot:

NOT a water knot (and not a safe way to close a loop of webbing):

James - wrote:

I’m curious about the details of what kind of webbing it was. When I was learning to climb many years ago, we used 1 inch “milspec” nylon webbing to make slings etc. It has a fairly soft hand and little ridges across the surface. I found water knots to be fairly reliable if tightened under body weight. I had slings that stayed tightly tied for years (I would check and re-weight regularly). 

At the time there was also “climb spec” webbing, which I think is what most climbers use by default now. It’s a denser weave with a firmer hand and smooth surface. To me, water knots seem less reliable in that webbing.

I agree with Cherokee that double fisherman seems more reliable in that webbing, although to be fair I have not rigorously tested that. I like how it seems self-tightening because the two sides jam into each other. A water knot, if loosened by tugging on one of the outer bends, seems to run through a ton of webbing before tightening again, if it does at all. The effect seems worse with smooth webbing.

Double fisherman uses up more webbing to tie, though, so might not always be an option. 

Very glad you survived! Self-rescuing down 2 more rappels and 5 miles is crazy impressive.

It was blue water 1 inch nylon climb-spec tubular webbing (tape)

curt86iroc wrote:

Glad you’re still with us.

Water knots that are properly tied, dressed and set don’t untie after 4 loading cycles. My guess is something was not done correctly. 

That's what I also assumed too. That's what's so confounding about it. To my understanding, a water knot tied incorrectly would have failed nearly immediately. That's where the speculation of it rolling and/or snagging something came from. A friend and I did test the theory proving it possible.

Hunter Kessler wrote:

 To my understanding, a water knot tied incorrectly would have failed nearly immediately.

maybe, maybe not. it's hard to say since you can tie the knot incorrectly multiple ways. i could also see a knot tied properly but not dressed or set appropriately holding for a few cycles before letting go. really difficult to know for sure..

Glad you survived this horrible accident. One thing I don't think you mentioned is how you know it untied as opposed to cut, or melted. Did the webbing come down with you in the fall? Were there rap rings? What was the webbing attached to?

Hello Hunter,
I'm interested in trying to determine the cause of the failure mode you encountered (although I acknowledge that you experienced trauma and it may be difficult to discuss in depth).
Here are some links:

[ ] Gary Falk fatality (knotted sling failure): https://www.nps.gov/aboutus/foia/upload/GRTE_GaryFalk_Fatality_Incident-Report_NP16114877.pdf 

[ ] American Alpine Club accident report (Gary Falk): https://publications.americanalpineclub.org/articles/13201214423 

[ ] Walter Siebert video:  https://www.youtube.com/watch?v=mXe-8GmS08k&list=PLne435yhSICcA3-wGJ5Arx5furwMUUT89&index=2 

[ ] American Alpine accident report (fall from anchor): https://americanalpineclub.org/news/2024/8/13/the-prescriptionaugust 

With regard to the above sources, is there any similarity with your incident?

If yes, can you be specific?

Note:

Its the small details that matter... eg the length of 'tails' in your hand tied knot; whether the hand tied knot was tightly set; when was the last time that it was visually checked and verified; the presence of potential protrusions/snags on the rock surface the knot was pressing on; etc etc. Witness opinion/report (from the person or persons who was with you)?

You mention that the sling material was "blue water 1 inch nylon climb-spec tubular webbing (tape)".

Link: https://www.bluewaterropes.com/product/1-tubular-climb-spec-x-100-yds/ (is this the product?).

Very glad the OP survived. This post definitely makes me rethink the water knot, which I had always assumed safe as houses. Here’s a relevant post on Alpine Savvy: https://www.alpinesavvy.com/blog/rethinking-the-water-knot?format=amp 

Glad you made it OP!  Hope your bod healed up well. A few thoughts:

- yet another FFS wear-your-helmet example!

- at least it was you…I know that sounds fucked up, but you’d feel worse if someone else fell from a knot you tied.

- I’ll check a bit closer next time I tie/ rap on/ encounter a water knot. 

Wow, glad you survived.  I've been crusading against water knots in webbing for years---the tails can creep into the knot under cyclic loading and then the knot fails---this is what killed Gary Falk.  But six-inch tails and four loading cycles?  Nothing even close to that has ever been documented, and I think something else had to have been wrong.  There is a way a water knot can snag and open.  Walter Siebert does a demonstration at https://www.youtube.com/watch?v=mXe-8GmS08k&list=PLne435yhSICcA3-wGJ5Arx5furwMUUT89. He mentions a number of accidents in Europe presumed to have happened this way.  It seems pretty unlikely, but I don't think tail creep via cyclic loading could have been the cause of this accident and that leaves snagging as a possibility

Use a double fishermans.