UKH

I've been looking to resling some 2nd-ham cams and have been looking at which knot to tie the webbing with. 

The double fishermans bend seems like a good choice - a bit more bulky than a water knot but more secure (referring to the cyclical end creep of the water knot). I've done a good bit of research and have found good sources explaining that double fishermans is fine in webbing when you don't expect to be able to untie the webbing once weighted.

I've been practicing tying the double fishermans bend with webbing but it always looks a little 'off' compared to tying it with cord or rope. Is there any tricks to making it look nice? Or is will it always look a bit weird tying the bend with flat webbing?

With no recent teaching I always thought the rethreaded thumb knot/water knot was the preferred knot for tape. I will be interested to see others comments.

FWIW I'd probably be using 5.5mm high strength cord rather than tape - as per https://www.needlesports.com/Catalogue/Climbing/Rock-Trad-Climbing/Cord-Tap... 

It is what all my old Rockcentrics have been reslung with after the original slings got destroyed Winter climbing.

Unfortunately, I can't comment explicitly on tying tape since I haven't really done it since 2006 with some cam hooks and skyhooks where for the potentially lower forces, an overhand knot was sufficient.

Old climbing texts like Fyffe & Peter recommend a water knot with long tails of five times the tapes width.

Just use a tape knot. It's what it's for.

My first thought was:

The tape knot/water knot/ring bend is subject to creeping.  I've seen it get dangerously close to untying in my own slings (when we used to tie them), and a few years ago an IFMG guide was killed in the Tetons when a tape knot used to make a tether failed. https://publications.americanalpineclub.org/articles/13201214423/Rappel-Err... .  There's a photo of the recovered untied knot in https://www.jhnewsandguide.com/news/cops_courts/knot-slip-likely-killed-fal... .

Tail creep has been measured at about 0.004 inch per load cycle, https://user.xmission.com/~tmoyer/testing/Water_Knot_Testing.pdf , but I suspect the creep gets smaller as the knot tightens. If not, then 250 load cycles could possibly creep in a 1" tail, and something like this is probably what happened with the guide.  If you make the tails long enough (3"), bounce tighten the knot, and mainly are careful to inspect, it should be ok and obviously has worked for a very large number of users.

A second problem can occur if the knot hangs up on something, as illustrated in the following video, in which it is claimed that there have been at least 20 deaths in Europe because of this.  youtube.com/watch?v=mXe-8GmS08k& .  The proposed joining solution, unfortunately, is not useful, and the double fisherman's is never mentioned.

The amount of loading over time required to creep a water knot open probably means most climbers won't have trouble with their slings and slung gear, as long as they pay attention to the status of the ends.  A much more dangerous situation occurs when webbing tied with a water knot is left in-situ for rappelling, because then a very large number of loading cycles is no longer unlikely.

The double fisherman's is an unlovely bulkier alternative exhibits much less, if any, creep. There are more and less symmetrical ways of tying it, but I've never read or heard anything about strength or stability differentials.  For rappel slings left in place, I think the double fisherman's is mandatory as a moral imperative. For personal slings and slung gear, it's up to the individual, as usual. 

Is there evidence for this is true for slings as well as cord? 

Are you sure they're kosher?

That's interesting. Now that I have sewn slings, rather than ones I've tied myself, the only regular use I make of a tape knot is when cutting a length of abseil tat and tying it. I very occasionally use it for reslinging an old cam or hex.

Hi

Needle Sports (I trust their advice) recommend:

for  tape            tape knot

for cord            double fishermans

for Dyneema    triple fishermans

Here's a couple of links:

https://www.needlesports.com/Catalogue/Climbing/Rock-Trad-Climbing/Cord-Tap...

https://www.needlesports.com/Catalogue/Climbing/Rock-Trad-Climbing/Cord-Tap...

That’s one of the good old discussions. Almost as good as the innie versus outie discussion.
The water knot is ok if you inspect it regularly for creeping, which it will do. The double fisherman’s is not only stronger; it welds itself and will never become undone. The tests have been performed long ago in the last millennium. Way before YouTube.

If your point is that my post constitutes bursting through doors already open, I'd agree. Tom Moyer's test results are now 25 years old.  But the comments here and elsewhere, as well as some tragic accidents in this millennium---Gary Falk's was in 2016---suggest that those doors are not yet open for all. Surely there is no harm in posting old information that doesn't seem to be well-circulated, as you yourself have just done.

Some point in the mid 90s... I had mostly self tied slings (using tape and water knot). Had done for ages, inspected and tightened them before climbing had decent tails. One day, I was talking someone on their first ever climb (Idwal slabs, Ordinary) I was on the last pitch before the ledge but near the ledge and I used a sling to extend the belay a little so I could sit in a scoop to belay. I was belaying them up to me when I saw the sling was totally undone, I was meticulous about the knots - no idea how that could've happened. I'd not been placing runners except maybe one or two to the side sometimes to keep the rope out of the big cracks so there was no runner between me and the second, if the second had fallen I wasn't in a position to have unexpectedly taken the fall we'd both have gone down the slabs from near the top. Obviously I quickly tied it back up, but that was the last time I used self tied slings, that was a hard lesson, my second was finding the "climbing" difficult and plausibility could have fallen.

DON'T TRUST WATER (tape) KNOTS, they will come undone at some point no matter how meticulous you are.

If you must use them, secure the tails with insulating tape (no the adhesive is fine on nylon and polyester etc, better that than coming undone, I don't care to debate the adhesive angle with you)

That's a pretty categorical statement - but can you prove it? How do you know your sling knot came undone totally on it's own? How can you be certain the knot didn't catch on something and lever open? Did you have tape or stitching on the tails? How do you know someone might have been absent mindedly fiddling with the sling at some point? Indeed how do you know someone wasn't trying to kill you!?

I re-slung all my first set of friends using water knots. I bounce tested them to tighten the knot and left tails long enough to wrap standard width duck tape around (50 mm is it?) and the tail protrude beyond the tape a little. I used them for years subsequently and never saw any evidence of the knots creeping. I've done similar with a few old Mamba quickdraws as well. I don't use them a huge amount but check them if I am taking them out and no evidence of knot creep after several years.

Many years ago (1976) so no reflection at all on current safety standards, I was volunteering at Outward Bound Aberdovey on a top-roped session at Tonfanau (not now called that I think - it's a single pitch outcrop from the beach). Kotted tape slings were used to extend the top anchors. They were Troll Supertape knotted conventionally with a water knot with long tails and duct taped as described above. I spotted one sling where the knot had moved so far along the tape that one of the duct tapes had passed right through the knot. The knot was now on a single strand of tape and the sling was held together by the two duct tapes alone. Urghh! I couldn't really believe it had happened, but it had.

Martin

I must confess I’ve no interest in using cams with home made slings / cords.

I know some people like them and of course it prolongs their lifespan but they are messy on your harness, not as nice to use and for me just not as psychologically positive when I’m above and shaking.

Thanks for the discussion folks.

I've done hours of research into the use of double-fishermans for webbing as I want to be feeling secure that anything I take out to the crag is safe for me and my climbing partners.

I've seen the double-fishermans suggested as a knot for webbing in the AMGA Single Pitch Instructor Manual (which I'm guessing is about the same as our RCI instructor) which would seem to be a pretty authoritative source.

I also found an old CAMP Tricam manual which suggested that tricams should be reslung with webbing tied with a grapevine bend.

Rock Climbing: The Art of Safe Ascent (2021) has the following to say on the topic:

>A double fisherman’s knot is tricky to tie neatly in nylon webbing and requires a longer piece of sling. Once weighted and pulled snug, the double fisherman’s is very secure and will not loosen. It is also difficult if not impossible to untie after heavy loading.

>The double fisherman’s knot is a very secure way to tie nylon webbing into a loop, although it requires more material length than the water knot. The knot itself uses an additional 26 inches of sling, compared to the water knot, which takes about 19 additional inches of sling to tie. The double fisherman’s is also nearly impossible to untie once it’s been seriously weighted.

AMGA Guide - https://i.imgur.com/5cz40x6.jpg

Wasn't the Water knot originally called the Frost knot after the American climber, Tom Frost?

Honestly I've climbed since 1972 and never heard of a water knot, it was always a tape knot and yes I have heard it called a Frost knot. 

I've just looked at my old tape knotted slings. The one I draped round the crozzly jug on Right Wall in 1989 still seems pretty sound if a little frayed.

Yes, this thread is the first time I've ever heard it called anything other than tape knot.

No, the Frost not was a variation on an overhand loop that simultaneously joined to ends and created a clip-in point.  One tail was inside the loop.  The application was to the tied aid slings we all used BITD, reducing the number of knots typically used and making everything cleaner. The Frost knot was at the top of the ladder and the loop was where the sling was clipped to gear.

In the US the terms were water knot and ring bend.  We don't use the term "tape" for flat webbing and so "tape knot" has never been used.

I tied these tape knots in rigid stem friends sometime around 1988. They’re retired now, but saw a lot of action over more than 30 years. I’ve never had to touch the knots. Thinking back I’ve never had any issues with tape knots whatsoever. Guess I must just be lucky.

Same here although your knots look a tad sloppy to me! Here's my original sling, it would be virtually impossible to undo.

Rgold thanks for the explanation of the Frost knot.

As for putting sticky tape around the ends of a tape knot I never did this. It serves no purpose and may well obscure a gradual loosening.

Surely the opposite.

Well we respectfully disagree. If you need sticky tape to prevent a knot coming undone it's a pretty crap knot! 

Not to prevent it coming undone. To make it obvious if it is creeping.

Interesting discussion - in over 30 years of climbing (and 20 of hanging round UKC!), this might be the first "proper" discussion I've seen on tying Fisherman's bends in tape.

FWIW, I've only used tape/water knots (strictly a bend) in tape (end even then rarely), but I've always been aware of the potential for them to creep and made sure that I've tied them with long tails. I have actually stitched a couple of them and there's been a suggestion of creep as a result, but might just have been the knot tightening.

I was interested in the section in the YouTube video that rgold linked where the knot came undone very easily when hooked - I've not seen that suggested as an issue before, probably because I only really use sewn slings and carry cord to use as tat, as it's usually easier to thread.

These days, I think I've only got tape knots on some large Hexes, where the holes are large enough to get tape through and the knot is actually inside the Hex, which has advantages on using them.

I'll bear the Fisherman's bend in mind for future use, though. Good to read your post about them.

There was one of these knots on the cover of Ron James original selected Welsh Climbs guide.

Walter Siebert did a you tube vid on tape knots and how unreliable they are and gave a safer option.

The mechanism by which they loosen is called cycle loading - on off pressure over time. There are a lot of documented fatalities with specific tape knot failures in alpine climbing. 
 

check out Walter Siebert