Hacker News Reader

Comment by exabrial | Hacker News Reader

All I know is a triple fisherman's is nearly impossible to untie in 5.6mm UHWMPE after taking a whip on a sling made out of it. It's sort of comforting have the rock hard knot; it'll break the cordelette before untying. Interestingly, an unweighted one is pretty simple to untie!

View on HN

HowKnot2 have been making empirical testing videos on climbing knots and gear which have proved fascinating and often unintuitive.

If you'd like to see a break-strength test comparing single, double and triple fisherman’s knots, you might enjoy: https://www.youtube.com/watch?v=5CAjUi47QMY

For reference, a 100kg climber is unlikely to be able to cause more than 14kn of force on a dynamic rope, (in reality, significantly less,) even if they go out of their way to find the worst case fall-scenario. Most belay loops are rated at 15kn, human bodies start breaking at 8-12kn and HowKnot2 says that a double-figure-8 (the standard rope<->harness knot) all break at around 14kn https://www.youtube.com/watch?v=g4CVFRE0pRg&t=500s

The double-figure-8 is pretty rare in climbing, it's the regular figure-8 loop that's used. Sometimes called a "figure-8 follow-through" to describe the tying method. The "double-figure-8" has two loops, it's not at all commonly used in climbing. Mostly just for some improvised rescue situations as part of an improvised harness to replace a damaged harness's leg loops.

yup, it's also great for fixing and equalizing a rope to a sport anchor for top rope soloing, etc. https://www.alpinesavvy.com/blog/fixing-a-rope-two-knots-to-.... Super easy to adjust/equalize.

Yep, you're totally right. I had double and triple on the brain from the Fisherman's; standard climbing knot is but a simple figure-8.

Do you by chance mean 5kn, not 14kn? I believe thats the threshold of injury. I believe > 8kn is pretty much certain death, but I don't have a direct source.

Actual tests:

* https://web.archive.org/web/20250712222155/https://www.howno...

* https://web.archive.org/web/20240125125133/https://www.howno...

The anchor experiences greater force in a fall than the climber.

Ah I see now, "force experienced by rope" not "force experienced by climber" :)

> a double-figure-8 (the standard rope<->harness knot) will break at around 14kn

My understanding (based on some training aeons ago) is that the figure 8 knots prevalence for tying in is not due to that strength - but instead because it is easy to check, hard to back through/untie during usage, and strong when mis-tied (ie errors are made and not caught).

It's not often I come across a comment that I wouldn't understand any less if it was in a language I don't speak but I think this one makes the cut.

Holy topic-specific terminology, Batman!

Related: "How I, a non-developer, read the tutorial you, a developer, wrote for me, a beginner" [0].

[0] https://news.ycombinator.com/item?id=45328247

Haha, yes!

> All I know is a [knot used to join a length of rope into a circle/loop, performed three times) is nearly impossible to untie [when tied with large-diameter polyethylene plastic rope] after [falling (while climbing) and being caught by the loop I made to take load] made out of it. It's sort of comforting have the rock hard knot; it'll break the [loop itself, structurally] before untying. Interestingly, [if you don't tighten the knot by dropping bodyweight from a height on it like I did, they're] pretty simple to untie!

This is amazing.

Thank you!

All we need is a fisherman-toplogist, and we can perfect the incomprehensibility of the discussion on particular knots.

This may help.

https://m.youtube.com/watch?v=TUHgGK-tImY

Or may not.

You probably know this already if you climb, but in east germany and the czech many areas mandate knots as protection, jamming them in cracks: https://www.climbing.com/travel/soft-stone-rigid-ethics-elbe...

Supposedly cams and nuts damage the rock. Pretty gnarly stuff. And it's often sandy off-widths as well...

Reply on news.ycombinator.com