Which knot should you use for joining ropes?

The first part of this video shows how knots in Dyneema can pull apart easily when loaded. Dyneema is much more slippery than nylon, and traditional knots cannot be relied upon.
The second part of the video deals with tying abseil ropes together.

[@forestwealth]

For perspective, belay forces are generated with sudden falls, rather than sustained 1800lbs pulls. It would be best to see slippage tested on a proper EN892 fall tower as well. In particular for dyneema, HMPE fiber is thermosoftening and sudden forces cause friction and extra degradation. As the DMM 2012 experiments showed, dyneema tape performed much differently in the load cell pull than the 80kg fall tower. Also curious to see the Paketknoten bend tested. Apparently DAV classes are advocating that on abseil ropes now. It has a flat profile for retrieval and appears resistant to capsizing. Claim is almost as efficient as the triple fisherman in strength and much easier to untie. Btw, English speakers might translate your device more specifically as a load cell. It is certainly a type of dynamometer and correct to call it that. Just like it would be correct to call a bicycle a 'vehicle', but less typical.

[@KK-TO]

Great objective tests with regards to loading. I think the recommendations were also straightforward and clear.

[@KillroyX99]

Why not kN?

[@eloimauri6235]

Right? Who uses dN? The standard is kN, there's no need to over-complicate things...

[@rafaelthetall]

can you guys make trials with the Rosendahl/Zeppelin bend and the farrimond hitch?

[@BowlineDandy]

No

[@TheAttribut]

Nice educational material but I found confusing the bit around 2:29 - OHK adequate for retrieving your ropes...Why would we conduct rope retrieval tests against hundreds of dekanewtons?

[@evertongatto8944]

can the ropes be tied by the double overhand knot?

[@ananda_miaoyin]

Leave it to the French to use Decanewtons instead of anything else that is more common. Good testing, though.

[@lalibertenordsud]

How about a threaded figure 8 to join 2 ropes?

[@trollmcclure1884]

Yeah, it's never used like this. And what about two bowlines for ropes of different thickness. I'd like to see them perform. With a figure 8 stopper knots. That's how I'd like to join them. This or fisherman's with a figure 8 stoppers.

[@chiaraiodice4254]

Habituée à vos m’aider de vos tutoriels, je suis assez déçue de ne voir que des versions anglaises... des sous-titres français ne sont même pas disponibles. Dommage pour une institution française; le vocabulaire étant tout de même technique les sous-titres seraient appréciés ! Merci quand même pour les vidéos précédentes de super qualité et surtout très utiles.

[@armatacalanca962]

kzbin.info/www/bejne/hF7NdmB6lpmDZ7c

[@chiaraiodice4254]

@@armatacalanca962 Merci :)

[@vbregier]

Why don’t you test other joining knots, such as square, sheet, alpine butterfly, or zepplin bends ? You say that all knots slip, but you only tested a few knots…

[@martincotebrazeau]

Decanewtons, I'd like the results in stones so people can compare easily to units used in climbing, like the one that is on the side of carabiners..

[@tomseeley6188]

100 daN (Decanewtons) is equal to 1 kN ( Kilonewtons)

[@jeroenfeher8107]

Just to add to this, even if I'm late to the party. Stone and Kilograms are measures of mass while Newtons are a measure of force. You could express at which mass, hanging statically, a rope would fail but this isn't that useful under dynamic loading conditions. It is easily converted to the mass required to generate the forces of such a static load though.

[@gilesosborne3582]

@@jeroenfeher8107 for most non-scientists or those who don't fully understand the difference between weight (force) and mass...1 dN ~-=1kg in this situation...let's not confuse and alienate those who wish to learn basics for safety :-) :-) I still buy apples etc in kg as their "weight"..I'm not going to be a pedant to the grocer :-) Of more intesrest to myself and others is the relative % strength of knots compared to rope rating.....Fig 8 better, but can't get the bugger undone after load vs bowline, alpine hitch vs dropper loop etc...horses for courses! :-)

[@chankslunks]

Figure 8, is good when is loaded

[@KillroyX99]

A dynamometer measures power. You are measuring force, so a more correct term would be force gauge. The industry has perpetuated this error.

[@Batmane812]

but can measure force and torque also w radius taken into account

[@mikec4229]

‘Rappel with dyneema...’ Ok, then

[@frosch161]

Its like washing your feet with lava instead of water 🤦‍♂️

[@adventureswithfrodo2721]

I know you are into metrics and all that but reporting In decinewtons is stupid. Just do it in kilonewtons

[@polimorfonuclear]

Very confusing video. It should be a do or dont knot video. In safety materia you must go with yes or no answers

[@christopherrowley7506]

Unfortunately truth depends on context. What knots are safe and unsafe depends on the kind of rope you are using and what you are using it for, which was the purpose of the video.

[@adventureswithfrodo2721]

Really reporting the strenghtcas 200dN is poor as it is 20kN. So not sure why. It why not.0.02TN. Sorry but a degree in chemistry just makes me question your use of the metric system. Hardware is rated in kN.

[@beyondthepale2023]

Meaning you don't like the metric system or that the French , who invented it, or the manner in which they have used it?

[@Batmane812]

its confusing I know, I would've preferred kN but 200dN is only 2kN