Crevasse Falls: do brake knots work?
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- čas přidán 10. 10. 2017
- In September 2012, the French national mountain guides’ school carried out a research project into crevasse falls.
We tested the effect knots in the rope have on the ease of holding a fall. These knots are called ‘Brake Knots’.
So do they work? - Sport
This is a wonderful video, it's so good to see solid data on critical climbing information like this. Thank you very much for making and posting!
Thank you for doing this research.
Great content! Thank you very much for sharing it.
really awesome work
Really well done, thank you.
Merci beacoup guys, great research!
Great video!!!
Superb - thank you! 🙏
Thank You!
THANK YOU!
Awesome work! Very interesting and nice to know! I guess if the one in the crevasse was not able to haul themselves out (unconscious, broken arms, etc) you would need to do some knot passes when hauling them out. I guess that wouldn't be too bad if you had the right equipment with you.
Best to just descend on another rope and make a new system for hauling.
nice work
Je comprends votre contribution à la sécurité en montagne et qui nécessite l'usage de l'anglais. Mais vous abusez. L'anglais est traduit ... en anglais, un sous titrzge pour le moins en Français est attendu. Je présume comme école nationale Française produisez des supports au moins sous-titrés en Français. Merci pour vos supports passés et avenir, bien cordialement.
WILL THE KNOTS PRESENT DIFFICULTY WHEN HAULING OUT?
thanks for the experiment. but wouldn't be a pain in the neck when you hual the victim out as you'll have to untie the knots?
For the brake knot wouldn't a butterfly or some variation work better since the angle of pull from the knot would be more in line?
It should be bulky enough, butterfly is twice the less as the figure 8 knot
@@danielpghe You mean the Butterfly is half the size of the figure 8 I assume..
It would, a butterfly also isn't a flat knot so it would bite in better.
Do the knots complicate the actual rescue procedure at all?
Yes they do. During the mouflage (hauling?) you have to stop the hauling every time you come to a knot and have to do a little trick to pursue. There are plenty of tutorials about these technics on CZcams, go check! :)
If you are using knots in your rope, how do you either ascend the rope to get out or get hauled out using a pulley system?
Wont the knots impeded you ascending the rope and also act against a pulley system?
Yes they will so a haul system would need to use the free section carried in the rescuer's coils or a separate rope
Knots are certainly a big hindrance for hauling someone out of a crevasse, less so for self-rescue. But in any case the most important thing is to stop the fall!
Brake knots are particularly helpful when there are only two people on the rope. Each should carry a reserve of rope which is at least as long as the distance between them. With a 50m rope it's possible to have 15m between each person (excluding knots) and slightly more being carried as a reserve. Once a snow anchor has been constructed, the reserve can be thrown to the person in the crevasse.
You don't! Firstly NEVER use more than half a rope length between you, or between the first 2 in a group. The person on top make the anchor in the normal way (should be easier now as the knots are taking some weight) Assuming you've shouted for help etc and nobody came!! As climber you'd usually be climbing with 2 ropes, be it Half's/doubles or twins, the person at the rear takes the second rope in the rucksack (only use one on the crevasse) the person in front takes slightly more than half the rope in use, in the form of coils (or what ever method they chose). If the front person falls in then the rear person uses the second rope and lowers it to the one in the hole via an "assisted hoist". Basically you drop a loop down with a crab, they attach and you haul them up via a 2:1 system with a traxion/prussik on the anchor as normal. If the rear person drops in then the front person makes the anchor and sets up a pulley system in the normal way EXCEPT its on the half of the rope they have in coils. They the untie and secure themselves to the live rope or anchor. They then lower the free end of the rope with a crab on a figure 8 knot down to the one in the hole who clips in and you haul in the normal way. If the person is rendered incapable by the fall then the person on top can use the free rope/end to abseil down to render assistance. If only carrying 1 rope then the person at the rear takes the coils and you use the second method. You can only hope the rear person doesn't fall in, or life gets a whole lot more difficult!!!
Cool, thanks guys.
How to untie the knots in a pulley system is presented by Petzl here: www.petzl.com/BE/en/Sport/Crevasse-fall--hauling-on-a-rope-with-knots