Petzl said to NEVER do this

Agreed with the other risks, of course. Hope you friend was ok and thanks for the info!

Brandon Newton

So on the person 4kn is a lot for a lead fall. Often times it's just 2kn. A top rope fall is not very much more than the weight of the person with a dynamic rope or 2x their weight with a static rope. But that's with a rope going all the way up and back down to the climber. If you are top rope soloing, if you keep the slack to a minimum, and are 160lbs like me, you might get between 1-2kn. Look at this video how far I had to fall to generate just 2kn. The bigger falls near the anchor is when the forces got sketch but just make sure you don't have a bunch of slack in your rope and use a dynamic rope and it's super good enough.... (as long as you don't get your shirt stuck in the teeth like my friend's buddy had happen and you fall 100 feet to the ground. There are other risks with soloing fyi but the forces aren't a problem if you manage your rope).

Do you know what the average force is for a top rope fall? I'm considering top rope soloing using these devices and would be interested to know average forces to better understand the risk involved. Lead falls are 3–4.5kn on average correct?

Brandon Newton

@Ryan Those camming rope grabs are probably just as inconsistent as prussiks. But because they are certified in theory would only start slipping above that 4Kn mark. I have quite a few ideas, but from a rope access perspective. For instance, how much earlier would the toothed grabs damage old and used rope. Used offshore on rigs in salty environments..

@Nik Aha, so you mean teeth don't matter for the certification? That is true. As long as the device conforms to the standard, it doesn't matter how. But for us, in the practical world, it does matter. Device with teeth, cut ropes. Devices that cam usually slip. But sometimes tear the rope too but at higher kN. I remember seeing a video of the Petzl Rescuecender that tore the rope at 7kN I think it was. I also remember the old Shunt was EN567 but that slipped anywhere from 2kN or up depending on rope diameter and state. I had to look it up when you mentioned that 4kN hold and up I see it doesn't have the EN nr anymore and all the wording has changed of what a Shunt is. It is not a rope clamp anymore haha. Teeth are not bad under normal use as long as we are aware to prevent shock loads to them. Especially in two person rescue systems.. And this video just goes to show that if it would happen... We have some leeway before it becomes catastrophic. Well, with a EN892 rope in a dynamic fall and in lab slow pull test that is... I'm curious what those same dynamic drops would have done on a EN1891A rope. How much smaller the drops would have been before Ryan would say "I am not doing this sh*t for science! It hurts"

Now I'm extra curious. I might make a follow up video after collecting these other devices people are asking about in the comments and what you brought up.

EN 567: https://www.scribd.com/document/522012946/EN-567-en. paraphrasing the hardest test: Take the smallest diameter rope it is rated to, slow pull it to 4kn, remove, no visible damage to the rope. That said, you sent me down a rabbit hole of pull test videos. I'm not worried about teeth in a TRS situation where I keep the rope from getting slacked, but I'd be curious to see similar drop tests for a camp lift or rescuecender.

How come teeth don't matter? Devices with teeth damage a rope sooner or at a lower force than a device without teeth right? Just compare a Croll or Basic to a Rescuecender. All of them are EN567 and EN12841B, but the toothed device damage the rope way sooner and a camming device tends to slip instead of cut the rope. Which standard are you referring to?