Abseiling with grigri and prusik knot

[peds]

11 minutes ago, Joris said:

 

I also make knots underneath me every 3 or so meters just in case. Is that a good idea since i’m using a static rope?

"Catastrophe knots", as they are sometimes called in the "roped soloing" rock climbing community, are almost always not worth the hassle as long as the other parts of the system are sound. A belay device and a prusik should really be more than enough.

[Joris]

4 minutes ago, peds said:

That sounds like a hell of a lot of faff. I assume you've got one hand on the grigri and one on the lower rope? Have your prusik on a shorter loop, below the device, and milk it at the same time as you descend with your downhill hand.

Is there an instruction video of this specific technique?

with the prusik underneath the grigri, and the grigri slips, isnt it going to take the prusik with it on its way down? 
thanks for replying!

[peds]

Here's a caveat: I don't use a grigri, I've never enjoyed them. They don't solve a problem I've ever had. But the theory is the same for any belay/rappel device.

You need your prusik on a loop that doesn't reach the bottom of the device. This can be achieved by clipping it to a leg loop instead of your belay loop, or by extending your device up a little by clipping it to a short sling, which is larks footed to your belay loop. In rock climbing, I would always do this with my cow's tail, or personal anchor, with a knot tied halfway down it, so the belay device is halfway along the sling. Like this, your device is far enough away from your prusik knot to not interact with it, but close enough to manipulate. 

Now, this is where simple devices like figure-of-8s, atc, guide plate, reverso, whatever, are better than the gri gri: the hand that is milking the prusik on the downhill rope is also controlling the feed of rope into the device, leaving your other hand free to comb your hair or roll a spliff or sort out tangles in the rope, whatever you want. You don't have this luxury with the grigri, which needs a hand on it all the time you are descending. 

 

Edit: Petzl do hundreds of useful infographics for using all of their products and the situations you'd use them in. Just Google image search "Petzl rappel prusik grigri" and "petzl rappel prusik reverso" and you'll get a good idea of what's going on. 

Edited April 5, 2022 by peds

[Steve Bullman]

35 minutes ago, Joris said:

Is there an instruction video of this specific technique?

with the prusik underneath the grigri, and the grigri slips, isnt it going to take the prusik with it on its way down? 
thanks for replying!

Yes it is, don’t do that 

[Joris]

16 minutes ago, peds said:

Here's a caveat: I don't use a grigri, I've never enjoyed them. They don't solve a problem I've ever had. But the theory is the same for any belay/rappel device.

You need your prusik on a loop that doesn't reach the bottom of the device. This can be achieved by clipping it to a leg loop instead of your belay loop, or by extending your device up a little by clipping it to a short sling, which is larks footed to your belay loop. In rock climbing, I would always do this with my cow's tail, or personal anchor, with a knot tied halfway down it, so the belay device is halfway along the sling. Like this, your device is far enough away from your prusik knot to not interact with it, but close enough to manipulate. 

Now, this is where simple devices like figure-of-8s, atc, guide plate, reverso, whatever, are better than the gri gri: the hand that is milking the prusik on the downhill rope is also controlling the feed of rope into the device, leaving your other hand free to comb your hair or roll a spliff or sort out tangles in the rope, whatever you want. You don't have this luxury with the grigri, which needs a hand on it all the time you are descending. 

 

Edit: Petzl do hundreds of useful infographics for using all of their products and the situations you'd use them in. Just Google image search "Petzl rappel prusik grigri" and "petzl rappel prusik reverso" and you'll get a good idea of what's going on. 

Thank you for your time!

really informative

[benedmonds]

Back in my rock climbing days (20+years ago) we were taught to back up the descender with a sling or even a shoe lace tied with a prusik knot, if you didn't and for some reason lost consciousness or dropped the rope you would end up descending freely.  You could still rappel with one hand as you hold the prusik knot as you tend the rope.   It took me a while to get my head around tree climbing where we just relied on rope on rope.    

 

The knots every 3m sound like a complete waste of time, you could have one at the end of the rope if you really needed. 

 

The op really should get some training as they seem to be making it much more complicated than it needs to be.  

[peds]

While we are on the subject, here's another plus point for having your prusik below your device. When you are setting up to rappel, put your prusik on the rope first, before your device, then you can pull through enough slack to feed into the device easily, without the weight of your whole rope below you.

[Joris]

1 hour ago, benedmonds said:

Back in my rock climbing days (20+years ago) we were taught to back up the descender with a sling or even a shoe lace tied with a prusik knot, if you didn't and for some reason lost consciousness or dropped the rope you would end up descending freely.  You could still rappel with one hand as you hold the prusik knot as you tend the rope.   It took me a while to get my head around tree climbing where we just relied on rope on rope.    

 

The knots every 3m sound like a complete waste of time, you could have one at the end of the rope if you really needed. 

 

The op really should get some training as they seem to be making it much more complicated than it needs to be.  

Hi, thanks!

time really isnt an issue because no one has to pay me 😁

So I dont mind making a knot every 3 meter.

also i’m climbing a static rope, so imagine i’m free falling 8meters or so and the knot on the end of the rope saves me. That would hurt really bad because of the rope being static, not dynamic, isnt it?

[benedmonds]

18 minutes ago, Joris said:

Hi, thanks!

time really isnt an issue because no one has to pay me 😁

So I dont mind making a knot every 3 meter.

also i’m climbing a static rope, so imagine i’m free falling 8meters or so and the knot on the end of the rope saves me. That would hurt really bad because of the rope being static, not dynamic, isnt it?

I don't understand why you need knots, unless you run out of rope? Up until a few years ago all tree climbers used to ascend and descend was a rope with some type of friction hitch. No backup or anything.

[Joris]

11 minutes ago, benedmonds said:

I don't understand why you need knots, unless you run out of rope? Up until a few years ago all tree climbers used to ascend and descend was a rope with some type of friction hitch. No backup or anything.

Is it more dangerous with knots?

I just make them to prevent a bigger free fall