Would girth hitching a longer prussic into the guide loop of a tube style belay device be an acceptable backup for a rappel?

Not Hobo Greg wrote:

So if the keeper loop breaks, isn’t the rope still held in place by the locker? 

This is true only if you are still holding the brake strand. I tested it without the belay device unrated loop, and it is no longer hands-free. However, I still think it would be preferable over not having a backup 

OP's suggestion will do one thing.  After the WEAK keeper wire pulls out of the ATC (it happened to one of mine on its first use), it will ensure that the ATC itself doesn't slide to the end of the rope. The unfortunate climber OTOH... zip...boom.

Let's clear something up - 

OP did no  suggest using keeper loop for attaching prusik.
His diagram clearly shows using ATC-guide type of device, prusik is hitched to the guide loop
His video clearly matches diagram

amarius wrote:

Let's clear something up - 

OP did no  suggest using keeper loop for attaching prusik.
His diagram clearly shows using ATC-guide type of device, prusik is hitched to the guide loop
His video clearly matches diagram 

Let’ s clear something up. We know that.

Since the rope is no longer being loaded but the device still is, the keeper loop ends up supporting the load.

Cole Lawrence wrote:

Let’ s clear something up. We know that.

Since the rope is no longer being loaded but the device still is, the keeper loop ends up supporting the load.

I see, my bad.

In regular autoblock/prusik below device setup, ATC is attached through the rope and carabiner to belay loop, all of the weight is being transferred to to belay loop via rope and carabiner; autoblock/prussik only gets a few pounds. 

In the suggested use, all the weight is being transfered to ATC, which is help by carabiner hooked to keeper loop, no rope in the system.

Not Hobo Greg wrote:

 But when said keeper cord breaks, the whole system is still intact. You’d only fall if you didn’t have your hand on the brake (and even then,  only if the friction hitch slips). In no way am I advocating using this dude’s method, but I do think there’s a misconception regarding what would happen next if the keeper cord breaks. 

I agree

please just don’t consider doing this. It is not even an option. Its not a back up. Its a trap! Its literally a gumby booby trap that could leave you stranded down the lines with no means of ascending and no possibility to progress capture with your device and your prusik stranded above you - assuming that you are able to arrest your fall (like in the event of needing the back up, which is the purpose of the back up).  

no offense - seriously. But this is the winner of the best-worst idea that at first seems ok. 

Greg, I'd start by saluting your curiosity and willingness to try stuff out by yourself. This is, all things considered, a good thing.

HOWEVER.... to that great quality you should probably consider adding careful consideration of the perspective of people who have (likely) much more experience than you do. Points mentioned above are very valid. This *works* but is likely to be sketchy as fuck if it actually comes into play in a real situation, while you're mid-cliff just after having pass an overhang an you, for whatever reason, let go of the break strand. All sorts of things could happen, and this system reliably catching you and preventing you from zipping to the bottom is one of them, but maybe not even the most likely one.

I get that this is your idea, and that for that reason alone you probably like it, but don't get married to an idea just because it's yours... especially when it pertains to technical climbing setup for which there are already good proven solutions.

Not Hobo Greg wrote:

 But when said keeper cord breaks, the whole system is still intact. You’d only fall if you didn’t have your hand on the brake (and even then,  only if the friction hitch slips). In no way am I advocating using this dude’s method, but I do think there’s a misconception regarding what would happen next if the keeper cord breaks. 

I don't think so. If the keeper loop breaks and one doesn't have a hand on the brake end of the rope the climber and locking carbiner will plummet as the rope runs. Only difference the "backup" makes is whether the ATC stays in place or comes along. The backup is not attached directly to the climber. 

Not Hobo Greg wrote:

 But when said keeper cord breaks, the whole system is still intact. You’d only fall if you didn’t have your hand on the brake (and even then,  only if the friction hitch slips). In no way am I advocating using this dude’s method, but I do think there’s a misconception regarding what would happen next if the keeper cord breaks. 

Well, if you keep your hand on the brake strand at all times, there's no point in having an autoblock.  An autoblock-based back-up HAS TO be 100% solid if/when that brake hand is not there. OP's proposal is not.

Right, it's not actually a backup. 

Or more specifically, the "backup" (ie the last/weakest link before failure while hands off) in that system is the keeper loop on the ATC. 

Go rig it with the carabiner outside the keeper loop and let go. Do it near the ground :-)

Not Hobo Greg wrote:

 But when said keeper cord breaks, the whole system is still intact. You’d only fall if you didn’t have your hand on the brake (and even then,  only if the friction hitch slips). In no way am I advocating using this dude’s method, but I do think there’s a misconception regarding what would happen next if the keeper cord breaks. 

Actually after the keeper cord breaks you are connected to a bight that can be made biggervery easily by the rope feeding from below through the the device and you falling with the growing bight. 

jdejace wrote:

Go rig it with the carabiner outside the keeper loop and let go. Do it near the ground :-)

Yes, this.   Also what problem is the OP trying to fix with this system? what's wrong with the standard backups for repelling?  Why are people continually trying to find clever ways to make shit sketchy AF?

Not Hobo Greg wrote:

Yes it is: backup is attached to ATC, ATC is still attached to rope via the locker. They would only plummet if the friction hitch slips. You won’t find me using this method but we should at least be able to agree about the facts.

Yea sure the ATC is connected to the rope but you are no longer connected to the atc. As the rope runs you will fall and die.  Not hobo gred you are wrong simply and pls don’t die trying this  
to every one else  this is wrong and you can die doing this 

Gregory Fanarisios wrote:

Like this

Wait...trying to understand....

How are you guys getting that he is not connected to the rope, or the ATC, if/when the keeper loop breaks from the ATC? This looks like the ATC is rigged with the rope, through a locker on a belay loop. Maybe facing an awkward direction, but minus the additional prussic, what's any different than just a rappel with no backup?

Thanks! 

I sure as hell bow to Mikey as reply number one (and all the rest of you), but I'd still like to understand this particular bit of it.

H.

Tradiban wrote:

Hold on fellas, every legendary innovator has a few failures along the way to greatness.

What failures have you gone through to your access your "greatness"?

Old lady H wrote:

Wait...trying to understand....

How are you guys getting that he is not connected to the rope, or the ATC, if/when the keeper loop breaks from the ATC? This looks like the ATC is rigged with the rope, through a locker on a belay loop. Maybe facing an awkward direction, but minus the additional prussic, what's any different than just a rappel with no backup?

Thanks! 

I sure as hell bow to Mikey as reply number one (and all the rest of you), but I'd still like to understand this particular bit of it.

H.

He is connected to the rope , but not the device , son the keeper breaks he is connected to a bight  through a prussicked on device. So if that bight is weighted he falls as the rope is pulled through the device from  below. 

This is a great candidate for backyard testing. Go try it; instead of breaking your keeper cord, just make a point not to clip it.

It's not just that the keeper cord will break --- a rappel device with no keeper cord is still a rappel device. It's that the keeper cord breaking is catastrophic because the rest of the system is dogshit.

When you load the keeper cord and break it, you're also fixing the rappel device to that section of the rope, because your prusik activated. When the rappel device is fixed, it doesn't follow you down the rope; you just ride a huge bight until you hit the deck. Compare this to the behavior of a rappel device when it isn't fixed and you let go: unless it catches on something, it'll follow you quite happily down the rope, whizzing the whole way. 

This system is dangerous because the "third hand backup" makes it even more dangerous to let go than a comparable system, INCLUDING a system with no backup at all. It's the opposite of a backup. You're adding a failure point for no reason.

Seriously, go try this in your back yard without the keeper cord clipped. Your eyes will be opened.

Pat Light wrote:

This is a great candidate for backyard testing. Go try it; instead of breaking your keeper cord, just make a point not to clip it.

It's not just that the keeper cord will break --- a rappel device with no keeper cord is still a rappel device. It's that the keeper cord breaking is catastrophic because the rest of the system is dogshit.

When you load the keeper cord and break it, you're also fixing the rappel device to that section of the rope, because your prusik activated. When the rappel device is fixed, it doesn't follow you down the rope; you just ride a huge bight until you hit the deck. Compare this to the behavior of a rappel device when it isn't fixed and you let go: unless it catches on something, it'll follow you quite happily down the rope, whizzing the whole way. 

This system is dangerous because the "third hand backup" makes it even more dangerous to let go than a comparable system, INCLUDING a system with no backup at all. It's the opposite of a backup. You're adding a failure point for no reason.

Seriously, go try this in your back yard without the keeper cord clipped. Your eyes will be opened.

Thanks! I get why it's bad. But, I'd not be able to talk myself out of not having a hand on the rope under the ATC, so it would do me zero good with the prussic above, anyway.

And, yes, if you let go below, broke the keeper, and that brake hand couldn't get the rope....yeah, I can see that now, thanks! 

It's good to understand the whole picture! 

Best, Helen

I'll also point out that while the average climber would do well to put her third hand below the rappel device, a lot of old-school rescue folks will put a VT prusik above the rappel device, totally bomber. That was another theme of this thread that I found puzzling (not from Helen, but in general): "Prusik above the rappel device" isn't the reason this idea is dangerous, and isn't even necessarily a problem. "Prusik fixed to the rappel device" is the issue.

In summary: A lot of y'all should be spending more time two feet off the ground in the Backyard Technical Institute.