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

Wondering if this is an acceptable backup for a rappel. 

Like this

Maybe, but...why?

Why? That looks sketchy AF. I bet would hold but you you’d be removing some of the friction of the rap device. Just do the system like a normal person.

No. The load would be placed on the keeper loop. 

C L wrote:

No. The load would be placed on the keeper loop. 

This.   I just set this up in my basement and if you went hands free or there prussik accidentally catches in that set up all your weight is on the unrated keeper loop. 

• No, as others have said the weight would be on the keeper and after that broke the rope would still slide through. Plus friction hitches above the belay device are not ideal for a number of reasons, your friction hitch should go below the extended device. The way you have it in your picture wouldn't work with a closed loop without a carabiner. 

DrRockso RRG wrote:

• Plus friction hitches above the belay device are not ideal for a number of reasons.

Can you elaborate?  I've had the debate on several occasions and my conclusion is having it below your device (device on an extended rappel) is more convenient/comfortable to use.

But, I don't really know the other reasons.

Gumby King wrote:

Can you elaborate?  I've had the debate on several occasions and my conclusion is having it below your device (device on an extended rappel) is more convenient/comfortable to use.

But, I don't really know the other reasons.

For me, it's that the mechanism of having it below the device is that it both locks the device and it hangs on the rope itself.... if the knot is above, than it's the sole element keeping you from going down the rope.   This is why I generally have my device extended and the knot directly on my harness.

DrRockso RRG wrote:

•  The way you have it in your picture wouldn't work with a closed loop without a carabiner. 

Bingo, that’s what I was missing 

Gumby King wrote:

Can you elaborate?  I've had the debate on several occasions and my conclusion is having it below your device (device on an extended rappel) is more convenient/comfortable to use.

But, I don't really know the other reasons.

There is potential to have your hitch get weighted and be unable to unweight the hitch to continue the rappel. As a third hand below your device the hitch need only hold the amount of force your hands would, vs. Above it needs to hold your whole body weight. 

DrRockso RRG wrote:

• . The way you have it in your picture wouldn't work with a closed loop without a carabiner. 

For pure discussion/puzzle solving purposes, this is not true.   He can have it as shown.  

• Girth hitch your prusik to your belay device. 
• Tie prusik to rope (with ATC attached)
• Clip rope through ATC and rappel 
• Risk death or disfigurement due to fucked up system

I suppose that's true given a long enough loop to fit the whole atc through. Sounds like a big pain in the ass though if the whole point of this was to keep things simple. 

You can also wrap the Prussik, pass the end through the guide loop and then pull the ATC through to make the girth hitch. Kinda like this. (before you thread the rope, obviously)

https://youtu.be/KYu0mxfEuK0?t=25

And no, you shouldn't do this because YGD, or really put any backup above the device. A backup above the device is holding your entire body weight. Below the device is just holding friction on the belay device. Think of how much strength it takes to hold your buddy's body weight with an ATC vs without. 

Following up on my original post: I tested the concept and it works! I would prefer a slightly longer prussic to add another loop, but the system seems to be functional.

Edit: apparently if the prussic locks up, the wire line on the belay device is taking a significant load. If you were unconscious and took a big fall, this system could fail. I probably won’t be using this at the crag. 

I’d recommend  watching your own video extremely closely.  All of your weight is resting on the thin black cable coming out of the ATC (like others have stated).  This part of the device isn’t rated for a live load.  Your suggested system is extremely dangerous and in no way should ever be used.  You are setting yourself for a serious life threatening incident.

Gregory Fanarisios wrote:

Following up on my original post: I tested the concept and it works! I would prefer a slightly longer prussic to add another loop, but the system seems to be functional. 

Did you seriously not read any of the posts telling you that it’s dangerous and why it’s dangerous?

Gregory Fanarisios wrote:

Following up on my original post: I tested the concept and it works! I would prefer a slightly longer prussic to add another loop, but the system seems to be functional. 

Speaking for all of my Gumbies and soon-to-be Gumbies...  PLEASE Take this video off of youtube.  Jesus, that is sketchy AF!.

This is gonna be the new standard comparison for terrible, dangerous ideas. In the same way we say "I've got to piss like a racehorse" and "It's hot as hell," we'll soon be saying "This is as dangerous and stupid as Greg's thing where he built a system that weighted his keeper loop and said the system worked"

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

I am also trying to figure out how you would remove the cord without removing the device.

Secondly… this is stupid! The backup should always be beneath the device for the same reason your brake hand is beneath the device. As stated above.