Releasable rigging using a Petzl Stop

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Re: Releasable rigging using a Petzl Stop

Postby Extremeophile » May 2, 2013 10:07 am

jharman2 wrote:Thanks for the link NZ. I'm going to try this with a belay. Looks pretty sketchy and would certainly be a situation where you'd want a shunt or other method of stopping.

I seem to recall reading about this in ACT and its use being discouraged. I would think downclimbing the rope is a safer alternative.
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Re: Releasable rigging using a Petzl Stop

Postby chh » May 6, 2013 1:41 pm

The picture from vertical does work, though less reliably if your bobbins are really worn (not enough bend introduced) you can also stick the rope in between the top bobbin and the upper pin, as it is a smaller space than in between the bobbins if they are worn, and there is more distance for leverage, but you have to be vigilant about torquing the body if you take your weight off. FWIW, I put the bobbin on my short cowstail, or even clip my short cowstail to my half round(I use a locker on the short cowstail termination) and then clip the bobbin into that to keep it close. This gives enough space to run a VT clipped to the half round below the device as a safety. I would never descend a free hanging rope (especially a weighted one) on just a VT, though I have descended rope with just the VT when there was opportunity for some physical downclimbing.

For gearheads who want to buy a piece of gear that would potentially be of use in a loaded rope scenario, check out the Singing Tree Rope Wrench. I've used one at work, and the latest version is midline attachable, which wasn't the case with previous incarnations. This tool works very similarly in concept to using a bobbin and VT to descend a weighted rope.
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Re: Releasable rigging using a Petzl Stop

Postby NZcaver » May 6, 2013 4:15 pm

chh wrote:For gearheads who want to buy a piece of gear that would potentially be of use in a loaded rope scenario, check out the Singing Tree Rope Wrench.

Haven't tried that one. The Petzl ZigZag (basically a mechanical VT) would have been another option, but it's just been recalled for safety issues. :sad:
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Re: Releasable rigging using a Petzl Stop

Postby chh » May 6, 2013 7:33 pm

NZcaver wrote:
chh wrote:For gearheads who want to buy a piece of gear that would potentially be of use in a loaded rope scenario, check out the Singing Tree Rope Wrench.

Haven't tried that one. The Petzl ZigZag (basically a mechanical VT) would have been another option, but it's just been recalled for safety issues. :sad:

I heard that, but never did much reading about the product. I'm still unsure if was intended for SRT as well as DRT rope work. Too spendy for this guy in any case. On an interesting note, i think the first prototype for the Rope Wrench was just a hickory tool handle with some holes drilled in it. I like the simpler design of the rope wrench anyway. Another reason I was never really all that interested in the Unicender. Too big, too complicated, and too spendy.
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Re: Releasable rigging using a Petzl Stop

Postby Auzric » May 8, 2013 4:34 am

Something to add...use a carabiner thru the slings and around the rope at the same location as the pulley, to back up the pulley should the pulley fail.
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Re: Releasable rigging using a Petzl Stop

Postby OpenTrackRacer » May 14, 2013 2:59 pm

Good idea! I'm not worried with the Fixe pulleys but this already crossed my mind for the Rescue.

Auzric wrote:Something to add...use a carabiner thru the slings and around the rope at the same location as the pulley, to back up the pulley should the pulley fail.
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Re: Releasable rigging using a Petzl Stop

Postby NZcaver » May 14, 2013 3:52 pm

Auzric wrote:Something to add...use a carabiner thru the slings and around the rope at the same location as the pulley, to back up the pulley should the pulley fail.

I used to do that... until I watched rated pulleys being destruction tested and realized the force required to break one would also break an alloy carabiner. That level of redundancy seems unnecessary. Maybe if you were using a micro with a plastic sheave.
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Re: Releasable rigging using a Petzl Stop

Postby Caver John » May 19, 2013 3:05 pm

A Munter mule is sufficient
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