/ Self belay using a Petzl Shunt

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plogan5 on 19 Mar 2014 - host109-154-174-130.range109-154.btcentralplus.com

Thanks to everyone for your helpful comments on the previous query I posted recently;


Taking the advice, I have now got the Petzl Shunt but I am seeking some advice on how to decend after it becomes loaded. I have tried it (under controled conditions) as an acender / auto blocker and it seems great. However, when loaded by body weight it seems to be very diffifuclt to decend under control.

I don't think I'm using it with all the correct bits of kit. Can you help me understand how to use it properly please?

Many thanks again.

ukb shark - on 19 Mar 2014
In reply to plogan5:

I don't think it is possible to abseil using it. You need to transfer to another device.

One of the advantages of self belaying using a gri-gri is that it is good for abseiling too.
Oceanrower - on 19 Mar 2014
In reply to plogan5:
Assuming you've read the instructions, you'll know that you can't.

You need to change to a descender (fig 8, belay plate, gri gri, munter hitch, etc.) and use the shunt as a prussic.

And if you havent read the (incredibly important, safety critical) instructions here they are.
Particularly relevant is section 8.

Post edited at 21:07
petegunn on 20 Mar 2014
In reply to plogan5:

My set up when using my shunt:

Rope doubled and tied off at the top i.e. have two strands.
One strand on the shunt, the other strand left free to abseil back down.
I use a grigri to connect to the abseil.
On the shunt, i have a prussik cord through the small hole to help release it.
Weigh down the rope (the one the shunt is going on) with rucksack/spare rope coils.
I tend to use a (semi) static rope. (The routes i have been trying, the crux is near to the ground, on a dynamic rope i would hit the ground on rope stretch).
Rope protectors if necassary.
Either remove the shunt for abseiling or just hold onto the prussik cord to release the shunt while abseiling back down.
Choss on 20 Mar 2014
In reply to petegunn:

And if youre Concerned about Shunt slippage, just bang in a simple overhand Knot Below you every now and then.
SGD - on 20 Mar 2014
In reply to petegunn:

Exactly the same set up as me.

The only thing I'd add is I clip the abseil strand to me (either free running through a krab or already on the Grigri). The only reason I do this is during my baptism of fire of 'how to use a shunt' I discovered it was sometimes difficult to reach the ab line (this was due to the nature of the route I was on) so I quickly learnt to have the ab line rope clipped to me and then I thought If I already have it in the GriGri then when I'm resting I can pull the slack through the Grigri and essentially back the shunt up.
splat2million on 20 Mar 2014
In reply to petegunn:

My setup is almost the same, except I have a handle ascender backup on the other rope instead of overhand knot backup below the shunt.
If the shunt is loaded, I can put my belay plate on the other rope, then take the weight on to that rope in order to unload the shunt (not normally difficult on the grades I climb - up to VS on this system). To be honest I usually just take the shunt off (and of course the ascender) to abseil down.
Choss on 20 Mar 2014
In reply to plogan5:

To unlock a loaded Shunt even if Free Hanging, Bend your Knee on one leg, Loop of rope or Two Round foot and Straighten leg, shunt will unlock and move up.

By controlling the Friction Round your foot you can move up and down the rope using just the Shunt. Takes a bit of Practice.
Cheese Monkey - on 20 Mar 2014
In reply to plogan5:

Easiest using 2 strands. I tie overhands in the second strand and clip a quickdraw into them as I go. To descend just swap to the second strand and undo the overhands as you go.

If you use one strand then put a prussic above you, stand in it then swap to your abseil device.
kfv - on 20 Mar 2014
In reply to plogan5:

Trango cich is worth a mention here, it can be attached to a loaded rope so you just clip it on above your ascender and connect it your harness via a screwgate quickdraw then you can take the weight on the cinch and remove the ascender. It takes about ten seconds.
hkstu - on 21 Mar 2014
In reply to plogan5:

Be really careful trying to use a shunt for descending. If you manage to release it, you can speed up very rapidly. It's not very controlled and can get rope burns trying to stop yourself. Much better to switch to a descender or, as someone else has suggested, use a gri gri.
Timothy Greenhalgh - on 21 Mar 2014
In reply to plogan5:


Just place your shunt on your leg-loop below your abseil device. Problem solved!

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