Autoblock above or below rappel device?

I use a hollowblock2 and I find it far smoother to have it above my rappel device (gigi) but if I were to let go of the rope, all my weight is pretty much just on the third hand. Is that a safety concern or not really?

Thanks for the help!

Should be below your rappel device. If you’re having trouble then you it sounds like you need to extend your rappel device. 

Below. I find that it works best to use your primary hand as the brake, with the other hand tending the friction hitch to keep it from grabbing. 

Edit: also, wrong forum.

Beau Owen wrote:

Should be below your rappel device. 

it depends on the device. for some, above is the preferred method.

I have heard one horror story from a friend whose father would do so called "adventure races" of which some involved trying to rappel a 100 ft cliff as fast as possible (i.e. like 5 seconds) and his prussic snapped because he was moving so fast when it locked.... But it's not really a concern unless you're doing stupid stuff.

If you want to put your third hand below your rappel device, you MUST extend your rappel device.

Otherwise, the friction hitch will impact and be pushed by the rappel device negating it's ability to actually be a third hand.

I prefer extending my rap device with a prussic underneath as it's easier to "unlock" the prussic after its weighted hard and i feel that it gives me more control if I'm rapping fast.

Make sure you test out your setup before assuming your prussic is the right length and don't assume other people's prussics will be compatible with your method of extending your rappel device and vice versa.

curt86iroc wrote:

it depends on the device. for some, above is the preferred method.

Can you elaborate? 

If the friction hitch is above the device, it must hold the climber's entire weight. If placed below / behind the device, it only needs to hold with whatever force is necessary on the brake strand to "lock" the device, for lack of a better word. Also, if you actually weight a friction hitch above your rappel device, you will need to somehow unweight that hitch in order to free it before you can continue rappelling. With a hitch below the device, you can simply hold the brake strand with one hand and then work the hitch free with your other hand.

I can't imagine a situation where placing the backup above the device is the correct choice.

Jared Chrysostom wrote:

I can't imagine a situation where placing the backup above the device is the correct choice.

ever rap on an 8 or rescue 8? you can't perform the proper tie off if you have a 3rd hand under the device...

https://www.cmcpro.com/tying-off-a-rescue-8/

Fast forward to min 3

Jared Chrysostom wrote:

Can you elaborate? ...

I can't imagine a situation where placing the backup above the device is the correct choice.

If you are planning a knot pass, the smoothest method is to place the friction hitch above your rappell device.  Use a cordalette for the friction hitch and attach it to yourself with an MMO. 

When you reach the knot to be passed, fully weight the friction hitch.  Tie into a catastrophe knot a few feet below the knot to be passed.  Remove and replace your device below the knot to be passed, ideally extended with a friction hitch below.  Then lower out the MMO and retrieve your cordalette.

I can't imagine a situation where placing the backup above the device is the correct choice.

For passing a knot on rappel, the Kirkpatrick How-to-rappel book suggests using a VT hitch above the device. 

Erik G wrote:

If you want to put your third hand below your rappel device, you MUST extend your rappel device.

Not true. Most people put the autoblock on their leg loop and don't extend the rappel device.

FrankPS wrote:

Not true. Most people put the autoblock on their leg loop and don't extend the rappel device.

Best practice is to extend your belay device and place a third hand attached to your belay loop.  

Many climbers use the above mentioned technique to save time.  However, a third hand on your leg loop can easily be defeated by the device if you become unresponsive and invert.  Hence the best practice of extending.

FrankPS wrote:

Not true. Most people put the autoblock on their leg loop and don't extend the rappel device.

True. But if you want to do that correctly, you need a well sized prussic loop, because as mentioned above if it's too long it can bump on the atc/device & then it may not grip. I've been doing that for a long time. I've switched partly because of that (less flexible), but also because it somewhat tends to throw you off balance/to the side a little so you end up somewhat fighting with the core to say more upright.

IMO the above video is the best overall method as a default, go-to option for most cases. Extend the rappel, put the third hand below. Having the hitch closer to you as opposed to above makes it easier to slide (as opposed to extended arms above). Having the rappel extended gives you more room to maneuver, as opposed to having the device straight into your belay loop. The size of the prussic loop matters less too, so it's easier to adapt if you use different ropes/diameters, you can keep the loop long enough to do more wraps if needed (single-strand rappel, say, smaller diameters etc.). If you do fewer loops, it will reach higher but it doesn't matter because of the extended rappel.

The added bonus to extending the rappel and having the end of the sling/leash be your locking carabiner to secure yourself to the anchor makes it overall smoother to first weight test your rappel setup. You just need to pull on your leash, take in on the belay device, weight it. Everything is more in line this way, as opposed to the belay device directly on the belay loop with some separate sling to leash.

Philip Magistro wrote:

Best practice is to extend your belay device and place a third hand attached to your belay loop.  

Many climbers use the above mentioned technique to save time.  However, a third hand on your leg loop can easily be defeated by the device if you become unresponsive and invert.  Hence the best practice of extending.

I think Frank's issue was more with the MUST in caplocks. It's not true that you MUST. You can just use a shorter prussic loop/more wrap and it'll still work fine.

FrankPS wrote:

Not true. Most people put the autoblock on their leg loop and don't extend the rappel device.

"Most" is a pretty strong word. 

I sometimes go with the device on the belay loop, sometimes with an autoblock on the leg loop and sometimes without an autoblock at all. For short, single pitch rappels with little overhead hazard, it can be an accepted risk for the sake of speed.

For multi-pitch rappels, I would say that most people extend the device and use an autoblock from the belay loop... as they should, IMO.

Bob Harrington wrote:

For passing a knot on rappel, the Kirkpatrick How-to-rappel book suggests using a VT hitch above the device. 

Yes, and the VT is connected directly to the rap device, which means it doesn't have to take the full climber's weight.  I think this method is worth more study---it might actually be the best way to back up a rappel, since it doesn't require an extension.

Tom Salerno wrote:

I use a hollowblock2 and I find it far smoother to have it above my rappel device (gigi) but if I were to let go of the rope, all my weight is pretty much just on the third hand. Is that a safety concern or not really?

Check the strength rating of your hollowblock and ask yourself again the question of whether it's safe to hang on it.

FrankPS wrote:

Not true. Most people put the autoblock on their leg loop and don't extend the rappel device.

I see less and less of this, as most people wise up.

If you end up having to ascend the rope it's probably easier if it's above the device (this can happen if you pass a rap station or an anchor site on an unknown descent).  But generally it's best practice to install below.  Then again best practice is over-rated.

JaredG wrote:

If you end up having to ascend the rope it's probably easier if it's above the device...

It's true that to ascend you will need to place a friction hitch above the device.  I think the transition from rappel to ascension, though, is most easily done with an extended device and friction hitch below:  Simply weight the friction hitch and tie into a catastrophe knot below.  Hitch your 48" or cordalette onto the rope above the device and use it as a foot loop to step up.  Clip the device to your belay loop using a locker on the plaquette loop.  Done.  The extended rappel setup can remain in place for the transition back to descending.

Then again best practice is over-rated.

Care to explain?  'Cause I don't really agree with you on that.

Alright, thanks for all the replies. It sounds like below is generally the way to go.