Locking off Figure 8 descenders

[John195123]

Hi all, I am new to this site, so I don´t know if this has been posted recently or not, but here goes... I usually use a rack or an ATC for descending, but I´ve been playing around with a figure 8 device and, besides not getting much friction on a single rope, would like to know how to lock one of those off, such as when needing to pass a knot or a rebelay. Any proven methods? Or just hold on tight and work the rebelay with the other hand? Thanks, John

[ratagonia]

Hard to answer with words, so I took some pictures and made a quick tech tip. Find it here:

http://tinyurl.com/8dpa8

Should be noted that the solidity of the lock varies with the properties of the rope, and requires that the tension be continuous. If you are standing on a small ledge or footholds, you MUST maintain tension.

And it only works with certain figure 8s, like the Petzl Huit or the SMC flat-face Figure 8.

Tom

[skianddive]

Tom,

First, this is in regards to your pictures (great clarity, btw).

I was taught that when rappelling on a Figure 8 (by the ACA), the rope should go over the neck of the Figure 8, not under it. Why? I was told that this is to prevent girth-hitching the rope on the Figure 8. If the Figure 8 is rigged as you have it pictured, couldn't the underneath part of the rope be caught on a rock/branch/ledge/branch while descending?

If so, the rope would be forced upwards and forward towards the anchor creating an almost unlockable girth hitch. If the rope is put on top of the Figure 8, however, the rope is at least protected by the rappeller's body and rope cutting in front.

Maybe this is a minor point, but I thought I should bring it up since I usually do a visual check of rappellers and tell them about this discrepancy while they are setting up their rappels. I'd just like to know if I am correct.

Second, isn't this quick method of "locking off" a Figure 8 an advantage of it over an ATC-XP?

Thanks.

[rcwild]

ACA teaches several ways to rig a figure eight. Lee is referring to what we call "standard mode".

1. Clip carabiner to your harness, then clip big hole of figure eight onto carabiner.

2. Pass bight of rope through big hole of figure eight from the bottom up. Pass bight over "neck" (small end) of figure eight.

3. Remove figure eight from carabiner, flip end-for-end, clip carabiner into small hole of figure eight. Lock carabiner.

Reverse these steps to remove the rope at the bottom of the rappel.

Two advantages: (1) Greatly reduces possibility of losing gear. Figure eight is either on carabiner or on rope at all times; not loose in hand. (2) Rope passes over top of neck, instead of the bottom, greatly reducing possibility of girth hitching.

[rcwild]

Hi all, I am new to this site, so I don´t know if this has been posted recently or not, but here goes... I usually use a rack or an ATC for descending, but I´ve been playing around with a figure 8 device and, besides not getting much friction on a single rope, would like to know how to lock one of those off, such as when needing to pass a knot or a rebelay. Any proven methods? Or just hold on tight and work the rebelay with the other hand? Thanks, John

Hi John. Welcome to the ACA's Canyon Forums.

One big advantage to using a figure eight is the ability to rig it many different ways to provide the correct amount of friction. Rig it one way for double strands of thick rope, another way for single strand of thin rope, etc. If you are not getting enough friction, you simply need to learn other ways to rig it.

In ACA basic courses, we teach several ways to rig rappelling devices, but only one way to lock off -- the leg wrap -- because some lock off methods work with some rigging methods, but not with others. We teach other lock off methods in our advanced courses.

The lock off method in Tom's photos only works when eight is rigged in "standard mode". It won't work when eight is rigged in "canyon mode" (aka "rapid mode"). Petzl Pirana is always rigged in canyon mode, so another lock off method is required. Easy with the Pirana's "hooks". Locking off a tube device requires another method.

Nice thing about leg wrap is that it will work with any device, regardless of how it is rigged.

1. Stop. Hold hand in brake position on hip/butt.

2. Reach between legs with non-brake hand and pull rope forward between legs. Pass the rope outward, back to brake position on hip/butt. Repeat until you have 3 or 4 wraps of rope around your upper thigh.

3. After final wrap, clip rope into carabiner on gear loop on your brake hand side to keep rope from unwrapping.

[ratagonia]

Tom,

First, this is in regards to your pictures (great clarity, btw).

I was taught that when rappelling on a Figure 8 (by the ACA), the rope should go over the neck of the Figure 8, not under it. Why? I was told that this is to prevent girth-hitching the rope on the Figure 8. If the Figure 8 is rigged as you have it pictured, couldn't the underneath part of the rope be caught on a rock/branch/ledge/branch while descending?


Right you are. I showed it the way it is for clarity. Turned the other way, the position of the rope would not be so clear.



If so, the rope would be forced upwards and forward towards the anchor creating an almost unlockable girth hitch. If the rope is put on top of the Figure 8, however, the rope is at least protected by the rappeller's body and rope cutting in front.

Maybe this is a minor point, but I thought I should bring it up since I usually do a visual check of rappellers and tell them about this discrepancy while they are setting up their rappels. I'd just like to know if I am correct.

Second, isn't this quick method of "locking off" a Figure 8 an advantage of it over an ATC-XP?

Thanks.

The (correct style of) Figure 8 has several advantages over an ATC-XP. Whatever device one uses, locking off in mid-rappel is a good skill to practice and get dialed.

Tom

[John195123]

Thank you all very much for your assistance with this. I think I need to play around with the different techniques, and I'm sure instruction in the matter wouldn't hurt ;) Maybe when I get back to the US. Thanks again, John

[crankin]

I finally got around to looking at Tom's Tech pics.

In standard mode, when using that technique, I have always, after effecting that shown in the photo, taken a bight of the free end through the carabiner attaching the Figure 8 to the harness and repeating the first step.

I have tried out suspending myself after just one wrap between the Figure 8 and rope with no apparent fatality, but I just wanted clarification as far as the ACA Standards are concerned. Is one sufficient?

[rcwild]

... but I just wanted clarification as far as the ACA Standards are concerned. Is one sufficient?

Did it hold with one? If yes, one is sufficient. If not, one is not sufficient. :D

[rambler-joe]

Nice thing about leg wrap is that it will work with any device, regardless of how it is rigged.

Glad to see someone else likes the leg brake. We also teach locking off by pulling the rope right under the butt and tying a bight into the carabiner. a little more awkward than the leg brake but it too works with any device.
rambler-joe.

[coolcat83]

Second, isn't this quick method of "locking off" a Figure 8 an advantage of it over an ATC-XP?

I find locking off a atc with a mule knot very fast, i have been a rock climbers for years so maybe i'm just used to it, that and rap backups.