How to do a changeover on a figure 8 descender?

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How to do a changeover on a figure 8 descender?

Postby RoanHighlandsMan » Apr 8, 2014 7:18 pm

I don't know how you would lock off the rope. Everything else is pretty easy to figure out, I imagine. Would the method change much if you were using a frog or ropewalker instead of knots?
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Re: How to do a changeover on a figure 8 descender?

Postby GroundquestMSA » Apr 8, 2014 9:00 pm

See this topic. A lot of people hate the figure 8, as you will see. Despite all of their complaints, it remains a perfectly adequate descender in the right settings.

I have practiced changeovers with 8s and ATCs many times. While it is probably considered unacceptable, I have had great success locking off by wrapping the rope around my leg a few times. A bight can then be clipped to the harness. I don't weigh anything, so that probably increases the success/comfort of this technique. It's worth practicing in a controlled setting, if only as an emergency skill.
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Re: How to do a changeover on a figure 8 descender?

Postby Stridergdm » Apr 9, 2014 5:51 am

Agreed they're acceptable i the right situation.

Generally I've seen what many call a "rescue-8" (i.e. an 8 with horns) used instead of a regular 8 and basically a knot is tied around the horns.

A little googling brings up: this diagram..
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Re: How to do a changeover on a figure 8 descender?

Postby PeterFJohnson » Apr 9, 2014 11:40 am

A Mule Hitch is another option. It can be used to lock off most belay/rappel devices including an 8 and is described in Mountaineering: Freedom of the Hills (as opposed to just being something I found on the internet).

EDIT: After looking at the page I linked to I noticed that they don't show a back up overhand knot on every device. It was my understanding that you always put an overhand back up above the mule hitch(as they do on the munter hitch in that link) in order to make it safe to go hands free. This is also how Freedom of the Hills describes the knot - at least for an ATC.
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Re: How to do a changeover on a figure 8 descender?

Postby Anonymous_Coward » Apr 9, 2014 4:47 pm

Yeah, the mule knot shouldn't really go hands-free until you add the overhand. I recently saw it a different way: safetied by clipping the mule loop to the rigging (harness) with a carabiner. This would work too, but doesn't seem much easier than using an overhand and it also commits another piece of gear.

Using the mule/overhand, you get a soft lock and hard lock option just like using a rack or bobbin. This is how I lock off when using a tube or eight style device.
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Re: How to do a changeover on a figure 8 descender?

Postby GroundquestMSA » Apr 9, 2014 5:02 pm

Be careful. The sketch below shows how I intuitively started locking off my rescue 8 when I first bought it. It worked fine, though I was never quite sure what to do with the tail; let it hang, poke a bight through the carabiner, overhand knot above, etc. I mention this because while there's plenty of friction available for a secure lock, it can unwrap itself. I was goofing about in a tree just trying to adjust my frog system when I locked off like this and fiddled with my gear. The thing unwrapped and dropped me 15' onto my rump, in the gravel, which hurt, a lot.
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Re: How to do a changeover on a figure 8 descender?

Postby Shane S » Apr 9, 2014 5:24 pm

Not all the fig 8's have a tie off bar. If not a complete overhand knot should suffice. Make sure it's a complete overhand and not a half hitch "often confused". Always remember when doing a change over never remove the top ascender and commit to that rappel device until you have proved the device by dropping an inch or so.
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Re: How to do a changeover on a figure 8 descender?

Postby Anonymous_Coward » Apr 10, 2014 10:22 am

Shane S wrote:Not all the fig 8's have a tie off bar. If not a complete overhand knot should suffice. Make sure it's a complete overhand and not a half hitch "often confused".


I disagree with the advice above. It is the exact opposite of what I was recommending.

If you tie an overhand, when you weight the eight for the rappel test the knot can seize and become impossible to untie. (ask me how I know this :big grin: ) It is the only thing holding your weight, besides a tiny bit of friction on the eight. It is often necessary to go onto ascenders to release the overhand, and then you have to start over. Even if you were able to untie the incredibly weighted knot, if you use two hands to do it, then you end up releasing the rappel device with no hand on the brake. This is generally not a good idea.

If you instead tie a half-hitch on a bight just above the rappel device, that is called a mule knot, recommended above by P. Fitzgerald Johnson. The mule will butt up against the rappel device and stop you from moving downwards. (soft-lock)

Once you have the mule tied, THEN tie it off with an overhand. This gives you a hard and soft lock. To unlock, untie the overhand (hard lock) and get a grip on the rope below the rappel device. The real beauty of the mule knot IMO is that when you pull the mule loop through, it releases the soft lock, AND you end up with the brake end of the rope in your brake hand ready to rappel.
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Re: How to do a changeover on a figure 8 descender?

Postby Shane S » Apr 10, 2014 6:55 pm

I really didn't specify enough information here just specified what knot I use. I have used a figure 8 on small drops many times and have never had problems un-tying. Keep in mind that it is always a good idea to attach a QAS before you untie. Leave enough slack so that you don't weight the QAS if you plan on rappelling.
I usually use an overhand know. But I usually take the non working end of the rope and cross the working rope in a manner to pull down. After this I will take a wrap around the mid part of the figure 8. Then I will loop back through it and go above it and tie an overhand. By now I have enough friction to not weight the knot.
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