Autoblock backup through haul loop for rappel?
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The most-advised rappelling method these days seems to be extending the rappel device through a sling and then tying an autoblock to the belay loop. (see rockandice.com/lates-news/r…) . |
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Is this a joke? I'm instantly suspicious due to all of the trolling recently and how ridiculous the idea is. If it's not, go ahead and try it and you'll see why this is a terrible idea... |
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In the setup I am imagining (and tried on the ground), the autoblock runs from the haul loop around the climber's right waist to the rope (NOT UNDER THE LEGS) |
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On single pitch terrain, just lower. See: |
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Ok. Haul loop is on the back of your harness. Autoblock is a short loop of cord that is twisted around the climbing rope then clipped to your harness...in this case, to the back of your harness. Rappel device is usually attached to your belay loop, which is in the...front of your harness. To descend, you will need to slide the autoblock knot down the rope as you feed rope through the belay device. How do you plan on doing that if it is clipped behind you? |
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Ted asks how I adjust the autoblock as I descend. |
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One other drawback of the extended rappel method I forgot to mention: the extended rappel sling must be a very specific length - it must be both: (a) short enough that you can weight the rappel while you are still on your personal anchor system, to confirm you set up the rappel correctly, and (b) long enough that your autoblock knot cannot reach the belay device. And I'd rather not be fiddling with extra knots in slings just to shorten/lengthen them. |
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go try this and tell us how it works out for you |
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You could also just do a regular, unextended rappel like most climbers do 90% of the time. While extending it is nice in some circumstances, it's usually not necessary. The whole "backup getting sucked into the device" thing is pretty overblown and honestly not something I ever worry about. You'd have to either have a ridiculously long autoblock cord (sounds like yours is if you can clip it behind you and somehow end up with the knot in front of you with enough wraps to actually catch) or not do enough wraps (at which point the knot will slip on its own and was useless anyways). Have you actually rappelled before? With an autoblock? A lot of these things will seem pretty obvious when you actually make your way down but might not appear so if you're just hanging from the ground. I'd recommend clipping into an autobelay at the gym and practice rappelling if they let you, as the efficacy of any of these systems is only obvious when you actually make downward progress. The beauty of the autoblock as a rappel backup is that it's probably the simplest rigging you can possibly do and is pretty tough to screw up. I'd practice approved methods before getting creative with safety systems... |
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In addition to just being awkward, you should also think about the fact that the autoblock will essentially be holding the brake strand perpendicular to the device as opposed to below it where the braking is maximized. It'd be like pull straight out to arrest a fall. |
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On initial consideration this method does seem unable to fail due to flipping upside down. However it seems horribly awkward at best. Prone to getting stuck at worst... Try it under safe conditions and report back. |
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Ted Pinson wrote:Is this a joke? I'm instantly suspicious due to all of the trolling recently and how ridiculous the idea is. If it's not, go ahead and try it and you'll see why this is a terrible idea...LOL, yep |
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With the device extended and autoblock below the device you can go hands free if needed. |
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If it's really long enough that it reaches back around to the front anyway, how is this an improvement over just using a much shorter cord on your leg loop? |
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Ted Pinson wrote:Ok. Rappel device is usually attached to your belay loop, which is in the...front of your harness.Oh fuck that! I always rappel Aussie style face first off my haul loop (even off the Maiden). Alex's ingenious system will work perfect for me. I use my belay glasses and tip my head waaaayyyy back and I can see the setup nicely to double check everything is good to go. |
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Alex Krueger wrote: The main point of extending the rappel (as far as I can tell) is to make sure the autoblock knot cannot reach the rappel device,This is not the main purpose of extending a rappel. First, it is how you pre-rig an inexperienced partner. Second, it is a more comfortable and more stable rappel. Alex Krueger wrote: However, I'm not a big fan of extending the rappel through the sling for several reasons: (1) requires extra gear you need to bring(an extra sling);No extra gear, you need a rap sling anyway, so no extra gear required to extend the rappel. Alex Krueger wrote: Nonetheless, I don't see anyone online suggesting to use the haul loop for the autoblock backup on a rappel. I assume that means it is a stupid idea for some reason I am missing.I think you're onto something here. Have you ever rappelled on an extension before? |
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Where are you seeing that the haul loop is rated? The kind folks at BD suggest not putting your body weight on the haul loop. |
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seanfm wrote:Where are you seeing that the haul loop is rated? The kind folks at BD suggest not putting your body weight on the haul loop. http://blackdiamondequipment.com/en_US/experience-story?cid=qc-lab-full-strength-haul-loopsThe haul loop on the Momentum (and all BD harnesses with a bar-tacked haul loop) is rated to 12 kN. It would be impossible to rig this setup in such a way that the autoblock would engage prior to jamming the rappel device, because the length required to get the autoblock around your waist would be greater than the distance from your belay loop to your rappel device. |
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This post gave me aids. |
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Ted Pinson wrote:You could also just do a regular, unextended rappel like most climbers do 90% of the time. While extending it is nice in some circumstances, it's usually not necessary. The whole "backup getting sucked into the device" thing is pretty overblown and honestly not something I ever worry about. You'd have to either have a ridiculously long autoblock cord (sounds like yours is if you can clip it behind you and somehow end up with the knot in front of you with enough wraps to actually catch) or not do enough wraps (at which point the knot will slip on its own and was useless anyways).I don't agree with this. I have no idea "most climbers" and "90% of the time" come from, but if true, then a lot of people are using a suboptimal method for no good reason. Apparently adequate installations can fail if the leg holding the autoblock is raised and almost all will fail if the climber inverts for some reason. It would be one thing if avoiding these issues required a complicated and time-consuming work-around, but that isn't the case here; girth-hitching a sling is hardly a major faff. I'm not a big fan autoblock backups for every rappel, but if you are going to use them, it makes no sense to choose a method with possibly fatal gotcha's when a simple alternate eliminates them. Additional advantages of the extended device are that is allows for a bit of increased friction while also enabling the rapid installation of a very substantial friction-increasing set-up if needed while in mid-rappel. |