placing an auto block

To put it simply ... If you are going to clip th autoblock to the leg loop ...

theres is no good reason not to clip the inside leg loop

Theres no cost, extra time or special gear required

While not all quick release buckles may come undone with a biner clipped right on top of em ... Theres no reason to take the chance

Can anyone think of a good reason not to do this ...

Rather than this ...



Except for a sense of "intrawebz pride"

As to extending the rappel ... One point which folks often dont do properly is to not extend the device above where you can easily reach above it

If you need to reascend the rope or pass a knot ... Youll need to be able to set a prusik above the device ... No higher than chest/shoulder height

;)

Hi,
clipping it to the inside leg loop is fine a most of the time. However if the leg loops are slack and the prusik cord long, then when not in use it will slide down and possibly form a trip hazard. This isn't a problem on simple, chain-to-chain raps, but can be if you are scrambling or walking between stations. Of course this could solved by girth hitching the prusik to the inside leg loop and using the carabiner to clip the other end of the prusik to a gear loop when not it use.

Tom Sherman wrote: Wtf are you talking about? Prone to failure, my Prussik is gonna fail, because its on my leg? No I clicked this thread because I knew it'd be a shitshow. Its everyone opinion, and this one's a big conflict. Greg D said it best, be aware, sounds like you are. I use a runner to extend and Prussik on leg loop.

I'm talking about a sensible safety that isn't going to fail when you most need it. You are ignoring the issues.

Greg D wrote: I couldn't say for sure why you can't tell. But most climbers can.

How is that? How do you normally ensure that your torso remains upright while you are unconscious?

Hope I didn't sound like too much of a Dick last night, but was drinking beers after my hockey game when decided to get on MP.

Yes leg loop, but I am going to slightly recant. I thought you all were saying, jam Prussik in ATC, blah blah blah. But it looks like bearbreeder is trying to imply that his carbiner is gonna ratchet open the leg loop. That very much looks like it could be a problem. Out of sheer coincidence, I use an oval locker here. From now on though, I will be aware if for some reason I am getting my gear swapped around and would be using anything other than my typ rap locker. That oval lives on my harness w Prussik and runner, just for raps.

Patto you are talking of an extremely rare scenario, and while your point has potential for validity, IMO, it's a one or the other argument, i.e. placing it on loop, has its drawbacks equally.

Thousands and thousands, most likely millions, of rappels have been done safely worldwide during the hundred years since Dulfer invented the first technique, so the fact that there aren't a lot of accidents with backed-up rappels doesn't mean much, and does not begin to speak to any claims about one method being better than another.

I think Patto has a point: if you are going to back up a rappel, it seems a matter of common sense to choose the method with the fewest known failure modes, especially since in rappelling you typically don't get a second chance if you screw up. Yes, the failure modes may be very infrequent and improbable, but if there are equivalent techniques that don't have those failure modes and don't add new ones of their own, why, as a matter of logic, use the ones that do?

The leg loop prussik has two known failure modes. I don't know of any analogous failure modes specific to the extended method. I do know of one very serious accident due to mode #2 below.

1. If the leg loop is adjustable, the buckle can be opened unless the prussik is placed inside as illustrated in bearbreeder's photos.

2. High-stepping with the leg with the prussik attached can raise the prussik several inches. I'm not sure you can set up the system, even with a very short prussik, to avoid a prussik-device collision in this case, but I think many of the set-ups actually in use, especially if the climber hasn't specifically tested this situation while tying the prussik, will release under these conditions. High-stepping this way while rappelling is not something folks usually do. It might happen while cleaning on rappel. If you use a prussik on a leg loop, vigilance about this is required!

I think most people turn slightly sideways when rappelling, typically toward their brake hand. This means the brake hand side leg will usually be lower than the other leg, and if the prussik is going on a leg loop it seems prudent to put it on the brake hand side leg to keep it lower.

By the way, a failure mode common to all methods is too loose a prussik. I see people rapping with very loose knots and wonder whether the knot would grab if it was required to.

If you invert on an abseil or otherwise go limp you can easily end up with your leg loop auto block fouling your belay device.

Personally I don't backup most of my rappels. Even in the cold, wet environment of canyons. I am confident that I have the control of my brake rope hardwired. I can happily switch hands, and fend off walls and negotiate logs and other difficulties. I can go hands free with leg wraps.

If I am using a backup I extend it with a good prusik knot and test it properly. I have no use for a backup unless I have 100% faith in it.

rgold wrote:By the way, a failure mode common to all methods is too loose a prussik. I see people rapping with very loose knots and wonder whether the knot would grab if it was required to.

I too see that often.

I'm all for extending your rappel device (I always extend my rappel with a short runner, even when running my autoblock off the leg loop).

But it seems that a lot of the people who advocate extending the rappel and running the autoblock off the belay loop overlook one very real danger with this method: the possibility that the rappel device will end up out of reach once the rope is weighted and you're on rappel.

There are plenty of very real scenarios where this could be a major issue (if you get something jammed in your device, if you reach the end of the rope and find you're still 20 feet off the ground, if you're on a multi-pitch rappel and you accidentally pass the next anchor/stance and need to ascend a few feet back up to it, etc.). In any case, if your rappel device is out of reach, you're hosed. This isn't some trivial issue either; unless you can climb the rock itself (god help you if you're on an overhang or on a slickrock face) or your partner is well-practiced in technical rope rescue techniques, then you could very well be dead in less than a half hour. Research harness hang syndrome if you don't believe me.

Now, I'm not saying you shouldn't extend your rappel device (like I said, I do so on pretty much every rappel). BUT for everyone preaching about how extending the device is a no-brainer (and especially those insinuating or even outright declaring that there are no additional safety drawbacks with this technique), you do a potentially fatal disservice to those you advise by not mentioning the danger with extending the device too far out of reach.

Huh? I don't have a non brake hand when rapping.

There is also no way I want to be rapping with devices that normally need you other hand to release it. This means you have ZERO hands to control the environment around you while descending.

Also if there is a rock falling on you while you are rapping then you should be aware of the issue and it is probably your fault anyway.

patto wrote: Also if there is a rock falling on you while you are rapping then you should be aware of the issue and it is probably your fault anyway.

It's his fault so he deserves to slide down the rope and die? Not all rockfall can be foreseen or predicted.

There are many ways to skin a cat, and an autoblock is a good tool in the safety arsenal. I'll never understand why you would argue against it.

Ever seen how the prusik minding pulley works? When you use a leg loop for your backup, there is often not enough room between your rappel device and the prusik, so your belay device becomes the minding pulley. I know of one fatality that was due to insufficient distance between the rappel device and the autoblock.

Besides, the leg loop is not rated to hold your body weight. There was a long discussion back in a day on RC.com and the BD technical engineer chimed in and told everybody to use the belay loop to back up the rappel (with extended device of course), because that's the strongest part of your harness.

Friends don't let friends backup on leg loops. Just because you've been practicing safe-ish technique for years and not gotten into any trouble, doesn't mean you shouldn't be teaching beginners the SAFEST PRACTICES out there. Remember, it's the Beginners Forum.

Simple solution if you're adamant against extension: clip the biner to the lower reinforced tie-in point (no risk of leg loop loosening) and use the proper length cord to ensure the autoblock fully engages and doesn't interfere with your atc. Most sewn slings are too long for this, so just make your own out of cord. You can also get my favorite sewn loop, the 13.5“ sterling hollow block.

doligo wrote:Besides, the leg loop is not rated to hold your body weight.

It's not holding your body weight, it's only holding the force required to keep the rope in the braked position. This is a mere fraction of body weight and is well within the limits of your leg loops. Do some research on the actual forces exerted on the autoblock and the leg loop during a rappel and you'll quickly see that this is a trivial non-issue.

doligo wrote:Friends don't let friends backup on leg loops. Just because you've been practicing safe-ish technique for years and not gotten into any trouble, doesn't mean you shouldn't teach beginners the SAFEST PRACTICES out there. Remember, it's the Beginners Forum.

That's great and all, but your holier-than-thou assertion that using the belay loop is the "SAFEST PRACTICE" is, at worst, flawed and innacurate, and at best, severely limited and clouded by bias. I do sincerely appreciate your concern for the safety of beginning climbers, and it's fine to have your own preferences for your personal go-to technique, but I do hope you realize that using your leg loop isn't just some cockamamie "safe-ish" technique, it's an established standard. The fact that you don't recognize it as such makes me question your knowledgeability on this matter. This is the method recommended by Freedom of the Hills, as well as The Mountaineering Handbook (note that in this latter case, Connally recommends extending the rappel device with a 1-foot sling to eliminate the primary downside to this technique: the possibility of the autoblock catching in the device). This is also the method recommended by EVERY guide I've ever met or otherwise have seen using a rappel backup, everyone from local SPIs to EXUM guides; and it's the technique that saved my life when a car-sized chunk of the cliff decided to come loose (with me still attached) as I was approaching the edge of a rappel.

The primary reason that all these seasoned veterans cite for preferring this technique versus using the belay loop? If you run the prusik off the belay loop, then it's tricky to get the right length of extension for the device (especially for beginners who don't have experience). Extend it too far, and it'll be out of reach when you most need to get at it. Extend it not far enough, and you're faced with the same problem that you had with an un-extended device and a prusik rigged to the leg loop: the knot could catch in the device and pry it open in the event of a fall.

I personally am a big fan of running the autoblock off the leg loop AND ALSO extending the device with a short runner (use the inside of the leg loop if you have plastic buckles or are concerned about prying your buckles open). It's the best of both worlds. You only need a little bit of extension to eliminate the possibility of the knot catching in the device, so by using a very short runner you can get your backup safely out of harm's way while still keeping the device well within reach.

I'm not saying this is "the best" technique or "the only" technique, just that it is one of multiple standard techniques that, when used correctly, is very safe. You act like extending the rappel and attaching the prusik to your belay loop is the only technique that should be taught to beginners because it's somehow inherently safe or fool-proof. It's not! Just like with the leg loop technique, it's only safe when used properly. As I have already mentioned extensively, extending the device out of reach is a very real danger with this technique. This is not something that most beginners would intuitively think of, so just blindly teaching this technique to beginners without mentioning this danger could be just as deadly as teaching beginners the leg loop technique without explaining the dangers of the knot getting caught in the device.

So basically what I'm saying is that both techniques are widely used and are more-or-less standards; both techniques have potential dangers that need to be explained when teaching these methods to beginners; and both techniques, when used properly, are equally safe and capable of accomplishing the task for which they were designed. So let's get off our high horse and stop acting like one technique is objectively and significantly better than the other when they both have their pros and cons.

Rob Wild wrote:In any case, if your rappel device is out of reach, you're hosed.

Nonsense.

Rob Wild wrote:...for everyone preaching about how extending the device is a no-brainer (and especially those insinuating or even outright declaring that there are no additional safety drawbacks with this technique), you do a potentially fatal disservice to those you advise by not mentioning the danger with extending the device too far out of reach.

Well, it shouldn't be out of reach, I would have though even a beginner could figure that out. Do people practice this the first time in a safe environment, or do they just go up and dive off a full-length overhanging rappel without even trying out the system? It is hard to know how many obvious things need to be said before one avoids providing a "fatal disservice."

Moreover, unlike the possibility of the leg-loop mounted prussik simply releasing if the leg is raised, an out-of-reach device is not a "failure mode" and so belongs to a much less serious category of problems. Of course you shouldn't rig that way to begin with, but if you do, and if you know how to escape the list of "potentially fatal" scenarios with your device in reach, then frankly, there is no problem just because it is out of reach.

rgold wrote: Well, it shouldn't be out of reach, I would have though even a beginner could figure that out.

I would hope that the average person would indeed be able to figure that out on their own, but unfortunately I wouldn't count on it. On second thought, maybe it's best we don't mention this....that way the Darwin Award candidates can be allowed to show their true colors. :)

rgold wrote:Do people practice this the first time in a safe environment, or do they just go up and dive off a full-length overhanging rappel without even trying out the system?

Of course they do (or at least, I would hope they do), but who's to say you can't learn how to do something incorrectly, practice it that way for months, and not ever know that you're doing it wrong until an unfortunate accident presents you with a problem you didn't foresee? Not saying it happens every day, or anything, but people have died this way before, so it's not purely hypothetical.

rgold wrote:It is hard to know how many obvious things need to be said before one avoids providing a "fatal disservice."

Very true. There's only so much you can teach. At a certain point you have to trust that people will have the common sense to make reasonably competent decisions in regards to the safety systems responsible for their well-being.

rgold wrote:Moreover, unlike the possibility of the leg-loop mounted prussik simply releasing if the leg is raised, an out-of-reach device is not a "failure mode" and so belongs to a much less serious category of problems. Of course you shouldn't rig that way to begin with, but if you do, and if you know how to escape the list of "potentially fatal" scenarios with your device in reach, then frankly, there is no problem just because it is out of reach.

Also agreed, although in the context of teaching things to beginners, it is unlikely that a beginner would know how to escape a rappel with their device out of reach. Still, this is only a problem in the fairly unlikely event that the rappeller gets stranded mid-rappel.

I'm not trying to argue that the belay loop method is unsafe, just trying to play devil's advocate a little and remind people that there are caveats with both methods.

I guess I kind of got too busy rambling in my second post to actually explicitly say this, so let me make my opinion very clear: I do believe that extending the rappel device and backing up to the belay loop is safer than backing up to the leg loop without extending the device (even though the un-extended leg loop method is a standard taught by many guides and in many texts, including FotH). BUT, I would argue that backing up to the leg loop AND extending the device (using a much shorter runner than you would need if you attached the autoblock to the belay loop instead) is safer than both of 'em. This last method is the one taught in The Mountaineering Handbook and by most of the guides I have known, and the system that I use.

Sorry, I should know better than to try to coherently organize my thoughts late at night after working 11 hours! :)

And let's face it, yer prolly gonna die either way, so it doesn't really matter.

FrankPS wrote: It's his fault so he deserves to slide down the rope and die?

How did you come to that conclusion.

FrankPS wrote: There are many ways to skin a cat, and an autoblock is a good tool in the safety arsenal. I'll never understand why you would argue against it.

I am not arguing against it. I've chosen to use it on a number of occasions.

Rob Wild, have you ever had your rappel device fail? I have. I mis-threaded it. Thankfully, I had an autoblock off my belay loop, so I was hanging off my prusik only. Yes, my whole body was hanging off a single prusik knot. I would've hated to have been hanging off my leg loop. That's what backups are for - to backup catastrophic failures, not for assisting your braking hand. There is a great device for assisting - it's called Gri Gri.

Rob Wild wrote:This is also the method recommended by EVERY guide I've ever met or otherwise have seen using a rappel backup, everyone from local SPIs to EXUM guides;

Not true.

Besides, out-reach rappel device is not an issue at all. You really don't need to be touching the device any way past initial few feet when there is less rope above you, unless you want to burn your hands. You can simply control your descent with your prusik. Do people really need to mess around with their rappel devices during descents? I can only think of a few situations like passing a knot (advanced application, where you really want to have your prusik off the belay loop) or hair/clothes getting stuck in the device (the problem is eliminated by extending your rappel device).

Not everything written is absolute and final truth. FOTH has been first published in 1960, it gets revised but I doubt it gets the most thorough revision. The latest edition is already 5 years old. Just look at the CPR standards - it changes like every year.

doligo wrote:Rob Wild, have you ever had your rappel device fail? I have. I mis-threaded it. Thankfully, I had an autoblock off my belay loop, so I was hanging off my prusik only. Yes, my whole body was hanging off a single prusik knot. I would've hated to have been hanging off my leg loop. That's what backups are for - to backup catastrophic failures, not for assisting your braking hand. There is a great device for assisting - it's called Gri Gri.

Actually, that is PRECISELY what back-up knots (in the context of autoblocks for rappelling, anyway) are for. They are there to take over for the brake hand should it ever leave the rope (for instance, if you're stung by a bee, knocked unconscious by rockfall, etc., OR if you need to intentionally halt the rappel and let go of the brake strand to remove a stuck rope, etc.). They are NOT intended to hold the full weight of the rappel. Doesn't mean they can't (obviously!), but that's not their intended purpose.

Failing to properly thread your rappel device is another issue entirely. I suppose having the prusik on the belay loop would be good in such an extremely rare case as this, but really, that's what "pre-flight" safety checks are for, not 5mm prusik cords. Double-checking your rap setup before you commit to the rappel should ALWAYS be S.O.P. It would be impractical to have backups for every little (or big, as the case may be) mistake you could possibly make while setting up your systems; that's why you and your partner double-check everything. If you're by yourself, you triple-check everything, ESPECIALLY your attachment to the rope via the rappel device and the attachment of the rope to the anchor. You can't replace thoroughness, attention to detail, and obsessive double-checking with a 5mm prusik attached to your belay loop and call it good. That said, I'm glad you had it rigged the way you did and are here to tell about it! :)

It's not that extremely rare. Check out some back issues of the ANAM.