Autoblock backup through haul loop for rappel?

Alex Krueger wrote:Thanks for the response, 20kn What's your preferred method for attaching an autoblock when you want to connect the ATC directly to the belay loop?

Leg loop.

David Coley wrote: This is one difference I have seen between US and UK practice. In the US the recommendation seems to be to extend about 60cm, but I have seen a lot longer. UK books seem to go for 30cm or less.

I'm not sure why so many Americans do that. I extend my rappels and tie my prussik cord to my belay loop, and my rappel device is still not at my face (I'm also not very tall). You only need to extend it far enough that your third hand does not reach your rappel device. People have pointed out that the OP must have a long third hand cord if it can reach from his haul loop to his side after everything is tied in, and I would say you have too long of a third hand if you need to extend your rappel a full 60cm. Keeping your extension as short as possible while still keeping your device out of reach of your third hand mitigates most of the complaints about extending your rappel. But Americans don't want to listen to anyone else because 'Murica.

Good point about overlong extensions.

It seems to me that the robustness of the extended method is increasingly highlighted by contorted and far-fetched attempts to disqualify it. For example, the length of the extension mysteriously influencing a person not to test the integrity of the installation advanced as a “failure mode” of the extended system.

Nor does the fact that people have done something "forever" make it the most intelligent choice. The "forever" during which climbers use no backups for their rappels is many times longer than the "forever" during which a device was attached to the belay loop. Which of these "forever's" should we view as definitive?

In addition to some of these increasingly labored objections are some that seem to be wrong. By and large, transitioning from rappel to ascent is of the same minor difficulty no matter where the device is. But if you are using an atc-type device with a guide mode, then the extended position makes it easier, not harder, to make the transition. See, for example, blog.alpineinstitute.com/20…. (The article doesn't mention that wrapping the brake strands around a foot and standing up will make the transition possible even if the rappel is free-hanging).

I think rob.com and Em's objection about the device possibly hanging on certain types of lips is the only significant problem mentioned so far (and I apologize to rob for snarkily suggesting that his comment boiled down to a concern about scratching the device). It is hard to get a device to hang up this way (it has never happened to me when using an extension and I’ve rapped over a lot of lips), but it is not inconceivable if you have a transition between a low-angle slab and steeper rock below and you are using an overlong extension. In that case the weight on the rope from a hanging climber might possibly pin an extended device to the slab above. If a crack runs through the rock at this transition point, something the device could drop into and wedge, then you'd have an even worse problem. I’d be interested to hear if anyone has actually gotten stuck in this way.

As the objections to extension become more far-fetched and labored, I’m becoming increasingly uncomfortable as a “defender.” I’m not dogmatic about any aspect in climbing. My current device of choice (the CT Alpine UP) serves as an excellent rappel backup, and of course I use it directly on the harness. When I use my DMM Pivot, I typically extend the rappel (not past face level) but only rarely use an autoblock backup. I find the extra friction advantages of the extension, the more comfortable hand positions—-both on the brake strand, the ability, with thin ropes, to increase rappel friction in mid-rappel, and the potential, if needed, to install an autoblock backup in mid-rappel---one that will not fail because of collision issues---all make this the best method for me.

If you are going to use the belay loop/leg loop combination, make sure the various proportions eliminate collision potential when the system is actually called on to stop you, even if your leg is raised for some reason, and if you have leg loops with buckles, make sure the autoblock is installed in a position that won't just pull open the leg loop.

The thing that causes me not to feel too much concern over leg-loop backups is the fact that guaranteeing such proportions really isn't that difficult since I always use the same biner, cord, and device. Pre measured in this way, this system affords an acceptable level of risk and comfort compared with no backup, and a greater degree of ease and familiarity compared with setting up an extended rappel. As far as broad/standardized practices, I'll concede that you may have a point that the extended system is safer and thus should be taught/encouraged. Knowing how the AMGA works, I can see a similar line of thinking to lowering on sport routes and can understand why they would take this position.

rgold wrote:I’d be interested to hear if anyone has actually gotten stuck in this way.

I have not personally gotten stuck, but one climb that screamed out as a red flag for this possibility is the rappel at Willow Springs in Red Rocks that descends the line "Kemosabe." Slabby terrain over a large lip/roof, as you note.

mountainproject.com/v/kemos…

rgold wrote:As the objections to extension become more far-fetched and labored, I’m becoming increasingly uncomfortable as a “defender.”

I'll join that defense and say I think the extension is really the way to go as well as the time/material costs are not large and the versatility of a tethering system is a benefit for those times when I'm actually rappelling (ie. multipitch descents).

For single pitch terrain, I find myself with few reasons to rappel as well as few needs to extend the belay device when I do. My Mega Jul is often at hand, which means I can use it directly on my belay loop with benefits similar to an autoblock (as is possible with the Smart, Alpine Up, etc.). If I'm single pitch climbing, I also frequently have my GriGri with me, in which case a rappel with the GriGri on a knot-block works nicely, too.

The arguments about an extension resulting in an anchor changeover accident are mitigated by the system in the link I posted on the first page (repeated below), which doesn't require an extension (or rappelling, for that matter).

americanalpineclub.org/reso…

rgold wrote:Good point about overlong extensions. It seems to me that the robustness of the extended method is increasingly highlighted by contorted and far-fetched attempts to disqualify it. For example, the length of the extension mysteriously influencing a person not to test the integrity of the installation advanced as a “failure mode” of the extended system. Nor does the fact that people have done something "forever" make it the most intelligent choice. The "forever" during which climbers use no backups for their rappels is many times longer than the "forever" during which a device was attached to the belay loop. Which of these "forever's" should we view as definitive? In addition to some of these increasingly labored objections are some that seem to be wrong. By and large, transitioning from rappel to ascent is of the same minor difficulty no matter where the device is. But if you are using an atc-type device with a guide mode, then the extended position makes it easier, not harder, to make the transition. See, for example, blog.alpineinstitute.com/20…. (The article doesn't mention that wrapping the brake strands around a foot and standing up will make the transition possible even if the rappel is free-hanging). I think rob.com and Em's objection about the device possibly hanging on certain types of lips is the only significant problem mentioned so far (and I apologize to rob for snarkily suggesting that his comment boiled down to a concern about scratching the device). It is hard to get a device to hang up this way (it has never happened to me when using an extension and I’ve rapped over a lot of lips), but it is not inconceivable if you have a transition between a low-angle slab and steeper rock below and you are using an overlong extension. In that case the weight on the rope from a hanging climber might possibly pin an extended device to the slab above. If a crack runs through the rock at this transition point, something the device could drop into and wedge, then you'd have an even worse problem. I’d be interested to hear if anyone has actually gotten stuck in this way. As the objections to extension become more far-fetched and labored, I’m becoming increasingly uncomfortable as a “defender.” I’m not dogmatic about any aspect in climbing. My current device of choice (the CT Alpine UP) serves as an excellent rappel backup, and of course I use it directly on the harness. When I use my DMM Pivot, I typically extend the rappel (not past face level) but only rarely use an autoblock backup. I find the extra friction advantages of the extension, the more comfortable hand positions—-both on the brake strand, the ability, with thin ropes, to increase rappel friction in mid-rappel, and the potential, if needed, to install an autoblock backup in mid-rappel---one that will not fail because of collision issues---all make this the best method for me. If you are going to use the belay loop/leg loop combination, make sure the various proportions eliminate collision potential when the system is actually called on to stop you, even if your leg is raised for some reason, and if you have leg loops with buckles, make sure the autoblock is installed in a position that won't just pull open the leg loop.

To clarify, I do not object to extending the rappel. I think it is a perfectly safe and valid method to use. I also do not advocate that everyone use a leg loop back-up. I was simply answering these questions:

1.

rgold wrote: What then, besides the having a possibly less-scratched device, are the distinct advantages of the belay loop/leg loop setup that would make it the method of choice over the extension?

2.

rgold wrote: I'm not sure how that works out to an "extra margin of safety."

It seemed helpful to clarify that the problem over a lip was not a scratched device as you had originally interpreted. I have actually witnessed climbers getting stuck in this fashion on two separate occasions. I have never seen someone invert while rappelling, but I absolutely believe it could happen. I would venture to suggest that the entirety of what rgold and I have personally witnessed combined is a statistically insignificant sample size.

I also understand that rapping off the belay loop and autoblocking off the leg loop has disadvantages and potential failure modes, I just didn't need to explain those since rgold already did a great job of it and nobody was asking those questions. I believe you asked why anyone would ever choose it, and so I gave some reasons why I often choose it, for the purposes of discussion not for the purposes of criticizing other methods.

What I AM advocating is this:

Em Cos wrote: Obviously every method has pros and cons, and can mitigate some risks while introducing others. Which is why I advocate knowing many methods, knowing what the pros and cons are, and choosing which to use in each situation with a full understanding of the benefits and risks.

I almost always extend and attach the autoblock to the belay loop. In fact, the few times I don't do that is because I don't have the requisite gear with me, which is quite rare.

The right extension for me is about 25 cm (or 10 in). (See David Coley's post up-thread.) My autoblock cord is cut to size, so that it does not interfere with the rappel device. Because the extension is short, I have no problem when passing overhangs: the rappel device is lower than my nose. I have no problem weighing the system before I unclip my tether. The gear I use consists of a double-length sling girth-hitched to my harness's tie-in points, with an overhand tied in it at the right distance. This sling also serves as my tether and therefore has a locker on it to clip in to the anchor. In spite of the short extension, I have no problem keeping both hands below the device, which is a major point in favor of extending.

Most of the advantages of this setup have been already mentioned, but one thing I like about it apparently has not. (This advantage applies also to the case of autoblock attached to the leg loop.)

When rappelling, I always rig the autoblock first. Then I pull an armful of rope through it. I verify that the autoblock catches, thus supporting the weight of the ropes, and then I proceed to thread the slack ropes through the rappel device. (I suspect we've all seen climbers struggle and fumble trying to thread taut ropes through their devices.)

While I only recall one case of rappel device failure--and that was a figure-8--I also recall at least one case in which incorrect threading of the device resulted in a fatal accident. I like the idea that my autoblock is connected to my belay loop should I have a major brain fart.

Concerning the case in which the rappeller went too far down and wants to re-ascend the rope--which has been touched upon by 20kN and rgold--it's fair to say that if you do not make the transition to guide mode, then the shorter the extension, the less effort is required to pull rope through the device. On the other hand, if the rappel device supports "guide mode," and there's a locker to spare, making the transition is not at all a bad idea.

Oftentimes, a properly implemented procedure is safer that a better one that is poorly understood or executed. I'm not going to suggest that a climber who has one system perfectly dialed should change. I only want to point out that the extension of the device has served me quite well for several hundred rappels and that I haven't been affected by any of the drawbacks that have been mentioned in this thread.

Em, for the record, I wasn't addressing your responses...

No worries, then I apologize for my response - especially if the tone seemed anything less than cordial. I'll leave my post there though as I did realize that someone could get the idea that I thought extending was a bad idea, and I didn't want to give anyone that impression. :)

Em Cos wrote:I have never seen someone invert while rappelling, but I absolutely believe it could happen.

Inversion is a not uncommon issue for noobs rappellers on school camps etc. Especially if there is a overhanging lip involved in the rappel. Not really relevant in for most climbers.

I've seen somebody invert as she abseiled through the centre of a waterfall with a focused flow. She essentially got waterboarded without having to visit guantanamo. She was a novice but not incompetent, a bottom belay was being provided. I still remember the look of fear on her face as she righted herself, I was just above her watching her go down.

Also inversion or partial inversion can be quite likely if you are incapacitated. Which is one of the reasons proponents of autoblocks produce. (eg rockfall.) Either way it is is not at all unlikely in many of the times you need an autoblock.

(1) requires extra gear you need to bring (an extra sling); (2) adds an extra point of gear failure (the sling);
(3) adds additional steps to the rappelling process,

1. Sling I already carry, nothing "extra" about it.
2. point of gear failure, the slings I count on to catch a leader fall?
3. No.

Alex's initial post is incredibly off the mark. Point 3 about additional steps to rappel process is the worst.

Here are some relevant comments from a discussion on UKC:

ukc post wrote:I've seen leg loop attached prusik loops fail twice. Both times when some one was leaning a long way over to reach something and took both hands off the system (a stuck piece of gear and the rest of the abseil rope in a tree).

This is very likely the type of situation that caused the fatality I mentioned earlier. The lesson is that your setup has to be checked for extreme positions and not just the ordinary hanging rappel posture.

The same post mentions a potentially serious problem even with an extended device:

ukc post wrote:Equally there is a discussion on an Instructors' FB page at the moment which references several incidences of the sling extending a belay plate away from the belay loop coming in contact with belay loop attached prusik knots and causing sudden release.

This makes my claim about the logical superiority of the extended rappel less absolute. Not to start up another argument, but things like this reinforce my feeling that if you use a rap backup of any kind, it should be there to (hopefully) intervene in an involuntary loss of control, but should not be used as an every day way to go hands-free unless you are going to add leg-wrap backups.

rgold, I have moved my 3rd hand to my belay loop. Attached to the leg loop there are scenarios where body twisting could change the distance of the backup to the device. Putting the backup on the belay loop maintains a more constant distance. The only thing left is user error making their backup too long. I don't know how to prevent that.

rgold wrote:if you use a rap backup of any kind, it should be there to (hopefully) intervene in an involuntary loss of control, but should not be used as an every day way to go hands-free without leg-wrap backups.

I completely agree on the leg wraps, but I wonder where the extension sling was attached when it caused the release of the autoblock. (Perhaps it was also connected to the belay loop?)

Another observation is this: There are many cases when I rappel first and need to readjust the fall path of the rope in which I don't need both hands. I still find it convenient to let the autoblock engage so that I don't need tension on one side of my body just to avoid losing height.

Rick Blair wrote: I have moved my 3rd hand to my belay loop. Attached to the leg loop there are scenarios where body twisting could change the distance of the backup to the device. Putting the backup on the belay loop maintains a more constant distance. The only thing left is user error making their backup too long. I don't know how to prevent that.

David Coley mentioned 30 cm, which is a foot. I'd keep it at or below eye level in any case.

brenta wrote:I wonder where the extension sling was attached when it caused the release of the autoblock. (Perhaps it was also connected to the belay loop?)

I don't know any more than what is in the quote---before that I'd never heard of the sling releasing the knot. If I find something I'll post it.

I'm not sure how that person managed to get their prussik up to their belay device if the belay device was extended and their prussik was attached to their belay loop (this should make it a fixed distance unlike if it were attached to the leg loop)? The only thing I can think of is that they did not double check that their prussik could reach their belay device. In which case either their prussik cord was too long or their extension was too short, I'm going with almost certainly the former. I wouldn't count this as a possible failure mode for a properly set up rappel because if the prussik can reach the belay device from the "normal" position then it is not properly set up.