Autoblock backup through haul loop for rappel?


Original Post
Alex Krueger · · Carrboro, NC · Joined Jul 2016 · Points: 0

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...) .

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, which could cause both the autoblock knot and the rappel device to fail to stop the rappel. In contrast, the old method of putting the autoblock on the leg harness would allow the autoblock knot to reach the rappel device if the climber lifted his leg up near the belay device.

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); (2) adds an extra point of gear failure (the sling); (3) adds additional steps to the rappelling process, which increases the chance of human error. Regarding human error, I am particularly concerned about the fact that, when one extends the rappel to clean anchors, the extended rappel carabiner will be very close to the carabiners used for personally anchoring the climber to the bolts. Accidentally removing the rappel carabiner instead of the personal anchor carabiner, or vice versa, could kill you.

Couldn't one avoid extending the rappel device by putting the autoblock on the haul loop in the back of the harness (clarifying EDIT: and looping it around the side of your waist to the rope, i.e., NOT UNDER THE CROTCH)?

My harness (BD momentum) has a rated haul loop in the back. It seems like the perfect spot for an autoblock because the haul loop will always be on the other side of the climber's body from the belay loop, no matter how the climber contorts himself. I therefore think one could attach the autoblock with the haul loop (back of harness), and the rappel device directly to the belay loop. I tested this out on the ground and it seemed to work well.

The only potential safety downsides I can see to putting the autoblock on the haul loop are: (1) if the rappel device completely fails, you will end up hanging by the haul loop (back of harness), but that doesn't seem like a major safety concern, especially if you are wearing a helmet; (2) if someone is not using a harness with a rated haul loop and their rappel device fails completely, the haul loop may in turn fail. These both seem like negligible safety concerns to me.

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.

Do ya'll think this is a safe setup?

Ted Pinson · · Chicago, IL · Joined Jul 2014 · Points: 45

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...

Alex Krueger · · Carrboro, NC · Joined Jul 2016 · Points: 0

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)

Running the autoblock from the haul loop under the legs would indeed be a terrible, nut-crunching idea.

Derek DeBruin · · Unknown Hometown · Joined Jul 2010 · Points: 540

On single pitch terrain, just lower. See:

https://americanalpineclub.org/resources-blog/2016/3/15/5ipkouk0id07cgc3dqks4fljnsgnx6

On multipitch terrain, you'll want that sling to attach yourself to the next anchor anyway (there are many convenient ways to rig this). Consequently, this is effectively a non issue. Plus, attaching the auto block to the back of your harness introduces the failure mechanism of being difficult to reach and visually inspect, making it more likely you'd mess that up than rigging a sling in front. Further, as you note, haul loops may or may not be rated.

If you're really concerned, a "locker draw" makes a convenient and easy extension that's hard to mess up.

Ted Pinson · · Chicago, IL · Joined Jul 2014 · Points: 45

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?

Alex Krueger · · Carrboro, NC · Joined Jul 2016 · Points: 0

Ted asks how I adjust the autoblock as I descend.

I'm using a 19" autoblock loop (sterling hollow block). If connected to my haul loop through a carabiner, it reaches the rope around my right hip (i.e., right about where I'd have my right hand for a rappel anyway).

However, if one was using a really short autoblock loop I can see it being difficult to reach your hand all the way back to the haul loop to adjust the autoblock as you went down.

Alex Krueger · · Carrboro, NC · Joined Jul 2016 · Points: 0

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.

Freddy Brewster · · yosemite, Ca · Joined Jul 2010 · Points: 30

go try this and tell us how it works out for you

Ted Pinson · · Chicago, IL · Joined Jul 2014 · Points: 45

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...

Marc801 C · · Sandy, Utah · Joined Feb 2014 · Points: 0
Scot Hastings · · Las Vegas · Joined Apr 2013 · Points: 5

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.

I still really don't get this "I don't want to carry an extra sling" logic. I have never once been on a climb where a rappel is required (trad or sport) where I didn't have at least one sling, often many, many more.

patto · · Unknown Hometown · Joined Jul 2012 · Points: 0

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.

Besides rappeing IMO is easiest to control with brake hand BELOW the device not to the side which is an older method of rapping... Braking centrally also allows quick switching of the brake hand something that I certainly find advantageous.

Extra slingjust? Use your tether. Prone to failure? Always WEIGHT your rappel before you remove your tether. Helps prevent a whole bunch of screw ups.

squiddo Siddens · · Mountain View, CA · Joined Jul 2008 · Points: 5
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
Daniel T · · Riverside, Ca · Joined Mar 2015 · Points: 15

With the device extended and autoblock below the device you can go hands free if needed.

With the autoblock behind you, your break strand will be at 90deg and will still feed slowly through the device. This will not allow you to go hands free.

I think you are overthinking it.

Em Cos · · Boulder, CO · Joined Apr 2010 · Points: 0

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?

Glenn Schuler · · Monument, Co. · Joined Jun 2006 · Points: 1,070
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.
FrankPS · · Atascadero, CA · Joined Nov 2009 · Points: 15
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?
seanfm · · Unknown Hometown · Joined Jul 2016 · Points: 0

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-loops

Gavin W · · Surrey, BC · Joined Feb 2015 · Points: 23
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-loops
The 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.
Dan Evans · · N Scottsdale, AZ · Joined Mar 2013 · Points: 40

This post gave me aids.

Kyle Tarry · · Portland, OR · Joined Mar 2015 · Points: 87
Alex Krueger wrote: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.
A single sling girth hitched to your tie-ins or the belay loop is the right length. So too is a double sling with a figure 8 in the middle, and you can also use it to clip into the anchor. You pretty much always have a sling with you too. Keep it simple!
Guideline #1: Don't be a jerk.

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