Tuesday, July 6, 2010

Rappelling on Skinny Ropes

Super skinny ropes are becoming more and more common among high-end alpinists. Twin rope systems provide a climber with the ability to do double-rope rappels with just a bit more weight than a single line. They provide additional security should one of the lines get cut or damaged during a lead. And lastly, they are a bit slick when it comes to rappelling.

It's this last item -- providing more friction on the rappel -- that we will address in this blog today.

As with most of the things that we address here, there are many ways to add friction to a standard device. The first and most popular way is to simply add a second carabiner to the rappel. This decreases the size of the holes in your belay device and increases friction because there is more ground for the rope to run over.

The second way, while less popular, works just as well. In this system, the rope runs in a Z, running down from an extended device to the climbers leg-loop, being redirected back up above the device to a carabiner and then down to the break-hand.

The preceding picture is slightly difficult to see as there is shade on the climber; but you will note that the climber is holding the rope with her left-hand. The rope runs down from above and into the device. From the device it runs through her hand. There is a autoblocking hitch clipped to her belay-loop in her hand. From the autoblock, the rope runs to the leg-loop, is redirected off a carabiner and runs back up to the top. At the top, it is redirected off of another carabiner and the backside goes to the breakhand.

Some of you will probably end up pointing out that the woman in the picture is about to rappel off the end of the rope. Rest-assured, she was on the ground when this picture was taken and was just setting up the system to practice.

In the preceding picture, it is possible to see how the autoblock is engaged and how the rope is redirected back up.

After the rope is redirected off the leg-loop it is then again redirected off of a carabiner clipped to the line coming out of the top of the device.

This is a somewhat complex system to demonstrate here, but if you put it together, it will make sense once you see the ropes moving through the system...

Adding friction to a rappel is an important skill to have. Whether you use this system or add an additional carabiner, it might be a good idea to practice before you actually need additional friction. This will decrease the liklihood of a mistake when doing it for real...

--Jason D. Martin

11 comments:

Tommy said...

Your going to get someone killed! No manufacturer recommends cross loading its carabiners like the one on the top end of that death trap. No manufacturer of harnesses recommends clipping into the leg loops alone like the bottom biner in that pic. Do yourself a favor and seek expert instruction. Don't be mad at my comments... get help so you don't end up dead!

American Alpine Institute said...

Tommy,

There are no cross-loaded carabiners in any of the pictures. And this certainly is not a death-trap. Manufacturers do believe it is okay to clip into a leg-loop for a back-up as long as the leg-loop is not a fast-buckle.

I feel pretty confident that your comments are off base. This technique is absolutely acceptable.

You or anybody else with concerns about what you see here are welcome to call me anytime. 360-671-1505.

Thanks,

Jason Martin
AMGA Certified Rock Guide

Tommy said...

The biner across the BD Guide is crossloaded. You have created a fulcrom out of the carabiner across the guide. What brand of harness is that?

American Alpine Institute said...

That carabiner is not weight-bearing. There is literally only a few pounds on it. You are right though...if there was real weight on the carabiner in this fashion, we could probably break it. I assumed you were talking about a different carabiner because of the fact that the weight is so limited on the one you're referring too. It's understandable that you might think this as I didn't get into the amount of force on each of the carabiners in the article.

It is also important to note that even if the carabiner did break (a near impossibility in this iteration), it would have little impact on the system. The backup friction-hitch would still engage.

This is not the only place where this technique has been written about. One of our guides, Dylan Taylor, wrote about this technique seven or eight years ago for the tech tip section of Climbing magazine. In that article, the editors at Climbing decided that the technique would be easier to understand if you eliminated the extension element. We experimented with it this way in our guide trainings and found that the redirects are a little bit too short for the system to run smoothly. The extension really makes the system smooth.

I'm not sure what kind of harness it is, but it is a fast-buckle. So you actually have to clip the carabiner appropriately to keep it on the safe side. If you click on the picture so it blows up, you will see that the carabiner is clipped on the crotch-side of the harness and not on the buckle-side.

To read about fast-buckle harnesses and the problems with them and rappelling, please click on the following link:

http://alpineinstitute.blogspot.com/2010/06/problem-with-rappel-back-ups-off-modern.html

Let me know if you have any more questions or concerns!

Jason

Hewett said...

Tommy is right. That Wild Country brand harness should not be clipped that way. If you have to do it at least clip both leg and waist swami. Rigging gear that way is dangerous.

A good personal friend died not long ago. Cross loading is cross loading and clipping a harness wrong can kill you.

J.

American Alpine Institute said...

Hewett,

Jason is in the field right now so I am sure he will be happy to respond to you when he returns.

However, I think you are mistaken by what is going on here. The auto-block is working as a rappel backup, and it is safely clipped with a locking carabiner to the belay loop.

Belay loops are full strength, and technically redundant because they have two fully sewn loops on top of one another. Additionally, it is a good rule of thumb that soft goods (ropes, sling, etc.) be tied in via the tie-in points (what you described as the waist and leg swami) and hard goods (carabiners) be clipped to the belay loop.

Your recommendation of clipping a carabiner to the tie-in points would actually create cross-loading, seeing as the belt would be pulling in one direction, the leg loops in another, and the auto-block in a third direction (tri-loading/crossloading).

The only purpose of the carabiner attached to the leg loop in this instance is to help create more friction. If for any reason it failed, the rappel would continue to work flawlessly.

Andrew Yasso
Program Coordinator

Anonymous said...

Your theory is that. Todd thought the same kind of stuff before he fell to his death.

Ignorance can be fixed with education. You can't fix stupid!

J. Hewett

American Alpine Institute said...

J. Hewett,

We do appreciate your concern for safety and for educating people properly; we share that same concern. I believe you are referencing the belay loop failure which occurred to Todd Skinner while rappelling. What happened to Todd was truly tragic, however had nothing to do with what we are demonstrating or what you are suggesting.

If you are referencing someone other than Todd, please give us a last name and we will look the incident up in Accidents in North American Mountaineering and review it. It is incredibly unlikely that it has anything to do with what we are showing in this picture.

The techniques we are proposing are not theory, they are fact. They are beyond appropriate and safe in providing more friction in a rappel system.

We appreciate your concern.

-Andrew Yasso

Anonymous said...

Some truly dumb people in this comment section...

Madhadsman said...

Thanks for the article and the passion in the comments section to all. However, we're not measuring our dicks here, AAI is attempting to provide education and safe techniques to us all. And negative hostile comments towards them doesn't get anything done. Thanks for all that you do AAI.

Cheers,
Matthew

Madhadsman said...

Thanks for the article and the passion in the comments section to all. However, we're not measuring our dicks here, AAI is attempting to provide education and safe techniques to us all. And negative hostile comments towards them doesn't get anything done. Thanks for all that you do AAI.

Cheers,
Matthew