Rappelling accident using Mad Rock belay device.

Tammy Gueterman wrote: 
I've tested various rope and hitch material combinations in controlled conditions for their behavior of when they are minded down a moving rope then released. I have not observed that a hitch that slips when first released at high speed improves any when released at slow speed. Conversely, hitches that first caught at slow speeds always caught at high speed. I really did try to make these systems fail, as that was the more interesting finding. I would encourage you to tie and dress a hitch so that it slips at high speed down a rope, and then see if you can pull it slow enough so that it catches in the same length of rope without changing things like the rope path and direction of pull.

I  misunderstood your point.  My "practical" observation, based on some half-assed tests myself but mostly on a knowledge of several prusiking accidents BITD before mechanical ascenders is simply that once the rope is running through a friction knot, you can't assume that it will stop a fall.  The factors you described may describe the underlying mechanisms, but what climbers need to know is that the backups won't necessarily intervene in a loss of control scenario, even if the knots are eventually released (which they almost never are).

Add to this observations about material, diameter, and tightness of wraps and you have a system with failure modes even in its expected performance. I've seen a surprising (to me) number of climbers rappelling with rigs I don't think would work in an emergency, and I've also noted a much larger group of climbers who don't test the functioning of their backup before starting the rappel.  I worry that the mere presence of an assumed backup can create a sense of security that interferes with the kind of vigilence rappelling ought to demand.

Rgold and Tammy, thanks for the posts! To my ears, your points aren't contradictory, but complementary. Rgolds observations are true, I'm sure, but Tammy's tests may give the "why" of it. Really beneficial!

My "noobish" takeaway? If you are going to use a system, any system, be fairly confident the thing works before you undo whatever is currently keeping you alive. That means a well dressed prussik that holds your weight.

I'm a slooooow rappeller. I like to see what's up with the rope, watch my footing, watch where I'm going, etc, so generally, I much prefer to walk down, rather than Rambo down, fast and big flying leaps. I see a lot of those types of rappels, and people thinking that's a great way to go down, even on a simple top rope lower in the gym. I'm usually down there telling them to stop bouncing off the wall, because they are on the verge of bouncing me off my feet, lol! Such a killjoy....

Best, Helen

I haven't read all the responses, so I hope I'm not being redundant. I got started climbing by rappelling. We didn't quite know what we were doing. We got rope burns, and had trouble controlling our speed. Unlike the chief, we had massive Clog 8's with a lot of surface area, but we didn't know how to use them. The equipment was up to the task, but we weren't. IMHO, it sounds like the chief's choice of rappell device, his weight, and possible unfamiliarity with what looks like a brand new device may have been contributing factors. A small, light device will heat up very fast. The rope won't, (It heats along its length, but the source of the heating, the friction, moves along the rope, and thus dissipates it, as far as the rope is concerned.)  but will absorb heat as it contacts the rappell device, which , as mentioned before, will heat up, and thus allow the rope to slide ever faster. If you are new to this sport, GET INSTRUCTION. KNOW HOW TO USE YOUR EQUIPMENT. Also, ask questions, listen to the answers, and don't take offense if somebody points out mistakes you are making. It could prevent a serious accident. I hope Chief May is going to be alright.

Old lady H wroteMy "noobish" takeaway? If you are going to use a system, any system, be fairly confident the thing works before you undo whatever is currently keeping you alive. That means a well dressed prussik that holds your weight.

There' s an old Jewish saying:  Act as if everything depends on you, but pray as if everything depends on god.  Translated (and order-reversed) into the realm of rappelling, set up and test your backup system as if everything depends on it, but rappel as if it isn't there.

How do you set up a backup system for a, Dulfersitz?

Cosmiccragsman AKA Dwain wrote: How do you set up a backup system for a, Dulfersitz?

It's called your brain.  Suffering now from declining employment.

rgold wrote:

It's called your brain.  Suffering now from declining employment

Lololol
It was a joke son

Cosmiccragsman AKA Dwain wrote: Lololol
It was a joke son

Well aware pops!

rgold wrote:

Well aware pops!

Well then, I guess my brain is fully employed, as well as yours. ;-)

Has anyone mentioned this?

If you're already a significant way down your rap, and you realize you're on the way to going to fast ... increase the angle of the brakestrand from the autostop.  Do this until you stop, realize you have to change something up, wrap the rope around your leg, and address the issue.

Jorge Jordan wrote: Has anyone mentioned this?

If you're already a significant way down your rap, and you realize you're on the way to going to fast ... increase the angle of the brakestrand from the autostop.  Do this until you stop, realize you have to change something up, wrap the rope around your leg, and address the issue.

Nice post and cool drawing.

Fundamentally (imo) the issue is one of over-weighting the combo of rope and device and then (likely) getting into panic-mode. It has been shown that in the panic-mode case the victims often defeat the device or safety backups by clutching at them preventing their proper action.

It is extremely important to know how to increase the friction of your rappel device and this thread has been very useful in that regard. Everyone should learn how to do that at the very start of the rappel if it doesn't feel right and be sure to have those tools on their person.

Your post gives us one more method of maintaining an in control rappel when we unexpectedly find us over-weighting our usual system. Thanks.

Cosmiccragsman AKA Dwain wrote: Well then, I guess my brain is fully employed, as well as yours. ;-)

Hey Dwain, I was speaking in generalities, not about any one person---such as you.    

Nick Goldsmith wrote: sounds like they need some outside training.. 

Ok Nick, you first

rgold wrote:

Hey Dwain, I was speaking in generalities, not about any one person---such as you.   

Your halo there is tarnished, Rgold. ;-)   

 

If only I ever actually had one...

I want to thank the Chief and SAR for putting this out there. It can be difficult to suffer the slings and arrows that can come along with honesty, but if their words help just one other poor soul and perhaps save even a single life, then it would be gloriously worth it. I down own the ad Rock, but think that that advice would apply to many other rappel devices that are similar. I don't have anything new to add to some earlier great points: add a second biner (or a third if it's a long overhanging rap) and doing a leg wrap (or 2) have always worked for me. I also have a Petzl Stop and a Ukranian figure 8 with ears to lock off the rope or add friction specifically for long drops. Regardless, it's important to match the device to the rope you are out with, no matter if climbing or rappelling. I bought extra DMM Bugettes for my climbing partners when I am thinking I might fall on a skinny rope.

The Stop will allow some creep when it gets towards the bottom of the rope although there is a method to tie it off. Both allow great control on descents. The Ukrainian device looks like it was welded in a guys garage (or yard if dude didn't have a garage) and that's kind of scary as I do not use a backup of any sort while rappelling.

Stop:

Similar to below (lifted from Gary Storriks site (http://storrick.cnc.net/VerticalDevicesPage/Rappel/EightPages/EaredEights/EEight1108.html: )


Best to all, but especially to the Chief.

This particular device is called the "Mad Lock" and seems to be a clone of the original model Petzl Reverso.
It has a feature for adding friction (passing the rope over the "hook"), but I don't think that was used.
It has an unusual removable pin for handling smaller diameter ropes.
Here is a review by Chris McNamara:
https://www.outdoorgearlab.com/reviews/climbing/belay-device/mad-rock-mad-lock
It was used essentially like an ATC in this accident, so none of its special features seem to be relevant.
It is a discontinued product, but that does not mean it can't be used safely like other ATC type devices (by a person with proper knowledge).
As mentioned in the accident report, the description of the device said it was OK for 10mm ropes without adding the pin (not sure if that was for two strands or one, or for rappel or autoblock belay usage),
and that could have led to its not being carefully tested when the rappel started.  (Still a user error in my view).

The discussion here on autoblock knots has been good.
I don't use one myself, as I prefer a less complex system, so I can keep my focus on the many other risks during a rappel.