Accident Report - Rigging Failure During a Rappel

[bjp]

The figure eight, as far as I know it, its pretty "locked off" when you twist and put a sort of half hitch into it to secure the loop. And, I have always seen folks then clip that off as well, securing it for all but the last person.

Who has a good photo of a locked off figure eight, or, the current Stefan Hofmann riggin' of it? Post up!

Thanks.

Perhaps the photos by unripecoconut on the "Figure 8 block with lower" (7/30/2011) thread? A rigging/knot is "locked" when a strand with more tension is pinning a strand with less tension against something else. So it looks to me like the first picture in that thread is not locked off, nor is the demonstration in cerberuscanyons. Tom seems to think it's not important whether the figure 8 block is strictly locked off -- see 4/30/2012 response to unripecoconut on the same thread.

Putting a clove hitch in when securing it to the loop would certainly do the job :) A clove hitch is a great example of locking -- the only thing it does is pin the lower-tension strand against the thing it's hitched on using the higher-tension strand.

[Scott Card]

You're talking apples and pomegranates.

Sandtrap:

.......
Joker/Jester:
.......

That would be a nice system, if it worked.

Tom

Tom, it does work. It really does. My compairison was not apples to pomegranates in the sense of equipment to equipment but the comments against the sand trap and the comments against the Jester seem to be very, very similar --particularly by those who haven't tried it (or them). This accident is quite the head-scratcher for me since I have actually used the Jester multiple time to send people, youth and adults alike, down rappels, the most recent a group of twenty or so girls. Not even a tiny slip of the rope. I know, I watch these things like a hawk. Liability is/ was a major concern for someone like me. Just for fun, I think I will mark the rope at the rapide and then check the back and forth of the raps when I use this again. *edit. I think I will add a biner block just to complicate things more on each strand just in case as I test this thing out with my ropes. Off to my swing set this evening. Wish I had a video... well actually I don't. This will look pretty stupid to the neighbors.

[ratagonia]

Bjp - you have test equipment?

Tom

[bjp]

You're talking apples and pomegranates.

Point taken -- fancy anchors are for special circumstances and users are taught to be extremely careful with them, while the Jester may have been represented as a rope-agnostic tool that can be used often. People should take note of ag23's discovery that friction slipping occurs in the Jester at unacceptably low tension with some ropes.

Joker/Jester:


This is a technique that people are trained to, using a specific piece of gear (Totem)

Well, I use it all the time using two overlapping opposed standard figure 8's (not a Totem). And my use case is the same -- beginners in large groups. So, I'd definitely be interested in whether you think the Joker is also a rigging that people shouldn't be using frequently.

The Figure-8 blocks I have seen have an extra loop of rope that acts as a lock. It is not just friction partly because there is rope-across-rope interaction that tends to lock with more force.

It's not just rope-on-rope that does the locking, it's high-tension on low-tension (like in the clove hitch). Most figure 8 blocks I've seen don't have this locking feature -- I'd be interested to see a picture of one that does.

To me, the other difference is that the Jester method is offered in a place where many other riggings could be used. Does this have advantages over other methods? Yeah, I can see that it would be great to have a system that sets up quickly, allows both strands to be used independently back and forth, AND provides contingency setup on each of those strands. That would be a nice system, if it worked.

Well, we can essentially always come up with other ways of doing things; it's just a matter of which way has the most advantages (including such advantages as "I know how to do it this way") How do you defined "worked"? Clearly the Jester doesn't work with all ropes and rigging variations, as ag23 has shown. But it works with a lot, and so does the Joker.

[bjp]

Bjp - you have test equipment?

Tom

Sorta -- a 2000 pound tension gauge and a come-along. I occasionally have access to a 10k pound puller.

[ratagonia]

Tom, it does work. It really does. My compairison was not apples to pomegranates in the sense of equipment to equipment but the comments against the sand trap and the comments against the Jester seem to be very, very similar --particularly by those who haven't tried it (or them). This accident is quite the head-scratcher for me since I have actually used the Jester multiple time to send people, youth and adults alike, down rappels, the most recent a group of twenty or so girls. Not even a tiny slip of the rope. I know, I watch these things like a hawk. Liability is/ was a major concern for someone like me. Just for fun, I think I will mark the rope at the rapide and then check the back and forth of the raps when I use this again.

I see your point, but...

I would say that we have an instance of it failing, therefore it is incorrect to say "it works". You have used it extensively, and it has NOT YET failed on you. I think this is a good thing.

I hope to do some testing on Sunday if we can find the dynamometer.

My suspicion is that the method is not "robust". Like Humpty-Dumpty, I have my own meaning for this word. The Jester fails under some circumstances. We have not yet revealed which circumstances. My suspicion is that the small rigging variations Andre made coupled with a new, smallish rope yielded a failure. A robust system is one that can be rigged slightly wrong or used with carabiners and ropes that are a little off-the-norm, and still work.

Now that YOU have been notified that there is a possibility it does not work in all reasonable circumstances, may I presume that you CANNOT use it until this has been investigated fully, and you will be going back to the Stone?

Tom

[Scott Card]

I see your point, but...

I would say that we have an instance of it failing, therefore it is incorrect to say "it works". You have used it extensively, and it has NOT YET failed on you. I think this is a good thing.

I hope to do some testing on Sunday if we can find the dynamometer.

My suspicion is that the method is not "robust". Like Humpty-Dumpty, I have my own meaning for this word. The Jester fails under some circumstances. We have not yet revealed which circumstances. My suspicion is that the small rigging variations Andre made coupled with a new, smallish rope yielded a failure. A robust system is one that can be rigged slightly wrong or used with carabiners and ropes that are a little off-the-norm, and still work.

Now that YOU have been notified that there is a possibility it does not work in all reasonable circumstances, may I presume that you CANNOT use it until this has been investigated fully, and you will be going back to the Stone?

Tom

Hence my edited comment above... isn't the answer a biner block? I will test it on myself under a controlled environment with soft grass below my swingset hut. This sounds down-right scientific! Prepare for a big boned canyoneers' findings to come.

[ratagonia]

Hence my edited comment above... isn't the answer a biner block? I will test it on myself under a controlled environment with soft grass below my swingset hut. This sounds down-right scientific! Prepare for a big boned canyoneers' findings to come.

I use a Stone Knot as my #1 rigging these days. Biner block #2.

T

[bjp]

I hope to do some testing on Sunday if we can find the dynamometer.

If you have extra time/patience, I would personally find it extremely useful if you might consider testing the opposed-figure 8's version of the Joker. If you can't, I'll try testing it next time I pull on stuff.

[ratagonia]

How do you defined "worked"? Clearly the Jester doesn't work with all ropes and rigging variations, as ag23 has shown. But it works with a lot, and so does the Joker.

I have a higher standard than "works with a lot".

Could you post a picture of the Joker you are using? Or is it the Jester?

Tom

[Scott Card]

I use a Stone Knot as my #1 rigging these days. Biner block #2.

T

I need to learn the convert to lower from a Stone Knot you speak of. That one for sure I can't picture in my mind.

[ratagonia]

Maybe Brian could post a picture (however poor) of the Figure-8 block method he is currently using.

Tom

[bjp]

Could you post a picture of the Joker you are using? Or is it the Jester?

Tom

I use the Joker; I don't have a Totem. I'll try to take one tonight. In terms of a description: start with the rappel rope passed through the quick link. Clip one side of a quick draw onto the shelf of an anchor and the other end to the big holes of two figure 8's. Rotate each of the figure 8's 90 degrees in opposite directions so that the little holes are on opposite sides but the big holes are still overlapping ("Mickey ears"). Make a bight on one of the rope strands, pass it through the big holes, and then around the little hole of one of the figure 8's just like you would when rigging for rappel. Repeat symmetrically for the other strand. Clip a quick draw to both little holes as a safety if desired.

Basically, it's identical to the Jester except that the two sticht plate friction points are replaced with figure 8's. But come to think of it, I'm not sure why the big and little holes couldn't be reversed for a bit more friction; I'll have to try that.

Also, looks like I'll be able to use the 10k puller next week. I have the samples of all your ropes; want anything broken? :)

[Brian in SLC]

Fiddlin' about...here's the Rock Exotica smallish eight, rigged with a tie off on the T post. Kinda neat:



ATS rigged ala Jester, methinks:



Some rap device (Trango?) rigged ala Jester as well, methinks:



Note the two above don't hold me, but, slip when rappelling single strand. Tom, recognize the cord? Its your old friend the teal trail line! 8mm. My guess is the friction holding of the Jester is very (VERY) rope diameter, and, maybe rappeller weight, dependant.

How I've rigged an eight, but, not sure if other folk do it this way, or, that its Stefan's way:



Cheers!

[ratagonia]

Thanks.

Yes, nice Teal "Trail Line". What a piece of junk. Sorry I ever had anything to do with that. I would call it 7.5mm by today's standards!

T

[Brian in SLC]

Yeah, that rope is the one we harvested from being cut off and left in a canyon. Great for living room/stairwell use!

[Bo_Beck]

Hey Beck! Did I say that I use the thing? And why am I suddenly having to defend learning basic techniques (this is not a basic technique but rather a use for the totem) ? In the context of these Canyoneering courses, a lot is thrown at relative beginners over a short amount of time including the use of many devices. BTW...I like the M/M but if you are stupid, you could really screw that up too!

BW

I apologize BW. I read what you said about Rich showing you 5 incorrect ways that the Jester could be set up, and just wanted clarification as to the correct way so that if at any time I was with someone insisting that we use this system, I might be able to understand if it were rigged properly or not? Once again...no mal-intent directed toward you.

[Bo_Beck]

Forgive me if I spoil anyone's fun by providing accurate information ...

https://www.facebook.com/AmericanCan...ingAssociation

Feel free to copy any of the Jester rigging photos from the Facebook page and paste them here to continue your discussion.

Carry on.

Thank you very much Rich!!!!!! You've answered my question which seems to be eluded to in this conversation! Makes total sense what this rigging is used for now!

[Slot Machine]

I need to learn the convert to lower from a Stone Knot you speak of. That one for sure I can't picture in my mind.

X2

[Slot Machine]

The Jester and Joker are releasable versions of the Stone knot -- all three isolate both strands allowing people to rappel on either strand while the Munter/Mule does not. The reason one might want the option to rappel on both strands is to have someone rappelling at all times in a big group; the next person rigs while the previous person is on rappel. This is extremely useful in certain circumstances, like taking a group of 12 through Little Santa Anita with 10-12 small rappels.

I can only speak from personal experience, but I find it much easier to rig, teach others to rig, and check the Joker than a Munter/Mule. Like the Joker, the Jester essentially has just 3 simple steps -- clip Totem to anchor, push rope into sticht slots, clip carabiner through bights. The Munter/Mule has 4 steps and more details to get right -- clip quickdraw to anchor, tie Munter with rappel strand to lower carabiner, tie a slip knot with a bight from between the lower carabiner and quickdraw, tie an overhand with bight.

Ah, you forgot the new important fourth step, hope it holds and pray you don't die. I joke, I joke...

Really, this is the best "for" argument on the thread so far. I'm not sold yet, but thanks bjp for answering my question.

I'm looking forward to these fancy test results.