Rappelling accident using Mad Rock belay device.

Scott Dusek wrote:

The noob questions should definitely be answered as they come up - that is critical! It causes major drift but the point of these threads is to learn. Your disclaimer about weight is nice and shows sensitivity. However, the post above yours is flat out, dead on accurate. Just replace, "too fat" with, "too heavy" and it's the best summary of this accident in the whole thread. 

-Was the autoblock tied improperly? It appears so.
-Should extra, or different biners been used? Yes and they were not.
-Would a leg wrap (or three) have helped? Immensely!

All good points - that YOU should know about and have in your bag of tricks.

However, the guys was too heavy for the setup, period. That is the beginning and end of it. Being correctly connected is NOT the same thing as "rigged properly". He was never rigged properly because the system was not adequate for his needs.

100% user error - 0% fault Mad Rock (stupid fucking thread name BTW)

Fireman's belay: he was the heaviest, was expected to be experienced and know what he was doing, and thus thus the obvious choice for the first one to rap. This is standard practice in the Alpine world (it allows the rappel anchor to be backed up and "tested" by the heavier climber). Unless you are an exceptional trainer of marmots there is no one down there to give a fireman's belay. Will they consider not having him rap first on a single line now? Yes they will. If you know your anchor is bomber and you are on a single strand with a heavy partner perhaps the lighter person rapping first makes good sense. Point is that the existing ethos is that the heaviest should rap first provided they understand how to rappel, know where to go, etc. Time to change that? Unlikely, but maybe worth considering.

This^^ But I said it better.

But really, if this was SAR they should have known better.

People need to learn to think ahead and if they are trying something new then they should try with a 100% back up.

Side question....anyone ever meet a svelte fire chief?

Mark Pilate wrote: Side question....anyone ever meet a svelte fire chief?

Now that’s a vision. :)

Tradiban wrote:

This^^ But I said it better.

But really, if this was SAR they should have known better.

People need to learn to think ahead and if they are trying something new then they should try with a 100% back up.

Wow, deleting posts so you can say it better? C'mon tradi, say it better again!

If you are heavy...or have ever rapped with a haul bag...you should know..add friction.

The fact that this guy ever smashed through the trees screams dumbass relying on dumb fireman training.

As a climber...you should add extra friction.

As a fireman...you need to get beyond believing in training and think for yourself.

I have climbed with a fireman and marine guy that have taught me a lot.

But that government training mentality is also going to kill them too.  

You have got to be able to say to yourself "this plan is not working" and reconfigure.

Those rule follower types  just can't reconfigure.  They are like..."I am following my training"...and they don't adjust when it is clearly not working.

So be well trained but be flexible and aware when the training is not working.

Now here are some firefighters!

Mark Pilate wrote: Side question....anyone ever meet a svelte fire chief?

No, I've not met her yet, but she looked pretty darn trim in the photo announcing her promotion! 

Best, Helen

Old lady H wrote:

Dumb questions, but hey, that's what noobs are good at, eh? Does it matter how you wrap a rope around a leg? The one time I tried, just to stop and hang full weight, it wasn't workable.

Question two, I have tied prussiks, and always assumed that if the wrap is holding my weight, at the start, I'm good to go? I've used them to ascend, reverse the ascend, double and single ropes and feel fairly confident about getting those wraps right. Is there a "gotcha" I need to know about?

Thinking about ATCs heating up, does rap speed make any difference, or would the length of the rap make the same heat, fast or slow? I'm slow on raps, walk down, no rocketing.

For those who use a grigri on a single line rap, how would you test it before launching? Have enough slack in your tether to lower a bit?

Last, I'm assuming a tandem rap needs lots more friction? I'm sorta surprised the Chief wasn't thinking about weight, since SAR stuff is always uber redundant and much more tuned to loads (zero offense meant, Chief!).

Truly sorry for the Chief's accident. I'm glad they dug into it thoroughly.

Thanks! Helen

Total amount of energy into the belay device doesn't change. The device is just converting your potential energy (mgh) into heat as you lower. However, it's dissipating heat the whole time. If you rap really fast, there's not a lot of time for it to dissipate heat, and it will get hotter. If you rap slowly, it has much more time to dissipate heat, and will remain cooler as a result.

Tim Stich wrote: Of course the issue with rappels over 150 feet on devices like ATCs and regular figure 8s is overheating and the resultant decrease in friction

Tim, do you know any more about the configuration this 150' number refers to ?  Things like climber weight, single-vs-double-strand, rope diameter, rappel speed, etc.  

Serge Smirnov wrote:

Tim, do you know any more about the configuration this 150' number refers to ?  Things like climber weight, single-vs-double-strand, rope diameter, rappel speed, etc.  

No, unfortunately, but it's probably out there in some test data. It was just a rule of thumb I learned in caving not to do longer rappels with our figure 8s and instead use a rappel rack. 

I did read a response from chief in the Facebook group rope test lab. He explains that he simply didn’t do it and he have no idea why even though he knows how to ad extra friction.

My personal, new Gumby climber thought is that tiredness, a improperly setup auto block (the burnmarks on the stitching) and a heavy load all contributed to the accident 

Mads Hvid wrote: I did read a response from chief in the Facebook group rope test lab. He explains that he simply didn’t do it and he have no idea why even though he knows how to ad extra friction.

My personal, new Gumby climber thought is that tiredness, a improperly setup auto block (the burnmarks on the stitching) and a heavy load all contributed to the accident 

Friction hitches cannot activate at high speed is my understanding so their safety advantage in a case where control is lost may be minimal.

Harumpfster Boondoggle wrote:

Friction hitches cannot activate at high speed is my understanding so their safety advantage in a case where control is lost may be minimal.

Would you please share a source or background data for this?

Some things to think about---by no means complete...

1. Don't try something new without a belay.

2.  If you use fingerless gloves, you will burn your fingers if you lose control.

3. Autoblock backups only work if you let go with the hand that is dragging them along, otherwise they do nothing. Once you are moving fast, even letting go may not cause an autoblock to engage. *  Folks put way to much trust in these in general, but your best chance is to use an extended rap device with the autoblock on the belay loop.  With this set-up, the non-brake hand is dragging the autoblock, and this means you can let go of the autoblock and grab the brake strand with both hands (practicing this would be sensible).  This action doubles your braking power and hopefully will activate the autoblock if you aren't moving too fast.  If the autoblock is on a leg loop, it will be dragged with the brake hand, which won't be released and so the autoblock will never engage.

4. Leg wraps are good for stopping when you are still in control,  but are hard to get on once in motion and free-hanging, at which point there is a risk of fumbling the brake strand completely and losing all semblance of control.

5. If you sense any trouble at the beginning of the rappel, stop immediately (this is the moment for leg wraps), because things will get worse and worse as brake-side rope weight decreases. Ascend back up (you"re only a few feet down at this point) and re-rig with more friction.

6. If you aren't sure and have to rappel, begin with a high-friction setup, as too much friction is WAY better than too little!  This means at least two, maybe three carabiners for an extended rap device, then running the brake strand down to a carabiner on the belay loop, back up to a carabiner at the end of the extension, and then down to the brake hand.  This has the unique advantage of being undoable and redoable while rappelling, and if you have more carabiners you can even multiply the zig-zags.

* Tammy's comment about high speed not being an issue is wrong in my experience.  The question is what is moving.  In the 600 pound drop test, the weight is moving but the prusiks are stationary.  That's not the problem here though, when the rappeller has inadvertently started the prusik moving down the rope.  Once this happens, a friction knot may or may not catch if it is ever released.

Tricky tricks:

1. Put an overhand slip knot on the rope ten or fifteen feet down.  (Clip a carabiner to the slip not loop to keep the knot from undoing from rope weight).  If the rap heads south, the knot will stop you.  If all is well at the knot, unclip the carabiner, collapse the slip knot, and continue on your way.  (But beware of the effect of little rope weight at the end of the rappel.)

2. Hang something heavy on the end of the rope.  Not so heavy that the rappeller can't move, but heavy enough to provide a more or less constant fireman's belay effect.

Bret Files wrote: why would you put the friction hitch (whatever your chosen variety) on the brake strand instead of out in front of you on the load strand?

Putting it on the brake strand allows you to rappel 1-handed (same hand controls the brake strand and tends the friction hitch), leaving the other hand free to manage the rope / push off the side of a corner / etc.  Also, a friction hitch on the load strand is harder to release if you accidentally let it catch.  Finally, the panic failure mode of squeezing the friction hitch with your hand is more of a guaranteed disaster when the friction hitch is on the load strand (on the brake strand, there is a decent chance the squeezing force will actually stop the rappel).

You are absolutely correct that putting the friction hitch on a leg loop has many issues of its own, which is why the method generally considered safest is to put the friction hitch on the belay loop (below the rappel device), and the rappel device on an extension.

Bret Files wrote: Anyway, to the question: why would you put the friction hitch (whatever your chosen variety) on the brake strand instead of out in front of you on the load strand?  As I learned it (meaning someone mentioned an esoteric technique that no one ever did) either was acceptable and it has always seemed to me that putting  it on your leg loop/brake side is asking for it to get sucked into the device if you wiggle around too much.  Likewise, getting both hands down by my right hip to brake and ride a hitch is awkward as hell (this is probably an artifact of 20 years of clipping my device through  hard points instead of belay loop thus orienting the brake strand to the side instead of down).  Anyway, it still seems better to clip a slightly longer hitch to your harness front and run it out onto the load strand and then ride it with your non-braking hand out in front of your face.  In the interest of learning a better way, what am I missing?

The answer isn't as simple as some folks would like to make it, but one thing is for sure: putting the autoblock underneath the rappel device means it is subjected to a significantly lower load if called upon to function, and so is less likely to malfunction in that position.  If you are playing the odds, this should be enough reason all by itself---if you have bought into the backup protocol at all.  

All the stuff about colliding with the device is very true, but extending the rappel solves that issue and provides a bit of increased friction for free.  Using the hard points is not the best idea; locking carabiners have been pried open in the field in that position (but mostly by figure-8 devices which have become pretty uncommon), so the belay loop is a better bet.

Wherever you put the autoblock, it won't do anything unless it is released by the hand that is dragging it.  In the extended set-up, both hands are quite close together and it is reasonable and feasible to release the autoblock with the non-brake hand and grab the brake strand just below with both hands.  This is harder and less likely to happen under sudden stress if the non-brake hand is up at face level or higher and the brake hand is way down at the hip level and the belay device is in between them.

A lesser issue with the top autoblock is that folks sometimes make the sling too long and the autoblock locks up out of reach above, causing a mini or maxi epic to ensue, depending on the skills of the rappeller.  There is also the issue of going over a lip.  An extended device can grate on the face above in a disconcerting but not actually dangerous way, and both hands are below the lip when this happens.  But with the high autoblock, you've got a hand above the lip dragging the autoblock and now pinched between the ropes and the rock.  This can hurt, but if you let go the autoblock locks and you can't continue.  Meanwhile, you are scraping the rope or webbing of the autoblock against the rock, rather than a metal belay device, and this is, or ought to be, more worrisome.

At the end of the day, the two methods are both ok if you understand what they can and can't do.  Neither is very good at dealing with a loss of control because of inadequate friction, their main utility is for saving a rappeller who has been knocked out.  (And of course nowadays they are used for mere convenience in stopping, although leg wraps are probably safer for that.) Neither, by the way, will stop you from rapping off the ends of an unknotted rope.    The extended-rappel-autoblock-on-the-belay-loop is, on balance, a better configuration, and is at least a little more likely to function when it is needed.

sounds like they need some outside training.. 

If you are going to use a backup, then you need to be able to engage it when it is needed. Few will be brave enough to just let go. And this might not be wise as it might not look. More likely you would let go very slowly with both hands initial on the brake strand (as you were trying to control a semi out of control situation. To fit the auto block in the deployed starting-to-grip position and a hand, one kind of needs to have extended the rap device.

The situation is perhaps further complicated by the existence of various assisted-belay devices that provide at least some backup functionality without the need for a separate knot.  How effective these devices are beyond routine non-emergency stops doesn't seem to be known...

Bret,

The previous posts explain well why to use a backup on the brake strand and extension.  Here are a few nuances:

If you know you are going to pass a knot on rappell, it can be advantageous to put the backup above and attach yourself to the backup using a load releasable hitch like a munter mule overhand.  Reference a good self rescue book for details.  Otherwise backup below for a wide variety of reasons.

If rapelling with a plaquette-style device like the ATC guide, transitioning from an extended rap with backup to ascending the line(s) is a simple matter of 1) tying a catastrophe knot below the backup, 2) putting a prussik above the extended device using a long enough combination of materials to make it a foot loop, 3) stepping into that loop and clipping a locker from the guide-mode loop to your belay loop.  Voila, you are ascending and can transition back to rappell by reversing those simple steps.