autoblock/self-belay

[Felicia]

up on Latest Rave:

http://www.canyoneeringusa.com/rave

Enjoy.

Tom

Hi Tom,

Would you explain the rope set up in the last picture on the first page captioned: Rapping over the edge, second rap...

Is the biner off the leg loop for rope management or for rappel (friction) control or for both?

On the second page, in the photo captioned: Tom jugs back up to the top, 2nd rappel. what is on the rope parallel to you that appears red in color?

If Sarah descended on the rope coming from the rope bag, how did the rope/pull cord (???) get set on the other side? Would you have carried that down with you when you descended?

Thanks!

[rockgremlin]

Yikes! Got my palms all sweaty! Good stuff!

[ratagonia]

Hi Tom,

Would you explain the rope set up in the last picture on the first page captioned: Rapping over the edge, second rap...

Is the biner off the leg loop for rope management or for rappel (friction) control or for both?

Sarah is using an autobloc on the right-side leg loop. A good tool to know how to use, and it is a little tricky to get right. It is a self-belay system, but also can be used to provide adjustable friction.

On the second page, in the photo captioned: Tom jugs back up to the top, 2nd rappel. what is on the rope parallel to you that appears red in color?

If Sarah descended on the rope coming from the rope bag, how did the rope/pull cord (???) get set on the other side? Would you have carried that down with you when you descended?

Thanks!

That would be the pull side. Since we had pulled the rope about 8 feet before it stuck solid, it seemed wise to anchor the pull side to a tree. Otherwise, at some point, the stuck rope might release and I would fall 8 feet, at the least soiling my pants. This would put a big "load" on the anchor.

I don't usually set up the pull side until the last person goes down. It just gets in the way. In this case, for the main rope, Sarah rapped down to the "rollover", and dropped the main rope when she had a clear view of the ground. I did the same with the pull side combination (a 200' pull cord and a 125' 8mm rope tied together).

Make sense?

T

[Felicia]

Sarah is using an autobloc on the right-side leg loop. A good tool to know how to use, and it is a little tricky to get right. It is a self-belay system, but also can be used to provide adjustable friction.

Thanks - It does make sense.

I can't find an explanation/diagram of the autobloc as depicted in this scenario. (I have found explanations for lowering a second person via an autobloc in mountaineering.) Where would I go to learn more about this?

[trackrunner]

Sarah is using an autobloc on the right-side leg loop. A good tool to know how to use, and it is a little tricky to get right. It is a self-belay system, but also can be used to provide adjustable friction.

Thanks - It does make sense.

I can't find an explanation/diagram of the autobloc as depicted in this scenario. (I have found explanations for lowering a second person via an autobloc in mountaineering.) Where would I go to learn more about this?

This about covers how to tie most of the firction knots

http://www.chockstone.org/techtips/Prusik.htm

http://www.animatedknots.com/klemheist/index.php

It's a helpful tool but should only be used on certain situations. Not something to play with just because it's cool. Not wise to use rappeling in a waterfall or swift water disconects. After the first person is down usually everone else can be fireman belayed. Another way to stop on rappel is the leg wrap.

Discussion on the autoblock knots and application to canyoneering. Note I'm not trying to drive traffic to another forum. Just thought it was a good discussion to answer Felica's questions.

http://www.canyoneering.net/forums/showthread.php?t=93

[Felicia]

This about covers how to tie most of the firction knots

http://www.chockstone.org/techtips/Prusik.htm

http://www.animatedknots.com/klemheist/index.php

It's a helpful tool but should only be used on certain situations. Not something to play with just because it's cool. Not wise to use rappeling in a waterfall or swift water disconects. After the first person is down usually everone else can be fireman belayed. Another way to stop on rappel is the leg wrap.

Discussion on the autoblock knots and application to canyoneering. Note I'm not trying to drive traffic to another forum. Just thought it was a good discussion to answer Felica's questions.

http://www.canyoneering.net/forums/showthread.php?t=93

Excellent information - Thank you!

[ratagonia]

This about covers how to tie most of the firction knots

http://www.chockstone.org/techtips/Prusik.htm

http://www.animatedknots.com/klemheist/index.php

It's a helpful tool but should only be used on certain situations. Not something to play with just because it's cool. Not wise to use rappeling in a waterfall or swift water disconects. After the first person is down usually everone else can be fireman belayed. Another way to stop on rappel is the leg wrap.

Discussion on the autoblock knots and application to canyoneering. Note I'm not trying to drive traffic to another forum. Just thought it was a good discussion to answer Felica's questions.

http://www.canyoneering.net/forums/showthread.php?t=93

Excellent information - Thank you!

Um, well, maybe not. Rich is very anti-autobloc, and those knot-tying sites do not discuss the subtleties such as:

1. Absolutely, not for use in waterfalls or moving water. Also, it will not "always" grab - if you flip upside down, it will reach to your rappel device and not grip. It is not a 100% foolproof technique (but it is pretty good).

2. A good tool to know, and use selectively. In order to continue "knowing" it, you will have to practice it.

3. The AutoBloc knot is very much preferred. Other knots (Kleimheist, prusik) once loaded are very, very difficult to release.

4. The SETUP is very important. The LENGTH is very important. The Autobloc must be short enough to NOT reach up to your rappel device. If it hits your rappel device, the device will "tend" the autobloc, or will get stuck in the rappel device.

5. The wraps will vary with your rope parameters. Each change in parameters will change how it performs. Size of rope, number of ropes, the wetness of the rope, the roughness of the rope, etc. Everything makes a difference.

6. It works well when the ropes don't change. Guiding, we always use canyon pro, and our autoblocs are a pretied length. We use three wraps on a single strand, and four wraps on a double strand. On a regular trip, using several different ropes, it will work on some, and not on others.

7. The SETUP: clip a carabiner to your leg loop, dominant side. clip the loop into the carabiner. Wrap the autobloc around the rope three or four times, and clip the end bight back into the same carabiner.

8. Is it right? - the length needs to be such that the knot grabs the rope if you let go of everything. Add more wraps? Can. It needs to be loose enough to not grab so much as to be difficult. It needs to be short enough that it does not reach to the belay device.

9. Modify the Setup: for many people, it will work better to extend your belay device a few inches, to keep it further from the autobloc. This is critical for children, youths and small women (small canyoneers). Usually helpful for men with a substantial pony keg (ie, table muscles, aka fat gut).

10. While rappeling: for the autobloc to grab, it must move up the rope to an upper position. In order to "go", the autobloc must be held down a few inches so that it does not grab. It is better to hold it in a fixed position and let the rope slide through it; than to let it grab, then release it, grab/release, grab/release. Each time it grabs, it tends to grab tighter, and be harder to release. The "other hand" is the brake hand, controlling the flow of the rope, and can be either above or below the autobloc. I often start using my right hand on the autobloc, and then switch to the right hand below and the left hand on the autobloc once I get going.

11. Some other tricks: CAN squeeze the rope through the autobloc, to gain a little more friction. CAN angle the rope through the autoblock to vary the amount of friction.

12. Autoblocs can be made from 6mm cord, tied in a loop. Tie the ends using a double fishermans with very short tails, tighten well, then toss in the laundry for a couple cycles. They tend to be slick and not very grabby to start. Once they fuzz up they work well. After repeated dunkings and dryings, they get shorter, which makes them grabbier. For 6mm cord, a good cut length is: (Tom to go find and fill in later).

13. At ZAC, we are now using sewn ones made by Sterling called Hollowblocs. I plan on carrying these in my store in the spring.

I'll try to write this up with pictures ... (don't hold your breath).

Tom

[Jaxx]

wow. Thanks Tom!

[trackrunner]

Also the effectiveness of these knots diminishes as the diameters of the two ropes approach each other.

A good rule I've heard for the cord diameter is take the diameter of rope in mm/2 add 1. So 8mm rope/2 +1 = 5mm cord. Tom can chime in on this if needed. EDIT: Now I'm second guessing myself is it only rope diameter/2 not +1?

Hey Tom what lengths of cord loop do you like to use? In the past I've either gotten too small to get enough wraps.

[Felicia]

Um, well, maybe not. Rich is very anti-autobloc, and those knot-tying sites do not discuss the subtleties such as:

...

I'll try to write this up with pictures ... (don't hold your breath).

Tom

Tom,

I'm sorry I'm turning your trip report into a knot lesson, but I'm really interested in knowing more - every trip report and every picture offers me an opportunity to learn something new.

I will admit that earlier this morning I did not know that an AutoBloc was a knot. I thought it was something else. Given the position that I'm coming from, all information is something. And right now, I have plenty of time to surf and gather. I will try to give it the weight that it deserves.

I will not hold my breath, but I look forward to a write up and pictures. In the meantime you and Trackrunner have given me a lot to process. Thank you.

[oldno7]

Um, well, maybe not. Rich is very anti-autobloc, and those knot-tying sites do not discuss the subtleties such as:

...

I'll try to write this up with pictures ... (don't hold your breath).

Tom

I will admit that earlier this morning I did not know that an AutoBloc was a knot.

And you still don't--technically it's a "hitch"
I read through Tom's stuff kinda fast, was there mention of extending your rappel device to keep from getting the AB from running through your rap device?
And as Shaun stated--any hitches used as a "rope grab" are not only diameter specific but weight specific also.
Test,test, test before using in a rappeling situation.
My only trouble with people using them is they become a "crutch" for otherwise knowing many ways to add friction on rappel. And they are not fail safe. (but nothing is in this sport)
Also an AB is counter-intuitive. ie. if you lose control of your rappel and begin to fall, your first instinct will be to grip the rope harder. This will make an AB not work as you slide to your death.

[oldno7]

p.s.
I've substituted AB for Auto-Bloc simply because that is were canyoneering is going. Nobody spells things out if they're "real" canyoneers. Just trying to blend in.

[ratagonia]

Um, well, maybe not.
I'll try to write this up with pictures ... (don't hold your breath).
Tom

I will admit that earlier this morning I did not know that an AutoBloc was a knot.

And you still don't--technically it's a "hitch"
I read through Tom's stuff kinda fast, was there mention of extending your rappel device to keep from getting the AB from running through your rap device?

Correct-a-mundo, kinda. A hitch is a special kind of knot that ties a rope to something stationary (the rappelling rope). However, knot terms are used incorrectly almost as much as they are used correctly. Many people refer to the technique as an "AB", the loop of cord as an "AB", or the knot as either an "AB" or something else. Just to be clear, when using an Autobloc (loop of cord) to do an Autobloc (rappel self-belay), be sure to use an Autobloc (the correct knot rather than, for instance, a prusik or a kleimheist.

Please allow me to quote for us from the "Book" (page 12):

'The word knot has three distinct meanings in common use. In its broadest sense, it applies to all complications in cordage, except accidental ones, such as snarls and kinks, and complications adapted for storage, such as coils, hanks, skeins, balls, etc.

'In its second sense it does not include bends, hitches, splices and sinnets, and in its third and narrowest sense the term applies only to a knov tied in a rope to prevent unreeving, to provide a handhold, or (in small material only) to prevent fraying.'

And as Shaun stated--any hitches used as a "rope grab" are not only diameter specific but weight specific also.
Test,test, test before using in a rappeling situation.
My only trouble with people using them is they become a "crutch" for otherwise knowing many ways to add friction on rappel. And they are not fail safe. (but nothing is in this sport)
Also an AB is counter-intuitive. ie. if you lose control of your rappel and begin to fall, your first instinct will be to grip the rope harder. This will make an AB not work as you slide to your death.

And this cannot be stated enough. I have seen many people hook up a rappel backup and spend a lot of time and energy doing so, and their setup most likely will not work. It is very tricky to get the correct combo of diameter, length and wraps that will consistently produce the desired performance - and then it will all change when the rope gets wet (or some other parameter changes).

On that last point, a properly set up AB will not allow you to STYD, no matter how hard you try. The gripping is rate-dependent, so if the rope is going through quickly, the AB WILL grab, no matter where your hands are. (Essentially, this is the definition of a properly setup AB (PSAB?), in which case...)

Tom

ps. the "Book" is of course, the Ashley Book of Knots.

[ratagonia]

Tom,

I'm sorry I'm turning your trip report into a knot lesson, but I'm really interested in knowing more - every trip report and every picture offers me an opportunity to learn something new.

Nothing could please me more!



T

[oldno7]

I won't argue only question that "all properly" set up AB will avoid a STYD incident? But---- I believe a too loosely wound AB(LWAB) may not ever grab a rope resulting in the STYD event?
So I guess your premise here--and knowing us canyoneer type are really smart(CTRS) is the "proper" set-up(PSE), which probably should not be internet taught(IT) will "usually" work?

[oldno7]

Also--I would not want to be the (CTD) who tests your theory of AB's always grab.

ahyeeeeeeeeeeeeeeeeeeeeeeeeee.........
oooohhhhh- sniiiiddddkkkeeeeeeeeeeeessssssssssssssssssssss

If you can show a link(SAL) to actual testing(AT) I will retract my "Your theory"(YT)

I'm sure glad no one writes like this in real life(RL) it's hard to read.(HTR)

[trackrunner]

I've been able to follow all the other AB etc. But STYD What does shop tell you drop have to do with an AB. Kurt I'd never expect you to be a shop-a-holic.

Also mods probably wise to split this thread into an autoblock/self belay thread.

[oldno7]

STYD=Slide To Your Death

[ratagonia]

I won't argue only question that "all properly" set up AB will avoid a STYD incident? But---- I believe a too loosely wound AB(LWAB) may not ever grab a rope resulting in the STYD event?
So I guess your premise here--and knowing us canyoneer type are really smart(CTRS) is the "proper" set-up(PSE), which probably should not be internet taught(IT) will "usually" work?

Ah, grasshopper, you miss the subtlety of the claim.

All PSE ABs prevent an STYD incident.

How do you tell if the AB is PSE? Easy - it prevents an STYD. If not, then it was not PSE.

This is a logical fallacy known as an IDENTITY. The fallacy is that there is actually any meaning in it. There is not, except maybe that Tom'd test for whether an AB is PSE is that it prevents a STYD.



Tom

[oldno7]

ahhh----- but the subtlety was indeed captured from your hand when I volunteered to not be the CTD for said experimentation of AB

on a complete sidenote---doing a "new to me canyon" around Leeds Friday,fwiw I will not be using an (AB) on the (NTMC)

By the way--Your OP TR sounds pretty fun.