Rapping (rappelling not the music dufus)

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Delhi Dog

Trad climber
Good Question...
Topic Author's Original Post - May 10, 2010 - 07:30am PT
Just to distance a bit from the tragic accident and create if needed a thread to address rap issues I'm starting this one, and no I don't think this is a RC.com thread (I never look at that anyway, so maybe it is...butt...).

A couple of things came up previously one being DR's reference to the EDK or European Death Knot and coining another term...you got one DR?

A question...If the two rope ends are tied together (assuming a skinny and fatty) would this not eliminate a failure and a big ride down(as described by the knot sliding through the ring)? Several mention having done this over the years (including me).
If the rap was less than a rope length than maybe not, but in one greater?

I would assume at a solid stance (tied in and then the skinny rope could then be untied and pulled)...or would it just be a wicked shredding ride?



Here is that picture again from Petzl and how it should be done (excluding the ends tied)

Here are several links that were shared and maybe worth looking at;
http://www.canyonwiki.com/wiki/index.php/'biner_block

Rapping 101
http://www.innergycoaching.com/goclimb511/gc-101.php

more...?

Cheers,
DD


Doug Robinson

Trad climber
Santa Cruz
May 10, 2010 - 08:45am PT
Overhand Knot is good.

Instantly like it for being so ordinary, understandable.

Double Overhand is accurate, but with a slight confusion. Like we don't say double figure eight.

Rap Knot possibly?

I like the way it slides over the rock pulling down, the way it resists snagging. I just never converted to using it. Mostly because of the name. Just didn't want that in my head as I checked my prussic and started down.

It's bad enough doing the second most dangerous thing in climbing (the sharp end in #1) without a morbid name hovering around every time you set one up.

And by the way, use a prussic. Every time. Yes, YOU.

Half of rap accidents are the anchor. The other half are something happening to you while rapping. Like getting hit on the head by a rock.

Use a prussic, above your friction device. Not the idiotic autobloc below it, where the rope can run through your safety a moment before you slide off the end.
Edge

Trad climber
New Durham, NH
May 10, 2010 - 08:50am PT
A couple of things came up previously one being DR's reference to the EDK or European Death Knot and coining another term...you got one DR?

I have long advocated that the term for an overhand knot used to join two ropes for the purpose of rappelling should be Americanized to make it more popular.

How about the American Happy, Fun Useful Climbing Knot, It's Terrific.

Or simply by the acronym "Ah, f*#k it"

Whatever you call it, you just need to make sure that the tails are long enough so if the knot rolls, as it often will, there is still plenty of backup tail. I shoot for 12" minimum.

tradmanclimbs

Ice climber
Pomfert VT
May 10, 2010 - 09:06am PT
DR, I know you have been arround a long time and all but the autoblock below the rap device is 100% more efective, usefull and safer than the idiotic prusic above the rap device ;)
tradmanclimbs

Ice climber
Pomfert VT
May 10, 2010 - 09:29am PT
Edge, If the EKD rolled often I certainly would NOT use it. I have used the EDK exclusivly for about 6 years and it has never rolled once or even given the hint of rolling. I do use the long tails. I have rolled the EDK with my F150 but that is an entierly different situation than rappeling. If you plan on rapping with an F150 or anything larger than a mini cooper I suggest useing an inline 8

For most other normal climbing Rappels the EDK with long tails is good.
Doug Robinson

Trad climber
Santa Cruz
May 10, 2010 - 09:46am PT
I use 5 mm Spectra cord (not kevlar), about 5.5 feet long, tied with a triple fisherman knot (= proven to work in slipperier cord). That makes a standard length runner to wear over my shoulder with all the rest of my runners.

Prussic tied above rap device. Snug it onto the rap line so it'll be sure to bite if needed. Cradle it in my uphill hand to slide it along.

It's tempting to tie a prussic loop out of accessory cord. Much cheaper. But also way weaker. Like having a "not for climbing" toy carabiner on your chalk bag, it risks drifting into the belay chain.

I use my spectra runners a lot for tieing off small knobs where nothing else will grip. Usually carry 2-3 of them as runners.

When I teach a newbie to rap, I always give him/her a prussic cord. Might be their first piece of gear. No excuse after that for overlooking the prussic backup.

How can an autobloc be "100% effective" when it is so easy for the rope ends to slide right through, rendering it useless?

Besides it kinks the rope mercilessly, which is not just annoying but dangerous, starting with being distracting.
MisterE

Social climber
Across Town From Easy Street
May 10, 2010 - 10:31am PT
I have used the EDK exclusively for 20+ years on similar diameter ropes. Never had any slipping problems, except on very different sized ropes (10 mm & 8mm), where I use the double fishermans.

I agree that it snags way less than either the in-line 8 or the double fisherman's.

The only other issue I have heard about with the "overhand knot" is slippage in cold and/or wet conditions (which I have never experienced, but have had friends report).

If I am really worried (for whatever reason) and there are no snag issues, I will tie back-up knots in the tails.

My $0.02
MisterE

Social climber
Across Town From Easy Street
May 10, 2010 - 10:37am PT
Euro Death Knot
tradmanclimbs

Ice climber
Pomfert VT
May 10, 2010 - 10:45am PT
DR, I am also an old fart and I fought the new style backup tooth and nail. Finally I saw the light and it really does work better.

The prusic above the knott is a bitch to unstick when it locks up. If its loose enough for smooth rapelling its too loose to actually catch you if you mess up. Doubtfull that either method is going to save you if you rap off the ends of the rope unless its so tight that you can only rap by force feeding the rope through the prusic.

The autoblock below the device requires verry little friction to lock up and is super easy to get moveing again. The prusic above the device requires lots of force to lock up and then is under full body weight keeping it welded shut untill you figuer out how to unweight that section of the rope.

I can zip allong free as a bird, lock up whenever I wish, have both hands free to work,trundel,clean etc and then get going again effortlessly.

With the prusic above the Rap device it might possibly save you if you rapped off the ends of your rope but only if it was pretty tight to start with. If you start with it tight enough to lock in an emergency with only 2ft of tails to work with then it will get tighter with every move untill you will be stuck and have to loosen it up and restart.

In theory I would agree that the prusic has a better chance than the auto block of saveing you if you rap off the ends of the rope but in real life yer still gonna die.. those rope ends are not going to both slide through at the same time and that sneaky short one is still gonna slip through before you have a chance to lock up that PAINITA prusic that you just loosened up ..
Doug Robinson

Trad climber
Santa Cruz
May 10, 2010 - 11:16am PT
Tradman, I know you too are old as dirt and I value your opinion, but I respectfully disagree.

I snug my prussic, not tighten. Like stirred, not shaken maybe. It's easy to demonstrate that when, as you say, a loose one doesn't grab. Snug it just right, and it will tighten within an inch when needed.

I think the image of sailing down a rap easy as you please is a little too carefree. Like the "be all you can be" launching out of a chopper. Maybe I would too if someone was shooting at me, but it tells you something that the Army manual requires retiring a rope after just 10 hours of that abuse. Since the taxpayers aren't buying me new cord, I can't afford that.

But the point is more like carefree is not respectful enough of the true danger of rapping.

So a bit of drag on the prussic knot is a good thing. Helps remind you to keep moving it with you instead of letting it bind up which, yes, is a hassle. I would rather teach folks ways to loosen their stuck knot, though, than clean them up all splattered below.
luquitos

Trad climber
santa cruz, ca
May 10, 2010 - 11:26am PT
so what's the best knot to use when tying two ropes of very different diameters together, say 10mm and 6mm?
tradmanclimbs

Ice climber
Pomfert VT
May 10, 2010 - 11:27am PT
I don't take it that care free. The auto bloc has saved my butt a few times. It even works on iced up ropes. I used the prusic set up for many years and after much resistance/dragging my feet found that the autoblock is INMOP a better system for most aplications.
Chiloe

Trad climber
Lee, NH
May 10, 2010 - 11:31am PT
Personally, I like the EDK name and knot. Use them all the time.
Perhaps the ironic name helps remind us to tie the knot well, when we do.
survival

Big Wall climber
A Token of My Extreme
May 10, 2010 - 11:38am PT
But the point is more like carefree is not respectful enough of the true danger of rapping.

That's more my mentality.

I can understand "light and fast" for some people on routes where every ounce counts. But even on long enduro-days, we generally weren't too weak to carry two fat ropes.

Maybe I'm TOO old school, but we're talking life and death here. I am still a rookie, only been climbing walls and long trad routes for 35 years, but in all those years, I have had VERY FEW snagging incidents. Many of those stuck ropes had nothing to do with the knot anyway. I have never liked half-a-knot.

For the average guy, on most outings, I just don't understand why two fat ropes, BOTH going through the device is too much trouble. The majority of everything I've climbed has been done that way. I'm still here.
cleo

Social climber
Berkeley, CA
May 10, 2010 - 11:39am PT
Enjoying the exchange between DR and tradman!

FWIW, I've tried both, and like it above the knot, provided one is *very* careful not to tie it out of reach (this is easier to do that most people realize). I've had people tell me that above was wrong, and after lots of careful consideration and futzing with ropes, decided that, no, it is okay. Glad to hear somebody agrees with me (DR)!

Good advice to always use a prussik. Or... have somebody give you a fireman's belay.
tradmanclimbs

Ice climber
Pomfert VT
May 10, 2010 - 11:46am PT
When I started in the early eightys in the east we only used one fat rope. never even thought of backing off of stuff and we always topped out and hiked off. First climbing trip out west,86 we brought 2 11mm ropes. that is a heck of a load to carry but we were young and strong so it did not bother us. These days I mostly do multi pitch with doubble 8.6mm ropes and that is pleanty light enogh for most situations.. The EDK is pleanty strong and safe when proplerly used. you can't blame this last accident on the knott. Seems like the whole tagline system is a bit sketch.
cleo

Social climber
Berkeley, CA
May 10, 2010 - 11:47am PT
Lots of discussion about slippage w/ figure 8s and friction biners and skinny ropes in the other threadv...

I'm a little confused about what, exactly, it being discussed, but can add this: with an ATC and a single line, it is possible to use *both* ATC holes to add lots of friction with that single line. And that made all the difference.

Seamstress

Trad climber
Yacolt, WA
May 10, 2010 - 11:51am PT
I have been using the autobloc for 15 years, and it works beautifully. I am short, and have fussed with the prussic above. It has jammed, and it can get out of reach. For the tall folks, that isn't a big deal.

I am most concerned about losing control of the rope - negotiating a bad lip, falling objects that disable you. I like a back-up that passes the whistle test. The autobloc below does that.

I am not worried about rapping off the ends - too cautious to not be looking at that. I have ended up short of the next ledge or anchor on a few occasions. This is another curse for being smaller and lighter. My partners seem to be able to stretch that rope a little farther. THere is always a way to deal with that with a foot of rope still below the device.

Edit: I will tie the ends together generally. Hate hitching to that next anchor with slings/cordeltte, untying that knot, and sliding off the end. Always make the heavy guy go first. It amazes me how many routes and rap lines are so far apart. Remember when 50 meters was a long rope, then 60 meters was long, but wait 70 is the new standard...and 80's aren't far behind!!
Mighty Hiker

climber
Vancouver, B.C.
May 10, 2010 - 11:52am PT
An interesting discussion. Rappelling is one situation where simplicity and speed aren't necessarily synonymous with safety.

Spelt Prusik, though - http://en.wikipedia.org/wiki/Karl_Prusik
Delhi Dog

Trad climber
Good Question...
Topic Author's Reply - May 10, 2010 - 11:59am PT
One thing that strikes me is that as climbers we get into certain routines that work.

Whether it's a prusik or the autoblock for example, that routine works for us. When we deviate from that routine that is when the sh*t can (potentially) hit the fan...(to paraphrase Calos Castaneda via Don Juan)'certain things matter to us in our lives because they are important' and 'we learn to think about everything, and then we train our eyes to look as we think about the things we look at...'

He was referring to moving beyond this, but somehow it seems to me that in cases of (potential once again) life and death outcomes we always need to be very deliberate, very methodical. Train ourselves to see the ordinary as if for the first time-every time.
Self evident, maybe, in practice...?

Good discussion all.

DD

edit:
seamstress...why knott:-) tie the ends together whenever possible? You have everything to gain and a lot to lose...
D'Wolf

climber
May 10, 2010 - 12:00pm PT
First, it's an overhand knot; "EDK" is the "other" name. It concerns me a bit that there are climbers, er, uh, "people climbing" that don't know their standard knots (or so it appears). Learn them (and their appropriate uses) before you get yourself killed.

As a counter-balance to those proponents of the overhand knot in joining two ropes, I've never done it in nearly 20 years of climbing and I've never had any of the problems the overhand is claimed to prevent. I tie my ropes together with a double fisherman's. Overkill? Maybe. Safer than an overhand? Undeniably.

Autoblock, Prussik; does it REALLY matter? Learn both, pick one and use it. Tie knots in the ends of the rope and rapping off the ends isn't an issue regardless of the backup system used. I might mention, however, that Spectra may be stronger than nylon, but it is slicker and has a lower melting point - not the best choice for a Prussik or Autoblock as it may not grab immediately, could slide far enough (and long enough) to burn through and snap when it does finally grab. 6mm Perlon is plenty strong for this use and potentially safer.

Progress on ST: finally we're debating the merits of two safe climbing practices rather than comparing safe and unsafe.

Cheers,
Thom
Delhi Dog

Trad climber
Good Question...
Topic Author's Reply - May 10, 2010 - 12:07pm PT
Thom,
just saw this "Progress on ST: finally we're debating the merits of two safe climbing practices rather than comparing safe and unsafe."

My edit above (to seamstress) was rhetorical not meant to debate.

Cheers,
DD
D'Wolf

climber
May 10, 2010 - 12:12pm PT
DD,

Posted before seeing your edit; not directed at you or anyone else. Perhaps "debating" should be "discussing". Just nice to see the pros and cons of good systems being talked about, enabling people to learn something and make safe, informed decisions.

Cheers,
Thom
tradmanclimbs

Ice climber
Pomfert VT
May 10, 2010 - 12:19pm PT
Good luck with your doubble fishermans ice climbing... we might have to start calling you good ol 3 fingers. Like to see you untie a doubble fishermans without takeing off yer gloves on frozen ropes that have been weighted by fat ice climbers w/ full winter packs...
Reilly

Mountain climber
The Other Monrovia- CA
May 10, 2010 - 12:34pm PT
DR,
I learned the prusik rap backup on a certain Mr Beckey's advice. He apparently never had a serious rappel accident either. Also upon his advice I almost always (on 'serious' climbs) carried a couple of extra 6mm Prusik loops in my pocket. Never needed 'em but that is what insurance is for, right?

I learned another thing from Mr B which saved my life a number of times.
I'm trying to overcome writer's block to share it.
ontheedgeandscaredtodeath

Trad climber
San Francisco, Ca
May 10, 2010 - 12:58pm PT
I've always used a double fisherman's. Have I been cheating death all these years?? Don't ice climb (thank gawd) so untying it is not an issue.

D'Wolf

climber
May 10, 2010 - 01:09pm PT
Tradman,

Ya got me there, can't argue. Not an ice climber so I'll defer on that one... Untying a wet, frozen fisherman's with wet, frozen hands? Yeah, you're right, good luck.

A good case for my original post: learn the various knots and their appropriate uses. Double fisherman's wouldn't be appropriate in that situation; perhaps the overhand would be better.

In all fairness, I'm not an opponent of the overhand knot; I just haven't used it for joining ropes together for rapping. I have used it for adjusting cordelette length, where I can watch it and where I have multiple points of tie-in so a failure of the knot wouldn't be catastrophic.

Cheers,
Thom
David Wilson

climber
CA
May 10, 2010 - 01:13pm PT
I've rapped for years using a 7mm and an 11mm with an ATC and just being careful to grip the ropes a bit to control slippage ( knott in end too ) . I guess if you wanted to use a really skinny rope, like a 5mm, the single line method would be warranted.

What about the in line 8 for joining dissimilar ropes? I've used that a lot as well as the double fisherman's.
tradmanclimbs

Ice climber
Pomfert VT
May 10, 2010 - 01:13pm PT
soak your ropes in water, weight em with at least 250lbs = fat ice climber with boots, crampons, 3 axes,16 screws, half a rock rack w pins etc, 8 screamers,thermos of hot coco, extra clothes, 3 pairs of gloves (2 of which have been soaked through and frozen stiff) etc,etc. throw the whole mess in the walkin freezer and turn the fan up to 60mph with gusts to 100. Now try untying the doubble fishermans in the dark with your last good pair of gloves on.

The EDK is so easy to tie and untie w/ gloves even when frozen solid that it is a no brainer as best choice for Alpine and ice. If you are going to trust your life to it in the winter then there is no point is useing something stronger in the summer. Either you trust it or you don't.
I trust it so that is the knott I use.
D'Wolf

climber
May 10, 2010 - 01:34pm PT
Tradman,

Point well taken; however, if I found myself in a situation where I was forced to do a single-line rappel on a 60m piece of 6mm cord to save my life, I'd do it. But, it would scare the bejesus out of me and even if I made it, I wouldn't repeat it on a routine basis.

People learn to trust and rely on unsafe practices simply because the odds of a bad outcome are low. Something might initially scare them, but over time they become desensitised to the danger and forget about it. Then one day something happens. I see this in my daily work environment where coworkers have been killed. I generally don't trust the overhand. It is strong enough, and used by a lot of people, but there are safer options more often than not (IMO), albeit with some inconvenience. On ice, frozen, in the dark, etc? Yeah, if I had to resort to the overhand, I would; but, if I don't HAVE to use it, I won't. A little inconvenience is okay.

Again, I do use the overhand, but only where I can actually monitor the knot and its failure wouldn't be catastrophic. Not an indictment of you or your methods.

Cheers,
Thom

Chiloe

Trad climber
Lee, NH
May 10, 2010 - 01:34pm PT
Double ropes sure are nice to have on ice climbs, where a clumsy swing or kick could slice one right to the core.

On dry rock, if I know two ropes are needed to descend I like doubles a lot more than one single and a tag line. That combo might cost a pound but gives a simpler rap set ups and a plan B if one gets stuck or cut.

As for the tie-knots-in-the-end theory, there are times when that's a bad idea.
HighTraverse

Trad climber
Bay Area
May 10, 2010 - 01:36pm PT
A few thoughts and questions from an Old F*&T

cleo: how do you get a single rope through both ATC holes?

I'm split on the prusik/autoblock question.
I use an ATC for rappelling and belaying. Rapping on two ropes, it will slow me almost to a stop if I let go and either the prusik or autoblock is fine.

Everyone should know how to rig a carabiner brake and carry enough ovals/Ds to make one (4 plus your locker). Wiregates/pearshapes aren't safe for this.
Know the Dulfersitz, I've had to use it a couple of times.

A prusik can get out of reach. Long ago a young lad died at the Pinnacles when his prusik slipped out of his reach on an overhang and he suffocated (with no leg loops). Many of us have climbed before leg loops were de rigeur.

I don't always use a backup. I remain to be convinced that it's an absolute necessity.
I do use a backup when: there's an overhang, the rope is wet or icy, I'm not CERTAIN the ends are on the ground, it's dark, I'm tired, I've got a big pack, etc. e.g. whenever I'm not 100% sure about the situation.

I ALWAYS tie a separate knot in the end of each rope rather than tie them together. This reduces the chance of snags when throwing the rope, allows one end to be tossed while the other is being sorted (with a clove hitch at the anchor so you don't lose the whole bloody thing), and makes it easier to clear snags either before you start down or when you find the mess on your way.

What is the best knot to use in the end?
Is there a reason tying the ends together is better?

I've never had a problem with an 8.8 and 11mm combo. Either double fisherman's or EDK are easy to tie and hold.
I know from climbing and ocean sailing experience that a double fisherman's will hold with two significantly different size and even material ropes.
Don't know about the EDK with different size ropes.

What's a double EDK? I can think of two possibilities: either 2 of them tied one after the other, or put a bight in the two ropes and then tie an EDK in the bight.

With two "fat" ropes (and I include the 8.8) I never worry about which one is through the anchor. A great convenience on multipitch rappels as you can thread and start deploying the rope before the last rap has been completely pulled. And you've always got the rope through one rapp anchor.

Yes, the double fisherman's is a real pain when wet or icy!
The EDK can be tied/untied in half the time. Useful when on mixed terrain.

I can't remember the last time I rapped on a single rope when free climbing. Can't imagine why I would under normal circumstances.

I often back up the rap anchor until the last climber descends, then he/she can remove the backup (or leave it in place if necessary).

Let's just call it Overhand Knot, then even a Boy/Girl Scout will know how to tie it as long as they know to do the long tails.
Or we can keep calling it EDK and before long its derivation will have submerged in the heap of historical (hysterical) trivia.

I've climbed a bit with Mr B and was impressed by two things:
1: NEVER hurry a rappel, even if the scheiss is hitting the fan. If all Hell is breaking loose you need to be MORE careful.
2: Much the same for a belay anchor. Efficient, neat and safe don't need to be hurried.

And with all my care with rapping I very nearly stepped off once without putting the ropes through the biner on my harness!! It would have absolutely been the end of me. I saw it when I did my own double check just before I "weighted" the rope.

DOUBLE CHECK everything EVERY time and always check your buddy. If your partner rigged the rap and you don't like it, say so!!
The life you save may be hers.
HighTraverse

Trad climber
Bay Area
May 10, 2010 - 01:45pm PT
Excellent link from the other thread.
I post it here because I like DelhiDog's idea to make this a separate thread from Brian's death.
http://web3.bdel.com/scene/beta/qc_kp_archive.php#123008


And speaking of confusing nomenclature:
There are two meanings now of "autoblock"
One is an autoblock belay device such as a GriGri or an ATC Guide used in autoblock mode.

There's also the autoblock knot which is used much as a prusik, is tied differently and acts in a different location in the belay chain.

I presume DR and others were meaning the autoblock knot, as was I.
rectorsquid

climber
Lake Tahoe
May 10, 2010 - 01:46pm PT
Everyone should know how to rig a carabiner brake and carry enough ovals/Ds to make one (4 plus your locker).

You could use a munterhitch. Two ropes? Use one munterhitche on each of two carabiners. Offset one from carabiner the other with a sling. Any thoughts? Two of any carabiner and a sling instead of four ovals?

Just thinking out loud here.

Dave
cleo

Social climber
Berkeley, CA
May 10, 2010 - 01:50pm PT
I will take a picture of an single (skinny) rope ATC using both holes, but it will be later, tonight.



I learned this from a friend while rapping for Lost Arrow Spire, when I balked at using a skinny rope and my ATC. It was much better (for control), but I've never seen any discussion of it elsewhere, so I'm curious as to the implications of it.

Ken M

Mountain climber
Los Angeles, Ca
May 10, 2010 - 02:02pm PT
I find myself in total disagreement with the concept of using a prussik ABOVE the belay device, as a technique that will save you if your ends go through the belay device. It won't work.

Here's why: The concept that is involved requires you to hold onto the knot so that it will slip. Should you feel the ends of the rope slide through your bottom hand, to allow the Prussik to bite, you must release the knot. Get that: you feel the rope ends go through your hand, and you must instantaneously let go of EVERYTHING that you are holding onto! This defies all human instinct, which is to grab onto something, anything! When you instinctively grab the prussik knot tighter, it opens and slides faster, hastening your demise.

I remember a study done 10 years or so ago, that I don't seem to be able to find, in which they took a bunch of guides, and hooked them up with the prussik above, then unexpectedly dropped them such that they needed to engage the pussik to stop.(with a backup system). All off them rode the knot to the ground (the backup system caught them).

Or in other words, it failed virtually 100% of the time, under ideal conditions, with skilled climbers.

It is inescapable human reaction to grab instinctively when you fall. This system requires you to let go. I don't think that there are many who can do that.

The system with the friction knot below the system works if you either let it go, OR if you hold it tight, not true for the one above.

This is a nice paper that discusses the general topic of rappel safety in depth:
http://www.rescuedynamics.ca/articles/pdfs/rappel.pdf
wbw

climber
'cross the great divide
May 10, 2010 - 02:38pm PT
Maybe I'm missing something, but what is wrong with joining two ropes with the figure eight knot, where the second rope is followed through the 8, and coming out of the knot at the place where the first rope goes into the knot. (figure 8 follow thru). If you measure the diameter of the knot, it is not at all significantly larger in diameter than the EDK. I know the EDK is recommended by rope manufacturers, and guides seem to love them, but I just have never felt comfortable with it. I've also never found the figure 8 to be prone to snagging. Prior to pulling the ropes, I give both ropes a big shake to try to get them off the surface of the rock near the anchor. The figure 8 can be untied with gloves on, in the ice climbing scenario mentioned above.

I also do not like the prusik as a back up for rappeling. If you're worried about rapping off the ends of the ropes, tie a knot into each end, independent of each other. The autoblock works well when tied above the friction device, although it does tend to twist the ropes.

Finally, it is important to remember that every different way of doing things has benefits and disadvantages. Sometimes I think the emphasis on doing everything light and fast tends to make us believe that everyone should be climbing as if doing a single push on El Cap, or a big alpine route. Some techniques that lend themselves to speed, may cost in terms of overall safety. On a big alpine route, this may be justifiable because it is often the case that just being on the route longer is more dangerous.
Auto-X Fil

Mountain climber
May 10, 2010 - 03:00pm PT
As the terrible accident that brought up this discussion occured using the same basic system I use, I re-evaluated how I rap and am still content.

I always climb on my partner's doubles when there are three of us. When I go with just one other person we typically use a single and a tag line. I am leaning towards buying some doubles at some point, but there are some advantages to leading on a single (less cluster at belays, weight, cost). So for now I'll continue to do so.

When I rappel I use quick-links. I buy cheap hardware store items in a smaller size and use two for redundancy. When possible I mix and match sources in case there was a bad batch, but an inspection is usually suffient to put me at ease. These quick-links are not too heavy to carry, mean I don't have to rely on manky fixed rings, and the small opening makes it very hard for any knot to slide through.

My single is a 10.2mm. I tie a 6mm tagline to it with a flat double overhand. That is, an EDK with an extra pass through the loop. It looks like one half of a double-fishermans made with two strands. The advantages of this knot are lack of the potential inversion that shakes the confidence of many who would use the EDK if it wasn't for Moyer's tests, the same flat-knot layout for ease of pulling over edges, and a bulky, round knot that won't pull through rings and also won't slip into cracks and cam into place like a less-round knot can.

It is slightly harder to untie than a single flat overhand, but I manage with ice climbing gloves just fine. It's much easier than a double fisherman's or even a fig-8 follow-through. The mis-match in rope sizes seems to help untying.

When snagging is not a big issue (snow/ice slopes, smoothish rock), I use a locker. I use Craig Connally's method, in which you use a double-fisherman's slip knot to attach each rope to the carabiner (on opposite ends), and then clip the biner back around the rappel strand. It's much cleaner and less likely to snag than the versions in the other thread, while still providing a backup for the knot.

When snagging is an issue, I use the flat double overhand, my skinny quick links, fresh webbing if needed, and then hook up my ATC Guide. I get significant friction on the 6mm with the ATC Guide, which takes some of the load off the knot. It also prevents the thin line from blowing around in the wind and tangling.

I then attach an autoblock backup. I use backup knots in both rope ends (double overhands with decent tails), which are a MUCH better alternative to a friction knot above the device. Hanging on an ATC and autoblock jammed up with two double fisherman isn't fun, but it's bomber. Having your un-knotted rope ends slip through the ATC and hopefully catch a prusik sounds terrifying.

Skipping the tag line approach is certainly a valid one if you are concerned. When you look at the size of the knot I use, the way it deforms under load, and the size of the quick-links, it's obvious it'll hold.

As far as the EDK - when using doubles I often use a fig-8 followthrough with backups. But if the rope might snag, I use a flat knot. If you are aiding and have extra ropes, feel free to risk one. But I only ever have one rope (or pair of doubles), and getting stuck 4 pitches up isn't cool. Flat knots work, use my variation if you're scared of the rolling EDK.

Keep using not-flat-knots if you want - but I've had ropes stick, and it's very f*cking scary. Way scarier than a knot that you know works, but has a scary name.
Mighty Hiker

climber
Vancouver, B.C.
May 10, 2010 - 03:03pm PT
I've always liked the redundancy and control that comes with using a carabiner brake (2 x 2 x 2, or 2 x 2 x 3 when I'm scared or it's steep) and the double figure eight reversed, with decent tails. And I have ovals for doing it when needed, though usually now I use my ATC or equivalent.

The idea of lugging a gri-gri style belay device around for real climbing, let alone rappelling, isn't very inspiring. A second rope for rappelling, or double ropes, has many advantages, especially if the second rope is good enough for leading in a pinch.

A figure eight knot for joining ropes of unequal diameter, and general security, can't be beat. Whatever the theory, they just look right.

I believe that one of the supposed advantages of the EDK, aka double overhand, is that it may be less likely to snag than say a double fisherperson's knot or a double figure eight reversed. Although with the EDK, you pretty much have to have long tails, or a backup knot, whereas those aren't compulsory with the other knots. So the combination may be just as snag-prone. If you combine the EDK with an autoblock made of another knot - probably a double figure eight with a bight, plus a locking carabiner - the total seems very snag-prone setup, even without adding any knots that might get tied at the rope ends.

This may be a specialized technique that has become widely used, perhaps without thorough consideration. Redundancy is so critical - as with the elaborate belays you sometimes see climbers construct, where they then tie into or toprope through a single locking carabiner. Unclear on the concept.
Chiloe

Trad climber
Lee, NH
May 10, 2010 - 03:08pm PT
As a fogey I learned to use a Prusik above the brake, and made countless raps without
serious incident that way. I never figured it would catch me if I let the rope slide through,
but it added options for some other scenarios.

But even fogies can go with the times. Lately I've seen some advantages to an autoblock
below the device, when I'm nervous about something.

It's not at all because either one would save me if I rapped off the end. But they offer
an option (especially the autoblock below) for stopping if complications arise suddenly,
as they will.

wbw

climber
'cross the great divide
May 10, 2010 - 03:13pm PT
Auto-x, have you ever measured the largest diameter of the figure 8 follow thru rappel knot, and compared it to the EDK. The name doesn't bother me; I just have never thought that the advertised advantages, such as doesn't snag on the pull as much as other knots, are as significant as people say.

I don't generally back up the figure 8 when I use it for rappeling, to keep the bulk of the knot as low as possible. Maybe the main reason I like it is that I have used it as my system for rappeling for so many years, in many different rappeling situations, without having any difficulty.
Gene

Social climber
May 10, 2010 - 03:17pm PT
Any opinions/consensus on the knot(s) to tie in the bottom ends of the rap ropes? Tie both ropes together with a huge knot? Knots separately in each strand? What knot to use? I typically tie the bottom strands together with a figure 8 on a bight.
snaps10

Mountain climber
Visalia, CA
May 10, 2010 - 03:17pm PT
Personally, I weight and unweight my prussik, on rappel, hundreds of times a year. I don't have a problem getting them undone, never have. I use 6mm for my prussiks for personal climbing and 8mm for rescue. Always tandems for rescue if I may be adding a load to my own body weight. Always triple wrapped.
I rap with my prussik above the rack or device, always. My thought process is:
I can keep the prussik at whatever distance I want away from my body, and it will grab without jerking me by just letting go.
If I need to weight the prussik, I don't have to jam up my rap device to get it to grab. Consequently, I don't have to unjam my rap device when I want to continue on my rappel.
Someone mentioned the whistle test. I challenge them to put on their autoblock below the device, start to wrap, then whistle and let go without wetting their pants. With a prussik above it is no big deal.

I tie barrels in the bottom, and never tie them together, it can be a twisted mess sometimes if they're tied together and you're using two different diameter ropes.
Mighty Hiker

climber
Vancouver, B.C.
May 10, 2010 - 03:29pm PT
If you want to be certain not to rappel off the ends of ropes, tie them together in a double figure eight. Either that, or clip a piece of gear to the bottom of each rope - then there's no chance of a rope slipping through your rappel setup.

Several accidents, including I believe Jim Madsen's on El Capitan in 1968, showed that knots can feed through carabiner brakes, at least.

Chiloe's carabiner brake setup could use a second cross-carabiner.
Chiloe

Trad climber
Lee, NH
May 10, 2010 - 03:45pm PT
Chiloe's carabiner brake setup could use a second cross-carabiner.

Agreed, but I didn't have a fourth oval. I would have used a munter instead, if I
had a large locker along. What you see there was rigged unexpectedly with gear
that happened to be at hand. It worked.
Gene

Social climber
May 10, 2010 - 03:50pm PT
Knott to pick nits, but

Agreed, but I didn't have a fourth oval.

Wouldn't any biner work as the cross piece?

g
tradmanclimbs

Ice climber
Pomfert VT
May 10, 2010 - 04:13pm PT
Pate, any multi pitch I use doubbles. Any single pitch I use singles. there are exceptions to every rule or method though. Long single pitch ice climbs its back to the doubbles. Multi pitch spurt climbs with anchors every 30m I use a single. Long single pitch desert cracks are better with a single and a tag off the back of the harness. 2 ropes in the crack get in the way of the feet. Got to be flexable and use diferent systems for diferent aplications. Just make sure you have em all wired.

BTW when I use the tag line its one of my 8.6mm doubble ropes and I rap both lines, no tricks.
Gary

climber
Desolation Basin, Calif.
May 10, 2010 - 04:44pm PT
In the accident thread coz posted:
Futhermore, jamming knots and all this trick stuff is killing people use the kiss system.

Yes! Keep it simple.
Keep it simple and safe.
ec

climber
ca
May 10, 2010 - 04:52pm PT
use 5 mm Spectra cord (not kevlar), about 5.5 feet long, tied with a triple fisherman knot[...It's tempting to tie a prussic loop out of accessory cord. Much cheaper. But also way weaker.
- DR

Doug is strength the issue in a prussik? Spectra has a very low melting point. I never went there because of it...however I did some other pretty stupid things with it...like a single fixed line to jug on...
Spectra has several difficult issues. The melting point is very low, 147 °C or 297 °F, not much warmer than boiling water.

from: http://www.caves.org/section/vertical/nh/49/cthsc/cthsc.html

 ec
Japhy

Mountain climber
Kathmandu, Nepal
May 10, 2010 - 04:53pm PT
Hi all,

I've posted a response with my analysis of the accident on this thread:

http://www.supertopo.com/climbing/thread.php?topic_id=1164065&msg=1165822#msg1165822

I'm not sure if I should have posted it on this one, so please let me know.

Thanks,
Japhy
Chiloe

Trad climber
Lee, NH
May 10, 2010 - 04:55pm PT
Wouldn't any biner work as the cross piece?

Nope, not the ones I had. Tried 'em.
Brian in SLC

Social climber
Salt Lake City, UT
May 10, 2010 - 05:09pm PT
From the crossposted analysis:

Pull cords of that diameter have a much lower melting point.

Melting point of a fiber doesn't really change per se with the diameter of cord it's woven into.

Changing the amount of friction might generate more heat, related to diameter methinks. But, not melting point.

Anyhoo...sad deal.

I use a pull cord and rappel from a Gri Gri quite often. Also use a pull cord and single dynamic rope with an ATC too, but, I usually rappel them together. Most often from a "knot block". Sometimes from a figure eight on a bite to which sometimes I attach a locking biner and clip it back through. Just depends on the chanee I think the ropes will hang up or not.

Always try to jam the knot against a link/ring that I know won't allow the knot to slip through. Did have one pop through in the Tetons (from Guides Wall) and was glad I was rappelling both the pull cord and the lead line. Just adjusted the friction on the cords to keep the smaller diameter pull cord from creeping.

Take care out there...

-Brian in SLC
kev

climber
A pile of dirt.
May 10, 2010 - 05:33pm PT
So unless you're trying to go ultra light then why not take 2 lines (or a single 70 or 80)?

I have a 8.9, and a 9.4 lead lines and an 8 mil tag line. If the route requires two lines I take the 8 mil plus one of the lead lines. Not too much weight here. Just seems easy and you've got the flexibility of two ropes (even if one is static) in a pinch.

kev
mucci

Trad climber
The pitch of Bagalaar above you
May 10, 2010 - 06:09pm PT
I just don't see the advantage in using a 6 or 7mm pull cord rather than a 8 or 8.5 1/2 rope?

How much wight are we talking here?

You can lead on a 1/2 rope in a pinch.
Lighter than a single rope.

Can someone explain to me how using this method with the backup biner, a better way to avoid snags when pulling?

There is so much shite going on with that EDK/pull cord method, 2 or 3 knotts, and a biner that all have to come down when pulling.

I guarantee that I can rig a rappel with a figure 8, or fisherman's in the SAME amount time it takes to set this "LIGHT and FAST" rappel.

Please enlighten me.

Mucci

August West

Trad climber
Where the wind blows strange
May 10, 2010 - 06:21pm PT
There is a pretty big difference between 7mm and 6mm in both bulk and weight. I can treat a 7mm as a rope and get it to grip the rap device, not so a 6mm.

The main advantage that I see for the 6mm, is you can coil it up and stick it in a summit pack or fannypack. Cannot really do that with fatter ropes. So you either trail it, with all those hassles, or have a coil on your back (possible in addition to summit pack).

I played around with a 6mm (and a 5.5mm) tag line. I found it not worth the trouble. At best, take when you don't expect to use it (planning on walking off, but don't summit).

I never liked the biner backup because of fear of it getting caught when pulling the ropes. As an alternative, we would set up the rope/pull line through the anchor but then tie the main rope off straight to the anchor, for the first one down to rap a single line (first down also comes down with the pull line). Once the first down gets to the next anchor, he can tie the pull line straight to the anchor (or his harness) so that the main rope cannot slip when the second comes down. Not saying this is safer, since it relies on the first correctly tieing the pull line off before the second starts down, but it requires no backup biner.
ontheedgeandscaredtodeath

Trad climber
San Francisco, Ca
May 10, 2010 - 06:24pm PT
I've thought about the single rope/tag line method and can't say I see the point.

In situations where weight is truly critical it makes no sense to bring one larger diameter rope and 180+ feet of 5-6mm cord that's only good for one thing.

Seems like it would take longer to set up-- I know I would be spending a lot of time making sure it is rigged right and there is a lot to look at.

Looks like a cluster to pull over/through anything. Straight down from chains is one thing, but...

Use of an auto locking belay device to rap increases the possibility of giving the anchor a good jolt.

Rapping on a single line has it's own set of problems/risks.

There are a million rap anchors out there with different set ups, the single rope method seems to rely on links. Other methods can be used no matter what one comes across.

Dunno, to each his own.





Ken M

Mountain climber
Los Angeles, Ca
May 10, 2010 - 08:02pm PT
What I find troubling, is the statement of simple opinions, when there are actually facts (that is, actual testing) of the EDK vs Fig 8.

In the below comprehensive test, they found:

"The flat-overhand is clearly better than the flat-figure-eight. The flat-eight is represented three-to-one in the accidents despite (to the best of my knowledge) many more climbers using the overhand. The flat-eight also starts flipping at a lower load (750 lbs vs 1400 lbs for well-tied, 110 lbs vs 200 lbs for badly tied) than the overhand, and it eats two to three times as much tail in each flip."

http://www.xmission.com/~tmoyer/testing/EDK.html

So the actual testing is very clear about which is better, not just opinion and a series of experiences.

Here are some other actual data sites and comments:

Preferred Knots for Use in Canyons - from Bushwalker's Wilderness Rescue Research Page. Long paper with pull-test data on a number of knots used to join ropes, including measurement of the force to drag the knots across edges. The author concludes that the flat-overhand is his preferred choice and that the flat-figure-eight is dangerous.

Chockstone Tech Tips/JoinRopes - good pictures of knots and discussion. No testing. They express a preference for the figure-eight follow-through, and show the flat-figure-eight knot with a skull-and-crossbones.

Edelrid tests - (in German, with much of it translated into English). Test data on three knots: the flat-overhand, the double-fisherman's tied as a flat-knot (photo at right from their page), and on a new type of flat-knot. He translates it as "Triple Fisherman's", but it's not. The flat-double-fisherman's didn't invert at all in his tests. Cool! People have asked me about it, but I haven't done any tests.

Abseil Knots - from NeedleSports. Pull-test data on the flat-overhand and flat-figure-eight, including data on frozen ropes. The author prefers the flat-overhand with a second overhand as a safety (he calls this the double-overhand). He calls the flat-figure-eight the "instant-death knot."

mucci

Trad climber
The pitch of Bagalaar above you
May 10, 2010 - 08:08pm PT
^^^^

Nothing says safe like a properly tied 8 or fisherman with overhand finish.


Can't say the same for the EDK.

Oh and I don't know the actual #'s but I rarely see the EDK being used, and I highly doubt it is the knott used by "MOST" for rappeling as stated above.



Edit: I thought we were talking about the inline 8. I meant the quoted sentence above from the testing company.

No reason for a "Flat" knott in my opinon.
Ken M

Mountain climber
Los Angeles, Ca
May 10, 2010 - 08:10pm PT
I didn't state that, the tester stated that. His experiences are probably vastly larger than the small number of places that you climb.
climbingcook

Trad climber
sf
May 10, 2010 - 08:12pm PT
I've never seen anyone use a flat figure eight to rap on. When people are talking about using a figure eight to join two ropes to rappel, they're talking about using a flemish bend.
mucci

Trad climber
The pitch of Bagalaar above you
May 10, 2010 - 08:16pm PT
^^^

This is the knott I was referring to, knott a in line.

So the argument for a "Flat" 8 is mute. Nobody uses it in climbing. It has always seemed dangerous to have opposing force applied to a knott.
bluering

Trad climber
Santa Clara, Ca.
May 10, 2010 - 08:19pm PT
His experiences are probably vastly larger than the small number of places that you climb.

What does that have to do with knot strength or tendency to fail? The location makes a diff?
scuffy b

climber
Where only the cracks are dry
May 10, 2010 - 08:24pm PT
I have seen the flat-figure-8 used to join two ropes for a rappel.
First reaction, shock. When I pointed out the flaws with the knot, I was
informed that I had supposedly recommended it at an earlier date.

A mistake, which fortunately was not tested. We switched to the good old
EDK (flat overhand) for our descent.
In fact, when I learned the knot, the first thing I was told is that the
flat 8 is no good. There's no way I would have recommended it, ever.
Chiloe

Trad climber
Lee, NH
May 10, 2010 - 08:27pm PT
There might be confusion with the names but some people definitely have used the "flat 8," and I've seen them (wrongly) claim in writing that it was safer than a flat overhand or EDK. A flat 8 was the cause of a Zion fatality a few years back.

IFO use the EDK or flat overhand most of the time, including ropes of somewhat different diameters (like an 8.8 and a 10, wouldn't try it with a 6 and a 10). The tests I've seen say that's fine.

I don't know what "most" climbers use but the EDK does seem pretty common.
Paul_in_Van

Trad climber
Near Squampton
May 10, 2010 - 08:41pm PT
My system is a 7 mil trail line and a single lead line (9.4 to 10.5+, whatever dia doesn't really matter).

I use an well dressed EDK (or overhand knot for those that are sensitive) with long tails (2' typically) and rap both strands with a reverso.

The slippage on the thin line can be an issue, so I monitor the potential slippage and as an additional precaution have a 80m trail line which matches to a 70m lead line with allowance for stretch and some slippage.

I might play with the double loop EDK as it sounds like it doesn't exhibit knot roll, but my tails are long enough that they can handle any rolls that might happen (and the test data shows that the force required to roll gets higher with each roll to the point that the rope fails at the knot directly rather than rolling off the end of the tails). I seem to recall that this took two or three rolls (is this Tom M's data? I haven't checked the link above to be sure.

End of the line here is that overhand 8 (force required to roll gets lower with each roll) is a horrible idea and if you are going to rap a single strand you better have a bulletproof safety system in place.

P

bluering

Trad climber
Santa Clara, Ca.
May 10, 2010 - 08:47pm PT
What's the diff between a 'flat 8' and a Flemish 8 follow through???
tradmanclimbs

Ice climber
Pomfert VT
May 10, 2010 - 10:01pm PT
I don't get all this talk about EDKs rolling. use it lots but never seen it roll. I do dress it properly.
rockermike

Trad climber
Berkeley
May 10, 2010 - 10:17pm PT
here's one (older) discussion on rapping knots

http://www.xmission.com/~tmoyer/testing/EDK.html
climbingcook

Trad climber
sf
May 10, 2010 - 10:18pm PT
What's the diff between a 'flat 8' and a Flemish 8 follow through???

flemish bend, flat 8. The flemish bend is a sane way to join two ropes to rappel, the flat 8 isn't.
Chiloe

Trad climber
Lee, NH
May 10, 2010 - 10:30pm PT
I don't get all this talk about EDKs rolling.

Most people use "rolling" to refer to the way the EDK starts to fail in static pull tests -- it has to invert first (at something over 1,000 pounds). Unless the tails were tied short, it then has to invert again, and again to reach the ends. Not sure whether static tests have followed that all the way through an 18" set of tails (what I usually tie).

I used "roll" to mean something different in another thread, the simple fact that an EDK pulled over an edge tends to "roll" so the knot sticks up and the smoother side slips over the edge. That's a good feature in most rap setups but maybe a dangerous one if it gives the knot a chance to slide through a biner or large-opening rap ring.
bmacd

climber
Relic Hominid
May 10, 2010 - 10:50pm PT
bluering

Trad climber
Santa Clara, Ca.
May 10, 2010 - 11:17pm PT
Thanks climbingcook, I agree....
High Fructose Corn Spirit

Gym climber
Full Silos of Iowa
May 10, 2010 - 11:22pm PT
Nice to see the two different forms of figure 8 being talked about. And distinguished by way of language.

Back in the day, when I was trying to get straight on the phenomenon of inversion of knots (esp in overhand and figure 8), I called the two figure 8 types homo and hetero, short for homogonal (same side) form and heterogonal (different side) form I think, my own terms, to help me distinguish them in thought and practice.
Delhi Dog

Trad climber
Good Question...
Topic Author's Reply - May 11, 2010 - 12:35am PT
Here ya go fatty
KNOTS


Flat 8

Flemish Bend/ Figure Eight Bend


Flemish Bend/Figure 8 with stopper knotts


Kleimhist/AutoBlock (Friction Knott)
**^^The picture stands corrected by this statment;

"The "Autoblock" is essentially the same knot as the Klemheist, except that in the last step you simply clip both tails together with a carabiner, rather than feeding one through the other."

Prusik
How to tie both
http://www.chockstone.org/techtips/prusik.htm

Single Rope set up used "correctly" from Petzl

And once again this link
http://web3.bdel.com/scene/beta/qc_kp_archive.php#123008

Cheers,
DD
rgold

Trad climber
Poughkeepsie, NY
May 11, 2010 - 12:42am PT
I'd like to reiterate something mentioned by Ken M a while back, which is that it is extremely unlikely that a prussik above will catch a rappeller who goes off the end of the rope, and in fact there is a very good chance that a prussik above will not work in any emergency situation in which the rappeller is conscious, because the rappeller has to release the prussik in order for it to grab and this is beyond counter-intuitive.

The tests referred to were done by cavers, not guides, but made it clear that even when very experienced rappellers knew exactly what was going to happen and prepared themselves to act appropriately, they were still frequently unable to release their grip on the overhead prussik in time for it to grab. The test set-up had the rappellers using a short rope for their device but the prussik was on a long continuous rope. When they rappelled off the end of the short rope, their grip on the prussik kept it from locking at all on the long rope and they had to be stopped before the ground with an independent upper belay.

The only thing that will keep a rappeller from going off the ends of a rope are knots in the ends, which in some cases can cause a serious hang-up problem, especially if it is windy and the ropes are blowing sideways. Each situation has to be evaluated on its own merits in deciding whether or not to knot the ends, but under no circumstances should anyone trust this task to a prussik in either position; at least that's my opinion.

Discussions of rappel backups almost never seem to consider the position a party will be in with an unconscious rappeller hanging, say half way down an overhanging rappel, frozen in place by an activated prussik backup. I think rappel backups should only be used, if at all, by the first person down. Everyone else should get a fireman's belay from below, which eliminates for the rest of the party the very difficult and dangerous rescue scenario of trying to get an unconscious rappeller down before he or she succumbs to suspension trauma.

As for EDK's I like the name and the knot. Anything that concentrates the mind on the potential for death when rappelling is a good thing, I think. I absolutely hate tag lines, but as a dyed-in-the wool double rope user for many years now, I no longer have any occasion to use them. For those that do, perhaps it is mentioning that there is a "right" way to tie the EDK with ropes of different diameters; hopefully the picture below is self-explanatory. (Note: ends are short for pictorial convenience, the real knot should have forearm-length ends.)


Those wanting a a bit of extra security (on ropes of the same or different diameters might consider adding another overhand for extra roll protection, as in


Doug Robinson

Trad climber
Santa Cruz
May 11, 2010 - 12:47am PT
ec --

Strength isn't the issue in a prusik. I like stronger cord for its other uses. I can use my prusik to tie off small knobs, where it's strong enough to be pro. Or use it as a runner. Not specialized gear, it comes in handy for lots of stuff.

Low melting point isn't an issue either. I don't do ripping fast raps cuz it's too hard on the rest of the system, like overheating your rope with the rap device. Of all your gear, be gentle with your rope!

And haste is more likely to shock load the anchor -- who needs that?
Delhi Dog

Trad climber
Good Question...
Topic Author's Reply - May 11, 2010 - 12:49am PT
Thanks for the addition of the EDK.

Mighty Hiker

climber
Vancouver, B.C.
May 11, 2010 - 01:04am PT
Regarding DD's and rgold's photos:
 I've never seen or heard of anyone using a flat figure 8 for rappelling, and can't imagine doing so. Scary!
 I don't like the look of the EDK, but can accept it might at times be a practical solution.
 The Flemish bend looks much the best, although DD's second example (long tails) looks healthier to me. It's the one I most commonly use, both because the figure 8 is such a standard and foolproof knot, and because it works to join ropes from 6 - 11 mm.
 Glad we no longer use the double or triple fisherperson's, as they can be a pain to untie. But they work, although not so well with ropes of significantly different diameter.

The EDK/reepschnur/blocking knot & carabiner system seems an unnecessarily complicated solution to a simple problem. A last resort, not a first.
Ken M

Mountain climber
Los Angeles, Ca
May 11, 2010 - 02:19am PT
"His experiences are probably vastly larger than the small number of places that you climb."

What does that have to do with knot strength or tendency to fail? The location makes a diff?
----------------


Bluering, if you read his original post, to which I was responding, he doubted the veracity of the tester's statement, based upon his experience.

If one's experience location is limited, it will neccessarily give a bias, and a false "sense" of what people are widely doing.

Clear?
Delhi Dog

Trad climber
Good Question...
Topic Author's Reply - May 11, 2010 - 08:07am PT
"I've never seen or heard of anyone using a flat figure 8 for rappelling, and can't imagine doing so. Scary!"
Yep, could not image using that knot either.

tradmanclimbs

Ice climber
Pomfert VT
May 11, 2010 - 10:17am PT
Back to the EDK rolling thing. Dress it tight. It may roll in static pull tests but it will NOT roll in climbing aplication if you dress it tight and neat. If it ever does roll then YOU tied a sloppy knott.

Back up below vs above. First I never would have bit on this one except DR called the autoblock below the device Idiotic or some such thing.

The prusic above the device locks up when you don't want it to and slips when you want it to lock.. It requires much more force to lock up unless it is jamming by accident in which case it takes very little force. Murphy has his tricks. It takes lots of force and tricks to free up again.

The autoblock below the device takes very little force to work. It does not support the climbers weight but merely acts as the brake hand to activate the rappell device. Locks up easy, easy to unlock. Also can be applied to the rope before you stuff the rope into your rap device takeing the weight off the rope and makeing it easy to get into your device.

Use whatever you like but don't call this very usefull method idiotic simply because you are too stubborn to learn it correctly ;)
donini

Trad climber
Ouray, Colorado
May 11, 2010 - 10:24am PT
I have made thousands of rappels in my 45 years of climbing, many of them under extreme conditions- Latok 1, Patagonia and Alaska come to mind. The only given is to pay COMPLETE ATTENTION to what you are doing.
tradmanclimbs

Ice climber
Pomfert VT
May 11, 2010 - 10:40am PT
Yes. Especially be METHODICAL when setting it up.
Manjusri

climber
May 11, 2010 - 10:46am PT
Nice pics Delhi. The Kleimheist pic is not an autoblock, though they are similar. In the autoblock the cord/runner does not pass through itself before clipping.
wbw

climber
'cross the great divide
May 11, 2010 - 11:28am PT
There are obviously many ways to safely rappel, and favoring one system over another clearly comes down to personal preference. However, I cannot figure out where the "flat figure 8" enters this discussion.

I have never climbed with anyone that has tied that knot to link two rappel ropes together.

The figure 8 follow thru, on the other hand, is strong, simple, easy to check, does not require back-up knots (although back-up knots are almost never a bad idea), and is easy enough to untie with gloves on. Also, it does not roll when weighted. It is reasonably low in profile such that it rarely (if ever) snags on the pull.

Why the flat figure 8??
climbingcook

Trad climber
sf
May 11, 2010 - 11:39am PT
Why the flat figure 8??
My best guess is that it comes from people reading about joining two ropes with a figure eight and assuming they should be tied like an eight on a bight.
tradmanclimbs

Ice climber
Pomfert VT
May 11, 2010 - 11:45am PT
Na, pretty shuer it come from folks learning the EDK and thinking its too flimsy so they think they are super smart and figuer they can do the same thing with a fig 8 and have a stronger knott.. OOppps Splat...
climbingcook

Trad climber
sf
May 11, 2010 - 11:49am PT

While we're discussing incorrect figure eight knots for rappelling, why not use two figure eights on bights girth-hitched together? It's needlessly complex, it's likely to snag, it takes a relatively long time to tie, and it has no obvious benefit...


Someone should suggest it on rc.com...
Mighty Hiker

climber
Vancouver, B.C.
May 11, 2010 - 11:50am PT
A Flemish bend by definition never 'rolls', and you need never fear that it might. QED.

In the spirit of RC.noob, climbingcook's knot is totally wrong. The loop of one bight should simply loop/catch the other - there's no need to make a reef knot of them.
Delhi Dog

Trad climber
Good Question...
Topic Author's Reply - May 11, 2010 - 11:55am PT
"The Kleimheist pic is not an autoblock, though they are similar. In the autoblock the cord/runner does not pass through itself before clipping. "
-Thanks!
The picture stands corrected by this statment;

"The "Autoblock" is essentially the same knot as the Klemheist, except that in the last step you simply clip both tails together with a carabiner, rather than feeding one through the other."

from http://www.chockstone.org/techtips/prusik.htm


"Why the flat figure 8?"

Only put it there because it was referenced earlier...agreed by all that it is NOT the KNOTT to tie.
Cheers,
DD

edit...okay almost all...those pesky Euros :-)
rgold

Trad climber
Poughkeepsie, NY
May 11, 2010 - 12:00pm PT
Climbingcook, you may think that is a joke, but many of us used something very similar for years: a square knot backed by double-fisherman's. A bit on the bulky side, but not hard or slow to tie, and unmatched in ease of untying.
ExtraBlue

Ice climber
the ford VT
May 11, 2010 - 12:03pm PT
DR

When you make prussiks from Spectra over Nylon doesn't this increase the chances of melting-heat damaging the prussik since Spectra has a lower melting point??
-Random Question
bluering

Trad climber
Santa Clara, Ca.
May 11, 2010 - 12:26pm PT
In the spirit of RC.noob, climbingcook's knot is totally wrong. The loop of one bight should simply loop/catch the other - there's no need to make a reef knot of them.

I'm not proud to say I did that recently...seemed quick and solid.

I'm sticking with the Fig-8 follow through.
Jay Wood

Trad climber
Fairfax, CA
May 11, 2010 - 12:30pm PT
I'm with Tradmanclimbs.

 prussic above= idiotic. Prone to locking up, out of reach, hair pull, etc, etc.

 low melting point cord= not smart. Supposed to be safety for emergency situations, right? Like if you lost control and gained too much speed...

 multiple raps call for threading alternate ropes through anchors, so be able to pull either rope.

 IMHO, one of the most dangerous scenarios is getting the rope stuck when pulling it. Therefore, EDK, no super skinny lines, sometimes not even knots in the rope ends. Definitely no biner at the knot.

 I use lead line, 7.8mm trail/rap line (dynamic- emergency lead line doubled), and deal with slight knot creep. Also autoblock from 6 mm nylon cord

 benefit of autoblock below device includes that the cord takes the friction/heat/oxides, not the hand

 If there's any rope stick potential, DON'T let the newbie pull the rope!
tradmanclimbs

Ice climber
Pomfert VT
May 11, 2010 - 12:46pm PT
Never forget to say a prayer to the rope gods just as you pull the rope.....
cleo

Social climber
Berkeley, CA
May 11, 2010 - 02:48pm PT
How to thread a single rope through both ATC holes to increase friction and control: especially useful with super skinny rappel lines when it is hard to maintain control.

I've done this ONCE on a 7mm rap line, after balking on rapping the "normal" way. My friend suggested it, I tried it, and it works.

But I've never seen it elsewhere. So I welcome all comments!


from the top:

from the bottom:
Chiloe

Trad climber
Lee, NH
May 11, 2010 - 02:53pm PT
I'd be a little nervous because that rig bets your show on the cross-piece of the ATC,
which is not a beefy part.

The double- or triple-biner system seems more bomber.
climbingcook

Trad climber
sf
May 11, 2010 - 02:55pm PT
How to thread a single rope through both ATC holes to increase friction and control: especially useful with super skinny rappel lines when it is hard to maintain control.

I've done this ONCE on a 7mm rap line, after balking on rapping the "normal" way. My friend suggested it, I tried it, and it works.

But I've never seen it elsewhere. So I welcome all comments!

I wouldn't be all that comfortable with that setup. The way you've got the rope threaded across the center bar of the ATC means the bar is the only thing keeping you from cratering.
ontheedgeandscaredtodeath

Trad climber
San Francisco, Ca
May 11, 2010 - 02:56pm PT
I wouldn't do that. Nor would I rap on a 7mm. I think a lot of these weight saving tricks inject unneeded risk and complication.
Mighty Hiker

climber
Vancouver, B.C.
May 11, 2010 - 03:02pm PT
Another way to increase control when rappelling with a thin rope or ropes, when using a 'standard' belay device (9 - 11 mm), is to reverse it so that the wide/flared end of the device faces away from the carabiner, and the narrow end is in. Also, to use a second and even third carabiner to clip the rope and device to the harness. It may be a bit jerky, but works.
tradmanclimbs

Ice climber
Pomfert VT
May 11, 2010 - 03:09pm PT
The best way to doubble your brakeing power is to simply add a 2nd locker.
cleo

Social climber
Berkeley, CA
May 11, 2010 - 03:10pm PT
Yes, interesting - the center bar is indeed the only thing keeping the rappel going, when normally it is the thicker ATC walls.

If the center bar fails = disaster.
If the outside (hand side) wall fails = probably disaster.

But one is designed for the load, and the other, presumably, is not.





High Fructose Corn Spirit

Gym climber
Full Silos of Iowa
May 11, 2010 - 03:14pm PT
Cleo- that's the dumbest rigging relating to rappel I've ever seen. Chiloe is exactly right. That would be an emergency-only system. And what would require that? when better options exist. An accident waiting to happen. Wow!
Edge

Trad climber
New Durham, NH
May 11, 2010 - 03:18pm PT

I don't use this method, as I generally climb on doubles or with a similar sized haul line.

It seems to me that if the knot got shock loaded enough to pull through the rap ring, say via an aggressive rappel, bounce, whatever, only then the biner would come into play and prevent tragedy.

But couldn't it also then become damned near impossible to pull it back through to retrieve the line? Especially if it is a full length rap and you are playing against 70m of rope stretch?

Elucidate me.
cleo

Social climber
Berkeley, CA
May 11, 2010 - 03:36pm PT
See, I'm glad I asked and glad I only used it once when I was first starting. Now I can go chat with my (far more experienced) friend who showed this to me in the first place.

I rarely rap on a single line, fwiw. Usually 2 lead lines with a prussik/autoblock or a fireman's belay. Or I find a walk off.
rockermike

Trad climber
Berkeley
May 11, 2010 - 03:40pm PT
I thought Cleos setup was pretty cool. I suppose it depends on which ATC you are using but I can't imagine the crossbar blowing from rapping. Now rapping on a 7 mill. that WOULD get my hair standing on end - though I have rapped with a pig on a single 8 mill. Scary enough.
Chiloe

Trad climber
Lee, NH
May 11, 2010 - 04:02pm PT
I can't imagine the crossbar blowing from rapping.

Your imagination is better-behaved than mine is!

That ATC cross-piece might be strong, but I'm pretty sure they didn't design or test it for direct force like that.

Even the much thicker tube walls of an ATC wouldn't normally have to take the full weight of a rappel or a fall. That's the biner's job.
High Fructose Corn Spirit

Gym climber
Full Silos of Iowa
May 11, 2010 - 04:03pm PT
Cleo- I take my adjective back. Who's to say what "dumbest" is in this sport. Would I bet I could rap your rig 999/1000 times safely? Yes. So would that be dumb? Everything's relative. Who's to say. Not me. I've done dumber things.


EDIT

I can't imagine the crossbar blowing from rapping.

What would concern me is an unforeseen weakness, crack (from metal fatigue, etc) on the crosspiece out of view somewhere and then the crosspiece under load cracking off before my very eyes.

(I already worry about my old ATC in standard mode-- cracking and crumpling in places on rappel-- and what I'd have to do quickly in response, that's enough.)

Much "dumber" is not replacing my ATC every few years.
rockermike

Trad climber
Berkeley
May 11, 2010 - 04:09pm PT
OK, I stand corrected; it appears the original BD ATC has a pretty thin cross-member (as in Cleo's photo). Maybe shaky. For myself, I have a BD Guide,and the middle cross-member is a solid wall. Plus the whole thing is designed to hang off the eyelet when used in autoblock mode. So I still can't imagine... ha
cliffhanger

Trad climber
California
May 11, 2010 - 04:12pm PT
Here's a possible scenario for an EDK: two brand new slick polished shiny new ropes, a wet day, and you just had some salami adding some grease to the equation. You tie the EDK, start your rap, it rolls thru all 18" of the tails. The dirt nap.

You could make the EDK safe by tying a good knot in the tails: Flemish bend, overhand follow-thru (not the EDK), or even a sheet bend.
Mighty Hiker

climber
Vancouver, B.C.
May 11, 2010 - 04:16pm PT
The Petzl diagram of the EDK setup might be improved if the two ropes were differently coloured, and it clearly identified which rope was which in terms of diameter.
cleo

Social climber
Berkeley, CA
May 11, 2010 - 04:20pm PT
What would concern me is an unforeseen weakness, crack (from metal fatigue, etc) on the crosspiece out of view somewhere and then the crosspiece under load cracking off before my very eyes.

I worry about that too in a standard rappel setup. Actually, I worry a lot about that - If those walls blew, you're hosed even with the biner taking some (most?) of the load (does it take most of the load? I'm not so sure...)

I currently use an ATC XP - MUCH thicker walls than the original ATC. Much thicker center cross-piece.


I'm on my 3rd ATC because I worry so much.
cleo

Social climber
Berkeley, CA
May 11, 2010 - 04:21pm PT
ATC XP

Gene

Social climber
May 11, 2010 - 04:24pm PT
The Petzl diagram of the EDK setup might be improved if the two ropes were differently coloured, and it clearly identified which rope was which in terms of diameter.


Agreed. The Petzl diagram shows only a single rope - I don't see any knot connecting two different cords. Why would anyone EVER use this set up with a single rope rappel?

By way of contrast...
g

Pictures lifted from other posts.
Mighty Hiker

climber
Vancouver, B.C.
May 11, 2010 - 04:27pm PT
Appreciating that gene's photo may be for illustration rather than real-world, it's weakness being use of a single link and a single sling. No redundancy. It may be a brand new sling, properly tied, and the link may be a brand-name one, properly closed. And of course sometimes you just don't have stuff to spare. But redundancy is a virtue.

And looking at the knot joining the ropes in the photo - why not use a Flemish bend there, with tails? Seems simpler and more reliable than what is shown.
Gene

Social climber
May 11, 2010 - 04:42pm PT
Mighty Hiker,

Could not agree with you more. I just can't see any benefit to the pull cord method beyond the couple of pounds difference between a 5 or 6 mm pull line and a 8 or 9 mm rope. Not enough to satisfy the risk/reward equation.

As I understand it, the set up involved in the fatality lacked the figure 8 on the pull side and the biner attached to the rap side line. So sad.

Quoting shipoopoi

whatever system you are using, i encourage a ritualistic approach to setting up rappels, where one is in the zone, not talking to anybody, and making the system from start to finish without interuption.

Jay Wood

Trad climber
Fairfax, CA
May 11, 2010 - 04:52pm PT
Rapping a single skinny cord, a munter hitch would be probably be safer and better control.

Maybe add an extra turn around the spine of the biner.

That atc setup gives me the willies.
cliffhanger

Trad climber
California
May 11, 2010 - 05:01pm PT
Werner made an excellent post, one of the best so far and bears repeating:

Werner Braun: I rapped with 7mm for 20 years with the 7mm thru the anchor and always pulled the lead line. There's no slippage if you use a figure 8 correctly with an added friction biner. Those new fangled rappel gadgets might be a problem though and that's why I still use a figure 8 today.

Always be alert to potential problems and have for-thought before you do anything is the motto.

Gene

Social climber
May 11, 2010 - 05:04pm PT
What about this for a single skinny cord set up?

climbingcook

Trad climber
sf
May 11, 2010 - 05:06pm PT
The Petzl diagram shows only a single rope - I don't see any knot connecting two different cords. Why would anyone EVER use this set up with a single rope rappel?

The illustration has no EDK or flemish bend because it's showing only one rope. They're illustrating how to rappel safely using a grigri.
Chiloe

Trad climber
Lee, NH
May 11, 2010 - 05:08pm PT
Gene, there's less redundancy than it appears in your 3-biner rig!

Like rgold, I'm happy to use double ropes (8.8s) when I know we'll need 2 to get down.

JimE, being an ice climber, and brought twin 7.7s on our rock climb last fall.
That works too, they're dynamic so I guess you could lead on one if you had to,
and no tricks are needed to rappel.

slobmonster

Trad climber
OAK (nee NH)
May 11, 2010 - 05:11pm PT
The illustration from Petzl is only that: an illustration.


It does indeed show one rope with a bight tied into its middle; it should not take you much imagination to conceive the same setup with two ropes tied together.

It's not a common technique for rock climbers to use as mode of descent, but rather more prevalent among cavers and canyoneering enthusiasts and the like. Translation: these people use the rope as a descent tool PRIMARILY, and not as a descent tool SECONDARILY (as we climbers do).

Utilized correctly, it allows for full-length rappels with the slight added weight of a skinny pull cord.

Now. Cleo, you *know* I'd roll my eyes so far back as to SEE BEHIND ME if you ever showed me such ATC shenanigan malarkey.

Some variations on a (perhaps) better ways (more controllable, more comfortable with a pack); as noted above you can add/duplicate the belay carabiner to add some more friction:

Redirect the brake strand, or

Extend device and redirect brake strand, or

Extend device and integrate an autoblock.

Euro-style belay/rappel sling, for extending effective belay loop.

Or if you have a plaquette device (ATC Guide, Reverso, and the like), this makes for a nice, smooth descent, and won't sharpen that pesky edge:



phile

Trad climber
SF, CA
May 11, 2010 - 05:22pm PT
Seems like most people are talking about a prusik above the device vs. an autoblock below the device. Is there a reason for the two different friction knots in the different places?
Mighty Hiker

climber
Vancouver, B.C.
May 11, 2010 - 05:24pm PT
Thank you - point taken. And Petzl is as much or more a supplier of caving as it is of climbing equipment. But climbers most often rappel with two ropes, given that rappels are typically more than 40 m. So a diagram showing that application is what's needed.
HighTraverse

Trad climber
Bay Area
May 11, 2010 - 06:13pm PT
Hello MightyHiker
I take exception to this
In the spirit of RC.noob, climbingcook's knot is totally wrong. The loop of one bight should simply loop/catch the other - there's no need to make a reef knot of them.
With this configuration there are two problems.
The strength of BOTH bights is reduced by the extremely small bend radius that can result under load. Both bights will deform into a 'pinch'. When the bight is over a biner the biner is limiting the minimum radius of the bight.
#2: with multiple rappels there may be significant chafing between the two bights. Something that all the "static" knots avoid.

Given the apparently good choices between double fisherman's and EKD, I'll have a look at but will be very sceptical of any other knot.

I posed a question earlier that hasn't been answered.
What's the best knot to put in the rope tails?
Best = won't pull through brake and won't untie itself in the wind.
Mighty Hiker

climber
Vancouver, B.C.
May 11, 2010 - 06:17pm PT
Just joking - in the unlikely event that I used the EDK system, I'd use a Flemish bend to join the ropes, with ample tails and backup knots.

The EDK system as depicted seems an unnecessarily specialized and complex solution to a general situation.
HighTraverse

Trad climber
Bay Area
May 11, 2010 - 06:28pm PT
cleo
Referencing your pic. Thanks for posting it as I was wondering how it was done.

I would be less worried about the internal rib breaking (OK, so I have too much faith in the aluminum).
I'd be more worried about excessive heat build up and stress on the rope due to the extremely tight radius around the center rib.
All the rope testing is done with a "meaningful" radius bight such as around a 'biner.
The stress in the fibers goes up as an inverse power of the radius. Heat and stress combined are what makes ropes fail.

I'm not dismissive of the need to rapp on a 7mm although I've never done it.
I'm over 200 lbs with clothing and a rack. Suppose the lead rope is lost/severely damaged, etc.
I've never gone out without at least 8mm ropes. The ATC Guide is specifically designed for this diameter.

If I had to rapp on 7mm I might add friction to the ATC with a Munter hitch around another locker on my harness. Simple and using all components in the way they were intended.

I don't use a GriGri or other device that requires moving parts for a variety of reasons. If I ever do, I'll carry an ATC for rappel. It weighs nearly nothing.

From this discussion I've become convinced that an autoblock knot is superior to a Prusik for descending. And possibly that I should use it every time.

Fred
August West

Trad climber
Where the wind blows strange
May 11, 2010 - 06:42pm PT
I had a very unpleasant and somewhat dangerous rap experience when I had tied knots in the end of the ropes and one of the ends blew sideways and caught behind a flake. Caused me to stop putting knots in the end. I usually rap with the trango Jaws and the weight of the rope itself is usually enough to lock the device off (to work on tangles I wrap rope on leg).

An alternative rap method that I have played around with (although I have posted this before--and alas I couldn't find it--this looks like a good thread to bring the idea up again):

For a multi-rap descent with two raps (not a super skinny tag line) the ropes are ready to be pulled from the previous rap:

Pull the rope (rope A), feeding it through the anchor, and keep this rope bunched up at the belay. Rope B falls below you. Clip rope B straight to the anchor (figure 8 on bight/clove hitch with locking biner). Clip the end of rope A to the first climber (locking/clove hitch is fine since this is a backup). First climber raps rope B while second climber belays them (using rope A). First climber can rap using a cinch, only has one rope to deal with tangles, and doesn't need an autoblock backup/knots in the end of the rope since they are being belayed. When they get to the next anchor and have clipped in, Second climber unties Rope B from the anchor and can now do a normal two rope rap while being fireman belayed by first climber.

First climber is not being lowered, he can control his speed/stop whenever. Depending on the belay device and comfort level, a pretty skinny second rope could be used. I'm comfortable using a cinch on an 8.1, and with a belay from above there are plenty of setups where a 7mm static would be fine.

My partner and I have done this a few times. I think with practice it wouldn't slow you down much (especially if attachments are made with a clove hitch). The first down only having one rope to untangle makes up for some loss time and I carry a cinch on multi-pitch anyway (which makes for a nice rap of a single rope). Although I have not managed to make this my standard rap method--but reading the accidents reports might help me get there.
the Fet

climber
Tu-Tok-A-Nu-La
May 11, 2010 - 07:02pm PT
I'd rather fall then be trapped on the wall and suffer a slow death, so I:

Use an EDK unless ropes are very different diameter, then I use a flemish bend / figure 8 follow through. The EDK is the least likely to get caught, I leave pleny of tail, no other knots. I like the name too. The flemish bend is much easier to untie than double fishermans.

I don't put knots in the ends when there's any chance they could blow to the side and get caught. I always watch the rope ends below me.

I use the autoblock below and often extend the belay device 12" above the belay loop. I like to be able to stop and rig the next anchor or take photos, or put on my headlamp/jacket with no worries.

As usual rgold's post was great, I will start using a fireman's belay for everyone but the first one down in case a rescue is needed.
Clint Cummins

Trad climber
SF Bay area, CA
May 11, 2010 - 07:13pm PT
I don't like this example so much. Better to run the rope around behind your butt - more friction than a biner. I could see running the rope under your butt, then through a biner on the far side and down.

Plus, you should try not to create a situation where you have to lift and hold the rope up to add friction. It should be a downward motion of your arm. (Although technically when moving the rope under your butt, you are moving the rope weight to the side, and eventually lifting it on the far side of your butt).
Same principle is why it's risky to belay your follower from an ATC right on the anchors above you. You need to have an easy way to angle the braking side of the rope to create maximum friction in the ATC, and you need degrees of freedom to create any angle. Running the rope through the second biner in the photo above reduces your degrees of freedom greatly.


My personal rappel preferences for Yosemite are:
 Flemish bend / rewoven Figure Eight to join 8.1mm (dynamic) and 9.X/10.0 mm ropes
 EDK profile not needed on Yosemite granite or Indian Creek; would be good in Dolomites and maybe Red Rocks
 EDK prone to wear in a single spot and core shot the ropes. This happened while toproping one climb at Indian Creek. Figure Eight wears at random points on the surface of the knot.
 short ends (about 3") with Figure Eight - less rope to cut off the end if it does get a core shot (I will compromise to slightly longer if my partner objects)
 no "backup" knots
 neat/tight knot
 thread the 8.1mm through slings or rings/chains - easier to pull the fat one, easier to pull the 8.1mm out free from the wall, if the 8.1mm gets stuck you still have the lead line
 put knot on the side where you expect to be pulling from, so ropes are not crossed
 no knots in the ends, unless it's overhanging/dark and we can't see the next anchor point
 remove tape from ends of rope - it increases risk of getting end stuck in a crack
 ATC on locking biner on my belay loop for most rappels
 Munter hitch on locking biner when rapping single strand 8.1mm
 no "simulrap" - needless risk
 a 5mm cord is the waistbelt for my chalk bag, for emergency prusking
 a tiny knife on this cord, good for cleaning old slings from bolt anchors and cutting rope or hair/clothing if necessary
 if I'm rebolting or on a wall, I have my jumars out and clipped to my belay loop, so I can stop anytime, pass knots, etc.


I've witnessed the following rappel incidents:
 my joining knot stuck in a crack (Bugaboo Spire, 1974) Easy 4th class solo to free it.
 rapped solo to a hanging station. Before pulling the ropes, I was fiddling with the anchor. I wasn't paying attention and let go of the ropes. They drifted over about 9' to my right, out of reach. I put a biner or Fifi hook on the end of my aiders and managed to snag them...
 core shot to shared ropes with EDK on sandstone toprope mentioned above
 my lead line hung up on rappel down NE Face of S Howser, because we didn't pull the rope out clear of the face - wall above not climbable without pitons; we had to cut off 30m
 party above us simulrapping down to Sons of Yesterday belay tree - one of their knotted rope ends hung up in the crack well below the belay tree. This made it impossible to pull their rope, unless they got the knot out of the crack, but they did not have enough rope to belay down there, unless they climbed partway up the pitch above to free rope. Fortunately my partner was climbing up to it and freed it for them.
 partner's taped rope end stuck in a crack (Middle Cathedral, rappel above Turret - forced bivvy and climbed up to free it in the morning)
 very end of my 9mm rope hung up on pointed side of lap link on Harry Daley rappel, because I was lazy and did not deal with slipped sheath which exposed loop in core strands to melted rope end. Reclimbed pitch to free it. Remelted rope end when I got home.
 once while solo aiding, I set up an intermediate anchor to rap down and backclean some gear. After playing with some gear, I went to weight the ATC and it popped off the rope - I had put the loops through the ATC but had not clipped them into the locking biner. Fortunately I caught myself on my "guide hand" and batmanned back to the anchor. It was a case of getting too casual - not checking myself at each step. It also shows the risk of doing something partway and stopping, like tying half your knot - it looks right later but is deadly.
 I was cleaning a climb on a 2 rope rappel when it was finally time to leave. I headed down the ropes, noting a clump in the 7mm partway down. I figured it was the usual tangle. When I got down close to it, I realized I had hit the rope with a loose flake earlier and the bits were cut and melted together. I did not have my jumars out. The first task was to batman up enough to get enough rope below me so that I could tie off the rope on my thigh, and get a knot on it above the bad part. It was steep, and I had weight in a pack, so this was strenuous. Next I had to put makeshift prusiks with slings on both ropes (around both strands might have been better). The ropes went through big lap links, so they slipped back and forth very easily. Much seesaw prusiking and eventually strenuous batmanning ensued, mostly to save time. Then I had to rerig for a couple of single line raps on the lead line.
 my rappel rope hung up on the side of a dirt hummock while cleaning "Gardening at Night" above the Church Bowl. Too much friction on dirt to pull it. Did not have adequate gear/strength to prusik up rope. (Did prusik up 100' with 1" webbing, but it was very slow and I was cramping). Result: I was rescued by Bill Russell and my partner. Made it into Accidents in North American Mountaineering. Could have been prevented if I tested the rope pull while only 30' down the rope, or by having prusiks.
slobmonster

Trad climber
OAK (nee NH)
May 11, 2010 - 07:24pm PT
Clint, I actually agree with you; only showing variations on a theme.

If anyone cares (they don't) I most often abseil with a plaquette device rigged as my photo above, with the brake strand(s) passed under my right thigh. I hold them in my hand on the lateral side.

Seamstress

Trad climber
Yacolt, WA
May 11, 2010 - 07:58pm PT
We have had "rope rescue" missions from the rap rope getting stuck with or without knots tied in the ends. If the wind is blowing or the route looks like a rope eating zone, then take the rope with you and pay it out as you go. It can go into stuff sack, be carried in coils, ....good technique for a final rap above water. Yes, it is slower than tossing the line - unless the line gets stuck. We only need to do this a few times a year.

My husband uses a sling to extend his rap device. That adds friction. I do that occasionally. On low angle slabs, I don't - it is too much friction. The bungeeing effect is a lot of work and can be dangerous if there are any sharp edges. When we use that technique, we usually use two short runners rather than one long one. Is that redundanitis? Yes.

As stated before, have a ritualistic standard. Then assess the situation and adjust if necessary. Adjust consciously.
Manjusri

climber
May 11, 2010 - 09:06pm PT
Phile: "Seems like most people are talking about a prusik above the device vs. an autoblock below the device. Is there a reason for the two different friction knots in the different places?

If you play with the autoblock you'll quickly see why you wouldn't use it above the device. It doesn't create as much friction on the rope as the prussik or kleimheist. It isn't suitable for hanging directly on or ascending.

This also makes it easier to use below the device where it functions like an extra brake hand, using the friction of the belay device to stop the rappel. It glides along the rope easier than a prussik though I have seen someone using a prussik below the device. I typically use a runner for my autoblock (when I use one) for the same reason.
Jay Wood

Trad climber
Fairfax, CA
May 11, 2010 - 09:46pm PT
Toproping aside, one of the merits of the EDK is that the knot rides away from the rock- less prone to wearing through the sheath. This is also the main point, in case you missed it- the knot is less likely to hang up because it rides away from the wall.

Re using fireman's belay (good practice) only because an unconscious climber would be stuck up there:

It's hard to imagine when you would lower that person herky-jerky, or more probably- bump and bang over rocks, especially not knowing the injuries. So more likely you would ascend the ropes to assist, making the rappel back-up a benefit to the situation.
Clint Cummins

Trad climber
SF Bay area, CA
May 11, 2010 - 10:38pm PT
> one of the merits of the EDK is that the knot rides away from the rock- less prone to wearing through the sheath.

Actually, I believe it's the opposite. The EDK concentrates wear on the 2 strands where they emerge from the knot and bend at 90 degrees.
The rewoven Figure Eight puts wear at random points on the surface of the knot.

I agree, though, that toproping/lowering will probably wear the rope a lot more than pulling a rappel.
bmacd

climber
Relic Hominid
May 11, 2010 - 11:40pm PT
The recurring flaw here, is the folks using belay devices for rappels. Someone died using a Cinch.

I am with Werner, always used figure 8 device or a set of ovals, shipoopi's advice is also very good
Jay Wood

Trad climber
Fairfax, CA
May 12, 2010 - 12:59am PT
Huh.

I'll check that out.


Of course, the figure eight is more likely to cause the severest wear- chopping the stuck rope!
Dr.Sprock

Boulder climber
Sprocketville
May 12, 2010 - 01:05am PT
anybody use the reverso 3 in autobrake mode?



note that the fig. 8 knot is safe when used to tie a rope to the harness,

as it is being pulled from 3 of 4 leads.


we need a scuba diving white 3 by 5 message card with grease pencil boxes for checking off every rap,

both people, military style for absolute safety when totally fried.


Ed Hartouni

Trad climber
Livermore, CA
May 12, 2010 - 01:22am PT
from the Petzl catalog...

http://www.petzl.com/catalogue/Petzl-Sport-catalog-2010-GB.pdf
(it takes a while to download but it's worth while)

WBraun

climber
May 12, 2010 - 01:31am PT
Let's see ...

The original mistake was forgotten biner.

Then everyone runs amok in this thread going every which way how to rappel.

Good grief ....
slobmonster

Trad climber
OAK (nee NH)
May 12, 2010 - 01:42am PT
> one of the merits of the EDK is that the knot rides away from the rock- less prone to wearing through the sheath.

Actually, I believe it's the opposite. The EDK concentrates wear on the 2 strands where they emerge from the knot and bend at 90 degrees.
The rewoven Figure Eight puts wear at random points on the surface of the knot.

I agree, though, that toproping/lowering will probably wear the rope a lot more than pulling a rappel.

And that's why it's not an appropriate knot to join two ropes to climb on, or from which to be lowered. For descending (only), the EDK/flat-overhand will only see wear when it's pulled (... not under tension as in a toprope load).
Delhi Dog

Trad climber
Good Question...
Topic Author's Reply - May 12, 2010 - 02:07am PT
"Let's see ...

The original mistake was forgotten biner.

Then everyone runs amok in this thread going every which way how to rappel.

Good grief ...."


True WB, but what the overall discussion (IMHO) is about is possibly preventing the next "forgotten" thing.

Granted there is a lot of words, but I don't see a problem or issue with that...
If it makes even one person think a little deeper or influences a 2nd/3rd check at the rap station that's good...right?

Cheers,
DD
ps...and it is climbing related :0)


High Fructose Corn Spirit

Gym climber
Full Silos of Iowa
May 12, 2010 - 11:57am PT
Dr Sprock-

Dr. Sprock wrote on the companion thread-
"this was tragic but i am thinking it could have been worse.

if the first guy does not pull the knot, and the second guy does, then we could have lost both climbers. "

How so?


EDIT Ignore Brawny. His wisecracks are just part of his latest "social experiment." This thread's useful. It's already encouraged me to replace my old ATC.
Delhi Dog

Trad climber
Good Question...
Topic Author's Reply - May 12, 2010 - 12:29pm PT
...and in respect (because there would be varying opinions), I thought it would be worth keeping the discussion off the other thread...

Cheers,
DD
the Fet

climber
Tu-Tok-A-Nu-La
May 12, 2010 - 01:08pm PT
I would never top rope on a EDK. Top rope anchors and knots need to be among the most bomber setups because you can't keep an eye on them and they are under lots of movement. I could see an EDK being loosened during TRing and coming undone... scary.

I also cringe when I see people top roping on 2 quickdraws without locking biners on two different bolts. I always used two opposed biners when a rope disconnecting could mean a fall. Two non locking biners seperate from each other could unclip.
cleo

Social climber
Berkeley, CA
May 12, 2010 - 01:42pm PT
^^^ Ditto - toproping has lots more rope wear and jerking around of the setup, when you're out-of-sight, so having extra redundancy seems extra important.

I always use a double fisherman's (for TR) and an EDK (for rapping), but again, would like to hear more comments.


P.S. I like this thread too - I think it is important to review rappelling/TR techniques every so often, as I know I personally haven't thought of everything (that could go wrong).
rockermike

Trad climber
Berkeley
May 12, 2010 - 03:13pm PT
another trick; re: slobmasters second photo (and repeated by Clint), from the photo (rope through extended ATC, then down through lower biner attached to belay donut --- you can now clip a third biner into upper locker (blue one), then run the rope up back up and through this third biner; so rope goes through ATC, down to lower biner, back up through upper biner, then down to your hand. Your break is now downward, and the extra zig adds more breaking. Good for pig assisted rappels. I suppose you could even wrap around this loop even more times although I've never felt the need.
tradmanclimbs

Ice climber
Pomfert VT
May 12, 2010 - 03:22pm PT
All that sh#t is totally unnessicary. just add an extra biner to the normal place that you use a biner with the ATC. It doubbles or tripples your brakeing power.
rgold

Trad climber
Poughkeepsie, NY
May 12, 2010 - 03:22pm PT
RM, that is the method I described above. And TMC, doubling the biners isn't always enough, depending on rope thickness, coating, and amount of wear.

As for leaving an unconscious rappeller in place while you prussik up, assess injuries, and then do...something...a lot of time is going to go by, and suspension trauma is a serious issue, in addition to the fact that now someone else will be taking on a lot more risk. Unless the terrain is very slabby, my guess is the victim will almost always be better served by being lowered via the fireman-belay and gotten out of a hanging position.
Ghost

climber
A long way from where I started
May 12, 2010 - 03:38pm PT
RGold: what are you going to switch to now that the TRE is no longer being manufactured?

Maybe we should donate one to Mal at Trango and see if he can come up with something similar.
moronbros

Mountain climber
Seatte, North Cascades
May 12, 2010 - 03:57pm PT
There are some pretty simple bits of logic you can pull out of this discussion:

 When you are tired, make sure to check everything and add backups if needed.
 When you want to rap a full rope length and you only have a single rope, use a light retrieval line and a big knot at the top. rap a single strand.
 When your rope is frozen or wet, your friction devices (ATC, pusiks) will be affected.
 If you're lowering heavy stuff, add more friction.
 If you have no idea what you are doing and you find yourself at a rap anchor, get a good smart climbing partner.

Also to note:
 Talking at belays, although you might think that is fun, kills a few people here and there. Don't let it happen to you.
 Always test your rap with full body weight before disconnecting your personal anchor.

Rappelling is the perfect conversation to have when you want someone to really learn about tradeoffs.
tradmanclimbs

Ice climber
Pomfert VT
May 12, 2010 - 03:59pm PT
The few times i had a worn out atc and skinny ropes adding an extra biner seemed to just about bring me to a stop....
rgold

Trad climber
Poughkeepsie, NY
May 12, 2010 - 04:08pm PT
Ghost, I'm using the Petzl Reverso 3. It is a poor substitute for a non-worn TRE, but whaddya gonna do? I'd be happy to give Mal my TRE's; I sure wish someone would come up with something that really works well with half ropes.
Paul_in_Van

Trad climber
Near Squampton
May 12, 2010 - 04:20pm PT
Errr, Moronbros have you actually read any of this thread?

I hope for your sake that you have a smart climbing partner as you suggested...

P
Augie

Mountain climber
South Pasadena, CA
May 12, 2010 - 05:16pm PT
Re rap self-belays. I'm with in the below-the-device camp. Have used prusik above -the- device often over the years and it is prone to get stuck more often than an autoblock. But one thing u need to watch out for w/ the autoblock is it jamming against your rap device if you happen to take your brake hand off the rope while allowing the autoblock to hold your weight (if that happens, bye, bye). For this reason, I usually extend my device so that it's in front of me and can't touch my autoblock.

Only time I wouldn't use a self-belay is if you're rapping in a canyon near a waterfall or if you have to land in a hydralic. If you get caught in one of those situations with a stuck prusik or autoblock you could easily drown.

My 2 cents. Good discussion.
Dr.Sprock

Boulder climber
Sprocketville
May 12, 2010 - 10:31pm PT
i was thinkin that a big flat washer from the hardware store, probably about 39 cents, with a hole a bit bigger than the rope, maybe 1/8" thick, 3 inches round, you thread the rope thru, then tie whatever knot you want, it ain't gonna creep thru a hole that small and ruin your day.

make sure you camfer any sharp edges.

maybe make it 1/4" just in case.
moronbros

Mountain climber
Seatte, North Cascades
May 12, 2010 - 11:43pm PT
Hey Paul, care to prevent my untimely death by enlightening me on exactly what I'm going to kill myself with?

Just curious..
High Fructose Corn Spirit

Gym climber
Full Silos of Iowa
May 13, 2010 - 12:00am PT
Maybe there was a misinterpretation somewhere. Seemed like a fine synoposis to me. Now who's buying the drinks?

Hey, the Taco clock's about 6 minutes fast, what gives?
Dr.Sprock

Boulder climber
Sprocketville
May 13, 2010 - 12:46am PT
it's called Taco Time.

thats how long it takes to cook two jack tacos for 99, which i am going to munch on right now.

no, it's not dog food, just tastes like it,

so what if J Box is owned by ralston purina,

really, a very healthy food product consisting of soy meal and unsaturated lettuce.
Jay Wood

Trad climber
Fairfax, CA
May 17, 2010 - 12:06pm PT
Clint-

Re wear on EDK-

I rapped Royal Arches, w/ 2 ropes: 9.8, & 7.8 tied w/ EDK. 6 or 8 consecutive double rope raps

Result- very slight wear at 7.8 rope coming out of knot.

Will post pic.

I doubt I'll repeat with different knot, but can compare to a toprope w/ figure 8 at some point.
Jay Wood

Trad climber
Fairfax, CA
May 20, 2010 - 12:24pm PT

EDK w/ 9.8, 7.8mm ropes after Royal Arches rappel.

Very slight wear where 7.8 comes out of knot

No knot rolling

Insignificant knot creeping down from rap rings
HighTraverse

Trad climber
Bay Area
May 20, 2010 - 11:39pm PT
Always test your rap with full body weight before disconnecting your personal anchor.

An easy precaution to forget or ignore. But ignore at your own risk.

This isn't just about testing the anchor which you might be certain is bombproof.
It saves you from stepping back without your brake device secured to your harness. Which I almost did once. Would have certainly killed me.
david.yount

climber
May 21, 2010 - 09:22pm PT
Autoblock and Autolock are similar, yes. But are they the same? No, they are not.

Petzl Grigri, Trango Cinch, these are autolocking belay (rap) devices. Through their cam design they progressively pinch the rope as the rope travels sufficiently fast through the device.

A friction hitch tied to rappel ropes below the primary rappel device is an autoblocking hitch. I commonly see this rigging referred to as an autobloc. I’m not sure if the exact hitch used in indicated, but most everyone chooses to use a hitch that would be a Hedden or a Klemheist if they took the terminal bight and thread it thru the beginning bight. I do believe the exact hitch is indicated, but I have not searched for citing or references. Klemheist, Bachman, Hedden, Prusik, Clove, Garda, Munter these are all Hitches.

Kong Gigi, Petzl Reverso 3, Black Diamond ATC Guide, these belay / rappel devices can be rigged in autoblocking mode for belaying climber(s) following a pitch.

--

As rgold already shared, I remember a study I think was conducted by some from of national caving group interested in safety, they determined that a friction hitch was useless in preventing rappelling off the end of a rope(s). The volunteers, every one of them very experienced caver, only one person was successful, after several attempts, to let go of the friction hitch with their other hand when their braking hand felt the ends of the ropes go through.

Neither friction hitch rigging will help prevent rapping off the ends of the rope(s), whether fashioned above the primary rap device or fashioned below the primary rap device. But if your fancy is a hitch that is up rope of the primary rap device then consider the Klemheist Hitch. It has far superior sliding and braking characteristics than the Prusik Hitch.

--

If you want to prevent rapping off the end(s) then tie a stopper knot at the end of the rope. Typically a double overhand is used in each rope. If you are rapping on a 7mm you might consider a larger knot profile than the double overhand. If using a 6mm line then you need to consider a larger profile stopper knot than the double overhand.

And, unless you saddlebag your line(s) every time you rap with knots in the end(s), then there is a risk of an end being whipped by wind, up and over, and the stopper knot jamming in a crack. And that crack may be nearly impossible to reach; you can’t climb up to it, you cannot ascend your ropes back to the rap station and then rap down and over to the jam because the traverse angle is too flat.

If using two ropes tie a stopper knot near the end of each line, separately. As you rappel, often twists will be introduced into each line. These twists will be ushered to the ends. If the ends are free to move then most of these twists will exit the lines. Never tie the two ropes together, you risk massive twisting and knots. This is not trivial; you do want to think about how to prevent your ropes from twisting and forming random knots upon each other.

--

A carabiner brake rigged up rope from the primary rap device is far more comfortable then redirecting the brake lines thru a biner on the leg loop where now you need to raise the brake ropes to create more friction.

A carabiner brake has at minimum 3 biners. The attachment biner is recommended to be a locker. The frame biner is recommended to be a locker; and should really never be a wire gate non-locker. The brake bar biner may be most any style, but if it’s a large HMS shape it might not ride with stability. Or if it's a smaller biner than the frame biner then it may be more than challenging to rig it.

--

When rapping on two ropes using a Munter Hitch I run both ropes through a single large knot. I’ve tried using a separate biner for each line. I found the single biner and single knot worked better. Though, the details escape me. If using 2 biners they both must be on your harness (or belay loop). You can’t place 1 biner on a sling because unless you have arms 4-feet long you won’t be able to generate sufficient friction on that elevated biner because to rappel on a Munter Hitch you need to raise the brake line vertically above the biner.

--

david.yount

climber
May 21, 2010 - 09:24pm PT

I wanted to share my somewhat extended personal experience with using a very large washer as a blocking device to keep the joining knot between a thick rope and a very thin rope from jamming into rap rings, it also prevents pulling the joining knot through rap rings. But, I advise do not use a washer for this purpose.

Some words within this thread (not direct quotes):

The washer is simply a way to enlarge the effective outer diameter of the knot, so that it will not pass through the ring.

If I was rappelling all the way down the Nose from the top, and I knew rings were in place, I might take a (2" outer diameter) washer. It does have the advantage of preventing any part of a knot from going through the ring, and it can't be "untied".

--

My story:

I wanted the blocker washer system to work. It seemed ingenious and simple. I used it on many outings one year, involving dozens of rappels. I tried very thin metal washers (hard to find washers that are thin but also that large diameter), I tried washers with sufficiently small inner diameters that somewhat gripped the thick rope they were threaded on. I carried and experimented with several washers.

When you pull the rope, there is a chance the washer will slide off the end of the rope, in one of several ways. It served its purpose, you were kept safe while rappelling. But now you may be faced with additional rappels but you have lost your washer. The only solution is to carry as many washers as there are expected rappels.This is not a light solution; these washers have a lot of heft to them.

The most common way I have personally experienced washers sliding off the end of the thick rappel rope is when the washer sticks or jams against something as I’m pulling the thin line. The washer can get stuck or jammed quite lightly, but just enough that it sits still while I am pulling on the thin line and the thick line is pulling thru the fixed washer. If I am aware of this then I give a hearty flick to the pull rope to attempt to unstick the washer. But sometimes I cannot know the washer is fixed, it’s out of sight. It’s stuck, I don’t know that, I keep pulling the thin rope. The thick rope pulls thru. When the washer is fixed, rarely will it remain fixed, rarely will it remain on the mountain, rarely will it be lost with me never seeing it again. This happened to me once. One time the washer evidently got stuck and the thick rope pulled thru. I got the thick rope pulled down, but the washer was missing, it never came down. The other times the washer got stuck it also became unstuck. Sometimes it became unstuck for no reasonable ascertainable by me. Sometimes it became unstuck when the thick rope was free falling from it’s own weight. However the washer became unstuck I’ll tell you that it’s position on the thick line was close enough to the free end of the falling thick rope that often the washer that was stuck and then became unstuck is now dangerously close to sliding off the end of the thick rope. If my testing of this blocking washer system had occurred on vertical rock with no ledges I’m sure that the washer, when it became stuck and then unstuck, would have more often that not, ultimately slid off the end of the thick rope. The less than vertical rock and ledgey nature of the alpine routes I was climbing prevented the free end of the thick line from hanging vertically in space. If the thick line had hung down a vertical rock face after pulling, then the washer could easily slide down the vertical thick line, and the washer would slide off the end and the washer would free fall to the ground. By the way, that could make a dangerous projectile.

Well, I came to a direct and simple solution to the washer sliding off the rope. I would tie an overhand knot in the rap rope. Here was my updated system, beginning at the end of the rap rope. The end of the rap rope is tied to the pull line. Then there is a big washer. This washer prevents the joining knot from jamming into the rap rings, it prevents the joining knot from going thru the rap rings. Then there is an overhand knot. This knot secures the washer on the rap rope. Now there’s no way the washer will come off the rap rope.

Two problems sprung up. First was that overhand could partially jam in the rap rings. If the rap rings were sufficiently small (Metolius and another type I forget) andn the rap rope was sufficiently thick, then the overhand would partially jam in the rings. This jam would make it difficult to pull out when yanking on the thin line. But the real problem was far worse.

Further, the washer can jam or stick in suck as way to prevent the thick rap rope from being pulled further. The presence of the washer can jam your rap rope. When I never yet used this system, but just thought about it, I didn’t think the washer could be the cause of a jammed rope. I thought, hey, the washer is metal and metal slides across rock so easily, and the washer is round, and round things roll they don’t get stuck. I never foresaw a reasonable risk that the washer could ultimately jam my rope.

The washer can jam in a constricting crack the same way a round rock jams in a constricting crack. And the washer can jam in a vertical orientation which causes sufficient retention / friction on the rope that the rope cannot be pulled through the fixed washer. And if you use an overhand knot to captures the washer so that it can’t slide off the end of the rap rope, then this very same overhand will be the knot that fixes your rope when the washer changes basic nature from a safety device to a piece of pro in a crack.

I guess I’ll leave the washers on my bench in my garage, they’re not for rock climbing.



That being said, when I rappel using a thicker rope (like a 10mm single rope) and a much thinner rope (like a twin rope) or a thin pull line (7mm or 6mm accessory cord) I don’t enjoy using the heavily canyoneering tested rigging of a carabiner block (best to tie the clove hitch on the spine of the carabiner). I do use the carabiner block while canyoneering; it’s a standard for single line rappelling, and all of the anchors are equipped with Rapide Screw Links / Quick Links. Though, in the recent 3 years I’ve gotten into “ghosting” newer canyons so no webbing and Quick Links are left behind; nothing is left behind of our rappels in these canyons.

When I rappel on different sized lines I join them with a flat overhand. I then take the tail of the thinner line and tie an overhand around the thicker line. I squish this right up against the primary knot. I believe there were some tests, though likely not nearly enough, on this exact rigging? I always put the thick line through the anchors. I rap on both lines using a tuber device, like an Omega Pacific SBG-II. And then I rig a carabiner brake on the thin line. This carabiner brake is rigged up rope from my primary rap device.

I’ve used this exact system on 10mm main rope and using any one of 3 thinner lines: 6mm cord, 7mm cord or 7.4mm twin climbing rope. I’ve logged over 50 full length rappels on this system and never had any rope creepage. The extra friction offered by the carabiner brake on the thin line allowed me to rappel comfortably, I did not need to apply extra hand gripping force to the thinner line. The thin line did not creep upward. The joining knot did not creep into the rap rings.



But I gave up on 6mm pull lines. Always tangling itself, tangling in the main line, tangling on bushes, tangling on rock features, and wind causes havoc. As well, they wear out fast! First I got 65 meters of 6mm, and eventually the sheath looked hashed. So I bought another 6mm 65 meters long. When that sheath / cord wore out I switched to 7mm. Oh! Pulling was much less crappy with a 7mm compared with a 6mm. And my buddy’s 5mm I only agreed to use once, one day of rapping with his 5mm line and I told him I would never use that 5mm again; pulling is ridiculously stretchy and painful on the hands. But the 7mm still was not enjoyable. It tangled in all the same ways and was horrible in the wind. So I moved up to one of my 7.4mm Twin ropes. Behavior was better and I could use it to climb on by doubling it up.



Ultimately, I got a pair of Half Ropes 8.4mm in 1998 and that’s all I climb on. It’s been 12 years of no fooling around. Two ropes for increased safety in falls over sharp edges. Two ropes to easily mitigate rope drag on wandering alpine and crag routes. Two ropes to increase safety for the follower on traversing sections that are followed by a vertical section. Two ropes for full length rappels. Two ropes for increased safety in case rockfall cuts one rope.


Clint Cummins

Trad climber
SF Bay area, CA
May 23, 2010 - 11:25pm PT
Thanks, Jay - it looks good.
janeclimber

Ice climber
May 25, 2010 - 02:08pm PT
Hey, David,

Could you please elaborate on the carabiner brake you mentioned in your earlier post? It would be super nice if you can post a photo of your set up. Thanks!-Jane

"When I rappel on different sized lines I join them with a flat overhand. I then take the tail of the thinner line and tie an overhand around the thicker line. I squish this right up against the primary knot. I believe there were some tests, though likely not nearly enough, on this exact rigging? I always put the thick line through the anchors. I rap on both lines using a tuber device, like an Omega Pacific SBG-II. And then I rig a carabiner brake on the thin line. This carabiner brake is rigged up rope from my primary rap device."

david.yount

climber
May 26, 2010 - 04:57am PT
Jane, both the thin line and the thick line are rigged into my rappel device. Ask if this is not clear. My right hand is my brake hand, it holds both ropes and controls my rate of descent. I also clip a 2-foot sling to my belay / rappel loop on my harness. I clip a carabiner brake to this sling. The carabiner brake is rigged onto the thin line. The carabiner brake rides on the thin rope about 1-foot vertically above my rappel device.

The carabiner brake creates a mild amount of friction on the thin rope. In my experience I have found that this additional friction on the thin rope prevents the thin rope from slipping through the rappel device faster than the thick rope. The carabiner brake prevents the thin rope from creeping relative to the thick rope. My brake hand holds on to the 2 ropes normally and adjusts rate of descent normally. I don't pay special attention to grabbing the thin rope with greater force than the thick rope.

I hope this helps; I'm not the type to create demonstrations, take photos, and then post the photos.
clifff

Mountain climber
golden, rollin hills of California
Jan 3, 2016 - 05:30pm PT
Here's a super way to tie an EDK - the Double Overhand Knot _ check crasic's post:

http://www.supertopo.com/climbers-forum/1904819/Rappelling-knot-for-different-diameter-ropes

It's about a million times better than the simple overhand knot of the traditional EDK. If you examine it carefully you can see that it can be tied 2 different ways. The same topology but the working ends are switched. I don't know which is best.

photo - crasic
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