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D'Wolf
climber
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May 10, 2010 - 12:00pm PT
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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
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Delhi Dog
Trad climber
Good Question...
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Topic Author's Reply - May 10, 2010 - 12:07pm PT
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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
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D'Wolf
climber
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May 10, 2010 - 12:12pm PT
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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
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tradmanclimbs
Ice climber
Pomfert VT
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May 10, 2010 - 12:19pm PT
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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...
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Reilly
Mountain climber
The Other Monrovia- CA
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May 10, 2010 - 12:34pm PT
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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.
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ontheedgeandscaredtodeath
Trad climber
San Francisco, Ca
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May 10, 2010 - 12:58pm PT
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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.
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D'Wolf
climber
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May 10, 2010 - 01:09pm PT
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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
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David Wilson
climber
CA
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May 10, 2010 - 01:13pm PT
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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.
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tradmanclimbs
Ice climber
Pomfert VT
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May 10, 2010 - 01:13pm PT
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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.
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D'Wolf
climber
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May 10, 2010 - 01:34pm PT
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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
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Chiloe
Trad climber
Lee, NH
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May 10, 2010 - 01:34pm PT
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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.
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HighTraverse
Trad climber
Bay Area
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May 10, 2010 - 01:36pm PT
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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.
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HighTraverse
Trad climber
Bay Area
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May 10, 2010 - 01:45pm PT
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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.
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rectorsquid
climber
Lake Tahoe
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May 10, 2010 - 01:46pm PT
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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
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cleo
Social climber
Berkeley, CA
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May 10, 2010 - 01:50pm PT
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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.
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Ken M
Mountain climber
Los Angeles, Ca
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May 10, 2010 - 02:02pm PT
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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
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wbw
climber
'cross the great divide
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May 10, 2010 - 02:38pm PT
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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.
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Auto-X Fil
Mountain climber
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May 10, 2010 - 03:00pm PT
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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.
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Mighty Hiker
climber
Vancouver, B.C.
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May 10, 2010 - 03:03pm PT
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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.
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Chiloe
Trad climber
Lee, NH
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May 10, 2010 - 03:08pm PT
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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.
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