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andrewbanandrew
Dec 16, 2007, 12:23 AM
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I know this question has been addressed time and time again but I just finished reading some books and I'm confused.
Let's presume that the anchor is redundant and bombproof and you've rigged a cordalette or equalette or whatever the hell ends up with a single attachment point.
John Long says not to tie into the anchor using a clove hitch on the rope because clove hitches slip at relatively low forces (1000 lbf).
However, I've read here that many people prefer the clove hitch for a number of reasons (simplicity, uses less rope, adjustability, can be tied one-handed). And I'm staring at a diagram of a belayer in the book Mountaineering: FOTH, and he's tied in with a clove hitch, and this study (albeit not exactly statistically comprehensive) demonstrates that clove hitches don't slip or fail until 10 kN: http://web.archive.org/web/20030924042940/http://www.c2safety.com/Pdf+filer/test+knopar.pdf
So what gives? What's right and what's wrong?
Some have written here that they use a clove-hitch, but then back it up with a figure 8. Doesn't that pretty much kill all the advantages of using the clove hitch except the adjustability part? I'm trying to picture it in my head but I think you'd have to tie two figure 8s to back up a clove hitch (see attachment).
I guess this setup is faster than tying a figure 8 with another figure 8 backup...
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jp_sucks
Dec 16, 2007, 12:46 AM
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Clove hitch is fine, no need for a "back up 8". This method is accepted by the ACMG/AMGA/UIAGM as a standard and safe way to anchor yourself.
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fulton
Dec 16, 2007, 1:30 AM
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andrewbanandrew wrote: Let's presume that the anchor is redundant and bombproof and you've rigged a cordalette or equalette or whatever the hell ends up with a single attachment point.
about that...
The cordellete has both a power-point as well as diffrent attatchment options on the shelf... the single attatchment point is actually a short comming of the "equallete" (and one of a million reasons that this "equallete" invention has limmited practicality).
In reply to: Some have written here that they use a clove-hitch, but then back it up with a figure 8. Doesn't that pretty much kill all the advantages of using the clove hitch except the adjustability part?
Ok, so at a hanging belay:
I clove hitch myself into the anchor, then
I tie a figure eight about five or six feet down.
This gives me a perfect loop to stack the rope on, and
the stack shifts under you whenever you move around so it doesn't tangle.
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el_layclimber
Dec 16, 2007, 1:34 AM
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Just make sure you have a knife in case you have to cut the rope.
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rgold
Dec 16, 2007, 2:58 AM
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The Lyons tests were slow-pull tests and suggested that, under these conditions, clove hitches do not slip in dynamic rope but may slip in low-stretch ropes. Because of this, they shouldn't be used in static ropes without solid backups.
Some years ago Adam Fox conducted or had conducted for him tests that concluded the clove hitch slipped around 1000 lbf. When asked repeatedly on this site for data backing up his claim that not only these tests, but many others confirmed this result, he was unable to provide either data or references, so it is hard to know how reliable that information is.
Sterlingjim conducted drop tests with dynamic rope and got different results from the Lyons slow-pull tests. The post is over at NE Climbs. I think it was Knudenoggin who pointed it out to me.
When the clove hitch was the knot used to attach the rope to the dropped weight, it slipped completely and untied. When the clove hitch was used at the other end in the position it would be in an anchor, it held 5 UIAA+ falls before the test was stopped.
Here is a relevant excerpt from that post:
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"First three tests performed on same sample of 10.2mm dynamic rope. All knots and or hitches were untied and retied for each test. Rope and knots pretensioned as per UIAA 101 (loaded with 80kg for 1 min). For the sake of simplicity the clove hitch was tied to the mass in place of the usual figure of 8 or overhand follow through.
First test: Clove hitch with 12cm tail and no backup. 80kg mass, fall factor 1.71, peak impact force 4,8kN. Hitch slipped completely, bye bye.
Second test: Clove hitch with 20cm tail and no backup. 80kg mass, fall factor 1.71, peak impact force 5.05kN. Hitch slipped completely, mass was released and fell to ground, adios.
Third test: Clove hitch with 3cm to double overhand backup to limit slippage 80kg mass, fall factor 1.71, peak impact force 9.59kN. Hitch held, backup knot jammed to clove hitch, hitch welded (literally) and not able to untie.
Fourth test: I tried to simulate a more realistic climbing scenario where the leader would take a high fall factor of 1.81kN (not all that realistic but perhaps worst case scenario). Rope was attached to the mass with figure of 8 then to a clove hitch to the frame and then a figure of 8 to another part of the frame . Sounds weird I know but trust me it simulates what is being discussed in this thread pretty well. The force was not falling directly onto the clove hitch but was pretty damn close. I also used a fresh rope sample for this one. The results: 80Kg mass, fall factor 1.81, peak impact force 8.77kN. Hitch held 5 falls before I stopped the test. Judging from the impact forces on the 4th and 5th drops I would predict the rope to fail within the next one to three drops."
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It isn't entirely clear to me what to make of these results, other than the fact that you definitely don't want to tie in with the rope clove-hitched without backup to a locker on your harness, a practice that has not yet shown signs of popularity. (You don't want to use this way with a backup either, if you want to untie it after a major fall.) In the anchor configuration test, the clove hitch did not slip. Nonetheless, these tests do show that clove hitches can slip under extreme dynamic loading.
Personally, I almost never use anchors with master points, so I always have two to four clove hitches between me and oblivion, and frankly, I ain't worried the knots going. If you use cordelettes or other master-point creating systems, it is certainly easy enough to clip a figure-eight backup into the master point (I don't see how this negates the utility of the clove hitch), or perhaps even more simply just tie a second clove hitch in series with the first to one of the anchor pieces. Yet another option, if you don't mind doubling the length of rope used for tying in, is to clip the anchor rope to the master point but then clove hitch it back to the belay loop and climbing tie-in loop at the harness. This way the clove hitch only gets about half the total impact.
Personally, I've never had any trouble untying a clove hitch in forty years of use in climbing situations, including once when it had to bear the brunt of a factor-2 fall directly onto the belay (no slippage there either, by the way, at least none that was noticeable afterwards). Remember that the figure-8 is already notorious for being hard to untie after being loaded.
The clove hitch is not a "no-brainer" knot. (But perhaps there are no "no-brainer knots...) There are two ways to orient it on the biner relative to the load strand, one of which puts the load strand a distance out from the spine of the carabiner and so will contribute to a carabiner breaking strength below the official rating. Users of the clove hitch should learn to automatically tie it the right way every time.
(This post was edited by rgold on Dec 16, 2007, 6:10 PM)
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ja1484
Dec 16, 2007, 3:18 AM
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andrewbanandrew wrote: John Long says not to tie into the anchor using a clove hitch on the rope because clove hitches slip at relatively low forces (1000 lbf).
Yer reading out of date books. Climbing anchors 2nd ed. Long clearly states clove hitches do not slip in nylon cordage. Evidence is mounting that clove hitches may not slip in tech webbing either, or that it only does so at extremely high loads.
Edit: As rgold states above, this is when you use the clove hitch to attach something to an anchor, and that something has already been secured to the rope with another knot.
Preferred primary anchor into a belay is a clove hitch or bite8 on the powerpoint - I prefer a clove for adjustability, sometimes using a purcell prusik as a second method to adjust my attitude to the anchor.
(This post was edited by ja1484 on Dec 20, 2007, 4:32 AM)
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ja1484
Dec 16, 2007, 5:06 AM
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fulton wrote: about that... The cordellete has both a power-point as well as diffrent attatchment options on the shelf... the single attatchment point is actually a short comming of the "equallete" (and one of a million reasons that this "equallete" invention has limmited practicality).
Someone's really behind the times.
Three strand powerpoint for the equallette gives you plenty of attachment options, and if the anchor is two piece or three piece, the number of attachment areas literally explodes. Off the top of my head, if you use it on a three piece anchor, you have a minimum of three redundant attachment points, and at a two point (i.e. bolted) anchor, you're looking at a minimum of four. Even on a four piece anchor, you've still got two redundant (but overlapping) attachment points at the powerpoint.
I have yet to see any situation where an equallette was less versatile than a cordellette - only situations where people are having trouble adjusting their thought process from what their habits have become. I'm open to input though.
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tytonic
Dec 16, 2007, 7:06 AM
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Here are the words straight from Long's book.
"A tie-in knot that is quick and easy to tie, easy to adjust for length once tied, and that unties easily is naturally a knot welcomed by climbers. The clove hitch is such an knot. Some climbers believe the trade-off for all this utility is that the clove hitches reportedly slip at around 1,000 pounds of load, although tests have shown that a clove hitch will in fact not slip in a dynamic rope . . ." (Long J, Gaines B. Climbing Anchors, 2nd Edition. 2006. p. 121)
Like others have said above, John Long goes on to say that the clove hitch has slipped when tested in static ropes and includes a few other common sense warnings.
Sounds like to me tying in with a clove hitch is fine.
Edited: A clove hitch is ok for tying into the anchor. Obviously, its not ok for tying the rope to your harness.
(This post was edited by tytonic on Dec 16, 2007, 7:31 AM)
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evanwish
Dec 16, 2007, 10:11 PM
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just get a pre-sewn chord [i use spectra], tie it to your harness with a girth hitch through the two tie in points, clip that onto the anchor
or better yet, get the metolious PAS
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Jbitz
Dec 17, 2007, 1:55 AM
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A clove will work well for tying yourself in. Some people backup with an eight or some sort of PAS/slings to add redundancy.
I will try to describe in some detail what I like to see generally or what I am ok with personally. There are many ways to do things and one method doesn't necessarily fit all situations so one needs to be flexible.
My advice is to keep it simple if you can. There is nothing like coming up to a belay station as a second and thinking to yourself, "What they hell is that mess and where am I supposed to clip into?"
Ok, the rope tied to your harness runs to a locker at your masterpoint or shelf to which you have it clove-hitched or tied with an eight.
Now if you want to back it up here are a couple ways you can do it. The rope can either be attached back to your harness with a locker as backup or tied again to another locker on your anchor system using a backup knot whether it be an eight or another clove. A PAS/sling with locker could be used also.
The rope then runs through your belay device to your second. A direct belay from your anchors is usually preferred as opposed to being off your harness for a bomber belay anchor setup as you described.
Just out of curiosity what belay device do you typically use or are planning to use to bring up your second?
(This post was edited by Jbitz on Dec 17, 2007, 1:59 AM)
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diebetes
Dec 17, 2007, 2:25 AM
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evanwish wrote: just get a pre-sewn chord [i use spectra], tie it to your harness with a girth hitch through the two tie in points, clip that onto the anchor or better yet, get the metolious PAS
The shortcomings of this technique:
1. extra gear that you might forget (as long as you don't forget to tie in, the only thing you can forget to bring with you is a locker)
2. the rope is dynamic. Spectra certainly isn't
3. if you climb with that sling girth hitched to your harness, it's more to get caught as you climb
4. you're already tied into the rope!
I would encourage everyone to tie in to the anchor with the climbing rope.
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rgold
Dec 17, 2007, 2:35 AM
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In reply to: just get a pre-sewn chord [i use spectra], tie it to your harness with a girth hitch through the two tie in points, clip that onto the anchor or better yet, get the metolious PAS
Neither method is a good idea for attaching a belayer, especially one who will be belaying the leader. These slings transmit all the force on the belayer to the belay anchor. Tying in with the rope gives a dynamic connection capable of absorbing some impact energy. When the anchors are less than perfect (and climbers don't always know when this is the case) the additional protection of an energy-absorbing connection could be important.
A further problem is that both spectra slings and the Metolius PAS can break under a factor-2 fall. If the belayer is tied in short and steps up a bit to adjust something, such a fall could ensue.
The clincher is that these critical drawbacks are not balanced by any significant convenience. The rope with clove hitch is far more versatile and adjustable than either a fixed-length sling or a PAS.
This is not to say that dedicated tethers do not have their uses. For free climbing as opposed to aid uses, the Sterling Chain Reactor is an alternative than the PAS that won't break under a factor-2 fall.
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evanwish
Dec 17, 2007, 3:35 AM
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rgold wrote: In reply to: just get a pre-sewn chord [i use spectra], tie it to your harness with a girth hitch through the two tie in points, clip that onto the anchor or better yet, get the metolious PAS Neither method is a good idea for attaching a belayer, especially one who will be belaying the leader. These slings transmit all the force on the belayer to the belay anchor. Tying in with the rope gives a dynamic connection capable of absorbing some impact energy. When the anchors are less than perfect (and climbers don't always know when this is the case) the additional protection of an energy-absorbing connection could be important. A further problem is that both spectra slings and the Metolius PAS can break under a factor-2 fall. If the belayer is tied in short and steps up a bit to adjust something, such a fall could ensue. The clincher is that these critical drawbacks are not balanced by any significant convenience. The rope with clove hitch is far more versatile and adjustable than either a fixed-length sling or a PAS. This is not to say that dedicated tethers do not have their uses. For free climbing as opposed to aid uses, the Sterling Chain Reactor is an alternative than the PAS that won't break under a factor-2 fall.
huhh interesting. It seems to be a really popular thing to do.
In fact that's the girthhitched sling way i've seen it done out on the crag
I always find it convenient because you just clip it into the anchor with your one free hand.
I also generally belay the second up with a grigri or reverso attached to the masterpoint...
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wallace
Dec 17, 2007, 4:06 AM
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There's a nice tech tip from Climbing for this in order to save time, but I can't find it...it involves the OP's set up with a bomber anchor -
Leader belays second up with device using autoblock mode - once second reaches station then s/he weights the rope, activating autoblock and is tied off (on the other side of the device - there's your backup). Quick gear swap, old leader takes new leader's belay device and puts new leader on belay. New leader removes autoblock and tie off and leads.
It's quick, and as long as your anchor is good (so you're happy to hang your weight off the anchor and use the autoblock) then it works well.
I've not seen this discussed here and would like to see what the "old heads" have to say.
andy
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photoguy190
Dec 17, 2007, 4:22 AM
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I've always used the girth hitched method as well, I was wondering with the the tie in method what if you have more then one or two people at the belay stations, how does this work with rope management.
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TheDullEnd
Dec 17, 2007, 5:26 AM
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I've always used a PAS- if I feel like I need redundancy I'll back it up with a clove hitch.
I don't feel like all of the force of a lead fall will be put directly onto the anchor- I'm a pretty stout guy and a lot of the force will get absorbed by my upward movement. It's rare that I'm clipped in so short that there wouldn't be much room for me to provide give.
The clove hitch is definitely a great way to go though, I usually just tend to go with the PAS because of its expediency.
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majid_sabet
Dec 17, 2007, 6:02 AM
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All climbing anchors, regardless of how you will use them should be build to handle FF2 or forces above 20 KN.
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fresh
Dec 17, 2007, 10:13 AM
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evanwish wrote: just get a pre-sewn chord [i use spectra], tie it to your harness with a girth hitch through the two tie in points, clip that onto the anchor or better yet, get the metolious PAS
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csproul
Dec 17, 2007, 2:14 PM
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TheDullEnd wrote: I've always used a PAS- if I feel like I need redundancy I'll back it up with a clove hitch. I don't feel like all of the force of a lead fall will be put directly onto the anchor- I'm a pretty stout guy and a lot of the force will get absorbed by my upward movement. It's rare that I'm clipped in so short that there wouldn't be much room for me to provide give. The clove hitch is definitely a great way to go though, I usually just tend to go with the PAS because of its expediency.
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evanwish
Dec 17, 2007, 9:40 PM
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I generally carry 2 long slings for anchoring. one for top and the other for the bottom. a 30' and a 40'
that's allot of dynamic streach
I usually do a 3 or 4 point anchor but having the extra length always prepares me for anything like slinging a lage block or tree past the top of a climb.
if the lead climber clips the masterpoint as a piece of pro (yeah yeah FF2...) wouldn't that 40' of dynamic 7mm chord be enough to reduce the force?
asuming your tied in with a PAS
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csproul
Dec 17, 2007, 10:00 PM
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evanwish wrote: I generally carry 2 long slings for anchoring. one for top and the other for the bottom. a 30' and a 40' that's allot of dynamic streach I usually do a 3 or 4 point anchor but having the extra length always prepares me for anything like slinging a lage block or tree past the top of a climb.
if the lead climber clips the masterpoint as a piece of pro (yeah yeah FF2...) wouldn't that 40' of dynamic 7mm chord be enough to reduce the force? asuming your tied in with a PAS
(This post was edited by csproul on Dec 17, 2007, 10:02 PM)
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evanwish
Dec 17, 2007, 10:49 PM
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csproul wrote: evanwish wrote: I generally carry 2 long slings for anchoring. one for top and the other for the bottom. a 30' and a 40' that's allot of dynamic streach I usually do a 3 or 4 point anchor but having the extra length always prepares me for anything like slinging a lage block or tree past the top of a climb.
if the lead climber clips the masterpoint as a piece of pro (yeah yeah FF2...) wouldn't that 40' of dynamic 7mm chord be enough to reduce the force? asuming your tied in with a PAS I'm not going to pretend I know the physics behind what you're saying...and I'm not even really all that clear on what it is you are saying. I certianly don't see how using a 40 foot or 40 inch (btw ' denotes feet, and " denotes inches) sling is going to introduce any dynamic stretch and reduce any force. But, that said, I don't really see any reason to cip into the belay with anything other than the rope. It's adjustable, plenty strong enough, dynamic, requires me to carry nothing extra, and if needed a clove hitch can be tied easily with one hand. The only time I clip in with a sling is when I can't use the rope, like when setting up rapels. RGold pretty much said anyhting you need to know in his post above.
yeah i said 40 feet. I find it really convenient on trad routes when topping out, or extending a belay..
i see what you're all saying, it's easy when you have a good stance but as much as i try i just can't tie in like that while hanging on and clipping into a hanging belay. (that's why i've always resorted to just clipping in...)
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majid_sabet
Dec 18, 2007, 7:50 AM
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Evan
If you look at most biners, you will see two different ratings. One with gate closed and the other one with gate open. Generally, a biner with an open gate has a lower breaking strength by some 50%.
Now, let's say you are trad climbing and you placed four draws but three of them are facing the rock, what happens if you fall, biner hits the rock and those gate stay open?
http://www.rockclimbing.com/.../Traver_s_94518.html
(This post was edited by majid_sabet on Dec 18, 2007, 7:52 AM)
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evanwish
Dec 18, 2007, 4:04 PM
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so then the question comes to "who do you trust?"
I've seen guys who are guides and climb all over the world, Alaska to the Antartic and they all use the girth hitched tether.
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