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sittingduck
Jun 2, 2006, 11:49 PM
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I posted this in the 60 page discussion about the "sliding X", afraid it drowned there. Since this is my solution to the "John Long anchor challenge" I'd like to hear the RC community opinion on this method.
Method: (knots and other details not explained, if you lead trad you should know them already)
1. place pro, at least two of the pieces should be totally independent.
2. clip a cordalette into each piece and pull the cord down between each piece and clip all the loops with a screw gate. (clip it as explained elsewhere on RC.com)
3. do not make any knots on the cordalette, no fig 8 or stopper knots
4. tie your climbing rope(s) to the screw gate at the appropriate length
5. continue the rope up to the piece of pro that you think is most bomber and tie a clove hitch on its biner.
6. leave just enough slack in the rope(s) between the screw gate and the bomber piece so that the cordalette can move freely to take load in all directions that is reasonable in case of a fall into the anchor (factor 2).
7. clove hitch the rest of the pieces in the belay so that the climbing rope(s) is tied into all the pieces
8. (not mandatory) I try to set a piece of pro a bit higher than the belay so that I have the rope coming from above when bringing up the second. This piece will be the seconds first piece when she starts to lead the next pitch
9. pull up the slack and attach the rope to your belay device and clip it into your harness belay loop with a screw gate biner.
10. bring up the second.
11. when the second is up, use the appropriate knot to tie of your belay device while she gets sorted to start the next pitch.
Why use this method?
It is as safe as the pro placed
It is redundant
It is easy (KISS)
It distributes force perfectly across the pieces
It uses no static components
It works with any number of pieces
It requires no new gear
It requires no new knots
I know some will react on the fact that there will be shock load on the anchor if one of the pieces blows or the cordalette breaks. So what? According to testing done by members of the RC community shock load is no big danger on a dynamic system.
If one piece blows the cordalette has taken the peak force of the fall and the climbing rope used for redundancy will take the rest.
Any reason not to use this method?
http://www.home.no/sittingduck/tegning.gif
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mr8615
Jun 2, 2006, 11:58 PM
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Depending on your anchor, sounds like it'd take a lot of your climbing rope. I've been on some pitches where I barely had 3 feet to spare, not to mention the amount you're describing. Otherwise, it sounds like it could do the job. Might get a bit crowded/clustered though. I like to keep the climbing rope separate from the anchor system, but couldn't you achieve the same thing with two lengths of static line (I feel like someone else raised that idea, two cordalettes, one cloved, the other sliding x style). I know, I know, extra gear, I'm not recommending it or doing it.
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sittingduck
Jun 3, 2006, 12:17 AM
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@mr8615, jepp, good point, if the rope is streached the method is impossible to use. I use two 60 meter ropes and always seems to have enough. Have used this method with a fig 8 knot on the cordalette up until now.
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jschwartzel
Jun 3, 2006, 1:23 AM
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Which other members of the rock climbing community have done test that "eliminate" the danger of shock loading in a "dynamic" system? Maybe they should consider that if an anchor fails you are dead and so is your partner. I would not want to trust even my most bomber piece in the anchor to a shock load. It probably won't be the second coming up the pitch that will do it but that sketchy start of the second pitch when you fall, land ON your belayer/partner, you both go sailing, the load rips a piece, then shock loads the works, and........ you're dead. There ain't much dynamics in a lead rope that is only 8 to 10' out. Just a thought.
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bandycoot
Jun 3, 2006, 3:03 AM
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I like your idea of integrating both the equalization of two pieces and the dynamic nature of the climbing rope into the rest of the anchor. As it is, I'm a huge fan of the idea that each anchor requires something different to be sufficient, but I'll definitely keep your anchor idea in mind when I find it appropriate. Keep up the good brainwork!
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moose_droppings
Jun 3, 2006, 3:55 AM
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In reply to: It distributes force perfectly across the pieces
You might catch some flak on that statement, there was a lot of discussion on the equalizing of pieces with different biners, material, etc.. Perfect equalization seems to be quite hard(if not impossible) to achieve. I have no problem with say, 3 pieces bearing unequal 35%-25%-40% load. Your idea(aside from using a lot of rope) would work fine for me.
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dominic7
Jun 3, 2006, 4:58 AM
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So you are clove hitching the rope and the cordalette to all the biners on the pro? I see a couple of issues with this. One, how does your second tie in when they arrive at the anchor? Are they piling clove hitches onto the biners as well? Second, when the leader goes to leave on the next pitch you need to open those biners to get your clove hitch out? This is a dodgy practice in my humble opinion. I think that once the anchor is set up, you shouldn't be mucking with it by opening component biners while it is the only thing keeping you alive. Finally (and somewhat unrelated), top belaying a second off your harness without a redirect through the anchor can be dangerous in certain situations. A week or so ago I saw a kid get pulled off a ledge by his second taking an unexpected fall while cleaning. He only fell a few feet and managed to hold onto his belay as he crashed and banged around, but it was scary looking. Better to use some sort of auto-locking device right on the anchor like a Gri-Gri or Reverso. Or redirect a harness belay through the anchor so you get pulled up instead of down.
I miss the sliding x thread. It was pretty cool. :)
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sittingduck
Jun 3, 2006, 9:11 PM
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In reply to: jschwartzel Which other members of the rock climbing community have done test that "eliminate" the danger of shock loading in a "dynamic" system?
In reply to: bandycoot I like your idea of integrating both the equalization of two pieces and the dynamic nature of the climbing rope into the rest of the anchor. As it is, I'm a huge fan of the idea that each anchor requires something different to be sufficient, but I'll definitely keep your anchor idea in mind when I find it appropriate.
In reply to: moose_droppings Quote: It distributes force perfectly across the pieces You might catch some flak on that statement, there was a lot of discussion on the equalizing of pieces with different biners, material, etc.. Perfect equalization seems to be quite hard(if not impossible) to achieve. I have no problem with say, 3 pieces bearing unequal 35%-25%-40% load. Your idea(aside from using a lot of rope) would work fine for me.
You are right, it is "perfect", not perfect. Close enough for me to live with. As for the amount of rope, give it a try.
In reply to: dominic7 So you are clove hitching the rope and the cordalette to all the biners on the pro?
Terrible drawing:
http://www.home.no/.../redundantanchor.gif
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charlesjmm
Jun 4, 2006, 2:50 PM
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Sittingduck, that´s a nice idea of backing up the sliding X with the rope. I offer you some comments :
http://i49.photobucket.com/...idingXRopeBackup.jpg
1) A 3 points sliding x alone provides far from perfect equalization. Although it will start with a 33%-33%-33% (theoretical) type load distribution, it is hard to predict its behavior afterwards due to the substantial friction present at the biners. However, your setup aggravates friction problems at the placements even further as the cordelette encounters additional friction introduced by the clove hitched rope.
2) In a 3 points anchor, failure of the middle piece will produce load multiplication on the outer pieces due to the broad angle resulting between them (see right picture).
3) I observe frequent biner crossloading when a placement fails produced by the climbing rope pulling upwards and the cordelette pulling downwards on the failed biner.
CharlesJMM
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slimper
Jun 4, 2006, 4:32 PM
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:D Thanks for the pictures :D
Great problem solving! It would be interesting to know how much the friction on the cordalette would effect the percentage of weight distributed to each piece. Would it be better to put the clove from the rope on the top or the bottom of the biner? It seems that depending on which piece fails this could potentially cause the biner to be loaded it's gate axis. Example, the middle piece blows and the rope is tied on the bottom of the biner. as the rope pulls tight and pulls from the bottom of the biner it could twist the biner so the gate is facing down. causing the cordolette to fall directly on the gate.
Also, in a anchor system like this would you put in a multi-directional piece (Gear so the belayer doesn't fly above the anchor) into the anchor or straight onto the belayer?
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sittingduck
Jun 4, 2006, 6:08 PM
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Thanks for the comments CharlesJMM.
Yes the sliding X three point does not distribute perfectly, sorry. But it does distribute force to all the pieces and I am happy that I can use a ultra simple method to achieve it.
I do not climb trad with one rope and did not foresee that the sliding x would produce load multiplication in the one rope scenario. Clove hitching the middle piece, the left one and the right one works, consuming a bit more rope. The climbing rope will catch the middle piece if the left or right piece blows, if the middle piece blows the next in line will take the force, which is the basic idea in this method. Cross loading the blown biner is no subject since it doesn't hold any weight anymore. Using two ropes eliminates this problem and allows for clove hitching all the pieces, one rope one piece and the other rope two pieces.
The idea is that if one piece or the sliding x fails, then it has done its job and the climbing rope(s) should take the rest of the force, sounds like a silly method but is it?
@slimper
In my head the belay anchor should be constructed to take a factor two fall, wich is the only fall you'll get on a belay anchor. The other concern is preventing the belayer to be janked high if the leader falls after placing pro en route, a directional piece to prevent this is a good implementation in any method.
The theory, yes it is theory, is that the sliding x will distribute force to all the pieces in the anchor. If nothing blows everything is fine. If one piece blows then the remaining force should be well below F2 and the dynamic climbing rope should arrest any force left, on one piece. If this also blows there is one piece left, also clove hitced to the climbing rope. If this fails I might get lucky to get saved by my directional piece, or die. By the way, the climbing rope clove hitched to a biner holds a F2 fall, ripping the sheat but not the core, done that.
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charlesjmm
Jun 5, 2006, 6:28 PM
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Sittingduck, if you want your anchor design to provide better load balancing qualities, you could consider an alternative way of using the cordelette. It will only require an additional biner.
http://i49.photobucket.com/...sjmm/WRopeBackup.jpg
I did not illustrate to rope backup as it clutters the underlying idea.
You will notice a huge improvement in equalization.
CharlesJMM
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hugepedro
Jun 5, 2006, 9:11 PM
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Like the rigs in that sliding x thread, this rig is more complicated than it needs to be, therefore it is not KISS. The rig I use requires zero tying of knots, I just clip the pieces and clip the power point and I'm done.
In reply to: I know some will react on the fact that there will be shock load on the anchor if one of the pieces blows or the cordalette breaks. So what? According to testing done by members of the RC community shock load is no big danger on a dynamic system. If one piece blows the cordalette has taken the peak force of the fall and the climbing rope used for redundancy will take the rest. Any reason not to use this method?
What the testing determined is that extension is "no big danger" if it is limited. Your rig can allow some major extension. If your "most bomber" piece fails first you will have big extension on the remaining 2. If 1 of those 2 fails first all the load will fall on 1 piece, and if that piece fails you will have huge extension on your last piece.
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fitzontherocks
Jun 5, 2006, 10:09 PM
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Charlesjmm, it looks like you're going from 3X the strength of a single strand of cordelette to 2X the strength (from three loops to two loops). Is that right? On 5-7mm accessory cord, that makes me a little nervous. Anyone else? Also, the fisherman's knot in my cordelette is pretty dang tight. I'd hate to have to fumble with undoing it at a belay (and then retying it later). But maybe I'm just not getting it.
(Actually, lately I've been using this 13' Wild Country Belay Sling/Cordelette lately-- http://www.gearexpress.biz/Merchant2/merchant.mv?Screen=PROD&Store_Code=G&Product_Code=22DS10400 -- and digging it. But there's no untying it! )
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dutyje
Jun 5, 2006, 10:11 PM
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In reply to: Sittingduck, if you want your anchor design to provide better load balancing qualities, you could consider an alternative way of using the cordelette. It will only require an additional biner. http://i49.photobucket.com/...sjmm/WRopeBackup.jpg I did not illustrate to rope backup as it clutters the underlying idea. You will notice a huge improvement in equalization. CharlesJMM
Now, for a final magic trick, cut any one leg in your equalized cordalette. Your entire anchor fails.
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sittingduck
Jun 5, 2006, 10:58 PM
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CharlesJMM, again thanks, really appreciated.
Before this gets complicated, do you think it is safe to use the climbing rope(s) clove hitched to the pieces for redundancy as the underlying idea, allowing the equalizer to shock load the anchor if one piece blows?
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dutyje
Jun 6, 2006, 12:10 AM
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In reply to: CharlesJMM, again thanks, really appreciated. Before this gets complicated, do you think it is safe to use the climbing rope(s) clove hitched to the pieces for redundancy as the underlying idea, allowing the equalizer to shock load the anchor if one piece blows?
Also note that if either of the clove hitched pieces in the 3-piece anchor fails, you will also get a TOTAL anchor failure. It goes like this:
Imagine the piece on the far right fails. The remaining cordalette, only attached to th rock in one place, begins to unthread. The loose carabiner with attached pro subsequently threads through the "power point" carabiner on the right, then the un-cloved center carabiner, and finally the last "power point" carabiner. Now that both "power point" carabiners have fully detached from the anchor, the remaining two (presumably bomber) pieces are left in the rock, holding nothing, while all climbers haplessly plummet to the earth, still attached to the now-worthless climbing rope.
Try it. Please don't make me assemble this thing and upload pics/video of the sequence. I suppose I can if it's too confusing.
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dutyje
Jun 6, 2006, 11:09 AM
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All of us (me) who predicted complete breakdown were not considering the green rope in this diagram. Have you taken the remaining climbing rope and cloved it into the three anchor points as a backup? It looks like, in this scenario, you would sacrifice equalization in the event of failure in any anchor point. Shock load would likely not be an issue because of the dynamic climbing rope. However, if the goal is total equalization because the placements not ideal, it seems to be lost once an anchor point fails. The entire load is placed on one of the remaining pieces.
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charlesjmm
Jun 6, 2006, 3:00 PM
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Guys, my basic intention was to suggest a means of incorporating worthy equalization to Sittingduck´s design. As presented, equalization becomes the least of its virtues.
I apologize for assuming the underlying premises of this discussion were understood. Here is a complete version of Sittingduck´s idea (picture 1), i.e., using a sliding x as the primary anchor system and using the climbing rope as a backup system. This means that whenever a placement fails, the sliding x concludes its job and the rope takes over; albeit offering no equalization. As you can appreciate (pictures 2 & 3), failure of any placement is contained adequately by the climbing rope. I used a 7mm, 9 kn accessory cord in an equalized double loop setup, which I believe is more than adequate for a worst case scenario.
http://i49.photobucket.com/...jmm/WRopeBckClar.jpg
I confess not being a huge fan of using the climbing rope for anchor building, although it has gotten me out trouble in several occasions. Using it as a secondary system seems a viable solution as long as it is set up properly, i.e., avoiding potential load multiplication and excessive extension in case the primary system fails. A series of clove hitches with the rope is a time tested solution.
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pipsqueekspire
Jun 6, 2006, 3:49 PM
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OK OK ..... so you really want to change things up. Have fun playing with knots. But before you make any suggestions about SOLVING the anchor "problem" what proof do you have that it works?
The IDEAL anchor may NOT be able to hold every FF2 fall but since it is simple no one screws it up. TWO screw ups per year in a complex anchor leading to death is MORE FATAL than ONE total failure per year in a simple but weaker anchor. Prove to me that your system leads to fewer deaths and then it can be endorsed.
One catch- your "proof" is not allowed to come from a drop tower, only from years of use where anchor failures are at a 0.00000001% level like they are today with a cordolette or current systems. (We talking less than 1 per million uses.)
Will someone please get these people into a stats class?!?!
ARRRRGH
-pip
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bill413
Jun 6, 2006, 4:09 PM
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Charlesjmm - this solution looks fine to me - you have load distribution (I think that is a better, more applicable term than equalization), you have redundancy.
But, it seems that it is only practical for swinging leads. If the leader were to lead for the next pitch, it seems to me that anchoring the second becomes fairly time consuming. Thoughts?
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dominic7
Jun 6, 2006, 4:29 PM
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In reply to: OK OK ..... so you really want to change things up. Have fun playing with knots. But before you make any suggestions about SOLVING the anchor "problem" what proof do you have that it works? The IDEAL anchor may NOT be able to hold every FF2 fall but since it is simple no one screws it up. TWO screw ups per year in a complex anchor leading to death is MORE FATAL than ONE total failure per year in a simple but weaker anchor. Prove to me that your system leads to fewer deaths and then it can be endorsed. One catch- your "proof" is not allowed to come from a drop tower, only from years of use where anchor failures are at a 0.00000001% level like they are today with a cordolette or current systems. (We talking less than 1 per million uses.) Will someone please get these people into a stats class?!?! ARRRRGH -pip
Weren't you spouting this luddite nonsense over on the other thread and everyone told you to STFU?
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glowering
Jun 6, 2006, 5:48 PM
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More good ideas. Thanks for posting.
However, I don't like using the rope in the anchor (but you should know how to do it if needed) because I like to be able to lead in blocks and I like a self-rescue belay escape to be very simple (and leave the anchor intact).
Charles, I think the 3 point sliding X/W is theoreticaly 33/33/33 if there's no knots in it.
What I (YMMV) have been doing is picking my two best bomber pieces and connecting them with a limited knot sliding X with a little extra slack in the strand of the sling with the X in it at the powerpoint. i.e.
http://img172.imageshack.us/img172/9756/x8cr.jpg
Notes: picture shows cord, but I use nylon webbing slings, don't tie the strand any looser than in the photo or there is a danger of the master biner hitting the biner of a piece of pro that failed.
Then I have the best possible equalization for my two best pieces, and redundancy with a single 48" sling. That probably all you really need. But sometimes I'll put in a 3rd piece with a sling that's slightly loose to the powerpoint biner as a backup. Or if needed 2 more pieces with another limited knot sliding X (or tied like a cordelette) that's a little loose at the powerpoint biner.
I leave the limited knot sliding Xs pretied (offset so 1 arm is about 8" longer than the other) and they are very quick and simple to setup.
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sittingduck
Jun 6, 2006, 5:48 PM
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Dutyje, yeah, it is terrible if the pro is not ideal. I might consider a screamer between the harness and power point in such a case, backed up by the climbing rope. How would you set up a trad anchor with less than ideal pro?
CharlesJMM, glad the design seems reasonably OK to you. I like that the sliding x you demonstrate is easier to adjust lengthwise than the cordalette and that it distributes force better.
Bill413, agree with you, not swinging lead takes time. How about if you wait to rig the climbing rope until AFTER the second reaches the belay? You could just make fig 8 loops and hook in. You do not need equalization until someone climbs above the anchor. So when the second comes up you rig the anchor with this design. Then you only need to do it once each pitch.
If all the rope is stretched when the leader are establishing the anchor she can secure herself at the anchor and have the second releasing the climbing rope from the last anchor (both climbers must be securely attached at all time, goes without saying). This should give her as much rope for this anchor as the amount used for the last one.
Since it seems difficult to understand the design, I got this drawing to illustrate. Rip it apart!
http://www.home.no/sittingduck/tegning.gif
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