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trenchdigger
May 11, 2007, 4:15 PM
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I'm curious what you all think about this one.
My problem with the current design of the equalette is the lack of a single master point that is redundant. To achieve an attachment to a redundant master point, you must use two carabiners on the two strands of the equalette. I frequently belay a second in autoblock mode when climbing multi-pitch, and this adds some difficulty to the system. Also, clipping additional carabiners into the weighted loops of the equalette can be somewhat difficult.
Attached is my idea for a possible solution to this problem.
The advantages of this idea are that the master point is simplified and singular, yet maintains redundancy and the same degree (if not better) equalization as the equalette. The system also eliminates the knotted arm of the equalette by incorporating that junction into the other knots in the system.
The disadvantages are that it is more difficult to untie. I have used a modified version of a double fisherman's knot to tie this version of the equalette. A figure eight or overhand could possibly be used, but I worry about the eight capsizing off the end should one arm fail and the knot is loaded with a carabiner directly on it. I'm not sure the simle overhand would afford enough security in the standard configuration. If the "best" knot for this system can be sussed out, I believe this could be even better than the equalette.
Comments? Criticism? Do I have a few screws loose or is this a decent idea?
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New_Equalette.jpg
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rocknice2
May 11, 2007, 4:28 PM
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This will not work. The DF's will slip towards the master point.
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trenchdigger
May 11, 2007, 4:34 PM
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You're right, they will if you just tie a double fishermans in two strands with the third strand free sliding through the knot. You'd have to do sort of a modified version of the knot - there are a few ways to tie the knot to solve the problem that I've come up with. None are knots I've seen before, but are basically derivations of the double fishermans.
Or there's the option for some other knot that might be better. Any ideas?.
At this point I'm not sure what the best knot is. The point is that the system seems to be an improvement on the equalette for the reasons listed above. Other than your objection listed above, do you see any issues with this system? Think it's better? Or worse?
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drector
May 11, 2007, 4:57 PM
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Figure-8 follow through?
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trenchdigger
May 11, 2007, 5:01 PM
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Well, the drawback to the figure 8 (likewise in the equalette) is that if one arm of the equalette cuts, you have the knot loaded across two strands coming out of the same end of the knot. Eights tend to capsize and roll in this load configuration (hence the reason you use a European Death Knot - the overhand - instead of an eight when tieing ends of a rope together to rap). So maybe a simple overhand would be better? My concern is that the overhand wouldn't be secure enough in the standard load configuration of this system. But maybe it would if you added a backup double overhand on the tag end?
(This post was edited by trenchdigger on May 11, 2007, 5:04 PM)
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majid_sabet
May 11, 2007, 5:22 PM
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If you present this to few expert riggers, I am sure they will all agree that you need some major help.
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trenchdigger
May 11, 2007, 5:24 PM
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majid_sabet wrote: If you present this to few expert riggers, I am sure they will all agree that you need some major help.
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greenketch
May 11, 2007, 6:05 PM
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I'd be willing to play with the idea a bit. My initial thoughts are that this looks like a fiddly time consumer.
If one can get it together in advance it works kinda. But in the more realistic world of a trad anchor with unequal legs all the knots and playing looks from a glance to be slower than I would choose.
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trenchdigger
May 11, 2007, 6:10 PM
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greenketch wrote: I'd be willing to play with the idea a bit. My initial thoughts are that this looks like a fiddly time consumer. If one can get it together in advance it works kinda. But in the more realistic world of a trad anchor with unequal legs all the knots and playing looks from a glance to be slower than I would choose.
No more fiddly or time consuming than an equalette IF you don't have to adjust the location of the knots (in almost all cases, you shouldn't). As with the standard equalette, there are ways to shorten an arm as necessary to prevent the need for adjusting the knots.
This thing is definitely meant to be tied and left tied unless you need the cord to bail off of or something. I treat the equalette the same way when I use it (which isn't very often). I still prefer the standard tied cordelette for most anchors.
(This post was edited by trenchdigger on May 11, 2007, 6:11 PM)
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billl7
May 11, 2007, 6:47 PM
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trenchdigger wrote: Well, the drawback to the figure 8 (likewise in the equalette) is that if one arm of the equalette cuts, you have the knot loaded across two strands coming out of the same end of the knot.
Majid, you are being a dick.
Edit: The overhand knot I mentioned above when one arm goes to one piece is important (and is shown in the Long/Gaines anchor book). If it is not there then cut the loop of that arm in one place and a rolling knot won't be stopped (unless it resets).
(This post was edited by billl7 on May 11, 2007, 6:53 PM)
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binrat
May 11, 2007, 7:02 PM
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Have you tried a overhand knot on each side and an double overhand knot on the standing ends of the rope?
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trenchdigger
May 11, 2007, 7:03 PM
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Thanks for the good info, Bill.
My "improvement" really does nothing more than adding a third strand to the "master point" of the equalette. In doing this, I feel it makes clipping into the equalette easier by eliminating the need to clip each of the standard equalette strands individually, and by making the master point more accessible when the equalette is under load.
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majid_sabet
May 11, 2007, 7:07 PM
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[URL=http://imageshack.us]
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trenchdigger
May 11, 2007, 7:11 PM
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binrat wrote: Have you tried a overhand knot on each side and an double overhand knot on the standing ends of the rope?
Yes. It seems pretty good.
I've also tried an overhand in the "loop" of the arm, then pass the standing end through that overhand, then tie a double overhand in the standing end around the "loop" of the arm. It ends up much like a double fishermans, dresses nicely, and seems like it would be very strong (though I haven't done any testing yet). I may be able to access a load cell to test some of these ideas in the next few weeks. If so, I'll post the results.
Attached is another diagram that may better show the idea, in case my multiple colors of lines were confusing. The blue ellipses are the knots which fix all three strands at that point.
(This post was edited by trenchdigger on May 11, 2007, 7:15 PM)
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New_Equalette2.gif
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majid_sabet
May 11, 2007, 7:17 PM
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I like your last image better.
(This post was edited by majid_sabet on May 11, 2007, 7:19 PM)
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billl7
May 11, 2007, 7:20 PM
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To be clear, I was not discounting your modification.
A lot of folks will like the idea of "explicitly" loading two strands instead of loading each strand via isolated and hopefully same-sized biners. And before you mentioned it, I hadn't considered accesibility of the master point under load.
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trenchdigger
May 11, 2007, 7:20 PM
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majid_sabet wrote: I like it better
It's exactly the same thing, just without the text and leading lines. So tell me why a "master rigger" like yourself wouldn't approve.
Edit: (to accomodate Majid's edit)
majid_sabet wrote: I like your last image better.
(This post was edited by trenchdigger on May 11, 2007, 7:28 PM)
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binrat
May 11, 2007, 7:22 PM
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If you don't have a simple little twist in one of the ropes where the biners are clipped and have an anchor failure, the biners may simply slide over the knot. This would create a system failure. If you twisted 1 of the ropes and clip both strands this will prevent it.
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trenchdigger
May 11, 2007, 7:24 PM
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billl7 wrote: To be clear, I was not discounting your modification. A lot of folks will like the idea of "explicitly" loading two strands instead of loading each strand via isolated and hopefully same-sized biners. And before you mentioned it, I hadn't considered accesibility of the master point under load.
Thanks, yes I understand.
I've tried the equalette and I like the way it works. I just hate working with the master point in any situation other than a toprope with 2 opposte/opposed carabiners.
But when I'm at a semi-hanging belay and I want to bring up a second on an autoblock device, it presents a whole new problem. Then my second arrives at the belay and has trouble clipping into the master point. It just has too much cluster f*** built in for my liking. I think this may solve the problem. I just wanted to see if anyone could poke any holes in it.
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majid_sabet
May 11, 2007, 7:25 PM
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trenchdigger wrote: majid_sabet wrote: I like it better It's exactly the same thing, just without the text and leading lines. So tell me why a "master rigger" like yourself wouldn't approve.
I do not like your middle point as I marked in my pervious image cause during shock load, your center point will hit the hardest due to least stretch and the other two points are only getting a fraction of the load therefore your equalized anchor is not functioning as equalized .
built it simple and do not add stuff you do not need
(This post was edited by majid_sabet on May 11, 2007, 7:26 PM)
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billl7
May 11, 2007, 7:35 PM
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Majid,
Assuming by shock load you mean the initial impact from the fall, trenchdigger's modification has two strands taking the load just as would the unmodified equalette. So the stiffness and equalization is the same. Now, if the 3rd strand is much shorter than the other two then there could be some unecessary loading of that strand, the limiter knots, as well as the two arms of the rig. So make all 3 strands the same length (might already be the plan).
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trenchdigger
May 11, 2007, 7:38 PM
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billl7 wrote: Majid, Assuming by shock load you mean the initial impact from the fall, trenchdigger's modification has two strands taking the load just as would the unmodified equalette. So the stiffness and equalization is the same. Now, if the 3rd strand is much shorter than the other two then there could be some unecessary loading of that strand, the limiter knots, as well as the two arms of the rig. So make all 3 strands the same length (might already be the plan).
The only reason I made one strand slightly shorter was to make it simple to clip 2 of the three. A slight difference in length shouldn't make a difference. In fact, it might make the system slightly stronger because it will prevent the knot from being loaded directly onto the carabiner. That's another thing I'd like to test in a load cell.
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majid_sabet
May 11, 2007, 7:47 PM
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billl7 wrote: Majid, Assuming by shock load you mean the initial impact from the fall, trenchdigger's modification has two strands taking the load just as would the unmodified equalette. So the stiffness and equalization is the same. Now, if the 3rd strand is much shorter than the other two then there could be some unecessary loading of that strand, the limiter knots, as well as the two arms of the rig. So make all 3 strands the same length (might already be the plan).
Bill
A foot of cord stretch differently than 18 inches of same cord therefore we do not need to go thru those arguments. The whole purpose of building any type of equalized anchor is to make sure that we are safe in event of a shock load. That is the whole goal and nothing else therefore, that will leave us with few questions such as;
What type of anchor are we building here (simple, complex).
What is it going to used for?
In event of sh8t hit the fan, what is the worse possibility?
Which one of these anchors point is going to die on us first?
Are we safe in event of 1-2 point fail?
Now we can go out there and build all kind of CF anchor and confuse the fu8k out of ourselves thinking it is bomb proof but then we could find out the hard way or we could just built do the job in simplest way.
Simple = safe = easy to inspect= least fuc8up
Complex = may be safer= harder to inspect= more to miss = more fuc8up
(This post was edited by majid_sabet on May 11, 2007, 11:37 PM)
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helios
May 11, 2007, 7:48 PM
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Would it be better to clip into the strand going from anchor to anchor (what you have drawn as the top strand) and have one of the strands near the end be the third, backup, loop?
I used a quad for multipitch sport at Potrero this year, and it was easy to use and felt super secure clipping into 2 of the four strands for a power point.
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trenchdigger
May 11, 2007, 7:52 PM
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helios wrote: Would it be better to clip into the strand going from anchor to anchor (what you have drawn as the top strand) and have one of the strands near the end be the third, backup, loop? I used a quad for multipitch sport at Potrero this year, and it was easy to use and felt super secure clipping into 2 of the four strands for a power point.
Ideally, it shouldn't matter which 2 of the three strands you clip, so long as the knot properly fixes the line.
I agree with your sentiment on the Quad. It's just bulky overkill. This takes only about 60% of the cord required for a Quad. This is my attempt at finding something simpler.
Thanks for your feedback.
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