Author Topic: Dorkalette  (Read 4590 times)

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Offline Garbonzo

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Dorkalette
« on: July 22, 2009, 07:00:37 pm »
I'm probably a couple years behind the times, but I've been scratching my head over the Equalette, and frankly don't like it.  So I did some thinking, and came up with an alternate idea I like better that I think is slightly less dorky.  I figure using SRENE is a valid point for looking at any anchor.
 
BTW, SRENE is an oxymoron.  You can't really have equalization without any extension.  SRELE ("surreal", Strong, Redundant, Equalized, Little Extension) better describes what we really want/need in a climbing anchor.  Redundancy is not just multiple pieces, but also that no single point failure exists (i.e. you should be able to cut any one point in the system, and not have a complete anchor failure, a single sling in a sliding X is not redundant for example).
 
Cordalette:  Cordalettes don't equalize except for one direction (straight down if that's how they are tied), but are redundant, and usually have little extension.  Also most cordalettes are too short for 4 pieces of gear unless they are very closely spaced, or you do some additional tricks (i.e. 2 pieces of gear into one leg).  I particularly hate what a cordalette does for a fixed line on a wall if the last move was a traversing piece (i.e. the angle of pull changes 90 degrees when the cleaner gets to the anchor, leaving the cordellete looking FUBAR'ed either while jugging or once at the anchor).  I've used the cordalette on walls, but hated the lack of equalization for anything but vertical loads.


 
Equallete:  Largo's contribution is a decent one, but I'm just not a fan.  It is redundant, equalized, and has little extension, which is great.  It works with 3 or 4 piece anchors, is sort of equalized (dynamic sliding equalization between two statically equalized V's), also for 3 piece anchors the odd man out gets 50% of the load no matter what, with the remaining 2 statically equalized for the remaining 50%.  However in the case of purely horizonal pull in my jugging scenario the sliding region quickly maxes out and again you have only one piece taking the load.  Also it calls for two lockers to create the powerpoint, and has two big fat knots that are fixed in place.  On paper the Equalette sounds pretty good, but it just doesn't float my boat.  A few variations exist that get rid of the 2 locking biner requirement, but those result in bigger knots, generally it just isn't as flexible a system as I want and still doesn't solve the horizontal fixed line scenario.


 
Triple/Quad sliding X:  A single sling/cordalette loop can be looped through 2, 3, 4, or even more pieces to get a equalized anchor, but does not have redundancy, has lots of extension, and Largo argued that it didn't really equalize well due to friction at the master point.  More horrifying is that it is hard to inspect if the looping was done right, in which case the results can be quite bad if one piece pops.  Lastly, clipping biners into a loaded power point is really obnoxious for the 3 and 4 piece cases.  On the plus side it does actually do some equalization in the horizontal load case.


 
Alpine Equalizer:  Trango's wiz-bang toy is NOT redundant, has a lot of extension, but is equalized (and spiffy looking).  At $40 a shot, it's also a lot more expensive and specialized than folks like me like.  Mal from Trango says (right in the instructions http://trango.com/pdfs/EqualizerWebInstructions.pdf) you can either A) tie an overhand knot in the center strand to limit extension or B) tie three cloves in the protection biners.  Option A confuses the hell out of me because the main loop is a single strand, and is not sewn to the little loop with the metal rings (they share a rash guard, but that's it), so in the case of either of the two outer pieces popping, there is no improvement in redundancy or extension, WTF?  Option B is relatively brilliant.  You create 3 V's of webbing that cradle your biner.  Voila, redundancy, limited extension, but there is no longer full equalization.  Equalization is down to 50/50 between 2 pieces, with the third sitting there doing nothing (unless one of the two loaded pieces pops).  I like this a lot, as it's as close to SRENE as I think you can get without lots of complicated limiter knots.  However it is limited to 3 pieces, and costs $40 a pop.


 
Well Shit.  Lots of options, none perfect, and only the dorky Equallete and cloved alpine equalizer meeting the SRENE/SRELE (and again, only 50/50 load sharing guaranteed), and even the equalette fails the SRENE/SRELE criteria for horizontal loads (depends on exact gear location of course).  So either $40 a shot, nerdy equalette, or find something new.
 
So I played with a bunch of crap (making lots of needlessly complex setups) and came up with a simple variation that comes close without being complex, or requiring anything special.  It's just combining Mal's clove hitch fix to the Tripled sliding X to come up with something with all the benefits, without being a specialized piece of gear or costing $40 a pop.
 
3 Piece Anchor:
1.    Start like with a cordalette, looping through all three biners.
2.    Pull the strands down and overlap the loops to create your master point and wiggle to get the strands even them out (clip a biner in to keep it open).
3.    Clove-hitch the loops to the 3 protection biners, and tug on the master point to cinch them up.
 
SRENE'ish:  Redundant, check.  Equalized, sort of (statically equalized for downward pull, but off center pull loads 2 pieces 50% each), Little Extension, check.  Horizontal fixed line case, check (a little ugly, but maintains 50/50 equalization).  Essentially this is the same underlying physics as the alpine equalizer done with clove hitches, but using $15 of cord instead of a $40 specialized piece of gear, and most folks are already have a chunk of cord for this exact purpose.
 
Note:  Full redundancy requires the cloves hitches don't slip, so probably best to use 7mm nylon, or nylon webbing for your material.  A standard 20' cordalette works for this thing, but is pretty long, a ~16-18' one would probably be better if you like the length you get from a normal cordalette.
 
4 piece anchor:
1.    Put a half twist in the middle of the cordalette loop to create a big "8", clipping one loop through the leftmost two pieces, and the second loop through the rightmost two pieces.
2.    Pull the strands down similar to a cordalette and clip a biner into the loops to create a master point.
3.    Clove-hitch the loops to the 4 protection biners and tug on the master point biner to cinch things down.


 
The half twist in the middle changes how the thing extends if a piece pops, but it makes little difference except in the case of the it being pulled far from the nominal position, like a horizontal fixed line in the case that the upper right piece popped.
 
Why I like this approach:
1.    Fairly easy to add biners to the master point even when loaded.
2.    No piece takes more than 50% of the load, and you have static equalization in the vertical case.
3.    Clove hitches are easy to untie, and there are no extra fixed knots like with the Equallete.
4.    There is still at worst 50/50 load sharing for a 90 degree change in load angle.
5.    No specialized gear beyond the cordalette you likely already have, and even a 6' or 8' sling will work (if a clove won't slip, so probably a bad idea with those mammut slings).

Stupid?  Comments?
« Last Edit: August 24, 2009, 12:03:18 pm by Garbonzo »

Offline *Mucci*

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Re: Dorkalette
« Reply #1 on: July 22, 2009, 07:46:29 pm »
Very informative.  Having used every type but the alpine, yours seems easy, and well thought out.  What if you are jugging up and left to the anchor and the 2 middle pieces blow, and the two outer pieces remain, is the force still 50/50 or does the orientation of the powerpoint biners play a role in load distribution?

Offline Garbonzo

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Re: Dorkalette
« Reply #2 on: July 22, 2009, 10:33:57 pm »
If you do the 4 piece like pictured here's what's going on:

Dorkalette:
1.  Let's call the pieces from left to right 1, 2, 3, and 4.
2.  With a twist in the middle (the "8") you get V's between pieces 1&2, 1&3, 2&4, and 3&4 (everyone except 1&4 and 2&3).
3.  Jugging up to the left (last piece of pro to the climber's left) the anchor will be loading the V between 3&4, 50% load each, assuming the angle between them is fairly narrow.
4.  Piece 3 blows due to load.  The jugger gets dropped a few inches as the V between 2&4 gets tensioned, each taking 50% of the load.
5.  Piece 2 blows due to load.  The jugger gets dropped a good couple feet this time, and pieces 2 and 3 get sucked into/through the masterpoint biners.  If they get sucked through successfully eventually pieces will equalize to 50% (i.e. theory version).  More likely there will be a snarl, desperate squeeling from both the leader and the jugger, and only one of the remaining pieces will take any load.

Dorkalette withOUT the twist in the middle:
1.  You get 4 V's again, but now they are between 1&2, 2&3 (absent last time), 3&4, and 1&4 (also absent last time).  The V between 1&4 is wide, and will be stress the gear more if loaded than in the prior scenario.
2.  The V between 3&4 will once again be loaded with equal sharing.
3.  Piece 3 blows, dropping inches onto 1&4.  1&4 had a poor angle between them, so load sharing is more likely 60% each, if not worse.
4.  Piece 1 blows (worst case), dropping the jugger a couple feet.  Squeeling and cluster ensue as now only 2 and 4 are left and have no direct V between them, so pieces 1&3 now have to get sucked through the masterpoint biners for equalization to resume.

By comparison, here's what the Equalette would do:
1.  Only piece 4 would be loaded, taking 100% of the jugging load.
2.  Piece 4 blows (closest I can get to your scenario), dropping the jugger inches onto piece 3, now taking 100% of the load.
3.  Piece 3 blows dropping the jugger a couple feet, loading piece 2 100%.
etc. etc.  It is this scenario that scares the crap out of me.  I want an anchor that never loads any one piece with the full 100% load, or will shock load onto a single piece if one fails.  The equalette looks to do well for most cases except large angles (jugging case mentioned, of if the start of a climb traverses out right as happens on some big wall pitches).

Which is a worse scenario?  I personally prefer to have the jugger held by 2 equalized pieces over just 1, and prefer that any single point failure not shock load onto any remaining pieces with the full 100% of the small shock load.  YMMV.
« Last Edit: July 23, 2009, 02:40:50 pm by Garbonzo »

skully

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Re: Dorkalette
« Reply #3 on: July 22, 2009, 10:46:27 pm »
Truth is, if it's your anchor, it'll be fine.
You'll see to it.
Don't overthink a simple thing. Simplify.

Offline hoipolloi

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Re: Dorkalette
« Reply #4 on: July 22, 2009, 11:08:47 pm »
im with skully.

Especally if you have big fat bomber bolts.  Slings dont break, carabiners dont break.  give it a back up and go.

If its some sketchy Mankor then get a little more fancy and use some thing a bit more techy.



How many anchors have you heard of yanking out completely?  Basically none, right?

Offline *Mucci*

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Re: Dorkalette
« Reply #5 on: July 23, 2009, 12:04:54 am »
Ah "With a twist" is the key, prolly less shock than a normal cordallete if one piece fails.  good stuff!

Sometimes I just use the rope with dog eared figure eight and bights.  Nothin like a fat cord anchor!

skully

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Re: Dorkalette
« Reply #6 on: July 23, 2009, 01:03:35 am »
A lot of times, I just clove  in series....It works, for me.

Offline mungeclimber

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Re: Dorkalette
« Reply #7 on: July 23, 2009, 11:40:59 am »
I dare say this forum has come to full fruition with this kind of contribution. Thx Garbonzo!


i'm really curious about the set up. say you get one sliced bit of cord near the power point, e.g. friction moving back and forth from e.g. jugging movement. what happens in that scenario?  Having a hard time visualizing the redundancy here. I'm probably just not attending to it enough.

Offline Garbonzo

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Re: Dorkalette
« Reply #8 on: July 23, 2009, 02:35:39 pm »
I dare say this forum has come to full fruition with this kind of contribution. Thx Garbonzo!


i'm really curious about the set up. say you get one sliced bit of cord near the power point, e.g. friction moving back and forth from e.g. jugging movement. what happens in that scenario?  Having a hard time visualizing the redundancy here. I'm probably just not attending to it enough.


At the masterpoint there are 3 V's (if it's a 3 piece dorkalette).  The biners in the master point are being cradled in the bottom of the V's.  In the case of a 3 point anchor there are V's between 1&2, 2&3, and 1&3, cut any one and you now load the cloves, and are held by the remaining 2 V's (and still be only loading any one piece at ~50%).  You are doubly redundant against cuts anywhere except the within the clove hitches, to which you are only single redundant (slice any one clove and you are only held by a single V between the remaining two cloves).

The 4 piece anchor is triple redundant against everywhere cuts except in the cloves, where you are only single redundant.  After cutting a single clove only two out of the three remaining cloves can be cut and not drop you, but if you pick the unlucky of the three you can still get dropped:  Cut cloves 2 and 3 you die.  Cut 2 and 4, and the V between 1 and 3 holds.  Cut 2 and 1 and the V between 3 and 4 holds.  Do you call that 1 and 2/3 redundant?  I round down to just singly redundant.

By comparison the Largo Equalette is triple redundant against cuts everywhere except the sliding masterpoint, where it is only singly redundant.  Some variations exist that are at least double redundant against cuts there.

The only severe wear I've seen in an anchor was a TR anchor in Jtree that just kept sawing over a rough spot (it was expected, and pre-emptively backed up with a slightly longer sling).  In my non-professional opinion single redundancy for cuts is probably plenty.

Offline mungeclimber

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Re: Dorkalette
« Reply #9 on: July 23, 2009, 08:24:05 pm »
I gotcha.  perf explanation.


Offline lambone

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Re: Dorkalette
« Reply #10 on: July 25, 2009, 01:36:58 am »
The old bunny ears figure 8 works pretty good and only rquires two biners.

Offline Caz

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Re: Dorkalette
« Reply #11 on: July 25, 2009, 09:24:28 am »
I'm with Lambone...
I do this for fun...

Offline Garbonzo

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Re: Dorkalette
« Reply #12 on: July 25, 2009, 09:33:29 am »
Nothing wrong with the bunny ears, but it isn't really the same usage.  Bunny ears are great for 2 bolt swinging leads.  Once you are dealing with 3 or 4 piece anchors, or want something above and beyond static equalization, it is just a round peg square hole solution.

Offline kristoffer

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Re: Dorkalette
« Reply #13 on: August 23, 2009, 11:00:46 pm »
nice Garbonzo, i like how you have improved on pre existing designs. thats what keeps this sport moving forward. about 6 months to a year ago i created an anchor system i call the octa-anchor, its a 4 legged multi directional system designed for pure natural big wall anchors that can handle 8 main points of contact that can be expanded with the use of smaller sliding x's... its actually pretty sick but totally over kill for anything but stuff that depends on anchors build from tons of sketchy gear. i will post it up on this site some time, but right now i am pretty tight on time and the internet out here damn slow!

p.s. keep the good climbing posts coming guys, other than working on the flight deck my excitement is limited on this floating city, so I am forced to live vicariously through you guys and what you all are posting.

from some where in the pacific -zephyr loggin out
"I am plagued by a mindless nonchalance and petrified zen"