OK so Iam I seeing that right, It looks more like an american death triangle.

OK so Iam I seeing that right, It looks more like an american death triangle.

pps: Aric, I've been pinging you, but ... Sounds of Silence ?

They all remind me of something to do with female anatomy and birth control.

That looks really dangerous with spectra slings. Tied spectra slings tend to slice through at low forces especially if the knots can slide and cinch adding heat to the equation. This has been shown repeatedly in girth hitched slings.
To be honest ...

http://www.alpinist.com/...-broken-sling-report
My quick search turned up the Mammut study cited in the article above. I admit that it's not as bad as I originally thought but they still caution against tying knots in dyneema slings. ...
Low stretch materials and tight bends just don't go well together. In tight bends the strands have different path lengths and the longest paths bear most of the load. ...

but I still don't see any real advantage over existing systems. I think that for most cases the redundancy is overkill. Maybe if you're in serious rockfall terrain.

orange and white sling twice instead of adding the American triangle.

If you want redundancy for that sling breaking why back it up with an inferior system?

I prefer something like this ...

The experiment that I am most interested to see is something that explores rope dynamics. What is the Hook's law regime? Is the damping critical? What are the recovery dynamics? How does all of that go into shock loading and zippering?

Looks like I only pulled it to 5kn, but with only one loop of the powerpoint and one leg leg connected.

And remember, the knots joining the runners are essentially Eskimo bowlines and rather strong ...

... with only 1 of the 2 loops clipped and pulled to 1129 lb-f (~5kN). There was some creep in the knots (as shown by the blue threads no longer being tight up against the knots), but far less than I expected.

ELET ::= Extension-Limiting Equalization Triangle

The ELET is a general schema. Its essence is the containment
of the powerponit connector, and the limited extension if one side
fails. How it gets implemented will vary on circumstances per user.
...
There are also clever ways of implementing the entire thing in cord.

[re use of HMPE slings] ... but I still don't see any real advantage over existing systems.

Warnings: Me [CraigC.]: my academic and professional careers have involved making, analyzing, and reporting sensitive scientific and engineering measurements, and I'm acquainted with the stick/slip and slide rate issues when measuring friction. I didn't do drop tests or attempt any kind of abrupt loading[--]I didn't attempt to simulate fall forces. What I did was make a number of 2-placement anchors in a consistent geometry using a variety of materials, hang a heavy weight at the master point, and use an accurate spring scale to measure the force required to pull the master point sideways through its equilibrium position (referring to this force as indicative of friction , in this discussion). I didn't make enough measurements to do statistical studies (no standard deviation, no chi squared tests, none of that), but if I had to guess I'd say the standard error would be maybe 20%. No observations were earthshaking or inexplicable. If these warnings make you think such measurements would be useless, not germane to this thread, or misleading, now would be a good time to stop reading.

Otherwise, here's what I observed.
I set up 3 different anchor designs: the Sliding-X , the 2-anchor Equalette , and the "[ELET ]".

[..]

* Normalizing to the sliding friction of the Sliding-X , I measured the sliding friction of the Equalette to be about half that. The sliding friction of the ELET measured about half that of the Equalette (1/4 that of the Sliding-X), which is what you'd expect just by looking at their designs. This was true will all the soft materials I tested. These observations refer to an equalette without limiter knots. Tying limiter knots in the Equalette decreases the measured sliding friction. I interpret this to reflect the difficulty of tying limiter knots that create perfectly equal length strands between them (in their final position as they support the carabiners, necessary for perfect force balance at the master point) and perhaps to irregular orientation possibilities of the two identical lockers. This is another illustration of the dictum already brought out, that perfect equalization requires cord/webbing slip around the anchoring carabiner and that limiter knots prevent this. I didn't test it, but likely a Sliding-X with limiter knots would have the same issue. In other words, limiter knots tend to make the Equalette perform more like an ELET, which is good in terms of reducing sliding friction but not in terms of balancing the loads on the two strands.
* I could not resolve a difference in the sliding friction of 11/16 (18 mm) climb spec webbing and 7 mm accessory cord, in any of the anchor configurations.
* There appeared to be a reduction in sliding friction going from 7 mm cord, to 6 mm cord, to 5.5 mm Tech Cord, but the effect, if there, was small in all 3 configurations.
* I measured a significant decrease in sliding friction using Spectra/Dyneema webbing, compared to nylon. The difference was almost a factor of 2, meaning that a Sliding-X with HMPE (Spectra/Dyneema) webbing would perform almost the same as an Equalette made with 11/16 nylon webbing or 7 mm cord. I question whether limiter knots or hitches tied in HMPE material would hold satisfactorily.
* I could not resolve a difference in the sliding friction in any anchor design between ordinary 1/2" Spectra/Dyneema webbing and a Mammut 8 mm Dyneema dental floss sling.
* I did notice an improvement in sliding friction when using a "wide mouth anodized pear biner," compared to non-anodized HMS/pear lockers (which had apparently larger rope bearing radii), but I tested this only with the Sliding-X and ELET because I didn't have two matching anodized HMS/pear biners with their anodizing intact. While the effect was noticeable, it was near the resolution limit of my testing.
* Presumably, lower sliding friction is better, because that will allow better balancing of forces during the instant of peak fall force, thus better achieving the design objectives of the anchor, but applying these observations to or making conclusions about any anchor design when impacted by real fall forces is outside the scope of my inquiry this weekend.