TRANSPOSITION (exploring the concept)

[Dan_Lehman]

@agent_smith post:20

EDIT NOTE
A further remark from Dan Lehman in relation to Mobius Butterfly jamming:

Yes, very tight; and in my quick check in some small super-flexible/soft cord I see jamming writ large --which, of course, stands in stark contrast to your well-specified check in intended material. But I remain skeptical.

Again, I have taken the Mobius Butterfly up to 8.0kN force. Result: No jamming, and super easy to untie. This was with EN892 dynamic rope (Beal Opera 8.5mm). If you think about it, [u]both the Butterfly bend and the regular #1053 Butterfly eye knot are well suited [b]to [i]through[/i] loading[/b].[/u] In fact, when through-loaded, they are resistant to jamming. I think you already know this! And so, why would the 'Mobius Butterfly' be any different?

Wait, in what loading were your test results given for?
–through?! I thought it was of both or one of the S.Parts
vs. the eye around a host?!

(The lineman’s loop has been faulted for jamming when
loaded qua EK, the unloaded end’s collar being able to
then collapse and bind it.)

–dl*

[agent_smith]

From Dan Lehman in relation to load testing of Mobius Butterfly:

Wait, in what loading were your test results given for? --through?! I thought it was of both or one of the S.Parts vs. the eye around a host?!

Refer to attached image below. [ ] Transverse loading up to 8.0kN = No jamming [ ] Axial loading up to 4.0kN = No jamming

NOTES:
The ‘axial’ loading profile replicates the use of a Mobius Butterfly
being used as a dual leg lanyard.
User groups being rope access workers and recreational climbers.
In this configuration, the Mobius Butterfly will never see loads
beyond 4.0kN.

In transverse loading, this replicates how SAR teams would use the knot.
eg Tied around a sturdy tree.
SAR teams will never reach operational loads beyond 8.0kN.
In fact, typical loads are between 2-4 kN.
8kN would be extremely remote.

(The lineman's loop has been faulted for jamming when loaded qua EK, the unloaded end's collar being able to then collapse and bind it.)

Correct, when eye loaded, a regular #1053 Butterfly will jam. The jamming threshold when [i]eye loaded[/i] is around 3-4kN (EN892 dynamic rope). Indoor climbing gym operators often use a Butterfly in their dual clip-in systems - where the Butterfly sustains all of the load. After a period of sustained use by climbers, staff often have trouble untying the Butterfly knots to cycle their belay ropes.

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