Note that while belay loops are very reliable, curiously there are no equally reliable mid-line loops in webbed goods. For example, the daisy chain with sewn loops has a startling history of breaking under low loads, i.e. the force of a carabiner in the sewn loop bursts the stitching.
The same can be tried in ropes: pockets or loops formed by bending two strands at intervals and examining the resulting merit of these pockets. These seem to be the same forces at hand as what this discussion has primarily focused on (loops in the bight).
I can see that this thread topic has drifted off course…
The belay ‘loop’ on a climbing harness can be loaded in any direction (axial, transverse or circumferential).
It makes no difference because it is a circle and it has no hand tied knots that form any join.
On the other hand, a fixed eye knot - eg #1010 simple Bowline - is vulnerable to certain loading profiles.
That’s because it has a joining knot (unlike a harness belay ‘loop’ - which is factory stitched).
For example, a [i]transverse /i loading profile will initiate slippage - and lead to knot failure.
However, a steady (unchanging) axial loading profile does not initiate failure (however, #1010 is vulnerable when load is cyclic or slack-shaking - it initiates failure mechanism).
The nominal loading profile for all fixed eye knots is typically in the axial direction (ie longitudinally aligned with the SPart). #1085 Double F8 (aka 'bunny ears) has 2 eyes which can be separated and loaded in different trajectories (usually not exceeding 60 degrees included angular separation).
The eye of the Mobius Butterfly is remarkable because it can sustain loading in a number of directions and still remain stable.
The eye of the Mobius Butterfly remains perfectly stable when subjected to a transverse (cross) loading profile.
Many other fixed eye knots become unstable in this type of loading profile.
However, the Mobius Butterfly is not so good when subjected to ‘through loading’ (from SPart-to-SPart)…I m still investigating ways to mitigate instability in this loading profile.
Belay Loop, is a sound bulldog strong device;
Who’s stronger, connecting foundation allows it to self adjust (not be held fixed)the loading angle to the served out Belay Loop.
The Belay Loop itself does not deform from the inline geometry (so much) ,
‘rotating’ on it’s base to accommodate the possible working angles of pull, unlike Bends/Hitches that have 1 peak best angle of pull.
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