Small tech cord

[moss]

knudeNoggin, thanks for the detailed interpretation of the tech cord pull test results. I'd looked at it a while ago but had missed WHY a triple overhand knot made such a difference in strength. I use 5mm NE Ropes tech cord tied in a sling and girthed as my ascender attachment for SRT. I'm going to convert from double overhand to triple overhand now.

It makes me think they should weave some technora into the sheath to reduce the problem of the the sheath breaking at the knot.
-moss

 

[knudeNoggin]

[ QUOTE ]
It makes me think they should weave some technora into the sheath to reduce the problem of the the sheath breaking at the knot.

[/ QUOTE ]

This misses the point: firstly, the sheath, being exterior, will
be what gets the most compression on it; but why it breaks is
(IMO) also because the core is SLIPPING WITHIN IT, and so the
load-holding is being done increasingly by the sheath.
I do note that in one of those tests the difference in strength
between the Grapevine & Dbl. Grapevine was pointed out as being
small, AND that the point of rupture in the latter case moved
from the knot to the (presumably relatively small-diameter) PIN.

*kN*