Synthetic fibres -- objective performance ratings?

[Brion Toss]

Originally Posted by Bob Pingel

The knot story is in the Feb 2007 issue (page 82 by David Schmidt) . The testing was done at New England Ropes.

They tested 1/2" double braid nylon, 1/2" Sta-Set, and 1/2" Endura Braid with a bowline, a clove hitch backed with halfhitches, a round turn and halfhitches, a figure 8 follow though, a double fisherman's knot, and an eye splice. No details were given on the eye splice, but I assume it was to NE spec.

As expected, knots in the Endura Braid were pretty bad, they only retained about 30-40% of the strength of the rope . The tensile was tested at 19300#, I believe published is 19000#. The eyesplice broke at 20594#.

The eyesplices in the other ropes were about 78% and 88% efficient at the measured breaking strength -- the measured breaking strengths were about 20% higher than published numbers. The knots were about 50-60% efficient.

It would be interesting to see a comparison between Endura Braid and Endura12 of the equivalent size. I'd assume the cover helps some -- by adding friction.

I would have expected the knots and eyesplices in the nylon and dacron to fair a bit better. The knots were only about 25% better than the same ones in Endura Braid. I would have expected the eyesplices to be closer to 100% efficient.

Bob

Hi Bob,
I'm looking forward to seeing the article, especially to see what variables might account for the odd results (like those very low splice numbers). As it happens, two of our apprentices just got the results back from their destruction tests, and nearly all of the splices appear to have approached 100% efficiency, so I know it can be done.
Fair leads,
Brion Toss