Halyard Failure

[allene]

Originally Posted by Brion Toss

Even a covered 9mm rope with Spectra core will be about three times stronger than the same diameter Vizzion. I don't see that as "comparing reasonably well." In addition, the polyolefin filler fibers in the Vizzion won't be able to do their job (keeping the Vectran fibers from slicing each other) very well while being crushed by a clutch. I'm sticking with the idea that the rope is not up to the loads.
Fair leads,
Brion Toss

3/8 Vizzion 4,300 pounds. 9mm Amsteel Blue 19,600 pounds. Not close.

That said I have been thinking about the clutch and how it holds. It puts pressure on the rope over some length or area. The friction over that length has to hold the load. The more square inches involved, the less force in pounds per square inch has to be put on the rope. Different clutches work in different ways but it might be worth looking at the clutch to see if the load is being spread correctly. If there is some part not doing its job such that the contact area is reduced that would greatly increase the crushing force on the line. The extreme example would be a knife which would have very low contact area and cut right through the line.

The other point is that straight spectra is not very good in a clutch because it has slightly less than half the friction for the same force from the clutch. It is recommended that it have a cover over the part in the clutch.