Halyard Failure

[Brion Toss]

Hi,
That is indeed scary. If the halyard is indeed Vizzion, it is a composite core, with non-structural polyolefin as filler for Vectran, which takes all the load. This halyard makes sense when you (a) want to save money, (b) still want HM performance, and (c) want a fatter, easier-to-handle line. But if you, say, replaced an all-HM core with this blend, and didn't change the diameter (because of "a", above), you'd have a halyard that was at best only half as strong as it used to be. And if, as so often happens on go-fasts, the original, all-HM core rope wasn't exactly oversized, you'll be putting a horrendous load on a relatively weak rope.
This is all speculation, of course, but you could confirm at least some of this by, wait for it, running the numbers on halyard load, and comparing the result with the strength of the rope you have.
It is not likely that the clutch is to blame, else you would have seen more chafe on the cover. But one other variable is how much tension is placed on the halyard by the crew; overtensioning would make things even worse.
So I don't think that a replacement schedule, by itself, would necessarily help, if the problem is that the rope is not up to the loads. Please get back to us about this.
Fair leads,
Brion Toss