[Joe Henderson]

Dear Brion,

How nice to have an owner with the vision and courage to break out of the wire rope standing rigging alley and allow you to explore other avenues. I am very jealous!

You are quite right. I should have written stretch or elongation instead of creep.

I did find that the nearer to the breaking load we got with the pre stressing the less creep crept into the equation. This is what I expected with constructional stretch but not with deformation of the material.
Maybe what we have been thinking of as creep, in the context of spectra, is just another manifestation of constructional stretch but at a higher percentage of breaking load.
It is a long time ago but it did occur to me that as I loaded the stuff up it seemed to give and hold in steps. Initially quite a lot of give then holding for a while then giving again as the load increased until the strain seemed to plateau as the load got to 75/80%.

All this is purely observational on my part, and I did not have the time to do a proper test and repeat and the dynamometer I was using could have had some error, so it is all open to challenge and query! not only that but the core I had to work with was not of the highest quality. ( I used to dream of getting hold of some Sampson Spectron 12!)

With some sense of frustration and in an attempt to get an idea of what was happening inside the material I left a pair of runners in the loft stressed to 80% of their break load over the christmas holidays and when I snuck back to look at them on new years day they had lost about 5% of the load and one pump on the Tirfor (about 15mm on the runners) set it back up.

In the end I was stressing the material to about 75% of the makers listed breaking load of the Spectra core, serving very tightly with Dacron V.B.cord and coating with polyurethane.

It all got a bit sobering when I thought long and hard about the consequences of a failure while my wife was putting on the serving and anyway Vectran had become available at a reasonable price so we did not have to keep scaring ourselves!

During the rigging program for the halyards on the maxi we came to the conclusion that the spectra jib halyards may have been stretching/ creeping during a beat because we were not stressing the material highly enough.

After a lot of buggering about with smaller and smaller rope which needed larger and larger covers to work in the clutches, we got rid of most of the elongation by using good old cheap, unfashionable, fragile kevlar in the straight runs and inserting spectra portions at the hounds and at the deck turning block and clutch. quite simple to do and it worked, we never broke a halyard in normal use, which probably means they were too big. The kevlar we used was actually some left over from Australia III's Fremantle A.C.campaign which was in the hundred or so assorted reels I bought when the rope makers were clearing their stock room.
I still have a reel of 12mm lurking at the back of the loft for that special job that is always just around the corner!

In regard to using vectran for drop over eyes, I wonder if inserting a short length of spectra at the top end for the eyes would be the way to go. It would mean that you wont have the ease of replacement inherent in your system, which I can see will be important with fibre shrouds, so maybe not.

Did you leave the cover on the Vectran?

Regards, Joe Henderson.