[MHml] Synthetic rigging

[Diane Selkirk]

Bill Gibbs wrote:
>
> I’m told if the load is kept a small fraction of breaking strength 
> (<20%?) that creep s/not be a problem.
>
> The initial stretch in a synthetic line is due to mechanical stretch 
> in the weave. Pre-stretching reduces this. Once loaded and retightened 
> a few times, the line becomes much more stable. Then you still are 
> left with elastic stretch, which is 2-3 times more than steel, and 
> proportional to the load over breaking strength. Creep sets in from 
> long time at high load in spectra.
>
> Bill
>
> Afterburner
>
We use (hanging head in shame/embarassment) 1/4" Dacron double braid on our 40' Woods Meander cat.  Probably at least 24' to each tiller.  It's actually slightly sloppy (i.e. very little pre-load) so that the friction in the system doesn't make the wheel hard to turn. I like it.  There's so little feel in big cruising cat steering anyway that a bit of slop in the system isn't noticed as a problem.

If you use Kevlar you should use the special flat sheaves recommended for Kevlar

I doubt you will pretension spectra or load it enough to matter.

I'll replace mine with spectra when I get around to it.

Evan Gatehouse