Oh yes, Optic cable was something we did make.

Most of it used a steel strength member but there was also the non-metallic
Kevlar (and GRP) strengthened types. However, manufacturing the cable so
that the kevlar strands were all at the same tension and did not introduce
a twisting moment on take-up, was something of an art.
The cables, however were generally well regarded as far as strength went -
we saw some horrific tensions applied at times under "emergency repair" and
other conditions and had few complaints about failures. Just before I left
we were working on a shotgun resistant jacket. Not very successful at that
time but it was fun testing it!

Our Australian company manufactured a cable designed to be laid over
marshland. The core was a sort of sponge rubber and the cable was designed
to elongate. As the cable stretched, the pitch circle diameter of the optic
fibre path reduced and so extra fibre was available for the elongation.
Quite clever and I think it would withstand about 10% elongation (maybe
more?). Very expensive though and never very popular with the customers.

Richard P




On Wednesday, Feb 11, 2004, at 13:05 US/Pacific,
Richard.Prosser@POWERWARE.COM wrote:

> I don't think the strings would contribute much to pulling-in strength
> as
> by the time they had the slack taken out of them and their elasticity
> taken
> up the cable would have been too extended.

I'm pretty sure some of the fiber cable has kevlar strings added for
pull
strength.  you don't want to be stretching glass fibers!  (kevlar does
not stretch to speak of...)

billw

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