On Nov 29, 4:23 am, Del C
wrote:
UHMWPE cable, such as Spectra, Plasma or Dyneema (trade
names) is pretty amazing stuff. It looks like washing
line, but is stronger than steel whilst being 10 times
lighter. Unfortunately it is also about five times
more expensive than the equivalent steel cable and
requires modifications to the winch. For the lengths
of winch run we use, normally about 4200ft, it wasn't
found to give that much improvement in height, less
than 100ft, and was deemed by our Committee not to
be cost effective. It would certainly come into its
own on 5000 feet or longer runs, when steel cable starts
to become significantly heavy.

From a winch driver's point of view, I've always thought that the most
appealing aspect of UHMWPE is it's pleasant handling - it's light,
doesn't "ping back" if released under tension (which can be disastrous
with steel), and doesn't cut your hands, and you can use much smaller,
cheaper and more fuel-efficient retrieve vehicles. On the other hand,
from the reports I've heard, the winch needs to be set up *perfectly*
or the expensive cable can be ruined in one launch. It's also a
_little_ trickier to repair when it does break, though nothing that
proper training can't handle.

The main issues with UHMWPE seem to be two-fold: the initial cost of
modifying a winch to use the cable, and the lifetime vs. cost ratio.
Right now, UHMWPE doesn't seem to last as many times longer than
steel, as as many times it costs to buy versus steel.


Dan