Bungee at Long Myndd

Hi Pete,

What club do you normally fly at, because the Mynd doesn't have an
abrasive tarmac runway, or for that matter much mud except in the Winter;
just nice smooth short grass well lubricated with sheep dropping. Also to
the best of my knowledge they have always used steel cable, rather than
Dyneema.

I'm glad that someone else has found that Dyneema cable doesn't last
very long in adverse conditions, despite the claims of some of its
supporters. Not long enough to justify its five-fold price tag over steel
anyway, although we found it did last a bit longer.

Didn't you know? The Yanks think that winch launching is only possible
with very fancy computer and tension controlled winches! I presume that
you Skylaunch has the normal throttle presets, so there is not that much
reason to watch the bow in the cable, although as a winch driver I still
do, because I used to drive purely manually controlled Tost winches, when
that and too fast and too slow signals from the glider where about all you
had to go on!

Derek Copeland

At 13:30 03 August 2009, Peter Higgs wrote:
Hi All, I have flown from the Long Myndd, which at 1600ft asl is the
highest gliding club in UK, situated on a 4 mile long N/S ridge.
So as long as there is more than a 15 knot Westerly wind it does not
really matter how high you get on the winch... you WILL GO UP !
They are the only club still able to use Bungee Launching, to catapult a
glider the 50 or so yards from the ridge top, into the rising ridge
lift.

As for the recent Winch Launching debate, we did find that the woven
Dynema cable used on a SkyLaunch winch did break quite often. This was
thought to be because it was used in muddy conditions, or on an abrasive
tarmac runway. It was replaced by some sort of normal 3 strand plastic
rope (8 and 10 mm.) which was easier to splice, and gave better results.

These nylon ropes do stretch a bit first on 'All Out' and can give a
very quick initial acceleration, only limited by the weak link I guess.

A good winch driver is the best 'constant tension' device, he can
judge
the tension from the cab, by looking at the bow in the cable. If its
too
much he winds it in a bit faster, and if it is as tight as a bow string,
he just backs off the power a little.

Pete