I understand that Supercat
http://www.supacat.com/ have not in fact built
any new winches for some 10 years. The company still trades but is busy
with other products.
See the article by Gordon Peters on the on-line Gliding & Motorgliding
International site,
http://www.glidingmagazine.com/ListF...Dtl.asp?id=345 . His club
is the one where the Clayton winch originated in the late 50s or early 60s,
and the Supercat is a development of it. Remember that the original layout
of the design, still seen in the Supercat, was done to work with piano wire
(single strand) as distinct from stranded wire. The Tost, Van Gelder and
Skylaunch winches would almost certainly fail with piano wire, but this does
not matter because nobody uses it any more.
Big V-8 engines from the USA, petrol (gasoline) converted to run on Propane,
are now the engine of choice for winches in the U.K. I understand that the
engines used in the Skylaunch are the marine versions. They are of course
fitted with the usual automotive automatic transmission, I don't know if
these are modified for winching.
These engines have been in use in the U.K. for many years, for instance in
Tost winches of which there are a number here. The special features of the
Skylaunch are the detail design, and in particular the power control and the
ease of driving.
I think that when the quality of winch driving is less than perfect it is
due to one or more of the following factors:
1/ Bad driving.
2/ A winch that is difficult to drive.
3/ Difficult conditions.
For instance, one site I know has trees on the borders, so whenever there is
any wind there is marked turbulence and gradient just at the height where
the glider is rotating into the full climb.
It is easier to drive the Skylaunch well compared with other types of winch.
I do not know how the heights we get at the Mynd
http://www.longmynd.com/
compare to the length available. We tend to be reasonably conservative in
our driving and flying methods, that is we leave a bit in hand. We
practically never break weak links, and we try to fly some way from the edge
in rotating into the full climb. Sites with restricted runs sometimes have
to try harder.
W.J. (Bill) Dean (U.K.).
Remove "ic" to reply.
"Bob Johnson" wrote in message
...
Bill, I appreciate the lead. Given the relatively high initial cost,
operating cost, and manning problems for a decent tug, 19,000 USD for a
new first-class winch doesn't seem unreasonable, particularly since they
can go for years with mostly only fuel cost to consider. And since
practically any club member can be quickly taught to drive a well
thought out winch, it's a wonder they are not more popular. I see that
Skylaunch has chosen to follow Craig's example in choosing the big-block
GM V-8 engine 8') while Supacat is sticking with the 250 hp Diesel.
We were hoping for the magic 2000-ft light wind launch height. Given our
5000 ft runway length, Plasma rope and a 20 kt wind, we may make it yet.
What fraction of the runway length in launch height are you getting with
these high powered winches?
Thanks and best regards,
Bob Johnson.