At 20:39 27 July 2009, Bruce wrote:
Look at what MEL does -

http://www.machinefabriek-el.nl/content_16.asp

This is the manufacturer to the reasonably conventional "Leopard" winch

and of the "van Gelder" - probably the most sophisticated winch
actually
working.

I wonder what proportion they are made in.

But anyway - as examples.
Note the engines are Volvo Penta diesel...
And they measure lots of things, and still get manually driven - albeit
with exquisite control.

Interestingly there are reports of clubs reverting from van Gelder to
Skylaunch (or equivalent) with retrieve setups with better launch rates.

Something to do with complexity and maintainability and cost. Any one
with actual experience?

Bruce

I flew off a Munster Van Gelder winch for 10 years and when it was working
it gave the smoothest launches I have ever had. It was fitted with
automatic drum engagement which was permanently switched off as the
drivers could do the selection much more efficiently. The control systems
were very very complex and it required many hours of maintenance during
the week to make sure it would run for the weekend. If it had been a
private club it would never have worked but the Royal Air Force had the
manpower to keep it maintained. Despite this many of the advanced systems
did not work. The winch drivers however were well trained and in the main
skillful so they worked round many of the minor problems. The winch was a
perfect example of a complex and technically advanced machine which did
not stand up to the rigors of being operated in the real world, it was
just too complex. Following that I flew for 7 years at a club using a
Skylaunch. The ability to accelerate the glider was not much less than the
MVG but it was nowhere near as smooth. The engineering was simple, one
could say agricultural, but that was it's main saving, there was nothing
complex to go wrong. The winch was made up of well tried and test indusrty
standard units which worked even with minimal servicing and I do mean
minimal. The only critisism I would make is that some of the engineering
was not agricultural enough to stand up to the abuse of club member winch
drivers. Bits fell off from time to time but the the winch engine,
transmission and drums continued to work and work well.

The MVG winch and the Skylaunch winch do the same job but the MVG does it
with much less effort. The MVG has 6 drums and it was a minor miracle if
they were all available for use. It drank deisel like there was no
tomorrow.
The Skylaunch has two drums and you could purchase 2 Skylaunch winches = 4
drums for the same amount the RAF paid for the MVG 15-20 years ago.

My current club operates a Supercat winch modified by Skylaunch to take
their engine, transmission and control. It is certainly as good as a
standard Skylaunch and has almost no downtime. They all run on LPG. (It's
what passes for cheap fuel in the UK)
With winches I believe that the KISS principle is essential