Alistair, Hi! I certainly remember you. Didn't know where you went
after North Weald.

I have seen a recent posting which suggested that using the diff as the
drive for a winch drum on the axle and doubling the speed is not a
recipe for long life. As others have pointed out, a better long term
solution seems to be a proper rightangle drive (the crown wheel and
pinion seem fine for that) and dog clutches for the drum, one at a time
and at crown wheel speed.

I did not see your winchosaurus, but I believe that there have been an
amazing variety of winches over the years. The most eccentric I know of
were Freddie Wiseman's 1977 converted combine harvester at one end of
the scale, and a totally portable, demountable, device to bolt onto the
hub of a Rover car at the other extreme. The latter was a commercial
offering, again in the 1970's.

When we lost the use of wire launching at North Weald but had bought
Ridgewell and needed to acquire one or more winches, we tried a
converted bus. That had two axles, one above the other, rather than the
whole second chassis. It had one drive shaft which had to be
disconnected from the lower axle after driving the bus to the winch
point, and reconnecting it to the higher, drum, axle. IIRC it had dog
clutches. We didn't buy it because it was unreasonable expensive and
looked as though it was not a sufficiently long term solution for us.

I had seen a similar arrangement in 1970 when Essex's original winch was
an old truck with that idea. I had my first instructional launch from
it, one cold March morning when there was too much ice to autotow. Got
300 feet and a free second go, which was not much better.

Now, we have ended up with 4 ex-ATC winches bought at auction, getting
two reasonable ones from them plus a lot of spares, and replacing their
powertrains. One had a total cab transplant too, professionally built;
the other is in the course of having a lower cost replacement cab, made
by some of our members.

Regards - Chris.