The petrol(gasoline)/propane winches at the Midland Club, Long Mynd were
bought new already converted for use with propane. They are large block
General Motors engines intended for marine use, where I understand propane
engines are common. I am practically certain that Skylaunch use the same
engines.

The advantage of petrol(gasoline)/propane engines does not lie only with
fuel cost. The engine itself is cheaper, and it is lighter in weight and
more compact. This means that the whole winch is smaller, lighter and more
compact. The Skylaunch can be towed legally on the road by any decent
4 X4, whereas the Supacat and all the other diesel winches I have seen can
only be moved on the back of a truck, or have to be built onto a truck
chassis. Changing the engine or working on it is also much easier.

Lastly it is much easier to arrange good throttle control and response with
a petrol/propane engine. One important special feature of the Skylaunch is
the throttle arrangement to help the driver get the correct setting for
different gliders and different conditions, the universal experience is that
this works really well.

If there is no cost advantage with propane, all the other reasons for
choosing petrol(gasoline) still apply. I know nothing about altitude
compensation, the Long Mynd is the highest club in the U.K. at
1,400 ft. a.s.l.

The normal size wire used in the U.K. seems to be 4.5 mm, some clubs use
5 mm.

W.J. (Bill) Dean (U.K.).
Remove "ic" to reply.


"Bill Daniels" wrote in message
...

Robin, Ged, for the UK, LPG is the right choice.

In the USA LPG or propane is still used mainly for domestic heating and
cooking and is sold for that purpose. To convert a spark ignition engine
to LPG is an extra $3000 or so and then fuel availability becomes an
issue. It can be done and it would work as well here as in the UK but
there's no cost reason to do it since LPG costs about the same or greater
than petrol.

Diesels are reasonably cheap here and the fuel is readily available as
untaxed "red diesel" for as little as $1 per gallon. Biodiesel is a bit
more. In the USA fuel cost for a glider winch is a non-issue
contributing as little as $0.10 per launch. The "big" consumable item in
the launch cost is cable replacement at about $1 per launch. I like
turbo diesels mainly for their flat torque curve and the altitude
compensation.

Not related to winches, but I once watched a demonstration of running a
standby diesel generator on natural gas. Basically, they just piped the
natural gas into the engine's air inlet. When they opened the natural
gas valve, the engine governor cut back on the diesel fuel to compensate
for the extra BTU's from the natural gas. The small amount of diesel
fuel still consumed was just for ignition.

Bill Daniels


"Robin Birch" wrote in message
...

I second this. My club (Cotswold) has used reverse auto tow, then
Skylaunch. I have flown recently using Supercat. The Skylaunch wins
hand down in both height and reliability/consistency. I also have a
fair amount of experience driving the Skylaunch and know that it is very
flexible and allows good control of light gliders (Ka8), gliders with a
narrow speed range (SHK) and heavy beasts ASH and so on.

LPG also works well in terms of cost and refuelling.

Regards

Robin


In message , Ged McKnight
writes

Sorry guys

But I think you are all looking in the wrong direction
re diesel winch launches......

I have read the previous 40 something posts on this
subject but no one has mentioned the LPG route, gives
both the acceleration of petrol with the cost savings
of diesel.


www.skylaunch.co.uk is a web site of a manufacturer
of a petrol/LPG driven winch of which I can give a
personal recommendation of being the best winch I have
operated over the last 25 years, as I have flown mainly
from winch sites then I consider myself an expert (
ex as in has been and spert as something under pressure)
I also am expecting at least a bottle of single malt
from my 'friends' at skylaunch ;-))

Ged