User Edward Winchester wrote:

There has been some
talk about using the old winch for a retreive winch,
and using only one drum of the new winch, and that
has prompted all these questions. I've read Piggot's
Ground Launches book, and he barely mentions retreive
winching.
Retrieve winches were very common in Poland decades ago, when a car was
an absolute luxury. Times have changed, and we've abondoned winch
retrievers - they caused too much problems. Most (or even all) clubs are
now using old cars performing shuttle-service between glider grid and
the winch.

What about emergencies? Suppose the glider releases
or the rope breaks at 400'? Will those lines up in
the air cause any difficulty for the glider, or any
possibility of interference?
They won't. As single rope falls fast enought to be on the ground way
before the glider, two connected ropes will fall down even faster.

Another thing, what keeps the glider from running over
the retreive line on takeoff? I suppose that would
be prevented by, for example, having the takeoff point
where it usually is, even with the middle of the driveway,
but having the retreive winch offset a few dozen yards
to one side.
Yes, retrieve winch were placed with an offset. 10m to the side, and
about 15m behind the glider's winch hook.

This might make the retreive
winch need some kind of steering device, maybe made
from a car steering system, which would keep the winch
pointing at the glider/parachute.
Retrieve rope has no significant tension, so standard rope-driving
mechanisms handle it easy even if the rope direction differs by 20-40
degrees of the main rope axis. A good placement of the retriever is
enought, no steering needed.

Yet another thing, it seems that doing this right will
require more communications between the two winch operators
than the simple radio checks from one winch to the
glider. [...]
Yeah, coordination between operators was a big and pain-in-the-rudder
issue

Glider releases
(main to retreive) Glider overhead, apply brake
(to stop the retreive drum from overrunning)
Retrieve winches were equipped with automatic brake which reacted to
rope's tension. Also note that retrieve drum and it's rope is much
lighter than main one, so overrunning is less likely (but still possible).

This would seem like a lot of communications to use
over the regular aviation frequencies. Has any thought
been given to using FRS radios for this function?
In 60's and 70's we've been using visual signals only

The main winch could have two different push-to-talk
buttons, one for glider communications, the other for
the FRS radio. I assume the winch operators would
be wearing headsets, which could be stereo, with the
two radio circuits in different ears, and mike switching
with relays based on which PTT switch was pressed.
I'm not sure the retreive winch operator needs to
talk on the glider channel, just to listen.
It's too complicated to work

What kind of line do you use on the retreive winch?
These were steel lines 2.5-3mm thick (while 4-5mm on the main winch).

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