Winch operations

Fellow glider pilots,

First, I apologize for the length of this post. Our
club has acquired a new powerful 2-drum winch, and
I've been wondering about how to best operate it.
We have operated an older single drum winch successfully,
which works but is apparently a bit weak. We have
about 3800 feet for winch use. 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. Following, in no particular order, are some
of these questions:

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? It seems possible that
the lines, being under tension from both ends, will
come down quicker than the glider does. Looking from
the glider viewpoint of making a safe landing somewhere
on the field, regardless of runways, there is a possibility
of running over the towlines. We don't have skid-equipped
gliders any more, so that really shouldn't be a problem,
but I could see the lines catching on gear doors, etc.

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. That would keep the retreive line out
of line with the glider, at least until the glider
got off, then the weight of the strop would make it
hang below the glider. 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.

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. I would see it as the main winch operator
being in command, and telling the retreive winch operator
what to do. Maybe a command sequence something like:
(main to retreive) Ready to launch
(retreive to main) winch drum in neutral
Main winch starts launch
Glider releases
(main to retreive) Glider overhead, apply brake
(to stop the retreive drum from overrunning)
(main to retreive) Glider off, main winch in neutral,
begin retreive
(retreive to main) 500' left, begin braking
(to stop the main drum from overrunning)
(retreive to main) Retreive complete

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?
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.

What kind of line do you use on the retreive winch?
By my crude calculations, I think we would need at
least 4500' of retreive cable, maybe 5000'.

Am I making this too complicated? Speed of operations
is nice, but safety comes first.

I know there are people or clubs out there who are
already doing this safely and successfully. If you
could point to, or send me, any operations manuals
or procedures, I'd appreciate it.

Thanks,
Ed

Hi,

Any chance you bought the winch from the Memphis club? If so, that winch
was designed and built by Glenn Lawler, the founder of our club,
Southern Eagles Soaring. I used to be the main winch driver. It's really
a great winch. We never got around to finishing it out. It was supposed
to have controls to switch drums from inside the cab. Another feature
that it needed but we never got around to was some sort of device to
apply a small amount of braking to the drum when paying out line. As it
is, the driver has to lightly ride the brake to manage drum inertia when
reeling out line. I also wanted to go to a long hand lever for the
throttle.

The Memphis club installed a "Plasma" line (like Spectra) on one drum.
Surprisingly, it didn't really increase launch height, but it did have
one very major advantage over cable. It had so little stretch, that it
didn't store energy like steel cable. Steel cable would snatch back
violently on a cable break and throw itself into a tangle. The synthetic
rope would just drop with almost no snap back. Very little chance of
throwing a "birds nest".

I spoke to Derek Piggot once about the retrieve winch. He said they used
heavy monofilament line (fishing line) on the retrieve winch. I seem to
remember that the retrieve winch was something like a 5 hp
Briggs&Stratton type affair. I think it had a centrifugal clutch, like a
go-cart so that it would free wheel. Using a retrieve winch would
certainly speed things up and reduce cost. We used to do 20-40 launches
a day. At 3000 feet both ways, the mileage on a tow car really adds up.

All the best,

Wallace

Wallace,

Yes, that's the one. First, let me say that I don't
represent my club, so anything I say in this thread
is my thought alone. There are people smart about
winching in our club, I'm just trying to learn, and
maybe contribute something to the group.

The first thing I heard about this winch was that we'd
remove the cable and replace it with something like
the 'Plasma' on the other drum. Do you know how long
those lines are?

I was thinking about the retreive winch, and it seems
to me that our old winch will be serious overkill,
if it would even work. My gut feel is that something
like a snowmobile engine with a centrifugal clutch
would work, if that's enough power. What would you
use for a drum?

I was also thinking about using the parts of some small
car, like a Geo Metro, which has a 3-cyl front drive
system, maybe about 1 liter. I'd modify the differential
by welding the spider gears solid, so that you could
run with only one axle, and keep the seat and engine
as is. Probably take off the roof, and build a lexan
protective shield with expanded metal mesh over it
to keep the driver and possibly trainee safe from mishaps.
Might even be able to use either an original wheel,
or some different larger wheel without a tire as the
retreive drum. Brakes would already be there, just
stop off the lines for the 3 wheels that are removed.
Use the foot throttle and brake. Have to make a guillotine,
unless there are commercial ones for sale. If I wanted
to, I could do something like that myself, I'm pretty
sure. I could make it something that I could haul
in the back of my (or any) pickup, or tow behind.
I'd imagine I could find such a car at a junkyard,
wrecked in the rear, but with the front intact. Remove
all the parts I don't need, leave all the wiring intact,
and hook the steering gear up to rotate the winch within
a small range to allow some kind of aiming to keep
it pointed at the chute, and maybe act somewhat as
a level wind. How much tension do you suppose is required
to retreive? Any idea of what kind of speeds would
be used? Seems like you would use enough to keep the
chute full, and maybe the line in the air as long as
possible.

Ed

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).

--
Wojtus.net

Originally Posted by Wallace Berry

Hi,

Any chance you bought the winch from the Memphis club?

The Memphis club installed a "Plasma" line (like Spectra) on one drum.
Surprisingly, it didn't really increase launch height, but it did have
one very major advantage over cable.

Wallace

Hiya Wallace,

A few of us here at Memphis Soaring really enjoyed your winch. Unfortunately, it was only a few of us so the club decided to part with it. I hope the Philly club will get good use out of it.

Another advantage of the synthetic line is that we never once had a rope break during a launch (although we broke a ton of weak links in the early days.) The only time I'm aware of breaking the line was when it piled straight down on top of the winch and got wrapped around the works before we could stop the drum spining.

Hope to see you at a GTA event this spring,

To answer one of the original questions: the line was never a factor in any of my low releases. It falls cleanly away while you are still pushing the nose over. I've had to get off for various reasons several times below four or five hundred feet and never had a problem getting down safely. If you are too high to land straight ahead, you should have enough altitude to turn back, of course I know nothing about your home field, so YMMV.

Steve

Edward,

congratulations to your new winch. I looked at the posted photos but
couldn't figure out how the drums were selected. Maybe at a future
time, you can describe the system to me.
Join the yahoo group 'winchdesign' . You will find all sorts of helpful
information about winch operation there.

Ulrich Neumann

In article ,
Vic7 wrote:

Wallace Berry Wrote:
Hi,

Any chance you bought the winch from the Memphis club?

The Memphis club installed a "Plasma" line (like Spectra) on one drum.
Surprisingly, it didn't really increase launch height, but it did have
one very major advantage over cable.

Wallace

Hiya Wallace,

A few of us here at Memphis Soaring really enjoyed your winch.
Unfortunately, it was only a few of us so the club decided to part with
it. I hope the Philly club will get good use out of it.

Another advantage of the synthetic line is that we never once had a
rope break during a launch (although we broke a ton of weak links in
the early days.) The only time I'm aware of breaking the line was when
it piled straight down on top of the winch and got wrapped around the
works before we could stop the drum spining.

Hope to see you at a GTA event this spring,

To answer one of the original questions: the line was never a factor
in any of my low releases. It falls cleanly away while you are still
pushing the nose over. I've had to get off for various reasons several
times below four or five hundred feet and never had a problem getting
down safely. If you are too high to land straight ahead, you should
have enough altitude to turn back, of course I know nothing about your
home field, so YMMV.

Steve

I was sorry to see the winch go. Sorry you guys had to sell it as well.
You have a great field for winching. I hope the new owners will get good
use of it.

Glen Klingshirn and I really enjoyed visiting your field and doing the
winch training. Until recently I was still wearing the Memphis Soaring
Society hat that you guys gave me. Unfortunately, a branch knocked it
off my head while I was bush hogging the other day and the brush cutter
got it. I still have a T-shirt though!

I think your experience with the Plasma rope is valuable for all of us,
both for winching and auto launching. You should write up a short
article on it and post it here.

Hope you guys are off to a great soaring season. We're in a drought here
in Alabama, so we are looking forward to some good soaring after last
year's soggy spring and summer.

Hello:
You guys might want to have a look at a new Yahoo Group
http://groups.yahoo.com/group/pulleylaunch/ there is a wealth of info
on ground launching.
Have Fun
Rusty

Wallace Berry wrote:
In article ,
Vic7 wrote:

Wallace Berry Wrote:
Hi,

Any chance you bought the winch from the Memphis club?

The Memphis club installed a "Plasma" line (like Spectra) on one drum.
Surprisingly, it didn't really increase launch height, but it did have
one very major advantage over cable.

Wallace

Hiya Wallace,

A few of us here at Memphis Soaring really enjoyed your winch.
Unfortunately, it was only a few of us so the club decided to part with
it. I hope the Philly club will get good use out of it.

Another advantage of the synthetic line is that we never once had a
rope break during a launch (although we broke a ton of weak links in
the early days.) The only time I'm aware of breaking the line was when
it piled straight down on top of the winch and got wrapped around the
works before we could stop the drum spining.

Hope to see you at a GTA event this spring,

To answer one of the original questions: the line was never a factor
in any of my low releases. It falls cleanly away while you are still
pushing the nose over. I've had to get off for various reasons several
times below four or five hundred feet and never had a problem getting
down safely. If you are too high to land straight ahead, you should
have enough altitude to turn back, of course I know nothing about your
home field, so YMMV.

Steve

I was sorry to see the winch go. Sorry you guys had to sell it as well.
You have a great field for winching. I hope the new owners will get good
use of it.

Glen Klingshirn and I really enjoyed visiting your field and doing the
winch training. Until recently I was still wearing the Memphis Soaring
Society hat that you guys gave me. Unfortunately, a branch knocked it
off my head while I was bush hogging the other day and the brush cutter
got it. I still have a T-shirt though!

I think your experience with the Plasma rope is valuable for all of us,
both for winching and auto launching. You should write up a short
article on it and post it here.

Hope you guys are off to a great soaring season. We're in a drought here
in Alabama, so we are looking forward to some good soaring after last
year's soggy spring and summer.