New winch height record

As an aside,
back in 88 we at 611 VGS at RAF Swanton Morley flew from legal sun up to
legal sun down on the longest day.
Utilising our Van Gelder 6 drum winch and 6 GROB 103's achieved in
excess of our 611 launches in a single day target.
Logistics were fun but just demonstrated what is possible.

Phil


Bill Daniels wrote:
"Martin Gregorie" wrote in message
news
For short runways, a single drum and a retrieve winch is probably
unbeatable.

I know about them but have never seen one in action. How long can the run
be before this becomes impractical?


Not sure - somebody needs to do some believable side by side tests. The UK
retrieve winch operations are still using steel cables on fairly short runs.
Those don't seem to suffer much from lifting two cables. Obviously, Dyneema
cables will have a large effect on retrieve winch operations by reducing the
losses associated with lifting a second cable.

It depends on what you are trying to do. Landing practice or launching into
local ridge lift makes launch frequency the most important thing so retrieve
winches are attractive there. Getting high enough to cruise around for a
while looking for thermals probably means long runs and multiple drums are a
better approach.

Very high launches for training probably eliminates retrieve winches from
consideration.

Bill Daniels

611 launches in one day with one winch! Wow! I think that's a world
recond.

Bill Daniels


"Phil Collin" wrote in message
...
As an aside,
back in 88 we at 611 VGS at RAF Swanton Morley flew from legal sun up to
legal sun down on the longest day.
Utilising our Van Gelder 6 drum winch and 6 GROB 103's achieved in excess
of our 611 launches in a single day target.
Logistics were fun but just demonstrated what is possible.

Phil


Bill Daniels wrote:
"Martin Gregorie" wrote in message
news
For short runways, a single drum and a retrieve winch is probably
unbeatable.

I know about them but have never seen one in action. How long can the
run be before this becomes impractical?


Not sure - somebody needs to do some believable side by side tests. The
UK retrieve winch operations are still using steel cables on fairly short
runs. Those don't seem to suffer much from lifting two cables.
Obviously, Dyneema cables will have a large effect on retrieve winch
operations by reducing the losses associated with lifting a second cable.

It depends on what you are trying to do. Landing practice or launching
into local ridge lift makes launch frequency the most important thing so
retrieve winches are attractive there. Getting high enough to cruise
around for a while looking for thermals probably means long runs and
multiple drums are a better approach.

Very high launches for training probably eliminates retrieve winches from
consideration.

Bill Daniels

"bagmaker" schrieb im Newsbeitrag
...

A typical winch launch yeilds about 1/3 of the runway/field available,
this is a fantastic result, Bill!
Perhaps we should be measuring the launch as a percentage of field
length, then there would actually be a record available for everyone to
shoot for, regardless of locality.
So...
With a runway of 3100m and a launch of 1718, the current known record
is 55.42%


Get out there and break it!!

950m steel cable + 350hp winch + 20km/h wind + ASK21 = 750m or 78%.
More high was possible, but airspace class C begins at 750m above our
airfield so I had to release the cable.

I think the ASK21 gets the best high on winchlaunch. Our DG1000 always gets
25% less high.

Greetings,
Sönke

On Nov 28, 6:22 pm, "Sönke Gutzlaff" wrote:
950m steel cable + 350hp winch + 20km/h wind + ASK21 = 750m or 78%.
More high was possible, but airspace class C begins at 750m above our
airfield so I had to release the cable.

I think the ASK21 gets the best high on winchlaunch. Our DG1000 always gets
25% less high.

Greetings,
Sönke

Sönke, what speed do you fly at on the winch, and how much back
pressure do you apply to the stick?


Dan

Back in Germany we used two twin drum Tost winches on our field and
launched all day long back to back, as long as there were planes
needing to be launched. Wires were retrieved with a retrieve vehicle,
two at a time.

I think the British method of using a single drum winch in combination
with a retrieve winch to be a very sensible idea - even for long
fields and high launches.

The cable is being retrieved before it even hits the ground. So the
retrieve process is shorter and faster than using a retrieve vehicle
by dragging the entire cable length along the ground. The winch
retrieve should there for also save on wear and tear on the cable as
most of th retrieve occurs in the air after the glider releases.

On very high tows, a long portion of the cable is never wound up into
the tow drum and there for a high altitude launch should actually
reduce the cable retrieve process using a cable retrieve winch. The
light weight of the newer cables makes a launch penalty negligible.
The retrieve cable need not be very strong or even in good shape
anyway, as it's only function is to retrieve the cable.

I like this approach and seems the cheapest way to introduce high
frequency winch operations in the USA. I wish Commercial Glider
Operators would buy a single drum winch and a retrieve winch and offer
this launch method. Even at 10-15 a launch - it's still heaps cheaper
and the operator would probably make more money at the end of the day.

Not to speak about the fact that winch launches a far and away more
fun and exiting than aero tows.

It could be you're right but I'd still like to see an actual comparison with
and without the retrieve winch at longer and longer distances. Some
validated metrics would help sell the idea. It has yet to be determined
just how long ropes can be with a retrieve winch.

What I'm worried about isn't the weight of Dyneema/Spectra ropes it's the
pull angle at the hook. If the retrieve rope drags back enough to change
that angle it will adversely affect the height achieved.

I know an engineer who was working on a simple "spinner reel" type design
for a retrieve winch that would use 1 or 1.5mm Dyneema. Calculations showed
that the power required is minimal - you could power it with a small car
starter motor and a battery. 2000 meters of thin Dyneema would fit on a
drum not much bigger than a coffee can. With the "spinner reel" concept
Dyneema would pay off the retrieve winch with no rotation of the tiny drum.

On the bright side, using a retrieve winch would cut the fuel use by half.

Bill Daniels


"tommytoyz" wrote in message
...
Back in Germany we used two twin drum Tost winches on our field and
launched all day long back to back, as long as there were planes
needing to be launched. Wires were retrieved with a retrieve vehicle,
two at a time.

I think the British method of using a single drum winch in combination
with a retrieve winch to be a very sensible idea - even for long
fields and high launches.

The cable is being retrieved before it even hits the ground. So the
retrieve process is shorter and faster than using a retrieve vehicle
by dragging the entire cable length along the ground. The winch
retrieve should there for also save on wear and tear on the cable as
most of th retrieve occurs in the air after the glider releases.

On very high tows, a long portion of the cable is never wound up into
the tow drum and there for a high altitude launch should actually
reduce the cable retrieve process using a cable retrieve winch. The
light weight of the newer cables makes a launch penalty negligible.
The retrieve cable need not be very strong or even in good shape
anyway, as it's only function is to retrieve the cable.

I like this approach and seems the cheapest way to introduce high
frequency winch operations in the USA. I wish Commercial Glider
Operators would buy a single drum winch and a retrieve winch and offer
this launch method. Even at 10-15 a launch - it's still heaps cheaper
and the operator would probably make more money at the end of the day.

Not to speak about the fact that winch launches a far and away more
fun and exiting than aero tows.

Bill,

At Lasham we still use vehicle retrieves and a 2 drum
main winch set up on days or evenings when demand for
winch launches is low, say when we are operating 5
gliders or less. Also the last launch of the day is
always done without the retrieve winch connected so
that we can wind the cable fully into the main winch.
Although I don't have a large data set, comparisions
between the last two launches of the day suggest that
we lose about 80 feet off a typical 1600 ft launch
due to the retrieve winch, which is 5%. This is using
steel cables on both winches. We have used an all synthetic
cable set up in the past when the losses were almost
negligible. Only problem was that the small diameter
synthetic cable on the retrieve winch wore out within
6 weeks due to ground abrasion!

I can't see that there should be any realistic limits
on the length of retrieve cable, as long as you can
keep it light - see UHMWPE cable below. However sideways
drift in a crosswind needs to be a consideration. You
may need a very wide as well as a very long airfield.
The retrieve cables we use are about half the diameter
of the main cables, so only weigh a quarter of the
amount for a given length. The back pull may initiate
a slightly earlier back release,

Our retrieve winch is fitted with a 1.9 litre industrial
VW engine developing about 90 hp, and even that labours
a bit during the retrieve (even with synthetic cables)
so the starter motor idea, if you will excuse the pun,
is a non-starter!

UHMWPE cable, such as Spectra, Plasma or Dyneema (trade
names) is pretty amazing stuff. It looks like washing
line, but is stronger than steel whilst being 10 times
lighter. Unfortunately it is also about five times
more expensive than the equivalent steel cable and
requires modifications to the winch. For the lengths
of winch run we use, normally about 4200ft, it wasn't
found to give that much improvement in height, less
than 100ft, and was deemed by our Committee not to
be cost effective. It would certainly come into its
own on 5000 feet or longer runs, when steel cable starts
to become significantly heavy.

Del Copeland

At 23:12 28 November 2007, Bill Daniels wrote:
It could be you're right but I'd still like to see
an actual comparison with
and without the retrieve winch at longer and longer
distances. Some
validated metrics would help sell the idea. It has
yet to be determined
just how long ropes can be with a retrieve winch.

What I'm worried about isn't the weight of Dyneema/Spectra
ropes it's the
pull angle at the hook. If the retrieve rope drags
back enough to change
that angle it will adversely affect the height achieved.

I know an engineer who was working on a simple 'spinner
reel' type design
for a retrieve winch that would use 1 or 1.5mm Dyneema.
Calculations showed
that the power required is minimal - you could power
it with a small car
starter motor and a battery. 2000 meters of thin Dyneema
would fit on a
drum not much bigger than a coffee can. With the 'spinner
reel' concept
Dyneema would pay off the retrieve winch with no rotation
of the tiny drum.

On the bright side, using a retrieve winch would cut
the fuel use by half.

Bill Daniels


'tommytoyz' wrote in message
.
com...
Back in Germany we used two twin drum Tost winches
on our field and
launched all day long back to back, as long as there
were planes
needing to be launched. Wires were retrieved with
a retrieve vehicle,
two at a time.

I think the British method of using a single drum
winch in combination
with a retrieve winch to be a very sensible idea -
even for long
fields and high launches.

The cable is being retrieved before it even hits the
ground. So the
retrieve process is shorter and faster than using
a retrieve vehicle
by dragging the entire cable length along the ground.
The winch
retrieve should there for also save on wear and tear
on the cable as
most of th retrieve occurs in the air after the glider
releases.

On very high tows, a long portion of the cable is
never wound up into
the tow drum and there for a high altitude launch
should actually
reduce the cable retrieve process using a cable retrieve
winch. The
light weight of the newer cables makes a launch penalty
negligible.
The retrieve cable need not be very strong or even
in good shape
anyway, as it's only function is to retrieve the cable.

I like this approach and seems the cheapest way to
introduce high
frequency winch operations in the USA. I wish Commercial
Glider
Operators would buy a single drum winch and a retrieve
winch and offer
this launch method. Even at 10-15 a launch - it's
still heaps cheaper
and the operator would probably make more money at
the end of the day.

Not to speak about the fact that winch launches a
far and away more
fun and exiting than aero tows.

On Nov 29, 4:23 am, Del C
wrote:
UHMWPE cable, such as Spectra, Plasma or Dyneema (trade
names) is pretty amazing stuff. It looks like washing
line, but is stronger than steel whilst being 10 times
lighter. Unfortunately it is also about five times
more expensive than the equivalent steel cable and
requires modifications to the winch. For the lengths
of winch run we use, normally about 4200ft, it wasn't
found to give that much improvement in height, less
than 100ft, and was deemed by our Committee not to
be cost effective. It would certainly come into its
own on 5000 feet or longer runs, when steel cable starts
to become significantly heavy.

From a winch driver's point of view, I've always thought that the most
appealing aspect of UHMWPE is it's pleasant handling - it's light,
doesn't "ping back" if released under tension (which can be disastrous
with steel), and doesn't cut your hands, and you can use much smaller,
cheaper and more fuel-efficient retrieve vehicles. On the other hand,
from the reports I've heard, the winch needs to be set up *perfectly*
or the expensive cable can be ruined in one launch. It's also a
_little_ trickier to repair when it does break, though nothing that
proper training can't handle.

The main issues with UHMWPE seem to be two-fold: the initial cost of
modifying a winch to use the cable, and the lifetime vs. cost ratio.
Right now, UHMWPE doesn't seem to last as many times longer than
steel, as as many times it costs to buy versus steel.


Dan

On 28 Nov., 22:15, Dan G wrote:
On Nov 28, 6:22 pm, "Sönke Gutzlaff" wrote:

950m steel cable + 350hp winch + 20km/h wind + ASK21 = 750m or 78%.
More high was possible, but airspace class C begins at 750m above our
airfield so I had to release the cable.

I think the ASK21 gets the best high on winchlaunch. Our DG1000 always gets
25% less high.

Greetings,
Sönke

Sönke, what speed do you fly at on the winch, and how much back
pressure do you apply to the stick?

Dan

We broke this record with 1718 Meter and a 3030 Meter runway (winch
length)
With NO wind condition. (sometimes even tailwind)
In the spring we do some more attempts for a higher record.
Then we wait for better wind/weather conditions.
We had a Notam and a privat airspace till FL70 for the lost month. on
our next attempts we hope to disconnect the cable at FL70

A winch start to 1718 Meter or a higher has some problems to overcome.
Think about wind directions at higher altitudes sometimes 180 degrees
different from ground wind.
Think about the cloud base. in most of the attempts we had to abort
the winchstart halfway due the lower cloudbase.
What happens if the cable brakes at high altitudes?

The winchstart itself takes about 2 min 20 sec. then you still have
about one minute to winch up the rest off the cable.
driving the cable back to the start position, takes about ten minutes,
so a high production would be difficult.

We had a Notam and a privat airspace till FL70 for the lost month. on
the next attempt

"Del C" wrote in message
...
Bill,

At Lasham we still use vehicle retrieves and a 2 drum
main winch set up on days or evenings when demand for
winch launches is low, say when we are operating 5
gliders or less. Also the last launch of the day is
always done without the retrieve winch connected so
that we can wind the cable fully into the main winch.
Although I don't have a large data set, comparisions
between the last two launches of the day suggest that
we lose about 80 feet off a typical 1600 ft launch
due to the retrieve winch, which is 5%. This is using
steel cables on both winches. We have used an all synthetic
cable set up in the past when the losses were almost
negligible. Only problem was that the small diameter
synthetic cable on the retrieve winch wore out within
6 weeks due to ground abrasion!

I can't see that there should be any realistic limits
on the length of retrieve cable, as long as you can
keep it light - see UHMWPE cable below. However sideways
drift in a crosswind needs to be a consideration. You
may need a very wide as well as a very long airfield.
The retrieve cables we use are about half the diameter
of the main cables, so only weigh a quarter of the
amount for a given length. The back pull may initiate
a slightly earlier back release,

Our retrieve winch is fitted with a 1.9 litre industrial
VW engine developing about 90 hp, and even that labours
a bit during the retrieve (even with synthetic cables)
so the starter motor idea, if you will excuse the pun,
is a non-starter!

UHMWPE cable, such as Spectra, Plasma or Dyneema (trade
names) is pretty amazing stuff. It looks like washing
line, but is stronger than steel whilst being 10 times
lighter. Unfortunately it is also about five times
more expensive than the equivalent steel cable and
requires modifications to the winch. For the lengths
of winch run we use, normally about 4200ft, it wasn't
found to give that much improvement in height, less
than 100ft, and was deemed by our Committee not to
be cost effective. It would certainly come into its
own on 5000 feet or longer runs, when steel cable starts
to become significantly heavy.

Del Copeland

We actually tested the power required to retrieve Spectra and the starter
motor is way more powerful than needed. Not sure what your problem is at
Lasham.

The cost of Spectra is more like three times the cost of steel not 5 times -
I checked the prices this morning. It takes a LOT of power to pull steel
cable across an airfield - I can pull a mile of Spectra with one finger.

We need verifiable data from retrieve winches. Your tests at Lasham are not
verifiable since you did no controlled experiments.

Bill Daniels