Winching - Reverse Auto Tow

On Sunday, November 2, 2003 at 1:49:20 PM UTC-5, wrote:
Can anyone direct me to Clubs / Web sites using this method of launching -
Interested in finding out more about this method, particularly from clubs
that operate from gravel/dirt strips

Thank you


John Spargo

Bruce: I can give you some quantitative numbers. In 1966-67 I made ~70 car-pulley tows in a 1:26 at Dansville using an asphalt runway that is almost 4000ft in length. The average tow was to 1300ft with some tows to 1500ft when the wind was optimum. For comparison, in 2009 I gave many instruction winch flights in either a Blanik L13 or a ASK21 using the same runway at Dansville. The average tow again was 1300ft and 1500ft when the wind was favourable. Thus under similar circumstances car pulley and winch give essentially the same height. Winch tows can utilize the full length of the airfield whereas car pulley tows are limited to the length of the paved surface because of the damage caused driving on the grass. Also winch tows are less intrusive than car pulley if the airport has mixed power and glider activity.

Doug C

Does anyone have particularly bad experiences with pulleys used like this. I am talking about the pulleys themselves. Has someone found a particular diameter that is too small. Obviously larger is better for both bearing speed and rope bending, but there are limitations on cost and availability....particular for the trial run I'm thinking about. I am considering a trial run with a swiveling pulley on the receiver hitch of a pickup, no guides, just the pulley, with around 8,000' of 1/4" poly hollow braid, flying a 1-26. That should prove the launch height, assuming the rope doesn't break on the first launch. I'm not sure what to expect at the pulley end, and don't want the rope jumping out of the sheave, catching and breaking. I doubt it will, but have no experience to back it up.

On Tuesday, 26 July 2016 02:12:58 UTC+1, wrote:
Does anyone have particularly bad experiences with pulleys used like this.. I am talking about the pulleys themselves. Has someone found a particular diameter that is too small. Obviously larger is better for both bearing speed and rope bending, but there are limitations on cost and availability....particular for the trial run I'm thinking about. I am considering a trial run with a swiveling pulley on the receiver hitch of a pickup, no guides, just the pulley, with around 8,000' of 1/4" poly hollow braid, flying a 1-26. That should prove the launch height, assuming the rope doesn't break on the first launch. I'm not sure what to expect at the pulley end, and don't want the rope jumping out of the sheave, catching and breaking. I doubt it will, but have no experience to back it up.

Hi, I wrote an article "The Expedition Pilot's guide to launching" in the Dec2013/Jan 2014 edition of the UK Sailplane and Gliding magazine. It may be of interest. I use 12mm diameter high density polypropylene rope (Skyrope from Skylaunch) on snatch blocks with, initally steel pulleys on plain bearings 110mm dia. The bearings cooked in spite of lots of grease! These have been modified for regular use to nylon pulleys with steel ball bearings. The steel flaps or cheeks of the snatch blocks keep the rope where it should be. I use either a 2 to 1 or 3 to one system to keep the tow speed down ( we use some rough fields). If you are serious then I can send you a copy of the article and details of the kit, as well as the links to YouTube videos of some launches in the Lake District (UK) using 2 to 1 pulley system, with one pulley on a ground anchor and the other on the car's tow hitch (with the rope tail to another ground anchor). Everything used is inexpensive, and it works. Pete Whitehead

On Tuesday, July 26, 2016 at 1:51:14 AM UTC-6, Peter Whitehead wrote:
On Tuesday, 26 July 2016 02:12:58 UTC+1, wrote:
Does anyone have particularly bad experiences with pulleys used like this. I am talking about the pulleys themselves. Has someone found a particular diameter that is too small. Obviously larger is better for both bearing speed and rope bending, but there are limitations on cost and availability...particular for the trial run I'm thinking about. I am considering a trial run with a swiveling pulley on the receiver hitch of a pickup, no guides, just the pulley, with around 8,000' of 1/4" poly hollow braid, flying a 1-26. That should prove the launch height, assuming the rope doesn't break on the first launch. I'm not sure what to expect at the pulley end, and don't want the rope jumping out of the sheave, catching and breaking. I doubt it will, but have no experience to back it up.

Hi, I wrote an article "The Expedition Pilot's guide to launching" in the Dec2013/Jan 2014 edition of the UK Sailplane and Gliding magazine. It may be of interest. I use 12mm diameter high density polypropylene rope (Skyrope from Skylaunch) on snatch blocks with, initally steel pulleys on plain bearings 110mm dia. The bearings cooked in spite of lots of grease! These have been modified for regular use to nylon pulleys with steel ball bearings. The steel flaps or cheeks of the snatch blocks keep the rope where it should be. I use either a 2 to 1 or 3 to one system to keep the tow speed down ( we use some rough fields). If you are serious then I can send you a copy of the article and details of the kit, as well as the links to YouTube videos of some launches in the Lake District (UK) using 2 to 1 pulley system, with one pulley on a ground anchor and the other on the car's tow hitch (with the rope tail to another ground anchor). Everything used is inexpensive, and it works. Pete Whitehead

Pete, I watched your videos, and those look like strong launches! Much better acceleration than we typically see. If you could send me an electronic copy of your article, I would love to read it.

On Wednesday, July 27, 2016 at 3:28:38 AM UTC+12, wrote:
On Tuesday, July 26, 2016 at 1:51:14 AM UTC-6, Peter Whitehead wrote:
On Tuesday, 26 July 2016 02:12:58 UTC+1, wrote:
Does anyone have particularly bad experiences with pulleys used like this. I am talking about the pulleys themselves. Has someone found a particular diameter that is too small. Obviously larger is better for both bearing speed and rope bending, but there are limitations on cost and availability...particular for the trial run I'm thinking about. I am considering a trial run with a swiveling pulley on the receiver hitch of a pickup, no guides, just the pulley, with around 8,000' of 1/4" poly hollow braid, flying a 1-26. That should prove the launch height, assuming the rope doesn't break on the first launch. I'm not sure what to expect at the pulley end, and don't want the rope jumping out of the sheave, catching and breaking. I doubt it will, but have no experience to back it up.

Hi, I wrote an article "The Expedition Pilot's guide to launching" in the Dec2013/Jan 2014 edition of the UK Sailplane and Gliding magazine. It may be of interest. I use 12mm diameter high density polypropylene rope (Skyrope from Skylaunch) on snatch blocks with, initally steel pulleys on plain bearings 110mm dia. The bearings cooked in spite of lots of grease! These have been modified for regular use to nylon pulleys with steel ball bearings.. The steel flaps or cheeks of the snatch blocks keep the rope where it should be. I use either a 2 to 1 or 3 to one system to keep the tow speed down ( we use some rough fields). If you are serious then I can send you a copy of the article and details of the kit, as well as the links to YouTube videos of some launches in the Lake District (UK) using 2 to 1 pulley system, with one pulley on a ground anchor and the other on the car's tow hitch (with the rope tail to another ground anchor). Everything used is inexpensive, and it works. Pete Whitehead

Pete, I watched your videos, and those look like strong launches! Much better acceleration than we typically see. If you could send me an electronic copy of your article, I would love to read it.

Yes, the launches shown here look like normal launches from a pretty powerful winch, not the average rather anaemic direct-pull car launch. Sadly, we don't see anything of the vehicle or launch setup

https://www.youtube.com/channel/UC_G...WaGdMMduefDVAg

On Tuesday, July 26, 2016 at 9:44:26 AM UTC-6, Bruce Hoult wrote:
On Wednesday, July 27, 2016 at 3:28:38 AM UTC+12, wrote:
On Tuesday, July 26, 2016 at 1:51:14 AM UTC-6, Peter Whitehead wrote:
On Tuesday, 26 July 2016 02:12:58 UTC+1, wrote:
Does anyone have particularly bad experiences with pulleys used like this. I am talking about the pulleys themselves. Has someone found a particular diameter that is too small. Obviously larger is better for both bearing speed and rope bending, but there are limitations on cost and availability...particular for the trial run I'm thinking about. I am considering a trial run with a swiveling pulley on the receiver hitch of a pickup, no guides, just the pulley, with around 8,000' of 1/4" poly hollow braid, flying a 1-26. That should prove the launch height, assuming the rope doesn't break on the first launch. I'm not sure what to expect at the pulley end, and don't want the rope jumping out of the sheave, catching and breaking. I doubt it will, but have no experience to back it up.

Hi, I wrote an article "The Expedition Pilot's guide to launching" in the Dec2013/Jan 2014 edition of the UK Sailplane and Gliding magazine. It may be of interest. I use 12mm diameter high density polypropylene rope (Skyrope from Skylaunch) on snatch blocks with, initally steel pulleys on plain bearings 110mm dia. The bearings cooked in spite of lots of grease! These have been modified for regular use to nylon pulleys with steel ball bearings. The steel flaps or cheeks of the snatch blocks keep the rope where it should be. I use either a 2 to 1 or 3 to one system to keep the tow speed down ( we use some rough fields). If you are serious then I can send you a copy of the article and details of the kit, as well as the links to YouTube videos of some launches in the Lake District (UK) using 2 to 1 pulley system, with one pulley on a ground anchor and the other on the car's tow hitch (with the rope tail to another ground anchor). Everything used is inexpensive, and it works. Pete Whitehead

Pete, I watched your videos, and those look like strong launches! Much better acceleration than we typically see. If you could send me an electronic copy of your article, I would love to read it.

Yes, the launches shown here look like normal launches from a pretty powerful winch, not the average rather anaemic direct-pull car launch. Sadly, we don't see anything of the vehicle or launch setup

https://www.youtube.com/channel/UC_G...WaGdMMduefDVAg

This one gives a little more detail of the mechanical set-up. Surprising they are able to get that kind of acceleration from such a small vehicle.

On Tuesday, July 26, 2016 at 9:44:26 AM UTC-6, Bruce Hoult wrote:
On Wednesday, July 27, 2016 at 3:28:38 AM UTC+12, wrote:
On Tuesday, July 26, 2016 at 1:51:14 AM UTC-6, Peter Whitehead wrote:
On Tuesday, 26 July 2016 02:12:58 UTC+1, wrote:
Does anyone have particularly bad experiences with pulleys used like this. I am talking about the pulleys themselves. Has someone found a particular diameter that is too small. Obviously larger is better for both bearing speed and rope bending, but there are limitations on cost and availability...particular for the trial run I'm thinking about. I am considering a trial run with a swiveling pulley on the receiver hitch of a pickup, no guides, just the pulley, with around 8,000' of 1/4" poly hollow braid, flying a 1-26. That should prove the launch height, assuming the rope doesn't break on the first launch. I'm not sure what to expect at the pulley end, and don't want the rope jumping out of the sheave, catching and breaking. I doubt it will, but have no experience to back it up.

Hi, I wrote an article "The Expedition Pilot's guide to launching" in the Dec2013/Jan 2014 edition of the UK Sailplane and Gliding magazine. It may be of interest. I use 12mm diameter high density polypropylene rope (Skyrope from Skylaunch) on snatch blocks with, initally steel pulleys on plain bearings 110mm dia. The bearings cooked in spite of lots of grease! These have been modified for regular use to nylon pulleys with steel ball bearings. The steel flaps or cheeks of the snatch blocks keep the rope where it should be. I use either a 2 to 1 or 3 to one system to keep the tow speed down ( we use some rough fields). If you are serious then I can send you a copy of the article and details of the kit, as well as the links to YouTube videos of some launches in the Lake District (UK) using 2 to 1 pulley system, with one pulley on a ground anchor and the other on the car's tow hitch (with the rope tail to another ground anchor). Everything used is inexpensive, and it works. Pete Whitehead

Pete, I watched your videos, and those look like strong launches! Much better acceleration than we typically see. If you could send me an electronic copy of your article, I would love to read it.

Yes, the launches shown here look like normal launches from a pretty powerful winch, not the average rather anaemic direct-pull car launch. Sadly, we don't see anything of the vehicle or launch setup

https://www.youtube.com/channel/UC_G...WaGdMMduefDVAg

This one gives a little more detail of the mechanical set-up. Surprising they are able to get that kind of acceleration from such a small vehicle.

https://www.youtube.com/watch?v=Q0rv1zOmyWg

On Sunday, December 30, 2018 at 8:17:58 PM UTC-7, John Foster wrote:
On Tuesday, July 26, 2016 at 9:44:26 AM UTC-6, Bruce Hoult wrote:
On Wednesday, July 27, 2016 at 3:28:38 AM UTC+12, wrote:
On Tuesday, July 26, 2016 at 1:51:14 AM UTC-6, Peter Whitehead wrote:
On Tuesday, 26 July 2016 02:12:58 UTC+1, wrote:
Does anyone have particularly bad experiences with pulleys used like this. I am talking about the pulleys themselves. Has someone found a particular diameter that is too small. Obviously larger is better for both bearing speed and rope bending, but there are limitations on cost and availability...particular for the trial run I'm thinking about. I am considering a trial run with a swiveling pulley on the receiver hitch of a pickup, no guides, just the pulley, with around 8,000' of 1/4" poly hollow braid, flying a 1-26. That should prove the launch height, assuming the rope doesn't break on the first launch. I'm not sure what to expect at the pulley end, and don't want the rope jumping out of the sheave, catching and breaking. I doubt it will, but have no experience to back it up.

Hi, I wrote an article "The Expedition Pilot's guide to launching" in the Dec2013/Jan 2014 edition of the UK Sailplane and Gliding magazine. It may be of interest. I use 12mm diameter high density polypropylene rope (Skyrope from Skylaunch) on snatch blocks with, initally steel pulleys on plain bearings 110mm dia. The bearings cooked in spite of lots of grease! These have been modified for regular use to nylon pulleys with steel ball bearings. The steel flaps or cheeks of the snatch blocks keep the rope where it should be. I use either a 2 to 1 or 3 to one system to keep the tow speed down ( we use some rough fields). If you are serious then I can send you a copy of the article and details of the kit, as well as the links to YouTube videos of some launches in the Lake District (UK) using 2 to 1 pulley system, with one pulley on a ground anchor and the other on the car's tow hitch (with the rope tail to another ground anchor). Everything used is inexpensive, and it works. Pete Whitehead

Pete, I watched your videos, and those look like strong launches! Much better acceleration than we typically see. If you could send me an electronic copy of your article, I would love to read it.

Yes, the launches shown here look like normal launches from a pretty powerful winch, not the average rather anaemic direct-pull car launch. Sadly, we don't see anything of the vehicle or launch setup

https://www.youtube.com/channel/UC_G...WaGdMMduefDVAg

This one gives a little more detail of the mechanical set-up. Surprising they are able to get that kind of acceleration from such a small vehicle.

https://www.youtube.com/watch?v=Q0rv1zOmyWg

Anchored plus reverse pulley, so mechanical advantage of 2 plus speed reduction of 2, so the launch vehicle probably weighes 3,000lb or more so it can provide a 60mph rope speed at 30mph and not break traction on grass. Thus it can give a snappy launch. Slow turn around but better than just anchor pulley for short fields. Appears they can snap onto a working ridge nearby.

Frank Whiteley

On Sunday, December 30, 2018 at 8:17:58 PM UTC-7, John Foster wrote:
On Tuesday, July 26, 2016 at 9:44:26 AM UTC-6, Bruce Hoult wrote:
On Wednesday, July 27, 2016 at 3:28:38 AM UTC+12, wrote:
On Tuesday, July 26, 2016 at 1:51:14 AM UTC-6, Peter Whitehead wrote:
On Tuesday, 26 July 2016 02:12:58 UTC+1, wrote:
Does anyone have particularly bad experiences with pulleys used like this. I am talking about the pulleys themselves. Has someone found a particular diameter that is too small. Obviously larger is better for both bearing speed and rope bending, but there are limitations on cost and availability...particular for the trial run I'm thinking about. I am considering a trial run with a swiveling pulley on the receiver hitch of a pickup, no guides, just the pulley, with around 8,000' of 1/4" poly hollow braid, flying a 1-26. That should prove the launch height, assuming the rope doesn't break on the first launch. I'm not sure what to expect at the pulley end, and don't want the rope jumping out of the sheave, catching and breaking. I doubt it will, but have no experience to back it up.

Hi, I wrote an article "The Expedition Pilot's guide to launching" in the Dec2013/Jan 2014 edition of the UK Sailplane and Gliding magazine. It may be of interest. I use 12mm diameter high density polypropylene rope (Skyrope from Skylaunch) on snatch blocks with, initally steel pulleys on plain bearings 110mm dia. The bearings cooked in spite of lots of grease! These have been modified for regular use to nylon pulleys with steel ball bearings. The steel flaps or cheeks of the snatch blocks keep the rope where it should be. I use either a 2 to 1 or 3 to one system to keep the tow speed down ( we use some rough fields). If you are serious then I can send you a copy of the article and details of the kit, as well as the links to YouTube videos of some launches in the Lake District (UK) using 2 to 1 pulley system, with one pulley on a ground anchor and the other on the car's tow hitch (with the rope tail to another ground anchor). Everything used is inexpensive, and it works. Pete Whitehead

Pete, I watched your videos, and those look like strong launches! Much better acceleration than we typically see. If you could send me an electronic copy of your article, I would love to read it.

Yes, the launches shown here look like normal launches from a pretty powerful winch, not the average rather anaemic direct-pull car launch. Sadly, we don't see anything of the vehicle or launch setup

https://www.youtube.com/channel/UC_G...WaGdMMduefDVAg

This one gives a little more detail of the mechanical set-up. Surprising they are able to get that kind of acceleration from such a small vehicle.

https://www.youtube.com/watch?v=Q0rv1zOmyWg

It's a anchor/reverse pulley, thus different from the old Cotswold setup. 2x pull advantage and 2x rope acceleration, so a 2600-3000lb launch vehicle could provide adequate power and not break traction on turf using 4WD.

IMVHO,

Frank Whiteley

On 7/26/2016 9:28 AM, wrote:
Snip If you could send me an electronic copy of your article, I would love to read it.

Or post it on Dropbox or similar so we can all read it!
--
Dan, 5J