Tow line and loops?

[LRFitch]

Guys, I'm working on a larger glider this winter. Can any of the "big scale fliers" share what you use for 8+ meter gliders that likely weigh 40+ pounds use for tow lines and tow loops?

Thanks,
Larry

[Xroadie]

The standard tow ropes these days are paracord. They will handle the heaviest of gliders. As far as loops go, I am old school and on all my gliders I use loops that act as a weak link. I use 80lb loops on my 1/2 scale Ka6, which weighs 50lbs. and have even gotten away with 50lb. loops when I was out of the 80lb stuff. Many people don't believe in weak links but I do and have always used them, even on the towplane end of my tow ropes. BTW....I am not a fan of loops made of mason line...or whatever the material is that is very popular, it is very flimsy/flexible and easily tangles in the snap/swivel after release. I use braided dacron fishing leader line that is waxy and stiff....it does not tangle as easy and is also easier to feed into my tow releases. Something else I like about the braided dacron leader line is that each weight is a different color making it easier to tell which weight loop I am grabbing for whichever model I am flying.

[LRFitch]

Xroadie, Thanks for the response. I'll buy some of your recommended loop material this afternoon at my local tackle shop. I know nothing about paracord. In a quick look on the web I see several sizes, but the most popular size for making bracelets is 550 size? Do you know what size guys are using for tow lines? I take it most use 120 foot long tow lines?

Thanks,
Larry

[Steve P]

550 is more visible on tow helping both pilots have a good read on how things are going. Neon yellow is most popular color followed by Neon orange. Paracord has become the clear choice, although some tow plane side releases are tight, needing a loop on that end as well to insert into the release. Paracord 220 is an ideal size and more than strong enough, but lacks the very good visibility of its bigger brother. There are a number of good vendors, I deal with Paracord Planet, but you really just want the best combo of price plus shipping. 100 foot hanks.

[Tango Juliet]

I don't recall offhand the strength, but the inner cords of the 550 cord can be pulled out of the outer (colored) sheath. Perhaps as individual strands they can be used for your weak-link loops. 550 cord gets its strength from all of the strands inside the sheath.

[Asher Carmichael]

Everything said above pretty well covers it. I'm really old school in that I use a dacron/ripstop nylon flag 15'-20' ahead of the sailplane end. Most people don't bother but I find it helpful.
Here's some info on towlines from my blog for what it's worth.

https://www.rcgroups.com/forums/show...4&d=1408027318

[JimD]

FWIW, I discovered this source for paracord in a slightly smaller diameter (425 vs 550) and it has worked very well. It readily fits into the TopModel tow release mechanism, comes packaged in 100' lengths, and the neon yellow is easy to see.

https://paracord.com/collections/425-cord-solids/products/425-neon-yellow

[LRFitch]

Asher, Jim,
Thanks for the useful info and sketch. I think I'll buy a couple lengths of the 425. I've got the loop material now as well as the swivel clips for the glider end, and should now be ready before Spring. Now need to get more done on the Nimbus, so I have something big to tow. Here in the PNW, flags are still used Asher. I guess we are rather "old school" too. I guess a trip to the fabric shop is on the list as well.

Thanks Again,
Larry

[JackA]

Hey guys,
I want to make some tow loops and I thought at one time there was an illustration somewhere on the site that showed how to make them however I do not see that now. Can someone please instruct me on how to make them. Or if it is still on the site please direct me on where to find it. I may be just overlooking it.

Jack

[lenb]

Jack,
It's pretty low tech. Use some line that will fit in the tow release, about 10" piece or so and just knot it into a loop.

[JackA]

Thanks Len, I didn't know if it needed to be a certain size or type of cord but sounds like I was trying to be to technical about it.

[lenb]

The tow look is the weak link between the tow line and the glider.
The bigger the plane the more tow loop size you want.

There is some info in this thread too

http://forum.scalesoaring.com/forum/aerotowing-slope-scale-soaring/beginner-s-forum/20459-tow-line-and-loops

[Tango Juliet]

In this photo of loops on a standard traffic cone, you can see the various size loops and thickness of cords used depending on the size/weight of the sailplane being towed. For some it's also a personal choice. Some want a stronger loop, while others want it weaker.

[LRFitch]

I got my recently purchased, slightly used Hempel KA-6 in the air yesterday--three successful flights. However, on two tows we had equipment failures. On the first flight the tow loop failed at about 150', and on second flight the tow line failed along it's length ( old line I think) at about 200'. Neither break caused a huge problem for the glider, but it showed that towing 25-30 pound gliders isn't the same as towing a 46# glider. A few lessons learned. Likely the most important lesson was not about upgrading tow line equipment, but having a really good pilot standing next to you on these first flights (likely all flights until I'm really comfortable with this new-to-me glider). Thanks Don Bailey! Also thanks to Ivan "the Terrible" and his wonderful TONKA tug.
Check your equipment and make sure it's up to the task at hand. These were the first tow-line type failures I've ever seen, so it caught me off guard. I've seen several loops come out of the glider release because it wasn't inserted quite right, not never a "break".