On Tuesday, July 19, 2016 at 10:25:55 AM UTC-6, Steve Leonard wrote:
On Tuesday, July 19, 2016 at 10:22:07 AM UTC-5, wrote:

I'm not sure I see much advantage of a 2:1 system (assuming you mean the reverse-driving vehicle has a pulley as well). Wouldn't you still be dragging 4,000 ft of rope behind the tow vehicle (from the fixed pulley)? It hardly seems worth the extra rigging trouble...but I've never done it either.. My primary concern is rope wear, and I'm not seeing much improvement with that. Please let me know what I am missing.

Stephen

End of rope is anchored to the ground. Rope goes around pulley on the launch car, then back to the glider. Car travels half the speed of the glider (2:1 system). The only rope moving relative to the ground during the launch is the rope between the pulley and the glider. And similar to a winch launch, all that rope becomes airborne pretty quickly.

Steve Leonard

That will probably give the most rope life for UHMWPE or dacron ropes.

http://linearcomposites.net/media/pa...e_study_13.pdf
Used 500m lengths of this for autotow and got 1500ft launches with L-13 and G-103. Doesn't like pulleys I'm told. Another poster said they had frequent breaks. Wasn't my experience. Rather heavy.

Frank Whiteley