Winching - Reverse Auto Tow

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

Thanks Steve. I was thinking about the rope being fixed at the end of the runway opposite the glider, going around a pulley on the tow vehicle, then back to a pulley next to the fixed end (again...opposite the glider). I was thinking that the only advantage was mechanical (1/2 speed). Now it's clear to me.