On Tuesday, May 21, 2013 8:10:22 AM UTC-6, WB wrote:
In article ,

Chris Nicholas wrote:



It is possible and highly desirable to fit a guillotine to a pulley system.

My club had considerable experience with reverse pulley for many years when

we had a hard runway, and developed it to a great degree.



Method: We had 2 pulley wheels in a frame which pivoted about a horizontal

axis, and also mounted so that it could swing sideways. This enabled the

cable to run true from glider to one pulley, and from the other pulley to the

tow vehicle. Both pulleys were framed in lead-in guards. The horizontal pivot

was hollow. A spring loaded chisel-edged cutter ran through it. This could be

released from the cab of the truck on which the pulley system was mounted. It

would hit the cable, against an anvil mounted between the two pulleys. It

worked.





Sounds like an excellent setup. If we ever do groundlaunch again, we

will have to put together a guillotine system like that. Your guillotine

sounds almost identical to the one Glen Lawler put on the Eagle Winch.

It was a spring loaded chisel firing against an anvil. A hydraulic jack

was used to cock the thing. Made a heck of bang when fired. It would

shear steel rope like it was made of air. Not sure how well it worked on

Spectra, but I would expect that it had no trouble with it, especially

with any tension on the line.

http://www.coloradosoaring.org/think...ey/default.htm

No guillotine, wire and tackle pulled through the 'pulley' apparently.