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.