So, I bought 50 meters of rope to help the kids get to the top of this huge cliff face at an abandoned quarry.
Once the fun wore off I decided to tie the other end to a tree trunk at the bottom of the big hill... and tried to zip wire down.
The first attempt failed. Too much friction! So I removed my underwear and placed it between the rope handles and the rope line. It worked like a charm!
My only problem was that half way down I bottled out. When I let go, the zip wire flew upwards with the release of tension and my underpants were flung high into the air.
I believe they landed in a bush somewhere.
Toasted marshmallows made everything ok in the end.