Ric
Well-known member
Figure of 8s and other devices don't work because it is too hard to control the friction - it is either all on or all off and nothing between. I spent a long time experimenting with them about ten years ago. The only boom-brake which works well is the Walder boom brake because the friction is spread over a large contact area with up to three wraps around the spiral-drum, so the friction can be controlled much more finely by the control line.