I do bivouac paragliding flights (vol-biv). That’s when you fly fully self-supported (tent, sleeping bag, cooking kit, etc. — except water) for 3–7 days. I haven’t gone longer yet. You land on sites suitable for launching the next day, usually on summits. Every year I try to do such bivouacs, gradually increasing the difficulty. The last one ended two weeks ago: I flew 365 km across the Himalayas. I was almost brushing 6,000-meter peaks with my wing, but for overnight stops I descended to around 4,000 m, because pitching a tent and sleeping on snow is far less comfortable than on grass. With suitable weather the next day, I can regain that altitude in 20–40 minutes. And once the camp is set, you can take light day trips around the area — which I really enjoy. I have great respect for people who hike into the mountains on foot, but I’m too lazy for that myself and prefer to use natural forces to get up high.
The possibility of ending up in a difficult situation — hanging in a tree — is very real. And trees in the Himalayas are tall. That’s why an ultra-light descent device is needed. I have a strict weight limit for flying and can’t exceed it, and in autonomous mountain flights you have to carry a lot of essential gear. That’s why a 3 mm cord is required.
We are talking about an emergency, one-time descent as the only way to save a life. The alternative, of course, is waiting up to a week for rescuers.
I can’t use the carabiners from my paraglider harness, because I have to descend while wearing it. It effectively is my climbing harness, and it also holds all the gear I need to make my way back to civilization.
Yes, branches are a hazard — you have to be careful.
Now imagine this: you’re hanging in your harness, usually twisted sideways. You can’t reach the trunk, and if you do, it’s often too thick to wrap your arms around. All nearby branches are thin. Below you there’s about 15 meters of height and a slope at roughly 45 degrees. And there’s no room for a standard diameter climbing rope.
The descender is attached to the harness I’m hanging in. We assume the worst-case scenario, where you can’t reach a single solid branch. The paraglider riser-lines are tied at the top in a way that keeps the load evenly distributed and prevents them from sliding off the canopy. For this I use a self-tightening knot normally used to tie fishing hooks to line. Then, using three meters of additional 6 mm accessory cord, I transfer the load from the wing’s risers onto a loop made from this cord. I re-clip the carabiners, then arm the descender and slowly lower myself, seated in my harness.
I use this device (the KONG "Kisa" energy absorber, 65 g — ed. note), only with the Dyneema threaded slightly differently. That gives roughly 15 bends, resulting in a manageable level of friction during the descent"