
August 2026 · Nuwakot, Nepal
Into the Upper Trishuli-1 tunnel
- Problem
- After the August 2026 flood, rescuers needed eyes inside a flooded, debris-filled hydropower tunnel where radio video signals die at the first bend.
- Built
- Overnight, a relay that converts 5.8 GHz video to 1.2 GHz so the signal bends through wet concrete. Army special forces carried it in on a trekking stick.
- Result
- The drone reached the first debris platform before rockfall closed the way. The Nepal Army's follow-up mission confirmed what it showed.
- to design and build the relay
- 1 night
- tunnel length
- ~180 m
- relay frequency
- 1.2 GHz



