A round-trip patrol of the 6-kilometer section most prone to accumulating ice takes three to four hours. Patrol routes wind through steep cliffs and deep valleys. The roads grow slippery after winter storms, forcing workers to spread road salt or shovel snow to clear paths. Drones often fail in low temperatures, forcing manual inspections. Only 2-3 staff rotate during the 3-4 month ice melting season, monitoring more than 600 kilometers of lines and staying on standby even during festivals.