Fogged out: How Railways and airlines tackle fog-induced disruptions in winter, Pg19

Key Highlights:

• Indian Railways and airlines face disruptions every winter due to fog, particularly in northern India.
• Radiation fog, formed under clear winter nights, reduces visibility, impacting both air and rail transport.
• Airports use Low Visibility Procedures (LVPs), including Low Visibility Take-Off (LVTO) and Instrument Landing System (ILS) CAT IIIB landings.
• Indian Railways uses Fog Safety Devices (FSD) and the Automatic Train Protection (ATP) system called Kavach to mitigate fog-induced delays.

Detailed Insights:

• Radiation fog is exacerbated by high pollution levels, compounding disruptions for airlines.
• LVPs increase the time between landings and take-offs, leading to congestion and delays.
• Airlines divert flights to fair-weather alternative airports with engineering staff stationed for real-time weather assessment.
• Flight Duty Time Limitation (FDTL) guidelines require pilots exceeding duty time to be taken off duty, further complicating operations.
• FSDs are GPS-based systems alerting train drivers to upcoming signals and crossings within a geo-fenced range.
• Kavach ensures trains maintain speed during dense fog by displaying relevant information on a dashboard and automatically applying brakes if needed.
• The Railways have introduced luminous strips on signalling equipment to improve visibility during foggy conditions.

Key Concepts Involved:

• Radiation Fog: Fog formed by the cooling of land after sunset, radiating its heat into the air.
• ILS CAT IIIB: A high-precision landing system allowing aircraft landings with visibility as low as 50 meters.
• Automatic Train Protection (ATP): A system that automatically controls train speed and braking to prevent accidents.