The time of the year dreaded by air travellers is here. If Friday night and Saturday morning were any indication, the fog is ready to keep its date with Delhi. Although flight schedules have not been hit yet, the meteorological department says visibility is worsening each day and dense fog can be expected anytime now.
R.K. Jenamani, director, Indian Meteorological Department (IGI unit), said: “Moderate fog set in over the Indira Gandhi International (IGI) airport on Friday night and between 8 a.m. to 10 a.m. on Saturday. Visibility went down to 500 metres.” He said it was time to monitor the fog and the airport should be prepared for dense fog.
“Visibility has started worsening. It is approaching the critical range after which the CAT III B Instrument Landing System (ILS) - the most sophisticated available - will have to be put into operation.”
On the tracks, too
The railways is also gearing for foggy conditions. To prevent accidents, the railways relies on a system of manual inspection by “fogmen” to ascertain visibility.
“The station master takes stock of the visibility and instructs fogmen to install tiny explosive discs -- detonators -- on the tracks, ahead of the signals,” said Northern Railways spokesman Rajiv Saxena. “The detonators emit small, bursting sounds when a train run over them and the driver gets an audio signal. Depending on the number of detonators, the driver understands the nature of the signal ahead.”