New Delhi, In anticipation of the fog towards the end of November and early December, the railways has sent advisories to all the zones to keep safety on the top priority this season. As visibility reduces by several meters during thick fog, trains run at a lower speed.
A vision test object (VTO) would be set up at the station to indicate fog. This VTO would be installed at least 180 meters from the starter signal of the station. And if the station superintendent fails to see the VTO clearly from the station, fog warning would be issued and advisories will be put in place immediately. A VTO can be fixed at any station.
During normal weather conditions, drivers can see a signal clearly at a distance of 300 meters but when fog persists, the visibility reduces manifold, some times dropping to 10 to 20 meters. Since a driver cannot see a signal from a normal distance, the speed of trains has to be reduced from normal 100 kmph to 60 kmph. While the speed cannot exceed 60 kmph limit in such situations, it may be reduced to as low as 15 kmph for safety purposes, depending on the density of fog.
Despite fog severely affecting movement of trains every winter in Northern India, railways still lack technology to reduce its impact. Trains passing through stations along the rivers and hilly areas are the worst hit by fog. It is regular for some trains to run almost 24 hours behind schedule during winter.
Foggy conditions are expected in early December as by then the Western Disturbance persisting over Jammu & Kashmir will move away from the region, letting the cooler winds enter northern India. These winds would drop the minimum temperatures significantly to create foggy conditions during the first week of this December.
