Signalling blues: Trains crawl for hours on metro's Line 3

Signalling glitch crippled services on Delhi Metro's Blue Line for several hours this morning, inconveniencing commuters as trains crawled and halted for long durations along the corridor.
Trains were run on restricted speed of 20-25 km per hour on the affected stretch near the Dwarka station.
The ripple effect brought the entire line on its knees, especially the trains leading towards Dwarka, frustrating rush-hour commuters.
"Around 11.50 AM, which is an off-peak hour, a 10-minute window was created to rectify the track circuit drop (signalling issue) during which train movement was regulated.
"The problem was rectified around 12 and gradually normal services were restored. Although bunching effect led to some more delay," a metro official said.

The two branches of Blue Line (Line 3/4), that have gained considerable infamy due to frequent snags, connect Dwarka Sector 21 to Noida City Centre and Vaishali.

Dwarka station is also used for reversal of trains therefore to avoid any major impact on services, trains were temporarily reversed from Dwakra Sector 12 station instead.
"A few trains were also short looped from Rajouri Garden and Janakpuri West Metro stations towards Noida/Vaishali side providing regular services with slight decrease in frequency of trains during the period," the official said.
Only last month, DMRC had apologised to people after a major glitch led to trains losing contact with the Operational Control Centre (OCC) for two successive days, triggering long delays and outrage.

Metro authorities say the issues on the corridor like track circuit failure or snags in overhead wiring have much to do with its exposure to nature and as most of it is overground and gets affected by temperature fluctuations.
With around five interchange stations along its length, Blue Line is currently metro's busiest corridor. It carries around 30 per cent of its total passenger volume or around 12 lakh commuters on a daily basis.