What's ailing Blue Line? Metro apologises, shares details

Trains on Delhi Metro's Blue Line came to an abrupt halt for the second straight day today after losing contact with the Operational Control Centre (OCC), the nerve centre of the vast network, due to power failure, triggering long delays and public outrage.
This prompted DMRC to issue an apology to the commuters through a video statement posted on its website. Metro attributed the delay to its cautious approach, saying it did not want to "compromise" the safety of the passengers.
Sharing details, Chief Spokesperson of DMRC Anuj Dayal, said that around 5.14 PM yesterday and 11.28 AM today, the control of the signalling and Automatic Train Control system of Blue Line was lost at the OCC level due to power failure.

"The screen went black in OCC. It may seem akin to an aircraft going off the ATC radar but is not as dangerous as the local control centres, numbering around 17 on this line, took over as alternative. But it certainly led to delays as things became manual," Dayal said.
He also apologised to the commuters and thanked them for maintaining "discipline" despite hardship. "Trains appeared to crawl as their speeds were deliberately reduced keeping safety in mind," he said.
As power snapped, centralised operation of trains were not possible during the period as "train IDs" (used to identify individual trains) were lost, so the 17 "interlocking" stations of line 3/4 (Dwarka Sector 21-Noida City Centre/Vaishali) were told to operate trains at local level.

At interlocking stations, trains can change tracks and have reversal facility and station controllers are authorised to manage trains manually.
A senior official at the OCC explained that although power was restored within four minutes, OCC gained control of operations at 11.43 AM and the entire process was completed only by 12.20 PM.
But it took time for trains halted across the corridor to resume services and commuters were forced to withstand overcrowded coaches and platforms.