Disruptions have become synonymous with Metro Railway, once considered the city’s most reliable mode of public transport.
On Wednesday, a technical glitch in the signalling system brought the East-West Metro corridor (Green Line) to a halt for over two hours. The Blue Line (North-South corridor) — Calcutta’s oldest Metro route — has been suffering repeated delays since July 28, following the suspension of commercial services at Kavi Subhash (New Garia) station. The shutdown was triggered by cracks detected in the platform pillars at the southern terminal.
This newspaper spoke to multiple Metro officials and engineers to understand what’s behind the recurring breakdowns.
Green Line
Wednesday’s snag disrupted services across the entire 16.6km East-West corridor between Sector V and Howrah Maidan. Operations were suspended from 10.35am to 11.46am, with partial resumption between Sealdah and Sector V at 11.46am. Full services were restored by 1.01pm, a Metro official said.
The East-West Metro operates on a Communication-Based Train Control (CBTC) system. Before the Sealdah-Esplanade stretch was commissioned on August 22, the corridor ran in two phases — Howrah Maidan to Esplanade and Sealdah to Sector V — each with separate CBTC systems. Prior to full launch, these were merged into a single integrated system.
“This integration means that a fault in any section affects the entire system. That’s what happened on Wednesday,” said a Metro official.
Sources said Metro personnel were unable to resolve the issue and experts from the signalling and telecommunication company had to be called in. A maintenance contract with the company is yet to be renewed, sources said. “Our staff need more training to be fully familiar with the new system,” said one of them.
Service resumed only after an alternate backup mode was implemented. “The exact cause of the problem will be confirmed at night after commercial operations end,” the source said.
The snag, the Green Line’s most serious disruption so far, raised concerns about its reliability.
The problem was reported around 10.30am. Metro officials had two options: switch to manual mode or suspend operations. “We didn’t have enough personnel for manual operations, so we had to suspend service entirely,” said a source.
Manual operations would have required slower train movement and manual synchronisation of train doors with platform screen doors.
The breakdown led to chaos for many passengers, especially with limited alternative transport available due to Vishwakarma Puja. Some passengers began protesting at Howrah Maidan station, alleging that their smart cards had been “locked” and fares deducted despite no train service. A Metro official later said that refunds were issued.
Blue Line
The root of the Blue Line’s troubles lies in the suspension of services at New Garia, Metro officials said.
With the southern terminal out of operation, trains now require more time to reverse, causing a cascading effect: delays, overcrowding, and disrupted schedules throughout the corridor. The New Garia car shed has also been cut off, making operations harder to manage.
Currently, it takes at least eight minutes for a train to switch tracks between New Garia and Shahid Khudiram, up from the usual five. At the Dakshineswar terminal in the north, trains were earlier required to pause for two extra minutes due to space constraints. Following infrastructural upgrades and Railway Board clearance in late July, this delay has now been resolved.
“Had New Garia been functional, turnaround time at both ends could have been synchronised, allowing better frequency. Instead, we are struggling to maintain the existing schedule,” said an official.
Repairs at New Garia are scheduled to begin after Durga Puja and may take around a year. In the meantime, Metro authorities are working on interim fixes.
A new rake reversal point is being constructed at Shahid Khudiram (Briji) station, the new southern terminal. Additionally, the old carshed atMahanayak Uttam Kumar (Tollygunge) — the former southern terminal — has been revived.
“The new reversal point will be ready after Durga Puja. The Tollygunge shed can now accommodate eight rakes, and two more can be kept on the platforms,” said a Metro official. “In case of emergencies, like a train getting stranded between Tollygunge and Shahid Khudiram, a fresh rake can be sent from the shed to maintain service.”