Metro services on the Blue Line or the north-south corridor were disrupted for close to two hours on Tuesday morning after a train was stranded between Netaji Bhavan and Rabindra Sadan following a technical glitch.

The day’s first train, which left Tollygunge for Dakshineswar around 6.55am, was stuck in the tunnel just after it went past Netaji Bhavan around 7.15am. A Metro official blamed an “electric power supply issue”.

The problem was traced to a third rail current collector, an equipment attached to the undercarriage of the train that collects power from the third rail of a Metro track. Each compartment in a rake typically has four such current collectors on either side.

“The driver sensed something was amiss and stopped the train for safety reasons. It was later reversed to Netaji Bhavan station, where passengers were requested to get off. The train was later taken to the Y-siding at Maidan station (a provision where a train can switch tracks). It will be taken to the car shed for a detailed inspection after the end of commercial services,” said the Metro spokesperson.

“Trains did not run between Maidan and Tollygunge (Mahanayak Uttam Kumar) till 8.45am. Truncated services were run between Dakshineswar and Maidan in the north and between Mahanayak Uttam Kumar and Shahid Khudiram in the south. Full services on the entire stretch resumed at 8.46am,” the spokesperson said.

The disruption started early in the morning and continued into the peak office rush. Thousands of commuters had to struggle to find alternate modes of transport.

Tuesday’s disruption was the latest on the ageing and snag-prone Blue Line, already grappling with operational constraints after commercial operations were suspended at Kavi Subhash (New Garia) on July 28 last year following cracks in the platform pillars.

A series of suicides and suicide bids has amplified the problem.