inaugurating the Noapara-Dakshineswar stretch of Blue Line on February 22, 2021. The laying of the founding stone was done in 1972, but actual construction of Blue Line started only in 1978. Blue Line is long with 26 stations (see above). Running of the first metro car on the line by 1984 was considered a great engineering challenge. Former railways minister
A. B. A. Ghani Khan Chowdhury took a massive effort to perform it. The first section opened between
Esplanade &
Bhawanipore (now called Netaji Bhawan). First day Metro Railway Kolkata was started by Sri Tapan Kumar Nath and Sri Sanjay Sil. There were no connections of this stretch with the two depots at
Dum Dum &
Tollygunge (Now called Mahanayak Uttam Kumar). So metro cars had to be put down on the track near Esplanade by crane, by directly digging the road surface. Initially, only four-car trains were run until 1986. There were no magnetic gates or escalators at that time and ordinary revolving gates served as exits. The Metro too operated on only a single line. Two years later, Blue Line extended up to Tollygunge, at the southern end. At the same time, the metro service was extended to the double line. Magnetic tickets and more entry gates were also introduced at that time. The number of compartments in each train was increased to eight. Metro service was also started from
Dum Dum, at the northern end, to
Belgachia in parallel with the extension of the line to the south. But this short portion was not popular and the service was closed down to be restarted when the entire stretch along the north–south corridor was completed. After 1986 many political incidents hampered the construction, and work almost stopped for nearly six years. After restarting work, the
Dum Dum to
Shyambazar metro service was started in 1994. This portion was served by four-car trains. Two months later, the Esplanade –
Chandni Chowk section was opened and Chandni Chowk –
Central section opened three months later. The service from Dum Dum to Tollygunge started in 1995, with
Mahatma Gandhi Road metro station, opening in 1996. During this time, more magnetic gates and escalators were added and the revolving gates were slowly phased out. In 2009, a large number of stations on Blue Line were renamed by then Minister of Railways
Mamata Banerjee. On 22 February 2021, the Noapara – Dakshineswar stretch was inaugurated by
Prime Minister Narendra Modi. On 21 July 2024, the entire stretch from Dakshineswar to Kavi Subhash, crossed 1.92 lakh passenger mark for the first time on a single day. On 28 July 2025, cracks were detected in the last four columns of the Line-1 Up platform at
Kavi Subhash station, the line's southern terminus. So, the Line-1 platforms of the station were closed to passengers as a safety measure and the trains are being terminated at
Shahid Khudiram station. However, the empty rakes would continue to run up to the station for reversal and maintenance at its depot.On investigation, it was found that the damage on the columns supporting the platforms were weakened beyond repair. So, Metro Authorities decided to raze the entire Line-1 complex of the station (keeping the tracks intact) and rebuild it. E-tenders were floated and the work is expected to be completed within ten months. == Timeline ==