Kolkata19 minutes agoAuthor: Tirthankar Das
The Kolkata Metro Purple Line extension has reached a significant milestone with the tunnel boring machine (TBM) ‘Divya’ breaking through the underground concrete wall at the Victoria Memorial Metro station.
Divya reaches Victoria Memorial underground station
The massive machine began its journey in October last year from the area in front of St Thomas School in Kidderpore. After working continuously for nearly 10 months, Divya has completed a 2.65-kilometre-long tunnel from Kidderpore to Victoria Memorial, reaching its destination.
Twin TBMs advance Purple Line construction
Two specialised TBMs, named ‘Durga’ and ‘Divya’, were deployed for the construction of the twin tunnels. Last month, Durga completed one of the tunnels and reached the underground Victoria station. Divya has now followed the same route and completed the second tunnel.
The successful completion of the twin tunnels has strengthened hopes of launching commercial metro services across the Joka–Esplanade Purple Line by Diwali 2029.
Complex tunnelling crosses challenging underground stretches
The tunnelling work involved challenging stretches beneath the Adi Ganga, as well as areas near the Victoria Memorial and major high-rise structures including Tata Centre and Everest House.
Given the complexity of the underground construction, authorities will maintain strict monitoring for the next two months. Engineers will examine the area for any possible impact, including ground settlement or other changes caused by the construction of the up- and down-line tunnels.
Next tunnelling phase begins after break
If everything proceeds as planned, work on the next phase will begin after a break of around two and a half months.
Durga and Divya will then undertake the next tunnelling operation from Victoria to Park Street, involving twin tunnels stretching approximately 914 metres beneath the Brigade Parade Ground.
Durga expected to reach Park Street
Durga is expected to reach Park Street station by December 2026, while Divya is likely to complete the journey by March 2027. Once the tunnels up to Park Street are completed, the construction method will change. The remaining underground work will be carried out using the ‘cut-and-cover’ technique.
