Kolkata Purple Line Clears Another Key Tunnel Hurdle
Kolkata’s Purple Line has moved another step towards completing its underground section, with tunnel boring machine (TBM) Divya reaching the Victoria station site after excavating the second tunnel from Kidderpore. The development strengthens the Joka–Esplanade corridor’s prospects of improving access between the city’s southwestern suburbs and central Kolkata, while keeping attention on the remaining construction and integration work.
The latest breakthrough follows the completion of the parallel tunnel by TBM Durga in July. Together, the two machines are constructing the twin-tube underground section between Kidderpore and Park Street. Divya’s work began from the Kidderpore launching shaft in October 2025, following Durga’s deployment in July that year.The underground drive has required specialised equipment because Kolkata’s subsurface conditions include soft soil and a high groundwater table. The machines use Earth Pressure Balance technology, which helps maintain pressure at the cutting face while excavation takes place. This is particularly important beneath densely developed areas, where uncontrolled ground movement could affect roads, buildings and other surface infrastructure.
For residents, however, the significance of the Purple Line extends beyond the engineering achievement. The corridor is intended to connect Joka and the southwestern part of Kolkata with the central city, creating a stronger public transport alternative to road-based travel. The operational network currently covers the elevated Joka–Majerhat section, while the remaining alignment is being built towards Esplanade.The project’s history also illustrates why construction milestones need to be viewed alongside delivery timelines. The Purple Line was conceived years ago but faced land availability and other implementation constraints, resulting in work progressing in stages. The latest Kolkata Purple Line milestone therefore represents progress on a long-delayed urban transport investment, rather than the completion of the corridor itself.The wider urban benefit will ultimately depend on how effectively the new infrastructure connects with existing metro services, buses, walking routes and neighbourhood streets. Faster rail access can reduce dependence on private vehicles, but the climate and mobility gains will be strongest when stations are safe, accessible and well integrated with everyday journeys.
Attention now shifts to the remaining underground works, station construction and systems integration before passenger services can begin across the completed sections. For Kolkata, the Kolkata Purple Line is increasingly becoming a test of whether major infrastructure can translate construction progress into reliable, accessible and lower-carbon urban mobility.
