TBM Durga achieves major tunnel breakthrough at Victoria for Kolkata Metro Purple Line Expansion

Kolkata, India (Metro Rail Today): The Metro Railway Kolkata and Rail Vikas Nigam Limited (RVNL) have achieved a major engineering milestone with the successful breakthrough of Tunnel Boring Machine (TBM) 'Durga' at Victoria Metro Station, marking the completion of a crucial underground tunnel section between Khidderpore and Victoria on the Joka–Esplanade (Purple Line) Metro Corridor.

The breakthrough, achieved after the tunnelling drive commenced on 10 July 2025, represents a significant step towards the completion of one of Kolkata's most strategically important metro expansion projects. The achievement further strengthens the city's growing rapid transit network while demonstrating India's capability in executing complex underground infrastructure beneath densely populated urban environments.

Major Underground Tunnelling Milestone

The successful breakthrough completes one of the key underground tunnel drives on the Purple Line, which will eventually connect Joka in South Kolkata with Esplanade, providing a high-capacity public transport link between the city's southern suburbs and its central business district.

The tunnelling operation was carried out using advanced Tunnel Boring Machine technology while maintaining stringent standards of safety, quality and environmental protection. Despite the engineering complexities associated with constructing underground infrastructure beneath one of India's oldest metropolitan cities, the project was executed with minimal disruption to surface traffic and surrounding urban activities.

As the executing agency for the project, Rail Vikas Nigam Limited (RVNL) has been entrusted with delivering world-class underground metro infrastructure under challenging geological and urban conditions. The breakthrough reflects meticulous planning, engineering excellence and close coordination among project stakeholders.

Strengthening Kolkata's Metro Network

The Joka–Esplanade Metro Corridor is expected to significantly improve east-west connectivity across Kolkata by linking the city's rapidly developing southern neighbourhoods with important commercial, administrative and institutional centres. Once operational, the corridor will reduce travel time, ease road congestion and encourage greater use of environmentally sustainable public transport.

The breakthrough of TBM 'Durga' is another important achievement in Kolkata Metro's ongoing expansion programme. In recent weeks, the metro network has recorded a series of significant milestones, including the successful completion of the critical 62-metre viaduct gap at Chingrighata on the Kavi Subhash–Airport (Orange Line) corridor. The completion of this long-pending viaduct removed a major construction bottleneck and accelerated progress towards connecting Netaji Subhas Chandra Bose International Airport with the city's metro network.

During his recent visit to Kolkata, Union Minister for Railways Ashwini Vaishnaw reviewed the progress of various metro expansion projects. He travelled on the metro from Jai Hind Bimanbandar to Noapara station, interacted with passengers to understand their travel experience and later inspected the Chingrighata construction site. The Minister also announced that approximately 60 new-generation metro trains will be inducted over the next four to five years and highlighted that nearly 45 kilometres of new metro network have been commissioned in and around Kolkata since 2014.

"The successful breakthrough of TBM 'Durga' is another testament to India's growing expertise in delivering technologically advanced underground metro infrastructure. Complex tunnelling projects beneath dense urban environments require exceptional engineering precision, rigorous safety standards and seamless collaboration among all stakeholders. Such milestones not only accelerate project delivery but also reinforce the country's commitment to developing sustainable, world-class urban mobility systems that support economic growth and improve the quality of life for millions of citizens," said Mrs. Mamta Shah, MD & CEO of Urban Infra Group.

RVNL Driving Major Metro Infrastructure Development

RVNL is currently executing three flagship Kolkata Metro corridors with a combined length of approximately 60.5 kilometres and a sanctioned project portfolio valued at around ₹23,818 crore. These projects form a critical part of the city's long-term transportation strategy, aimed at expanding metro connectivity, reducing dependence on road-based transport and supporting sustainable urban development.

The successful completion of the Khidderpore–Victoria tunnel represents another important milestone towards the delivery of the Joka–Esplanade Metro Corridor. As construction progresses across multiple corridors, Kolkata Metro continues to strengthen its position as one of India's fastest-growing urban rail networks, contributing to the broader vision of Viksit Bharat through modern, efficient and environmentally responsible public transport infrastructure.