Tunnel Boring Machine (TBM) 'Durga'
Why in News?
The Tunnel Boring Machine (TBM) 'Durga' is in the news because on July 10, 2026, it successfully achieved a major structural breakthrough at the under-construction Victoria Metro Station on Kolkata Metro's Purple Line.
Key Specifications of TBM 'Durga'
- Weight: Weighs approximately 600 to 650 tonnes.
- Length: Spans an impressive 90 to 95 metres in total operational length.
- Diameter: Features an outer boring diameter of 6.6 metres to assemble a finished 5.8-metre tunnel.
- Manufacturing: Built and assembled in Tamil Nadu, India (incorporating internal parts from Germany's Herrenknecht), highlighting the Make in India initiative.
- Machine Type: Uses Earth Pressure Balancing (EPB) technology to manage Kolkata's soft soil and high groundwater table safely.
Project Details & Next Phases
- The Route: Operating on the underground section of Kolkata Metro's Purple Line, which aims to connect Joka to Esplanade.
- Executing Agency: The project is being managed and driven by Rail Vikas Nigam Limited (RVNL) along with L&T.
- The Companion Borer: A sibling TBM named 'Divya' is currently burrowing the parallel twin tunnel and is expected to hit its Victoria breakthrough soon.
- Next Destination: 'Durga' will be retrieved, structural adjustments will be completed, and it will be relaunched from Victoria station to bore another 900 metres toward Park Street.
- Overall Goal: The ultimate project timeline aims for full corridor completion by December 2029.
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