In a landmark moment for urban mobility, the 90‑metre‑long, 650‑tonne Tunnel Boring Machine Durga pierced the final barrier at Victoria station around 10:30 a.m., eliciting chants of “Vande Mataram” from engineers on site. This achievement finalises the first phase of underground tunnelling on the up‑line facing Park Street, a critical step for the Joka‑to‑Esplanade Purple Line.

Project Background

The Purple Line, conceived in 2009, has wrestled with land‑acquisition bottlenecks, fragmented construction schedules, and historic subsidence incidents in the Bowbazar area. Despite these setbacks, the Kolkata Metro Authority has persisted, targeting a 14 km corridor that will blend elevated and underground sections to connect Joka with the city centre at Esplanade.

Technical Details and Durga’s Journey

Durga commenced its subterranean trek on July 10, 2025, from Kidderpore, boring 17 metres below ground near St Thomas’ Boys School. Over the ensuing 365 days the machine excavated a flawless 1.7 km tunnel, navigating sensitive zones such as Fort William and the PTS station without surface disturbance. Built with core components from Germany’s Herrenknecht and assembled in Tamil Nadu, Durga exemplifies a proud ‘Make‑in‑India’ engineering effort.

Future Plans and Impact

With the 1.7 km stretch now complete, Durga will be redeployed from Victoria station to tunnel the remaining 900 metres toward Park Street, culminating in a 2.65 km twin‑tube system. Completion will deliver faster, less‑crowded, and greener transit options, reducing Kolkata’s carbon footprint while showcasing indigenous large‑scale infrastructure capabilities. The parallel TBM ‘Divya’, currently advancing the down‑line Jokamukhi section, is slated to meet its August 2026 deadline, reinforcing the city’s ambitious timetable.