In a significant move to overhaul the transit landscape of the city of Kolkata, the Joka-BBD Bagh (Purple Line) Metro project is entering a pivotal new phase. With the initial stretch to Majerhat already operational, focus has shifted toward the critical link connecting the premier Indian Institute of Management (IIM) Calcutta directly to the city’s central business district.
Once completed, the 15.08 km corridor will allow residents of Joka and Thakurpukur to bypass the city’s notorious surface-level congestion, providing a seamless gateway to the Esplanade interchange. This will effectively bridge the gap between the southern suburbs and the existing North-South (Blue Line) and East-West corridors.
A Cutting-Edge Engineering: Assystem in India’s Role in the Project
Leading the technical expertise is Assystem in India, appointed as the Detailed Design Consultant (DDC). Our mandate covers the intricate design and engineering of stations and viaducts, including certification of the same, as required for commissioning by the Commissioner of Railway Safety (CRS).
To meet aggressive timelines, we are leveraging cutting-edge Building Information Modelling (BIM) and Electronic Document Management Systems (EDMS). These tools allow for a “fast-track” design approach, enabling engineers to identify potential clashes in a virtual environment before a single brick is laid. These factors give us the ability to deploy:
- A Value Engineering: Optimised material usage to drive down construction costs.
- A Life-Cycle Efficiency of Infrastructure: Durable designs aimed at reducing long-term maintenance overheads.
- A Proactive Scheduling: Real-time updates to ensure the successful completion of the project in line with the schedule.
The Green Shift: A Masterclass in Sustainability
The Joka-IIM extension is being hailed as a landmark for sustainable urban mobility. The environmental impact is quantifiable, with a shift from road to rail.
-
- Shifts in transportation habits from road to rail: By the year 2050, the Metro is expected to absorb:
- 50% of bus commuters (translating to 1.1–1.9 lakh passenger trips daily).
- 40% of auto-rickshaw traffic and 10% of private car trips.
This habit shift is expected to result an annual reduction of ~34,320 tons of CO₂, along with significant reductions in other pollutants such as CO (~1,320 tons), HC (~330 tons), NOx (~220 tons), and PM (~44 tons)*.
*Estimates are as per Detailed Project Report (DPR)
- Energy conserved is energy generated: Beyond reducing emissions, the project incorporates a 750 V DC electric traction system featuring regenerative braking. This technology allows the trains to recover 20–30% of the energy used during transit, feeding it back into the system.
- Stations designed as ‘green hubs’: The stations are designed with solar power harnessing capabilities, LED lighting, and SCADA-based energy monitoring systems to minimise the carbon footprint of daily operations.
A Catalyst for Growth: Why This Project Matters?
For the academic community at IIM Calcutta and the growing residential pockets of the south, the Metro represents an economic unlock. By slashing travel times and enhancing “commuter comfort,” the Purple Line is expected to drive up property values and stimulate commercial growth along its path.
The Joka-IIM link stands as a testament to how meticulous design and sustainable vision can redefine a city’s pulse. For Assystem, this project is yet another step to engineer a low-carbon India.