Mumbai’s ambitious underground road tunnel connecting Orange Gate and Marine Drive has reached a key construction milestone, with the tunnel boring machine (TBM) completing 70 metres of excavation after entering its main drive phase.
The twin-tunnel project, being executed by the Mumbai Metropolitan Region Development Authority, is considered one of India’s most complex urban tunnelling initiatives. The slurry shield TBM deployed for the project is reportedly the largest ever used for an urban road tunnel in the country, highlighting the scale and engineering sophistication involved.
The machine transitioned from its initial drive stage to full-scale tunnelling on 26 February, with continuous excavation beginning two days later. By 26 March, it had progressed 70 metres along the planned 3,720-metre stretch of the first tunnel.
The project was formally launched on 3 December 2025 by Devendra Fadnavis and Eknath Shinde, who also serves as MMRDA chairman. Following the launch, several weeks were spent on backend preparations, including installation of hydraulic systems, electrical components, and sensors. Initial tunnelling operations began on 8 January 2026.
Once completed, the twin tunnels will extend over 7 km, with the first tunnel measuring 3.45 km. The alignment reaches depths of up to 52 metres and passes beneath key infrastructure, including suburban railway lines and Mumbai Metro Line 3, requiring high levels of precision.
The project is expected to significantly cut travel time between Orange Gate and Marine Drive to around five minutes. It will also integrate with major transport links such as the Coastal Road and Mumbai Trans Harbour Link, improving connectivity across South Mumbai while reducing congestion, fuel consumption, and emissions.
Source: Swarajya
