Maharashtra Chief Minister Devendra Fadnavis on Wednesday launched the Tunnel Boring Machine (TBM) for the state’s ambitious 9.23-km underground road corridor that will connect Orange Gate on the Eastern Freeway to Marine Drive. The launch marks a major milestone in one of Mumbai’s most significant infrastructure projects aimed at strengthening east–west connectivity.
Fadnavis was joined at the ceremony by Deputy Chief Minister Eknath Shinde, Maharashtra Assembly Speaker Rahul Narwekar, and several senior officials and dignitaries. With the activation of the TBM, full-fledged tunnelling work on the corridor has officially commenced.
Estimated at Rs 8,056 crore and scheduled for completion in 54 months, the project includes the design and construction of a nearly 10-km roadway, of which approximately 7 km will be entirely underground. Once operational, the corridor is expected to substantially reduce travel time between the city’s eastern and southern regions by 15 to 20 minutes. Officials also highlighted the project’s potential to cut fuel consumption and ease both air and noise pollution across key traffic-heavy zones.
According to engineers, the tunnel is the first of its kind in India because of its depth and alignment through densely populated urban areas. It will run beneath major transport corridors, including the Central and Western Railway lines, as well as the Mumbai Metro Line 3 (Aqua Line). At its deepest point, the tunnel will reach nearly 50 metres below the surface, with an average depth ranging from 12 to 52 metres.
The project features twin tunnels, each equipped with two 3.2-metre traffic lanes and an additional 2.5-metre emergency lane. Vehicles will be allowed to travel at a maximum speed of 80 kmph. For safety, cross passages will link the two tunnels every 300 metres. The plan also includes advanced ventilation systems, fire-resistant materials, modern illumination, and an Intelligent Transport System (ITS) to improve monitoring and traffic flow.
Officials said the decision to adopt an underground alignment was crucial to minimising land acquisition and reducing disruptions at ground level. The corridor will ultimately integrate with major transport initiatives, including the Coastal Road and the Atal Setu, enhancing Mumbai’s larger mobility network.
Tunnelling will be executed using a slurry-shield TBM, a technology well-suited to Mumbai’s coastal geology and previously used in the Mumbai Coastal Road Project. The refurbished and OEM-supervised machine features a 12.19-metre cutter head, measures 82 metres in length, and weighs roughly 2,400 tonnes.
