The Mumbai Metropolitan Region Development Authority’s (MMRDA) Orange Gate–Marine Drive Urban Road Tunnel project has achieved a major construction milestone, with the south-bound Tunnel Boring Machine (TBM) successfully passing beneath seven operational Central and Harbour Railway tracks without disrupting train services.
The tunnelling operation was carried out beneath one of Mumbai’s busiest railway corridors, with trains continuing to operate normally throughout the work. MMRDA said the activity was conducted under continuous monitoring and in coordination with railway authorities.
24×7 Monitoring During Tunnelling
According to MMRDA, the TBM’s movement was monitored around the clock through instrumentation and surveying systems. The work was also carried out under railway safety protocols, with coordination involving Central Railway and the Commission of Railway Safety.
The project involves tunnelling through complex urban and coastal geological conditions. The underground alignment also passes beneath existing transport infrastructure, including railway tracks and Mumbai Metro Line 3, adding to the technical challenges involved in construction.
Main Tunnel Drive Began in February
The TBM was launched by Chief Minister Devendra Fadnavis and Deputy Chief Minister and MMRDA Chairman Eknath Shinde on December 3, 2025. MMRDA has described the machine as India’s largest slurry shield TBM deployed for an urban road tunnel.
Before excavation began, the machine underwent several preparatory activities. These included connecting its backup system to the TBM shield, completing hydraulic and electrical connections and calibrating flowmeters, densitometers and pressure sensors. A probe drilling unit was also installed and tested.
The initial tunnelling drive started on January 8, 2026, with temporary tunnel rings being installed. Permanent ring installation began on January 26, while the initial drive was completed on January 31.
The TBM shifted to the main drive on February 26, with the main tunnelling operation beginning on February 28. By March 26, it had excavated 70 metres of the planned 3,720-metre drive.
7-Km Twin Tunnel Project
The Orange Gate–Marine Drive project consists of twin tunnels extending over 7 km. The first tunnel being constructed is approximately 3.45 km long and reaches depths of up to 52 metres.
The completed underground connection is expected to reduce travel time between Orange Gate and Marine Drive to around five minutes. It will also create an east-west road link connected to the Coastal Road and Atal Setu.
The project is expected to ease pressure on surface roads, while potentially reducing fuel consumption and vehicle emissions by providing a faster underground connection across the city.
Source: The Free Press Journal
