Mumbai, April 17 (IANS) The breakthrough of the 1.65-kilometre underground tunnel on Mumbai Metro Line 7A, from Chhatrapati Shivaji Maharaj International Airport (T2) to Andheri East, was successfully completed on Thursday in the presence of Chief Minister Devendra Fadnavis.
The tunnel is being constructed by the Mumbai Metropolitan Region Development Authority (MMRDA).
The Chief Minister reviewed detailed information about the project from officials and initiated the breakthrough by pressing the button. He later inspected the work on-site. This particular tunnel is located on the downline of Metro Line 7A, between the Chhatrapati Shivaji Maharaj International Airport station and the Airport Colony station.
This metro link is a crucial segment of the Mumbai metropolitan area's expanding metro network. With this line, Mira-Bhayander and further up to Vasai-Virar will be connected to the international airport. Eventually, the Thane and Navi Mumbai International Airports will also be linked via metro. Currently, 59 per cent of the total work on Metro Line 7A has been completed.
According to the MMRDA, Metro Line 7A stretches over 3.4 kilometres, 0.94 km is elevated, and 2.5 km is underground. The line will have two stations: one elevated at Airport Colony and the other underground at the Chhatrapati Shivaji Maharaj International Airport. Out of the total length, 0.57 km is elevated, while the twin tunnels are 2.035 km long.
The first tunnel drive for the downline began on September 1, 2023. The 1.65-km tunnel includes 1,180 pre-cast rings used for lining, each ring specially designed and divided into six parts, with a tunnel diameter of 6.35 meters.
In September 2023, the Tunnel Boring Machine (TBM) was lowered 30 meters underground.
Despite multiple engineering challenges, passing under Metro Line 3, the Sahar Elevated Road, major sewer and water pipelines, the breakthrough was completed successfully. This new line will allow passengers to travel comfortably from Colaba to Vasai-Virar and Mira-Bhayander. It will also provide seamless integration with other metro lines in the city, including Metro Line 3 (Colaba-Bandra-SEEPZ), which connects to the underground airport station.
The blend of elevated and underground alignments ensures minimal land usage in densely populated airport zones, enabling a smoother metro construction process.