The construction work of the second and final 1.65 km-long tunnel on the Mumbai Metro Line 7A, which will connect Andheri (East) and Chhatrapati Shivaji Maharaj International Airport (CSMIA), has been completed. With this, the metro line 7A has achieved a big milestone. The tunnel boring machine (TBM) T-60 made the breakthrough on July 14, 2025, which was a major step forward for this vital infrastructure project. The TBM drive started on November 4, 2023, and tunnelling started on September 1, 2023, under the direction of the Mumbai Metropolitan Region Development Authority (MMRDA). 1,178 rings, each 1.4 meters long and composed of six segments, were used to construct the tunnel, which has a completed diameter of 5.6 meters. The tunnel is between 12 and 28 meters deep. There is a 2.5 km subterranean portion of the 3.4 km Metro Line 7A. It is intended as a partially elevated and partially underground alignment, and it has two underground stations: Airport Colony and T2 Airport.
When this metro line becomes operational, it will provide a seamless interchange at the CSMIA station with Metro Line 3. This line will ensure that there is better connectivity for its commuters.
A senior official associated with this project said that the commuters from Mira-Bhayander could reach BKC with just one interchange at the airport station.
The project is expected to be ready by 2026. As of now the 61% of the construction work is completed. Many engineering challenges are tackled by the authorities, which include construction under the Sahar Elevated Road, an overpass above Metro Line 3, diversion of a major sewer line, and crossing an underground water pipeline. The Metro Line 7A will integrate with Metro Lines 2A, 7, 9, and 3. This integration will strengthen Mumbai’s metro network and ease travel across the city.