Maharashtra CM Devendra Fadnavis on Thursday termed the successful breakthrough of the underground tunnel of Mumbai Metro Line 7A as an engineering marvel.
The Tunnel Boring Machine (TBM) was lowered 30 meters underground and despite challenges like crossing under Mumbai Metro Line 3, Sahar elevated road, major water pipelines, and sewer lines, the breakthrough was successfully completed on Thursday, an official statement said.
In a post on X, CM Fadnavis wrote, “The TBM has successfully completed the tunnel breakthrough — a true feat of engineering marvel.”
The Mumbai Metro Line 7A on Thursday achieved a successful breakthrough of a tunnel between Andheri East and Chhatrapati Shivaji Maharaj International Airport, the officials said.
The 1.65 km tunnel between has reached a successful breakthrough and the event took place in the presence of Maharashtra Chief Minister Devendra Fadnavis, they said.
Once finished, the Mumbai Metro Line 7A will allow passengers to travel from Colaba to Vasai-Virar and Mira-Bhayandar. It will also connect directly with Mumbai Metro Line 3 at the Airport Station. The underground and elevated sections were specially planned to use minimum land in the crowded airport area.
At the event, CM Fadnavis was briefed about the project by officials. He then pressed a button to mark the breakthrough and witnessed the breakthrough process, the officials said.
🕧 12.25pm | 17-4-2025📍Mumbai.
LIVE | Media Interaction#Maharashtra #Mumbai https://t.co/6CDHKVMICC
— Devendra Fadnavis (@Dev_Fadnavis) April 17, 2025
The state minister for Skill Development, Employment, and Entrepreneurship Mangal Prabhat Lodha, MLA Parag Alavani, MMRDA Commissioner Dr. Sanjay Mukherjee, and Additional Commissioner Ashwini Mudgal were also present at the event, an official statement said.
An official statement said that the underground tunnel lies on the downline between the Mumbai Airport Terminal-2 and the airport colony station.
The segment is considered a key connection in the Mumbai Metro network.
The Mumbai Metro Line 7A is expected to improve connectivity between areas like Mira-Bhayandar, Vasai-Virar, and the airport. It will also help in linking Thane and the Navi Mumbai International Airport to the metro system.
So far, 59 per cent of the work on Mumbai Metro Line 7A is completed, the officials said.
The total length of the Mumbai Metro Line 7A is 3.4 km, with 0.94 km elevated and 2.5 km underground. There will be two stations – Airport Colony (elevated) and Chhatrapati Shivaji Maharaj International Airport (underground), the statement said.
It said that the twin tunnels will span 2.035 km, and the downline tunnel breakthrough, which started in September 2023, is now complete. The tunnel has a diameter of 6.35 meters and includes 1,180 concrete rings for lining, each specially designed in six segments.
