July 17, 2025: Mumbai’s Metro Line 7A project has achieved a key milestone with the completion of a 1.65-kilometre tunnel connecting Andheri (East) to Chhatrapati Shivaji Maharaj International Airport (CSMIA), bringing overall project progress to 61 per cent. The breakthrough was achieved on July 14, 2025 by Tunnel Boring Machine (TBM) T-60, nicknamed ‘Dhruv’, marking the end of a critical phase in the city’s evolving transport infrastructure.
Tunnelling for this underground section commenced on 1 September 2023, with Dhruv beginning its drive on 4 November 2023 and completing it in just over eight months. The tunnel, with an internal diameter of 5.6 metres, consists of 1,178 concrete rings—each 1.4 metres long and made up of six precast segments. Its depth varies between 12 and 28 metres, passing beneath key urban infrastructure.
Metro Line 7A spans 3.4 kilometres, combining elevated and underground segments. Of this, 2.5 kilometres are underground and will house two stations: Airport Colony and Terminal 2. The parallel down-line tunnel was completed in April 2025 by TBM ‘Disha’. With both tunnels structurally complete, upcoming work includes cross-passages and internal finishing.
The engineering team navigated complex challenges, boring beneath the Sahar Elevated Road, passing over the existing Metro Line 3, diverting a major sewer, and tunnelling near a critical water pipeline—all without disrupting surface-level infrastructure.
Once operational, Line 7A will significantly improve connectivity between northern suburbs like Mira-Bhayandar and commercial hubs such as Bandra-Kurla Complex, with a single interchange at the airport. The route will integrate with Metro Lines 2A, 3, 7, and 9, streamlining movement across the city.
The corridor is expected to be operational by 2026, becoming an essential component of Mumbai’s expanding Red Line network.
Source: Times Property
