Mumbai Metro Aqua Line 3: Six New Stations Ready; Acharya Atre Chowk Stretch To Open By March 2025

The Mumbai Metro Aqua Line 3 announced on Tuesday that it has started train movement towards the Kotak BKC Metro station on the Dharavi to Acharya Atre Chowk stretch. This stretch is 9.77 kilometres long and includes six stations.

A spokesperson for the Metro stated, "Train movement has been completed until the Acharya Atre Chowk station for trials. We expect this stretch to open for commercial operations by March 2025, pending inspection and safety certifications by the Commissioner of Metro Rail Safety."

Photo Credit: PTI

This development is part of what is termed Phase 2A. A video shared on social media showed visuals of the trials and the stations. The final phase of the Aqua Line is expected to be completed in Colaba by the end of 2025. Once operational, the journey from JVLR to Acharya Atre Chowk will take approximately 39 minutes.

Mumbai Metro Aqua Line 3: Challenges

Officials reported that constructing the line under the Mithi River posed significant challenges. This was the first time such a project was attempted in these soil conditions, meaning there was no prior example to follow. The railway line includes a twin-tunnel section running beneath the Mithi River between the Bandra Kurla Complex (BKC) and Dharavi stations. The construction utilised tunnel boring machines (TBMs) named Godavari 3 and Godavari 4, following the New Australian Tunneling Method, which involves sequential excavation.

Of the total 3-kilometre twin tunnel section between BKC and Dharavi, approximately 2 kilometres pass beneath an expanded water body, including a 500-metre section of the active Mithi River channel. To address these challenges, custom-designed earth balance machines were created specifically for tunnelling underwater. These advanced machines help maintain natural pressure at the tunnel face, preventing land settlement, while efficiently managing excavated materials and controlling water seepage.

Mumbai Metro Aqua Line 3: Structure Below The Mithi River

The railway line is located 9.57 metres below the Mithi River bed. Beneath the river's water flow, there is a layer of slush, followed by brecciated basalt rock. The machines operated in layers of Grade 3/4 and Grade 1/2 brecciated basalt rock.

Mumbai Metro Aqua Line 3: Waterproofing Innovations

To combat the likelihood of water ingress, a special gasket system was designed for this area. Precast concrete segment rings feature mushroom-type gaskets that ensure watertightness. Additionally, a layer of hydrophilic gaskets swells upon contact with water, enhancing the watertight integrity of the joints.

Mumbai Metro Aqua Line 3: Station Depths And Locations

Dharavi station, located next to the Kotak BKC station, is situated 18 to 18.5 metres below the ground. The six stations along the stretch between Kotak BKC and Acharya Atre Chowk are Dharavi, Sitaladevi, Dadar, Siddhivinayak, Worli, and Acharya Atre Chowk.