The Mavala tunnel boring machine, which was used for the excavation of two tunnels for the Coastal Road, has been dismantled. Its last tunnel breakthrough happened on May 31. Thereafter, dismantling work was initiated and completed on July 31.
According to Manthaiya Swami, Chief Engineer of the Coastal Road, he said, "It took two months to dismantle the giant machine. The machine was lifted in five parts: cutter head, steel, and three gantries were separated."
Tunnelling work between Orange Gate and Marine Lines
This machine might be used for tunnelling work between Orange Gate and Marine Lines, as the height and width of the tunnels are required to be the same as the Coastal Road.
The Mavala machine was brought from China by the L&T company and is now owned by the company.
Manufactured by China Railway Construction Heavy Industry Company Limited (CRCHIL), the TBM was named ‘Mavala’ after Chhatrapati Shivaji Maharaj’s mountain warfare experts. Weighing over 2,800 tonnes and having a diameter of 12.19 metres (equivalent to the height of a five-storey building), Mavala is the largest TBM that has been used for tunneling in the history of India.
The excavation of the first tunnel began in January 2021 from Priyadarshini Park at Nepean Sea Road. The then Chief Minister, Uddhav Thackeray, performed a Bhoomipoojan ceremony at the launching site in Priyadarshini Park. The first breakthrough was achieved in January 2022 at the southern tip of the tunnel in Girgaon. Following this, Mavala was pushed leftwards, and in April 2022, mining for the second tunnel began. The breakthrough was achieved in the presence of Chief Minister Eknath Shinde and Deputy CM Devendra Fadnavis in May 2023.
In April 2020, Mavala arrived at Mumbai’s Jawaharlal Nehru Port from Shanghai, from where it was transferred to Priyadarshini Park via 17 different trucks since it was dismantled due to its massive size. The BMC assembled the TBM and brought it to the launching site using a 200-wheel self-propelled transporter. Civic officials said that it took three months for them to assemble the entire TBM.
In February 2023, a rubber bearing of the TBM malfunctioned, which stopped the project for a period of three months. Later, the bearing was replaced with a new one imported from Italy.