Mumbai: Amid controversies and oppositions, Mumbai Metro Rail Corporation (MMRC) completed the stacking and excavation work for the Metro-3 corridor (Colaba-Bandra-SEEPZ) this year, and tunnel work began in early November. At the beginning of the year, the MMRC placed an order for 17 tunnel boring machines (TBM) to carry out the corridor tunnel work. Of these, five have arrived in the city. The first tunnel boring machine was lowered at the Naya Nagar launch pit in Mahim in September. It took him almost 45 days to assemble the entire machine, which was lowered in three separate parts. According to the
MMRC, this TBM has completed 50 meters. The machine is expected to leave Dadar in September 2018.
The machines have also been downloaded at Vidya Nagari in Kalina, Azad Maidan near Chhatrapati Shivaji Terminus and Pali Ground in Marol Naka. The tunneling work is carried out 25 meters below the surface of the earth, and the machine can cover a distance of approximately 12 meters per day. In the next year, more tunneling works of this type can be expected. According to Ashwini Bhide, CEO of MMRC, all TBMs will reappear at the end of 2019.
The TBM weighs around 700-800 tons with a diameter of 6.4 meters, the 100 meter long machine will help to build a tunnel with a finishing size of 5.8 meters. The 33.5 km long underground corridor will start operating in December 2021.