Mumbai: Mumbai Metro Rail Corporation Limited (MMRCL) undertaking the Metro3 work of Colaba–Bandra–SEEPZ, has completed more than 26 kilometres of tunnelling work so far. Moreover, it has managed to complete 13 tunnel breakthroughs out of 52.21 km of tunnelling for this project. Recently it completed the 13 tunnelling breakthrough at Vidhan Bhavan metro station on May 18.
A 95 metre long Robbins manufactured tunnel boring machines (TBM) Surya 2 weighing 600 metric tonnes did this breakthrough, according to the MMRCL. 17 tunnel boring machines (TBMs) have been lowered into 10 tunnel shafts for carrying out this work. Each consumes nearly 2, 000 units of power every hour.
The tunnelling in Mithi river is crucial as its being built underwater. According to MMRCL, by using the New Austrian Tunnelling Method (NATM) in which the traditional excavators are being used. From Monday work for casting of permanent lining started.
Adding further, MMRCL assured of coordinating with Brihanmumbai Municipal Corporation (BMC) during monsoon to ensure there will be no waterlogging due to the ongoing metro work. Moreover, the muck that is excavated everyday from the 26 underground stations, along the 33.5 km will be transported in watertight dumpers with tarpaulin to ensure it does not overflow on the road.
