10% of tunnelling for Mumbai’s Colaba-Seepz Metro complete

Mumbai Metro Rail Corporation has completed 5km of tunnelling, is positive about completing the project by December 2021.

The Colaba-Bandra-Seepz Metro line has completed nearly 10% of tunnelling for its underground corridor. The Mumbai Metro Rail Corporation (MMRC), which is executing the 33.5km corridor, completed 5km of tunnelling across its alignment in the city.

An under-construction tunnel for the Colaba-Bandra Seepz metro corridor in Mumbai. (Anshuman Poyrekar/HT Photo)

The tunnelling is underway at four locations — Azad Maidan, Vidyanagari (Kalina), Marol and Naya Nagar (Mahim) — with eight tunnel-boring machines (TBMs) in operation.

For the construction of the underground corridor, the TBMs need to bore 52km (without stations) for both, the up and down lines.

The tunnelling commenced in November 2017 from the Naya Nagar-launching shaft in Mahim, and the TBMs are currently moving at a speed of 350m per week. “We are pleased to announce the completion of 5km of tunnelling within one year of the project’s initiation. We are positive about completing the project by December 2021,” said Ashwini Bhide, managing director, MMRC.

Corporation officials said they expect that the first TBM breakthrough will be achieved in the 4.15km Marol-MIDC-Seepz (package 7) section of the construction by September 2018.

According to the MMRC, they target to bore an average of 700-800m per week, but progress depends on the geological conditions of the location. The tunnelling work is carried out by lowering a TBM into a shaft at a depth of 25m to 30m.

Officials said that they are in the process of lowering three additional TBMs and will lower two more by July-end to increase the pace of tunnelling for the mega project.