In a significant milestone for the city?s metro network, Hindustan Construction Company (HCC) completed the south-bound tunnel between CSMT and Mumbai Central stations on August 2, 2019. With this, HCC became the first contractor among all packages to complete the entire length of a tunnel.

With an average drilling rate of around 8.2 m per day, the 3.82-km long tunnel from CSMT to Mumbai Central via the station boxes at Kalbadevi, Girgaon and Grant Road, was completed surmounting various challenges, according to the company.

HCC team faced several geological and urban condition challenges, including the project?s proximity to the sea, tunnelling through heterogeneous reclaimed land, congested working areas and tunnelling below some of the oldest residential buildings that are over 100 years old. Overcoming all these challenges, the experienced HCC team managed to complete the tunnelling well within the stipulated timeline.

The Mumbai Metro Rail Corporation (MMRCL) had awarded the contract to HCC in July 2016, for the design and construction of twin tunnels by tunnel boring machine (TBM) method and construction of four underground metro stations at CSMT, Kalbadevi, Girgaum and Grant Road.

The construction of station buildings is currently underway. All the station buildings are unique in design. While the CSMT station is completely a cut and cover station, the remaining three stations would be made by NATM method.