Infrastructure

Chennai Metro: First Tunnelling Work Of Phase II Project To Begin In Mid-October In Madhavaram

  • One tunnel boring machine will commence the initial tunnelling operation at Madhavaram and drill toward Kellys to construct an underground section.
  • A second TBM will be deployed a month later.

V Bhagya SubhashiniSep 27, 2022, 11:13 AM | Updated 11:12 AM IST
A tunnel boring machine (TBM) being lowered down a shaft. (Kunal Patil/Hindustan Times via Getty Images)

A tunnel boring machine (TBM) being lowered down a shaft. (Kunal Patil/Hindustan Times via Getty Images)


Chennai Metro Rail Limited (CMRL) will begin tunnelling in Madhavaram in mid-October as part of Chennai Metro Rail's Phase II project.

The expansion of Chennai Metro Phase II consists of three corridors:

  • Corridor 3 - from Madhavaram to SIPCOT (45.8 km),

  • Corridor 4 - from Lighthouse to Poonamalle Bypass (26.1 km),


  • The estimated cost of the project is‌‌ Rs 63,246 crore. The underground stretches from Madhavaram to Kellys (a part of the Madhavaram-SIPCOT corridor) will be worked on first.

    According to CMRL officials, the first tunnel boring machine (TBM) that arrived from China more than two months ago was lowered into the construction site last week.

    The two 6.61m TBM machines manufactured by Terratec in China will be used to build approximately 9 km of twin tunnels (a total of 18 km) on Line-3's Venugopal Nagar - Kellys section.

    Map of Chennai Metro Rail Project Phase - II Source : CMRL

    One TBM will commence the initial tunnelling operation at Madhavaram and drill toward Kellys to construct an underground section. A second TBM will be deployed a month later.

    The TBM launched at Madhavaram may take months to reach Kellys, and the length of time would primarily rely on the geological conditions.

    "Usually, we give a gap of a few weeks between deploying the two TBMs. Operating with a space of 100m or more is always better. Before starting the tunnelling work at Madhavaram, we completed surveys and utility diversion work. We have to track and plug the borewells within residences," an official said, reports The Hindu.

    Later this year, two more TBMs will begin service between Kellys and Taramani.


    Another 5.8 km underground section of Corridor 5 connects Madhavaram and Shollinganallur, which spans 47 km.

    The Phase II project will require 23 TBMs, and the additional equipment is expected to arrive shortly. The underground work will gradually spread to other parts of the city.

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