Four firms bid for Chennai Metro phase II project tunnelling work.

Four firms have bid for the construction of a 21 km underground stretch for phase II project of Chennai Metro Rail.

Gulermak, Tata Projects, L&T and Shanghai Tunnel Engineering Co (Singapore) Pte Ltd-Woh Hup Pte Ltd (joint venture) have submitted their bids. While the entire phase II project covers a length of 118.9 km, Chennai Metro Rail Limited (CMRL) will build the project by giving out contracts in sections.

Initially, two tenders were floated for the construction of tunnels between Venugopal Nagar in Madhavaram to Kellys (9 km) and then from Kellys to Taramani (12 km). After technical and financial bids are finalised, a contractor would be chosen to build the tunnels in a few months, sources said.

Two tunnel boring machines (TBM) each will operate in these two stretches — one for onward and another for return tracks. Though TBMs can bore at a speed of 5-10 m a day on an average, geological conditions will determine the actual working speed.

According to the officials of CMRL, they decided to start this first since tunnelling work was the toughest and consumed the maximum amount of time in a project.

“We hope to carry out this work as fast as we can but it will depend highly on the geological conditions in these stretches. To ensure disruptions are less, we have done soil testing every 25 m at hundreds of spots throughout the city. Despite that, there could be some challenges,” an official said.

Sources said it could take nearly four years to finish tunnelling in this stretch.

THE HINDU