Six tunnel boring machines of Chennai Metro Phase II Project wait to break through due to delays in station work

Chennai Metro Rail's tunnel boring machines sit idle due to station construction delays, awaiting breakthroughs by year-end.

Six tunnel boring machines (TBM) of Chennai Metro Rail Limited (CMRL) are currently sitting idle in different locations of the city owing to delays in station construction.

At Moolakadai, Perambur, and Mandaveli, these machines are stuck underground and haven’t been able to make a breakthrough. Only if the diaphragm wall or the station box is entirely completed can these machines break through and enter the station, before being dismantled and assigned to their next job.

While two TBMs, which started from Madhavaram High Road, are waiting at the site of the Moolakadai Metro station, two from Ayanavaram are at the site of the Perambur Metro station, and two from Greenways Road are stationed near the Mandaveli Metro station, sources said.

According to CMRL officials, though there have been numerous difficulties that caused the delays, one of the primary reasons was the decision to cancel the tender process four years ago. To develop the underground network for a part of the corridor 3 (Madhavaram to SIPCOT) of the Phase II Project, CMRL floated bids for underground station construction between Madhavaram and Taramani.

“But six tenders for station construction along the corridor were cancelled. The bidders submitted unreasonable and high quotes. As a result, we had to float bids yet again and lost time in the process. Hence, station construction was delayed on this corridor,” an official said, and added that though the TBMs started work on time, they were slowed since the station boxes were taking time to complete.

“Now, the machines have completed the work and are waiting. We are taking measures expedite the work on the stations. From next month, all the TBMs will gradually make breakthroughs before the end of the year,” the official said.

The TBMs that took off from Ayanavaram will break through the Perambur Metro station soon. Officials said the construction of the stations ran into difficulties as well. “From shifting utilities and borewells to getting permissions for traffic diversions, there were a lot of hurdles we had to overcome,” the official added.