Chennai Metro Rail’s tunnel boring machine from Ayanavaram to make a breakthrough at Perambur in two months

Chennai Metro Rail's TBM Kalvarayan to breakthrough at Perambur in January, connecting Ayanavaram in Phase II project.

Chennai Metro Rail’s tunnel boring machine (TBM) Kalvarayan from Ayanavaram will finally make a breakthrough at Perambur by the end of January next year. 

In the ₹63,846-crore Phase II project, areas like Ayanavaram and Perambur, will be built with underground stations and will be linked by Chennai Metro Rail network in future. The small stretch between Ayanavaram and Perambur falls under the corridor 3 of the project, which starts in the northern part of the city in Madhavaram and terminates in the south at SIPCOT. It runs for 45.4 km and makes it the longest corridor in the Chennai Metro Rail network. 

According to officials of Chennai Metro Rail Limited (CMRL), the TBM Kalvarayan has already bored 866 metre and is waiting outside the station at Perambur to make a breakthrough. “It has been quite difficult and time consuming to build the shaft (a part of station construction) here. Though it was to be completed before the end of the year , there have been quite a few challenges in building the shaft. We will finish the base slab construction too and by the end of January, the machine will enter the station,” an official said. 

In August last year, the machine had started from Ayanavaram. However, due to the delay in constructing the diaphragm wall and station construction, this TBM has been waiting for a breakthrough. Not just this TBM, a few other TBMs in the city had to wait for a breakthrough as well because the station construction began late due to issues related to the tendering process.

After the first TBM ‘Kalvarayan’ makes the breakthrough, the second TBM ‘Melagiri’ will pick up pace. Similar to the ‘Kalvarayan’ TBM that drilled under the suburban railway track at Perambur, the second machine, too, will build a second tunnel under these tracks.

“It will take a week to bore under the tracks and according to the restrictions given by the Southern Railways, we will carry it out. The monitoring of the TBM parameters will be done every hour when the tunnelling goes on in this stretch,” another official said.