Chennai Metro Rail's tunnel boring machine creates corridor under Chetpet lake and railway track

The Hindu

30-04-2025

After boring below the Chetpet lake and Chetpet suburban railway station, Chennai Metro Rail's tunnel boring machine Thamirabarani will reach the Kilpauk Medical College (KMC) station by September this year.
A part of corridor 3 of the 118.9-km phase II project, this stretch begins at Madhavaram, traverses through several key areas of the city, including Chetpet, KMC, Nungambakkam, Mylapore, and Adyar, and ends at Siruseri. The length of corridor 3 is 45.8 km.
The Chetpet and Kilpauk stations will also serve as good examples of multi-modal integration. Commuters who travel via the suburban line from areas like Kodambakkam or Mambalam can get off at Chetpet and switch to the metro. Similarly, at KMC, the phase I and phase II networks meet, allowing commuters to easily change trains and travel to various localities.
According to officials of Chennai Metro Rail Limited (CMRL), the tunnel boring machine must cover a distance of 677 metres to link Chetpet with KMC, and so far, it has drilled nearly 260 metres. 'After it was launched, the machine first bored underneath the suburban station. It took 41 days for it to cross the station. But under the track, the TBM bored for a brief period only, and during this time, the long-distance and high-speed trains had speed restrictions imposed by Southern Railway, and the trains didn't cross 40 kmph as a precautionary measure. The TBM bored at a depth of 18 metres from the ground,' an official said.
To cross the lake, the Thamirabharani TBM had to drill at a depth of nearly 17 metres for 43 days, he added.
Suhasini Fredrick, a resident of Harrington Road for over two decades, said it is quite exciting that in a couple of years, she will be travelling by a train under the lake. 'While one of my siblings lives in Madhavaram, the other resides in Adyar. So, for someone like me, my travel time would be reduced by half to commute to these areas by the Chennai Metro Rail system. Several people travel from Chetpet to the IT corridor and ECR, and they would greatly benefit from the upcoming station at Chetpet,' she added. She said that if long-distance trains stop at Chetpet, then many can alight here and head home.
Sources said the Chetpet-KMC stretch is a short one, but the machine was slowed down as it took some time to build the shaft at the KMC station. This station's work too, like a quite a few stations along this corridor, was delayed because of a tender cancellation a few years ago, as the bidders had placed a steep quote.