By the middle of 2023, the tunnel boring machine is likely to arrive in chennai and the construction of twin tunnels under Marina Beach for the driverless metro trains operations would begin.
At the factory of TBM manufacturer Herrenknecht in Thiruvallur district, the factory acceptance test for the first tunnel boring machine or TBM that might be used at the Marina Beach was conducted yesterday.
It is well known to us that CMRL is constructing an underground stretch from Lighthouse metro to Kodambakkam flyover covering 8km on the 26.1 km corridor4 of phase2 project. By 2026, the 118.9km metro phase 2 would be completed. To build 8km tunnels, 4 TBM would be utilised and this was as per CMRL in a release.
It is noteworthy that the first TBM that completed the factory acceptance test would be 110m long earth pressure balance machine with 6.67m bore diameter and the machine weighs about 700 metric tonnes. Point is that later it would be dismantled,packed and shifted to the lighthouse station site.
According to the release from CMRL, the construction of TBM launching shaft is going on now at the Lighthouse station and in May 2023 it will be ready to receive the TBM.