Metro Phase 2: Factory test held for tunnel boring machine

CHENNAI: The Chennai Metro Rail Limited (CMRL) on Saturday held a factory acceptance test for its first tunnel boring machine (TBM) for underground sections in Corridor 4.

For the underground Metro rail project in Corridor 4 from Light House station at Marina Beach to Kodambakkam flyover, the CMRL has picked up construction pace.

The underground section of the corridor, which is split into two packages (UG-01 and UG-02) is each of 4km twin tunnels.

Hence, for completing the 16 km tunneling work, as many as four TBMs is to be employed, considering both the upline and downline tunnels.

Subsequently, for the same, the TBMs manufactured by a German company Herrenknecht are being used by the CMRL's contractor ITD Cementation India Limited.

Hence, on Saturday, the factory acceptance test of TBMs which is first for UG-02 package was done at the HK factory in Tiruvallur.

The TBM has been named S1074B, which is a 6.670 M bore diameter and 110 m long earth pressure balance machine.

As per the CMRL press note, the total weight of this machine is approximately 700 MT which will now be dismantled in parts, packed and transported to its destination at Panagal Park station, T Nagar.

The construction of the TBM launching shaft which is a part of x-over structure is under progress at Panagal Park station and is expected to be ready to lower and assemble the TBM in October.

This TBM will be launched in the downline of this Corridor 4 and will mine at a maximum depth of 29 m below ground level starting from Panagal Park through Nandanam and finally scheduled to arrive at the boat club by September 2024.