The Chennai Metro Rail Limited (CMRL) conducted the factory acceptance test for the first tunnel boring machine (TBM) in Corridor 4 (from Lighthouse to Poonamallee bypass) in underground portion 1 of the construction.
CMRL is currently constructing the underground Metro rail project in Corridor 4 in two portions (UG 1 and UG 2), each of which contains four kilometers of twin tunnels.
For the completion of nearly 16 km of tunneling, four tunnel boring machines have been planned by CMRL, considering both the upline and downline tunnels.
As per CMRL press note, the TBMs was manufactured by German company M/s Herrenknecht, which will be utilised by contractor M/s ITD Cementation India Limited in corridor 4. Owing to this, at the HK factory in Ponneri, the first factory acceptance test of the first tunnel boring machine was held in the presence of CMRL projects director T Archunan.
On Thursday, the factory acceptance test of the first tunnel boring machine (TBM), which may be deployed at Marina Beach, was completed at the factory of TBM manufacturer Herrenknecht in Tiruvallur district.
CMRL is building an underground stretch from Lighthouse metro to Kodambakkam flyover covering eight kilometres on the 26.1km corridor-4 of phase-2 project. The 118.9km phase-2 is likely to be ready by 2026.
In a release, CMRL said four TBMs would be used to build the 8km twin-tunnels. The first TBM, which completed the factory acceptance test, is a 110m long earth pressure balance machine with a 6.67m bore diameter. The machine weighs around 700metric tonne. It will be dismantled, packed and transported to Lighthouse station site.
Subsequently, to receive the TBM, the construction of a launching shaft is currently underway in Light House Station, which is expected to be ready by May.
The TBM will be launched downline of Corridor 4 and will mine at a maximum depth of 29 meter below ground starting from Light House, Kutchery Road, Thirumaylai, Alwarpet, Bharatidasan and lastly scheduled to arrive at Boat Club in May 2025, added the press note.
CMRL’s Phase II Metro rail construction is currently undertaken for 118.9 km with 128 stations in three corridors.