With a compact network and smaller stations, the Chennai Metro Rail Phase I extension project, inaugurated by former Chief Minister Jayalalithaa last July, is proceeding towards completion in mid-2019.
In a first milestone for the project, a tunnel boring machine (TBM) drilled through the earth from Thyagaraya College to Korukkupet on Sunday covering a distance of 1 km. The second TBM will reach this location in another two weeks. Tunnelling work, considered to be one of the most difficult parts of Metro Rail construction, was done at a record speed of 11 metres a day and hence, it was finished five months ahead of its deadline of February 2018. Usually, tunnelling is carried out at a speed of 6-8 metres a day.
According to officials of the Chennai Metro Rail Limited (CMRL), the favourable soil conditions — the stretch is largely clayey — enabled the completion of work quickly. “Intensive instrumentation and monitoring was done to ensure the structural integrity of buildings. Only minor cracks and such issues came up but they were resolved immediately. We will now focus on laying tracks and ancillary work. Nearly 30% of the station construction work is complete,” an official said.
The length of stations on this 9-km stretch has been reduced from the standard 280 metres so as to enable efficient use of space. “We want to acquire the minimum amount of land and hence, this design. But the stations being smaller doesn’t mean we have cut down on passenger facilities. We have cut down space in the non-passenger area, where machines, including the chiller plant and ventilation systems, are located and designed it in such a way as to be accommodated within this length,” he added.