Tunnel boring under Hooghly kicks off

The tunnel-boring machine (TBM) of the East-West Metro started boring below the riverbed for making a tunnel on Friday.

The final journey of the TMB would be under the river Hooghly, measuring around 2 km from Howrah to Kolkata. It may be mentioned that the TBM had started boring the tunnel from Howrah Maidan on April 16, last year. Now, it has reach till the riverbed.

On Friday, the engineers and the site-workers arranged a prayer and Ganga Aarti before the machine started working.

"The TBM will work non-stop for around 8 to 10 months. But we cannot run it if any technical problem suddenly appears. This is a German machine which requires 6,000 kV power," said an engineer.

"The Kolkata Metro Railway Corporation Ltd (KMRCL), the implementing agency of the East-West Metro, reached under the riverbed. We have taken all the precautionary measures," the engineer added. On Friday, the TMB was stationed around 30 metre below the surface and from here, it will go deeper. From Strand Road, it had reached the deepest point on its journey which was 40 metre below the surface, before starting to climb up again. According to the the sight-workers, the TMB machine would reach to the other side of the river Hooghly by September–October. Initially, the workers would work 30 metre below the water level and then they would climb up to 12 metre below water and then they again go down to 18 metre below the level of water.

The 14.67 km East West Metro will connect Salt lake Sector-V to Howrah Maidan. The elevated portion of the route is 5.77 km and the underground portion is 8.90 km. It will be the first-of -its-kind project in India.