Machine starts boring under Hooghly to build tunnel for East-West Metro

Kolkata: A tunnel-boring machine (TBM) will start its drive just below the riverbed to make the tunnel of the East West Metro from Friday.

The machine that had started its journey from Howrah Maidan on April 16 last year is all set to bore through the mud and silt for three months under the riverbed before it reaches the Strand Road.

It would be the biggest challenge for the East - West Metro project that will connect Salt Lake Sector V with Howrah Maidan - a distance of more than 16 kilometres.

“We are a few metres away from the riverbed and are hopeful of digging exactly under the river from tomorrow,” an engineer of the Kolkata Metro Railway Corporation Ltd (KMRCL) - the implementing agency of the Rs 5,000-crore East-West Metro project said.

The TBM is expected to reach the other side of the river by September this year. “All precautionary measures have been taken and there is nothing to bother about.

We will be working at a depth of 30 metres below the water level - 12 metre below water level and again 18 metres underneath the soil - level,” the engineer added.

The tunnel will cover 520 metres of the riverbed before culminating at Armenian Ghat on Strand Road.

After the Thames, Hooghly will be the second river to have an under - ground tunnel for Metro Rail once the work is finished. “It is the first time in the country that boring for a railway tunnel under a riverbed is being done,” a KMRCL official said.

The TBM Machine procured from the German company Herenacot will require 6000 kilovolt power.

“We have made arrangements for power facilities to ensure that work does not get stalled due to lack of power,” the official added.