Kolkata: Kolkata will soon have an underwater Metro which will pass through tunnels several feet under the Hooghly.
The first underwater transportation tunnel of India is ready with the second one nearing completion.
The Kolkata Metro transportation tunnel is unique because never before in the history of the country has a tunnel been made under a flowing river.
The tunnel has been constructed 30 metres below riverbed, just a few metres away from the famous Howrah Bridge, built in the last century to connect Howrah and Kolkata.
It will be connecting two main terminals: Howrah and Sealdah – each of which has a footfall of about 10-12 lakh passengers per day. These type of tunnel-boring machines, which we call ‘earth pressure balancing tunnel boring machines’, have been used for the first time in Eastern India.
More than 10 lakh tonne of mud has been dug out for the construction of this tunnel. The tunnel-boring machines were used for the first time in eastern India.
The entire 16.6-kilometre stretch of the first tunnel is ready. The second tunnel is yet to be completed. Of the entire length, 10.8 kms is underground and around one kilometre is underwater.