HOWRAH: Passengers will experience India's first underwater tunnel in a blink-and-you-miss-it moment as trains will transmit the 520-metre section in only 45 seconds. The tunnel is being built under the Hooghly River in West Bengal at a cost of about Rs 120 crore as part of the East West Metro Corridor.
The tunnel -- the Indian version of Eurostar's London-Paris corridor -- is 13 metre below the riverbed and 33 metre below ground level. The 520-metre tunnel is part of the East West Metro Corridor of Kolkata -- from the IT hub of Salt Lake Sector V in the east to Howrah Maidan in the west across the river.
After the completion of the 2.5-km segment in the corridor between Esplanade and Sealdah, the tunnel's construction is finished and is anticipated to be put into service in December 2023.
Kolkata Metro Rail Corporation General Manager (Civil) Sailesh Kumar said that "The tunnel is essential for the East West Corridor and it was vital. The under-the-river-alignment was the only alignment possible with residential areas and other technical issues involved."
"This metro route between Howrah and Sealdah cuts down the commute time to 40 minutes as against 1.5 hours by road. It will also ease congestion at both ends," he said.
The tunnel's external diameter will be 6.1 metres, and its internal diameter will be 5.55 metres. The up and down tunnels will be 16.1 metres apart centre to centre.
The National Fire Protection Association (NFPA) guidelines are being followed by providing emergency escape shafts inside the tunnel that can reach a length of 760 metres. For the protection of the passengers, evacuation shafts are available at Howrah Station in the west and Strand Road in the east.