Kolkata: India’s first underwater tunnel, being built under the Hooghly River in West Bengal at a cost of around ₹ 120 crore as part of the East West Metro Corridor, will be a blink-and-you-miss-it experience for passengers as trains will cross the 520-metre stretch in just 45 seconds.
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.
The tunnel’s construction is complete and is likely to be commissioned in December 2023 after the completion of a 2.5-km stretch between Esplanade and Sealdah on the corridor.
“The tunnel is essential for the East West Corridor and it was key. The under-the-river-alignment was the only alignment possible with residential areas and other technical issues involved,” said Kolkata Metro Rail Corporation General Manager (Civil) Sailesh Kumar.
“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.
It will take 45 seconds to cross the tunnel, he said.
The East West Corridor of the metro rail has been marred by delays and resultant cost escalations. It was approved in 2009 at a cost of ₹ 4,875 crore and a completion date of August 2015. According to officials, the cost has now increased to ₹ 8,475 crore out of which ₹ 8,383 crore has already been spent.
The tunnel will have an internal diameter of 5.55 metre and an external diameter of 6.1 metre. The spacing between the up and down tunnels will be 16.1 metre centre-to-centre.
