India’s first underwater metro tunnel in Kolkata to get ready by 2023
Image Credit: zee news
India’s first underwater tunnel for metro connectivity in between Howrah and Kolkata is underway and will be fully functional by 2023, said officials. Of the 16.6-km-long east-west stretch, 520 metres will be under the river bed of Hooghly river. The tunnel corridor is built 33 meters below the riverbed and will connect Kolkata to Howrah.