According to News18, Kolkata's East West Metro, which is approximately 16.6 km long, will ferry an estimated 1 million people per day by 2035. 

Source: Urban Transport News

The project that is expected to be complete by 2021, will also feature India's first ever underwater tunnel. 

Source: Times of India

The 520-metre twin tunnel, one east-bound and the other west-bound, has been built 30 metres below the riverbed, which means commuters will be underwater for close to a minute. 

Source: News On Screen

This will happen when the train they board passes between Howrah and Mahakaran metro stations, reports News18


The speed of the train is expected to be 80 km per hour when it passes through the tunnel.  

Source: News18

The 5-km stretch between Salt Lake & Howrah was inspected on Tuesday, July 23 and is expected to be operational soon.