It's been in the news for years, but Kolkata's underwater metro will ferry its first passengers very soon. The train passes through an underwater tunnel which is 520 meters in length, built 30 meters below the riverbed of the Hooghly River, for about a minute at 80 kilometers per hour. The project's foundation stone was laid in 2009, and it is expecte

It's been in the news for years, but Kolkata's underwater metro will ferry its first passengers very soon. The train passes through an underwater tunnel which is 520 meters in length, built 30 meters below the riverbed of the Hooghly River, for about a minute at 80 kilometers per hour. The project's foundation stone was laid in 2009, and it is expected to conclude by 2021 connecting the Howrah and Mahakarn Railway Stations which are two of the busiest railway stations in the world.

A revolutionary step for the Kolkata Metro Rail Corporation, will change the way people travel, but the task comes with its challenges as there are sections such as heritage structures and old buildings with brittle architectural integrity that the line goes under, making the project a complex engineering marvel.

Kolkata being one of the Indian Metropolitan cities, has the lowest road space to city space ratio at 6% making the metro an invaluable asset for citizens plagued by overflowing traffic that constricts the city. It is estimated that by 2035 the metro will become the lifeline of the city carrying close to a million people daily.