Apr 17, 2023
By: Srishti MaganIndian Railways completed 170 years on April 16. Right before its anniversary, India launched its first underwater metro in Kolkata – the same city where India’s first metro line opened in 1984.
Credit: Twitter
Kolkata metro’s newest line passes underneath the city’s Hooghly River. It completed its maiden test run last week, on April 12, crossing the Hooghly River from Mahakaran to Howrah Maidan.
Credit: Twitter
“This is a historic moment for Metro Railway. This is a revolutionary step in providing a modern transport system to the people of Kolkata and suburbs,” said Kausik Mitra, chief public relations officer for the Kolkata metro system.
Credit: Kolkata-Metro
The metro can cover an area of 520 meters beneath the river in just 45 seconds. Once operational, Howrah will be India’s deepest metro station, with the tunnels over 30 meters below the water.
Credit: Kolkata-Metro
The contract to build the river tunnels was awarded in 2010. India’s Afcons Infrastructure entered a joint venture with Russia’s Transtonnelstroy (which built a road under the sea in Iran) for the project. The actual tunneling started in 2017 – and was completed in just 67 days.
Credit: BCCL
Only part of the entire 16-km stretch is underwater and as per TOI, the tunnels have been built in such a way that you won’t know the underwater part from the land. The train, in itself, is no different from the regular metro - the engineering feat lies in building the river tunnels.
Credit: Kolkata-Metro
Unlike conventional tunneling, river tunneling has to be continuous to avoid leakages due to stoppages. Thus, a crew was deployed 24x7. Hydrophilic gaskets have been placed in between the concrete of the river tunnels to ensure that no drop of water enters the tunnel.
Credit: BCCL
Reports state that the trial runs will be conducted for the next seven months. Post this, the metro line will open to the public in November this year, connecting the soon-to-open metro station of Howrah Maidan and the existing station of Esplanade on the opposite side of the river.
Credit: Kolkata-Metro
Due to various operational setbacks, including land subsidence, cave-in zones and congestion, a truncated 4.8 km stretch will be operational this year. The entire stretch (from Sector V to Howrah Maidan) is expected to be completed in the next two years. Once complete it will take only 27 minutes to traverse it.
Credit: Afcons
Apart from Kolkata’s underwater metro, the country’s first bullet train from Mumbai to Ahmedabad will also have a 7-km underwater stretch. The train will cover a total distance of 508 km and is expected to launch by the end of 2023, as per reports.
Credit: NHRSCL
The world’s first underwater train line opened in London, under the Thames River in 1843. Today, Japan, Paris, and Istanbul are some of the places to have underwater railway lines.
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