India to get its first underwater metro tunnel in Kolkata today | 6 things to know

Prime Minister Narendra Modi will inaugurate the Howrah Maidan-Esplanade section of Kolkata Metro's East-West corridor today, heralding India's first venture into underwater metro services, deemed as an engineering marvel.

India's first underwater tunnel, being constructed beneath the Hooghly River, will provide passengers with a blink-and-you-miss-it experience, as trains traverse the 520-metre stretch in just 45 seconds, reported PTI.

Although the inauguration will take place today, the passenger services will begin at a later date, CPRO Metro Railways Kaushik Mitra was quoted as saying.

Here's all you need to know about the metro project:

• The Howrah Maidan-Esplanade section is a significant addition to the metropolis' transportation network, being heralded as the first transportation tunnel "under any mighty river in India". It boasts the country's deepest metro station, the Howrah Metro station.

• The tunnel, comparable to Eurostar's London-Paris corridor, lies 13 metres below the riverbed and 33 metres below ground level.

• Spanning a 4.8-kilometre stretch between Howrah Maidan and Esplanade, this segment is a crucial part of the East-West Metro corridor, linking key areas such as the IT hub Salt Lake Sector V.

• The 4.8-km stretch of East-West Metro from Howrah Maidan to Esplanade has been built at a cost of Rs 4,965 crore, PTI quoted a statement from Metro Railway as saying.

• Of the total 16.6 kilometres of the East-West Metro corridor, 10.8 kilometres are underground, including the tunnel beneath the River Hooghly.

• According to officials, work on the East-West Metro corridor began in 2009, with tunneling under the River Hooghly commencing in 2017.

The project encountered delays in the past due to an aquifer burst at Bowbazar in central Kolkata on August 31, 2019. This resulted in severe ground subsidence, the collapse of several buildings in the area, and two additional water leakage incidents at the same site in 2022 during tunneling and construction work.

In addition to the metro project, the Prime Minister will also inaugurate the Kavi Subhash-Hemanta Mukhopadhyay section of the New Garia-Airport Metro and the Taratala-Majerhat Metro section of the Joka-Esplanade Metro.

(With PTI inputs)