PM Modi Inaugurates India's First Underwater Metro Tunnel in Kolkata

On Wednesday, Prime Minister Narendra Modi will open the Howrah Maidan-Esplanade segment of the Calcutta Metro's East-West route, marking the beginning of India's first underwater metro transit project and an engineering wonder.

The Howrah Metro station will be the nation's deepest metro station. The Howrah Maidan-Esplanade segment is a ground-breaking addition to the city's transportation network and is hailed as the first transportation tunnel "under any mighty river in India".

This achievement, which is hidden under the Hooghly River that divides the twin towns of Howrah and Calcutta, is a monument to the inventiveness of engineers.

In April 2023, Calcutta Metro achieved a significant milestone when its rakes successfully completed a trial run down a tunnel 32 meters below the Hooghly River's surface—the first of its kind in India.

Researchers have found that the British originally proposed the notion of an underwater transit system along the lines of London in 1921.

However, the proposal was never implemented since the findings of the soil testing were negative. The project proposal was shelved and they were compelled to give up on the notion, Aloke Kumar, an associate professor at IIM-Calcutta, told PTI.

According to Kumar, who had studied trains in great detail, the concept was once again promoted by ABA Ghani Khan Chowdhury, the railway minister at the time, in the 1980s.

However, the project was never implemented. The building work started in 2009 after receiving approval from the UPA administration in 2008, according to a former railway official.

However, he continued, the project was delayed by escalating costs and political obstacles.

It is a crucial section of the East-West Metro network, spanning 4.8 kilometers between Howrah Maidan and Esplanade and linking important locations including Salt Lake Sector V, an IT cluster.

The Metro Railway released a statement stating that the 4.8-km East-West Metro line from Howrah Maidan to Esplanade was constructed at an estimated cost of Rs 4,965 crore.

10.8 km of the 16.6 km long East-West Metro corridor—including the tunnel under the river—are subterranean.

A Metro train is anticipated to cross the 520-meter section under the river in 45 seconds, providing not only speed but also a smooth and timely means of transit, hence augmenting Calcutta's urban mobility and connection.

"This corridor, once fully commissioned, will also solve the perennial traffic congestion and improve air quality by reducing carbon footprint," added the statement.

The use of metro services after disembarking at the Howrah train station will be quite advantageous for travelers from Hooghly, Howrah, Medinipur, and other states.

Officials claim that construction on the East-West route started in 2009 and that digging under Hooghly started in 2017.

Due to an aquifer rupture at Bowbazar in downtown Calcutta on August 31, 2019, which caused serious ground subsidence and the collapse of multiple structures, as well as two other water leakage occurrences at the same location during digging and construction work in 2022, the project has been delayed.

Currently, the corridor's section from Salt Lake Sector V to Sealdah is used for commercial purposes.

Additionally, the PM will open the Taratala-Majerhat Metro segment of the Joka-Esplanade Metro and the Kavi Subhash-Hemanta Mukhopadhyay section of the New Garia-Airport Metro.