Prime Minister Narendra Modi is slated to inaugurate India’s inaugural underwater metro tunnel beneath the Hooghly River in Kolkata on Wednesday. The tunnel, connecting Howrah Maidan to Esplanade, is a significant milestone for the Kolkata Metro’s East-West Metro project, encompassing a 16.5 km stretch linking Howrah on the west bank of the Hooghly to Salt Lake City on the east bank. This groundbreaking initiative establishes India’s first underwater transportation tunnel, with 10.8 km of the route running underground and 5.75 km elevated on a viaduct.
Executed by the Kolkata Metro Rail Corporation Limited (KMRCL), the project aims to address traffic congestion in Kolkata, a city steeped in a rich 300-year history, and contribute to the reduction of vehicular pollution. Notably, the Howrah metro station, a part of this section, is set to become India’s deepest metro station.
The underwater stretch beneath the Hooghly River, spanning 520 meters, is expected to be covered in an impressive 45 seconds. The completion of the Esplanade-Sealdah stretch is pending, while the Salt Lake Sector V to Sealdah stretch is already operational. The entire East-West Metro alignment, spanning 16.6 km, is anticipated to commence commercial operations between Salt Lake Sector V and Howrah Maidan by June-July.
Kolkata’s metro system has a historical significance, being India’s first metro, inaugurated 40 years ago on October 24, 1984, covering a distance of 3.40 km with five stations between Esplanade and Netaji Bhavan.
Interestingly, the concept of an underwater train tunnel for Kolkata dates back to the British era when Bengal-born British engineer Harley Dalrymple-Hay envisioned a groundbreaking 10.6 km underground railway connecting Kolkata and Howrah over a century ago. Although the ambitious project, which included a tunnel beneath the Hooghly River and 10 stops, was not realized due to funding challenges and concerns about the city’s soil properties, it laid the foundation for the recent achievement. In 1928, CESC, the city’s electricity supply company, collaborated with Harley to construct a tunnel under the Hooghly for power cables. This tunnel, completed in 1931, remains in use for power cables, showcasing Kolkata’s enduring connection with pioneering engineering feats.