In a first for the country, the Kolkata Metro created history by undertaking its maiden journey underwater, through a tunnel that runs inside the Hooghly River on Wednesday.

Two tunnels have been constructed beneath the Hooghly for the East-West Metro Line, which connects Howrah Maidan and Sector V in Salt Lake. 

P Uday Kumar Reddy, general manager, Kolkata Metro, described the run as a historic moment for the city of Kolkata.

"It is the first time that a train has moved below the Hoogly River. It is also the deepest station at 33 metres of depth -- a first in India. This is a historic moment for the city of Kolkata. It will take seven months to complete the trails and after that, we will be able to start regular services," Reddy said.

The underwater journey from — Howrah Maidan to Esplanade — will be conducted in trial runs for the next seven months, after which regular services on the route will be operational.

The underground route is 4.8 kms and once the stretch opens, and it will be the deepest Metro station in India.

The Metro is expected to cover the 520 meters stretch under the river Hooghly in 45 seconds. The metro line will travel at a speed of 80 km/h through tunnels that have been dug out of the Hooghly riverbed, and the journey beneath the river will take less than a minute. This 16-kilometer-long rail route comprises 10.8 kilometres of subterranean portions, with the downstream stretch of the river also being featured. The metro line will be 13 metres beneath the Hooghly River's bed, while the Howrah metro station will be up to 33 metres below ground.

Image source: Zee News