India's first underwater metro trial

• Kolkata Metro conducted India's first underwater metro trial under the Hooghly river bed.

• The Metro rake completed its journey through a 32-metre tunnel under the Hooghly river bed.

• The Metro rake will have to cover a distance of 520 meters under the Hooghly river in 45 seconds.

• Metro is being trialled on a 4.8 km underground section from Howrah Maidan to Esplanade.

• This trial will run for the next seven months. This section is likely to be commissioned in 2023.

• After the opening of this section, Howrah will become the deepest metro station in India.

• This underwater section is a part of the East-West Metro Corridor in Kolkata.