India's ambitious 'Atmanirbhar Bharat' project, the underwater metro in Kolkata, is set to commence operations for commuters by the end of 2023. The project involves the construction of a tunnel under the river Hooghly, a remarkable engineering feat accomplished by Indian engineers. The tunnel, with an internal diameter of 5.55 meters and external diameter of 6.1 meters, has been built using a tunnel-boring machine (TBM). It runs 32 meters below water level, making it an engineering marvel. The underwater railway system will connect Howrah Maidan station to Mahakaran metro station, offering passengers a unique experience of traveling beneath the river. Sanjay Banerjee, the General Manager Civil of Kolkata Metro Rail Cooperation Limited, highlighted the challenges faced during the project, particularly the careful planning required due to the densely populated areas of Kolkata and the presence of existing buildings. Despite these challenges, the project has made significant progress, with a section of the underground route already operational from Phoolbagan to Sealdah. The project emphasises the indigenisation of technology, with Indian companies leading the way and Indian engineers playing a pivotal role. The construction of the underwater metro serves as a prime example of the 'Atmanirbhar' initiative, showcasing the capabilities and expertise of Indian engineers. The underwater tunnel spans a length of 520 metres, reaching a depth of 16 metres below the riverbed at its deepest point. The construction of the tunnel, which connects Howrah station complex to Armenian Ghat, was completed in a record time of 66 days. This underwater rail system marks a significant milestone as the first subaqueous tunnel beneath a major river in India. The authorities aim to open the underwater metro for commercial use by December 2023, providing the people of Kolkata with an advanced and efficient mode of transportation and contributing to the city's urban development.