India’s First Underwater Metro Line Opened In The Kolkata

India's First Underwater Metro Line
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India has already made a big step in transport by commissioning the first underwater metro line in Kolkata. The line is a part of the East-West corridor of Kolkata Metro. It is this fresh metro route that links metropolises together and portrays the country’s advancement in its inter-city infrastructures. Let us discuss this in simpler words, emphasizing how BIM was instrumental in this project.

The Underwater Metro Route

Inauguration and Cost

  • Inauguration: Narendra Modi, the present Prime Minister of India, opens the first-ever underwater metro route facility in Kolkata on the 6th of March, 2024. Such development was manifested through the construction of various structures such as dams, railways, and roads which symbolize steps towards a better infrastructure.
  • Cost: The whole project, which includes the underwater metro, was part of many projects to connect things, and it cost about ₹15,400 crore. This shows that India is serious about making its transportation better and connecting cities more.

The Hooghly River Crossing

The underwater metro route, a stretch of 16.6 kilometres connecting the twin cities of Kolkata and Howrah across the Hooghly River, is located underneath the water. Out of this distance, 10.8 kilometres are underground, including the 520-meter underwater tunnel. Think of reaching 40 meters below water level which is equivalent to 12 storey building just in 5 seconds!

Construction Timeline

The project’s journey began in 2010 when the contract to build the river tunnels was awarded. Construction major Afcons formed a strategic joint venture with the Russian company Transtonnelstroy, which had prior experience building a road under the sea in Iran. The actual digging of the Hooghly tunnels commenced in April 2017 and concluded in just 67 days—a testament to efficient planning and execution.

BIM in Action

Building Information Modeling (BIM) played a pivotal role in the underwater metro’s construction. Here’s how:

  • Design and Visualization: BIM helped engineers and architects make a detailed 3D model of the whole project. This digital model made it easier for everyone involved to see and understand how the tunnels and stations would look.
  • Collaboration and Coordination: BIM helped different teams like structural engineers, MEP experts (mechanical, electrical, and plumbing), and construction managers to work together smoothly. They were able to find and fix any problems before they started building.
  • Construction Simulation: BIM simulations helped them figure out the best way to build things. The team looked at different options to decide how to dig tunnels in the safest and least disruptive way.
  • Cost Estimation and Monitoring: BIM gave precise guesses about how much everything would cost from start to finish. It also helped keep track of spending as the project went along, making sure they didn’t go over budget.

Safety and Innovation

Safety played a critical role at every stage of underwater tunnelling. The Twin-Tube excavation was planned down to the finest detail to be able to withstand water pressure and seismic forces. The employment of specific materials and reinforcement was a prerequisite for their stability.

India’s Deepest Metro Station

The deepest metro station in India is Howrah Metro Station, built on the underwater way. This metro station is 30 meters away under the ground. Its design includes safety features, effective ventilation, and emergency exits among other things.


India’s first underwater metro is not just a transportation milestone; it’s a testament to human ingenuity and collaborative efforts. As we celebrate this achievement, let’s appreciate the fusion of tradition and modernity—the traditional methods of tunnelling meeting cutting-edge technology.

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