News Desk
MUMBAI — On a humid Saturday morning, anticipation filled the air at the edge of Sanjay Gandhi National Park. Engineers, officials, and onlookers watched as “Shivaji,” India’s largest urban tunnel-boring machine, was carefully lowered into a 42-metre-deep shaft—a moment marking the beginning of a transformative journey for Mumbai’s commuters.
The Thane-Borivali Link Road project, an ambitious 11.84-kilometre twin-tunnel drive, promises to revolutionise travel between the city’s eastern and western suburbs. What is now a gruelling 60 to 120-minute drive through congested roads will soon become a swift 15-minute passage, thanks to this feat of modern engineering.
The Mumbai Metropolitan Region Development Authority, overseeing the $1.6 billion project, highlights its ecological sensitivity. By tunnelling beneath the park’s forested hills, planners aim to preserve the surface environment, avoiding the need to widen existing roads and protecting thousands of trees. “This is engineering in the service of ecology,” said SVR Srinivas, the authority’s metropolitan commissioner, celebrating the project’s innovative approach.
The technical challenges are formidable. The twin tubes, each with three lanes and an emergency shoulder, must navigate steep gradients and volcanic rock. Contractors from Herrenknecht and the Indian-Afcons consortium deployed advanced lifting systems to position the machine, demonstrating the precision and expertise driving the project.
Once operational, Shivaji will carve through Mumbai’s bedrock at a steady pace, laying the foundation for a parallel tube to follow.
The tunnels are designed to carry 120,000 vehicles daily, easing pressure on the city’s famously overcrowded rail network and providing a vital new artery for millions of residents.
Mumbai’s embrace of underground infrastructure reflects a broader vision for the city’s future. With land at a premium, planners are looking below the surface to expand capacity and improve connectivity. At least eight major underground projects are underway or planned, including coastal road extensions and new metro lines, signalling a new era of urban development.
As Shivaji disappeared into the earth, cheers erupted from the assembled crowd—a testament to the optimism and pride surrounding this landmark project. For Mumbai, the tunnels represent not just a shortcut, but a leap forward in sustainable, forward-thinking infrastructure.
The tunnel boring machine (TBM) used in Mumbai’s Thane-Borivali Link Road project, “Shivaji,” represents the pinnacle of large-scale urban infrastructure engineering in India. With a diameter exceeding 13 metres and the capacity to carve multi-lane tunnels through hard volcanic rock, it is designed to handle the city’s challenging geology and deliver high-capacity roadways beneath sensitive ecological zones—all while minimising surface disruption.
In contrast, Elon Musk’s Boring Company has developed the “Prufrock” series of TBMs, which focus on speed, automation, and cost efficiency. Prufrock machines are smaller in diameter (around 3.6 metres), optimised for rapid, single-lane tunnels, and feature innovations like surface launches and fully remote operation. While Mumbai’s TBM is tailored for massive, high-traffic urban corridors, Musk’s machines are designed for quick deployment and scalable urban mobility solutions. Both approaches showcase cutting-edge tunnelling technology, but each is optimised for different urban challenges and visions for the future of underground infrastructure.
