It may sound like something out of a Cold War playbook, but India is now planning to take one of its most sensitive railway stretches deep underground.
The government has announced plans to construct underground railway tracks through the nearly 40-km-long Chicken’s Neck corridor, also known as the Siliguri Corridor in West Bengal, a move aimed at securing India’s only land link to the Northeast.
Union Minister Ashwini Vaishnaw confirmed the plan on Tuesday, underlining the strategic nature of the project.
“There is special planning for the strategic corridor connecting the northeast with the rest of the country. It is on to lay underground railway tracks and make the existing tracks four-line,” Vaishnaw told reporters.
The proposed underground rail line will run from Tin Mile Haat to Rangapani in West Bengal and will be built at a depth of 20–24 metres.
So why these two locations? Geography holds the answer. Tin Mile Haat is located in the Rangapani block of Darjeeling district, about 10 km from Siliguri, and lies close to the Bangladesh border.
Bangladesh’s Panchagarh district is just 68 km away, placing this stretch right next to one of India’s most sensitive frontiers.
Before understanding why India is going underground here, it is important to understand why the Chicken’s Neck matters so much.
Why Is the Chicken’s Neck Important?
The Chicken’s Neck is a narrow strip of land, roughly 22 km wide, that connects mainland India to its eight northeastern states. It is the only land bridge to the region and carries highways, railway lines, fuel pipelines, and critical military supply routes.
Strategically, the corridor sits at a complex junction—Bangladesh lies to the south, Nepal to the west, and China’s Chumbi Valley to the north. In the Chumbi Valley, Chinese forces enjoy significant strategic depth, making the Siliguri Corridor vulnerable to pressure from multiple directions during a crisis.
Any disruption here would not only cut off the Northeast from the rest of India but also weaken India’s military posture along its borders with China in Sikkim and Arunachal Pradesh—territories that Beijing claims as its own.
Is it Possible?
At first glance, the idea of building an underground railway beneath the Chicken’s Neck may seem unrealistic, even impossible. The region is narrow, densely used, and geopolitically sensitive, with multiple surface-level transport lines already packed into a small stretch of land.
Add to this the challenges of soft soil, high water tables, seismic activity, and the need to keep existing rail and road traffic running uninterrupted, and the project appears daunting.
However, advances in tunnelling technology, India’s growing experience in building long underground rail corridors in difficult terrain, and the strategic urgency of securing this lifeline make it not only possible but increasingly practical.
What once sounded like an extraordinary Cold War-era idea is now being treated as a realistic engineering and security solution to protect India’s most critical corridor.
How Will Underground Rail Help?
Railways are the fastest and most efficient way to move large volumes of cargo. A single freight train can carry as much as 300 trucks. At present, most infrastructure in the Chicken’s Neck corridor is on the surface, leaving it exposed to missile strikes, aerial attacks, drones, or even natural disasters.
As per reports, Defence expert Sandeep Unnithan explained why underground rail makes a critical difference.
“An underground railway section would make it safe from external attacks—air, artillery and drones. In case of a conflict, such underground corridors will ensure uninterrupted movement of troops, fuel, and essential civilian supplies,” Unnithan told India Today.
He added, “Underground infrastructure is harder to detect and resilient against first-strike scenarios. It shows a maturing of India’s tunnelling infrastructure capabilities and its capacity to undertake major projects in short timespans.”
For decades, secure connectivity through this region has been one of India’s biggest strategic weaknesses.
According to Unnithan, the Centre’s decision represents one of the fastest strategic infrastructure responses to an emerging geopolitical challenge.
Assam Chief Minister Himanta Biswa Sarma also welcomed the move, saying this “long-standing strategic vulnerability” should have been addressed soon after the creation of Bangladesh in 1971.
“The proposed underground rail link marks a major strategic breakthrough, creating a secure and foolproof transportation corridor between the North East and the rest of the country,” Sarma tweeted on X.
Why Is Underground Rail Needed Now?
Over the past decade, China has built an extensive network of all-weather infrastructure near Doklam and along Arunachal Pradesh. At the same time, political upheaval in Bangladesh has pushed bilateral ties to their lowest point in years.
In recent months, extremist voices in Bangladesh have openly threatened to cut off India’s access to the Chicken’s Neck. Adding to New Delhi’s concerns is Bangladesh’s move to redevelop the Lalmonirhat airbase in Rangpur, located close to the Siliguri Corridor.
India, however, has not stood still. The government has begun reviving a network of defunct airstrips across West Bengal, Assam, and Tripura—many dating back to World War II—to improve connectivity and operational readiness.
India has also expanded its military footprint in the region, setting up new Army bases at Chopra in West Bengal, Kishanganj in Bihar, and Lachit Borphukan in Assam. A new Navy base is planned at Haldia in West Bengal, amid China’s growing naval presence and deepening defence ties with Bangladesh.
Last year, India successfully tested an intermediate-range Agni Prime missile from a rail-based mobile launcher system for the first time. This allows missiles to be transported, concealed, and launched from anywhere across the country’s vast railway network.
Against this backdrop, the underground railway project in the Siliguri Corridor is far more than a routine infrastructure upgrade. Faced with twin pressures from a hostile China and an increasingly assertive Bangladesh, India is working to transform the Chicken’s Neck, long seen as a strategic vulnerability into a hardened and resilient spine connecting the nation to its Northeast.
