India to Build Underground Railway Through Siliguri Corridor to Secure Northeast Connectivity

India has committed to constructing an underground railway line through the strategically vulnerable Siliguri Corridor, the narrow land strip connecting mainland India to its eight northeastern states. The project aims to secure vital military and civilian connectivity against potential aerial attacks, missile strikes, and geopolitical disruptions.

Union Railway Minister Ashwini Vaishnaw announced the project during Union Budget briefings in early February 2026, emphasizing the government's commitment to securing Northeast connectivity amid escalating regional tensions.

The Strategic Chokepoint

The Siliguri Corridor, commonly known as the "Chicken's Neck," is a mere 20-22 kilometers wide at its narrowest point in West Bengal. This slender strip of land serves as India's sole terrestrial link to the Northeast, home to 50 million people across eight states.

The corridor's vulnerability stems from its precarious geography—bordered by Nepal to the north, Bangladesh to the south, Bhutan to the northeast, and China's Chumbi Valley looming just 100 kilometers away.

Underground Tunnel Specifications

The proposed underground railway will run approximately 40 kilometers from Tin Mile Haat to Rangapani, constructed at a depth of 20-24 meters below the surface. This depth is specifically calculated to resist detection by satellites and radar systems while providing protection against aerial bombardment and artillery strikes.

The underground tracks will complement simultaneous upgrades to surface railway lines, which will be expanded to four tracks. Together, the surface and subsurface infrastructure will create a resilient six-line capacity ensuring uninterrupted access to the Northeast.

Why Underground?

Traditional surface railways and highways through the corridor remain exposed to multiple threat vectors. The underground alternative addresses these vulnerabilities comprehensively.

Protection Against:

• Precision missile strikes
• Drone and aerial attacks
• Artillery bombardment
• Satellite surveillance and targeting
• Natural disasters affecting surface infrastructure

The tunnel's depth ensures that even in a conflict scenario involving advanced weaponry, military supplies, troop movements, and essential civilian cargo can continue flowing to the Northeast without interruption.

Strategic Imperatives

The Siliguri Corridor carries responsibilities far beyond railway connectivity. It serves as the primary conduit for:

Military Logistics: The corridor enables Indian Army troop movements and supply chains to forward bases in Sikkim and Arunachal Pradesh, critical for maintaining defensive postures against potential Chinese incursions.

Energy Infrastructure: Oil and gas pipelines traverse the corridor, along with power grid connections linking northeastern states to the national electricity network.

Economic Lifeline: Trade with Bhutan, Nepal, and Bangladesh flows through this narrow passage, while the Act East Policy's ambitions for Southeast Asian connectivity depend on secure northeastern access.

Highway Network: National highways running through the corridor provide the only road link for goods and passenger movement to the region.

Historical Context and Recent Triggers

The corridor's vulnerability has been exposed repeatedly. The 2017 Doklam standoff between Indian and Chinese forces near the Bhutan-China-India tri-junction demonstrated how quickly tensions could escalate in the region.

More recently, Bangladesh interim government Chief Adviser Muhammad Yunus's remarks describing northeastern India's "landlocked" status and characterizing Bangladesh as the region's "only guardian of the ocean" have heightened concerns in New Delhi.

These statements, combined with threats from certain Bangladeshi political figures about "separating the Northeast," have underscored the urgency of hardening the corridor against potential coercion or disruption.

Deterrence Through Infrastructure

Military strategists view the underground railway as a passive deterrence measure. By demonstrating that India can maintain Northeast connectivity even under attack, the project signals to potential adversaries that attempts to strangle the corridor would prove futile.

China has invested heavily in similar infrastructure hardening along its borders, including underground facilities in Tibet. India's underground railway represents a comparable approach to protecting strategic assets without escalatory military deployments.

Implementation Challenges

Constructing a 40-kilometer underground railway through the corridor presents significant engineering challenges. The region's geology, high water table in certain areas, and seismic activity will require advanced tunneling technology and careful planning.

The project will likely employ tunnel boring machines similar to those used in urban metro rail construction, though adapted for the longer distances and strategic requirements of this corridor.

A New Era of Strategic Infrastructure

The Siliguri Corridor underground railway represents a broader shift in India's approach to infrastructure development—viewing connectivity projects not merely as economic enablers but as strategic assets requiring protection against 21st-century threats.

As regional dynamics evolve and India's northeastern states become increasingly important for Act East Policy implementation, securing the only land link to this region takes on paramount importance.

The project, once completed, will stand as a testament to India's commitment to maintaining territorial integrity and ensuring that 50 million northeastern citizens remain permanently connected to the mainland—regardless of what challenges may emerge along the Chicken's Neck.