Cabinet Approves India First Underwater Rail-Cum-Road Tunnel Under Brahmaputra

Brahmaputra Tunnel Corridor: Strategic Connectivity Boost for Northeast India

The Union Cabinet has cleared a landmark infrastructure project featuring India’s first underwater rail-cum-road tunnel beneath the Brahmaputra river. The 33.7-kilometre greenfield corridor will link Gohpur (NH-15) with Numaligarh (NH-715) in Assam at an estimated cost of Rs18,662 crore. Implemented under the Engineering, Procurement and Construction (EPC) model, the project is designed to substantially enhance multimodal connectivity across the Northeast.

Project Design and Technical Features

The corridor’s core component is a 15.79-kilometre twin-tube tunnel beneath the Brahmaputra. One tube will provide rail infrastructure, while the second will accommodate a four-lane access-controlled highway. Supporting segments include a 1.26-kilometre road cut-and-cover section and a 4-kilometre rail cut-and-cover stretch.

The tunnel will drastically reduce the existing ~240-kilometre detour via the Kaliabhomora bridge route, cutting travel time from nearly six hours to a fraction of current duration.

Multimodal and Network Integration

The project connects NH-15 and NH-715 while integrating key railway lines: the Rangia–Mukongselek section near Gohpur and the Furkating–Mariani loop line near Numaligarh. It is expected to link multiple logistics, economic, tourism, and social nodes, improving accessibility to airports, railway stations, and inland waterway terminals.

Enhanced freight efficiency is projected to reduce logistics costs across Assam, Arunachal Pradesh, Nagaland, and adjoining regions.

Strategic and Economic Importance

Given the Northeast’s proximity to international borders, the corridor holds considerable strategic value. Faster mobility for civilian and defence logistics is anticipated to strengthen regional resilience and economic integration.

Employment and Developmental Impact

The project is estimated to generate nearly 80 lakh person-days of employment. It will improve connectivity to major urban centres and boost tourism flows, including access to Kaziranga National Park.

Exam-Focused Points

• India’s first underwater rail-cum-road tunnel under Brahmaputra

• Corridor Length → 33.7 km (Greenfield Project)

• Tunnel Length → 15.79 km (Twin-Tube Design)

• Mode → EPC (Engineering, Procurement & Construction)

• Cost → ₹18,662 crore

• Connectivity → NH-15, NH-715 + Rail Integration