Syllabus: GS –III & V: Infrastructure, Transport 

Why in the News?

The Cabinet Committee on Economic Affairs has approved the construction of India’s first underwater twin-tube road-cum-rail tunnel beneath the Brahmaputra River in Assam.

• The project will connect Biswanath’s Gohpur on NH-15 (North Bank) and Golaghat’s Numaligarh on NH-715 (South Bank)  through a 33.7 km access-controlled corridor. 
• at a cost of ₹18,662 crore.
• Once completed, it will become the first underwater road-rail tunnel in India and the second in the world, after the Fehmarnbelt link between Germany and Denmark.

Key Features of the Project

• The 33.7-km corridor will include a 15.79 km twin-tube tunnel and 17.91 km of approach roads (10.15 km on Gohpur side and 7.76 km on Numaligarh side).
• The twin-tube tunnel will be constructed using Tunnel Boring Machine (TBM) technology beneath the Brahmaputra River.
• The tunnel will be located approximately 57 metres below the riverbed, ensuring safety and structural stability.
• It will provide road connectivity, while one of the tunnel tubes will also accommodate railway infrastructure, enabling multimodal transport.
• The twin-tube structure will consist of two separate tubes, each designed for a two-lane highway. 
• One of the tubes will also have a rail-cum-road facility, with the railway line embedded within the roadway. 
• In normal times, the tunnel will operate as a four-lane road. 
• During exigencies, one tube will facilitate railway operations, converting it into a two-lane road with one railway line. Cross passages will be provided at every 500 metres for safety. 
• The project will be developed under the Engineering, Procurement and Construction (EPC) mode, where the contractor handles design, construction, and delivery.
• The construction cost is estimated at Rs 11,982.36 crore, while the total capital cost stands at Rs 18,662.02 crore. 
  • The cost will be shared between the Ministry of Road Transport & Highways and the Ministry of Defence in an 80:20 ratio. 
  • The Government of Assam will bear 50 % of the SGST on the construction cost, amounting to around Rs 539 crore.
• Major implementing and stakeholder agencies include:
  • National Highways and Infrastructure Development Corporation Limited
  • Indian Railways
  • Government of Assam
  • Indian Army (due to strategic importance)

Strategic and Economic Importance

1. Transforming Connectivity in Northeast India

• The tunnel will reduce the travel distance between Gohpur and Numaligarh from 240 km to just 34 km.
• Travel time will reduce drastically from 6 hours to about 20 minutes.
• It will enhance connectivity between Assam, Arunachal Pradesh, Nagaland, and other northeastern states.

2. Boost to Trade, Tourism, and Economy

• The corridor will connect industrial hubs, logistic nodes, railway stations, airports, and inland waterways, improving freight efficiency.
• It will strengthen access to important economic and tourist centres such as:
  • Kaziranga National Park
  • Numaligarh industrial area
  • Tezpur and Itanagar
• It will generate approximately 80 lakh person-days of employment, boosting local livelihoods.

3. Strategic and National Security Importance

• The project has major defence significance, enabling faster troop and equipment movement near India’s sensitive eastern borders.
• It aligns with India’s broader vision of strengthening border infrastructure and national security preparedness.

Important Terms Explained

• Twin-Tube Tunnel: Two parallel tunnels, ensuring safety, traffic separation, and efficient transportation.
• Tunnel Boring Machine (TBM): A specialised machine used for constructing tunnels underground safely and efficiently.
• Access-Controlled Corridor: A highway where entry and exit are regulated, ensuring high-speed and safe travel.
• Engineering, Procurement and Construction (EPC): A project model where a contractor manages the entire project lifecycle.
• Multimodal Integration: Connecting different modes of transport such as road, rail, air, and waterways for seamless mobility.

Link with Government Vision and Policies

• Supports the Government’s focus on infrastructure-led growth under the National Infrastructure Pipeline.
• Aligns with the broader development goals of Act East Policy, improving connectivity with Southeast Asia.
• Strengthens integration of the Northeast with the rest of India, fulfilling the vision of balanced regional development.

Challenges and Considerations

• High construction cost and technical complexity due to seismic activity in Assam.
• Environmental sensitivity of the Brahmaputra ecosystem.
• Need for proper disaster-resilient and sustainable infrastructure design.

Conclusion

The underwater twin-tube road-cum-rail tunnel under the Brahmaputra represents a historic engineering achievement and a symbol of India’s growing infrastructure capacity. Beyond improving connectivity, it will strengthen economic growth, national security, and regional integration, transforming Assam and the Northeast into a major gateway for development and strategic progress.

Exam Hook

Key Takeaways

• First underwater road-rail tunnel in India.
• Located under Brahmaputra River connecting Gohpur and Numaligarh.
• Developed under EPC mode at ₹18,662 crore.
• Strategic importance for connectivity, defence, and economic growth.

Mains Question

Discuss the strategic, economic, and regional development significance of underwater tunnel infrastructure projects in India, with special reference to the Brahmaputra tunnel project.

One-line wrap:
India’s first underwater Brahmaputra tunnel marks a transformative leap in connectivity, national security, and infrastructure development in the Northeast.

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