India’s first underwater twin-tube Road-cum-Rail tunnel in Assam: Here’s how this project could transform Northeast connectivity

Gohpur-Numaligarh tunnel project: The Cabinet Committee on Economic Affairs (CCEA) has approved the construction of the country’s first underwater twin tube road-cum-rail tunnel project. The new infrastructure project will be developed at an estimated cost of Rs 18,662 crore. ## India first underwater twin tube tunnel project While the underwater twin tube road-cum-rail tunnel will be located in Assam, its impact will extend beyond the state, enhancing connectivity for Arunachal Pradesh, Nagaland and other Northeast region. Gohpur-Numaligarh tunnel project: Length The total length of India’s first underwater twin tube road-cum-rail tunnel project will be 34 km. The project will feature two parallel tunnels, designed to facilitate smooth and high-capacity movement of both road and rail traffic. ## Construction details The project involves the construction of a 4-lane access-controlled greenfield connectivity corridor from Gohpur on NH-15 to Numaligarh on NH-715, including a 15.79-km road-cum-rail tunnel beneath the Brahmaputra River. The project will be executed under the Engineering, Procurement and Construction (EPC) mode. Once completed, it will become India’s first underwater road-cum-rail tunnel and the second such tunnel in the world. “The project alignment integrates with 02 major National Highways (NH-15 and NH-715) and 02 Railway lines i.e. Rangia-Mukongselek Railway Section under Rangia Division of NFR on Gohpur Side and Furkating-Mariani loop line section under Tinsukia Division of NFR on Numaligarh side. The project providing seamless connectivity to key economic, social, and logistics nodes across Assam. Additionally, the project will enhance multi-modal integration by connecting with 11 Economic Nodes, 03 Social Nodes, 02 Tourist nodes and 08 Logistic Nodes, providing enhanced connectivity with 04 Major Railway Station, 02 Airport, and 2 inland water way thereby facilitating faster movement of goods and passengers across the region,” the Ministry of Railways said. The construction of the project is expected to be completed in five years. ## Significance Upon completion, the underwater twin tunnel project in Assam will reduce the distance between Gohpur and Numaligarh from 240 km to just 34 km and cut travel time from around 6 hours to just 20 minutes. At present, connectivity between Numaligarh on NH-715 and Gohpur on NH-15 spans around 240 km via the existing Kaliabhomora road bridge near Silghat on NH-52. The journey takes nearly six hours, passing through Numaligarh, Kaziranga National Park, and Biswanath town. The project is also expected to double the average travel speed. It will provide high-speed connectivity to Assam and Arunachal Pradesh. ## Boost tourism, economy in Northeast Beyond connectivity, this mega infrastructure project is expected to boost tourism in the Northeast, improve border connectivity and facilitate cross-border trade, strengthening economic and strategic linkages in the region. It will enhance the efficiency of freight movement and reduce logistics cost. ## Employment generation The project will also generate approximately 80 Lakhs person-days of direct and indirect employment, and will open new avenues of growth, development and prosperity in surrounding regions. ### India's First Underwater Twin-Tube Road-cum-Rail Tunnel: Assam Feature | Details Project Name | Construction of Twin Tube TBM road Underwater tunnel 2 Lane each under River Brahmaputra along with provision of Railway infrastructure in one of the tubes, in the state of Assam on EPC Mode with total length of project as 33.7 Km. Corridor | Gohpur on NH-15 – Numaligarh on NH-715 Length (km) | 33.7 Km. Total Civil Cost (Rs Cr.) | 11,982.36 Cr. Land Acquisition Cost (Rs Cr.) | 716.65 Total Capital Cost (Rs Cr.) | 18,662.02 Mode | Engineering Procurement Construction (EPC). Project Length | Instant Project of Length 33.77 Km. Twin Tube TBM Tunnel with Railway in one of the tubes | 15.79 Km. Total Road cut & cover | 1.26 Km. Total Rail cut & cover | 4 Km. Major Roads Connected | National Highways – NH-15 & NH715 Rail Line connected | Rangia-Mukongselek Railway Section under Rangia Division of NFR on Gohpur SideFurkating-Mariani loop line section under Tinsukia Division of NFR on Numaligarh side Economic / Social / Transport Nodes Connected | Airports (02): Dony Paulo Holongi Airport Itanagar and Tezpur AirportRailway Stations (04): Numaligarh Railway Station, Gohpur Railway Station, Golaghat Town Railway Station, Simaluguri JunctionInland Water way Terminals (02): Biswanath Ghat Water way terminal, Tezpur Water way terminalEconomic Nodes (11): Numaligarh Industrial Area, Jorhat DIC, IIDC Titabor, Industrial Area Junakinagar, Industrial Estate Nagaon, IIDC Demow, Industrial Estate Sivasagar, IIDC Naltali, Industrial Area Dolabari, Mini Industrial Area Biswanath, MMLP Jogighopa.Social Nodes (03): 1 Tribal district – Dima Hasao; 02 Aspirations Districts-Udalguri & DarrangTourist Nodes (02): Kaziranga National Park & Deopahar Archaeological Site Major Cities / Towns Connected | Numaligarh, Tezpur, Gohpur Dibrugarh in Assam & Itanagar In Arunachal Pradesh Employment Generation Potential | 80 Lakhs Man-Days of Direct & In-direct Annual Average Daily Traffic (AADT) in FY-25 | Estimated at 4680 Passenger Car Units (PCU) Anish Mondal is a journalist with over nine years of experience covering the railways and roadways. Currently a member of the Indianexpress.com editorial team, Anish specializes in high-impact sectors. Professional Journey Anish began his career at the public broadcaster Rajya Sabha Television (now Sansad TV), where he developed a foundational understanding of legislative processes and national governance. In 2018, he transitioned to digital financial journalism at FinancialExpress.com, spending nearly six years refining his expertise in market trends and corporate reporting. Before joining The Indian Express in 2025, he served as a key contributor at ETNowNews.com. Education & Expertise Anish’s reporting is backed by a rigorous academic background in communication and the humanities: Master of Journalism and Mass Communication (MJMC) – Apeejay Stya University Post Graduate Diploma in Journalism and Production (PGTVRJP) – Apeejay Institute of Mass Communication Bachelor of Arts (English Honours) – University of Calcutta Areas of Coverage Connectivity: Detailed reporting on the expansion of Indian Railways and National Highway networks. ... Read More