Northeast Frontier (NF) Railway has achieved a major milestone in the second phase of the Dimapur- Kohima new Broad Gauge Line connectivity project following the breakthrough of tunnel no. 4 between Molvom-Pherima station. In a press release, NF railway chief public relations officer (CPRO) Sabyasachi De informed that the tunnel measuring 1319 meters in length including 151 meters cut and cover got done on January 24, 2024.
Stating that it was the second longest tunnel in phase-II of the project, the CPRO said that this achievement was considered a major step ahead for connecting Kohima with rest of the nation through Indian Railways network.
The construction of the tunnel started from portal–1 side on March 10, 2021 and the work from portal-2 started on January 23, 2023.
NF railway informed that the rock strata encountered was mainly shale and extremely weathered in nature with seepage of water present at few locations, inside the tunnel.
To construct the tunnel, the railways had to face a lot of problems as continuous rains since April, 2022 and extremely poor quality of soil in Tunnel no. 4 led to squeezing and sliding at portal-2 affecting the progress.
CPRO said that guidance from the Geological Survey of India and independent consultant were sought to solve the problems.
The average rate of underground excavation was 41.25 meters per month. The underground excavation work was executed by using New Austrian Tunneling Method (NATM) and by deploying 210 numbers of manpower round the clock since the starting of the tunnel.
With the final breakthrough of tunnel, CPRO said the underground excavation of 1168 meters has been completed. Final lining of the tunnel was targeted for completion in May 2024, De informed.
The total length of project is 82.5 km (2.75 Km in Assam and 79.75 Km in Nagaland) having eight new stations viz Dhansiri, Dhansiripar, Shokhuvi, Molvom, Pherima, Piphema, Menguzuma and Zubza.
The project includes 24 major bridges, 156 minor bridges, six Road Over Bridges, 15 Road Under Bridges and 21 Tunnels of 31 km length.
The total anticipated cost of the project is Rs. 6,663 crore.
The new rail connectivity project when completed would also help in transportation of food grains, automobiles and other infrastructural and construction items to the hilly state at a much cheaper cost from other parts of the country benefitting local people.