Tunnel No. 14, which links Kumrek and Khanikhola in East Sikkim, is nearly 2km long. The New Austrian Tunnelling Method was used as the tunnel was formed through the challenging geological conditions of the Lesser Himalaya.
The new rail link, between Sivok in West Bengal and Rangpo in Sikkim, is approximately 45km long and comprises 14 tunnels, 17 bridges and five stations. It cuts through mountains and valleys to connect Sikkim to the main Indian railway network for first time.
About 38km of the entire project alignment passes through tunnels – the longest is 5.27km and the shortest 538m – and around 36% of tunnelling work has been completed. All construction work on the tunnels, bridges and stations is scheduled for completion by December 2023. The project, which has been on the drawing board since 2009, was initially due to be completed this year but it has been delayed by the Covid pandemic and prolonged rainy seasons.
Last year two workers died and five were injured when prolonged rain caused a rock and mudslide during tunnelling.
