Tunnel no. T-11 of the Sivok – Rangpo Rail Project (SRRP), located in Kalimpong District of West Bengal, achieved a major milestone of breakthrough on 23rd January. This is the sixth breakthrough of tunnels in this project. However, in the context of the length, this is the first breakthrough of any tunnel longer than 3 km.
The length of the Main Tunnel is 3205 m and of Evacuation Tunnel is 960 m, located in between Tarkhola and Tumlangkhola in Kalimpong district of West Bengal. The Evacuation Tunnel connecting the NH-10 and the Main Tunnel No. 11 was completed in December 2022. The Main Tunnel traverses through vulnerable and challenging geological and seismic conditions of the Lesser Himalaya. Like all other tunnels in the SRRP, to counter vulnerability of the groundmass, latest and most sophisticated tunneling technology.
New Austrian Tunneling Method or NATM has been used here. A Swiss Consultancy team has been engaged for the tunnel design in this project and the execution team includes top class and well experienced engineers from India.
The mining work in the tunnel was started on February 2020 after completion of approach roads and portal developmental work on both sides.
This new rail link project connecting Sevoke (West Bengal) and Rangpo (Sikkim) is about 45 kms long and is characterised by 14 nos. tunnels, 22 nos. bridges and 5 nos. stations. About 38 kms of the entire project alignment is passing through tunnels and it is to mention that 67% of mining work has already been completed. This is one of the prestigious ongoing National projects in India and on completion of this project, first time the State of Sikkim will be connected via railways. At present all the activities related to construction of tunnels, bridges and station yards are going on war footing basis to complete the project at the earliest.
