Sikkim: Ambitious Sevoke-Rangpo rail project inching towards it's completion

Ambitious Sevoke - Rangpo rail project is inching towards it's completion as Tunnel No. T-11 of Sevoke-Rangpo Rail Project (SRRP), located in Kalimpong Dist., West Bengal, achieved a milestone of breakthrough on January 23. There are a total of 14 tunnels and the project will be  completed by 2024 after years of delay.  

On January 23,  commemorating the 126th birth anniversary of Netaji Subhash Chandra Bose, this achievement is dedicated to the nation. This is the sixth breakthrough of the tunnel in this project, however, in the context of the length, this is the first breakthrough of any tunnel longer than 3 km. The special event has been witnessed by Dilip Kumar Singh, Divisional Railway Manager, Smt. R Vimala, DM Kalimpong, Smt. Tshering Y Bhutia, ADM 
(LR) Kalimpong and other senior officials from Northeast Frontier Railway (NFR) in presence Mohinder Singh, Project Director and other officials of Ircon International Limited, Detail Design Consultancy team of Amberg Engineering and the construction agency ABCI Infrastructure Pvt Ltd along with officials of local administration. 

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, W.B. 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 informed Dilip Kumar Singh, Divisional Railway Manager. 

Like all other tunnels in the SRRP, to counter vulnerability of the groundmass, latest and most sophisticated tunnelling technology, i.e., New Austrian Tunnelling Method or NATM has been used here. Swiss Consultancy team of Amberg Engineering for the tunnel design has been engaged in this project and the execution team includes top class and well experienced engineers from India added Divisional Railway Manager. 

The work had been awarded to ABCI Infrastructure Pvt Ltd in September 2019, and after completion of approach roads and portal developmental work on both sides, the mining work was started on February 2020. Soon after that in March 2020, the COVID-19 pandemic broke out with subsequent lockdowns and the work hampered severely for more than six months. When the work was gaining its pace again, in October 2020, chimney formation and ‘open-to-sky’ situation occurred, due to encountering of a very low overburden zone. 

Finally in January 2021, after two and half months, the adversity was successfully tackled, and the tunnelling team moved ahead with a new spirit. Since then, there was no looking back and the result is the smooth and timely breakthrough on January 23. 
More than 4 km of tunnelling in T-11 including about 1 km of Evacuation Tunnel in only three years in spite of hurdles like COVID-19 and also poor geological conditions, is a marvellous achievement.

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 tunnelling 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 by the end of 2024. In the second phase this line will be extend till Gangtok, the capital of Sikkim and this strategically also important