The Northeast Frontier Railway is conducting the surveys of two mountain rail routes to extend train services to Nathu-la in Sikkim, senior officials said on Wednesday.

“The survey to connect Rangpo to Gangtok will be complete by March 2023 to identify the alignment and locations of probable stations. It is in the final stage. Also, the preliminary survey for the Gangtok-Nathu-la stretch will finish by April next year,” said Sabyasachi De, the chief public relations officer of the NFR.

That there is an urgency to lay railway tracks along these two stretches was evident as Anshul Gupta, the general manager of the NFR, held a meeting with Sikkim chief minister P.S. Tamang on Wednesday.

At the meeting, they discussed issues like land acquisition along the probable alignment that needs to be carried out before the project starts.

Over the past few years, and particularly after the Doklam standoff of 2017, the central government has put impetus to include Sikkim, the Himalayan state that sits on the India-China border, on the Indian railway map.

“Work is on in full swing between Sevoke (around 20km from here) and Rangpo. There is a plan to finish the work by December next year. Meanwhile, the survey reports of the stretch between Rangpo and Nathu-la via Gangtok will be prepared and submitted to the railway and defence ministries. Once the projects are approved, work will start in these two stretches,” said a railway official.

Sikkim’s capital Gangtok is 38km away from Rangpo by road. Nathu-la, which is further north, is 53km away from Gangtok.

Railway officials, engineers and others after a breakthrough in tunnel 12 on December 24 Picture courtesy Northeast Frontier Railway

NFR general manager Gupta, sources said, also inspected the ongoing work along the Sevoke-Rangpo route on Tuesday while on his way to Sikkim.

The rail route that will connect Rangpo town of Sikkim that sits on the Sikkim-Bengal border is 45km long.

“We have to build 14 tunnels, 17 bridges and five stations along the route,” said a railway official.

According to the official, the total length of the tunnels will be 38.65km of which tunnel mining work has been completed in around 25km.

“On December 24, a breakthrough was achieved in tunnel 12, which is the fifth main tunnel of the project,” he added.

The tunnel, NFR sources said, is 1.4km long. It is located between Tarkhola and Shukia Khola in Kalimpong district of Bengal.