A senior railway official on Friday (April 12) announced that mining work has been completed in 10 out of 14 tunnels of the Sivok-Rangpo Rail Project (SRRP). The Railways has also established a new target deadline of August 2025 for the completion of the project.

Once finished, this project will mark the first-ever rail connection between Sikkim and the rest of the country. Spanning a total length of 44.96 km from Sivok in West Bengal to Rangpo in Sikkim, the project includes 14 tunnels, 22 bridges (13 major and 9 minor), and five railway stations: Sivok, Riyang, Teesta Bazar, Melli, and Rangpo. 

Currently, trains traveling towards Guwahati from other regions pass through Sivok railway station, paving the way for a new rail route to Rangpo in Sikkim via Riyang, Teesta, and Melli (all in West Bengal). 

Railway line distribution across tunnels and bridges

Among the project’s milestones, 10 tunnels have seen completion of mining work, with four tunnels already lined, ranging from 538 meters to 5.3 km in length. “Out of the 14 tunnels, mining work has been completed in 10. Out of the 10, we have completed the lining work in four tunnels with work going on in the rest six. The longest tunnel is 5.3 km and the shortest one 538 metres,” the official said.

He added, “Out of 13 major bridges, 12 are ready with the substructure. The maximum height of the pier (of Bridge-17) is 85 metre, constructing which was itself an uphill task. The most demanding aspect of the project is that 86 per cent of the total rail line passes through tunnels and five percent over bridges. Only nine percent is under the open sky.” 

Challenges in meeting August 2025 deadline

Talking about the challenge in meeting the August 2025 deadline, an official from Ircon International, which is constructing the whole project, said, “We experienced significant squeezing/deformation in T-8 and T-10 due to the very poor strata of rocks. We took remedial measures to control it by cement consolidation, grouting and increased primary support as per the design.” 

“To address this issue, several other corrective measures had been taken. However, progress has been slow, due to challenging rock conditions. To address this challenge, project engineers have adopted specialized support methods.,” he added.

“We will start laying rail tracks from the end of May from Tunnel 14 which falls in Rangpo,” the Ircon official said.

Teesta Bazar station almost complete 

Project authorities have reported that the Teesta Bazar station, poised to become the nation’s inaugural underground railway station, is nearing its final stages of completion. Additionally, despite grappling with formidable geological challenges and rugged terrain, the SRRP team has maintained consistent progress. However, communication disruptions along NH-10 between Sivok and Rangpo, resulting from a flash flood on October 4, 2023, have significantly affected the advancement of tunnel, bridge, and yard construction works.

Originally sanctioned in 2009-10, delays in land acquisition and forest clearances, exacerbated by the COVID-19 pandemic, slowed progress. However, with all tenders awarded and works in progress, the project is on track despite the revised cost. “The initial cost of the project was Rs 4,085 crores (estimate 2015) but the revised cost is Rs 12,132.95 crores approximately,” the Ircon official said.