Atal Setu, Sikkim

Atal Setu Bridge is a two-lane road bridge on National Highway 10 at Rangpo, Pakyong district, Sikkim. It spans across the deep Rangpo River valley and connecting Sikkim with West Bengal. The Atal Setu project comprises a viaduct and its approach roads, with a total length of about 1.123 km (including approach roads. The main viaduct portion is 826m in length. It was constructed by the National Highways and Infrastructure Development Corporation Limited (NHIDCL) at a cost of approximately ₹133.49 crore. The bridge was officially inaugurated on 4 November 2022 by President of India, Droupadi Murmu. Inauguration of the Atal Setu was part of a series of development project unveilings by the President in Sikkim during her visit. The bridge improves the travel along NH-10 by bypassing older, narrower road alignments in Rangpo. The 14.8-metre-wide deck accommodates safe two-way traffic flow and pedestrian paths. Since it is designed as a viaduct, its deck is supported on piers erected in the valley, allowing it to traverse rugged terrain with minimal grade changes. The viaduct is constructed from Prestressed concrete segments to withstand Sikkim’s harsh environment (including heavy monsoon rains and seismic activity). It has 18 modular spans that are bonded together for strength and flexibility. The continuous-span design and robust construction meet Indian highway standards for seismic Zone V (since Sikkim lies in the high-seismic Himalayas), ensuring the bridge’s earthquake resistance. Overall, Atal Setu is among the longest roadway bridges in the state and is often referred to locally as the Rangpo Viaduct (sometimes “Rangpo IBM Bridge”).