Features Construction In October 2009, the foundation stone for construction was laid by the vice president of India. In May 2010, IRCON was awarded the contract for construction. to August 2025 in May 2024, to December 2027 in January 2025.
Wildlife and environmental approval The line traverses through
Mahananda Wildlife Sanctuary in the foothills of
Kangchenjunga mountain range of
Himalayas, Darjeeling Forest Division, Kurseong Forest Division, Kalimpong Forest Division of West Bengal and Pakyong District Forest Division of Sikkim, runs parallel to
Teesta River and crosses
Rangpo River. It connects villages and towns, such as the
Kalijhora, Birik daara, Lohapul,
Rambi Bazar, Gailkhola,
Teesta Bazaar, Chitrey, Melli, Kirnay, Tarkhola, Chanatar,
Rangpo and Khanikhola,
Majitar, Rangpo. By 2013, the route alignment was not finalised due to lack of wildlife and environmental approval as the first 22 km through the forested elephant sanctuary. In February 2013, the railways made a proposal to the environment and forest ministry that railway will install elephant sensors along the stretch of the proposed railway line in Mahananda elephant sanctuary or run the trains at a speed of only 20 km per hour in the forest area and stop when an elephant is sighted close to the track. Delays caused the cost overruns, compared to the original year 2008 estimates of Rs.13.4 billion. In February 2016,
Supreme Court of India approved the project with strict guidelines of the National Wildlife Board which had cleared the project in June 2015, but ordered restricted speed, wireless animal tracking sensors and allowed digging of tunnels only during daytime. ==Extensions and spurs==