A portion of the main tunnel on the 111-km under-construction Banihal-Katra railway link in Jammu and Kashmir was completed on Saturday, an official said. Tunnel T-49B is 12.6 km long and the longest tunnel of Indian Railways. It is part of the Udhampur-Srinagar-Baramulla Railway Line (USBRL) project. The portion that was completed on Saturday is between Kundan Adit and Arpinchala in Khari Tehsil, the company undertaking the project construction said.