Guwahati, Jul 23 (PTI) The Northeast Frontier Railway (NFR) has carried out several track renewal works to enhance the safety, and speed of trains and provide comfortable travel to passengers.Continuous progress towards renewal of the railway track is being carried out and 27.66 km of plain tracks have been deep screened by cleaning impervious layers of dust, and sand ash in June this year, an official of the NFR said here.A total of 91.62 km of track renewal works have been done up from April to June this year and the maintenance of tracks at regular intervals has resulted in smooth operations of trains.Moreover, 1,758.15 km of tracks have been tested by USFD (Ultra Sonic Flaw Detection) machine in June this year.The USFD technique is carried out to detect flaws like cracks and timely removal of defective rails for safety. PTI DG MM MM