Ultrasonic testing of Rails & Welds on loop lines ( B- Scan Digital Ultrasonic Flaw Detectors equipped with 9 channels for Rails & A- Scan Digital Ultrasonic Flaw Detectors for welds ) by Need Based Concept method under traffic conditions through outsourcing and reporting the same as per Indian Railway Standard Specification for Ultrasonic testing of Rails and Welds ( Revised- 2020 ) read with latest correction slip & Comprehensive instructions of USFD testing of Rails and Welds on outsourcing and Manual for Ultrasonic testing of rails and welds ( Revised 2022 ) read with latest correction slips with contractor ' s own B- scan 9 channel & A- scan machines and operators in Khurda Road, Sambalpur & Waltair divisions of East Coast Railway.