Carrying out through USFD testing of running Rails & Welds (excluding flange testing) including level crossings, lead portion of points and crossings and scabbed rail testing of all types of Rails by NBC (Need based concept) method under traffic conditions as per provisions of IR's "USFD manual & Specifications for Ultrasonic Testing of Rails and Welds" with latest correction slips & related instructions, duly marking defects, submission of daily reports and storing back up data as specified & directed with Contractor's USFD machine. NOTE: The SRT/DRT machine should have minimum of 9 probes B scan (including 37 degree forward/backward probe for detecting bolt hole cracks) with Contractors USFD machine.