Infrastructure Lockdown gives time for Mumbai's busy rail network maintenance Updated : April 22, 2020 11:29 AM IST About 210 km of track and 1,250 critical welds were tested by ultrasonic flaw detectors. This period is being utilised to enhance safety of train operations and maintenance works. Subscribe to Moneycontrol PRO at just Rs.33/- per month for the first year. Use code SUPERPRO. Limited period offer. Available on Web and Android.