Sydney Trains entire network is experiencing delays, after a communications issue struck shortly before the afternoon peak. The meltdown meant no services were running for over an hour, and, even after some resumed, commuters were warned to make other arrangements. See how the major incident unfolded. The network was brought down by an issue with the radio system that signallers and train controllers use to stay in contact with train crews. Transport for NSW said all trains had to be halted for safety reasons until the system could be rebooted. Although trains did begin running about an hour and fifteen minutes later this was at a reduced frequency.