Urgent repairs were causing extensive delays and cancelled services across the Sydney train network on Monday morning, which were expected to persist through the peak-hour commute.
Crews were working to repair a broken rail near Central station, in the heart of the network.
The T1 north shore and T9 northern lines were the most affected, according to the Traffic Management Centre, and were not running to normal timetables.
“Trains are delayed on both lines, but are still operating between Wynyard and Hornsby and between Hornsby and Berowra,” the centre said.
Delays were also occurring across the T2 inner west and Leppington, T3 Bankstown and T8 airport and south lines.
Passengers were advised to allow extra travel time or consider alternative transport such as the metro or local buses.