Train services were hit for nearly eight hours on the Chennai-Gummidipoondi route after a goods train derailed near Athipattu early on Thursday.
As many as 10 express trains, including the Chennai Central-Jammu Tawi Andaman Express, Chennai Central-Ahmedabad Navjeevan Express and Bangalore-Guwahati Express, were diverted through Gudur, Renigunta and Arakkkonam.
The Chennai Central-Howrah Coromandal Express (12842) scheduled to start from Central station at 8.45 am was rescheduled to 2 pm because of the late running of the pair train.
The Jan Shatabdi Express connecting Chennai with Vijayawada was cancelled in both directions.
Southern Railway officials said three wagons of the goods train bound to Kazhakootam near Thiruvananthapuram from Madikudi in Andhra Pradesh derailed around 1 am when the locomotive was near Pudhu Nagar station on the Chennai-Gummidipoondi route.
Rail workers led by DRM S. Anantharaman restored service in the line towards New Delhi around 8.45 am while operations resumed in the line towards Chennai four hours later.
The cancellation of the Jan Shatabdi Express hit hundreds of people such as Ram Prasad of Vijayawada. Radhika Chandramouli rued she would miss most of her cousins wedding reception.
The derailment also affected EMU services on the Chennai-Gummidipoondi stretch with the first unit leaving Moor Market Complex only at 8.25 pm. Services in the opposite direction was restored at 12.25 pm.