Train services on the Red Line were temporarily suspended on Friday morning after the theft of electricity wires at Rangsit Station disrupted power supply to the system.
Staff at Rangsit detected a short-circuit at 4am and later found ground wires at the electricity transformers had been cut and stolen, said Sutep Punthupeng, chief executive of the operator, SRT Electrified Train Co.
Officials had to shut down the power supply at Rangsit for repairs and later expand work to the entire line to check on transport safety, he added.
The incident forced the operator to suspend travel on the Rangsit-Lak Hok section from 5-7am and the entire route until 8.50am, he added.
The Red Line runs between Krungthep Apiwat and Rangsit. The Light Red Line to Taling Chan was unaffected by the problem.
The State Railway of Thailand subsidiary said it would accelerate a project to erect more fences to cover the whole route from next month and move all power lines underground to prevent thefts.
