A former MTR engineer said on Thursday the railway operator should update its equipment to prevent a repeat of the service disruption that happened a day ago.

Train services between Sheung Wan and Quarry Bay stations were halted for over an hour during the disruption on Wednesday, when an obstruction was found in the railway track area near Wan Chai station during the morning peak hour.

MTR Corporation will carry out a full probe and submit a report to the Transport and Logistics Bureau within a month.

Gary Zhang, a former lawmaker who is now director of the Smart Transportation Alliance, told RTHK that he believed the incident was not caused by an external object but by an extension of a rail milling vehicle that had not been retracted, which might have resulted in damage to equipment alongside the track.

"If the probe finds out that there is negligence, staff training would and should be the focus of the probe," he said.

"Also in regards to upgrades of the railway infrastructure, many of the new-generation signalling systems – or the overall design – tend to put fewer items alongside the track.

"Equipment pieces are usually kept to a minimum alongside the track, or it's best if there is none at all. This reduces risks."

Zhang said that while it was possible that the disruption might have occurred as a result of equipment components coming loose due to wear and tear, that possibility was less likely to have been the case.

Ben Chan, who chairs the transport panel in the Legislative Council, suggested the railway operator carry out large-scale maintenance earlier than usual during long holidays or periods that tend to see less passengers.

That, he said, is because workers usually have only around three hours to carry out such work in the dead of night after MTR services end.

Services at Hung Hom station had, Chan pointed out, ended in advance before to allow maintenance work to be carried out.

The panel has, he said, decided to set up a subcommittee on matters relating to railways to follow up on the disruption.