MTR reveals cause of East Rail Line disruption

A faulty pantograph – which is used to collect power through contact with the overhead cable – caused the cable to snap, triggering a short circuit, investigators found

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The MTR train service between Hung Hom and Kowloon Tong was suspended due to a tripped circuit breaker for one of the line’s overhead cables. Photo: David Wong

Published: 3:50pm, 31 May 2017Updated: 9:36pm, 31 May 2017

A power failure two weeks ago that disrupted services along the East Rail Line for four and a half hours was caused by a damaged device on an MTR train’s roof, it was revealed on Wednesday.

The service disruption on May 18 along the East Rail Line left thousands of passengers stranded and scrambling for alternative transport during the evening rush hour.

The overhead cable between Hung Hom and Mong Kok East suddenly snapped and collapsed at around 3pm, knocking out power and bringing a train to a sudden halt 400 metres from Mong Kok East station. Some 110 passengers had to get out and walk along tracks to the nearest platform.

A faulty British-made pantograph – which is used to collect power through contact with the overhead cable – caused the cable between Hung Hom and Mong Kok East to snap, triggering a short circuit when the train was travelling towards Mong Kok East, according to an MTR Corporation paper submitted to the Legislative Council’s subcommittee on railway matters.

MTR passengers left stranded at Kowloon Tong station after the outage. Photo: David Wong

The railway operator said that according to its preliminary investigation, the pantograph was found damaged before it caused the cable breakage that knocked out power.

“Our preliminary investigation showed the incident was caused by the damaged pantograph breaking the cable. The whole incident had nothing to do with the cable itself,” it said.