Incompatibility of its signaling systems caused MTR’s October debacle

The MTR’s signal failure, which led to simultaneous breakdown of four metro lines on Oct 16 in Hong Kong, was caused by an incompatibility between two signaling systems used in the metro lines concerned, MTR officials explained on Wednesday.

Calling the incident “unprecedented”, MTR officials said the company would be fined HK$8 million for causing around six hours of travel chaos on the Island Line, Tsuen Wan Line, Kwun Tong Line and Tseung Kwan O Line. The amount will be given back to MTR passengers in the form of fare discounts later in 2019.

Meeting with the media, MTR officials said a review report on the signal accident had already been submitted to the government.

According to the report, the root cause of the signal failure was inconsistencies in software settings of the two signaling systems. The MTR said the signaling systems were provided by two different suppliers — Siemens and Alstom.

Alstom, which has been applied to the Kwun Tong, Island and Tsuen Wan lines since 1996, could be reset automatically while Siemens, used in Tseung Kwan O Line and part of the Kwun Tong Line since 2001, needed a manual reset.

The MTR operators and other staff were unaware of these inconsistencies, as well as their potential impact on the workings of the signal systems before the failure occurred on Oct 16, the report noted.

The city’s sole railway operator denied the incident had anything to do with the signal replacement project and testing — nor was it a result of a computer virus or sabotage.

MTR officials did not give a direct response when asked whether human negligence was involved. They just said it was an unforeseeable situation — which had not been clearly described by the two suppliers in the Operation and Maintenance Manuals.

The MTR will also work out more effective contingency plans to safely evacuate and redirect passengers if there are any future disruptions.

“Our goal is to avoid similar accidents happening again in the future when new signal systems need to be integrated”, said Adi Lau Tin-shing, operations director of MTR Corporation.

The signal malfunction on Oct 16 caused train delays lasting from 61 to 114 minutes, forcing commuters to use other forms of transport — mainly public buses. This in turn led to packed vehicles and longer-than-usual waiting times along highway routes.

Our goal is to avoid similar accidents happening again in the future when new signal systems need to be integrated.” Adi Lau Tin-shing, operations director of MTR Corporation