Hong Kong MTR

Unknown signalling system problem caused Hong Kong’s October MTR chaos, operator says

  • Firm hit with an HK$8 million penalty for service delays that left rail network in chaos
  • Penalty to be given back to passengers in form of fare concessions late next year, says MTR boss
PUBLISHED : Wednesday, 19 December, 2018, 5:00pm
UPDATED : Wednesday, 19 December, 2018, 11:25pm

Hong Kong’s rail operator will be hit with an HK$8 million (US$1.02 million) penalty for service delays in October that saw an unprecedented simultaneous breakdown of four MTR lines.

The operator on Wednesday submitted a final report on the shutdown to the government in which it said a previously unknown incompatibility between two signalling systems caused the chaos.

The MTR Corporation said it had been unaware of the operational differences between two interconnected groups of computers controlling the systems, which were supplied by Siemens and Alstom.

Alstom’s system involved 25 computers for different sections of the network, in place since 1996 on the Kwun Tong, Island and Tsuen Wan lines. These were able to automatically reset themselves when necessary. But the system by Siemens, in place since 2001, involved eight computers on the Tseung Kwan O line and part of the Kwun Tong line, and needed resetting manually.

Both systems required resetting after about 20 years of operation. On October 16 the Alstom system automatically reset while the Siemens system continued functioning.

“This resulted … in an endless loop causing corresponding instability in all 25 Alstom sector computers,” the report said.

“The possible impact on train services was not known to the operators and maintenance staff, nor was it explicitly described in the operation and maintenance manuals.”

MTR operations director Adi Lau Tin-shing dismissed any suggestion of negligence on the part of railway staff, saying the MTR had never been told by the suppliers of the resetting requirements.

An investigation into the disruption was carried out by a panel formed by the rail operator’s senior management and three external experts, including Michael Hamlyn and Bruce MacDougall from the Institution of Railway Signal Engineers.

Lau said a penalty of HK$8 million would be imposed on the firm for the train service delays, which ranged in length from 61 minutes to 114 minutes.

Hong Kong MTR signal fault finally fixed after six hours of commuter chaos

“The disruption will be treated as four separate cases of delays, and a total of HK$8 million will be incurred,” Lau said. “The amount will be given in the form of fare concessions for passengers in the later half of next year.”

The rail giant is fined for delays at a rate of HK$1 million per incident if a disruption lasts between 31 minutes and an hour. A delay of between one and two hours incurs a penalty of HK$2 million.

October’s shutdown affected the Island, Tsuen Wan, Kwun Tong and Tseung Kwan O lines. Six hours of commuter turmoil followed, with sections of the network paralysed.

The MTR has since been subjected to a barrage of criticism and mounting calls for officials to impose harsher penalties on the firm for service outages.

The operator has ruled out the cause of the disruption having anything to do with upgrades to the signalling systems, which involve tests every night on various lines after services end for the day.

But with the separate signalling systems from different suppliers, the network relies on synchronised data transmission at all times to function properly.

There was no evidence the incident was related to a computer virus or sabotage, the firm said.

Lau said the signalling systems for other lines on the network had been checked or reset to avoid a repeat of the system failure.

But lawmaker Michael Tien Puk-sun said the MTR needed to put in place preventive measures to avoid a reoccurrence.

“I think it was a design flaw. This was an unprecedented problem for the MTR and it’s understandable,” he said. “But if it happens again a second time then it won’t be easily forgiven.”