Hong Kong escalator probe to take months as key driving gear components found ‘all broken’

Initial investigation into horrific mall incident that left 18 people injured finds ‘double mishap’ in system

PUBLISHED : Wednesday, 29 March, 2017, 12:53pm
UPDATED : Thursday, 30 March, 2017, 10:01am

A full investigation into unexplained damage found in Hong Kong’s longest escalator will take two to three months, according to government engineers probing last Saturday’s accident that left 18 people injured in one of the city’s busiest shopping malls.

A triple chain driving the 45-metre long escalator at Langham Place was broken – possibly causing it to suddenly reverse at high speed last Saturday and send terrified shoppers tumbling down. The investigation will also look into the failure of an auxiliary braking system to kick in.

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“Our initial finding is that the drive chain in the escalator was broken. The [braking] system also malfunctioned and failed to stop the escalator,” Electrical and Mechanical Services Department assistant director Eric Pang Yiu-hung said on Wednesday. “What happened was a double mishap and that’s very rare.”

Three chains forming a “triplex” connected the driving gear of the escalator with the wheels of its steps. If this triplex became ­uncoupled or loosened, a safety device should have brought the escalator to an immediate halt.

“In general, such investigations will be completed in about two to three months. We will need to take the components to a lab for materials analysis to find out the real cause of the break,” Pang said.

Escalator accident a reminder safety cannot be taken for granted

Under existing protocol, routine inspections of escalators must be conducted at least once a month and full inspections – carried out by a registered engineer – once every six months.

The last full check on the escalator was in January and the last routine check just two days before the accident. However, the scope of the routine inspection is not known, so it is unclear if the driving chain was included.

In my 33 years of experience, I can tell you this is extremely rare
Lai Wah-hing, Otis

A requirement for all contractors to inspect the 65 escalators longer than 15 metres across the city should be completed within a week, Pang said.

Yesterday, Otis, the company which built the mall’s escalator, said it would finish inspections of its long escalators “in the next three days”. A technical review of the fault involving the one at Langham Place is also underway by a special team.

“In my 33 years of experience, I can tell you this is extremely rare,” said Lai Wah-hing, Otis’ director of environment, health and safety. “I have immense confidence in our maintenance programmes and safety protocols. I can assure you that we are bringing all of our ... resources to ­address this issue.”

General Union of Lift and Escalator Employees chairman Tse King-wa identified manpower as a possible issue. He said mechanics conducted routine inspections according to contractor guidelines and it was usually not possible for them to cover every single part or component during routine checks. At times, just one worker was dispatched, limiting any heavy-duty work, he said.

Two arrested technicians suspected of interfering with probe into Hong Kong escalator accident

Otis defended two mechanics who were initially ­arrested on ­suspicion of tampering with the braking systems during an ­inspection after the incident. They were ­released on bail without any charges filed.

Otis said the workers were just “assisting in the investigation” and only at the “department’s ­request”.

“We are confident that any misunderstanding will be quickly resolved, and are working with law enforcement to clarify the ­situation,” a spokesman said.