27°C | Light rain
Jul 7, 2011
Investigations into the sudden reversal of an escalator at a train station on Beijing Subway's Line 4 that killed one person and injured 30 others on Tuesday were continuing yesterday as suspicion centred on a broken bolt.
Li Lianghua , safety inspector at Beijing's Quality and Technical Supervision Bureau, told The Beijing News investigators had found a broken bolt at a joint that fixed the main drive chain to the floor.
It was the same fault that caused an escalator at Shenzhen Metro's Guomao station to reverse direction in December last year, injuring 24 people. Both escalators were made by Otis.
Some escalator experts said the central government should be blamed for the frequent reversal of escalators on the mainland, rather than the bolt or Otis, because operators were not required to install heavy-duty models in busy public areas.
Zhang Lexiang , deputy secretary general of the China Elevator Association, said operators of transport hubs such as airports and subway stations were free to buy any escalator they deemed fit.
"The lack of regulation leads to a very bad result. It helps the cheapest model win the bid," Zhang said.
He said it cost at least three times more to manufacture a proven heavy-duty model suitable for use in a public transport hub than a light-duty commercial model meant for a shopping mall. The extra money went into reinforcing the motor, power transmission system and the escalator's supporting framework.
"Ordinary citizens cannot tell the difference between light-duty and heavy-duty models," he said. "They probably won't feel anything even if they ride escalators every day.
"But any government knows the difference. Only in [mainland] China can they turn a blind eye to this."
Zhang said he was impressed by the high quality standards that the Hong Kong government demanded for escalators in public facilities, especially the amount of metal required to make gearwheels, which was several times more than that used in escalators commonly found in mainland subway stations.
A bureau official confirmed yesterday that there was no law or national regulation mandating the use of heavy-duty escalators at transport hubs. The authorities began drafting a law on the safety of special equipment in 2009, but it was not known when that process would be completed, he said.
The Beijing municipal government issued a regulation mandating the use of heavy-duty escalators at transport hubs in July last year, but the authorities had no plan to upgrade or replace existi<52>ng light-duty escalators in such areas, the official said.
The escalators on Line 4 were not subject to the new regulation because they had been installed more than a year earlier.
According to the bureau's website, Beijing has more than 14,000 escalators and moving walkways. After Tuesday's accident, the bureau ordered subway companies to station security staff at both ends of every escalator to limit passenger flow during public holidays and rush hours.
US-based Otis, the world's biggest escalator manufacturer, divides its escalator products into two categories - commercial and heavy-duty - in international markets such as Hong Kong. But its subsidiaries on the mainland make no such distinction for sales there.
A very popular model, the XO508 produced by Xizi Otis, the company's biggest mainland subsidiary in Hangzhou , Zhejiang , could be and had been used in almost all kinds of location, according to the company's website.
The escalator was suitable for recreation centres, shopping malls, office buildings and transport hubs, it said. It had been "successfully" used in a train station in Beijing, an office building in Hainan and a museum in Henan province.
Otis apologised to the victims of Tuesday's accident, but declined to release the details of the model of escalator involved in the incident or its specifications.
binglin.chen@scmp.com Copyright (c) 2011. South China Morning Post Publishers Ltd. All rights reserved.