A citywide safety test of escalators and travolators ordered by the Beijing bureau of quality and technical supervision after Tuesday's accident at Beijing Zoo Station on Line 4 is a much needed safety overhaul of the expanding subway network.

An ascending escalator at the subway station suddenly started moving in the opposite direction on Tuesday morning, causing the death of a 13-year-old boy and leaving 30 people injured. The OTIS escalator was reportedly still in the guarantee period, and maintenance staff had conducted a routine check on June 22.

Initial investigations by Beijing's quality authorities showed the accident was caused by a malfunctioning component that suddenly loosened the drive chain and the failure of its protection mechanism to prevent the escalator from moving in the reverse direction. At a news briefing on Wednesday evening, a deputy director of the bureau said the "initial conclusion" is that there "are design and manufacturing faults" in the OTIS 513 MPE-type escalator installed at the zoo station.

The Beijing municipal transport commission has suspended the use of all 257 escalators of this make in the capital until after detailed safety checks. And the General Administration of Quality Supervision, Inspection and Quarantine has ordered that all such escalators across the country be put out of use and overhauled.

These responses, no doubt, are swift and necessary but far from enough to mitigate people's safety concerns in subways in Beijing and other big cities. The irony is that subways have become too important a mode of transport for commuters to stop using them. Commuters' helplessness, however, should not stop the authorities from getting to the root of the problems and solving them.

Some media reports say that commuters who used the fateful escalator at the Beijing Zoo Station had complained of "overheated" handrails before the accident. The problem persisted even after inspections by OTIS mechanics.

Therefore, it is important that investigators pinpoint the causes of the accident - whether it was a technical fault, whether relevant department officials failed to see the accident coming or whether they ignored potential risks, or all of these.

Beijing's quality authorities' initial conclusion that there are design and manufacturing defects in OTIS 513 MPE-type escalators should by no means become an excuse for us to point the finger only at the manufacturer. If the escalators were defective, why didn't the quality authorities discover them earlier? Why did they wait until the accident?

This is the second accident involving an OTIS escalator in less than seven months. On Dec 14, 24 people were injured at a subway station in Shenzhen when an escalator suddenly reversed.

The two accidents should be a warning for city authorities to make subway safety their top priority and lay down a set of strict codes for technological standards.

(China Daily 07/09/2011 page5)