Lift safety: Reliability issue should be a priority

A repair notice pasted on a lift in Ang Mo Kio Street 31, after it suddenly shot up 17 floors and trapped an Indonesian maid for 90 minutes on March 7.
A repair notice pasted on a lift in Ang Mo Kio Street 31, after it suddenly shot up 17 floors and trapped an Indonesian maid for 90 minutes on March 7. PHOTO: ST FILE

As a former engineer, I strongly believe in reliable products that demonstrate their value through longevity.

But with rapid advances in many modern technological fields and a growing culture of "use and throw away", manufacturers and consumers have come to accept short product life cycles and planned obsolescence for devices such as phones and laptops.

However, for other equipment - air conditioners, refrigerators, escalators and lifts, for instance - it is reasonable to expect better quality and long-term reliability.

The importance of having reliable industrial equipment is best illustrated by the recent spate of lift malfunctions in Housing Board blocks ("Probe into case of lift that shot up 17 floors"; last Thursday).

Reliability is the cornerstone of safe operation. Shoddy build quality, improper installation, poor maintenance or carelessness can and will lead to fatal accidents.

In the case of lifts, it is highly disconcerting that the safety devices intended to protect users failed to function as intended.

Such safety devices can be classified as soft limits or hard limits. The former refers to programmed limitations built into the operating software, such as a tele-monitoring system, or implements, such as an infrared sensor.

Should soft limits fail, hard limits can take over, shutting down the equipment as a last resort, through means such as a kill switch.

Both types are designed and tested to rigorous standards.

The Building and Construction Authority should, therefore, investigate whether these safety features were properly installed, properly maintained with a reliable human monitoring system and in good working condition at the time of the incidents.

Moreover, to prevent further mishaps, it is imperative that consumers and manufacturers change their mindsets.

Reliability should be accorded foremost priority when deciding on designs and purchases, and safe operating parameters must be strictly adhered to.

The margin for error is slim and the price of failure too high.

Paul Chan Poh Hoi

A version of this article appeared in the print edition of The Straits Times on March 16, 2016, with the headline 'Lift safety: Reliability issue should be a priority'. Print Edition | Subscribe