SINGAPORE - An engineer who failed to go through the detailed plans and design calculations for permanent corbels, or support structures, of the Pan-Island Expressway viaduct near Upper Changi was sentenced to six months' jail on Thursday (July 4).
Leong Sow Hon's offence was discovered after a portion of the incomplete viaduct gave way on July 14, 2017.
The collapse resulted in the death of 31-year-old Chinese worker Chen Yinchuan. Ten other workers were injured in the incident.
An investigation found that the permanent structures used in the viaduct's construction were so inadequate, they could have collapsed under the weight of a full traffic load, causing a large number of casualties.
Leong, 61, who is also the managing director of Calibre Consulting Singapore, had been appointed by the Land Transport Authority as an accredited checker.
On June 24, he pleaded guilty to failing to check the detailed structural plans and design calculations in accordance with regulations under the Building Control Act.
One count of falsely certifying that he had carried out the required checks was considered during sentencing.
Deputy Public Prosecutor Yang Ziliang said that Leong's offences could have resulted in "high potential harm".
The DPP told District Judge Hamidah Ibrahim: "Investigations have revealed that the permanent corbels were inadequately designed... Out of the 10 permanent corbels, eight of them were inadequately designed for the total load, including traffic, upon completion of the viaduct."
Of the eight, five of the corbels were unable to support the weight they were supposed to be designed for. The remaining three would have shown significant cracks with a full traffic load, leading to a collapse.
DPP Yang added: "If the viaduct collapsed after it had been constructed and opened to traffic, the casualties caused would be unimaginable."
Leong is so far the only person involved in the case to plead guilty. As the final checker, Leong's job was to go through the detailed plans and design calculations for the permanent corbels.
However, no calculations were performed for both permanent and temporary corbels during the submissions stage of building works.
On Thursday, the court heard that Leong intends to appeal against his sentence and was offered bail of $15,000.
The cases involving the main contractor, Or Kim Peow Contractors, and four other men allegedly linked to the incident are still pending.
They are: the qualified person from subcontractor CPG Consultants, Robert Arianto Tjandra, 46; project engineer Wong Kiew Hai, 31; and project director Allen Yee, 49 - both from Or Kim Peow Contractors - as well as its group managing director Or Toh Wat, 51.
Or Kim Peow Contractors has been replaced by Hwa Seng Builder, which clinched the deal to complete the stalled project for $95.6 million last year.
The viaduct was supposed to be completed by the first quarter of next year, but is now expected to be ready by the first half of 2022.