Indonesian engineer Robert Arianto Tjandra was sentenced to one year and nine-and-a-half months in prison by a court in Singapore on Monday after the judges found him responsible for the collapse of a Pan-Island Expressway (PIE) viaduct in the city-state.

The bench found him responsible for a failure to double check calculations while building a section of the viaduct and then doing nothing to rectify the errors, as reported by Singaporean media todayonline.com.

Apart from the imprisonment, the court also ordered Robert to pay S$10,000 (US$7,328) in fines.

Robert pleaded guilty last month to three criminal charges, midway through his trial with two others — project engineer Wong Kiew Hai and project director Yee Chee Keong — as well as the project’s main contractor, Or Kim Peow (OKP) Contractors. The trial is to continue in January.

Deputy presiding judge S. Jennifer Marie said the potential for harm caused was high and that a qualified person “must exercise due diligence in ensuring the integrity of his work”, as quoted by todayonline.com.

Robert should not have been “lulled into a false sense of complacency” and neglected to check for errors, she added.

In July 2017, two of the temporary concrete structures supporting a section of the viaduct collapsed, resulting in the death of 31-year-old Chinese worker Chen Yinchuan, who was working at the site when the incident happened.

Ten other workers, who were working on the deck slab supported by the collapsing structures, also sustained injuries.

Tjandra was an employee of CPG Consultants, which was engaged by OKP and the Land Transport Authority to design and supervise the building work.

Robert’s team calculations were believed to have been behind the collapse, as some of the permanent structures were inadequate in that they would not have supported more than half of the total load they were intended to carry.

Robert was reportedly aware of his team’s lack of experience. However, he did not guide them in the proper methods at the design stage. The team came up with different and wrong effective width assumptions — of which Robert was unaware — but he did not review, check or personally prepare any design for the structures.

The Indonesian engineer later submitted the structural plans and design calculations to the Building and Construction Authority, falsely certifying he had prepared them in accordance with regulations.

The viaduct, which is about 1.8 kilometers long and made up of 50 spans divided into eight overpasses, links the PIE to the Tampines Expressway and Upper Changi Road East. It is now slated to be completed in 2022. (kuk)