SINGAPORE — Defective manufacturing of a crane was what caused it to collapse and kill two foreign workers at the National Art Gallery construction site last year, a coroner’s court has ruled.

Delivering his findings today (Dec 9), State Coroner Marvin Bay ruled out foul play and pointed to “bores that did not comply with design specifications” as the cause of the accident on Sept 30 last year.

A crane, which was lifting an excavator, had collapsed at about 10.50am that morning, sending metal parts and concrete counterweights flying.

Thai national Somkhot Chanyut, 49, was crushed to death by the crane’s hook assembly, which also amputated his left shoulder and dislocated his left leg.

Bangladeshi Ronju Ahmed, 28, was killed by one of the counterweights. His body was pinned between mangled scaffolds on the fifth storey, and had to be brought down by the Singapore Civil Defence Force using rescue ropes.

Four other workers also sustained injuries from the falling debris and three were hospitalised.

The court heard that Mr Ismail Sias, who was operating the defective crane that day, was duly qualified and had performed the necessary checks before he commenced work that morning. For instance, he ensured that the 5,000kg excavator was well within the crane’s lifting capacity of 15,080kg.

According to Mr Ismail, the crane boom started to shake when the excavator was hoisted up well above the building. Sensing something amiss, he pressed the emergency button to stop the crane, but to no avail. Seconds later, he saw the boom plummet.

Calling this a “tragic industrial accident”, Mr Bay said the bores, which were 0.33 to 1.28mm larger than the standard diameters, resulted in an “excessively loose fit” between the pulley and the bearings. The Ministry of Manpower’s investigations found that this had caused the wire-rope to be caught in the sheave and eventually snap.