Jurong Shipyard was fined $230,000 by the Ministry of Manpower (MOM) yesterday for failing to ensure a cherry picker was maintained and safe to use for accessing work at heights.

The failure resulted in the aerial platform buckling and collapsing. Two workers in it fell 30m to the bottom of a dry dock on Oct 29, 2011, and died.

Jurong Shipyard had been engaged to perform repair works on a vessel in its shipyard at 29, Tanjong Kling Road.

It had engaged Shipblast Marine, the employer of the two workers, for grit blasting work, which is what they were carrying out at the front of the vessel, inside the cherry picker.

An MOM investigation found the cherry picker had undergone an 18-month overhaul maintenance work from April 23, 2011 to July 18, 2011.

Corrosion was found on all four boom sections and basket. The problems were rectified by blasting and painting over the affected areas.

However, one of the sections had sustained significant wear and had been worn down to a thickness of 2.86mm, from 6mm originally. According to the manufacturer's guidelines, the section should have been replaced.

But Jurong Shipyard did not refer to the manufacturer's inspection guidelines prior to the incident, MOM found.

Instead, it referred erroneously to the American Bureau of Shipping rules for survey after construction, which is meant for conventional vessels and not for lifting equipment. Thus it did not replace the section in question.

In its statement yesterday, MOM said Jurong Shipyard had also failed to establish and conduct comprehensive checks on all the sections of the boom of the cherry picker following the overhaul maintenance.

Defects within the unextended boom sections that had led to the fatal accident were not detected as a consequence.

MOM director of occupational safety and health inspectorate Chan Yew Kwong said: "Jurong Shipyard failed to take the necessary precautions to ensure the safe use of its equipment.

It should have referred to the manufacturer's inspection guidelines to check for corrosion and cracks and conduct thorough equipment checks to ensure the safety of its workers.

"Two workers lost their lives as a result of poor equipment maintenance. The MOM will prosecute owners of equipment who fail to provide for its safe use, putting workers' lives at risk."

The shipyard was fined under the Workplace Safety and Health Act.