SINGAPORE - A Keppel Shipyard worker died from multiple injuries after being struck by a falling rudder of an oil tanker in March last year as he was fitting it on.

A coroner's inquiry heard that the 59-tonne rudder had dislodged after the shackle, which connects the rudder to the ship and had a capacity of 35 tonnes, fractured from the 24-tonne overload.

Mr Mandeep Kumar, 36, was doing repair works on the tanker City of Shanghai at Keppel Shipyard when the rudder dislodged and hit him, knocking him off balance.

He clung onto part of the ship 7.3m above the ground, but fell off when the falling rudder crashed into him and severed his right arm.

The impact sent the Indian national into cardiac arrest and he was pronounced dead at the scene.

Another worker, Mr Miah Md Masum, was also hit by the rudder but did not suffer serious injuries.

The Ministry of Manpower's investigations found that senior foreman Inbaraj Vellu had forgotten to factor in the weight of the additional components that had to be attached to the rudder, which he calculated to be 32 tonnes.

No checks were done to ensure the accuracy of Mr Inbaraj's calculations.

Keppel Shipyard found that Mr Mandeep should not have been standing on part of the rudder while working.

He should have operated from the scaffolding erected beside the rudder or from a hydraulic crane, a Keppel investigator said. He also did not secure his safety belt to an anchor point.

On Friday (March 19), State Coroner Marvin Bay ruled Mr Mandeep's death as a "tragic industrial misadventure".

The coroner said the incident underscores "the need for stakeholders in heavy industries to understand and prepare for the risks inherent to their industries".

"These would include undertaking appropriate risk assessments and verifying the safety and fitness for use of all equipment. The assessments should also ensure that workers are not placed in positions where they would vulnerable to injury in the event of any machinery or component failure" he added.

Social enterprise ItsRainingRaincoats, which focuses on migrant worker issues, said in a Facebook post in March last year that Mr Mandeep had worked in Singapore for 12 years and was a father of two young children.

MOM is contemplating taking enforcement actions against the parties involved under the Workplace Safety and Health Act.