Crucial modifications to Dreamworld's Thunder River Rapids ride were never approved by Workplace Health and Safety officers, an inquest into the death of four tourists has been told.
With no consultation, theme park staff removed slats from the conveyor belt and made structural alterations to the attraction that had been installed more than 30 years ago.
WPHS chief safety engineer Michael Chan said his department had no record of the alterations and they had made the ride "even more hazardous".
"You have introduced a hazard," he said on Tuesday.
"What they have done is introduce a nip point where you can be trapped and dragged in ... if you remove two slats, you have introduced a hazard and altered the health and safety of the ride."
The inquest into the October 2016 deaths of Cindy Low, Kate Goodchild, her brother Luke Dorsett and his partner Roozi Araghi on the Thunder River Rapids ride was told that two months before the accident, Dreamworld's senior safety officers tried to bypass an annual engineering inspection.
Mr Chan said he met with the park's general manager of engineering Chris Deaves and head of safety Angus Hutchings on August 14, 2016.
The pair told Mr Chan they had been unable to secure a registered engineer to perform a safety audit as part of the registration process.
"They proposed that the department accept the maintenance regime in lieu of an annual inspection by a professional engineer," Mr Chan said.
"I explained that such a proposal was unacceptable," Mr Chan said.
Dreamworld subsequently was granted two extensions to obtain the annual audit before a final deadline of December 1, 2016 when WPHS threatened the ride would be shut down.
WPHS director of licensing and advisory services Johanna Sutherland told the inquest the extensions were "unprecedented".
"It was first time (WPHS) had granted an extension ... there were no policies in place to allow the extension," Ms Sutherland said.
She said the decision to allow the ride to continue operating "concerned" her, but ultimately the decision was made by Mr Chan.
He told the inquest he believed the delay "would not introduce significant risks" to Dreamworld's continued operation.
However, Mr Chan said the fatal incident at Dreamworld "highlighted, to me at least, that we (Workplace Health and Safety) need to do more".
He said the department was considering changes to the inspection process which would require theme parks to present an "argument" outlining their safety and maintenance regime.
"It is then the department's role to go and verify if it is running the way they claim it is running. So it is going the next step," Mr Chan said.
WPHS officers are the focus of the sixth week of the inquest.
Australian Associated Press
