An inquest is examining the Dreamworld accident that caused the deaths of (clockwise from top left) Cindy Low, Roozi Araghi, Luke Dorsett and Kate Goodchild.Dreamworld’s former engineering boss has questioned whether a single emergency stop button should have been installed onto a ride that later killed four people.
成都桑拿

Cindy Low, Kate Goodchild, her brother Luke Dorsett and his partner Roozi Araghi died in October 2016 when a water pump on the Thunder River Rapids failed.

It caused water levels to drop and their raft to flip after colliding with another raft that became stuck.

Bob Tan, former general manager of engineering at the Gold Coast tourist attraction, on Thursday told an inquest into their deaths that shutting down the ride could have caused a bigger hazard.

He told coroner James McDougall putting a stop to the ride would have also turned off a water pump that would have led to dangerous amounts of water then washing through the ride.

“If two pumps turned off at the same time, there is violent water turbulence back flowing into the reservoir at the area at the bottom of the conveyor,” he said.

“I would not be comfortable to agree to doing that.”

The inquest has previously heard experts suggested a single emergency stop button be fitted during safety audits, but it could not be done because the attraction was too old to be retro-fitted.

Prior to the tragedy, Mr Tan was made aware the now defunct Wonderland theme park in Sydney had fitted a similar pump to their version of the ride.

But he did not consider making similar adjustments to the Dreamworld ride because it was built differently.

The long-running inquest has previously heard that the water pump had malfunctioned on October 19, 22, 23 and twice in the hours before the October 25 tragedy.

None of those failures were investigated.

Mr Tan, affectionately known among Dreamworld staff as the “oracle” because of the 28 years he’d worked at the park, also overlooked major modifications to the ride as posing a safety risk.

He said the removal of slats from the ride’s conveyor belt took place before he started working at the park and so didn’t see an issue with the changes.

“I was not involved in removing them but I assumed whatever had to be done was done,” he said.

“Nobody reported they had a concern, so I didn’t do what I didn’t know.”

Mr Tan, who resigned from Dreamworld in 2016, presumed safety analysis was carried out before the slats were removed but never found proof that it had been.

The inquest has previously heard the removal of the slats from the conveyor belt introduced a hazard, but Mr Tan assumed it complied with basic engineering and safety standards.

The inquest has wrapped up until December 6, when three expert witnesses will give evidence.