Dreamworld's Thunder River Rapids had broken down twice on the same day a raft on the ride flipped over, killing four people, a coronial inquest on the Gold Coast has been told.
New Zealand woman Cindy Low, inset, was one of four victims who died after an accident at the Dreamworld theme park in Australia. Photo: AFP / Facebook
New Zealand woman Cindy Low, Kate Goodchild, her brother Luke Dorsett and his partner Roozi Araghi were killed instantly from crushing injuries, when their six-person raft collided with an empty vessel and flipped backwards in 2016.
Two children who were also on board the same raft managed to escape.
Detective Sergeant Nicola Brown told the inquest that if an automatic system had been put in place to stop the ride when water levels dropped too far, the deaths could have been prevented.
It also heard a young ride operator on the Thunder River Rapids did not know there was an emergency stop button within reach.
Investigators told the inquest that the ride staff had 57 seconds to identify a raft was trapped on a conveyor belt before a second raft, carrying the victims, hit it and flipped.
The ride could have been stopped in two seconds.
The inquest heard there was no drill training for staff at Dreamworld to determine how they would react in an emergency situation.
The Thunder River Ride also had no device to monitor water levels or automatically shut ride down if levels fell, it was the role of the ride operators.
The ride was modified in 1980s and 90s and the number of long slats on the conveyor belt was reduced, leaving a gap which allowed a raft to get caught and flip.
'Nobody uses the emergency stop button'
When interviewed by police, the young operator at the unload area said she had been told not to worry about the emergency stop button because nobody used it.
Detective Sergeant Brown said an emergency stop button at the unload area was designed to halt the conveyor within two seconds.
She told the inquest a large pump on the Thunder River Rapids ride had failed at both 11:50am and 1:09pm without any incidents.
"Engineering attended, reset the pumps and operating continued as per normal," she said.
Detective Sergeant Brown said two operators managed the ride and that there was a stop button on the main control panel.
"It's not an emergency stop, it's a slow stop. It takes approximately seven seconds," she said.
Detective Sergeant Brown said the young ride operator closest to the incident had to signal to an operator at the control room, which cost crucial seconds.
In his opening address to the inquest, counsel assisting the inquiry Ken Fleming QC described the tragedy as "a significant mechanical breakdown".
The coroner heard that in 2001 one of the ride's rafts flipped during the 'dry run' at the start of the day and no-one was on board.
Mr Fleming said the 2001 incident was so serious it prompted a staff member at the time to write in an email: "I shudder when I think if there had been guests on the ride."
He said past incidents and previous breakdowns of the ride would be explored and investigated during the inquest.
Inquest to examine 'gravely emotional' issues
Mr Fleming told the inquest the fatalities in 2016 happened on "what was one of, if not the most, popular ride built as suitable and safe for the whole family".
"The south pump failed causing a massive drop in the water," he said.
"As the water dropped, one boat became caught on rails."
Answering questions from Mr Fleming, Detective Sergeant Brown said there was no switch to automatically shut down the Thunder River Rapids if water levels dropped too much.
Mr Fleming: "Was there any device fitted anywhere that would monitor the water levels that you could see?"
Detective Sergeant Brown: "No."
Mr Fleming: "Was there any device which could automatically switch the whole of the ride off if water levels dropped?"
Detective Sergeant Brown: "No."
Mr Fleming: "The only way it could be done is by operator intervention?"
Detective Sergeant Brown: "That's right."
The court heard the victims were "forcibly propelled", hitting the stationary raft.
Mr Fleming told the inquest the Dreamworld tragedy "has been felt Australia-wide".
He told the coroners court issues "gravely emotional" to the families of those killed would be explored at the inquest.
"It will be difficult for them throughout the inquiry," he said.
He said 37 witnesses would be called to give evidence at the inquest over two weeks.
- ABC