An operator at the controls of the Thunder River Rapids Ride did not know two emergency stop buttons had two dramatically different stopping times, an inquest into the Dreamworld tragedy has been told.
The ride operator pressed the slower stop button to try to halt the conveyor carrying the ill-fated raft with its six passengers, but that did not work.
The raft struck another that had blocked its way, causing it to flip. Four of the occupants were killed.
It was revealed yesterday that two children who were also on the ride remained secured in the raft by seatbelts and were not thrown clear, despite media being told at the time by a police spokesman that they ended up in the water and were pulled to safety.
Ride operator Peter Nemeth, who could operate nearly every ride in the theme park, made the shocking revelation about the emergency buttons yesterday on the second day of the inquest into the Dreamworld disaster of October 25, 2016, which killed tourists Kate Goodchild, Roozi Araghi, Luke Dorsett and former Kawerau woman Cindy Low.
The inquest in the Southport Coroners Court has been told there were two buttons which stopped the conveyor belt — one on the main control panel Nemeth was operating, which took about eight seconds to stop.
The second was about 12m away near junior ride operator Courtney Williams, which was able to stop the ride in two seconds. Williams had been trained in operating the ride the morning of the tragedy and, the inquest has heard, did not know what the button did and was told not to worry about it.
Nemeth said he was one of the top 10 ride operators and had been working at the park since 2012. Under questioning from Matthew Hickey, barrister for Ms Low's family, Nemeth said he had not been aware of the halt time difference between the two buttons.
Hickey asked: "If you had known the emergency stop button near Courtney Williams (stopped the conveyor faster) you would have been prepared to move to that place to stop the conveyor more quickly?"
Nemeth: "Yes."
Hickey: "But you didn't do that because you didn't know that was possible?"
Nemeth: "Yes, that is correct."
The inquest was also told by forensic crash investigator Senior Constable Steven Cornish that judging by when the conveyor stopped, the slower stop button – which would take eight seconds to bring the Thunder River Rapids Ride conveyor to a halt – was pressed 10 seconds after the incident. The fast stop button near Williams was never pressed.
Under cross examination, Sen-Const Cornish was asked whether the tragedy would have been avoided if the fast stop button had been pressed.
"It would not have avoided it," Sen-Const Cornish said. "It may have limited some injuries. Possibly."
In the days before the accident, staff had been discouraged from using the fast stop button near where Williams was standing.
"The e-stop situated at the unload platform must only be pressed in the event the main control panel cannot be reached," a staff memo read. Nemeth told the inquiry yesterday he had pressed the slower stop button on the main control panel before the rafts collided after noticing water levels dropping.
The tragedy occurred after a pump referred to as the "south pump'' failed, causing water levels to drop significantly and beaching one raft on top of the conveyor belt.
"I do remember seeing the second raft," Nemeth said. "I saw the second raft coming over the conveyor belt."
Nemeth said at that stage there was between five and 10 metres between two rafts. He said he pressed the slow stop button, which would stop the conveyor belt within eight seconds.
"It didn't stop even though I pressed it two or three times," Nemeth said. The control panel at Dreamworld came under fire in the first two days of the inquest.
A second raft carrying passengers then hit the stuck raft and flipped, throwing four of the occupants out.