The deaths of four people on a ride at Dreamworld in October 2016 would have been prevented by the installation of a water level sensor during safety upgrade works months before.
An inquest into the deaths of Cindy Low, Kate Goodchild, her brother Luke Dorsett and his partner Roozi Araghi has been shown an expert’s report of the tragedy.
They died when a water pump on the Thunder River Rapids ride malfunctioned, resulting into two rafts colliding and flipping.
The inquest at Southport Coroners Court has already heard reduced water levels, due to the failed pump, contributed significantly to the tragedy.
On Monday, the inquest was shown a safety audit by Safety Related Control Systems that concluded the lack of a water level sensor on the ride was the “primary cause” of the incident.
The inquest heard Dreamworld had commissioned Products for Industry (PFI) to undertake a safety upgrade on the 30-year-old ride.
The upgrade, completed in February 2016 with some additional works in March, cost about $19,000.
It did not include the installation of a water level sensor, which was being investigated for a second stage of the upgrade.
The second stage was never given a start date before the tragedy.
“The primary cause of the tragic incident was the lack of a suitable safety-rated water level detection system interfaced to the upgraded conveyor system,” the report concludes.
Such a safety system could easily have been provided and at a minimal cost.”
The report says if a water level sensor had been installed at the same time as the other upgrades in February and March it would have cost between $2000-$3000.
PFI electrical engineer Matthew Sullivan agreed when asked if it would have been possible to install a water sensor on the ride.
The manufacturers of the drive that powered the water pump were unable to recreate the fault following the incident, the inquest heard.
Danfoss Australia’s technical and engineering manager Eduardo Gie attended Dreamworld on November 2, 2016 to determine what was causing the south pump on the ride to fail.
Despite multiple tests, Mr Gie and others were unable to determine the cause of the fault.
The inquest also heard the pump’s drive, which was installed in 2006, had a recommended operating life of 10 years.
The inquest continues.