Dreamworld inquest told the rafts involved each experienced multiple problems within the last two months before tragedy

THE two rafts involved in the Thunder River Rapids ride had been experiencing problems in the month prior to the tragedy which killed four people, the inquest has heard.

THE two rafts involved in the Thunder River Rapids ride had been experiencing problems in the month prior to the tragedy which killed four people.

One raft had experienced four problems and the other three problems between October 6 and 23, 2016.

The problems were noted on daily sign out sheets completed by the maintenance team each morning.

Dreamworld engineering Wayne Cox, who reviewed the maintenance sheets, said no one was collating the sheets for trends.

Asked what he would have done if he had known about the trends.

“I would have taken the rafts out,” he said.

The day after the tragedy at Dreamworld where four people were killed. Picture: NIGEL HALLETT

The inquest has also been shown an email sent the morning of the incident, trying to organise a technician.

When told it would take two days for a technician to get to the park to look at the pump, engineering supervisor Scott Ritchie replied: “We will see what unfolds.”

The pump broke down three times the day of the incident.

Mr Cox, who was on duty the day of the incident, said he was only aware of the first pump breakdown in the morning.

He said he was not aware if a technician had been organised to look at the pump.

Members of the general public arrive to pay their respects. Picture by Scott Fletcher

The inquest also heard that Dreamworld engineers should not have just reset the south pump after it registered an earth fault.

Twice on the morning of the disaster Dreamworld electricians had been called to an earth fault.

Both times the electricians reset the pump without investigating what the root cause of the fault was.

Applied Electro Services electrical technician Michael Takac, who serviced the pumps, said the pumps should “definitely not” simply have been reset after the earth faults.

Police officers at Dreamworld. Picture: NIGEL HALLETT

“You would have to go down this path to find out the root cause,” Mr Takac said.

Prior to the tragedy, the experienced electrician said he had been called to investigate the cause of the earth faults which had been plaguing the ride for the week prior to the incident.

Mr Takac was booked to visit the park two days after the incident.

He said it would be concerning if an earth fault was being repeatedly registered.

“Because you don’t know what it is related to. An earth fault is a pretty hard one to find … it could be more parts in the drive … without trying parts or further testing, it’s a random one … they are a bit of a hard one to find,” Mr Takac said.

He said in the event of an earth fault it is usual procedure to “get digging deeper” to find out what had happened.

Coroner James McDougall on the scene of the Dreamworld ride tragedy. Pics Adam Head

Earlier, the inquest heard that the cost of installing a water level monitoring system on the Thunder River Rapids Ride would have been “minimal”, according to an expert report.

A report by Safety Related Control Systems shows that if installed at same time as safety upgrades to the ride in February 2016 it would have cost between $2000 to $3000.

“The PRIMARY cause of the tragic incident was the lack of suitable safety rated water level detection system interfaced to the conveyor system. As detailed above such a safety system could easily have been provided at a minimal cost,” the report said.

The report said the sensors would have prevented the incident.

“ … had such a water level detection system been in place it would have brought the conveyor to a safe stop as soon as the water had fallen to a crucial level thereby likely avoiding a collision,” the report said.

Police on the scene of the Thunder River Rapids ride tragedy. Picture: Adam Head

Products for Industry (PFi) engineer Matthew Sullivan, who completed the February 2016 upgrades, said installing the sensors would have been possible.

He said Dreamworld never asked. Ride operators instead used an algae mark on the wall of the water trough to check if water levels were dropping or not.

PFi had previously installed water level sensors on Dreamworld’s Log Ride.

The inquest into the Dreamworld tragedy continues.

The inquest is examining what happened about 2pm on October 25, 2016 when a pump stopped working on the Thunder River Rapids Ride, causing water levels to drop and a raft to become stuck on the conveyor belt.

That raft was hit by another carrying Luke Dorsett, his sister Kate Goodchild, her daughter Ebony, 12, Roozbeh Araghi, Cindy Low and her son, Kieran, 10.

The four adults were killed. The children escaped uninjured.

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Mr Sullivan told the inquest he was asked to design and install a new safety system on the Thunder River Rapids Ride in October 2015.

Stage two of that work was to include measures which would control and monitor the pumping system.

Mr Sullivan said the first stage of the upgrades were completed in early 2016 but the pump work was not done.

Floral tributes left on the front lawn of Dreamworld for the victims. Picture: Tim Marsden

“I don’t recall any discussions of stage two,” he said.

Stage one, which cost more than $19,000, included work to stop rafts slipping back on the conveyor, monitoring if rafts were getting stuck at the bottom of the conveyor, chain break sensors and upgrades to the emergency stop buttons.

Mr Sullivan said he was qualified in conducting risk assessments on rides.

“If we were asked to,” he said.

Mr Sullivan said PFi was never asked to do a risk assessment.

The company was also asked to install water level monitors on the Log Ride at the park.

Dreamworld never asked to install similar water level sensors for the Thunder River Rapids Ride.

The inquest was also told the pumps on the Thunder River Rapids Ride were coming to the end of their recommended life span when the disaster which killed four people occurred.

The inquest has been told it was a pump failure which caused the tragedy.

Danfoss technical manager Eduardo Gie said in a statement the pump drives, manufactured by Danfoss, were to last for 10 years.

He told the inquest the pumps were installed in 2006 — 10 years before the tragedy.

“The design operating life of the VLT 8000 series is ten years, with an estimated average operating time of each unit being 6000 hours per years,” he said in a statement.

Mr Gie told the inquest the operating life would vary depending on how heavily the pump drive had been used.

A pump drive controls the speed with which the water pump operates.

Mr Gie said a site visit a week after the incident found the last six failures of the pump on the south pump were all earth faults.

It was an earth fault which caused the pump to cut out just prior to the fatal incident.