A Dreamworld maintenance boss has conceded there was a “total failure by everybody” at the Gold Coast theme park to identify safety issues on the Thunder River Rapids ride.

An inquiry into the deaths of Cindy Low, Kate Goodchild, Luke Dorsett and Roozi Araghi resumed at the Southport Coroners Court on Monday.

They were killed on the ride when their raft collided with an empty vessel and flipped backwards in October 2016.

The inquest has been told some ride repairs were delayed for budgetary reasons and Dreamworld’s safety guidelines had warned of the potential for rafts to tip.

During questioning by counsel assisting the coroner, Ken Fleming QC, Dreamworld maintenance planner Grant Naumann agreed the Thunder River Rapids ride was “completely unsafe”.

Earlier, Mr Naumann told the inquiry that ‘a number’ of modifications were made to the Thunder River Rapids ride in 2016, including on a section leading to the conveyer belt.

“We installed some framework at the base of the conveyor, so leading up to the conveyor,” he said.

“That framework was put in there in the event that a water level dropped, the raft couldn’t tip over. That sort of thing.”

Under questioning from barrister Matthew Hickey, acting for Ms Low’s family, Mr Naumann said there were discussions about whether repairs could be delayed for budgetary reasons.

“Were there decisions made for certain works to be deferred because they couldn’t afford to be done from time to time?” Mr Hickey asked.

“There were discussions with regards to the cost of a repair or the cost of a replacement and if it was decided that that could be deferred until such a time as it would fit the budget better, yes that happened,” Mr Naumann responded.

The inquest also heard that Dreamworld’s safety guidelines warned of the potential for rafts to tip on the ride.

Maintenance team leader Stephen Murphy was the first to take the stand and was asked if he knew the consequences if the ride conveyer continued when a pump failed.

He said no one had brought it to his attention.

He was then shown guidelines warning it could tip.

“The Rapid Ride Alarm will be sounded when the main water pumps stop for this ride. If the pumps stop for this ride then there is the potential for the rafts to become a hazard to the guests riding them,” the document said.

“The rafts are very heavy and there are a lot of underwater obstacles that could cause the rafts to tip or entrap the guests.”

Mr Murphy also told the court he did not know what the emergency stop button on the ride’s main operator control panel did, and that he had never tested it.

He said he had regularly checked other emergency stop buttons on the ride.

“I know the e-stop on the unload that stopped the conveyor because I used that as part of my morning checks,” he said.

Mr Murphy said an order from a management meeting instructed staff to shut down rides if they broke down three times in one day, which was a change from previous breakdown policy that dictated a ride be shut down after two issues.

The Thunder River Rapids ride had already broken down twice on the day of the fatal raft collision.

A fortnight of hearings were held in June and shed some light on the tragedy, with evidence of operator confusion, unclear emergency plans and an under-resourced safety unit.

-ABC