Details of the annual shutdown and inspection of the ride have been discussed as Dreamworld maintenance staff continue giving evidence at the coronial inquest into the tragedy.

Sydney mother Cindy Low, siblings Luke Dorsett and Kate Goodchild and Mr Dorsett’s partner, Roozi Araghi, were killed on October 25, 2016, when the ride malfunctioned and the raft they were riding in flipped over.

Maintenance planner Grant Naumann, who had worked at Dreamworld for several years in his more administrative “hands-off” role, told the inquest the ride often had maintenance issues that were fixed immediately or scheduled for resolution.

He said that, earlier in 2016, the ride had been shut down for four weeks for annual maintenance works which involved a complete breakdown of the ride and thorough inspection, with a sheet of tasks signed off by various engineers and tradesmen.

The shutdown saw a team of eight people break the Thunder River Rapids Ride down, including fitters, boiler makers, trades assistants, electricians and other external contractors.

During the 2016 annual shutdown, timber slats on the conveyor belt were replaced in an order of “new, good condition, old”.

The inquest had earlier heard the timber slats had been changed to a system of full-width slats between shorter slats, which potentially created a “pinch” risk for guests.

The inquest also heard that an official safety document warned of the hazard to guests if the two water pumps failed.

A work order for the 2017 annual maintenance was entered into the system the day after the tragedy, without any information on who had entered the work order.

Mr Naumann said it was his own best practice to always enter his name when logging a work order.

He said it was "beyond him" why the annual maintenance order had been raised the day after the tragedy.

In one interview with inspectors after the tragedy, Mr Naumann detailed an incident where engineers noticed the bearings under one of the water pumps was overheating.

“If the bearing overheated it could have collapsed, drawing more amps, and the operator would have shut down the ride,” Mr Naumann said in the interview.

The bearings were replaced, bringing the internal temperature of the pump back down to safe operating levels.

Another interview with an inspector, after the tragedy, commented on a “significant amount of corrosion” on the Thunder River Rapids Ride, which would have been there for more than a year.

Mr Naumann said he believed that the corrosion would have been noticed and scheduled for repairs.

Asked about a statement he gave after the tragedy that implied budgetary decisions would influence whether maintenance would be completed on the ride, Mr Naumann said he had made a “poor choice of words”.

"Were there decisions made because they couldn't afforded to be done from time to time?" barrister Matthew Hickey asked.

"There were discussions done with regard to the cost of a repair or a replacement, and if it was decided if that could be deferred to such a time as it would fit the budget better, yes that would happen," Mr Naumann said, adding such deferrals were usually cosmetic or minor.

Mr Naumann agreed that the annual maintenance shutdown would have been an ideal time for risk assessments to be taken on key elements of the ride.

Mr Hickey, representing the Low family, asked if the annual shutdown would have been a suitable time to assess the potential for a water sensor to be installed in the ride to immediately alert operators if there was a pump failure.

The inquest had earlier heard that ride operators were expected to assess water level just by watching the water, not through any official alerts or technical warnings.

"Whose job was it to determine the safety of a ride like this?" counsel assisting the coroner Ken Fleming, QC, asked Mr Naumann.

"Everybody's," Mr Naumann said.

"Are you then saying there has been a total failure by everybody to identify the safety issues in respect of this ride?" Mr Fleming asked.

After a pause, Mr Naumann said: "In hindsight, yes."

Mr Naumann was excused and junior Dreamworld engineer Gen Cruz was called to the stand.

Mr Cruz was hired in 2014 and told by his manager Chris Deaves to begin a review of the maintenance and documentation of each class 2 ride in the park - the Thunder River Rapids Ride was a class 2 ride.

Mr Cruz said his review, which he is still completing, had identified missing ride manuals, engineering drawings and maintenance paperwork.

The junior engineer said his role was focused on bringing Dreamworld's ride maintenance up into line with the national audit tool, but he had not yet reached the Thunder River Rapids Ride to review it when the tragedy occurred.