You dont need to know how each ride physically works to oversee a department.
You have to UNDERSTAND how engineering principles work and UNDERSTAND control systems, so when your very experienced (with this ride, function or system) staff come to you, explaining the situation or discussing a matter with you, you know what they are talking about even if it means you can't walk over to a ride and push buttons on a console.
You can talk over to a ride with this very knowledgeable tech staff who know exactly how to operate the ride, who then can perform those very basic functions while you talk about the actual control systems and mechanics that are happening once that button is pushed. See the difference? You know what systems are actually functioning when you press that button that starts a conveyor, and how that conveyor works. The operator pushing the button only understands the function, not the process.
The department head is going to know about the engineering that goes into running a complex machine like an amusement ride, they don't have to sit down in front of a ride and run it.
Might things change following this inquest? maybe. But it really doesn't make a lot of difference. Unless you are a chartered engineer registered with one of the few societies in the country, you aren't making judgement calls on systems anyway. So even having an engineer in the top job of the maintenance department who could replace a sick operator at a moments notice isn't going to achieve much.
What you are supposed to be is someone up on current industry standards around things like safety and operation and very adept at recognising potential issues before they happen. This is what half of your job is, the running of the department is left to supervisors. You oversee the works and are tasked with bringing in auditors and technical inspectors or 3rd party engineers for advice or to respond to outside requests, changes or incidents. You basically want a chartered engineer prepared to put a recommendation to paper, essentially putting their registration and insurances on the line. I would be surprised if there are any of these people in any theme park in the country. They are the ones that command big dollars and are ultimately singing off on projects and developments for pretty much everything you see around us. If a person has had a hand in building or maintaining it, there's a chartered engineer who has signed off on it.
So, going ahead and making changes to a control system full of buttons and complex controls isn't something someone running the department probably does either. It would be like my boss coming into the office on monday and saying he wants the bottom chords moved higher in all the trusses of this conversion we are doing so they aren't immediately visible from the big glass doors at the end of the building. No problems, i'll just change the bottom timbers out on all the engineered components that hold the roof up and tie the walls together. It's not like it would need a complete redesign to be safe, no big deal.
What seems to have happened at dreamworld though is they have had good, 3rd party, professional advice on many issues of safety, control and operation of their rides, and little to none of it has been implemented. This may not be just an issue with the department head though as they would have budgets to work within, but further up the management chain where the money decisions are really made. Especially when it seems clear they had been told to put a hold on any spending that wasn't already a capital works project.
Really, jail time needs to be an outcome of this. Who gets jailed should ultimately come down to who made the yes or no decisions that placed ALL of us in jeopardy. Not just the people who lost their lives, BUT EVERY PERSON WHO VISITED THE PARK IN RECENT HISTORY.
If there is a long suffering maintenance department burried under the lack of funding decided upon by people like the financial officers, park general manager or even the chief operations officer, then no matter how inept some people in the department were, it's not ultimately their responsibility alone.
In this specific case;
Yes - allowing the ride to return to operation that many times following faults should see you jailed. You ignored even your very poor control methods/standards and people died because of it. The ride should never have been running, and if you advised park management of this and they put pressure on you to keep it open, you should have grown a spine and told them it's an issue of safety and you weren't prepared to open the ride until the electrician arrives to inspect the problems with the pumps.
and
Yes - Not approving a MAJOR safety upgrade to your ride that would have made its operation easier and implemented a control system that no longer required the input or judgement of operators, which would have meant these people would not have been killed, you go to jail.
You, or they (together) sat there in front of a bunch of numbers and discussed the works and ultimately decided an amount worth less than your monthly salary was too great to ensure that your guests will be afforded with at least a basic level of safety that should have been (and was previously recommended) performed long ago. You put a price on each of those people's heads that amounted to a few thousand dollars each.
You all should go to jail. And if they bring in a new law that requires every amusement operator in the country to register for a licence to operate amusement rides, you should be struck off the register to make sure you are NEVER in the position to weigh up the cost of human life again. You were supposed to weigh up the cost of upgrading the ride vs shutting it down, you weren't supposed to weigh up the cost of safety vs the cost of human life. I hope it comes out in the inquest if these same methods were applied to any other rides too, because it's these people that need to be turned out for all the media and the general public to see.
There needs to be a clear message sent out that it's not OK to judge who lives and who dies. If you cannot afford to maintain, upgrade and operate a complex, dangerous machine within the grounds of what the safety industry, and hell, members of the public consider an acceptable risk; then you don't get to open the chain links or gates to that ride until you come up with the funding to do so. When it starts becoming a business of making profit for shareholders, you start killing people and that should never be acceptable. The board members who stepped down should have necked the lot of them and turfed them all out as they were out the door themselves.