Developed in the wake of the 1986 Moura mine explosion, the Numbat mine safety vehicle turns ten years old in August. Yet, a decade on, the bold project seems little closer to being delivered into the industry for which it was designed.

The reasons for this are complex and have as much to do with human psychology as questions over who should take ownership and responsibility for an expensive piece of equipment which only operates under exceptional circumstances. This quandary is at the heart of the Numbat debate.

The Numbat was developed by the CSIRO's Exploration and Mining division in response to an industry request following Moura and earlier incidents such as Box Flat, when would-be rescuers were themselves killed in abortive rescue attempts.

There was a push within the industry for the development of a remotely controlled vehicle which could safely sample a mine's underground environment following a disaster, prior to rescuers going underground.

Yet, even today, delivering the wish-list for the original Numbat idea would be daunting. The basic vehicle needed to have vision through all atmospheres underground, it needed to operate over a wide temperature range and in explosive atmospheres, and it needed to be 100% reliable.

Principal research engineer at the CSIRO's Exploration and Mining division, David Hainsworth, has been involved with the Numbat since day one. Hainsworth believes that achieving all these parameters is still not possible.

"I think we have achieved 80% of what was required but to get the other 20% proved too expensive," Hainsworth said.

It soon became clear that locating a dedicated Numbat at each mine was not economically feasible. To function properly, they would need constant maintenance and operators trained in their use.

The most logical owners of the technology were the Queensland and New South Wales Mines Rescue services, which would own one or two Numbats for deployment when necessary.

But even these organisations did not have the budgets to carry a vehicle like the Numbat, which is partly why the ageing prototype continues to be housed in a CSIRO workshop where maintaining it in a state of readiness has become an increasingly difficult task. (A related issue is to do with what happens when the Numbat arrives at a mine in the wake of a disaster when emotions are running high. If those co-ordinating the rescue effort are not both familiar and comfortable with the technology they may elect not to use it.)

As the Numbat project evolved, so too did the industry's perception of what it should do. The original guidelines for the machine were heavily coloured by what had just happened at Moura and the Numbat was, in a sense, designed to cope with another Moura.

Guided by an industry taskforce, the CSIRO originally designed the Numbat to travel two kilometres underground - the Moura incident occurred 1.5km from the surface. The Numbat would gain mine access via a drift, as at Moura. Deeper and more extensive New South Wales mines with shaft access would clearly pose a problem for the Numbat.

While the Numbat was steadily enhanced over a lengthy period in response to industry feedback - the limitation on distance was being resolved by giving the vehicle a 10km capability - what began to emerge was that the Numbat could not be all things to all people.

The closest the Numbat came to being used in an actual disaster was after the 1994 Moura disaster. The vehicle was transported to the mine within less than 24 hours, but its deployment was delayed by technical problems and dissension about what course of action to take.

"We were sitting in a room planning what the Numbat would do and we were within minutes of sending it down when the mine went up for the second time," Hainsworth recalled. "We were so near and yet so far from using it for its designed purpose. It was reported [incorrectly] in the newspaper that the machine failed, and that perception is hard to erase."

Losing the Numbat underground in the Moura 1994 disaster may have been a good thing. It would have shown that the Numbat actually worked, if only briefly.

The industry began to turn away from sending rescuers into potentially hazardous mine environments, and as the idea of self-rescue gained currency, perceptions about what the Numbat should or could do changed too.

"What struck people as being inadequate with the Numbat, which was purely a reconnaissance vehicle, was that if you did see anybody you couldn't do anything about them - you couldn't pick them up and bring them out," Hainsworth said.

The industry wanted more capability so it was decided to evolve the vehicle into a bigger concept that could not only bring people out but could move blockages out of its trajectory using an attached crane or bulldozer blade. If the Numbat's path was blocked it could do nothing to move things out of the way.

"With a large vehicle you have to overcome two problems - getting a power source like a diesel engine to work when there is no oxygen, and having a communication system that can make it remotely controlled. Fortunately, all the Numbat communications and control systems can be directly used in a large vehicle, which leaves only the power source problem to be solved," Hainsworth said.

A third option was then mooted to adapt a conventional mine vehicle by bolting on an oxidising system to allow the diesel engine to work in an oxygen-deprived atmosphere.

The CSIRO's Mines Safety research group is currently taking this aspect of the Numbat work forward by developing a closed cycle gas turbine engine for this potential application.

A proposal for ACARP funding submitted earlier in the year to support this work was one of 44 proposals shortlisted for full proposal submission from a total of 113 received submissions.

Still unresolved are questions of ownership. Who should be responsible for the maintenance and deployment of a highly specialised and expensive piece of equipment that may only be called on once every six years?

Yet, despite any negative perceptions about the Numbat project, its legacy is all-important. The Numbat project brought together into the CSIRO a team of people with world-class expertise.

All the Numbat's technologies - gas sensing, control methods, power systems, software and user interfaces - have found their way into numerous other CSIRO projects. Drag-line automation, horizon control work, highwall mining guidance, underground communications, LHD automation and current mine safety research can all be traced directly or indirectly to the Numbat.

It is a track record worthy of celebration. Happy tenth birthday, Numbat.