According to the company, the PJB Flitmate utilises the highest power underground generator set (340kW at 1000V) ever built for underground coal mines anywhere in the world.

In an underground coal mine, electrically powered production machines like continuous miners, shuttle cars and breaker feeders can be moved short distances in production on trailing cables – but moving them long distances “is about as convenient as having a 240V car with a very long extension lead behind it from home,” the company said.

When “flitting” (moving from one part of an underground mine to another) the Flitmate becomes the power station and is towed along with the machine that it is providing the power to.

The prototype Flitmate machine is now in service in Central Queensland and has completed five jobs, with the company anticipating orders for at least two more machines this month.

PJB’s Phil Berriman said the big issue in meeting the power requirements for newer and bigger underground machines is minimising worker exposure to diesel emissions.

“The bigger the engine, the more important emission control becomes – the technical innovation on this machine is all about emissions control,” Berriman said.

PJB Group general manager Brett Neal said in general, more diesel engine power means more harmful emissions, but not in the case of the Flitmate.

He said every available technology has been employed in this project to minimise harmful emissions.

“We believe that this is the very first underground machine in the world to combine every practical emission control technology to best ensure the health and safety of mine workers,” Neal said.

“What’s also very impressive is that the machine is able to tram any miner in service at maximum speed and up any grade encountered.”

The diesel engine powering the Flitmate is a Caterpillar C15 engine (15 litre), which provides 383kW of engine power.

The turbocharged and charge-cooled (SCAC) engine system has a full authority electronic management system and employs Caterpillar’s ACERT combustion technology to minimise emissions.

PJB added an additional controller to the electronic system, able to communicate with the ECM and to a host of “satellite” sensors and detectors.

All of the electronics communicate on a centralised administrative network and can take both “intelligent” and “intuitive” decisions to optimise performance and safety and manage emissions.

The added controller has a text screen that provides detailed information about the engine operation and even logs data for later retrieval.

The catalytic oxidiser on the Flitmate reduces carbon monoxide and (aromatic) hydrocarbons to very low levels and also reduces levels of diesel particulate matter.