New technology enables two-way communication from
deep underground.

Reliable two-way communication between underground miners and the surface in the event of an accident has long been on the mining industry’s wish list. When disaster strikes, communication is clearly crucial for fast and safe evacuation, or for a successful rescue.
 
The problem the industry has faced for decades is that conventional radio technology does not penetrate deep under-ground. Consequently, existing two-way communication relies on power and cable-based infrastructure, which in an accident such as a rock fall is often lost.

It has been a seemingly insurmountable problem, but one that was eventually taken on by CSIRO, with support from the Australian Coal Association Research Program (ACARP).

The scientists involved have now successfully trialled the first two-way wireless communication technology able to send a signal through many hundreds of metres of rock. It is also designed to send a pre-set message at the press of a single button, increasing the chances of an injured miner being able to activate it.

The new radio technology, which has attracted international interest, has been licensed to Australian company Mine Site Technologies to allow them to enhance their existing personal emergency device (PED) product for two-way communication.

Existing PEDs, which also include core technology from CSIRO, allow one-way wireless communication from the surface to the underground. Part of the lamp/battery kit worn by miners, PEDs have now become standard equipment in most Australian coal mines.

Using a low-frequency radio transmitter on the surface, PEDs can also penetrate hundreds of metres of rock. However, this requires high transmission power, and the surface antennas typically have a circumference of up to several kilometres.

CSIRO research director Dr Jay Guo says that to use the same transmitter system from underground for the return signal would, of course, be impractical. Instead, the new two-way technology still uses low-frequency radio signals, but the message a miner sends to the surface travels via small repeater stations throughout the mine.

“The added advantage of using repeaters is that we can locate the miners within an accuracy of about 35 metres,” Dr Guo adds.

In Tasmania’s Beaconsfield mine collapse, a two-way PED would potentially have allowed the two trapped miners to quickly transmit their location and general circumstances, rather than wait days for rescuers to locate them and know their fate.

Dr Guo says the construction and positioning of repeaters has been designed to ensure the system will function after any major incident.

Mine Site Technologies business development manager Denis Kent says the two-way PED closes the loop in mine communication. “It is the only device of its kind in the world and will set Australian technology as the international benchmark in mine safety,” he says.

The CSIRO Information and Communications Technology (ICT) Centre’s business development manager for wireless technologies, Iain Walker, says patents are in place and a market-ready product is expected in about two years. “Supplying the technology will use a high proportion of Australian services and manufacturing capabilities. Export revenue is expected to be $100 million over the 10-year licensing deal with Mine Site Technologies,” he says.

CSIRO will be retained as a research consultant for product development and will share in the licence fees on product sales with ACARP.