Australian Coal Mine to Enhance Safety Using RFID

By Beth Bacheldor

May 2, 2007—NL Technologies, a Canadian designer and manufacturer of underground lighting and digital communications solutions for the mining industry, is readying an RFID system that uses active 433 MHz tags to track and manage miners and vehicles underground.

To build the RFID capability into its network—a fiber optic backbone that includes 802.11 access points—NL Technologies partnered with WaveTrend, a manufacturer of active 433 MHz RFID tags and interrogators utilizing a proprietary air-interface protocol.

The tags are affixed to batteries worn on miners' belts, says Daniel Rose, NL Technologies' chief operating officer, while the batteries are connected to and power the cap lamps miners wear on their heads. Each tag's unique ID number is associated in NL Technologies' Northern Light Digital Software Suite with a miner assigned that specific tagged cap lamp. The tags can also be affixed to vehicles within a mine to monitor and track the vehicles' locations.

To determine the position of a miner or vehicle, two RFID readers—connected to the NL Technologies access points installed in a mine—calculate the coordinates. Tag positions can be determined within a 30- to 50-meter (100- to 165-foot) radius, Rose says. Location information can also be ascertained, albeit on a broader scale, from a single reader, because every access point has an IP address correlated with a zone in the mine. The access points have a linear range of 600 to 700 meters (1,968 to 2,296 feet).

In addition to the tracking capability, NL Technologies also offers Messenger, a two-way Wi-Fi-based radio enabling administrators to communicate with the miners via text messaging. Administrators can send instructions for the day's work, for example, while miners can easily respond by picking among 50 preprogrammed responses.