Known for its successful PED (Personal Emergency Device) paging system, Mine Site has been developing TRACKER as a standalone system, or to be used in conjunction with Mine Site Technologies’ VDV radio system. TRACKER is an entirely new system which the company hopes to integrate with PED by next year.

“We reviewed a lot of off-the-shelf tags from large companies, but none seemed to give the reliability and ruggedness required by underground mining applications,” said Denis Kent, Mine Site Technologies. “So we went back to the basics and developed our own active tag (which is basically a miniature radio transmitter). This included developing the special coding techniques to handle the unique identity of each tag, and allowing the ‘read’ Beacon to receive and correctly decode the ID from a number of units on the move.”

The base station PC keeps records of all entries and exits, and present location (of both personnel and vehicles) underground. This database can be utilised to effectively monitor and manage the time personnel spend underground.

The long range beacons have a read distance of approximately 40 metres, depending on the tunnel shape and dimensions, and are designed to read ten tags in a vehicle travelling past at 40km/hr. With beacons at strategic locations underground, the location of personnel and equipment can tracked within zones (ie between two beacon locations).

There are several tag types for this system depending on the environment and application required. Some tags are interfaced to cap lamp batteries, where they draw their power and become part of the personal equipment of the person working underground or are standalone units with internal long life battery.

Information from the Beacons is reported directly to the host computer, via leaky feeder radio or hard-wired link (optic fibre, twisted pair, etc).

The software features include:

* Password Protected tag entry system.

* Alphabetical list of people currently underground.

* Highlighting a person, in the list, will display their details.

* Updated every three seconds.

* Stop button, to stop ‘Read Heads’ from reading.

* Forgive button, to log people out if permitted by management.

The active tags worn by personnel, or attached to equipment, are constantly transmitting their unique ID. As they pass within range of a beacon this information is recorded and sent to the main database PC.

Other features include a current list of personnel currently underground and the zone they are in can be easily printed in an emergency. Icons next to a user’s name represent trades, first aid and rescue personnel, etc.

“The mines who have expressed interest to date are as interested in the productivity/cost saving uses of TRACKER, as the safety aspects of it. Better managment of vehicle fleets seems of particular interest, as the mines can calculate some hard cost benefits, and therefore do an easier cost justification for getting capital approval,” Kent said.