Scope of Supply

The Grasstree Mine project involved the commission and installation of a two-way messaging and tracking system that accurately followed the location of personnel and equipment underground, resulting in improved safety and efficiency.

Site Detail

Grasstree Mine is located within the German Creek mine area in the Bowen Basin coal measures of Central Queensland, Australia. The German Creek mine houses the existing underground operations of Central and Southern Collieries, and the German Creek open cut mine. Three hours inland from Mackay on the coast, the mines are serviced by the town of Middlemount, with the towns of Tieri and Dysart in close proximity.

Project Challenges

Being the first large underground coal application for NLT Digital in 2007, a number of challenges presented themselves – including intrinsic safety (IS) approvals. Because the client was open to receiving non-IS nodes to expedite installation of the system, deliverables needed to be modified to allow for future upgrades. The messaging and tracking communications system had to be designed and certified for use in Queensland Underground Coal Mines.

Project Details

The Grasstree project involved the design, supply, testing, and delivery of a two-way tracking and messaging system to the mine. Today, the solution now provides coverage for main travel areas in both Grasstree and the Southern workings with the ultimate goal of achieving near 100% underground coverage, including across the mine longwall face. Coverage is provided for two-way messaging and reverse tracking with the direction of travel.

Currently included in the Grasstree solution are:

  • 575 Reverse Tracking Messenger Cap Lamps
  • 890 RFID Tags (Locator and Vehicle/Asset)
  • 52 T2 Nodes
  • Two 3-Fibre Port Nodes
  • Three T3 Nodes
    Four Portable Nodes
  • 48 UPS
  • 40 Ranger VoIP Handsets

NLT’s Digital Mine™ software is designed to sit on top of the NLT Digital Network™ and allows on-site users send and receive messages to underground miners. It monitors the location of personnel and equipment, allowing operators to search for people and assets, or particular skill sets, on the mine site.

The project was delivered in two stages. The first was the implementation of IS Messenger camp lamps and tags, initially installed with a non-IS Wireless Access Point (WAP). After the Node received IS approval, all non-IS components were replaced. The final IS Node as an integral IS UPS patch panel with fibre in and out, and is supplied by a 12V power supply.

The original fleet of Messenger™ Cap Lamps have been fully replaced with Reverse Tracking Messenger™ (RTM) Cap Lamps. To enable NLT’s unique reverse tracking method, RFID tags are situated throughout much of the underground and surface operations.