Published in the September 2010 Australian Longwall Magazine

After battling through lengthy regulatory approval processes, the communications supplier is making big inroads into the Australian longwall market, winning two major orders from the dominant player Xstrata Coal.

In July NLT won the contract to supply its complete tracking and two-way messaging cap lamp system for the West Wallsend colliery in New South Wales.

The announcement of another big WiFi installation at a NSW mine in the last six months is on the cards, but perhaps the most exciting results will come from NLT’s unique collaboration using its “GPS-like” Reverse Tracking with 3D visualisation software company VRT.

VRT can already create a 3D animated model of a mine underground, along with 3D models of equipment such as shearers, roof supports, BSLs and continuous miners.

The unique aspect of these models is that they are “driven” by real-time information, including parameter values, events, messages, CCTV images, range finder and spatial/position data.

The problem for this software tool was always obtaining data accurate enough to display actual location in real time. The standard technology for tracking in underground mines to date has been a zonal approach, with zones often kilometres long.

But by using the data provided by NLT’s WiFi reverse tracking messengers and tracking tags, the overall 3D model can become a live representation of what is actually taking place underground.

There are even possibilities to use custom 3D models of individual mine workers to show where they are and what they are doing, as well as predicting where they will be in the future.

NLT managing director Tim Haight said everything has changed dramatically since NLT developed reverse tracking.

“Because we have come up with this extremely accurate tracking, mining companies can now get better value from the 3D solution,” he said.

Previously the data from the tags covered distances which were far too big for such an application.

“But now we can bring it right down to such granularity that they can actually show it in 3D,” Haight said.

While the software might not be able to cover all ranges of human movement, Haight said it could be possible to send a mineworker a message, then watch his cap lamp flash in the 3D animated world, plus see the worker look down at his messenger and read it.

With reverse tracking, the readers are already in NLT’s messenger cap lamps but tracking tags can be placed throughout the mine, with tags able to be located as little as two metres apart.

NLT is in talks with the major OEMs as a tag on every roof support should be able to distinguish exactly which one a worker is under.

“Right now we read a number of tags, but we believe we can get the algorithm right to know which tag he is closest to,” Haight said.

By linking everything together through WiFi, it’s possible that automated longwall equipment can be programmed to halt if a worker is in a dangerous position.

This could reduce the risk of crushing injuries from moving roof supports. The common fear for the mines and OEM’s is that the use of this technology may cause miners to become complacent. For this reason, initially this will not be a safety system and SIL (Safety Integrity Level) rated, but should the mines require this, the hardware and software is capable of obtaining such a rating.

But there are more opportunities than safety improvements, as Haight said a tag could even be placed on every cut-through section in a mine.

An effective WiFi network underground will also help reduce downtime.

NLT has integrated its communications technology with Citect’s SCADA package which most longwall mines use, allowing Citect’s software to send alarms and messages to the nearest maintenance person in the event of a fault.

Delta Engineering provides its own software package which is used to manage programmable logic controllers and this system can also make use of NLT’s WiFi network for first fault alarms and messages.

Haight said its communications technology was becoming a high-end productivity tool rather than just a tracking system.

By combining NLT information via dedicated interfaces, Citect data (both real time and historical) and PLC data, everything can be tied together into a single, integrated 3D display, viewable through a web browser, anywhere.

“The mines can use the messenger as a real means of communicating and communicating information as well, so faulty communication and production information can all arrive on the messenger now.”

NLT aims to make fault fixing and diagnostics on its own gear simple so telecommunications expertise is not required.

“We are making the software intuitive enough,” Haight said.

“We’re using this visualisation software to actually look at our nodes.

“For instance, with our WiFi nodes underground we will be able to look at our network using this 3D visualisation software and if there’s a fault, zoom in on that fault.”

Haight said there will be visual images of data going in and out of the fibre presented through the 3D software, letting management know where the problem is, should there be one, as well as instructions on how to deal with it.

“If the fibre is broken or its damaged fibre it won’t show any data going out – it will be that simple.”

To get a rough idea of how the 3D software will look and feel, VRT has a simple interactive demonstration of a longwall mine on its website, which allows you to roam underground and control a shearer.

In that demo, the movement controls on the keyboard are very similar to the keys used in a first person shooter computer game, but the final software product customer’s implementation will be a lot more sophisticated, detailed and powerful.