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Partners Australian Droid and Robot, PBE Group, and Rajant Reach 1.7 KM to Reclaim and Restore Operations for Collapsed Limestone Mine Protecting Lives and Jobs

Malvern, Pennsylvania (USA), Jan. 20, 2022 (GLOBE NEWSWIRE) — Rajant Corporation, the exclusive provider of Kinetic Mesh® wireless networks, and its technology partners Australian Droid and Robot (ADR) and PBE Group, have completed the deepest remote underground mine inspection in history. Using ten ADR Explora XL unmanned robots and a wireless below-ground communication network, a mobile infrastructure depth of 1.7 kilometers was achieved to enable the reestablishment of operations at a collapsed limestone mine and restore jobs.

A significant, unexpected mine collapse occurred in August 2021 causing an expulsion of air carrying dirt and rocks that flew out of all portals and ventilation raises. The air was estimated to be moving around 120 mph. It was determined that this collapse was caused by the failure of very old pillars (40 to 70 years old) thus creating a substantive surface subsidence. The surface subsidence measured approximately 800’ (ft) across and over 100’ (ft) deep. No one was injured in the incident, as the mine had been evacuated well prior to the incident. Working with the Mining Safety and Health Administration (MSHA), the operator and MSHA determined no one should enter the mine until some type of unmanned survey could be conducted to assess the conditions of the mine safely. The solution to achieve this came through the collaboration of ADR, PBE, and Rajant.

“Prior to the collapse, the mine had a two-way radio system running over a leaky feeder,” shared Rajant Sales Director Todd Rigby. “The leaky feeder was not functional following the collapse, nor did it have sufficient bandwidth to support unmanned robots or drones. Rajant BreadCrumbs® were installed by Rajant’s channel partner PBE mostly at the surface of the mine to provide a reliable high bandwidth link from the portal to an emergency operations center overseeing the remote surveying done by ADR and its fleet of all-terrain ground robots equipped with BreadCrumbs. The robots initially dragged three network infrastructure points into the mine and then staggered along various routes up to 1.7 Kilometers deep. During the longest mission, the robots were transmitting 80 Mbps, and included high-definition video and Lidar to create a virtual 3D model of the mine.”

“ADR keeps a small fleet of robots ready to go for emergencies, but this was going to require more units with different sensors and capability,” said Dr. Joe Cronin, Operations Manager and one of the founders of Australian Droid & Robot. “We quickly built more robots and undertook a thorough testing regime to imitate the conditions and distances we would experience in the US. We had teams all over Brisbane, and at one stage, we had robots strung across more than one suburb, controlled from a central location. The robots were shipped to the US less than a month later and were accompanied by Andre Preller, Head Electronics Engineer and Callum MacDermid, Senior Robotics Engineer. After a day’s testing on the surface, the robots entered the mine, each robot relaying the communications signal to the next, creating a high bandwidth, daisy-chain network into the mine. A week later, the team had acquired enough data for the mining team to be able to restart operations – the only company globally who could assist with the right equipment in the right timeframe.”

“Before the collapse, PBE was the mines communications infrastructure provider. When we learned about the need for unmanned inspection after the collapse, we focused on finding the best solution for fast, flexible deployment and high performance,” added Rob Koch, Director of Technology, PBE Group. “The mine needed a high throughput, flexible data network to support a broad and changing set of inspection deployments. The Rajant mesh technology was the clear choice for this need. In execution, the challenge was to design network elements deployed into the mine by the robots themselves. We moved quickly to source the best antenna technology for the robots and backhaul nodes. Then we went onsite to build the robot deployable nodes and surface network to move data to the inspection operation center. The network and antenna elements provided plenty of time to facilitate the inspection event. We are glad the mine chose PBE on this groundbreaking project to safely bring the mine back into production using the best technology available.”

A video case study documenting the achievement is available. The mine intends to implement a mine-wide Kinetic Mesh network. In the future, if they were ever to have an issue of instability, they can simply run a single ADR robot into the mine using the preexisting network infrastructure, protecting the sanctity of worker safety and uninterrupted productivity.


About Australian Droid and Robot

Queensland technology company Australian Droid and Robot (ADR) deliver cutting-edge technology to companies right across Australia and across the world.  Taking the world’s best technology and innovation and adapting and modifying it to meet the needs of Australian companies and Government agencies, ADR is changing the way businesses operate.  ADR supplies a range of products and services including:

  • Industrial Robotics and Automation;
  • Drone and Robot Services; and
  • Custom Robot Solutions.

ADR’s approach is ‘Safety by Separation’ – Mining utilises the Hierarchy of Controls to mitigate risks. If the two most powerful controls; Elimination and Substitution cannot be relied on and Engineering and PPE are not relevant, automation and robotics allow personnel to conduct hazardous tasks remotely. Therefore, ‘Separation’ is a control where personnel and the hazard are disconnected – they are not in the same place. When this control fails, no personnel are exposed to a hazard.

About PBE Group

PBE Group is an international manufacturer and systems integrator in the communications, safety, and power verticals. We serve the public safety, cellular, tunneling, construction, data center, and mining sectors, celebrating our 50th anniversary in 2021. PBE Group provides customized adaptive solutions when reliance on safety and productivity is essential. We integrate our industry-specific manufactured products and best in class 3rd party products delivering robust and commercially viable solutions. Our international growth comes from three main verticals: Power, Communications & Data, and Safety Products, the essentials of any industrial project. Our experienced sales, engineering and production teams have delivered 800 projects in more than 60 countries worldwide. We have a global install base of certified and warranted power and communications infrastructure, service centers and highly skilled engineering capabilities. PBE offers hire/lease as well as direct sales. To learn more, visit

About Rajant Corporation

Rajant Corporation is the broadband communications technology company that invented Kinetic Mesh® networking, BreadCrumb® wireless nodes, and InstaMesh® networking software. With Rajant, customers can rapidly deploy a highly adaptable and scalable network that leverages the power of real-time data to deliver on-demand, mission-critical business intelligence. A low-latency, high-throughput, and secure solution for a variety of data, voice, video, and autonomous applications, Rajant’s Kinetic Mesh networks provide industrial customers with full mobility, allowing them to take their private network applications and data anywhere. With successful deployments in more than 70 countries for customers in military, mining, ports, rail, oil & gas, petrochemical plants, municipalities, and agriculture. Rajant is headquartered in Malvern, Pennsylvania, with additional facilities and offices in Arizona and Kentucky. For more information, visit or follow Rajant on LinkedIn and Twitter.



Alice DiSanto
Rajant Corporation