Autonomous Remote Mine Inspection

Rajant, PBE Group, and Australian Droid & Robot Make History with Successful Autonomous Remote Mine Inspection

Adversity and a keen focus on sanctifying safety galvanized a limestone mine to innovatively address the inspection and restoration of operations following a collapse using an autonomous robotics solution.

In August 2021, disaster struck when a 100-year-old limestone mine in the Southeastern part of the United States collapsed unexpectedly. This was a result of subsidence further causing a massive event underground where the pillar and roof collapsed. Violent air blasts up to 190 mph flew debris and dirt through portals and ventilation shafts. The failure of old pillars left enormous subsidence measuring 800 ft. across and 100 ft. deep.
The mine was evacuated beforehand from a veteran worker who noticed something was wrong that day. Mining Safety and Health Administration deemed no one return working in the mine until an unmanned survey was able to ensure safe conditions. Enter Rajant Kinetic Mesh® wireless networking with powered backhaul affixed to ADR’s unmanned robots and the integration know-how of PBE.


The Mine

Limestone underground operation in the United States

The Partners


PBE Group

Australian Droid and Robot (ADR)

Solution Components

10 ADR Explora XL unmanned robots

Rajant DX2 BreadCrumbs®

The Challenge

Underground, no internet or fiber backbone was available deep into the structure.

Before the collapse, the mine was utilizing a two-way radio system over a leaky feeder that did not withstand the incident. Moreover, it lacked sufficient bandwidth to support any unmanned robot or drone inspection mission.

By eliminating the human factor in favor of an autonomous system, multiple technologies were needed to facilitate ‘safety by separation.’

The Solution

Rajant’s Kinetic Mesh network provided a robust and reliable communication infrastructure that was efficiently deployed for the project, enabling long-distance, low latency wireless networking without infrastructure.

The remote inspection robots, equipped with Rajant BreadCrumbs®, entered the underground area and continued to relay a communications signal to each other through a daisy chain, high bandwidth mobile connection.

With no network or systems in place, the operation needed to handle data backhaul and power the robots. BreadCrumbs were also installed at the surface site providing high bandwidth between the mine entry and the operation center.