Illawarra Coal engaged SOTO Consulting Engineers to conduct a remote inspection of the rill tower and conveyor of the Dendrobium Mine in Kemira Valley, Illawarra. The Dendrobium Mine is an underground longwall operation which produces 5.2 Mtpa of raw coal (3.6 Mtpa of clean coal) with a rill tower scaling 128m high. With partially compromised access, this rill tower alongside key structural features of the location’s conveyor, have historically presented a monitoring challenge that required the expertise of SOTO’s highly skilled audit engineers and drone technology.

Initial Scope:

The SOTO AeroCam service, which combines drone and video technology readily applicable to full scale site inspections for auditing purposes, was specifically sought out by Illawarra Coal to fulfil the mine’s inspection requirements to a high degree of safety and efficiency. This project called for meticulous assessment processes, for which SOTO is well known, including a close-up data and imaging analysis of the structural integrity of Dendrobium Mine’s rill tower and conveyor.


With the capacity to hover 130 metres above ground like a robotic hummingbird while recording live film footage and stills in full hover mode, the SOTO AeroCam presented optimal means to execute a thorough inspection of the Dendrobium Mine.

The device was operated remotely from a secure base on the ground by a fully certified pilot alongside a SOTO audit engineer—viewing an HD monitor in real time—during the inspection exercise. The SOTO AeroCam’s three-person crew divided the tasks of controlling the aircraft and focusing on the image capture, to ensure the safest and most accurate results.
The SOTO AeroCam craft was flown into target areas with a specially mounted camera capable of high-resolution photo stills and video or thermal imaging. The AeroCam easily and quickly navigated around the upper levels of the site’s structures, including the rill tower, unimpeded, in stark contrast to the difficult and limited access that traditional methods employing elevated working platforms (EWPs), harnesses and rigging, would have achieved.

Use of the SOTO AeroCam allowed site shutdown to be bypassed, along with the manual tasks and expensive associated infrastructure normally required to complete an audit. An inspection that would normally take a week to execute was performed in entirety within a single day.


SOTO’s AeroCam service enabled a thorough inspection of the Dendrobium Mine with minimised time and investment as requirements for the job’s execution, and maximised access, efficiency, safety and accuracy.

Where the usual cost of an inspection of this scale would begin at the $10,000 mark just to obtain the data, a dramatic cost saving for the hire of the device and the ensuing analysis including full engineering assessment and report was a standout bonus for Illawarra Coal. In avoiding exposing personnel to hazardous conditions, SOTO’s AeroCam also proved a much safer means of obtaining the required data than conventional methods.

A total of 262 photographic stills were obtained during the inspection process, which were used to produce the detailed report that outlined new information vital for future site maintenance.

The SOTO AeroCam markedly unearthed future maintenance areas that were previously too difficult and risky to audit, due to limited access. Furthermore, a degree of corrosion in some of the bolts and other items in the structure of the conveyor was observed, which would not have been possible without the drone’s advanced flight-capture imaging capabilities.

These degradation issues did not require immediate attention but are now noted for future maintenance procedures. The data collected from the inspection now forms the basis of an ongoing history of the asset’s condition in order to monitor any issues over the long term.

SOTO is thrilled to have been able to offer the most advanced available drone and video technology in the form of the SOTO AeroCam to execute the most efficient and accurate inspection possible of Illawarra Coal’s impressive Dendrobium Mine.

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SOTO Consulting Engineers have been providing world-class engineering services for over 20 years. We operate at the forefront of technology to ensure we can respond to your unique business and project requirements quickly, accurately and cost effectively. Get in touch to find out how we can save you time and money no matter how complex your problem may seem.

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