MINE SAFETY
Booyco Electronics Engineer and Developer,
Frank Schommer, said: “Based on a high
frequency wave transmission, the new VDS
technology has been developed to comply with
the latest safety regulations for moving vehicles
on mines.”
While these high frequencies do not penetrate
rock in underground mining environments like
low frequencies can, they are able to detect other
vehicles at a greater distance, according to
Booyco.
“Like the pedestrian PDS, the Booyco VDS’
functionality is based on different ‘zones’ within
the radio field around each vehicle that is created
by a transmitter; the distance of each zone from
the vehicle can be defined by the customer,
depending on their actual conditions and specific
vehicles on site.”
Schommer gave an example: “The system
can be set so that it delivers a warning to the
operators at a distance of 50 m. If no action is
taken after that warning, and the distance
between the vehicles is reduced, then a second
zone is entered, and a command is generated
for the operator to reduce speed. If speed is
not reduced and the vehicles continue to get
closer to each other, an intervention is
triggered by the system to slow the vehicles
down.”
The accuracy of the system ensures there is
enough reaction time after warnings are given for
the operator to act, reducing the possibility of a
collision, according to Booyco.
While the system caters for larger vehicles
with longer distances between them – such as
surface mining load and haul operations – it is
also applicable underground as it can measure
long distances between machines through
tunnels, according to Booyco.
Booyco Electronics’ PDS system – based on
very low frequency wave transmission – can,
meanwhile, penetrate tunnel sidewalls
underground, allowing the detection of
pedestrians out of sight around a corner, but over
shorter distances. This is why Schommer
recommends using the VDS and PDS in tandem
underground.
“Combining these technologies allows mines
to improve safety between vehicles – where the
distances to be measured are longer – as well as
between vehicles and pedestrians – where it is
important to detect workers who are closer but
not visible to the operators,” he said.
Australia first
Strata Worldwide recently achieved an Australia-
first application of proximity detection on
underground shuttle cars in a Queensland coal
mine with one of the world’s leading mining
companies.
As a proactive safety measure, the miner
International Mining | OCTOBER 2019
The E-A-Rfit Dual-Ear Validation System from 3M
can test the effectiveness of ear plugs or muffs
while they are being worn, giving accurate
results in seconds, according to the company
undertook extensive research on Strata’s
HazardAvert PDS technology, with both the client
and Strata Worldwide working together to test
and trial the technology in underground coal
mining environments. The miner’s primary goal
was to reduce the potential risks to people
working in close proximity to mobile equipment.
HazardAvert proximity detection field
generators, installed on equipment, form
electromagnetic (EM) warning and danger zones
around the machinery, according to Strata
Worldwide. These zones are detected by the
HazardAvert Personal Alarm Devices installed on
miner cap lamps or worn on the miners’ belt.
When the zones are breached, either by a miner
entering the zone or by the shuttle car
approaching a miner, the system alarms and
alerts both parties. To overcome situations where
reaction time is limited, the system can be
interfaced into the controls of the equipment to
automatically slow or stop the machinery, the
company added.
Strata’s Michaud said the company’s patented
EM technology is not impacted by the coal seam,
mining curtains or other obstacles that might
block line of sight. The EM technology creates a
very stable and precise zone around the
machine, according to Michaud. In many
operating scenarios, the operator must stand just
a meter or so away from the machine in order for
the system to pick up the interference.
He added: “The HazardAvert EM system is
able to create customs zones with cm accuracy.
The precise and consistent zones reduce the
nuisance alarms which increases operator
acceptance of the technology.”
Mining companies also benefit from the ability
to maintain the PDS equipment on their own,
with the modular design enabling them to switch
out components without the need to call on
Strata personnel.
Lastly, the performance of HazardAvert is not
impacted by the number of people around the
vehicle, incurring no additional performance
latency whether there are five or 100 people
around the machine, according to Michaud. “This
is critical for areas where there is a large number
of machines and people in a confined space,” he
said, adding that the HazardAvert system was
the first to achieve an EMESRT Level 9 CAS
performance rating.
PDS has been used on shuttle cars in the US
and South Africa in line with the aforementioned
regulations, but this mentioned Queensland
installation is the first approved system to be
introduced in a coal production scenario in the
country, according to Strata.
At the recent AIMEX 2019 event, in Sydney,
Australia, Paul Mullins, Global Product Manager
for Strata, provided IM with some more detail on
this recent project win, which was the
culmination of two years of due diligence work at
the mine. Over this period, underground shuttle
cars were fitted with the required proximity
detection technology as they were brought in for
overhaul, allowing the mine to keep up with its
coal production targets.
The physical installation of the PDS was
undertaken at Komatsu’s Rockhampton facility, in
Queensland. Komatsu worked with both Strata
and representatives from the mine operation to
re-design the control system of the shuttle cars
to ensure the system effectively integrated with
the machine, according to Komatsu.
“In doing so, Komatsu were able to ensure the
shuttle car automatically functioned in the
manner requested by the mine operation, in the
event the PDS alerted the presence of mine
personnel,” Komatsu said.
The machine was designed to slow down when
miner personnel entered a ‘warning zone’ and
stop in the event mine personnel became too
close to the shuttle car and entered the ‘stop’
zone.