The world’s first high-speed radio-frequency communication system
that allows one to access the Internet from underground has been
developed in South Africa. The high-speed data network is used over
the standard leaky-feeder system to allow the cable to be used not
only for low-speed data communication and analogue video signals
but also for high-speed digital-data communication and Internet
capability.
The product has been developed by a specialist in communication
technology for confined spaces, Mine Radio Systems (MRS), and is
known as the Flexcom cable modem termination system (CMTS), an
upgrade on its Flexcom system, which provides two-way instant
voice, data and video communication. „The new product uses Nortel
Networks cable modem technology, used in North America for
high-speed Internet access.
„This data network, using adaptable proconcrete block crusher for saletocols such as TCP/IP over
leaky-feeder cable, allows the mines to send tremendous amounts of
data at high speed. „That is, 30 megabits per second as opposed to
the standard Flexcom system, which transfers data at 9 600 bits per
second.
„This makes it 30 000 times faster as far as the data transfer is
concerned,“ observes MRS director Ken Morrell.
The system has already been installed at two mines in South Africa,
at Koornfontein coal mine’s Gloria shaft in Mpumalanga and at
Western Platinum’s Karee mine in Rustenburg, in North Wmanufacturing process of artifical zirconest
Province.
The first installation of the system outside of the country is
currently under way in Canada. The product will continue to be
manufactured solely in South Africa and distributed to MRS’s
worldwide operations in Canada, the US, Mexico and Australia. Some
of the applications of the Flexcom CMTS are for fully-controlling
conveyors, for the monitoring and controlling of all environmental
aspects in the mine, such as hazardous gases, air flow and air
quality, for tracking personnel and equipment and for the visual
monitoring of hazemag horizontal impact crusher parts supplierscritical operations and areas. „Basically there is no
type of data that cannot be transported over this communication
system,“ states Morrell.
„Normally high-speed data is sent over fibre optic cables, but the
beauty of this system is that it gives users the ability to do this
if they only have a voice communication system installed.
„This is because components can be changed to upgrade that system
in order to handle the high-speed data.
„This eliminates the costly necessity of having a number of
differenmachines used in stone crushing unitt cables installed at a mine to accommodate the various
technologies,“ he continues. The system consists of a head-end unit
with a server communicating with up to 1 000 client units in a
point-to-multipoint network configuration.
As the Flexcom-CMTS system is based widely on Ethernet protocols,
it can easily be integrated with any Ethernet-based product, such
as personal computer network hubs, digital cameras,
programmable-logic controller networks and embedded Ethernet
controllers.
Another product that MRS has recently developed is a low-frequenstone crushing plant erection consultantscy
communication system that actually sends radio signals through the
earth for emergency evacuation of mining personnel.
The product line uses a unique method of signalling using a low
electromagnetic field that has a distinct advantage over
conventional radio.
The narrow-band low-frequency FM-modulated signal can penetrate
through miles of soil and rock to reach personnel in the most
remote shaft or tunnel.
It can be sent to a variety of receivers, including cap lamps,
vehicles, fixed remotes or portable remotes.
„If the personnel are using cap-lamps, for example, it will cause
the cap-lamp light to flash, thereby advising individuals of the
emergency,“ notes Morrell.
Known as FlexAlert, it was developed in Canada by MRS to replace
the commonly-used emergency evacuation method of stench gas.
„The problem with using stench gas is that it takes a considerable
time to penetrate all the tunnels and can therefore take up to an
hour to alert all personnel.
„Secondly, it has to be tested at least once a year and after it
has been used nobody can enter the mine until it has been
ventilated.
„This makes this method expensive, as there is a loss of production
for a shift or two while the fresh air is pumped back into the
mine,“ explains Morrell.
With FlexAlert the signal is instantaneous and it can be tested as
often as possible without any loss of production or downtime at the
mine.
„Although the initial investment is somewhat higher than stench
gas, FlexAlert eliminates the expenses resulting from loss of
production,“ he remarks.
Although the product was developed in Canada, the company is doing
further development work on the FlexAlert-type product locally in
conjunction with the CSIR.