Proximity awareness in action with Mine Site Technologies. Through the implementation of MST’s proximity detection, a customer focuses on improved safety of haul truck and loader operations near personnel, light vehicles, and other heavy vehicles.
In general the goals for any underground mine’s communication system are improved local and global communications within a system that is simple to use, improving health and safety. One important direction in which this is all moving are comprehensive systems that embrace people, machines, service and monitoring. MineTrax is an example of such an embracing system. Its implementation at Fresnillo’s La Cienega mine in Mexico began in 2011.
Fresnillo’s Chief Information Officer, Baldomero Gutierrez says “MineTrax is truly a breakthrough technology since, to my knowledge; it is the only underground system with wireless network infrastructure capable of lasting several years on a few small batteries.”
Newtrax Technologies, a high-tech company based in Montreal, Canada, is in battery-powered wireless networks for tracking, texting and telemetry in environments where the installation of wires for power and communications is problematic. MineTrax is its networking platform, purpose-built for underground mines and in collaboration with several mining application specialists, a comprehensive portfolio of solutions to improve safety, productivity, condition-based maintenance and energy management is offered.
Gutierrez cites “safety benefits that include early warnings of health and safety hazards, including poor air quality and ground instability; emergency two-way communications in production areas and after a cave-in or fire, even in the hard to reach last mile of tunnels; faster rescue operations via real-time location information on miners trapped underground. Productivity benefits include automated data collection and reporting, real-time operational intelligence (enables better mining process optimisation), and early warnings of maintenance problems (increases total uptime of production machinery). Environmental and social benefits include lower energy consumption by turning off ventilation in areas of the mine without active diesel machinery or personnel; continuous monitoring and logging of operating parameters enable verification of compliance with commitments; better competitiveness means better chances of maintaining jobs even at low commodity prices.”
The simplicity and backward compatibility of the MineTrax system is valuable, with a network infrastructure consisting of wireless, battery-powered and self-organising nodes designed to last years on a few small D cell batteries. MineTrax can also internetwork with both narrowband (e.g. leaky feeder, through-the-earth) and broadband (e.g. fibre, coaxial) backhaul links to the surface, providing greater flexibility and adaptability to heterogeneous mine sites.
Several cap lamp manufacturers, including Jannatec Technologies, have integrated MineTrax wireless modems in their cap lamps to enable miners without radios or in fringe areas without leaky feeder coverage to receive evacuation notifications, request help, receive free-form text messages, respond to multiple choice questions, initiate the transmission to surface of precanned text messages from a drop-down list (for example to periodically confirm everything is OK). When combined with the MineTrax postaccident network probe, the MineTrax cap lamp modem also enables miners underground to exchange text messages with the rescue teams on surface after a cave in, fire or other accident disabled the leaky feeder system.
MineTrax architecture
Through-The-Earth (TTE) technology has merits as a post-accident backhaul and MineTrax networks can use it as an alternative to leaky feeder, fibre optic or twisted pair for backhaul links to surface. The simultaneous use of several different types of backhaul links is advisable to maximise the probability of at least one backhaul link surviving any accident. The MineTrax network is self-healing, and so will automatically re-organise itself to send/receive data from surface via any backhaul link available.
The MineTrax Post-Accident Network Probe (PANP) is an alternative to TTE to achieve the same objective: post accident two-way backhaul communications from an isolated area underground to surface. Newtrax says “the difference is that the PANP is a lot simpler and cheaper than TTE, it supports a higher bandwidth and has no maximum depth limitation: via a ventilation shafts or a 51-mm bore hole, mine rescue teams can drop down the PANP via a cable and let the network underground re-configure itself is such a way as to use this ‘new’ backhaul link to surface.
Several PANPs can also be installed preemptively (instead of reactively) close to active areas to create additional permanent backhaul links to surface, effectively increasing the probability that at least one backhaul link will survive. If at least one backhaul link survives in a post-accident isolated area, the system won’t experience any downtime. Some of the other advantages reported by Newtrax include: Everybody underground is able to add, move or completely relocate network nodes dynamically; 915/868 MHz frequency hopping RF enables wireless nodes to provide the best non-line-of-sight coverage; sensors are also battery-powered repeaters, effectively increasing the number of nodes in the mesh network and therefore its resiliency; should an area of a mine become isolated after a collapse, communications can be reestablished by dropping a network probe down a bore hole; open architecture to interface with third party applications.
The battery-powered wireless networking technology provides a reliable and cost-effective solution for mobile data communications and RFID tracking in environments where the installation of wires for power and communications is problematic, including production areas close to the face.
MineTrax can provide the operational intelligence required to optimise production processes like the location of all mobile equipment and personnel, the number of loadhaul-dump cycles, payload carried and time spent idle. The system, which leverages vehicle data loggers and sensors manufactured by ISAAC Instruments Inc., can also provide the maintenance team with real-time alarms as triggers for condition-based preventive maintenance: Excessive rpm, high engine coolant temperature/low engine coolant level, high engine oil temperature/low engine oil pressure, high transmission oil temperature/low transmission oil pressure, low hydraulic oil level, hour meter.
For the dispatch of production equipment based on location, availability and status, onboard computers allow mine vehicle operators to manually input machine status information and receive instructions.
In previous articles we have considered VOD (ventilation on demand) and how it can save energy wastage. MineTrax is the recommended tracking and telemetry platform for Simsmart VOD software, which needs an openarchitecture platform for real-time tracking of personnel and machinery, telemetry of diesel and electric/hydraulic engine status, telemetry of gas concentration and air flow, texting of warning messages to personnel entering areas with bad air quality, and remote control of auxiliary fans and air flow regulators. Similarly, pumps can be remotely monitored and controlled.
It is often impractical to extend leaky feeder systems to the farthest working areas. Furthermore, extending the leaky feeder close to the face can result in frequent blast damage which then often leads to mine-wide system downtime/imbalance. MineTrax battery-powered wireless networks are a solution for use in these extremities of a mine. Everybody underground is able to add, move or completely relocate network nodes dynamically. Only one component is required to extend coverage, the battery-powered wireless infrastructure nodes – no wires, no connectors. Local damage does not cause mine-wide downtime. Remote diagnostics tools from surface quickly identify the location of any damaged node.
After a cave-in or fire, backbone network cables may be cut, likewise power lines may be cut. The location of personnel just before the accident may be unknown and it is almost certain that the location and health of personnel after the accident is unknown. Air quality after the accident will also often be unknown. So, with conventional communications systems, there is no way to communicate between personnel trapped underground and rescue teams. Once underground, rescue teams will be unable to communicate with other first responders on surface. MineTrax battery-powered wireless networks can provide two-way texting, tracking and telemetry after an accident. Isolated sections of the MineTrax network will continue to operate. If at least one backhaul link was preemptively installed in the isolated area, the network will self-heal and connectivity to surface will be maintained without any downtime. If no backhaul links to surface were preemptively installed in the isolated area, postaccident network probes can be dropped down 50-mm boreholes to create new backhaul link options. The isolated networks will self-heal and connectivity to surface will be re-established.
Ground stability monitoring is essential to avoid cave-ins but manual data collection from instruments is time consuming and cannot provide real-time alarms. Often power and communication are not available in production areas or wires are not reliable. Again, MineTrax has a solution. It enables a new generation of battery-powered wireless instruments for geotechnical applications, and/or air quality monitoring designed for permanently fixed installations with a battery life of several years. Each instrument is also a wireless repeater/router and therefore extends network coverage. Self-organising and self-healing multi-hop wireless networking capability enhances the overall network reliability. MineTrax gas detectors are supplied by Conspec, and the geotechnical instrumentation by Mine Design Technologies (MDT).
Some mines build their own systems, like Chelopech in Bulgaria (IM, October 2011, p16), which used readily available equipment, mainly from CISCO and AeroScout. AeroScout’s active RFID tags and/or standard wireless devices send a tiny wireless signal at a regular interval. That signal is received by the Wi-Fi wireless network (or location receivers), and is sent to an AeroScout Visibility Engine. Microsense industrial controllers are also an integral part of the system. Having built this system, Chelopech Mining was one of three top finalists for the CISCO Innovation Awards 2011 in the category: Most Innovative Business Impacting Network of the Year.
Don’t get too close
Following extensive evaluation and trials of various options for vehicle proximity detection systems to be installed on its underground mining equipment, a major mining customer in South Australia has selected the Mine Site Technologies (MST) proximity detection solution for its vehicle and personnel proximity technologies initiative. Included in the solution is the use of MST’s ICCL (Integrated Communications Cap Lamp) with integrated RFID tracking tag and text and emergency messaging technology – messaging is sent to mine personnel using Mine Site Technologies’ PED through-the-earth communications system.
A primary focus for the customer is the safety of their personnel. In a statement issued by the customer they highlighted the fact that “the goal of this particular project is decreasing vehicle to vehicle and vehicle to pedestrian interaction”. Through the implementation of Mine Site Technologies’ proximity detection, which includes inner zone detection from Strata Proximity Systems, and ICCL communications options, the customer focus is on improved safety of haul truck and loader operations near personnel, light vehicles, and other heavy vehicles. They will also collect the interaction data for ongoing risk identification and minimisation. In addition, use of the ICCL provides several safety benefits including the use of PED paging which provides a second means of personnel notification in the event of an emergency.
Installation and implementation of the Mine Site Technologies’ proximity detection system commenced in early 2012 and will be completed for full implementation mid-year. Replacement of existing cap lamps with the new ICCL’s will coincide with the installation and implementation of the proximity detection equipment. All cap lamps, checking stations, operator and support training will be completed and all systems are to be operational mid-2012.
Lloyd Zenari, CEO of Mine Site Technologies, stated, “The customer’s selection of the Mine Site Technologies proximity solution is yet another acknowledgement of the effectiveness of our mining purposed communications and tracking solutions. We focus on providing solutions which enhance safety and productivity – the two top priorities of our customers worldwide.”
Mine Radio Systems (MRS) has recently completed testing of its widely anticipated collision warning technology. The Solarian system has been implemented in two large mining facilities, one in Europe and the other in Brazil. The facility in Europe has multiple Solarian beacons, all equipped with flashing lights and buzzers. The facility in Brazil has a similar configuration. The system underwent testing for three weeks and positive results from the trials have set in motion negotiations for an order of 200 units over the next two years.
“Our Solarian units have had excellent results at all of our test sites,” said Cindy Chesney, MRS General Manager, “While the system can stand alone, the key to our success has been the solution’s seamless integration into the existing communication backbone.”
The MRS Solarian solution, in addition to warning of impending danger, can collect vital tracking information from personnel and vehicles within a predetermined danger area and place this information into the INsite® database. The Solarian solution uses two units for monitoring and tracking- a beacon for receiving the ID from vehicle and personnel transponders and the display unit that displays the ID received. When a transponder is in the danger area a visual and or audible alarm is raised to notify the operator or personnel of impending danger. The Solarian Solution also works seamlessly with MRS INsite® software allowing access to information for report generation and management. System summary:
¦ Collision Warning
¦ Integrated asset tracking
¦ Transponder ID display
¦ Basic and supervisory vehicle lockout
¦ In vehicle LCD display unit
¦ Driver bonding
¦ Transponder count display.
“When designing the Solarian system we took into account; typical collision scenarios, visual hazard identification, human error and fatigue, and the ability of the system to integrate with existing communications systems. Backed by MRS 25 years of in the field communications experience we feel that Solarian will quickly gain the industry’s confidence.” said Ken Morrell, President of Mine Radio Systems.
MinLog has engineered a solution designed to overcome the challenges of communication and availability, at the same time reducing the amount of operator interaction required. This solution is a departure from traditional closed systems using LEDs and purpose-built displays to on-board tablets. The MineSuite FMS offering innovates by means of an integrated Proximity Awareness module running off the same Windows-based MineSuite FMS tablets, responding to tags that make use of either RFID or WiFi communication technology.
Minlog’s proximity model
The company explains that “RFID tags operate at the 433 Mhz frequency, delivering pulses every one to five seconds. These are cost effective and reliable with a battery life of up to ten years and typically associated with implementation requiring the minimum amount of infrastructure. Their limitations are in their detection range: which averages 50 m, and the impracticality of their use when personnel are a factor. Wireless (WiFi) tags operate at a frequency of 2.4 Ghz, pulsing every second. They are typically powered by the power source on the device or machinery to which they are mounted, such as the mining personnel’s caplamp. Detection ranges underground are up to 100 m. This technology will allow for future requirements such as humidity monitoring, automated muster check-off and zone management.
“Though the WiFi based systems are generally associated with a greater requirement for infrastructure a further advantage of WiFi over RFID technology is that it allows for the establishment of an inner zone around the HV where personnel will be detected the moment they enter the inner zone.
“Furthermore, with all personnel tagged, it is possible to obtain data around the use of refuge chambers in a particular zone of an underground environment. Once the number of people in that zone has been exceeded, an alert can be sent to the control room. This information can also assist with a ventilation plan, either enabling improved ventilation or identifying unutilised areas where it can be turned off to save costs.
“The MineSuite FMS Proximity Awareness module requires the minimum amount of operator intervention, issuing alerts without any Operators’ interaction. The alerts are both audible and visible and can be changed to differentiate between the type of hazard (i.e. a different sound for HV (heavy vehicle), LV (light vehicle) and personnel). The operator can then associate the alert with the appropriate action required as quickly as possible.”
MineSuite also integrates with a video camera mounted on the HV. Operators can tap the tablet screen to bring up the camera image, a useful feature when checking blind spots either as part of procedure or when a proximity alert is raised. MineSuite combines the cameras with the production information and proximity awareness system instead of providing a camera installed with a purpose-built display.
The MineSuite FMS Proximity Awareness module also provides for extensive reporting and analysis abilities via the MineSuite MIS offering, for the identification of hotspots and the extent of movement of people around the mine.
Minlog’s Karel Gilliland explains “we are currently in the process of implementation at BHP’s Olympic Dam operation and have installed at Evolution’s Cracow operation (two differing configurations effecting similar, though different, results for differing requirements).
“We are excited as to our offering and have constructed it in a fashion to not only cater for safety but to ensure that operations are not hampered but supported, we have aligned it with our Production Monitoring and Management platform and it can be scaled and supplemented to form part of our Fleet Management and Production Management Information Solutions. “We have minimised reliance on infrastructure and this has made it as operator un-intrusive as possible.”
Following implementation of the MineSuite FMS Proximity Awareness module, Cracow conducted a survey of equipment operators who indicated that collisions are most likely to occur when machines are backed over in a stockpile, when leaving a level and entering the decline or coming around a corner.
The system was generally well accepted and is perceived by most operators as a worthwhile safety aid since 50% of the time vehicles detected were out of sight. The average detection distance was 40 m.
Communicating seismic information
Adam Dulmage says MDT’s top two products are the SMART cable bolt and the MPBX. By measuring the stretch of a cable, the strain between the SMART anchor locations can be determined, and the corresponding load inferred. These field-proven instruments allow optimisation of ground support, enabling costeffective excavations at greater depth, while ensuring the safety of equipment and personnel.
“Since its introduction in 1998, the SMART MPBX (MultiPoint Borehole eXtensometer) has revolutionised the extensometer market for geotechnical applications, making Mine Design Technologies a world leader in this field,” Dulmage says. It is a flexible borehole extensometer with up to six anchor points and an integrated electronic readout head. The sensor and head are small enough to be recessed into a 50 mm diameter borehole.
ESG Solutions has released its next generation PaladinTM microseismic recorder. The Paladin IV 32-bit digital seismic recorder is the backbone of ESG’s microseismic data acquisition systems which monitor induced seismicity during underground and open-pit mining operations. Designed for versatile signal acquisition, this low noise device records microseismic signals from a range of seismic sensors and transmits time-synchronised data via Ethernet to a central location for processing and analysis. The Paladin IV introduces plug-and-play functionality for improved ease of use, and remote diagnostics capabilities keep tabs on sensor health, allowing for quick system maintenance. Coupled with web-enabled global data streaming, powerful new on-board processing enables stand-alone units to perform advanced triggering and analysis without a PC, supporting a diverse suite of new remote monitoring applications.
A typical microseismic system is made up of a group of seismic sensors (geophones and/or accelerometers) distributed throughout a mine in a strategic array of underground and surface locations. The connected ESG Paladin digital seismic recorders receive and digitise seismic data relating to individual events before transmitting to surface stations for analysis.
As mines extend deeper, increased stresses or major geological structures can lead to damaging seismicity in the form of rock bursts, rock falls or fault slips. Seismicity is common in mines and is often heard as a popping or cracking sound as the rock shifts and attempts to redistribute stress caused by excavation. It is essentially the sound of rock breaking and is measured on a micro-scale at levels equivalent to very small earthquakes measuring from -3 to zero in magnitude. Identifying the location and size of these microseismic ‘events’, and evaluating seismicity temporally and spatially as it relates to operations serves as an essential tool to quantify and understand stress-induced rock mass behaviour. Incorporating the results of microseismic analysis with existing geotechnical tools provides some of the best possible information to influence short term and long term processes. Using microseismic results, operators can assess abnormal seismicity and rock mass response and take action to deploy workers in less hazardous regions of a mine, adjust ground support requirements or modify extraction methods or sequences to better manage seismicity and improve overall mine safety.
ESG’s continuous monitoring systems are set-up to essentially make a video recording of seismic activity throughout the mine. Unlike many other monitoring tools which take individual measurements at one location in a mine, microseismic monitoring is designed to cover a larger area of interest and function continuously so no seismic activity is missed. Often, the sensitivity of the system is such that seismicity is recorded from surrounding zones that were not intended to be monitored, but can reveal unknown conditions or seismic risk.
Since this monitoring reveals information about what is happening behind walls and in areas not accessible to mine workers, it can operate as an early warning system for potential hazards caused by changing rock conditions. If a system is installed early in a mine’s life, there is an opportunity to collect backgroundlevel data on seismicity in the mine. Since every mine generates some seismicity, it is useful to understand what is normal and what may be cause for concern. Microseismic systems can provide far-field observations of mine seismicity, help develop re-entry protocol following large events or blasting, alert operators to abnormal seismicity, help optimise ground support design, and calibrate or confirm numerical models used for mine design and sequencing.
Booyco Electronics has its Intelligent Whistler to boost safety underground – a signaling device that operates between an underground vehicle and a guard, incorporating an operator ‘whistle’ worn around the guard’s neck.
Anton Lourens, Managing Director of Booyco Electronics, says the technology was developed at the request of a customer and, based on its beyond-expectation effectiveness, is now being introduced to the mining industry at large. “The system is compatible with all makes of controllers currently in use in South African mines,” Lourens says. “It’s programmable to each mine’s specific requirements, in terms of preferred language or pictoral commands, and can be applied in a variety of applications underground, well beyond that of a Loco Signalling Device (LSD) function. Because it builds on existing technology, the Intelligent Whistler is also cost effective, readily acceptable to users and requires little additional training.”
The system is modular in design and harnesses radio frequency (RF) technology as a communication medium, allowing loco drivers and guards to communicate clearly and effectively with each other. These instructions are transferred in a radio data format that is displayed both at the fixed loco controller unit and at the portable ‘whistle’ unit. “When the driver needs to perform a specific task, such as moving forward, reversing, stopping and making an emergency stop, he informs the guard of his intention by simply pressing a button with pre-defined functions, customised to the particular requirements of that mine,” Lourens says. “Conversely, the guard communicates with the driver by blowing the whistle with a predetermined number of blasts.
“At the start of each shift, for example, a guard uses his whistle and ‘pair’ – a connection to the relevant LSD controller unit on the loco assigned to him – to create a closed loop system that eliminates external interference. The nature of the LCD system makes for a very user-friendly scenario and includes an LCD display and buzzer on both units. There is full data confirmation and acknowledgement of each instruction between the operator and the guard.”
The controller unit has I/Os that can be used to support a Fail to Safe philosophy and as an additional indication in the event of emergency stop instructions. The system operates in the 2.4 GHz frequency, with typical communication pairing ranges of up to 60 metres. The whistle unit is operated by a rechargeable battery with up to 12 hours of power. “A significant benefit of this system is that it provides access to data recorded in the event of an accident,” says Lourens.
More WiFi
Strata MSHA approved VoIP phone
Strata Worldwide says its StrataWiFi “brings the same wireless communications and productivity tools to underground mining that previously were only available on the surface. These including Voice Over IP digital voice, access to company networks and access to the Internet. Strata offers three different access points that all work co-operatively: 1. Non-intrinsically safe access point with external power and fibre 2. Intrinsically safe access point with external power and fibre, plus optional battery backup 3. Intrinsically safe, fully wireless access point with battery power.
“StrataWiFi only uses intrinsically safe hotspots in the working areas where they are required. Non-intrinsically safe hotspots are used wherever possible to help control costs.”
StrataWiFi uses the standard 802.11 specifications for wireless networks. This allows compatibility with a wide selection of consumer communications equipment, as well as compatibility with future networks and devices. Mines can choose from a variety of device manufacturers, including Strata partners.
StrataVoice, a Voice Over IP technology, allows private calling, calling to outside landlines, point-to-point calling, and broadcast voice messages. Workers underground can communicate with each other, colleagues on the surface, and the outside world. StrataData uses StrataWiFi to allow mines to bring data to wherever they need it. Workers can use almost any WiFi-enabled device such as notebook computers, tablets or smart phones to access data. is an underground network of fixed CommNodes that communicate with individual miner-worn communication devices to transmit two-way data between the surface and underground. The self-forming, self-healing routing system requires no hardwired backbone.
CommTrac provides continuous tracking within 15 m mine-wide, showing breadcrumb tracking and direction of travel. Two-way text can be either individual communication or broadcast messaging with freeform or canned responses. These messages can be sent to surface, surface to miner or miner to miner.
Just as CommTrac tracks the safety and whereabouts of miners, Strata Worldwide’s Asset Tracking provides tracking on critical assets, including vehicles and machinery. Asset Tracking is a simple CommTrac upgrade or quick one-day installation. Simply place a battery operated CommNode on a piece of machinery for immediate location and productivity data.
Partnering with Ultra, Strata Worldwide is offering a TTE communications with the RockPhone. It uses electromagnetic waves to transmit text and voice messages between the surface and underground. Two-way voice messages reach up to 200 m through the earth, while text messages reach up to 300 m. The system can be portable or stationary; batterypowered or powered by cables. It is ideal for post-accident communications and day-to-day communications between mine layers and the surface.
Vital Alert’s CanaryTMLink products provide a flexible wireless TTE link that can integrate with and complement other technologies covered in this article, as well as existing mine networks. Sandi Jones, VP Marketing & Technical Sales, Vital Alert Communication, says CanaryLink, “integrates nicely with the types of solutions covered in this article to extend their coverage and provide an always-on, ready to go connection post emergency.” CanaryLink TTE CommunicationT systems provide a flexible link that was designed to integrate easily with existing and innovative systems in the mine. Instead of creating a couple of end-to-end stand-alone solutions, Vital Alert created a flexible link that can work with both voice and data, integrate with tracking systems as well as with standard UHF and VHF radios, sensors, remote relays and many others.
A miner with a Vital Alert CanaryLink
Vital Alert offers three versions of the product, depending on the mine environment. CanaryLink can be mounted permanently but with a terminal weighing less than 6.8 kg it can also be relocated easily as work moves further into the mine. CanaryLink -IS (launching in late 2012 when MSHA certification is complete) is Intrinsically Safe, “but,” Jones says, “still more easily moved at 200 lb [91 kg] than other IS TTE alternatives. CanaryTMGo was designed for quick deployment in emergencies or temporary work areas. All three products deliver real-time twoway voice through up to 1,000′ [305 m] of solid rock, whether that is from the mine to the surface or between underground areas where there is no line-of-sight.
“CanaryLink products can act as primary link for specific use cases but are more likely to be used as backup during an emergency or outage, or as a temporary link where permanent network hasn’t yet been deployed. [It] can deliver communication where there is no hole and put trapped miners instantly in touch with rescuers where it has been pre-deployed (e.g. at shelters).”
While the range of is currently just over 300 m, it can equip deeper mines in three ways: 1. Repeater mode launching in 2012 allows for multiple CanaryLinks in sequence to cover a greater range. 2. CanaryLink installed between active work areas and networked areas higher up that are likely to be intact after an explosion or cave-in. 3. Providing horizontal links inside the mine (areas hard to reach or prone to damage).
To date, Rajant has shipped over 1,000 BreadCrumb UX-2400s to MST for the underground coal mining industry in the US. It is suitable for hard rock mines also
Rajant offers a family of proven and dynamic wireless network nodes, known as BreadCrumbs®. Proven Rajant innovations have led to a successful partnership with MST, which provides a purpose designed network communications platform to ensure that an underground mine’s overall communication system not only meets safety requirements but enables optimum productivity from all of its mining assets.
The company recently integrated Rajant’s rugged and dynamic BreadCrumb UX-2400 Portable Wireless Mesh Network Node to its platform. The BreadCrumb UX-2400 is ideal for use in underground coal mines, as it is a permissible AP and has received approval from the US MSHA for use in hazardous locations.
Rajant says “numerous BreadCrumb UX- 2400s have been deployed in underground coal mines since the partnership began. The nodes are typically placed along active mining areas in order to eliminate the need to run composite cable across active operations. As a reliable wireless-to-wired bridge, UX-2400s have helped extend the existing communication network beyond the furthest wired access point.
“BreadCrumb UX-2400s are completely portable and allow for communications and tracking capabilities to take place throughout a complex room-and-pillar environment. This includes areas where workers are actively cutting horizontally for coal. The combined solution has also benefitted longwall operations.”
System security
Cattron has released its high performance SIAMnet Diagnostic System (SDS) for its SIAMnet underground communication system. “Installed with virtually no interruptions in service, the SDS allows a problem to be rapidly diagnosed and downtime to be minimized,” Cattron says.
The system monitors every SIAMnet amplifier and reports status information on a periodic basis. In the event that an amplifier is faulty or operates outside of the set parameters, the mine technician can see exactly which amplifier is causing the problem without travelling into the mine. By interrogating the system through the SIAMnet Diagnostic Manager software, issues such as a power outage, damaged coaxial cable, low supply voltage or weak signals can be identified. Should an amplifier report abnormal conditions, an alarm is generated locally and an email is sent to the contact list.
While monitoring information is available to all users, the configuration screens are password protected and reserved to the administrator of the system. A web page, with current system status, may be made accessible from any location worldwide by the mine network administrator. The mine technician can get access via a secure Internet connection and troubleshoot the SIAMnet remotely. Should it be required, a service technician may be dispatched directly to where the fault is located.
The SDS is also useful in calibrating a SIAMnet network. Once installed, the amplifiers can be configured remotely to match the exact mine configuration. “A perfectly configured SIAMnet optimises the data rates while the voice communication audio quality remains exceptional,” Cattron explains. The amplifier configuration and alarm files may be kept for reference and further analysis.
The SDS includes a basic spectrum analysis feature and can display the signal strength over the entire 800 MHz band as well as the cable modem band. Although it does not replace an expensive spectrum analyser instrument, the SDM can identify RF noise issues and display signal strength in a graphical way. Should a thorough analysis of the SIAMnet be required, every amplifier has the possibility to generate test signals which can be used for troubleshooting. These features will help maintain a system without investing in expensive tools and expertise.
Logistic communications
In the southwest part of the Upper Silesian coalfields, Polish mining company JSW operates six shafts that deliver about 13 Mt/y of bituminous coal a year, of which about 70% is high-quality coking coal. In co-operation with Becker Mining Systems, JSW’s Zofiówka mine has been extensively modernising its underground material transport system and the communications associated with that for the past few years. The objectives are: 1. Movement from the area near the shafts with subsequent, interruption-free transport to the operating points on site via material handling stations. 2. Introduction of floor-mounted duorail systems or monorail systems with increased drive output and hill-climbing ability, with special suitability for heavy-duty transport and constructive design under observance of the safety regulations of the new European Machinery Directive 2006/42/EC. 3. Optimisation of the logistic processes through the tracking of vehicle locations, possibility of switch remote control through an aboveground transport control room, and a bidirectional voice connection to the vehicle drivers via WLAN and fibre-optic VoIP technology.
As part of this modernisation program, dieselpowered monorail locomotives from Polish subsidiary Becker Warkop were first introduced in 2007 already. Then came five units of the KPZS-148, with a motor output of 148 kW, a maximum tensile force of 100 kN per drive, and the ability to be used on inclines up to 30° from 2010 on. Along a current distance of 8.5 km, six EHB KPCZ 148 diesel-powered monorail locos operate in the mine.
The mine’s material logistics are supported by the setup of a WLAN network in a main haulage drive of the mine, where Becker Mining Systems’ newly developed, intrinsically safe access points (WRAP 200), with connected transmission cables (leaky feeders), act as transmission/receiving antennae and establish the wireless connection between the dieselpowered monorail loco and the mine-wide fibreoptic network. Through the latter, voice, machine data, and respective vehicle locations are transmitted to the aboveground control room via Ethernet.
For this purpose, the monorail locomotives are equipped with an intrinsically safe Mining Master Smart mini computer, which acts as a subscriber of the WLAN network and communicates with the access points through a machine-side gateway. Further, the diesel-powered monorail locomotive driver has the opportunity to set up connections to the telephone exchange using a mobile VoIP telephone so current information is exchanged with the control room and new driving instructions are transmitted. IM
