MineTracer Making News, Saving Lives

Coal Mine Operator Control Room

 

Mines typically install the MineTracer system in one of two ways: Either 1) as a standalone C+T system with two-way text communications plus tracking, or 2) with leaky feeder for voice communications together with MineTracer tracking. In all cases MineTracer provides accurate and seamless “continuous tracking” for best-in-the-industry locating of people and machines.

 

Mine operators that already have or want leaky feeder capability for day-to-day voice coordination of their mines find that MineTracer is a perfectly suited tracking solution. MineTracer is being installed this way by Wholesale Mine Supply in some of the largest mines in the country. Another alternative is pairing MineTracer with a non-I.S. or non-redundant leaky feeder systems to have two-way voice capability together with MINER Act compliance. For any mine, MineTracer offers the alternative of the lowest price-point of any combination communications and tracking solution that is guaranteed to meet the MSHA PPL.

 

Due to the fact that MineTracer is a two-way wireless data mesh system with capacity for hundreds of communication nodes, it has more capability than text messaging and tracking. For example, every MineTracer system can incorporate built-in atmospheric monitoring, such as belt-line carbon monoxide monitoring. Mine engineers can constantly monitor methane concentrations throughout the mine via MineTracer and use the data collected to reduce over-designed ventilation power for cost savings. The very same network that performs MINER Act communications and tracking can enable AMS and many other mine management features. The industry standard term that is sometimes used to describe this capability is SCADA, Supervisory Control and Data Acquisition. The built-in SCADA capability of MineTracer offers a mine operator unprecedented ability to manage their mine for operational excellence. Venture Design has partnered with one of the premier expert companies in mine management software to enable these kinds of features.

 

MineTracer Access Point (with 48-hour battery) Transports Data Wirelessly

Mine operators can use MineTracer to secure SCSR caches and/or inventory individual breathers. Tools and high-value assets can be secured in the same way. By affixing an inexpensive miniature MineTracer tag to any asset, the MineTracer system software will automatically alert the dispatcher if it is ever moved or tampered with. And more capable machine-mount tags can be routinely placed on moving machines in the mines to keep track of the machine location and detailed parametric health status. By wirelessly tracking vehicle diagnostics or battery status real-time, and other operational parameters such as belt drive

amperage, belt scale tonnage, and roof stability, a mine operator can make decisions and create processes that improve operational effectiveness.

Having one system to manage all of this is a boon to mines that don’t need more of a maintenance burden. MineTracer has been operating reliably for over two and a half years in full-scale deployments in underground coal. The miners who work with the system every day have come to trust it. Superintendent Les Fox sums up his experiences this way, “I’ve never seen a system exactly like this one. The MineTracer system is easy to operate and it makes us a much more efficient coal mine in terms of productivity and how we manage our mine.”

 

For additional information or an in-mine demonstration, contact:
• Bill Hensler, Wholesale Mine Supply, (724) 515-4993 Ext 01
• Your local Fairmont Supply

Maximum effectiveness for safety and daily operations is achieved with high-accuracy, continuous tracking and 2-way communications availability for all miners at all times. Alternatively

MineTracer is easy to install, use, and maintain. Play the video in the web site below to hear from the people who use the system every day. MineTracer – the right thing to do.

For more information, call 509-232-8757 or 724-515-4993
http://www.beckerwms.com

Three of the exceptional strengths of wireless mesh systems for underground mining are (1) The ability to communicate information through mine entries/crosscuts without relying on wires of any kind; (2) The ability to adapt on-the-fly to a host of bad conditions that can happen in a mine, so as to survive and continue operating; and (3) For the special case of the Venture MineTracer wireless mesh system, the ability to operate tiny untethered readers on battery power in working sections to completely avoid the hassle of managing wires near the face.

A useful metaphor to describe how mesh wireless systems work is the simple bucket-brigade of old-time firefighters. If a couple dozen firefighters spread out between a water supply (on their left) and a burning building (on their right), they will behave much like a wireless mesh network passing buckets full of water to douse the flames (see Figure 1). If any one man in the bucket-brigade is injured or slows down (bottle-neck) the men around him can see that and automatically route some or all of the buckets around him to share the load. The end result is a highly adaptive system and a steady supply of water to the flames. The men can decide on additional useful actions on-the-fly as the situation develops. One example is that some of the men who are not passing full buckets from left-to-right can begin passing empty buckets back from the fire to the water supply (from right-to-left) so they can be refilled. And others in the group can help coordinate and supervise or send messages back and forth. This simple system illustrates much of what is going on in a wireless mesh system.

FIGURE 1 - Wireless Mesh is Like a Bucket-Brigade
In wireless mesh networks, each “reader” (sometimes called a node) is like one of the firefighters. The “reader”, just like the firefighter, has its own brain, knowledge, and wisdom of how to handle evolving situations and “still get the job done.” The wireless mesh readers pass information back and forth to/from other readers just like buckets in the bucket-brigade. The buckets in this case are filled with information. One bucket may be filled with the knowledge that “Joe is located near the #4 belt-drive.” Another bucket is filled with the information that “Tony needs help with a repair at the power center.” Another bucket is filled with the knowledge that “Methane concentration is 0.3% at the head-gate.” If any buckets are ever lost or damaged they are sent again at high speed.

So how does all this wireless communication take place in an underground mine, and why does it not require wires to carry it?

No Need for Wires; Adapt On-The-Fly: The mesh network “readers” are each separate radio repeaters (receiver plus transmitter located in the same device). These readers must be located in the entries and crosscuts so they are within radio range of each other (typically within 500-2000 feet spacing in the Venture MineTracer system). In so doing they are within transmit/receive range of each other so they can wirelessly accomplish the “relay of buckets.” Wherever a particular reader has a usable radio link to more than one other reader, an exceptional capability exists to route information around problems in a process called “self-healing” (in MineTracer we call this process “hop-over” and “orphan node adoption”.) An example would be a small roof-fall that destroys one reader. In that case, just like one of the firefighters becoming ill in the bucket-brigade, the wireless readers route buckets past the injured member to the firefighter just beyond or to the side of the injured one. Another example is the case of an explosion or major roof collapse that fills an entire entry. In that case, just like a situation in which a whole row of several firefighters becomes exhausted, the surviving wireless readers nearest the accident can reroute buckets (wirelessly via a crosscut with stoppings for example) around the exhausted group (entry blockage) to a fresh row of firefighters (readers) in the alternate entry. The reason that no wires are needed for any of this is that all the radio repeaters are within radio range of each other (including through stoppings etc.) and can send/receive packets of information wirelessly through the air and around equipment, vehicles, etc.

Incidentally, one piece of misinformation about mesh wireless systems is that “if one node goes down, the rest of the down-stream network is compromised.” This is totally false. The truth is that in a well architected mesh system, even in the worst-case destruction of several readers, or an entire set of entries being damaged for a couple thousand feet, the vast majority (>90%) of the Venture MineTracer underground mesh network will continue to operate normally for at least 48 hours after the accident. This means that all but the most severely affected areas of the mine will continue to have unaffected wireless coverage that continues to provide accurate location tracking and 2-way communications. Separately, in the immediate vicinity of the accident, the smart and adaptive networking of wireless mesh will use self-healing to restore as much of that locally damaged sub-network as possible. It is the best of both worlds. Firstly, the vast majority of the system is not vulnerable to single-points/single-zones of failure; and secondly, the sub-parts of the network that are directly inside the damaged zone will use self-healing to restore as much function at/near the accident-site as is possible.

No Wires Near the Face – Not Even for Power:
Wireless mesh systems in general share the strengths described above, but the Venture MineTracer system adds an additional set of totally unique capabilities that make it especially practical for working-section coverage. The recent MSHA PPL on this subject requires 200 feet location accuracy in working sections, together with continuous wireless communications coverage there. The MineTracer developers created a mesh system that provides 100% untethered readers for working section coverage; these readers run for many days on tiny rechargeable batteries so there is no hassle of managing wires in the dynamic working face environment. And the performance is just as good as everywhere else in the mine. MineTracer working section readers are housed in rugged fiberglass boxes smaller than a shoebox (less than 6 pounds), the antennas are omni-directional (every direction), and there are no exposed antennas or other parts that can be damaged. They can be operated for 4-12 days on tiny rechargeable batteries (see Figure 2).

FIGURE 2 - Untethered Readers with Tiny Multi-day Battery

Easy to Install, Maintain, and Use: For any wireless system to be effective it must be straightforward, easy to install, easy to use, and provide all necessary information clearly. Some wireless mesh systems like MineTracer perform exceptionally in all of these areas because the bucket-brigade nature of the communications makes it possible to operate entire underground networks with low voltage DC and very low power consumption. Even for operation of 48 continuous hours post-accident! Gone are the unfriendly requirements for dozens of AC power taps underground. Gone are the big power supplies and huge heavy batteries. And gone are the sensitive directional antennas that can be damaged or mis-aligned by bumping. All of those things bring costly installation and maintenance hassles, but well-designed mesh wireless systems eliminate the hassles. Mesh systems like MineTracer even offer additional features such as mine monitoring (AMS) and remote management that go well beyond MINER Act requirements for no additional cost.

 

Most mine operators in the industry will be driven by their values to find “the right thing to do” for their mines and their miners. Well-designed wireless mesh systems are one of the choices they have with some unique benefits.

Jim Barrett is the R&D Manager of the Venture MineTracer System, and has been managing the development of wireless systems for 28 years for Hewlett Packard, Agilent Technologies, and Venture Design.

MineTracer CO Sensor for Automated Belt-line Monitoring

About Two-way Text and Voice
MineTracer is a wireless mesh node network. The specific architecture chosen is very well-suited for survivability in the underground mine environment since communications can take alternate paths if necessary. One of the reasons that MineTracer performs so well and is so simple is that it implements wireless mesh technology in the straightforward way in which mesh is most robust. MineTracer uses two-way text communications quite deliberately for a number of important reasons. If one considers the realities of SCSR mouthpiece limitations and traffic jams of simultaneous voice calls during emergencies, it is clear that two-way text communication is the better choice for MINER Act safety systems. MineTracer’s implementation of text messaging allows all miners to communicate with the surface at the same time, even during the chaos of an unfolding event.

But some mines want voice for day-to-day communications and for those operations an excellent solution that works hand-in-hand with MineTracer is leaky feeder voice communications. In partnership with Wholesale Mine Supply, MineTracer is installed with Varis Leaky Feeder into mines that want day-to-day voice radio service. In such cases, MineTracer provides the tracking solution, but the mine can choose whether they want the Varis leaky feeder system to be their MSHA PPL-compliant communications system (in which case the leaky feeder is regulated as a safety system by MSHA), or whether they want MineTracer to be their MSHA PPL-compliant communications system. In the latter case, the leaky feeder can still be installed (or remain installed if it is already there) but the leaky feeder system is not held to the strict IS and PPL safety requirements of a MINER Act system. The leaky feeder system can instead be used for every-day communications with little regard for regulatory matters. This type of voice system works well for day-to-day voice coordination, even across very large mines and is well proven. In fact, some of the largest mines in the country are setting up their mines this way; with MineTracer as their PPL-compliant safety system, but with non-compliant leaky feeder as their day-to-day communications system. Incidentally, MineTracer can be deployed in similar fashion with any leaky feeder system from any manufacturer – old or new.

There is a huge difference in complexity between a multi-node mesh system that employs voice versus a mesh system that employs text messaging. In layman’s terms, a wireless mesh network transfers data packets like a bucket-brigade and can normally tolerate some dropped or spilled or delayed buckets and still deliver enough water (information) to quickly put out the fire. For the MineTracer system to properly communicate or track a miner the system only needs to successfully pass a single bucket (data packet) through the mine in a period of one minute (and many retries are allowed). Contrast this with the highly complex voice-over-mesh systems that must pass tens of thousands of sequence-ordered buckets across the mine every second, with no out-of-order buckets allowed, no delays allowed, and no chance for retries. In this way MineTracer is exceptionally engineered to avoid all the problems of the voice-over-mesh systems, while properly using the many unique strengths of mesh technology to achieve breakthroughs in simplicity, reliability, and low cost for underground communications and tracking in the mines.

Built-in Sensor Monitoring
On the subject of AMS or belt CO monitoring, it surprises some mine operators that the MineTracer system has already built-in the capabilities to meet regulatory requirements of MSHA for belt-line monitoring/alarming with no extra charge. More than just carbon monoxide and methane, too; MineTracer can automatically monitor many other parameters that a mine may want to measure to improve their operations and efficiency as well. Only the sensors themselves must be purchased as additional equipment. The strobes and audible alert devices, plus calibration and management software, are already included with MineTracer. This means that the financial outlay that a mine must make to comply with their MINER Act safety requirement also covers the cost of their belt monitoring infrastructure and software. Plus having only one system to manage for all of this is a boon to mines who don’t want more maintenance burden.

MineTracer CO Sensor for Automated Belt-line Monitoring

Asset Tracking
Mine operators have also discovered the value of using MineTracer for asset tracking and theft deterrence, even for items like tools and SCSRs. A miniature MineTracer tag can be affixed to an SCSR cache, or to a tool chest or other asset, and whenever the SCSR cache door is opened or the asset moves the MineTracer system software automatically alerts the dispatcher. Other machine-mount tags are routinely placed on moving machines in the mines to keep track of the machine location and status. Consol Maintenance Manager Kenny Morgan says “With MineTracer, when you see that you’ve got a piece of equipment broke down, you can look right on the screen and know who is there and their capabilities, and you can immediately make arrangements to get other people there if needed, and that’s all good stuff when you are trying to keep a mine up and running. It has big benefits for production.”

MineTracer has been operating reliably for over two and a half years in full-scale deployments in underground coal. The miners who work with the system every day have come to trust it.
Superintendent Les Fox sums up his experiences this way, “I’ve never seen a system exactly like this one. The MineTracer system is easy to operate and it makes us a much more efficient coal mine in terms of productivity and how we manage our mine.”

MineTracer was designed to provide accurate tracking and flexible coverage areas, and the system is MINER Act compliant for survivability and standby power capacity. The typical MineTracer System provides continuous or zonal tracking of miners and equipment along main travel entries, work areas, and escapeways. Miners have the option of wearing a tracking device called a Mobile Communicator which also has an emergency alert capability or a two-way Text Messaging Mobile Communicator with built-in tracking. Wireless Access Points (WAPs) collect and communicate location and message data via neighboring WAPs through the network up to the mine office. Three-color LED strobes on the WAPs are used to acknowledge messages sent and to signal section or mine-wide conditions or evacuation. The location of each miner is displayed on a map and in tabular form on a computer in the mine office. Location data for up to hundreds of devices and 28 miles of mine coverage is updated every 20 seconds providing constant safety monitoring of miners from the mine office. In the event of a mine accident, MineTracer will operate continuously on batteries for days after the power has been cut off to the mine.

In addition to monitoring miners and equipment, MineTracer can also collect and report fixed or mobile sensor data for gasses and air flow. Wireless sensors for CO, methane, CO2, and air-flow are available with the MineTracer system.

"We have a portable MineTracer demo kit that allows us to set up a mini-network in an office or mine," said Hensler, "We can demonstrate the system, user-interface, and show how easy it is to place the Wireless Access Points."

"MineTracer has proven its reliability at a reference site installation in West Virginia for over a year," said Hensler, "and Venture has continued to improve the system and recently received MSHA approval for longer range Wireless Access Points and extended standby performance."

Mine operators required to comply with the MINER Act of 2006 now have access to two- way wireless communications and tracking capability integrated into a single system. Maintenance for operators is simplified in that only one system needs to be installed and monitored.

"We've been using MineTracer for safety monitoring in our mine since August of 2007," said Mona Marcum, Safety Director for Southern West Virginia Resources. "I know where our miners are at all times. Now, we'll have wireless communications with our underground personnel."

MineTracer provides location information for miners and assets underground during everyday operations and more importantly provides continuous communications and tracking information for days in the event of an accident when power is shut off to the mine.

With the certification by MSHA, operators can install MineTracer systems with no contingencies (pending MSHA approval) attached. The West Virginia state functionality requirements and federal safety requirements have been satisfied for every component of the MineTracer system.

"MSHA's approval of the TMLT is an affirmation that the MineTracer development team's efforts of the last few years have been successful," said Ken Hill, Helicomm's director of sales. "We will now focus on integrating productivity features to help accelerate the return of a MineTracer investment."

The typical system layout provides continuous tracking of miners along main haulage entries and work areas. In the event of a mine accident, MineTracer will operate continuously on batteries for days after the power has been cut off to the mine. Additional communication and monitoring features will be seamlessly integrated and introduced over the coming months to further enhance the value of the system to mine operators.

With about one third of the country's underground coal mines, West Virginia has been leading the charge in evaluating communication and tracking systems. A MineTracer system has been installed and operating in Southern West Virginia Resources' Big Branch Mine since June 2007. The mine site has been the demonstration platform for interested mine operators and West Virginia legislators.

In addition to intrinsic safety testing and approval, MSHA engineers recently evaluated the functional performance of the MineTracer system at Big Branch. Engineers measured the wireless ranges of the system including the performance through stoppings and across belt lines and other obstructions. Exercising one of the most important capabilities of the system, MSHA engineers observed a seamless transition to backup battery performance after the MineTracer network was cut-off from AC power. Strobe lights on the Wireless Access Points were shown to have multiple uses including signaling mine safety status or evacuation. The large high-definition monitor in the mine office displayed the fluid movement of miners and equipment section-by-section. Venture engineers also demonstrated the MineTracer system's ability to transmit wireless mobile methane sensor data from the miner up to the mine office.

"The MineTracer system works well and with continuous tracking we know the location of everyone underground at all times," said Kenny Morgan, Big Branch Mine maintenance manager.

Choosing the right technology from the beginning was crucial for meeting the ambitious goals of the MINER Act which include wireless coverage, redundancy, and post accident serviceability. Venture opted for Helicomm's ZigBee-based wireless networking which enables very large, low powered, meshed networks.

"MSHA's approval of MineTracer represents a quantum leap for safety systems in the coal industry," said Ken Hill, Helicomm's director of sales. "It is truly bringing 21st century technology into the mines."

The system components normally will be interconnected with low-voltage DC power cables; however, in the event of an emergency, the power cables become de-energized, and the system will resort to battery power and can remain operational wirelessly. Although not yet incorporated in the design, Venture Design intends to add text messaging and gas detection to the system in the future.

Since 2006, MSHA has issued 36 new or revised approvals for communications and tracking systems, including a hand-held portable radio, several leaky feeder systems and several radio frequency identification (RFID) tracking system components. MSHA currently is examining 41 additional communications and tracking approval applications, including several wireless communications and tracking systems.

The Mine Improvement and New Emergency Response (MINER) Act of 2006 requires that each mine evacuation plan include provisions for tracking the pre-accident location of all underground miners. Furthermore, the MINER Act requires that mine operators adopt wireless communications and electronic tracking systems by June 2009.

MSHA's Approval and Certification Center tests a wide range of mining equipment, components, instruments and materials to ensure that they meet government standards for safe design and construction. This work helps to ensure that the various products will not contribute to an explosion, fire, electrical failure, vehicle crash or other kind of accident. The center, located near Wheeling, W.Va., houses laboratories, explosion galleries and offices that perform administrative work and recordkeeping

MineTracer is a fully integrated 2-way wireless communication and location tracking system designed to satisfy both local and federal regulations. The TMC enables all equipped miners to simultaneously maintain 2-way communications with the mine office where their location and messages are time-stamped and recorded.  Unlike voice systems, every miner can communicate with the mine office in parallel, and the digital technology provides a history to include the who, what, where and when of every message sent or received.

"We believe it's important for every miner underground to be able to communicate to the surface - especially during an emergency," said Ken Hill, director of sales, Helicomm. "This certification allows us to move forward with additional 2-way communication capability and continue our mission of improving mine safety."

MineTracer was included in the first group of approved products by the state's Office of Miners' Health Safety and Training on June 6, 2007. West Virginia required mine operators to submit initial plans for communications and tracking systems under legislative rule Title 56 Series 4 during Q2 2007. Final plans are being approved to meet the requirements of the new rules.

"The key accomplishment with this approval is to provide a communication and tracking solution in a single system. There will be no restrictions for use of the TMC device in any hazardous areas of any mine," said Eric Pirttima, business development manager, VDSI. "This technology provides a safer environment for the miners and peace of mind for their families."