About MineTracer
MineTracer is an integrated wireless communication and tracking system designed specifically for use in underground mines. MineTracer was developed to address the Federal MINER Act of 2006 and West Virginia Rules for communication-tracking performance. Every component of the system has been approved by MSHA for operation in permissible areas in coal mines (potentially explosive atmospheres).
The installed coverage area is flexible and a typical MineTracer layout provides unsurpassed 100% tracking and communication coverage along the haulage entries (alternate escapeways) with either continuous or zonal coverage on the primary escapeways. The MineTracer network is characterized by Wireless Access Points (WAPs) placed at entry/crosscut intersections every few hundred feet for continuous coverage on main entries. WAP spacing is dependent on entry roof height and undulation. Every few seconds, tracking devices worn by the miners report to the closest WAPs. The WAPs transmit location data wirelessly via neighboring WAPs to an area Subnet Controller which can be up to a mile away from the miner. Each Subnet Controller collects this wireless information from as many as 75 WAPs and transmits data up to the mine office via low-cost 12-gauge twisted pair wire backbone. The location of each miner is displayed on a map and in tabular form on a computer in the mine office. No matter how large the mine, miner location is updated every 20-30 seconds.
In a typical mine, only two or three Subnet Controllers are needed to support several miles of entries monitored by the Wireless Access Points. The Subnet Controllers are connected to a backbone loop up to the mine office. Communication on the backbone loop is bi-directional so if the loop is broken in an accident, location information is redirected to the mine office through an alternate route.
For 2-way communication, the MineTracer system uses text messaging rather than voice. This is very important as it allows every miner to communicate to the surface at the same time during an emergency event. Each miner's location and message is time-stamped and recorded in the mine office. The Text Messaging Mobile Communicator (TMC) worn by every miner has a 4-line LCD display and 256 message menu — plenty of capacity for both operations and emergency messages. Custom messages are programmable for each mine. The TMC is also the tracking device. Miners are alerted to new incoming messages via the ringer and a bright flashing LED on the TMC.
Mine operators have the option of deploying
MineTracer for tracking-only service by using the Mobile Communicator
(MC) tag shown here. MCs are equipped with an emergency alert button.
When pressed, the dispatcher in the mine office is notified immediately
of the miner's location and need for help. The dispatcher can
acknowledge the alert message and notify others in the area via LED
strobe lights on the Wireless Access Points. Mobile Communicators are
MSHA IS-approved for use anywhere in the mine and have a two-year
battery life.
Since the range of a Mobile to a WAP can often be as far as 700 feet, in practice the Mobiles are monitored by multiple WAPs. The figure below shows a typical representation of the MineTracer components on a mine map section with 100% track entry coverage and zonal coverage on the primary escapeway.
Choosing the right technology from the beginning was crucial for meeting the ambitious goals of the MINER Act. MineTracer is built upon the IEEE 802.15.4 wireless communication standard and uses low-power 10mW digital radios operating in the UHF band. IEEE 802.15.4 defined by the Institute of Electrical and Electronics Engineers enables large, medium-rate, wireless mesh networks.
The low transmission power is one of the keys of the MineTracer system. Low power translates to keeping Wireless Access Points intrinsically safe so that the system can operate in both fresh air and permissible areas. The system's low power usage also allows MineTracer to be operated on battery power for a long time in the event of a power shutdown in the mine. When the AC power goes down for any reason, MineTracer can still monitor and locate miners for at least 48 hours on battery power.
MineTracer was designed for industry leading reliability and survivability. If one or more Wireless Access Points are damaged in an accident, the MineTracer network remains largely operational since only a portion of the system's wireless communication will be blocked. Neighboring WAPs and networking functions remain in service. The mine office is notified immediately in the event of any WAP or network failure.
MineTracer goes beyond communication and safety tracking to help manage mine operations more efficiently. In addition to monitoring miners and equipment, MineTracer can also collect and report wireless sensor data for gasses, temperature, water level, and air flow. These measurements are a natural extension of MineTracer's monitoring capabilities that will help keep miners safe.
To learn more about MineTracer or to see the system in operation, please contact us!