Agencies Consider New Products for Mining Applications
October 01, 2007
Mine Safety and Health Administration (MSHA), the U.S. federal agency responsible for the health and safety of miners, is looking at several wireless products to boost communications in mines. Radio Frequency Systems (RFS) executives say its foam-dielectric coaxial radiating cable, Radiaflex, is one of the first radiating cable products to meet the new 2006 mining technology requirements and obtain MSHA certification.
New mining communications systems and their components must be certified MSHA approved to comply with the latest U.S. mine-safety requirements. “The cable was subjected to a month-long qualification process to certify that it possesses advanced fire-retardant characteristics, crucial for mining applications,” says Suzanne Kasai, RFS U.S. business development manager.
Pillar Innovations recently paired with mining automation and communications system provider, Becker Electronics, to develop turnkey wireless communications systems for some of the largest U.S. coal mines, including one of the country’s largest longwall coal mines, located in Pennsylvania. The system is based on a combination of passive and active RF technology and is founded on RFS’ cable.
LANL staff operates an underground radio unit
while 97.5 meters underground.
Radiaflex also supports UHF spectrum, company executives say. The broadband nature of UHF communications enables the transmission of voice, data, and video. UHF systems also allow users to seamlessly upgrade to wireless LAN (WLAN) services, which will become increasingly prevalent in mining applications, executives say.
RFID Wi-Fi Technology
In addition, Active Control Technology (ACT) is seeking U.S. federal regulatory certification of the second core component of ActiveMine, a two-way voice communications and locating system for mines with a 100-percent wireless Wi-Fi network. ACT filed documents with MSHA for certification of its active RFID Wi-Fi tags, a component that enables accurate, real-time people and asset tracking.
MSHA is reviewing an application submitted in April for the system’s wireless mesh node modules and battery backup, which form the backbone of the ActiveMine wireless network. ACT executives in September applied for MSHA approval of ActiveMine’s Wi-Fi voice and data communications handsets.
The active RFID tags, which can be carried by people or attached to high-value mobile mining assets, can be tracked continuously within a Wi-Fi coverage area. The technology operates over any standard 802.11 wireless network and doesn’t require an additional network hardware overlay. ActiveMine recently was approved by West Virginia’s Office of Miners’ Health, Safety, and Training (WV OMHS&T) for use in the state.
In addition, Vital Alert executives say its Through-the-Earth Communications system was the first digital technology to send a very low frequency (VLF) two-way voice signal to depths of 91 meters in a government test mine. Testing was conducted at the U.S. Lake Lynn Experimental Mine operated by the National Institute for Occupational Safety and Health (NIOSH).
The surface-to-ground system connected Sprint Nextel i325 radios located on the surface to the same types of radios in the mine through the Vital Alert system supported by Raytheon JPS Communications’ ACU-1000. The test, conducted over three days, was a collaboration of personnel from Vital Alert, Los Alamos National Laboratory (LANL), Sprint Nextel, and Raytheon JPS. The system will allow users to communicate during critical emergency situations in underground mines and other environments, such as subways, tunnels, and skyscrapers, Los Alamos officials say.
The underground system uses a VLF electromagnetic radiation in the range of 3 to 30 kHz and digital audio compression to transmit wireless voice and data signals through the earth. Other materials that block high RF signals don’t restrict the technology’s signal propagation, according to company officials.
Wireless communications systems are
currently being deployed in some of the largest coal mines in the country.
Separately, Rajant’s BreadCrumb wireless system was approved and listed by the WV OMHS&T for use by mining permit holders.The office validated the tests of the Rajant systems, consisting of an interconnected mesh solution connecting laptops and VoIP phones as far as 975 meters from the mine communications center. The battery-powered wireless access nodes enable voice and data communications across a meshed, self-healing network. They can communicate with other IP-based client-devices such as sensors, video cameras, laptops, and satellite terminals.
For details on how a mine in Colombia is deploying MPT 1327 technology for communications, click here.