Mining Contract: Passive Fiber Optic System for Locating, Tracking, and Communicating with Personnel in Coal Mines

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Contract # 200-2008-24502
Start Date 3/18/2008
End Date 2/28/2009
Research Concept

This contract will develop and demonstrate a modified, fiber optic-based perimeter security system to track personnel in an underground coal mine. The system will use a fiber optic cable strung or buried throughout the mine workings that detects acoustic signals from transmitting beacons worn by miners. A second fiber optic line in the same cable will provide two-way communications using optically powered earplugs at designated breakouts. The tracking sensors and communications equipment will not require electrical power underground. Signal analysis equipment at the surface will allow tracking data to be displayed on a central computer and allow emergency communications between miners and personnel on the surface.

Topic Area

Contract Status & Impact

This contract is complete. To receive a copy of the final report, send a request to

The contractor successfully designed, developed and tested a passive fiber optic system for mining safety. The system was designed to track miners at all times and provide (non-electrical) bi-directional communications in the case of an emergency. With NIOSH personnel, USSI validated the operation of the system at the Pittsburgh Safety Research Coal Mine and the anechoic lab within the Pittsburgh Research Center, Pittsburgh, PA. During this testing, USSI demonstrated the capability of the system to detect miners wearing a USSI beacon under normal mining acoustic conditions. The system distinguished and tracked miners over multiple zones and displayed their locations in a remote building (located up to 1 kilometer away) in real-time. High-fidelity, bi-directional communications were demonstrated between the remote building and a location along the cable 1,200 feet from the surface without the use of electrical power in the mine. Easy installation and retrieval of the system into/from the mine was also demonstrated.


Page last reviewed: July 18, 2016
Page last updated: September 17, 2012