Skip directly to site content Skip directly to page options Skip directly to A-Z link Skip directly to A-Z link Skip directly to A-Z link


Centers for Disease Control and Prevention. CDC twenty four seven. Saving Lives, Protecting People
Search
            ×
                        Mining
                        Mining
                            NIOSH
                            All CDC
                    Submit
                For a full list of topics:A-Z Index
                Advanced Search
            Advanced Search


The National Institute for Occupational Safety and Health (NIOSH)





Mining Contract: Leaky Feeder Mine Communications System
Keywords: Emergencies Leaky feeder communications systems Radios
This page is archived for historical purposes and is no longer being maintained or updated.
Contract #
200-2007-20064Start Date
3/15/2007End Date
12/31/2008Research Concept
The objective of this contract was to investigate techniques to increase the survivability of leaky feeder communication systems. Leaky feeders are two-way radio systems that feature a base station on the surface that communicates with underground radio units, such as walkie-talkie radios. To allow radio frequencies to function underground, a special cable network is installed underground that is designed to "leak" signal. This allows two-way radio transmissions from underground to the surface.Topic Area
Emergency Communications and Tracking
Contract Status & Impact
This contract is complete.
No final report was produced from this contract. For more information on this contract, send a request tomining@cdc.gov.
Under this contract, research and in-mine tests were conducted to investigate techniques for hardening and redundancy to make a leaky feeder mine communications system survivable, as described below.
Hardening - Hardening involves improving the ability of the system cable and components to survive and to continue to perform after mine incidents. Some investigated techniques included cable installation methods, cable stress relief, burying or covering leaky feeder cable, component fire protection, and putting leaky feeder cable in conduit or integrating a messenger.
Redundancy - For redundancy, after a mine incident occurs and communications are lost in the area, a miner can walk a short distance from the affected area and still communicate with the surface. Techniques investigated included a loop-around scheme with multiple base stations located at different surface locations, running independent leaky feeder cables in multiple entries, and using antennas and low-cost cables for coverage extension.The resulting system design uses a Becker Mining Systems ultrahigh frequency (UHF) leaky-feeder communications system, enhanced dramatically to improve its post-accident survivability. The system was installed on a mine-wide basis at the Consol Energy Loveridge Mine for long-term evaluation. It spans an underground distance of 8 miles from the belt slope to the mining sections. Enhancement techniques included the following.
Redundant loops to the surface - With a redundant loop, primary and secondary base stations are connected by overland, fiber-optic links, providing alternate communications paths to achieve redundancy. Two redundant loops, which utilize the belt slope and two airshafts, were used in the Loveridge installation.
Redundant UHF trunks in parallel entries - Since access to the surface is not available beyond the most inby airshaft, redundancy was achieved by installing completely independent UHF leaky-feeder cables in parallel entries, one in the track and another in the belt.
Coverage extension using low-cost cabling and antennas - With the redundant loops, communication coverage was extended to the belt entry by using a low-cost, VHF leaky feeder cable coupled to the main UHF leaky-feeder cable in the track entry. In addition, with redundant UHF trunks in parallel entries, communication coverage was provided in the parallel escapeway by placing antennas in that entry, alternately connecting the antennas to the track and belt leaky-feeder cables. This provides communication in the escapeway if either the track or belt entry leaky-feeder cable becomes non-functional.Successful demonstrations were conducted for industry, labor, and government partners. Various failure modes were injected in the system to simulate mine emergency events. The system performed as designed, providing communication on either side of the simulated fault to the mine surface and between the two underground locations.
See Also
Basic Tutorial on Wireless Communication and Electronic Tracking: Technology Overview
Data Transport Over Leaky Feeder Systems Using Internet-Protocol-Enabled Land Mobile Radios
The Emergency Communication Triangle
How to Operate a Refuge Chamber: A Quick Start Guide
Leaky Feeder to Wireless Media Converter Device Technology Development
Radio 101: Operating Two-Way Radios Every Day and in Emergencies
Technology News 507 - NIOSH Safety Talk: The Emergency Communication Triangle
Theory on the Propagation of UHF Radio Waves in Coal Mine Tunnels
Ultra-Low Frequency Through-the-Earth Communication Technology
Underground Mine Refuge Chamber Expectations Training: Program Development and Evaluation
Page last reviewed: February 24, 2023
Page last updated: February 24, 2023
Content source: National Institute for Occupational Safety and Health, Mining Program
Facebook
        Twitter
        LinkedIn
        Syndicate Mining
        Site BrowserSafety and Health TopicsData & StatisticsMethodologyMine DisastersMSHA Data FilesMine & Mineworker ChartsTools & PublicationsTools You Can UsePublicationsNews & ArticlesResearch ProgramNORA Mining CouncilStrategic PlanMining Program, 2019-2023Miner Health Program, 2020-2030ProjectsContractsFunding OpportunitiesMining LinksAbout UsContact NIOSH MiningEmploymentFacilitiesHistoryVisitor Information Emergency Communications and Tracking
 NIOSH Homepage
 NIOSH A-Z
Workplace Safety & Health Topics
Publications and Products
Programs


About CDC
					Contact Us
					800-232-4636
 Facebook Twitter Instagram LinkedIn Youtube Pinterest Snapchat
 CONTACT CDC
				Contact Us
							Call 800-232-4636
							Email Us
			ABOUT CDC
				About CDC
							Jobs
							Funding
			POLICIES
				Accessibility
							External Links
							Privacy
							Policies
							No Fear Act
							FOIA
							OIG
							Nondiscrimination
							Vulnerability Disclosure Policy
			CONNECT WITH US
				Facebook
								Twitter
								Instagram
								LinkedIn
							Youtube
								Pinterest
								Snapchat
								Email
			LANGUAGES
				Español
							繁體中文
							Tiếng Việt
							한국어
							Tagalog
							Русский
							العربية
							Kreyòl Ayisyen
							Français
							Polski
							Português
							Italiano
							Deutsch
							日本語
							فارسی
							English


U.S. Department of Health & Human Services
			Accessibility
			External Links
			Privacy
			Policies
			No Fear Act
			FOIA
			Nondiscrimination
			OIG
			Vulnerability Disclosure Policy
			USA.gov


Exit Notification / Disclaimer Policy Close
 Links with this icon  indicate that you are leaving the CDC website. The Centers for Disease Control and Prevention (CDC) cannot attest to the accuracy of a non-federal website.
				Linking to a non-federal website does not constitute an endorsement by CDC or any of its employees of the sponsors or the information and products presented on the website.
				You will be subject to the destination website's privacy policy when you follow the link.
				CDC is not responsible for Section 508 compliance (accessibility) on other federal or private website. Website Disclaimers
 Cancel Continue