t t • \ ' o > ^•^q<. 4 ^ » ' ^^-n*. -^o^ "^^ «: *„*'■ <.^.^"-^^:^ ' 'P >i"i ,*' "^^ o* -"^ « • " • ♦ ''b > . " • ♦ '*tt> o"^ r. ' • • . '*'<: . . • ' A A IC 8956 Bureau of Mines Information Circular/ 1983 Health and Safety In-House and Contract Research in Fiscal Year 1984 By Staff, Division of Health and Safety Technology UNITED STATES DEPARTMENT OF THE INTERIOR Information Circular 8956 ii Health and Safety In-House and Contract Research in Fiscal Year 1984 By Staff, Division of Health and Safety Technology UNITED STATES DEPARTMENT OF THE INTERIOR William P. Clark, Secretary BUREAU OF MINES Robert C. Horton, Director Library of Congress Cataloging in Publication Data: ^ / United States, Bureau of Mines, Division of Health and Safety Technology. Health and safety in-house and contract research in fiscal year 1984. (Information circular / U.S. Dept. of the Interior, Bureau of Mines ; 8956) 1. Mine safety— Research— United States. 2, Mine sanitation — Research— United States. I. Title. II. Series: Information circular (United States. Bureau of Mines) ; 8956. -TT^^»§aJ4 622s [622'.8] 83-20013 CONTENTS Page Abstract. 1 Introduction 1 Program outline 2 Part I. — In-house research 2 Health 2 Resplrable dust 2 Control of dust formation 2 Control of generated dust 3 Dust instrumentation and measurement. 4 Radiation hazards 4 Control of radiation hazards 4 Radiation ins trument at ion and measurement 4 Noise control 5 Industrial hygiene (toxic substances) 5 Toxic gases and materials 5 Diesel engine and alternative power sources 6 Ventilation. 6 Safety 6 Fire and explosion prevention 6 Prevention and detection 6 Ignition 7 Suppression 7 Propagation and extinguishment 8 Methane control 8 Fundamental factors 8 Control in advance of mining 8 Control during mining 8 Ground control 9 Mine design and development 9 Hazard detection and monitoring systems 10 Roof support systems 11 Safe support installation 13 Waste stability 13 Industrial-type hazards 14 Electrical 14 Illumination 13 Mine communications and monitoring 15 Human factors 15 Mine equipment safety 16 Haulage and materials handling 16 Postdisaster 17 Survival 17 Communications 17 Rescue and mine recovery 17 Explosives 17 Systems engineering. 18 Systems analysis 18 Test facilities 18 Assistance with program management 19 I^JAHii^ XI CONTENTS — Continued Page Fart II . — Contract research 19 Health 19 Resplrable dust 19 Control of generated dust 19 Industrial hygiene (toxic substances) 19 Diesel engine and alternative power sources 20 Ventilation 20 Safety 20 Postdisaster 20 Rescue and mine recovery • •••• 20 HEALTH AND SAFETY IN-HOUSE AND CONTRACT RESEARCH IN FISCAL YEAR 1984 By Staff, Division of Health and Safety Technology ABSTRACT This publication summarizes the research (in-house and contract projects) programmed by the Bureau of Mines for fiscal year 1984 (October 1, 1983-September 30, 1984) under its Health and Safety Tech- nology Program. The objective of these projects is to provide an ordered and sequenced advance toward the Bureau's overall goal of pro- viding the systems technology required to create a more healthful and safer working environment for the Nation's mining and minerals pro- cessing workers. INTRODUCTION The Bureau of Mines conducts a balanced, continuing in-house re- search and development program to accelerate systematic improvements in health and safety conditions in U.S. mines. Part I of this report outlines the Bureau's present in-house effort to all interested par- ties; in particular, potential contractors can refer to it when sub- mitting USP's (unsolicited proposals), thus avoiding proposing re- search that duplicates work being performed by the Bureau. Part II outlines the Bureau's current projected contract research needs. The projects presented were planned in fiscal year 1983, before Congressional passage of the Bureau's fiscal year 1984 budget. They are, therefore, subject to change based on emerging priorities and availablility of funds. Contingencies may require that a significant portion of the program be deferred into fiscal year 1985 (FY 85) or beyond. Contracts for the Health and Safety Technology Program will be awarded in strict accordance with Federal Procurement Regulations. Availability of requests for proposals (RFP's) will be formally adver- tised in the Commerce Business Daily. No additional information will be supplied on these projects until after the RFP's are made available and then only in strict accordance with prescribed procedures. This document is not intended to solicit proposals from the contracting community. All USP's whose content reflects the objective(s) of the proposed projects listed herein will be returned without formal review. PROGRAM OUTLINE The objective of the Health and Safety Technology Program is to protect the health and safety of mining and min- erals processing workers while insuring that newly developed technology in- corporates health and safety criteria. In achieving this objective, four fun- damental and complementary require- ments must be considered by the research program: 1, Contributing to the viability basic industry. of a The Health and Safety Technology Pro- gram is divided into 12 subprogram areas as shown : Health Respirable Dust Radiation Hazards Noise Control Industrial Hygiene Ventilation Safety 2. Sustaining productivity. 3. Allowing for a return on capital investment. 4. Providing material and energy to the public. Fire and Explosion Prevention Methane Control Ground Control Industrial-Type Hazards Postdisaster Explosives Systems Engineering Since mining and minerals processing involve a highly integrated and inter- related set of functions, the program has been divided into a set of interrelated subprograms, each with goals that will provide systems technology solutions to the problems within the framework of these fundamental requirements. The objectives of these subprograms are described in the following pages, fol- lowed by the planned projects and their corresponding descriptions. The aggre- gate value of the planned in-house proj- ects is approximately $26 million, and that of the anticipated contracts $600,000, PART I, — IN-HOUSE RESEARCH HEALTH Control of Dust Formation Respirable Dust Program Objectives : To investigate basic dust control technologies and con- cepts aimed at preventing the generation and entrainment of respirable dust during the mining cycle. To provide new and improved technology for measuring and controlling airborne respirable dust at levels that meet or are below standards set by the Federal law for all mining and mineral processing operations. Define the Empirical Relationship Between Cutting Parameters, Dust Generation, and Cutting Forces for Coal and Rock Objective ; To conduct basic studies to the relationships between dust generation. determine forces, energy, primary and cutting parameters for coal type, bit geometry and bit usage, and establish a generic mathematical model to optimize any cutting system for minimum dust generation. To continue field tests using the in-seam tester for in situ dust and energy measurements and for verifica- tion of laboratory results. This is a continuation of ongoing efforts, 2. Fundamentals of Dust Formation and Entrainment Objective: To initiate laboratory studies to define the basic parameters and behavior of coal and quartz during coal breakage and how they affect the formation and entrainment of airborne respirable dust. This is a new effort, 3. Study of Coal Dust Wettability Objective : To detemnine the critical performance parameters of surfactants for coal wetting and define the character- istics of a universal surfactant. To investigate the effects of coal surface chemistry on wettability. This is a con- tinuation of an ongoing effort. 4. Mine Inspection Data Analysis System Objective : To conduct a statistical analysis of available dust exposure data and complete the development of the ex- posure index that will aid the Mine Safety and Health Administration (MSHA) in determining its future inspection and sampling strategy. This is a continua- tion of an ongoing effort. Control of Generated Dust 5. Determination of the Extrinsic Parameters Governing the Quartz Exposure of Coal Mine Workers Objective : To complete study of the six cleanest continuous mining sections. Based on the results of the roof bolter dust sources study, to identify improved methods for roof bolter dust control. To evaluate the feasibility and effective- ness of using remote control to reduce the continuous miner operator's dust exposure. To initiate a study to iden- tify dust sources at continuous haulage operations. To explore the concept of using high-pressure atomizing nozzles for control of dust on continuous miner sections. This is a continuation of an ongoing effort, 6. Behavior and Transport of Silica Dust in Room and Pillar Mining Operations Objective : To study the ventilation patterns and airflow characteristics at room and pillar operations and determine their effect on the behavior and trans- port of silica dust. To identify speci- fic areas where silica dust behaves dif- ferently from coal dust and determine how dust control practices need to be modi- fied to compensate for these differences. This is a new effort, 7. Investigation of Quartz Dust Generation During the Removal of Overburden Material at Surface Coal Mines Objective ; To identify and quantify silica dust sources at surface coal oper- ations with special emphasis on sources governing the dust exposure of highwall drill operations. This is a new effort, 8, Identification of Dust Sources and Control Strategies for Auger Extraction of Coal Objective : To determine the dust lev- els at the auger-machine operator — ^jack- setter location, and the effects on dust levels of air turbulence due to water spray and cutterhead motion and changes in airflow patterns. To investigate new and improved water spray and ventilation concepts for more effective dust control. This is a new effort, 9, Identification and Study of the Elemental Sources and Behavior of Respirable Dust as It Relates to Longwall Dust Control Objective : To continue to identify and study the various sources of dust and quantify their impact on the face work- er's dust exposure. To determine the effectiveness of evolving dust control techniques at active longwall faces. This is a continuation of an ongoing effort. 10. Study of Mining Practices and Concepts To Reduce Longwall Dust Objective : To identify work practices and mining cycle modifications to reduce workers' exposure to dust generated dur- ing support movement. To evalute the performance of the most promising tech- niques and provide guidelines to the min- ing industry for implementation of those practices and procedures. This is a con- tinuation of an ongoing effort. analysis of surface coal mine dust sam- ples. This is a continuation of an on- going effort. 14. Rapid and Simple Analytical Technique for Measurement of Asbestos in Dust Samples Objectives : To investigate the techni- cal feasibility of using electrophoresis as a means to analyze dust samples for asbestos fibers. This is a new effort. 11. Define and Characterize Sources of Mill Dust and Its Control Objective ; To conduct studies to de- fine mill dust sources using a tracer gas technique and identify appropriate con- trol measures. To determine the level of dust generated during dumping and crush- ing operations and investigate the most effective suppression techniques. This is a continuation of an ongoing effort. Dust Instrumentation and Measurement 12. Study of Respirable Dust Monitoring Strategies and Evaluation of Dust Measurement Concepts Objective : To complete the study of the tapered-element oscillating micro- balance (TEOM) dust sensing technology to determine sensitivity, accuracy, pre- cision, and other performance and relia- bility factors. To evaluate the perform- ance of the MINIRAM and the continuous respirable dust monitoring system. To continue development of a monitoring strategy for controlling respirable coal mine dust. This is a continuation of an ongoing effort. 13. Detennination of Silica Particle Size Distribution in Respirable Mine Dust Samples Objective : To determine the size dis- tribution of mineral particulates col- lected from underground coal mines by scanning electron microscope (SEM) image analysis with special emphasis on size of silica particulates as related to the various coal seams. To initiate similar Radiation Hazards Program Objective : To advance the state of measurement and control technol- ogy for protection of miners from expo- sure to radon and radon daughters and other nuclear radiation hazards in ura- nium and other mines. Control of Radiation Hazards 1. Radon Control Technology Objective: To complete studies to determine the effectiveness of activated charcoal filters in reducing radon con- centrations. To define and investigate the parameters that influence the release of radon from radivim-bearing ores , and develop a computer code to model the release of radon into the mine atmosphere considering ventilation pressures , mining activities, and inactive mines. This is a continuation of an ongoing effort. Radiation Instrumentation and Measurement 2. Personal Exposure Measurement Objective : To investigate the sensi- tivity and response of passive alpha detectors for radon measurements and study methods for measuring long-lived alpha emitters. To determine physical characteristics of radon daughters in mine atmospheres. To continue to evalu- ate the accuracy and reliability of emerging radiation measurement technol- ogy. This is a continuation of an on- going effort. Noise Control Program Objectives: To work with In- dustry to Identify noise sources in underground and surface mines and in related mineral cleaning and preparation facilities, and to abate these noise sources sufficiently to meet Federal noise exposure standards. 1. Hearing Protector Research Objective; To determine backgrbund noise levels under earmuffs and to study errors in the two-microphone attenuation measurement method. This is a continua- tion of an ongoing effort. and certain particulates produced by explosives, combustible materials, and diesel engines. To develop and evaluate new instrumentation for monitoring these substances. To develop and/or refine analytical techniques for measuring and characterizing toxic substances, and in- vestigate methods for controlling the formation and accumulation of toxic prod- ucts. To analyze alternative power sources that may have health advantages over existing mine diesels. Toxic Gases and Materials 1. Toxic Fumes From Explosives and Other Materials Used in Mining 2. Noise Abatement Profile Objective; To implement a computerized noise abatement profile and data base for the mining industry. This is a new project. 3. Mining Equipment Noise Control Objective: To investigate new techni- cal approaches to quieting load-haul-dump machines, continuous miner cutting heads, jumbo-mounted drills, and handheld hard rock drills. This is a continuation of an ongoing effort. Objective : and quantity vapors , and detonation of thermal oxidat bustion of mat mining operat effect of low ginal primary or to imprope production of ing. This is going effort. To determine the identity of fixed gases, chemical residues produced by the explosives and by the ive degradation and com- erials used in underground ions. To determine the order reaction due to mar- , deteriorated explosives, r delay intervals in the toxic fumes during blast- a continuation of an on- 2. Monitoring and Measurement of Contaminant Gases 4. Basic Technologies for Mining Noise Control Objectives; To investigate the noise- generating machanisms of percussion drills and chain conveyors and to study the effectiveness of various noise con- trols. To research engineering designs aimed at reducing longwall shearer noise levels. To investigate the effect of the mining environment on the acoustical properties of materials. This is a new project. Industrial Hygiene (Toxic Substances) Program Objectives; To identify and control health hazards in surface and underground mines and mineral processing plants caused by toxic gases and fumes, Objective; To devise and evaluate methods and devices that can be used effectively and efficiently by the mining industry to evaluate, maintain, and im- prove the working environment in under- ground mines. This is a continuation of an ongoing effort, 3. Cyanide Hazard in Cleaning "State of Maine" Filters Objective; To devise simple and reli- able cleaning procedures for "State of Maine" filters, used in the mining in- dustry to collect the gold and silver in pregnant cyanide leach solutions, that minimize employee exposure to cyanide and cyanide compounds produced during clean- ing. This is a new project. 4. Measurement and Control of Welding Fumes 2. Improved Stopping, Door, and Overcast Construction for Oil Shale Mines Objective: To assess related industry practices pertaining to measurement and control of welding and cutting fumes, dust, and radiation, and adapt this tech- nology to confined work areas found in the mining environment. To determine the quantity and character of welding pol- lutants and personnel exposure levels. To propose control systems and/or isola- tion techniques to reduce or eliminate exposure to toxic substances resulting from welding and cutting. This is a con- tinuation of an ongoing effort. Objectives; To establish the essential characteristics of stoppings subject to blast damage, high differential pres- sures, and roof, rib, and floor movement. To establish the required characteristics of stoppings, doors, and overcasts em- ployed in large-opening mines , and use these characteristics to create concep- tual designs. This is a new project, SAFETY Fire and Explosion Prevention 5. Diesel Engine and Alternative Power Sources Research To Control Diesel Engine Particulate Emissions Objective; To investigate the reduc- tion of miner exposure to diesel exhaust through identification, development, and evaluation of exhaust control technology such as fuel additives and filters. This is a new project. Ventilation Program Objectives; To develop venti- lation systems required to maintain a safe and healthful atmosphere conducive to efficient work output in noncoal mines, 1 , Improving Ventilation in Noncoal Mines and Mills Program Objectives ; To reduce the potential for a fire or explosion in min- eral extraction and processing opera- tions , to minimize the danger to people on account of fires or explosions that do occur, and to diminish the vulnerability to such attendant hazards as high temper- ature, asphyxiating and toxic fumes, and explosive gas mixtures. Prevention and Detection 1, Investigation of Fundamental Approaches to Fire Warning in Underground Mines Including Stench Gas, CO Indicators, and Human Response Objective ; To continue an ongoing effort to reduce fire warning time for deep underground metal mines and ensure appropriate response by miners to warning signals. Objectives ; To investigate the aero- dynamics of face ventilation systems in large opening mines, to apply the thermo- dynamic principles of air-to-water heat exchange to the cooling of hot mines , and to investigate improved mine stopping construction techniques, especially in large-opening mines. This is a continua- tion of an ongoing effort. 2, Hazard Detection and Instrumentation Objective ; To continue an ongoing effort to identify, evaluate, and improve upon promising fire sensors and fire- sensing systems for use in underground mines. To develop prototype systems capable of (1) remote measurement of methane and other flammable gases and (2) low-level smoke sensing, 3. Implementation of Coal Dust-Rock Dust Regulations Objective ; To continue an ongoing effort to provide improved instrumenta- tion to enable MSHA to more readily determine compliance with current rock dust regulations. To validate the ef- fectiveness of techniques such as water spray systems to reduce float coal dust. To maintain awareness of non-rock-dust alternatives for explosion prevention, 4. Fires in Mine Passageways Objective ; To continue an ongoing effort to provide data on mine fire parameters, such as fire growth rate, ignition source intensity, and fire size, that can lead to improved and realistic fire detection and a more realistic plan- ning of fire emergency procedures. 5. Characterizing the Effect of the Mining Environment on Underground Metal Mine Fire Detection Objective ; To continue an ongoing effort to perform highly complex analyses of fire growth and containment spread using real-time inputs from in-mine detection instruments. Ignition 6. Ignitability of Mineral Dusts, Gases, and Vapors Objective ; To continue an ongoing effort to develop and promulgate new and more reliable explosivity and ignitabil- ity indices for use in classifying dusts according to their hazard potential. Continue thermal and spark-ignitability studies in a new and larger furnace to permit more accurate control over the environments simulated as a representa- tion of those encountered in mines. 7. Fire Hazards of Mine Combustibles Objectives rates of mine materials under sloping conditions. 8, Pacification of Sulfide Oxidation Objective ; To continue an ongoing effort to determine the kinetics and mechanisms of low-temperature oxidation of sulfides, particularly pyrite; to identify the rate-controlling step(s). To apply the result of this study to identify chemical and physical inhibitors and validate, first in large-scale labor- atory tests and ultimately in mines, the ability of these inhibitors to prevent or retard sulfide oxidation and thereby re- duce the probability of mine fires and resultant loss of property and life. 9. Spontaneous Combustion Research Objective ; To continue an ongoing effort to study the self -heating of mate- rials under realistic conditions in order to provide criteria for prediction and prevention of spontaneous combustion occurrences. Suppression 10. Laboratory Dust Flammability Studies Objective ; To continue an ongoing effort to delineate the domain of flamma- bility for mixtures of coal dust-rock dust-methane in air. To find new, cost- effective supplements or substitutes for rock dust, and to continue testing, cali- bration, and improvement of a laboratory- scale explosivity test apparatus, 11, Microscopic Structure and Composition of Combustible Dusts and Residues Objective ; To continue an ongoing effort to conduct quantitative micro- scopic structure studies, size distri- butions, and composition analyses of various dusts with the SEM, electron microscope, and to apply the data obtained to combustion research and the forensic science of postdisaster investigation. To continue an on- going effort to evaluate flame spread 12. Propagation and Extinguishment Fire and Explosion Hazards of Oil Shale Mining and Oil Mining factors influencing the occurrence of methane to the development of techniques to control methane in advance of and dur- ing mining. Objective ; To continue an ongoing effort to provide guidelines for fire and explosion prevention during all phases of oil shale mining and processing. 13. Full-Scale Mine Explosion Research Objective ; To continue an ongoing effort on the ignition propagation and suppression of full-scale explosions of coal dust, oil shale dust, and gas in the Bruceton and Lake Lynn Experimental Mines; and to improve and maintain the instrumentation in both facilities. 14. Prevention and Suppression of Ignitions and Explosions Objective ; To continue an ongoing effort to develop, test, and conduct field trials of (1) new tool bit materi- als and/or tool bit geometries for the prevention of face ignitions, (2) bar- riers for the suppression of gas and coal dust explosions, and (3) sintered metal- lic components in braking systems of underground coal mine equipment to deter- mine the extent of the friction hazard. 15. Mine Fire Diagnostics and Extinguishment Objective ; To continue an ongoing effort to develop needed guidelines for safe reopening of a mine following seal- ing of a coal mine fire, to evaluate mine fire detection and suppression systems, and to evaluate full-scale fires involv- ing other mine combustibles such as mine dusts, brattice curtains, and conveyor belts. Methane Control Program Objective ; To develop the technology that will enhance the ability of the mining industry to more effec- tively control methane in underground coal mines. The technology involved ranges from determining the fundamental Fundamental Factors 1. Fundamental Factors Affecting Methane in Coal and Associated Strata Objective ; To determine the influences of geology on the occurrence and emission of methane. This is a new project. 2. Understanding the Mechanisms of Gas Outbursts in Coal Objective ; To assess the potential for and the minimizing of gas outburst haz- ards in coal mines. This is a new project, 3. The Geology of Methane in Metal and Nonmetal Mines Objective ; To determine the influence of geology on the occurrence and emission of methane in metal and nonmetal mines. This is a new project. Control in Advance of Mining 4. Vertical Borehole Methane Drainage Longwall Mine Safety Objective ; To evaluate improved tech- niques of vertical borehole drainage for longwalls. This is a new project. Control During Mining 5. Protection of Methane Drainage Systems Objective ; To investigate improved techniques for protecting methane drain- age systems. This is a new project. 6. Methane Drainage for Low Permeability Coalbeds Objective: To influence horizontal drilling and completion technology for use in low-permeability coalbeds. This is a new project. 7. Longwall Gob Gas Control Using Cross Measure Boreholes Objective ; To evaluate new techniques for gob degasification. This is a new project, 8. Development of Methane Control Strategies in Metal and Nonmetal Mines Objective ; To develop and evaluate specific methane control strategies for metal and nonmetal mines. This is a new project. 9. Ventilation for Methane Control steep coal seams and multiple seams. This is a continuation of an ongoing effort. 3. Field Investigation of Coal Mine Pillar Design Objective : To identify major problems related to current designs of chain pil- lars and barrier pillars , and validate the design concepts using field instru- mentation data and regressive integrity factor analysis. This is a continuation of an ongoing effort, 4. Geophysical Validation of Coal Mine Pillar Integrity Objective ; To conduct research on im- proved ventilation techniques for methane control in coal mines. This is a contin- uation of an ongoing effort. Ground Control Program Objectives ; To develop tech- nology that can be applied by the mining industry to reduce accidents due to the failure of underground mine roof, face, and ribs, and the collapse of surface mine and waste embankment slopes. Mine Design and Development 1. Delineation of Abandoned Mine Workings and Other Mining Hazards With Integrated Geophysics Objective ; To field-test seismic, radar, controlled-source audio magneto- telluric, and resistivity techniques, determine relationships of various geo- physical methods, and determine most appropriate methods for identification of mine hazards through multiple data set analysis. This is a continuation of an ongoing effort. 2. Structural Analysis and Design for Longwall Mining Objective ; To apply numerical modeling techniques to identify optimum entry con- figurations, pillar designs, and single- entry development for longwall mining of Objective ; To evaluate geophysical methods for determination of the extent of and characteristics of yielded zones in coal mine pillars. This is a new project, 5, Evaluate Borehole Instruments for Rock Mechanics Investigations Objective ; To complete field and lab- oratory evaluation of the borehole shear tester and the improved borehole pressure cell, and initiate laboratory testing of a two-component physical property gage and a soft borehole deformation gage. This is a continuation of an ongoing effort. 6, Roof and Pillar Stability at Coal Mine Intersections Objective ; To analyze stresses and deformations in the roof and ribs at entry intersections of coal mines using numerical modeling techniques, and verify the results with field measurement of convergence and stresses. This is a new project, 7, Stress Technology for Improved Mine Design Objective ; To evaluate the effect of in situ stress fields on ground control problems and the potential of stress technology in improving mine structural design. This is a new project. 10 8. Geologic Studies for Coal Mine Ground Control Objective ; To classify hazardous geo- logic features of coal mine roof and identify suitable roof support tech- niques. This is a continuation of an ongoing effort, 9. Ground Control Design Procedures for Multiple-Seam Coal Mining Objective ; To assess the impacts of a previously mined coal seam on ground con- trol in active mine workings and develop design criteria for multiple-seam coal mining. This is a continuation of an on- going effort. 10. Health and Safety Recommendations for Single-Entry Longwall Mining Objective ; To determine recommended variances in health and safety require- ments for single-entry development sys- tems for retreat longwall mining. This is a continuation of an ongoing effort. 11. Model Studies and Field Verification of Roof Bolting Criteria Objective ; To develop design guide- lines for mine roof reinforcement using various types of roof bolts by collating the results of full-scale model testing, finite-element computer analysis, and in- mine tests. This is a continuation of an ongoing effort. 12. Engineering Data Base for Coal Mine Ground Control Planning Objective ; To develop and establish a centralized geological and engineering data base for coal mine control planning and design. This is a new project. 13. Blasting Parameters That Affect Highwall Stability Objective ; To complete field evalua- tion of improved blasting practices for highwall stability in surface coal mines. This is a continuation of an ongoing effort. 14. Application of Geodynamic Accumulated Strain Sensor to In Situ Rock Stresses Measurement Objective ; To develop acoustic trans- ducers for in situ rock stress measure- ment based on pulsed-phase-locked-loop technology and demonstrate their applica- tion. This is a continuation of an on- going project. 15. Evaluation of Ground Stability Problems in Quarry Operations Objective ; To identify ground control hazards in deep slate quarries, and dem- onstrate application of geotechnical engineering to quarry planning and opera- tions for highwall safety. This is a continuation of an ongoing effort. 16. Mine Void Mapping With Controlled-Source Audio Magnetotelluric System Objective ; To evaluate the use of a controlled-source audio magnetotelluric system previously developed under Bureau contract for mapping mine voids and ge- ologic anomalies. This is a continuation of an ongoing effort. 17. Roof Stability Through Automated In-Mine Environmental Control Objective ; To complete the laboratory study on time-dependent behavior of coal measure rocks due to moisture effects. This is a continuation of an ongoing effort. Hazard Detection and Monitoring Systems 18. Automated Microseismic Roof Fall Warning System Objective: To complete verification of the capability of high-frequency, micro- seismic single-point transducer systems in predicting and warning against small roof falls, and transfer the innovative technology to the industry. This is a continuation of an ongoing effort. 11 19. Coal Mine Bounce and Outburst Studies Objective : To assess the reliability of low-frequency mlcroselsmlc monitoring techniques to delineate areas of eventual coal bounce failure, and high-frequency techniques as a warning system for out- bursts. This Is a continuation of an ongoing effort. 24. Acoustic Cross-Borehole and In-Mine Roof Hazard Detection Systems Objective ; To complete assembly of the low-frequency, acoustic cross-borehole hazard detection system. Install the Instrumentation In a field logging ve- hicle, and conduct performance tests. This Is a continuation of an ongoing effort. 20. Three-Dlmenslonal Remote-Sensing Data Analysis for Mine Hazard Prediction Objective ; To Investigate a com- posite methodology to construct three- dimensional mine hazard maps by combining satellite Imagery data, aerial photo- graphs, geologic and geophysical Informa- tion, and digital terrain mapping. This Is a continuation of an ongoing effort. 25. Prediction and Control of Rock Bursts and Failures In Mines Objective : To complete Improvements of the standard mlcroselsmlc rock burst mon- itoring system and analysis procedures, and continue collection of mlcroselsmlc and electromagnetic radiation data at the Galena Mine for Improving failure predic- tion capability. This Is a continuation of an ongoing effort. 21. In-Seam Hazard Detection Using Geophysical Techniques 26. Detection of Imminent Rock Failure In Deep-Vein Mines Objective ; To evaluate high-resolution guided wave seismic and radar technol- ogies that are reliable and accurate In detecting and locating hazardous geologic features and mine voids within a coal seam. This Is a continuation of an on- going effort. 22. Mine Inundation Warning Systems Objective ; To complete field evalua- tion of practical methods and instruments for inundation warning in underground coal mines. This is a continuation of an ongoing effort. Objective ; To complete field evalua- tion of the improved seismic rock burst monitoring system using fiber optic links for data transmission. This is a contin- uation of an ongoing effort. Roof Support Systems 27. Arch Canopy Research Objective ; To determine the dynamic response of arch canopies, their struc- tural components, and tunnel liner back- fill systems to Impact loading. This is a continuation of an ongoing effort. 23. Critical Parameters Controlling Roof Stability Objective ; To investigate roof-to- floor closure rate criteria for roof fall prediction using potentlometric and ultrasonic closure rate devices. This is a continuation of an ongoing effort. 28. Fundamental Drill and Bolt Parameters Affecting Roof Integrity Objective ; To determine if roof bolts can be installed with uniform tension in widely varying roof conditions and deter- mine roof stability that results. This Is a continuation of an ongoing effort. 12 29. Ground Control System Safety Analysis Objective : To examine ground control accident reports to determine trends and significance of conditions and circum- stances contributing to accidents and fatalities. This Is a continuation of an ongoing effort. 30. Inorganic Cementing Materials Objective : To develop chemical binders and methods of application to mine roofs to Increase the mine roof stability, with special attention to potential Inorganic binders. This Is a continuation of an ongoing effort. 31. Investigation of Factors Associated With Cutter (Shear) Roof Objective : To perform engineering and geologic studies to determine causes of cutter roof. This Is a continuation of an ongoing effort, 32. Support of Thick Coal Roofs In Western Mines Objective : To determine optimum sup- port devices for safe, effective support of underground mine roofs composed of thick, top coal. This Is a continuation of an ongoing effort. 33. Support for Large Underground Openings Objective : To formulate, develop, and test concepts for ground support systems to stabilize large underground openings In thick-seam coal. This Is a continua- tion of an ongoing effort. 34. Passive Roof Supports To Control Ground Objective : To develop fundamental data on the function of passive, artificial yielding roof supports used during min- ing. This Is a continuation of an on- going effort. 35. Corrosion of Metallic Roof Support Elements Objective : To develop guidelines to aid MSHA and mining personnel In predict- ing the life of roof support systems , determine detrimental effects of cor- rosive mine environments on friction rock stabilizers (split set), and help Identify potential control measures. This Is a continuation of an ongoing effort. 36. Nontensloned Rock Reinforcement Objective ; To develop nontensloned, full-column Inorganic grouted rock bolts for use In metal and nonmetal mines; com- plete testing of a scaler for use In metal and nonmetal mines. This Is a con- tinuation of an ongoing effort. 37. Minimum Column Lengths for Resin-Grouted Bolts In Evaporltes Objective : To determine the minimum column lengths required to Insure safe working conditions when rock conditions are such that some grout Is forced out Into the rock mass. This Is a continua- tion of an ongoing effort. 38. Flexible Dlstrlbuted-Load Support System Objective ; To define the Interactive mechanics of flexible dlstrlbuted-load supports; to determine the critical pa- rameters that control the backpacking materials; to alternative materials (other for use as flexible liners; how a flexible support system could be Integrated Into the excavation cycles In highly stressed or broken ground; and to establish and verify a theory for flex- ible dlstrlbuted-load support that will lead to effective design and Implementa- tion of the systems. This Is a new project. selection of Investigate than steel) to determine 13 39. Roof Bolt Effectiveness Monitoring Using High-Frequency Microseismic System Objective: To evaluate data analysis techniques of self-generated rock noise (ultrasonic frequency range) as related to dynamic structural response in under- ground mines. This is a new project. 40. Push-Out Pillar Support System for Retreat Mining Objective ; To design and evaluate push-out pillars and the immediate sup- port systems required to maintain a safe working area in a room and pillar retreat section. This is a new project. 41. Safe Support Installation Support-Rock Interaction Mechanics for Full-Column Bolting trusses. This is a continuation of an ongoing project. 44. Effects of Bolt Installation Procedure on Mine Roof Stability Objective : To determine bolting proce- enhance or degrade roof sta- is a continuation of an dures that bility. This ongoing project. 45. Longwall Mining Investigations Objective : To develop data on support loadings and strata activity associated with the development of longwall gateroad entries and subsequent mining of longwall panels; to evaluate techniques for strata stabilization and void fillings. This is a continuation of an ongoing project. 46. Systems Interaction for Support Installation Objective : To develop fundamental knowledge and understanding of the be- havior of full-column bolting in under- ground mines, especially using non- standard grouts and bolts. This is a continuation of an ongoing project. 42. Research on the Initiation, Monitoring, and Destressing of Coal Mine Bounces, Coal Bursts, and Gas Outbursts in Deep Western Mines Objective ; To integrate field measure- ments and observations with numerical analysis and laboratory studies to gain a better fundamental understanding of why a bounce, burst, or outburst occurs and how to eliminate or reduce them in coal mine entries and longwall faces. This is a new project. 43. Theory and Mechanics of Roof Truss Behavior Objective : To develop basic data on the support characteristics of roof trusses, to determine the performance of a field roof truss tension measuring device, and to evaluate concepts to pro- vide faster and safer installation of Objective : To evaluate support in- stallation concepts that remove the miner from immediate danger when placing bolts. This is a continuation of an ongoing project. 47. Retreat Mining Geomechanics Objective : To determine the mechanisms of roof collapse during retreat mining and establish guidelines to improve the safety of retreat mining. This is a con- tinuation of an ongoing effort. 48. Relation of Dynamic Roof Bolt Loads to Mine Stability Objective : To determine factors influ- encing roof bolt load and relate their influence to mine stability. This is a new project. 49. Waste Stability Generic Modeling of Waste Embankments and Backfilled Structures Objective : To design and validate generic models via mathematical analysis. 14 computer codes, and centrifuge testing for the evaluation of the design and con- struction of surface waste embankments and underground backfilled mines. This is a new project, 50, Surface Disposal of Mine Waste and Mill Tailings Objective : To investigate methods of slurried waste deposition that will place higher strength materials close to the embankment, and concepts for the disposal of fine coal refuse that eliminate the need for slurry impoundments. This is a new project. Electrical 1, Intrinsic Safety Objective ; To investigate problems related to the basic understanding of intrinsic safety, supply technical sup- port to Bureau of Mines researchers , con- tractors, and MSHA, and participate in national and international committees to develop recommendations for using elec- trical equipment in potentially explosive atmospheres. This is a continuation of an ongoing effort. 2. Permissible Equipment 51, Consolidation of Coal-Clay Waste by an Improved Flocculation Technique Objective : Demonstrate the feasibility of using an improved flocculation tech- nique to dewater fine coal waste sludge to produce a consolidated, stable waste material. This method will be field tested using polyethylene oxide as a flocculating agent. This is a continu- ation of an ongoing effort, 52, Evaluation of Filter Cloth for Stabilizing Coal Mine Waste Objective : To improve the stability of coal mine refuse piles through a deter- mination of the long-term effectiveness of using synthetic filter cloths to assist in embankment drainage. This is a continuation of an ongoing effort. Objective : To develop a design guide and quality assurance standards for explosion-proof enclosures, begin testing a medium-high (600 to 8,000-V) voltage connector, and develop acceptance and test criteria for high-voltage permis- sible load centers. This is a continua- tion of an ongoing effort, 3, Grounding and Ground Fault Protection Objective ; To modify existing sensi- tive ground fault interruptors or develop new units for use in U,S, underground mines, and to test those units for dura- bility and shock prevention and establish applicable standards for future use. This is a new project, 4, Mine Power System Safety and Reliability Industrial-Type Hazards Program Objectives : To (1) determine how the quality of training can be in- creased to insure miners can do their tasks safely and productively, (2) define the role of the human in all aspects of tasks required during the mining cycle, (3) determine how the human can be pro- tected from the hazards of mining, (4) determine what information must be avail- able to the miner and at what level to increase safety, and (5) determine what information must be available to reflect the human requirements in equipment designed for mining. Objective : To investigate mine power system problems that have the potential for causing mine fires, methane explo- sions, and exposure of mine personnel to electrical hazards, and to develop tech- nology to improve the reliability and maintainability of power systems. This is a new project, 5, Inherently Safe Electrode Reactions for Use in Electrokinetic Dewatering Objective : To investigate cathode reactions that will be inherently safe and can substitute for the hydrogen- generating reduction of water in the 15 electrokinetic process of dewatering mine tailings. This is a new project. Illumination 6. Investigation of Minimal Luminance Requirements for the Mining Industry Objective ; To collect and analyze data from surface and underground mines that can be used to evaluate and recommend minimal luminance levels for the in- dustry. This is a new project. 7. Fundamental Research on Potential Use of Large Diameter Fiber Optics for Area Illumination Objective : To evaluate the potential use of fiber optic illumination systems in underground mines with emphasis on glare reduction, safety, reliability, maintenance, and economics. This is a new project. Mine Communications and Monitoring 8. Mine Telemetry and Environmental Surveillance Systems Objective : To collect basic in-mine data on environmental mine monitoring systems. The data will be used for eval- uation of system reliability, sensor and transducer performance, and data secur- ity. This is a continuation of an on- going effort. 9. Performance Standards and Systems Approach to Mine Monitoring Objective : To develop and evaluate criteria for an intrinsically safe mine monitoring system. The research will concentrate on a systems approach, relia- bility, sensors, and data security. The system provides adequate safety protec- tion that is cost effective. This is a continuation of an ongoing effort. 10. Electromagnetic Signal Propagation in Underground Mines Objective : To evaluate techniques to improve the range and reliability of medium-frequency (MF) radio propagation along with an investigation of MF appli- cation to in-mine data transmission. This is a continuation of an ongoing effort. Human Factors 11. The Investigation of Improved Management Practices for the Mining Industry Objective : To ascertain the relation- ship of current management practices to miners' safety, productivity, and turn- over rates; and on the basis of the find- ings from this work, recommend approaches for the improved management of coal min- ers. This is a new project, 12. Human Factors of Manual Materials Handling in the Coal Mining Industry Objective : To identify and define the hazards of manual materials handling in the coal mining industry, and to develop manual materials handling guidelines spe- cific to the needs of the coal mining industry. This is a new project. 13. Computer Modeling of Mining Crew Stations Objective ; To determine the demands placed on mobile equipment operators while operating underground coal mining machinery and to incorporate the results into the ongoing work on developing a computer model of operator compartments. This is a continuation of an ongoing effort, 14. Reduction of Human Error Accidents in Underground Mining Objective : To reduce mining accidents and injuries associated with "human error," and to improve productivity re- lated to human performance. This is a continuation of an ongoing effort, 15. Research To Enhance the Conduct of New Hire, Refresher, and New Task Training Objective ; To enhance the effi- ciency and effectiveness of mine training 16 through the systematic investigation, study, and development of performance criteria and competency-based training methods. This is a continuation of an ongoing effort. 16. Fundamental Factors of Operator Alertness To Enhance Surface Mining Safety Objective : To determine human be- havioral aspects of the man-machine- workplace interface that contribute to unsafe behavior in surface mining, de- velop practical techniques that can cor- rect these problems, and test such tech- niques under controlled conditions that simulate the mining environment. This is a new project, 17, Blasters Training for Metal-Nonmetal Miners Objective : To prepare recommendations the development of materials that be used for classroom and on- f or would the-job training of blasters in metal and nonmetal mines. This is a new project. Mine Equipment Safety 18. Application of Robotics to Underground Mining Objective ; To conduct an intensive, systematic study directed toward greater knowledge and understanding of robotics to determine the potential for the devel- opment of mining systems that will rely primarily on robotics technology to in- crease safety. This is a continuation of an ongoing effort, 19, Equipment Technology for Reduced Accidents Objective ; To explore the application of innovative technology to improve health, safety, and productivity in min- ing. Areas addressed by the program are ground fall protection for operators of thin-seam face equipment, braking systems on mobile face equipment, worker injury related to slipping, and accidents analy- sis. The scope of mining areas included in the program is intentionally broad. covering specific problem areas that lend themselves to long-term engineering solu- tions. This is a continuation of an ongoing effort. 20. The Fundamentals of Electromechani- cal Technology for Large Mobile Mine Equipment Automation Objective : To improve safety of the mobile mine equipment operator's work environment ; delineate the fundamental aspects and improve the associated tech- nology to make mobile equipment operators more aware of their surroundings ; and delineate automation priorities on large mobile mining equipment. This is a con- tinuation of an ongoing effort. Haulage and Materials Handling 21. Evaluation of Conveyor Belt Cleaners Objective ; To reduce belt cleanup requirements, through research to deter- mine the parameters to increase the effectiveness of conveyor belt cleaners, and thus reduce the exposure of mine maintenance personnel to the dangerous cleanup job. This is a continuation of an ongoing effort. 22. Hoisting Systems Research Objective ; To increase the safety and efficiency of hoisting operations by (1) quantifying the effects of degradation upon the structural integrity of hoist rope and (2) studying the relationship between material deformation and energy dissipation for utilization in hoist arrestments. This is a continuation of an ongoing effort, 23. Haulage and Materials Handling Accident Reduction Objective ; To isolate the causes of powered haulage and materials handling accidents and to develop concepts and guidelines for equipment design that will reduce the injuries resulting from these operations in underground coal mines. This is a continuation of an ongoing effort. 17 24. Wire Rope Inspection, Retirement , Selection, and Use Objective ; To investigate present methods and, where appropriate, derive better methods for inspection, use, and selection and for combining underground mine hoist-rope and associated equipment, and to prepare new hoist-rope retirement (replacement) criteria. Existing inade- quate retirement criteria will be re- placed by Improved criteria that will Increase the reliability and safety of man and/or material hoisting operations. This is a continuation of an ongoing effort. 25. Laboratory Analysis of Wire Rope Objective : To define and control the microstructure of wrought, pearlltlc steel, wire, hoist ropes to extend fa- tigue life, and to perform metallurgical analyses such as chemical composition and microstructure determinations to support the needs of the entire Wire Rope Program at the Bureau of Mines Pittsburgh, Spo- kane, and Albany Research Centers, This is a continuation of an ongoing effort, Postdisaster Program Objectives : To develop the technology that will enhance the chances of miners to escape, survive, and/or be rescued following mine fire, explosion, or outbursts of gas. This involves per- sonal protection equipment for miners and rescue teams, preplanned rescue and sur- vival systems, and devices to detect, locate, and communicate with trapped miners. Survival 1. Life Support for Escape and Rescue Objective ; To conduct research to investigate the physiology of escape and rescue and the use of metabolic breath- ing simulators in testing and design of breathing apparatus, and to enable long-term field evaluations of self- contained self -rescuers. This is a new project. Communications 2. Evaluation of the Concept of a Medium-Frequency Radio System for Mine Rescue Objective : To evaluate medium- frequency radio system for its applica- tion to mine rescue operations and com- munication with trapped miners. This is a new project. Rescue and Mine Recovery 3. Gas Instrumentation for Rescue Teams Objective : To quantify the effects of selected atmospheric and environmental parameters in commercially available methane detection instruments. This effort is in direct response to an MSHA request. This is a new project. 4. Evaluation of a Deep Mine Rescue System Objective : To evaluate a deep-mine electromagnetic rescue system. This is a continuation of an ongoing effort. Explosives Program Objectives : To maintain sur- veillance over permissible explosives and related items; determine hazard charac- teristics of explosive substances, de- vices, and systems not classified as per- missible; and conduct research to support MSHA in establishing and enforcing mean- ingful standards and in investigating accidents related to explosives. To con- duct fundamental studies of explosive behavior and apply results to new tech- nology. To develop new and improved test procedures as new mining methods are Introduced and new types of explosives are formulated. 1, Development of Safer Blasting Procedures and Improved Explosive Hazard Techniques Objective ; To continue an ongoing effort that increases safety in blasting techniques and reduces explosive hazards 18 in underground coal mines by (1) deter- mining how blasting parameters affect the probability of ignition in multiple-delay blasting, (2) defining and evaluating sheathed explosives for specific applica- tions and then proposing scheduled tests for their approval, and (3) providing hazard criteria and test procedures for new explosives, blasting agents, initi- ating systems, and related devices in- volved in accidents. 2. Effect of Explosive Properties and Blasting Procedures on Incendivity and Performance Objective ; To continue an ongoing effort to evaluate new candidate per- missibles and insure that certified per- missibles are made to specifications. To study conditions that will improve safety and performance, including those of the relatively new water gel and water emul- sion permissibles. To improve blasting procedures in gassy noncoal mines by identifying hazards of stemming in large bias tholes and improving blast area security technology. 3. Basic Understanding of Deflagation and Detonation Phenomena Systems Analysis 1. Effectiveness of Mine Systems Objective ; To continue an ongoing effort to determine cost effectiveness of Bureau safety systems and hardware in order to accelerate their adoption by the mining industry; and to perform mine haz- ard analyses of total mine operations and address interactions among health and safety problems that occur. To update data on mine equipment use for identify- ing potential hazards in coal mining operations; and to acquire data that in- corporate multidisciplined, basic re- search on solutions to deal with emergen- cies, prevent or mitigate disasters, and reduce accidents. 2. Analysis of Mine Systems Objective ; To continue an ongoing effort to provide the mining industry with the most modern safety management techniques at a minimum cost to the mines. Test Facilities 3. Operation of the Lake Lynn Laboratory Objective ; To continue an ongoing effort to understand conditions that cause explosives to malfunction by in- vestigating fundamental physical thermo- dynamic hydrodynamic parameters. Systems Engineering Program Objectives ; To develop methods for evaluating the impact of specific technological improvements or inade- quacies on the total mining operations and identify problems whose solutions would provide the greatest health and safety benefit. To operate and maintain underground research and test facilities for use in testing and demonstrating new procedures and equipment before they are tested in commercial mines. Objective: To continue an ongoing effort to operate and maintain special- ized full-scale underground and surface test facilities. Examples of research activities to be pursued include (1) re- evaluation of passive barrier deployment guidelines, (2) test of triggered barrier systems mounted on a continuous miner, (3) validation of concepts on the igni- tion and propagation of coal dust explo- sions, (4) evaluation of large-scale burn tests involving explosives and blasting agents, and (5) acquisition of data for approval of sheathed explosive charges in novel applications. 19 4. Operation of the Safety Research Coal Mine and the Experimental Mine Objective: To continue an ongoing effort to operate and maintain two spe- cialized full-scale underground mine facilities located at Bruceton, Examples of research activities to be pursued in- clude (1) identification of explosion hazards of float coal dust layers, (2) development of practical, economical, and reliable triggered and low-coal barriers, (3) determination of the effects of large fires on mine ventilation systems, (4) evaluation of sealed mine fires and their extinguishment, and (5) determination of the effects of static loading on a bulk- head anchorage system. 5. Operation of the Twilight Mine Radiation Facility Objective ; To continue an ongoing effort to operate and maintain a specialized full-scale underground ura- nium mine for tests to be conducted by the Bureau's Spokane Research Center, Assistance With Program Management 6. Health and Safety Analysis Center (HSAC) Support Objective ; To continue an ongoing effort to provide the Bureau with easy access to statistical facts relating to employment and accident information col- lected and compiled by HSAC. 7. Research Management and Planning System (RMAPS) Support Objective ; To continue an ongoing effort to provide a dynamic information system that is capable of handling simple or complex real-time inquiries for use as a management tool or for decisionmaking. PART II. —CONTRACT RESEARCH HEALTH Respirable Dust Program Objectives ; To investigate basic dust control techniques and con- cepts aimed at preventing the generation and entrainment of respirable dust during the mining cycle. To provide new and im- proved technology for measuring and con- trolling airborne respirable dust at lev- els that meet or are below standards set by the Federal law for all mining and mineral processing operations. Control of Generated Dust 2. Evaluate Fundamental Approaches to Longwall Dust Control Objective ; To evaluate the effective- ness of available dust control technology for double-drum shearer longwall sec- tions, with special emphasis on support- generated dust and mining practices, in a coordinated, systematic program at sev- eral longwall test sections, and to make the results available to the coal mining industry. This is a continuation of an ongoing effort. Industrial Hygiene (Toxic Substances) 1. Control of Respirable Quartz on Continous Mining Sections Objective ; To evaluate sources of air- borne quartz dust and research control technologies that will assist mine oper- ators in complying with respirable dust standards that are more stringent because of quartz in the dust exceeding 5 per- cent. This is a continuation of an on- going effort. Program Objectives; To identify and control health hazards to surface and underground mines and mineral processing plants caused by toxic gases and fumes, and certain particulates produced by explosives, combustible materials, and diesel engines. To develop and evaluate new instrumentation for monitoring these substances. To develop and/or refine analytical techniques for measuring and 20 characterizing toxic substances, and investigate methods for controlling the formation and accumulation of toxic prod- ucts. To analyze alternative power sources that may have health advantages over existing mine diesels. Diesel Engine and Alternative Power Sources 1, A Clean Internal Combustion Engine for Underground Mining Machinery Objective; To determine the adequacy of the safety devices and systems of the prototype hydride-fueled mining vehicle currently being fabricated. This is a continuation of an ongoing effort. Ventilation Program Objectives: To develop venti- lation systems required to maintain a safe and healthful atmosphere conducive to efficient work output in noncoal mines. 1. Effective Face Ventilation Systems for Oil Shale Mines Objective; To develop and evalu- ate conceptual designs for large-opening face ventilation systems and to in-mine-evaluate two of these designs. This is a continuation of an ongoing effort. SAFETY Postdisaster Program Objective ; To develop the technology that will enhance the chances of miners to escape, survive, and/or be rescued following mine fire, explosion, or outbursts of gas. This involves per- sonal protection equipment for miners and rescue teams, preplanned rescue and sur- vival systems, and devices to detect, locate, and communicate with trapped miners. 1. Rescue and Mine Recovery Low-Profile, Lightweight Rescue Breathing Apparatus Objective : To develop a 2-hour, low-profile, compressed-oxygen rescue breathing apparatus suitable for use in low coal at longwall faces. This is a continuation of an ongoing effort. 2. Rescue Team Helmet Objective ; To develop a rescue team helmet that provides full head protec- tion, an integral facepiece, communi- cations, and a miner's lamp and is com- patible with the new low-profile, lightweight rescue breathing apparatus. This is a continuation of an ongoing effort. INT.-BU.OF MINES, PGH., PA. 27201 "-..^^^ / ,^v -^, ■*..*- :mM. \/ :g^\ %,<^ /'"^^■■- *- ^^ -v*^^*/ v'^v V'^'/ \-^-v v*"^v \ ■••.-.-. ." ^^''%, =: • • • \ > ■^^ V*^' < o A. A, ♦ .^"^*>^'\ <^°.'^i>- ^^"^>^%\ .^°^•^i•°- / .V ^"•^^, ' ^^-^^^ V ^°-^.^. < o f ^^# I*