Data & statistics

Results of Direct-Method Determination of the Gas Content of U.S. Coalbeds (PDF, 4676 KB, 1986)
This report presents a data base of gas content data. The data are presented in tabular form, by coalbed name and state. The components of the total gas content (lost, desorbed, and residual gas) are given. Location (state and county), sample depth, coalbed or formation name, and coal rank are included for geographic and geology identification. Combined with geologic and engineering studies, these data can be used as a basis for a preliminary estimate of mine ventilation requirements, and to determine whether methane drainage in advance of mining should be considered.

History

Development of Coal Mine Face Ventilation Systems During the 20th Century (PDF, 2404 KB, 2007-08)
This article focuses on U.S. Bureau of Mines (USBM) and NIOSH research to examine factors that had a significant influence on mine face ventilation design during the past century.

Factors Affecting the Development of Mine Face Ventilation Systems in the 20th Century (PDF, 843 KB, 2007-02)
During the 20th century, the increased emphasis on worker health and safety and the advent of new mining equipment and methods led to many changes in mine face ventilation practices. This paper examines factors that had a significant influence on mine face ventilation design during the past century.

Software

AQE - Air Quantity Estimator
The Air Quantity Estimator provides a starting point for estimating the air quantity needed to dilute diesel particulate matter in underground large opening mines.

Guides

Guidelines for the Prediction and Control of Methane Emissions on Longwalls (PDF, 3861 KB, 2008-03)
In this report, several practical guidelines are recommended for controlling longwall coalbed methane. All predictions are based on determinations made for the Pittsburgh Coalbed in southwestern Pennsylvania.

Models

Modeling and Prediction of Ventilation Methane Emissions of U.S. Longwall Mines Using Supervised Artificial Neural Networks (PDF, 844 KB, 2008-02)
This study proposes a principle component analysis (PCA) and artificial neural network (ANN)-based approach to predict the ventilation methane emission rates of U.S. longwall mines.

Measurement & analysis

Advances in Grid-Based Numerical Modeling Techniques for Improving Gas Management in Coal Mines (PDF, 462 KB, 2008)
This paper summarizes the modeling efforts conducted by NIOSH in the U.S. and CSIRO in Australia to address various gas management issues encountered in longwall mines using the application of computational fluid dynamics (CFD) and numerical reservoir modeling for gob inertization and gas control for spontaneous combustion, pre-mining degasification of coalbeds, gob gas venthole design and performance evaluation in longwalls, and gas management during development mining.

Analysis and Prediction of Longwall Methane Emissions: A Case Study in the Pocahontas No. 3 Coalbed, VA (PDF, 1919 KB, 1997)
Increasing longwall panel dimensions, particularly face width in gassy coalbeds, may result in unexpected increases in methane emissions. To investigate this problem, continuous longwall face emission monitoring studies were conducted at two adjacent mines operating in the Pocahontas No. 3 Coalbed, where longwall faces were to be extended from 229 to 305 m (750 to 1,000 ft).

Artificial Neural Networks to Determine Ventilation Emissions and Optimum Degasification Strategies for Longwall Mines (PDF, 169 KB, 2008)
This study proposes a principle component analysis (PCA) and artificial neural network (ANN) approach to predict the ventilation methane emission rates of U.S. longwall mines and the optimum combination of degasification boreholes based on the given characteristics of the mine.

Characterization of Gas Flow in Longwall Gobs: Pittsburgh Coalbed, PA (PDF, 175 KB, 1999)
Investigation of the geologic and mining factors influencing the migration of longwall gob gas with a goal to optimize methane drainage strategies to reduce the volume of gob gas that reaches the underground workplace.

Coal Bed Discontinuity Effects on the Production of Degasification Boreholes and on Emissions During Longwall Mining (PDF, 571 KB, 2008)
This study presents a numerical investigation of geological discontinues in the coalbed using reservoir simulations of the effects of partings and permeability facies and lithotype changes on the production performances of vertical and horizontal degasification boreholes, as well as the emissions during longwall operations.

Comparison of Methane Concentrations at a Simulated Coal Mine Face During Bolting (PDF, 145 KB, 1999-04)
An evaluation of strategies for monitoring methane levels during roof bolting in an extended cut entry.

A Comparison of Methods: Dynamic Versus Hydrostatic Testing of Mine Ventilation Seals (PDF, 785 KB, 2008-09)
This paper contrasts the full-scale explosion and hydrostatic testing of mine seals using a simple dynamic system model and principles.

Computational Fluid Dynamics Study on the Ventilation Flow Paths In Longwall Gobs (PDF, 599 KB, 2006)
This paper focuses on the flow patterns within the gob under three different ventilation systems: one-entry and two-entry bleederless systems, as well as a three-entry bleeder system.

Development and Application of Reservoir Models and Artificial Neural Networks for Optimizing Ventilation Air Requirements in Development Mining of Coal Seams (PDF, 1131 KB, 2007-11)
This study presents an approach using coalbed methane reservoir modeling and an artificial neural network (ANN) design for prediction and optimization of methane inflows and ventilation air requirements to maintain methane concentrations below statutory limits.

Development and Application of Reservoir Models for the Evaluation and Optimization of Longwall Methane Control Systems (PDF, 264 KB, 2006)
This paper describes the development of reservoir models for the longwall mining environment and their application for investigating the influence of various completion design parameters on the methane drainage effectiveness of gob gas ventholes.

Development of New Protocols to Evaluate the Transverse Loading of Mine Ventilation Stoppings (PDF, 338 KB, 2006-06)
A new protocol based on rigid arch loading of the structure is proposed to determine the true transverse load capacity of block stoppings. The rigid arch tests have shown that the load capability is dependent on the physical properties of the block and geometric properties of the wall, not the sealant.

Effects of Water Sprays and Scrubber Exhaust on Face Methane Concentrations (PDF, 320 KB, 2001)
Research to determine how machine-mounted water sprays and a scrubber interact to reduce methane levels and what spray configurations provide the best face ventilation when used with a scrubber.

Evaluating Factors Affecting the Performance of Three-Axis Ultrasonic Anemometers (PDF, 215 KB, 2004-05)
Provides guidelines for more effective use of the ultrasonic anemometer.

Evaluating Ventilation Parameters of Three Coal Mine Gobs (PDF, 1208 KB, 1986)
The Bureau of Mines used sulfur hexafluoride (sf6) tracer gas to evaluate the effectiveness of gob ventilation and/or sealing practices at three coal mines, each having different problems associated with their mined-out areas. The purpose of these ventilation studies was to better understand whether current techniques employed for ventilation or sealing are successful at minimizing the potential for gob fires and explosions.

Evaluation of the Relative Importance of Coalbed Reservoir Parameters for Prediction of Methane Inflow Rates During Mining of Longwall Development Entries (PDF, 663 KB, 2008-09)
This study presents a reservoir modeling approach to investigate the relative effects of different coalbed parameters on the migration of methane into development entries. This work shows that coupling reservoir simulations with linear modeling yields a technique that can be applicable to different coalbeds.

Explosion Evaluation of Mine Ventilation Stoppings (PDF, 233 KB, 2006-06)
NIOSH and the Mine Safety and Health Administration (MSHA) conducted joint research to evaluate explosion blast effects on mine ventilation stoppings at the NIOSH Lake Lynn Experimental Mine. The LLEM data showed that a total pressure of 52 kPa (7.6 psi) destroyed the solid-concrete-block stopping, ~36 kPa (~5.2 psi) destroyed the hollow-core concrete-block stopping, and 9 kPa (1.3 psi) destroyed the steel panel stopping.

Impact of Unbalanced Intake and Scrubber Flows on Face Methane Concentrations (PDF, 846 KB, 1997)
Research was conducted to investigate how ventilation of a mining face is affected when scrubber flow is greater or less than intake flow. Tests were conducted in a full-scale surface test gallery built to simulate a mining entry with a continuous mining machine at the face. Increasing scrubber flow resulted in lower methane levels even when scrubber flow was much greater than intake flow.

Implications of Recent NIOSH Tracer Gas Studies on Bleeder and Gob Gas Ventilation Design (PDF, 427 KB, 2000)
Describes research at a Pittsburgh Coalbed longwall mine to evaluate and optimize bleeder ventilation and gob gas venthole longwall methane control systems.

Measurement of Airflow in a Simulated Underground Mine Environment Using an Ultrasonic Anemometer (PDF, 461 KB, 2004)
Reports on a test system and computer program developed for using a three-axis ultrasonic anemometer to measure airflow in a simulated mine entry.

Methods to Determine The Status of Mine Atmospheres - An Overview (PDF, 158 KB, 2006)
This paper serves as an overview to remind and/or instruct readers about gas-sampling methodologies and gas analyses to assist in determining the status of underground atmospheres.

Methods to Determine the Status of Mine Atmospheres - an Overview (PDF, 173 KB, 2006)
This paper serves as an overview to remind and/or instruct readers about gas-sampling methodologies and gas analyses to assist in determining the status of underground atmospheres.

Mine Face Ventilation: A Comparison of CFD Results Against Benchmark Experiments for the CFD Code Validation (PDF, 707 KB, 2007-10)
To transfer CFD expertise to analyze and design a face-ventilation system, a comprehensive validation study of current CFD tools against mining-related benchmark experiments is required. This study was dedicated to the methane behavior in an empty (containing no equipment) face area with a blowing curtain and a 10.7-m (35-ft) setback. The authors present and discuss computer-simulation data and compare them with data collected during laboratory studies of current CFD tools against mining-related benchmark experiments at the NIOSH lab.

NIOSH Research for Monitoring and Controlling Methane at U.S. Underground Coal Mining Operations (PDF, 261 KB, 2008)
This work by NIOSH has modelled the impacts of borehole pattern and design and the effects of increasing face length on gob gas venthole performance.

Numerical Analysis of the Impact of Longwall Panel Width on Methane Emissions and Performance of Gob Gas Ventholes (PDF, 353 KB, 2005)
NIOSH has initiated a reservoir modeling effort to better understand the interaction of the various geotechnical factors influencing gas flow within and to the underground longwall mining environment. A focus of this modeling effort has been (1) the prediction of the incremental amount of methane emissions to be expected due to increasing longwall panel widths and (2) optimizing gob gas venthole completion practices to capture more of the gas in the subsided strata above longwall panels before it can enter the ventilation system of the underground workplace.

Numerical Analysis of the Influence of In-Seam Horizontal Methane Drainage Boreholes on Longwall Face Emission Rates (PDF, 1223 KB, 2007-09)
This study investigates different horizontal methane drainage borehole patterns, borehole lengths, and degasification times prior to and during panel extraction to evaluate their effectiveness in reducing methane emissions using a dynamic 3D reservoir modeling of a 381-m wide longwall panel operating in the Pittsburgh coalbed.

A Numerical Evaluation on the Effects of Impermeable Faults on Degasification Efficiency and Methane Emissions During Underground Coal Mining (PDF, 1527 KB, 2008-09)
This study uses reservoir simulations to illustrate the effects of impermeable faults, with and without throws, on the production performance of vertical and horizontal degasification boreholes and presents the effects and the impacts of impermeable faults on methane emissions due to an advancing coal face.

Predicting Methane Emissions from Longer Longwall Faces by Analysis of Emission Contributors (PDF, 186 KB, 2006-06)
NIOSH conducted a longwall methane emission and mining time study at a mine in the Pittsburgh Coalbed to access the methane emission consequences of mining a longer face. Based on the results, site-specific mathematical formulas and constants were developed to characterize four longwall emission contributors. The formulas were then applied to longer longwall face mining scenarios to predict methane emissions from these faces.

Prediction of Longwall Methane Emissions and the Associated Consequences of Increasing Longwall Face Lengths: A Case Study in the Pittsburgh Coalbed (PDF, 176 KB, 2006-06)
NIOSH conducted a study to characterize and quantify the methane emissions resulting from increasing face lengths in the Pittsburgh Coalbed. The goal was to provide the mine operator with a method to predict the increase in methane emissions from the longer faces for incorporation of additional methane control capacity into the mine planning process, if necessary.

Reservoir Simulation-Based Modeling for Characterizing Longwall Methane Emissions and Gob Gas Venthole Production (PDF, 2787 KB, 2007-07)
This paper presents the development and results of a comprehensive, "dynamic," three-dimensional reservoir model of a typical multi-panel Pittsburgh coalbed longwall mine. Results presented in this paper include a simulation of gas flow patterns from the gas-bearing zones in the overlying strata to the mine environment, as well as the influence of completion practices on optimizing gas production from gob gas ventholes.

Safety Concerns Associated With the Use of Electrically Powered Haulage to Remove Workers from Mines During Main Fan Stoppages (PDF, 372 KB, 2002)
The roles of main mine fans in underground mines are to induce airflow and continuously remove hazardous gases and dust. While most larger mines use multiple fans to accomplish these tasks, many smaller mines employ only a single fan. This paper concentrates on those mines having only one fan to provide ventilation needs.

Static and Dynamic Loads in Ore and Waste Rock Passes in Underground Mines (PDF, 572 KB, 1999)
This paper describes research to improve safety during transport of ore and waste in underground mines.

Strengthening Existing 20-psi Mine Ventilation Seals With Carbon Fiber-Reinforced Polymer Reinforcement (PDF, 7610 KB, 2008-01)
This report discusses the testing and full-scale evaluations of a recently developed carbon fiber-reinforced polymer (CFRP) reinforcement technique for upgrading existing mine ventilation seals to withstand an explosion pressure of 50 psi or greater which were conducted in the NIOSH Pittsburgh Research Laboratory´s Lake Lynn Experimental Mine (LLEM) near Fairchance, PA.

Swelling-Induced Volumetric Strains Internal to a Stressed Coal Associated with CO₂ Sorption (PDF, 1547 KB, 2007-11)
This paper discusses the spatio-temporal volumetric strains in a consolidated Pittsburgh seam coal sample which were evaluated while both confining pressure and carbon dioxide CO₂ pore pressure were evaluated.

Technology News 499 - Using Propeller Fans to Improve Ventilation in Large-Entry Stone Mines (PDF, 152 KB, 2002-12)
This Tech News reports on how the use of propeller fans can significantly improve the ventilation in large entry stone mines due to their efficiency at lower pressures and less required horsepower.

Use of Infrared Sensors for Monitoring Methane in Underground Mines (PDF, 393 KB, 2008)
This paper describes research conducted to compare the performance, including response time and accuracy, of selected instruments using infrared and catalytic sensors.

Using Ultrasonic Anemometers to Evaluate Face Ventilation Conditions (PDF, 390 KB, 2007)
The fact that methane ignitions continue to occur at the mining face indicates that monitoring with machine-mounted methanometers does not always indicate the presence of high methane concentrations. Methane concentrations at the face change quickly due to changes in airflow. By measuring these changes in airflow, it may be possible to predict changes in face methane levels more quickly. The effects of changes in airflow direction and turbulence on instrument readings are discussed, and guidelines are given for selecting the type of instruments to be used for monitoring airflow near the mining face.

Using Ultrasonic Anemometers to Evaluate Factors Affecting Face Ventilation Effectiveness (PDF, 1764 KB, 2006-01)
A test system was developed at NIOSH's ventilation test gallery to measure airflow using a three-axis ultrasonic anemometer. The gallery was used to simulate face airflow conditions in underground mines having a blowing curtain. Airflow data were used to draw airflow profiles for different curtain setback distances, intake flow quantities, and entry widths. In addition, methane was released at the face, measured at the sampling locations, and displayed as methane distributions in the areas between the curtain and the face.

Ventilating the Box Cut of a Two-Pass 40-ft Extended Cut (PDF, 468 KB, 1999-07)
Describes a NIOSH study of how much ventilation air reaches the end of a 40 foot box cut. Tests were run to determine how much ventilation air reaches the end of the box cut with the continuous miner at three locations in the 40-ft two-pass extended cut mining sequence; at the end of the 40-ft box cut, at the start of the 40-ft slab cut, and 6.1 m (20 ft) into the slab cut.

Case studies

The Borehole Monitoring Experiment: Field Measurements of Reservoir Conditions and Responses in Longwall Panel Overburden During Active Mining (PDF, 459 KB, 2008-06)
This paper describes the results of a NIOSH borehole monitoring experiment (BME) on an active longwall panel.

Raising the Bar of Ventilation for Large-Opening Stone Mines (PDF, 420 KB, 2004)
Describes the results of a case study where NIOSH demonstrates that significant increases in total mine airflow can be achieved and the ventilation improved in a large-opening stone mine by replacing an axial-vane mine fan with two 12-ft diameter propeller fans and adding a line of stoppings.

Engineering controls

Control and Monitoring of Gas in Blind Auger Headings (PDF, 953 KB, 1997)
Deeper surface mining and deeper highwall penetration depths have lead to more frequent encounters with methane gas. While this coal is remotely mined from the surface, underground ignitions of methane have propagated to the surface and injured miners. Methods described in this paper show how this hazard can be correctly monitored and controlled for auger type highwall mining machines.

Designs for Rapid In-Situ Sealing (PDF, 2280 KB, 2003)
Reports on NIOSH full-scale experiments to evaluate the explosion-resistant characteristics of several new seal designs for rapid deployment during mine emergencies.

Effect of Scrubber Operation on Airflow and Methane Patterns at the Mining Face (PDF, 441 KB, 2006-06)
Tests were conducted in a full-scale ventilation gallery with a model mining machine that simulated airflow created by a dust scrubber. The results showed that operation of machine-mounted scrubbers improved face ventilation when blowing ventilation is used by increasing both the intake flow and the quantity of air reaching the face.

Effect of Water Sprays on Airflow Movement and Methane Dilution at the Working Face (PDF, 380 KB, 2006-06)
Tests were conducted in a full-scale ventilation gallery to determine the influence of mining machine-mounted water sprays on airflows and methane concentrations at the face when blowing ventilation systems are used. Test results using different spray arrangements and water pressures showed that operation of the machine-mounted sprayers can improve face ventilation effectiveness by increasing the velocity of airflow moving toward and away from the face. The improved ventilation resulted in reduced methane levels near the face.

The Effects of Ventilation Controls and Environmental Cabs on Diesel Particulate Matter Concentrations in Some Limestone Mines (PDF, 311 KB, 2008)
In this investigative study NIOSH measured for sub-micrometer elemental carbon (EC) using two types of control technologies (ventilation and cabs) which are being implemented in limestone mines.

Explosion Hazards From Methane Emissions Related to Geologic Features in Coal Mines (PDF, 799 KB, 2008-04)
This report presents a historical framework detailing the impact of geologic features on excess gas emissions and resultant mine explosions. It also provides operators with specific information on recognizing and alleviating potential hazards from methane emissions related to these geologic features.

Fan Selection For Large-Opening Mines: Vane-Axial Or Propeller Fans - Which To Choose? (PDF, 310 KB, 2006-06)
The flow characteristics of both vane-axial and propeller fans were investigated and tested at four large-opening mines to assess the effects of fan location on recirculation and entrainment. Either fan type can be used for most auxiliary applications. However, this research has shown that the optimum placement and use criteria for propeller fans differ from those promulgated by the U.S. Bureau of Mines for vane-axial fans.

Handbook for Methane Control in Mining (PDF, 4495 KB, 2006-06)
This handbook describes effective methods for the control of methane gas in mines and tunnels. It assumes the reader is familiar with mining. The first chapter covers facts about methane important to mine safety, such as the explosibility of gas mixtures. The second chapter covers methane sampling, which is crucial because many methane explosions have been attributed to sampling deficiencies. Subsequent chapters describe methane control methods for different kinds of mines and mining equipment, primarily for U.S. coal mines.

Jet Fan Ventilation in Very Deep Cuts - A Preliminary Analysis (PDF, 1756 KB, 1992)
This report investigates that application of jet fans to ventilate cuts that extend beyond 40 feet. The results of tests involving a jet fan in a 90 foot entry, its benefits and potential problems are discussed.

Maximizing the Ventilation of Large-Opening Mines (PDF, 229 KB, 2006-06)
NIOSH research suggest that by incorporating ventilation planning into the mine planning process, using propeller fans, developing new stopping materials and construction methods, and using long pillars to eliminate crosscuts where possible, the ventilation of large-opening mines can be significantly improved.

A Methodology for Determining Gob Permeability Distributions and its Application to Reservoir Modeling of Coal Mine Longwalls (PDF, 1146 KB, 2007)
Methane can be a significant hazard in coal mine longwalling operations and extensive methane mitigation techniques are employed by coal mine operators. Reservoir modeling techniques are used to better understand the liberation and migration of methane from the surrounding rocks towards the mine ventilation system. The caved rock behind the advancing longwall face, known as the gob, can contain high void ratios, providing high permeability flow paths to the methane. The gob is progressively compacted by the weight of the overburden, resulting in a reduction in the void ratio and associated permeability. Estimating the permeability distribution within the gob poses challenges due to its complexity. The authors have developed a new methodology to determine both horizontal and vertical variations in the permeability of the gob. The resulting three-dimensional permeability distribution in the gob is then transferred to a reservoir model. The paper demonstrates the application of the method and shows that reasonable results are obtained when compared to empirical experience and measurements.

NIOSH Ventilation Research Addressing Diesel Emissions and Other Air Quality Issues in Nonmetal Mines (PDF, 2760 KB, 2002)
Discusses current NIOSH research to improve mine ventilation and mine air quality, particularly for large opening mines.

Novel Stopping Designs for Large-Opening Metal/Nonmetal Mines (PDF, 202 KB, 2006-06)
The Super Stopping is designed as a long-term permanent stopping for use in the main entries of the mine, while the EZ-Up Curtain Stopping, although very durable, is designed more for portability and ease of installation. This paper describes the design, materials, and construction methods used for these stoppings, as well as their performance and durability when subjected to tests simulating actual production face blast pressures.

Practical Techniques to Improve the Air Quality in Underground Stone Mines (PDF, 1680 KB, 2002-10)
Overview of a variety of techniques and methods that can be used to improve the air quality in underground stone mines.

Reducing Respirable Dust Concentrations at Mineral Processing Facilities Using Total Mill Ventilation Systems (PDF, 876 KB, 1993)
The design and evaluation of two total mill ventilation systems are described. Both systems proved to be very effective at reducing respirable dust levels in a cost-effective manner, were easy to install, and required minimal maintenance.

Reservoir Modeling-Based Prediction and Optimization of Ventilation Requirements During Development Mining in Underground Coal Mines (PDF, 146 KB, 2008)
This NIOSH study presents an approach for prediction of methane inflow rates using coalbed methane reservoir modeling which can be used to limit the methane concentrations occurring as a result of the influences of various coalbed and operational parameters.

Reverse Performance Characteristics of Main Mine Fans (PDF, 1655 KB, 1983-08)
Laboratory and field tests of vane axial main mine fans in the 7- to 9-ft diameter size range were conducted to establish forward and reverse performance characteristics under controlled conditions and at typical mine installations.

Study of the Effects of Scrubber Operation on the Face Ventilation (PDF, 307 KB, 2008)
This paper describes the effect of machine-mounted dust scrubbers on the performance of face ventilation systems using extended-cut mining with a blowing curtain.

Technology News 437 - Total Mill Ventilation System for Mineral Processing Facilities (PDF, 66 KB, 1994-05)
This Tech News reports on the successful application of total mill ventilation systems to reduce respirable dust concentrations and comply with federal regulations regarding respirable dust

Technology News 472 - Ventilation of a 40-Foot, Two-Pass, Extended Cut (PDF, 56 KB, 1998-05)
This Tech News reports on the evaluation of the air quantity reaching the face of a 40 foot box cut during a two-pass extended cut sequence.

Ventilation Planning Layouts for Large Opening Mines (PDF, 3260 KB, 2004-02)
Describes three alternative ventilation models for use in large opening underground mines with respect to their use in mines of various levels of development.

Administrative controls

Using Mine Planning and Other Techniques to Improve Ventilation in Large-Opening Mines (PDF, 529 KB, 2008)
This paper describes NIOSH research demonstrating that the ventilation of large-opening mines improves significantly by including ventilation requirements in the mine planning process and implementing some practical techniques during mining.

Training exercises

Cutthrough Ventilation Arrangement
Three shifts on two sections are driving entries 4,800 feet from the mains to form a retreating longwall panel. The mine is very gassy. One section is about to cut through to the other. A number of problems develop. You need to make sure the cutthrough proceeds safely and that the ventilation for both sections remains adequate. As the problem develops, other miners make errors. If you do not correct them, lives may be lost.

Lingering Smoke Exercise
You are one of three scoop operators. During the first part of the shift an entry was shot and partly loaded. One of the other scoop operators, Speedy, has complained that he was dizzy and sick to his stomach. Otherwise, the shift has gone on as usual. You reenter the mine after lunch and notice that some smoke is still hanging. You are worried that the ventilation may not be adequate. Soon the two scoop operators, Speedy and Chester, who are at the face, go down. You must decide what to do to help them.

Smoke on the Section
Big Tim and Cecil are working on a super section. Cecil is in #1 entry (return air course) at the face replacing bits on a continuous miner when heavy smoke comes down on them from somewhere on the section. Cecil has a filter self-rescuer. Tim left his in #8 entry. Cecil has to find a way to help Tim plan a good route to travel through the smoke to warn others and get help to locate and fight the fire.

Delta Mine Cutthrough
Planned cutthroughs from one mine section to another are underway over a period of several days and three shifts as a retreating long wall panel is being set up. The mine liberates large quantities of methane. As the work progresses there are many points at which serious errors in communication, ventilation, and work procedures could develop. You must analyze the situation, identify and correct problems, and make sure the ventilation remains adequate throughout the procedure. (The exercise is based on an actual mine disaster in which seven miners died.) Practice is provided in the critical, planning, problem recognition, judgment and decision making skills needed to cope with a complex cutthrough procedure and the major ventilation changes that may result. This paper and pencil exercise requires short, written answers and modifications to mine maps.

Laboratories

Full Scale Face Ventilation Gallery
Evaluation of the effectiveness of face ventilation systems for removing and diluting methane gas liberated at the face and sampling methodologies used to assess face methane levels.