Evaluation of peripheral visual performance when using incandescent and LED miner cap lamps

Illumination plays a critical role in an underground miner\u2019s safety because miners depend most heavily on visual cues to recognize hazards. Mobile mining machinery, located in the miner\u2019s peripheral field-of-view (\ub110\ub0 to about \ub160\ub0 off-axis), may pose potential pinning and striking hazards. The main objective of this research was to determine if there were peripheral visual performance improvements for the detection of moving objects when using cool-white light-emitting diode (LED) cap lamps as compared to incandescent (INC) light bulbs commonly used in miner cap lamps. The cap lamp variable of interest is the spectral power distribution (SPD); the illuminances were normalized by a diffusion filter. The second objective was to determine if age is a factor for peripheral visual performance. This is important because the workforce is aging - the average miner age is about 43 years old. Thirty subjects participated in the study; ten subjects each in the age groups of younger (18 to 25 years), middle (40 to 50 years), and older (50+ years). Visual performance was quantified by the subjects\u2019 speed and accuracy of response to detect the rotation of high-contrast (white) circular targets located 3.83 meters (m) away at -20\ub0, 40\ub0, and 50\ub0 off-axis. The speed of detection and the number of missed target rotations (accuracy) were measured. The prototype LED cap lamp results were best with a 11% to 15% improvement compared to the INC and LED cap lamps respectively. Age does appear to be a significant factor. For the middle and older age groups\u2019, target movement detection time increased 75% and 60% and the number of missed targets increased 500% and 450% respectively in comparison to the youngest age group. The results also suggest that target location is a significant factor. The subjects\u2019 target movement detection time for the 40\ub0 and 50\ub0 target movements increased 16% and 69% respectively as compared to the -20\ub0 target.2008768

Trans Soc Min Metall Explor Inc

The Illuminating Engineering Society of North America reports that an underground mine is the most difficult environment to illuminate (Rea, 2000). Researchers at the U.S. National Institute for Occupational Safety and Health (NIOSH) Office of Mine Safety and Health Research (OMSHR) are conducting ongoing studies designed to explore different lighting technologies for improving mine safety. Underground miners use different visual cues to escape from a smoke-filled environment. Primary and secondary escapeways are marked with reflective ceiling tags of various colors. Miners also look for mine rail tracks. The main objective of this paper is to compare different lighting types and ceiling tag colors to differentiate what works best in a smoke-filled environment. Various cap lamps (LED and incandescent) and lasers (red, blue, green) were compared to see which options resulted in the longest detection distances for red, green and blue reflective markers and a section of mine rail track. All targets advanced toward the human subject inside of a smoke-filled room to simulate the subject walking in a mine environment. Detection distances were recorded and analyzed to find the best cap lamp, laser color and target color in a smoke environment. Results show that cap lamp, laser color and target color do make a difference in detection distances and are perceived differently based on subject age. Cap lamps were superior to lasers in all circumstances of ceiling tag detection, with the exception of the green laser. The incandescent cap lamp worked best in the simulated smoke compared to the LED cap lamps. The green laser was the best color for detecting the tags and track compared to the red and blue lasers. The green tags were the easiest color to detect on the ceiling. On average, the track was easier for the subjects to detect than the ceiling tags.YLH8/Intramural CDC HHS/United States2015-07-31T00:00:00Z26236146PMC452199

Do light-emitting diode cap lamps enable improvements in miner safety?

Proper illumination is critical to a miner\u2019s ability to detect hazards in underground mines. Moving hazards are often located in the miner\u2019s peripheral field-of-view, while slip/trip/ fall hazards are often located in the forward field-of-view. The objective of the research described in this paper was to determine if light-emitting diodes (LEDs) improve visual performance as compared to traditional incandescent (INC) cap lamps. The research presented focuses on comparative studies of a National Institute for Occupational Safety and Health (NIOSH) prototype LED, a commercial LED and an INC camp lamp. Thirty subjects participated in these studies, with ten subjects in each of the following age groups: 18 to 25 years, 40 to 50 years and 51+ years old. Visual per\uadformance was quantified by the subjects\u2019 speed and accuracy in detecting hazards, while visual performance for disability glare was quantified by the use of contrast sensitivity tests. Results suggest that LEDs with a visible spectrum containing a higher concentration of the shorter wavelengths can enable visual performance improvements with respect to disability glare, the detection of moving hazards in the peripheral field-of-view and the detection of floor hazards in the forward field-of-view. The NIOSH prototype LED cap lamp provided the best visual performance improvements for the older age groups in every test.2009768

Int J Ind Ergon

A large proportion of non-fatal slips, trips, and falls (STFs) at surface mining facilities are associated with mobile equipment. Ingress and egress from mobile equipment can pose a fall risk to mobile equipment operators. The objective of this study was to determine mobile equipment operators' views of STF risks from mobile equipment, and to ascertain what factors, tasks, and conditions they perceive as contributing to these risks. A thematic analysis of 23 individual interviews and 2 group interviews was conducted, with 10 overarching themes identified from the transcripts. Mobile equipment operators indicated that being unable to see their feet or the ladder rungs during descent and the presence of contaminants on the ladders caused by normal operation make egress more dangerous than ingress. The flexible rails and high heights of the lower rungs identified over 40 years ago as issues for mobile equipment operators still pose a perceived STF risk. Further, the requirements of routine maintenance tasks such as oil and filter changes, greasing, and cleaning windows pose fall risks due to inadequate access and the need to carry supplies up and down equipment ladders. In addition to the mobile equipment, hazardous ground conditions and insufficient lighting were found to be key issues around the mobile equipment and in parking areas. The findings of this work indicate that mobile equipment operators feel at risk for STFs due to the design and condition of their equipment, and would like to see ladders replaced with safer stairways as the primary ingress/egress system.CC999999/ImCDC/Intramural CDC HHS/United States2020-07-01T00:00:00Z31745376PMC68634367915vault:3393

DESIGN OF ILLUMINATION SYSTEM FOR AN OPENCAST COAL MINING PROJECT–A CASE STUDY

The scientific work documented in this thesis was carried out, as a part of the research investigation, sponsored by a major coal company, to create a safe visual working environment for a mechanized opencast coal mine. The research investigations were carried out with the following objectives: conduct illumination survey & check the adequacy of lighting vis-à-vis DGMS /International standards at: Different places of work in the mine.Different HEMMs. Design of appropriate illumination systems based on illumination requirement for: Haul road,Overburden(OB) transport road,Dump yard,Moving Coal & OB faces. The illumination study was performed in Kusmunda opencast project, SECL,Bilaspur. It included an illumination survey of the existing lighting system at haul road, dump yard,coal & OB face followed by analysis & improvement measures. The lux meter used for the survey was Metravi1332. The illumination models for various working places in mine were developed using DIALux. DGMS standard for opencast mine lighting was used for assessment and design of illumination systems. Haul & dump road lighting design was done as per CIE EN13201 standard, which is internationally used for road lighting. The design models resulted in significant improvement over the existing system. Also, improvement of lux level was obtained as compared to the existing lighting system. Based on the observations design of illumination systems for the mine following recommendations have been proposed to improve the visual level in the work places and are stated below: Installation of 150W HPSV luminaires for roads not exceeding length of 1 km and 250W HPSV luminaires for length exceeding 1 km and other installation details should follow the given design.Installation of Metal Halide luminaires for coal faces and HPSV for OB faces.Luminaires should be die cast aluminum built.Truck mounted illumination system can be used instead of fixed lighting system at coal face

A Single-phase Rectifier With Ripple-power Decoupling and Application to LED Lighting

In recent years, Light-Emitting-Diode (LED) is widely used in lighting applications for its high efficacy and high reliability. However, the rectifier, which is required by the LEDs to convert the AC power from the grid into DC power, suffers from low-reliability caused by the filtering capacitor. In order to fully utilize the long operational hours of the LEDs, this thesis proposes a rectifier that has improved reliability by adding a ripple-port to eliminate the non-reliable electrolytic capacitor. The ripple-port is capable of decoupling the ripple-power inherited in a single-phase rectifier, which enables using the reliable film capacitor to replace the electrolytic capacitor. To guarantee that the ripple-port can effectively decouple the ripple-power, a closed-loop control scheme is designed and implemented in a digital controller. Simulation and experimental results show that the proposed rectifier can reduce the required capacitance by 70%, which results in a 60% increase in lifetime. The proposed ripple-port circuit can be considered as an add-on module to be integrated into the rectifiers used in applications that require long lifetime. A detailed analysis of the efficiency, cost and reliability of applying the ripple-port in LED lighting applications supports the feasibility of the proposed circuit

Optimal Roof Coverage and Identification of Potential Roof Problems in Underground Coal Mines Using LED Lighting

The popularity and implementation of light emitting diode (LED) lighting have increased drastically over recent years into both residential and industrial applications. However, due to MSHA permissibility requirements, LED lighting is not currently being fully utilized in underground coal mining. While previous research has focused on examining the benefits that LED lighting possesses over other common light sources, very few have been done to find the optimum configuration to illuminate underground excavations better for the safety of the miners. In this research, multiple experiments were conducted to evaluate the potential impacts LED lighting can have on underground mine safety. The optimal light setup that provided the most roof coverage was found to be between 5 and 7 feet of separation, which is similar to what is usually used on roof bolting machines. It was also determined that LED lighting performs well in terms of discontinuity identification compared to what is commonly used in underground coal mining. The results of this research will serve as a design parameter for lighting manufacturers to use. These tests were done to simulate possible lighting locations on a roof bolting machine, but the results can be employed for other underground equipment as well

Bibliography of communication and research products

"This publication is a compendium of NIOSH publications and reports produced during calendar year 2009. Citations are listed by category including: I. Journal Articles; II. Book Chapters; III. NIOSH Numbered Publications; IV. Abstracts/Proceedings; V. Control Technology Reports; VI. Fatality Assessment and Control Evaluation Reports; VII. Fire Fighter Fatality Investigation and Prevention Reports; and, VIII. Health Hazard Evaluation Reports. Author, keyword and National Occupational Research Agenda (NORA) priority area indexes are also included. ." - NIOSHTIC-2I. Journal articles -- II. Book chapters -- III. NIOSH numbered publications -- IV. Abstracts/Proceedings -- V. Control technology reports -- VI. Fatality assessment and control evaluation reports -- VII. Fire fighter fatality investigation and prevention reports -- VIII. Health hazard evaluation reports -- IX. Author index-- X. Keyword index -- XI. National Occupational Research Agenda (NORA) index"April 2010."Also available via the World Wide Web

NOIRS 2008

"The National Institute for Occupational Safety and Health (NIOSH) hosted the fourth National Occupational Injury Research Symposium (NOIRS) on October 21-23, 2008 at the Sheraton Station Square in Pittsburgh, Pennsylvania. NOIRS is the only forum for the presentation of occupational injury research findings, data, and methods. This symposium served numerous objectives aimed at preventing traumatic occupational injury through research and prevention. They included: 1. Presenting current research findings. 2. Fostering collaboration among researchers from a broad range of disciplines and perspectives, and exploring underutilized disciplines and topic areas. 3. Identifying best practices in the area of intervention evaluation. 4. Exploring the cost-effectiveness of injury prevention strategies and interventions. 5. Showcasing innovative and high technology approaches to research and prevention. 6. Continuing to promote the implementation of NORA. Questions that were addressed included: 1. What are the latest traumatic occupational injury research findings? 2. What are emerging problem areas in workplace trauma? 3. How is prevention through design being applied to occupational injury research and prevention? 4. What activities are being done to implement research to practice in the area of traumatic occupational injury? 5. What are the best practice intervention and prevention strategies and which strategies do not work? In what specific workplaces and under what circumstances? 6. What are the economic costs of traumatic occupational injuries and how cost-effective are the prevention strategies? 7. What are current and emerging research areas and disciplines? 8. What are the trends in traumatic occupational injury and fatality incidence? In research tools, techniques, and methods? In prevention? 9. What specific workplace risks are faced by adolescents, older adults, minority workers, non-English-speaking workers, low-literacy workers, and other special populations? 10. How can researchers and practitioners in different sectors and disciplines better collaborate and coordinate their activities to reduce traumatic occupational injuries? 11. What methods are available to assess, quantify, and compare traumatic occupational injury risks? Occupational injury researchers from all disciplines were invited to attend and share their research. We encouraged participation by all interested individuals, including: Safety researchers; Safety practitioners; Health care professionals; Administrators; Epidemiologists; Engineers; Manufacturers; Communication Researchers; Health and science communicators; Regulators; Employers; Policy makers; Insurers; Students; Advocates; Workers; Educators and trainers; and, Others interested in attending. The symposium consisted of contributed oral presentations in concurrent sessions and a poster session." - NIOSHTIC-2Available via the World Wide Web as an Acrobat .pdf file (1.30 MB, 92 p.)

Bibliography of communication and research products

"This publication is a compendium of NIOSH publications and reports produced during calendar year 2008. Citations are listed by category including: I. Journal Articles; II. Book Chapters; III. NIOSH Numbered Publications; IV. Abstracts/Proceedings; V. Control Technology Reports; VI. Fatality Assessment and Control Evaluation Reports; VII. Fire Fighter Fatality Investigation and Prevention Reports; and, VIII. Health Hazard Evaluation Reports. Author, keyword and National Occupational Research Agenda (NORA) priority area indexes are also included."- NIOSHTIC-2I. Journal articles -- II. Book chapters -- III. NIOSH numbered publications -- IV. Abstracts/Proceedings -- V. Control technology reports -- VI. Fatality assessment and control evaluation reports -- VII. Fire fighter fatality investigation and prevention reports -- VIII. Health hazard evaluation reports -- IX. Author index-- X. Keyword index -- XI. National Occupational Research Agenda (NORA) index"May 2009."Also available via the World Wide Web