The objectives for this study were twofold: (1) to determine whether the whole-body vibration application (WBV app) may effectively serve as a simple tool for monitoring WBV exposure; and (2) to assess when vehicle seats may need adjustment, repair, or replacement. Data were collected on 17 mobile mining vehicles and equipment at six surface operations. Comparing the WBV app to the Siemens/LMS reference system showed excellent correlation (r = 0.998 and 0.987, respectively) for frequency-weighted-root-mean-square acceleration (aw) and vibration dose value (VDV) normalised to an 8-hour shift. Seat performance, using the mobile app showed greater variation, yet high positive correlations (r = 0.896 and 0.936) for the aw and VDV computational methods, respectively. Hence, the WBV app demonstrates potential as a low-cost instrument to measure WBV exposures for mobile equipment operators and the capability to estimate seat performance or seat effective amplitude transmissibility (SEAT) when utilised on two iPod Touch devices. Copyright © 2021 Inderscience Enterprises Ltd.

Nonfatal injuries from slips, trips, and falls (STF) that occur at surface mines can result from inadequate lighting. Mobile equipment operators are among the occupations associated with the nonfatal incidents reported to the U.S. Mine Safety and Health Administration (MSHA). In addition, getting on/off the equipment (ingress/egress) frequently adds to the highest proportion of nonfatal incidents. Accordingly, researchers at the Pittsburgh Mining Research Division (PMRD), National Institute for Occupational Safety and Health (NIOSH) conducted a field study to investigate lighting on haul trucks and wheel loaders with regard to glare and illuminance levels recommended by the Illuminating Engineering Society (IES). The objective was to determine whether two light-emitting diode (LED) area luminaires—a Mr. Beams® (model MB390 Ultrabright) (area luminaire-1) and a NIOSH-developed Saturn (custom-designed for a mine roof bolter study) (area luminaire-2)—could complement a headlamp luminaire. Measured levels of visual tasks, with the headlamp alone and the area luminaires plus the headlamp, demonstrated that illuminance met or exceeded IES-recommended levels. Nevertheless, the area luminaires illuminated a much broader area, which is key to increasing hazard awareness. Discomfort and disability glare were lower with area luminaire-1 than with area luminaire-2. Differences in glare were more noticeable for newer models of haul trucks and loaders featuring updated ingress/egress system designs. This study demonstrates that commercially available luminaires, such as area luminaire-1, are capable of complementing headlamp lighting, and can thus improve a miner’s ability to detect and avoid STF hazards.

Researchers from the National Institute for Occupational Safety and Health (NIOSH) developed a light-emitting diode (LED) area luminaire called the Saturn and conducted a laboratory study using a Fletcher High Dual-boom Mast Feed (HDDR) roof bolting machine. The Saturn luminaire was designed to (1) enhance floor illumination to enable better detection of trip hazards in the interior spaces of a roof bolter and (2) reduce glare that has typically been an issue of concern on roof bolters. This paper reports on the results of achieving the second objective. The existing roof bolter lighting was the baseline and was compared with three versions of the Saturn luminaire relative to light intensity (100%, 75%, and 50%). Discomfort and disability glare data were obtained from 30 participants that comprised three age groups. Discomfort glare perceptions were obtained using the De Boer rating scale, and disability glare was quantified by using Mars Letter Contrast Sensitivity tests. Discomfort glare was reduced at least 3 levels with all Saturn versions. Also, a predictive model was used to estimate discomfort glare, and the results were similar. Disability glare was the least for the Saturn’s 50% intensity, and all Saturn versions had significantly less disability glare than with the baseline lighting. Veiling luminance was calculated and used as another indicator of disability glare. Veiling luminance was 28 to 42 times greater with the baseline lighting as compared with that of the Saturn lighting. Lastly, visibility levels were calculated. The Saturn versions were 4 to 6.5 times better in terms of visibility level.

Workers who operate mine haul trucks are exposed to whole-body vibration (WBV) on a routine basis. Researchers from the National Institute for Occupational Safety and Health (NIOSH) Pittsburgh Mining Research Division (PMRD) investigated WBV and hand-arm vibration (HAV) exposures for mine/quarry haul truck drivers in relation to the haul truck activities of dumping, loading, and traveling with and without a load. The findings show that WBV measures in weighted root-mean-square accelerations (aw) and vibration dose value (VDV), when compared to the ISO/ANSI and European Directive 2002/44/EC standards, were mostly below the Exposure Action Value (EAV) identified by the health guidance caution zone (HGCZ). Nevertheless, instances were recorded where the Exposure Limit Value (ELV) was exceeded by more than 500 to 600 percent for VDVx and awx, respectively. Researchers determined that these excessive levels occurred during the traveling empty activity, when the haul truck descended down grade into the pit loading area, sliding at times, on a wet and slippery road surface caused by rain and overwatering. WBV levels (not normalized to an 8-h shift) for the four haul truck activities showed mean awz levels for five of the seven drivers exceeding the ISO/ANSI EAV by 9-53 percent for the traveling empty activity. Mean awx and awz levels were generally higher for traveling empty and traveling loaded and lower for loading/dumping activities. HAV for measures taken on the steering wheel and shifter were all below the HGCZ which indicates that HAV is not an issue for these drivers/operators when handling steering and shifting control devices.

The development and testing of ergonomics and safety audits for small and bulk bag filling, haul truck, and maintenance and repair operations in coal preparation and mineral processing plants found at surface mine sites is described. The content for the audits was derived from diverse sources of information on ergonomics and safety deficiencies including: analysis of injury, illness, and fatality data and reports; task analysis; empirical laboratory studies of particular tasks; field studies and observations at mine sites; and maintenance records. These diverse sources of information were utilized to establish construct validity of the modular audits that were developed for use by mine safety personnel. User and inter-rater reliability testing was carried out prior to finalizing the audits. The audits can be implemented using downloadable paper versions or with a free mobile NIOSH-developed Android application called ErgoMine. Practitioner Summary The methodology used to develop ergonomics audits for three types of mining operations is described. Various sources of audit content are compared and contrasted to serve as a guide for developing ergonomics audits for other occupational contexts.

Falls from mobile equipment are reported at surface mine quarry operations each year in considerable numbers. Research shows that a preponderance of falls occur while getting on/off mobile equipment. Contributing factors to the risk of falls include the usage of ladders, exiting onto a slippery surface, and foot or hand slippage. Balance issues may also contribute to fall risks for mobile equipment operators who are exposed to whole-body vibration (WBV). For this reason, the National Institute for Occupational Safety and Health, Office of Mine Safety and Health Research conducted a study at four participating mine sites with seven haul truck operators. The purpose was to ascertain whether WBV and hand-arm vibration (HAV) exposures for quarry haul truck operators were linked to short-term decreases in performance in relation to postural stability, touch sensation threshold, and grip strength that are of crucial importance when getting on/off the trucks. WBV measures of frequency-weighted RMS accelerations (wRMS) and vibration dose value (VDV), when compared to the ISO/ANSI standards, were mostly below levels identified for the Health Guidance Caution Zone (HGCZ), although there were instances where the levels were within and above the specified Exposure Action Value. Comparably, all mean HAV levels, when compared to the ISO/ANSI standards, were below the HGCZ. For the existing conditions and equipment, no significant correlation could be identified between the WBV, HAV, postural stability, touch sensation threshold, and grip strength measures taken during this study.

Underground coal mine explosions, such as the January 2006 Sago mine disaster, have dramatically demonstrated the need to provide mine refuge alternatives for miners who are unable to exit the mine and are forced to take refuge during mine disasters or emergencies. | The Mine Improvement and New Emergency Response (MINER) Act of 2006 requires that underground coal operators include refuge alternatives (RAs) in their Emergency Response Plans. Mines presently use three types of refuge alternatives: mobile steel, mobile inflatable tent and built-in-place (BIP). | Considering the importance of equipping RAs well for emergencies, this article reviews the Mine Safety and Health Administration (MSHA) regulations for food, water and waste disposal/sanitation in RAs. Information received from RA manufacturers is presented on food, water, and sanitation products and methods provided in their RAs. Issues that may arise from using these products are also discussed, along with possible solutions.

To further assess vibration exposure on haul trucks (HTs) and front-end wheel loaders (FELs), follow-up investigations were conducted at two US crushed stone operations. The purpose was to: 1) evaluate factors such as load/no-load conditions, speed, load capacity, vehicle age, and seat transmissibility relative to vibration exposure; 2) compare exposure levels with existing ISO/ANSI and EUGPG guidelines. Increasing HT speed increased recorded vibration at the chassis and seat as expected. Neither vehicle load nor vehicle speed increased transmissibility. Increasing HT size and age did show transmissibility decreasing. HT dominant-axis wRMS levels (most often the y-axis, lateral or side-to-side direction) were predominantly within the health guidance caution zone (HGCZ). However, several instances showed vibration dose value (VDV) above the exposure limit value (ELV) for the ISO/ANSI guidelines. VDV levels (all dominant x-axis or fore-aft) were within and above the HGCZ for the EUGPG and above the HGCZ for ISO/ANSI guidelines.

This paper describes an experiment to examine whether a visual warning system can improve detection of moving machine hazards that could result in struck-by or pinning accidents. Thirty-six participants, twelve each in one of three age groups, participated in the study. A visual warning system capable of providing four different modes of warning was installed on a continuous mining machine that is used to mine coal. The speed of detecting various machine movements was recorded with and without the visual warning system. The average speed of detection for forward and reverse machine movements was reduced by 75% when using the flashing mode of the visual warning system. This translated to 0.485 m of machine travel for the fast speed condition of 19.8 m/min, which is significant in the context of the confined spaces of a mine. There were no statistically significant differences among age groups in the ability to detect machine movements for the visual warning modes in this study. The visual warning system shows promise as a safety intervention for reducing struck-by or pinning accidents involving continuous mining machines. The methods and results of this study could be applied to other moving machinery used in mining or other industries where moving machinery poses struck-by or pinning hazards.

Researchers at the National Institute for Occupational Safety and Health (NIOSH) are investigating different lighting technologies with the objective of improving mine safety. This paper presents the results from an ongoing study that compares discomfort glare for different light-emitting diode (LED) cap lamps using the de Boer glare rating scale. The cap lamps tested included two commercially-available LED cap lamps and one NIOSH prototype LED cap lamp tested at three different illumination levels. Prior research indicated that the NIOSH prototype enabled much better visual performance as compared to other LED cap lamps. It uses three LEDs that produce multiple illumination areas in comparison to commercially-available cap lamps that use one LED and projects a narrow spot pattern. Across subjects and cap lamp test conditions, measured illuminances (averaged at both eyes) varied from 0.62 to 3.73 lx, whereas the de Boer glare ratings varied from 4.86 to 7.71. An analysis of variance based on 15 subjects indicated a significant difference in the discomfort glare due to cap lamps (F4, 52 = 18.01, p 0.001). Post hoc tests indicate that one of the commercially available cap lamps exhibited lower discomfort scores, with no statistically significant differences detected between the others. Thus, the NIOSH prototype cap lamp does not cause excessive discomfort glare yet enables better visual performance. 2011 IEEE.

This study examines stress transmitted to anatomic landmarks of the knee (patella, combined patella tendon and tibial tubercle) while in static kneeling postures without kneepads and while wearing two kneepads commonly worn in the mining industry. Ten subjects (7 male, 3 female) simulated postures utilized in low-seam mines: kneeling in full flexion; kneeling at 90 degrees of knee flexion; and kneeling on one knee while in one of three kneepad states (no kneepads, non-articulated kneepads, and articulated kneepads). For each posture, peak and mean pressure on the anatomic landmarks of the knee were obtained. The majority of the pressure was found to be transmitted to the knee via the combined patellar tendon and tibial tubercle rather than through the patella. While the kneepads tested decreased the maximum pressure experienced at the combined patellar tendon and tibial tubercle, peak pressures of greater than 25psi were still experienced over structures commonly injured in mining (e.g. bursa sac - bursitis/Miner's Knee). The major conclusion of this study is that novel kneepad designs that redistribute the stresses at the knee across a greater surface area and to other regions of the leg away from key structures of the knee are needed.

In a systematic study, the National Institute for Occupational Safety and Health (NIOSH) evaluated seat designs in low- and mid-seam shuttle cars during production operations at two underground coal mines in southern West Virginia. The purpose was to support, with additional data, earlier findings that NIOSH ergonomic seat designs (featuring viscoelastic foam padding and lower-back support) may help reduce health risks to operators of coal mine shuttle cars. Eight shuttle car operators evaluated seven seat designs (one already in use in each vehicle and five NIOSH designs) relative to perceived and measured whole-body vibration (WBV) exposure (including vehicle jarring/jolting) and discomfort. Operators' perceptions using a visual analog scale (VAS) and questionnaire ratings were compared with International Standards Organization (ISO) 2631-1:1985 fatigue-decreased proficiency (FDP) limits and measured WBV levels on low- and mid-seam shuttle cars. Objective and subjective data results indicated that NIOSH seat designs (with added adjustability, lower-back support and improved seat padding) performed better to reduce vehicle jarring/jolting levels and that shuttle car operators favored them over existing seat designs. The NIOSH low- and mid-seam shuttle car seats showed 45 to 77 percent better performance in FDP and 9 to 60 percent better performance overall in operators' ratings. Considering the VAS results for low- and mid-seam shuttle cars under no-load conditions, operators rated the level of jarring/jolting 18 to 89 percent lower with the NIOSH seats. Reductions in measured vehicle jarring/jolting were 19 to 46 percent for the three-directional vector sum accelerations relative to the existing seats on the low- and mid-seam shuttle cars. Questionnaire responses indicated that operators for both shuttle car models rated NIOSH seat designs as more comfortable overall. Vehicle operators most frequently suggested adding armrests to improve the seats on the mid-seam shuttle car. A suggested improvement for the low-seam shuttle car was to make the seat a better fit for the operator compartment, which would enhance clearance between the operator and vehicle controls and allow for better seat adjustment and operator visibility.