Why Do Haul Truck Fatal Accidents Keep Occurring?

Powered haulage continues to be a large safety concern for the mining industry, accounting for approximately 50% of the mining fatal accidents every year. Among these fatal accidents, haul-truck-related accidents are the most common, with 6 of 28 and 6 of 27 fatal accidents occurring in 2017 and 2018, respectively. To better understand why these accidents continue to occur and what can be done to prevent them, researchers reviewed the 91 haul-truck-related fatal accidents that occurred in the USA from 2005 to 2018 and performed bow-tie analyses using the final reports published by the Mine Safety and Health Administration. The analyses explore the context of the accidents with a focus on the initiating event, event outcome, hazards present, and possible preventative and mitigative controls. Overall, the vast majority of the accidents resulted in a haul truck colliding with the environment, and the majority of these events were initiated by loss of situational awareness or loss of control. The majority of the hazards were related to design and organizational controls. The results of this study suggest a need to investigate operator decision-making and organizational controls and to focus on improving design and operation controls such as mine design and operational procedures.

Whole-body vibration associated with underground coal mining equipment in Australia.

Environmental and logistical difficulties associated with obtaining whole-body vibration measurements from mobile equipment during operation in underground coal mines have hampered attempts to assess the potential vibration exposures associated with the use of such equipment. An alternative measurement technique was used to gather data from mobile equipment during normal operation at three low-methane coal mines and to estimate the possible magnitude of benefit of three control measures. 188 long duration measurements were obtained from shuttle cars (N = 142, median measurement duration = 3.2 h); personnel transport (N = 24, median measurement duration = 2.4 h); and materials transport vehicles (N = 22, median measurement duration = 1.8 h). Whole-body vibration amplitudes either within or exceeding the ISO health guidance caution zone were consistently measured. In particular, shuttle cars demonstrated whole-body vibration amplitudes which frequently exceeded the health guidance caution zone. The potential effects of roadway maintenance, decreased vehicle speed, and shuttle car seat replacement were found to be practically meaningful.

Whole-Body Vibration Associated with Dozer Operation at an Australian Surface Coal Mine.

Bulldozers are used extensively on surface mine sites and have been previously identified as being associated with high amplitude whole-body vibration exposures. Previous investigations of this equipment have involved either a very small number of measurements, or measurements of very short duration (or both); or the data obtained were incompletely reported. This research reports 69 measurements (median duration 440 min) obtained from 15 different dozers during operation at a surface coal mine. More than one-third of vertical vibration measurements exceeded the ISO2631.1 Health Guidance Caution Zone when expressed as VDV(8). Considerable variability in measurement amplitudes was found. This was also true within measurements obtained from the same dozers on different shifts suggesting, by a process of elimination, that the remaining variability in whole-body vibration amplitude is a function of some combination of task characteristics, geology, and operator behaviour; rather than equipment-related variability, such as maintenance, suspension, seating, or track design. Short-comings in the evaluation methods provided by ISO2631.1 are highlighted.

Participatory ergonomics: Evidence and implementation lessons.

Participatory ergonomics programs have been proposed as the most effective means of eliminating, or redesigning, manual tasks with the aim of reducing the incidence of occupational musculoskeletal disorders. This review assesses the evidentiary basis for this claim; describes the range of approaches which have been taken under the banner of participatory ergonomics in diverse industries; and collates the lessons learned about the implementation of such programs.

Assessing colonoscopic inspection skill using a virtual withdrawal simulation: a preliminary validation of performance metrics.

BACKGROUND: The effectiveness of colonoscopy for diagnosing and preventing colon cancer is largely dependent on the ability of endoscopists to fully inspect the colonic mucosa, which they achieve primarily through skilled manipulation of the colonoscope during withdrawal. Performance assessment during live procedures is problematic. However, a virtual withdrawal simulation can help identify and parameterise actions linked to successful inspection, and offer standardised assessments for trainees. METHODS: Eleven experienced endoscopists and 18 endoscopy novices (medical students) completed a mucosal inspection task during three simulated colonoscopic withdrawals. The two groups were compared on 10 performance metrics to preliminarily assess the validity of these measures to describe inspection quality. Four metrics were related to aspects of polyp detection: percentage of polyp markers found; number of polyp markers found per minute; percentage of the mucosal surface illuminated by the colonoscope (≥0.5 s); and percentage of polyp markers illuminated (≥2.5 s) but not identified. A further six metrics described the movement of the colonoscope: withdrawal time; linear distance travelled by the colonoscope tip; total distance travelled by the colonoscope tip; and distance travelled by the colonoscope tip due to movement of the up/down angulation control, movement of the left/right angulation control, and axial shaft rotation. RESULTS: Statistically significant experienced-novice differences were found for 8 of the 10 performance metrics (p's < .005). Compared with novices, experienced endoscopists inspected more of the mucosa and detected more polyp markers, at a faster rate. Despite completing the withdrawals more quickly than the novices, the experienced endoscopists also moved the colonoscope more in terms of linear distance travelled and overall tip movement, with greater use of both the up/down angulation control and axial shaft rotation. However, the groups did not differ in the number of polyp markers visible on the monitor but not identified, or movement of the left/right angulation control. All metrics that yielded significant group differences had adequate to excellent internal consistency reliability (α = .79 to .90). CONCLUSIONS: These systematic differences confirm the potential of the simulated withdrawal task for evaluating inspection skills and strategies. It may be useful for training, and assessment of trainee competence.

A novel training device for tip control in colonoscopy: preliminary validation and efficacy as a training tool.

BACKGROUND: Effective control of the colonoscope tip is one of the most fundamental components of colonoscopy skill. Mastering fine tip control can be problematic for novice trainees, yet no validated training regimes exist for developing this specific skill component in isolation. We aimed to conduct a preliminary validation of a novel training device for colonoscopic tip control, and to assess its efficacy as a training tool. METHODS: In study 1 (validation), 13 experienced colonoscopists and 16 novices used a colonoscope to accurately track 28 targets on each of four concave "training surfaces" as quickly as possible, and we compared their performance. In study 2 (pre-post-training study), another 16 novices were tested before and after a six-session training program. In both studies, the main outcome measurements were completion time (measured automatically by the device) and variability of individual performance (the SD of each individual's completion times across trials). RESULTS: Compared with novices, experienced colonoscopists were faster (P < 0.0001) and their performances less variable (P < 0.0001). With training, novices became faster (P < 0.0001) and more consistent (P = 0.003), and these improvements also generalized to novel training surfaces (P's < 0.01). After training, the novices' tip control performance was indistinguishable from that of the experienced colonoscopists (P's > 0.05). The composite measures of completion time used in both studies all had acceptable to excellent internal consistency reliability (α's ranged from 0.72 to 0.93). CONCLUSIONS: We found that performance measures derived from using the device to assess skill can discriminate between experienced colonoscopists and novices in terms of their ability to control and guide the colonoscope tip precisely, providing preliminary evidence to support the construct validity of the metrics. The device is also an effective training tool for this fundamental component of colonoscopy skill.

Assessment of colorectal polyp recognition skill: development and validation of an objective test.

BACKGROUND: The quality of colonoscopy is known to vary. The extent to which colonoscopists can recognize the presence of subtle colorectal lesions by visually distinguishing them from the surrounding mucosa (i.e., polyp recognition skill) may be one of several attributes that influence polyp detection rates. The aim of the present study was to develop and validate the first objective test of polyp recognition skill. METHODS: Validation study. Twenty-eight experienced colonoscopists and eighty novices took a preliminary 280-item computer-based polyp recognition test. Items were genuine endoscopic images which participants assessed for the presence of "likely polyps." Half included clinically identified polyps. Participants clicked on a suspected lesion or a button marked "no likely polyp", and the main outcome measures were accuracy and response latency. The best items were selected for the final 50-item test. RESULTS: In the preliminary test, experienced colonoscopists correctly identified more polyps than novices (P < .0001) and better discriminated between clinically identified polyps and non-polyp features (as measured by d', P < .0001). For polyp items, the experienced group also responded faster (P < .01). Effect sizes were large for accuracy (Cohen's d = 3.22) and d' (Cohen's d = 3.22). The 50 final test items produced comparable results for accuracy, d', and response latency. For both versions of the test, score scale reliability was high for both polyp and non-polyp items (α = .82 to .97). CONCLUSIONS: The observed experienced-novice differences support the construct validity of the performance measures derived from the tests, indicating that polyp recognition skill can be quantified objectively. The final test may potentially be used to assess trainees, but test sensitivity may be insufficient to make fine-grained distinctions between different skill levels among experienced colonoscopists. More sensitive future tests may provide a valuable supplement to clinical detection rates, allowing objective comparisons between skilled colonoscopists.

The efficacy of training insertion skill on a physical model colonoscopy simulator.

Background and study aims: Prior research supports the validity of performance measures derived from the use of a physical model colonoscopy simulator - the Kyoto Kagaku Colonoscope Training Model (Kyoto Kagaku Co. Ltd., Kyoto, Japan) - for assessing insertion skill. However, its use as a training tool has received little research attention. We assessed the efficacy of a brief structured program to develop basic colonoscope insertion skill through unsupervised practice on the model. Participants and methods: This was a training study with pretesting and post-testing. Thirty-two colonoscopy novices completed an 11-hour training regime in which they practiced cases on the model in a colonoscopy simulation research laboratory. They also attempted a series of test cases before and after training. For each outcome measure (completion rates, time to cecum and peak force applied to the model), we compared trainees' post-test performance with the untrained novices and experienced colonoscopists from a previously-reported validation study. Results: Compared with untrained novices, trained novices had higher completion rates and shorter times to cecum overall (Ps < .001), but were out-performed by the experienced colono-scopists on these metrics (Ps < .001). Nevertheless, their performance was generally closer to that of the experienced group. Overall, trained novices did not differ from either experience-level comparison group in the peak forces they applied (P > .05). We also present the results broken down by case. Conclusions: The program can be used to teach trainees basic insertion skill in a more or less self-directed way. Individuals who have completed the program (or similar training on the model) are better prepared to progress to supervised live cases.

Long duration measurements of whole-body vibration exposures associated with surface coal mining equipment compared to previous short-duration measurements.

Previous measurements of whole-body vibration associated with earth-moving equipment at surface coal mines have highlighted the significance of the hazard. Considerable variability in measurement amplitudes, even within the same equipment type operated at the same site, has been noted. However, the measurements have previously been undertaken for relatively short durations. Fifty-nine measurements were collected from a range of earth-moving equipment in operation at a surface coal mine. Measurement durations ranged from 100-460 min (median = 340 min). The results indicate that the measurements previously observed are not an artifact of the relatively short durations and confirm that operators of dozers and off-road haul trucks, in particular, are frequently exposed to vertical whole-body vibration levels which lie within, or above, the Health Guidance Caution Zone defined by ISO2631.1. Further investigations are justified to identify opportunities for reducing operators' exposure to high amplitude vibrations.

A competency framework for colonoscopy training derived from cognitive task analysis techniques and expert review.

BACKGROUND: Colonoscopy is a difficult cognitive-perceptual-motor task. Designing an appropriate instructional program for such a task requires an understanding of the knowledge, skills and attitudes underpinning the competency required to perform the task. Cognitive task analysis techniques provide an empirical means of deriving this information. METHODS: Video recording and a think-aloud protocol were conducted while 20 experienced endoscopists performed colonoscopy procedures. "Cued-recall" interviews were also carried out post-procedure with nine of the endoscopists. Analysis of the resulting transcripts employed the constant comparative coding method within a grounded theory framework. The resulting draft competency framework was modified after review during semi-structured interviews conducted with six expert endoscopists. RESULTS: The proposed colonoscopy competency framework consists of twenty-seven skill, knowledge and attitude components, grouped into six categories (clinical knowledge; colonoscope handling; situation awareness; heuristics and strategies; clinical reasoning; and intra- and inter-personal). CONCLUSIONS: The colonoscopy competency framework provides a principled basis for the design of a training program, and for the design of formative assessment to gauge progress towards attaining the knowledge, skills and attitudes underpinning the achievement of colonoscopy competence.

Concurrent 3-D sonifications enable the head-up monitoring of two interrelated aircraft navigation instruments.

OBJECTIVE: The aim of this study was to enable the head-up monitoring of two interrelated aircraft navigation instruments by developing a 3-D auditory display that encodes this navigation information within two spatially discrete sonifications. BACKGROUND: Head-up monitoring of aircraft navigation information utilizing 3-D audio displays, particularly involving concurrently presented sonifications, requires additional research. METHOD: A flight simulator's head-down waypoint bearing and course deviation instrument readouts were conveyed to participants via a 3-D auditory display. Both readouts were separately represented by a colocated pair of continuous sounds, one fixed and the other varying in pitch, which together encoded the instrument value's deviation from the norm. Each sound pair's position in the listening space indicated the left/right parameter of its instrument's readout. Participants' accuracy in navigating a predetermined flight plan was evaluated while performing a head-up task involving the detection of visual flares in the out-of-cockpit scene. RESULTS: The auditory display significantly improved aircraft heading and course deviation accuracy, head-up time, and flare detections. Head tracking did not improve performance by providing participants with the ability to orient potentially conflicting sounds, suggesting that the use of integrated localizing cues was successful. Conclusion: A supplementary 3-D auditory display enabled effective head-up monitoring of interrelated navigation information normally attended to through a head-down display. APPLICATION: Pilots operating aircraft, such as helicopters and unmanned aerial vehicles, may benefit from a supplementary auditory display because they navigate in two dimensions while performing head-up, out-of-aircraft, visual tasks.

Control order and visuomotor strategy development for joystick-steered underground shuttle cars.

OBJECTIVE: In this simulator-based study, we aimed to quantify performance differences between joystick steering systems using first-order and second-order control, which are used in underground coal mining shuttle cars. In addition, we conducted an exploratory analysis of how users of the more difficult, second-order system changed their behavior over time. BACKGROUND: Evidence from the visuomotor control literature suggests that higher-order control devices are not intuitive, which could pose a significant risk to underground mine personnel, equipment, and infrastructure. METHOD: Thirty-six naive participants were randomly assigned to first- and second-order conditions and completed three experimental trials comprising sequences of 90 degrees turns in a virtual underground mine environment, with velocity held constant at 9 km/h(-1). Performance measures were lateral deviation, steering angle variability, high-frequency steering content, joystick activity, and cumulative time in collision with the virtual mine wall. RESULTS: The second-order control group exhibited significantly poorer performance for all outcome measures. In addition, a series of correlation analyses revealed that changes in strategy were evident in the second-order group but not the first-order group. CONCLUSION: Results were consistent with previous literature indicating poorer performance with higher-order control devices and caution against the adoption of the second-order joystick system for underground shuttle cars. APPLICATION: Low-cost, portable simulation platforms may provide an effective basis for operator training and recruitment.

Can an iPod Touch be used to assess whole-body vibration associated with mining equipment?

The cost and complexity of commercially available whole-body vibration measurement devices is a barrier to the systematic collection of the information required to manage this hazard. The potential for a consumer electronic device to be used to estimate whole-body vibration was assessed by collecting 58 simultaneous pairs of acceleration measurements in three dimensions from a fifth-generation iPod Touch and gold standard whole-body vibration measurement devices, while a range of heavy mining equipment was operated at three surface coal mines. The results suggest that accelerometer data gathered from a consumer electronic device are able to be used to measure whole-body vibration amplitude with 95% confidence of ±0.06 m s(-2) root mean square for the vertical direction (1.96 × standard deviation of the constant error).

Whole-body vibration exposure of haul truck drivers at a surface coal mine.

Haul truck drivers at surface mines are exposed to whole-body vibration for extended periods. Thirty-two whole-body vibration measurements were gathered from haul trucks under a range of normal operating conditions. Measurements taken from 30 of the 32 trucks fell within the health guidance caution zone defined by ISO2631-1 for an 8 h daily exposure suggesting, according to ISO2631-1, that "caution with respect to potential health risks is indicated". Maintained roadways were associated with substantially lower vibration amplitudes. Larger trucks were associated with lower vibration levels than small trucks. The descriptive nature of the research, and small sample size, prevents any strong conclusion regarding causal links. Further investigation of the variables associated with elevated vibration levels is justified. RELEVANCE TO INDUSTRY: The operators of mining equipment such as haul trucks are exposed to whole-body vibration amplitudes which have potential to lead to long term health effects. Systematic whole-body vibration measurements taken at frequent intervals are required to provide an understanding of the causes of elevated vibration levels and hence determine appropriate control measures.

Directional control-response compatibility relationships assessed by physical simulation of an underground bolting machine.

OBJECTIVE: The authors examine the pattern of direction errors made during the manipulation of a physical simulation of an underground coal mine bolting machine to assess the directional control-response compatibility relationships associated with the device and to compare these results to data obtained from a virtual simulation of a generic device. BACKGROUND: Directional errors during the manual control of underground coal roof bolting equipment are associated with serious injuries. Directional control-response relationships have previously been examined using a virtual simulation of a generic device; however, the applicability of these results to a specific physical device may be questioned. METHOD: Forty-eight participants randomly assigned to different directional control-response relationships manipulated horizontal or vertical control levers to move a simulated bolter arm in three directions (elevation, slew, and sump) as well as to cause a light to become illuminated and raise or lower a stabilizing jack. Directional errors were recorded during the completion of 240 trials by each participant RESULTS: Directional error rates are increased when the control and response are in opposite directions or if the direction of the control and response are perpendicular.The pattern of direction error rates was consistent with experiments obtained from a generic device in a virtual environment. CONCLUSION: Error rates are increased by incompatible directional control-response relationships. APPLICATION: Ensuring that the design of equipment controls maintains compatible directional control-response relationships has potential to reduce the errors made in high-risk situations, such as underground coal mining.

Using consumer electronic devices to estimate whole-body vibration exposure.

The cost and complexity of commercially available devices for measuring whole-body vibration is a barrier to the systematic collection of the information required to manage this hazard at workplaces. The potential for a consumer electronic device to be used to estimate whole-body vibration was assessed by use of an accelerometer calibrator, and by collecting 42 simultaneous pairs of measurements from a fifth-generation iPod Touch and one of two gold standard vibration measurement devices (Svantech SV111 [Svantech, Warsaw, Poland] or Brüel & Kjær 4447 [Brüel & Kjær Sound & Vibration Measurement A/S, Nærum, Denmark]) while driving light vehicles on a variety of different roadway surfaces. While sampling rate limitations make the accelerometer data collected from the iPod Touch unsuitable for frequency analysis, the vibration amplitudes recorded are sufficiently accurate (errors less than 0.1 m/s(2)) to assist workplaces manage whole-body vibration exposures.

Personal consequences of work-related physical discomfort: an exploratory study.

BACKGROUND: Work-related physical discomfort has been reported in Australian optometrists. The purpose of this paper is to explore the personal consequences of work-related discomfort. METHODS: Forty-seven optometrists with self-reported work-related discomfort participated in a 30-minute telephone or face-to-face interview related to ergonomics and physical comfort. Self-employed, employee, locum and retired optometrists participated. Four avenues were investigated; namely, description of discomfort, non-work contributing factors, whether the participant has ever stopped work due to discomfort, and the treatments accessed to alleviate discomfort. These data were subject to qualitative and quantitative analyses. RESULTS: Reported discomfort ranged from mild to severe. Eight participants (17 per cent) ascribed their discomfort entirely to work and seven (15 per cent) cited non-work factors as the cause. Many participants (32, 68 per cent) reported that non-work factors, for example, sport and driving, aggravated existing work-related discomfort and for some, their discomfort impacted on home and leisure activities. There were 15 participants (32 per cent), who have stopped work because of discomfort, including two who have ceased working as an optometrist and two who now work reduced hours. The majority (32) continue to work despite discomfort. Many participants (31, 66 per cent) seek treatment to alleviate discomfort, with seven participants (15 per cent) reporting that they receive multiple therapies per week. Work-related discomfort was generally viewed as a personal issue, with most participants accessing treatment in their own time (27, 57 per cent) and funding it personally or with private health insurance. Only four participants have received funding through workers' compensation or income protection insurance. CONCLUSIONS: Work-related discomfort has significant financial and personal costs for some Australian optometrists. These qualitative data can be used to develop quantitative tools for assessing the impact of discomfort on quality of life for optometrists and their families. The results also highlight the need for preventative action to reduce work-related discomfort within the optometric profession.

A new pre-employment functional capacity evaluation predicts longer-term risk of musculoskeletal injury in healthy workers: a prospective cohort study.

STUDY DESIGN: Prospective cohort study. OBJECTIVE: To determine if a job-specific pre-employment functional assessment (PEFA) predicts musculoskeletal injury risk in healthy mineworkers. SUMMARY OF BACKGROUND DATA: Traditional methods of pre-employment screening, including radiography and medical screenings, are not valid predictors of occupational musculoskeletal injury risk. Short-form job-specific functional capacity evaluations are increasing in popularity, despite limited evidence of their ability to predict injury risk in healthy workers. METHODS: Participants were recruited from an Australian coal mine between 2002 and 2009 as part of the hiring process. At baseline, participants were screened with the JobFit System PEFA, and classified as PEFA 1 if they met job demands and PEFA>1, if not. Males who completed the PEFA and were employed were included. Injury data from company records were coded for body part, mechanism, and severity. The relationship between PEFA classification and time to first injury was analyzed using Cox proportional hazards regression with adjustments for department and post hoc stratification for time (0-1.3 yr, 1.3-6 yr). RESULTS: Of the 600 participants (median age, 37 yr, range, 17.0-62.6 yr), 427 scored PEFA 1. One hundred ninety-six sprain/strain injuries were reported by 121 workers, including 35 back injuries from manual handling. Significant differences between PEFA groups were found in time to first injury for all injury types during the long term (any injury: adjusted hazard ratio [HR] = 2.3, 95% confidence interval [CI] = 1.4-3.9; manual handling injury: HR = 3.3, CI = 1.6-7.2; any back injury: HR = 3.3, CI = 1.6-6.6; back injuries from manual handling HR = 5.8, CI = 2.0-16.7), but not during the short term. An area under the receiver operator curve value of 0.73 (CI = 0.61-0.86) demonstrated acceptable predictive ability for back injuries from manual handling during the long term. CONCLUSION: JobFit System PEFAs predict musculoskeletal injury risk in healthy mineworkers after 1.3 years of employment. Future research should assess whether use of these assessments as part of a holistic risk management program can decrease workplace musculoskeletal injuries.

The perceived importance and the presence of creative potential in the health professional's work environment.

The value of creative employees to an organisation's growth and innovative development, productivity, quality and sustainability is well established. This study examined the perceived relationship between creativity and work environment factors of 361 practicing health professionals, and whether these factors were present (realised) in their work environment. Job design (challenges, team work, task rotation, autonomy) and leadership (coaching supervisor, time for thinking, creative goals, recognition and incentives for creative ideas and results) were perceived as the most important factors for stimulating creativity. There was room for improvement of these in the work environment. Many aspects of the physical work environment were less important. Public health sector employers and organisations should adopt sustainable strategies which target the important work environment factors to support employee creativity and so enhance service quality, productivity, performance and growth. Implications of the results for ergonomists and workplace managers are discussed with a participatory ergonomics approach recommended. PRACTITIONER SUMMARY: Creative employees are important to an organisation's innovation, productivity and sustainability. The survey identified health professionals perceive a need to improve job design and leadership factors at work to enhance and support employee creativity. There are implications for organisations and ergonomists to investigate the creative potential of work environments.

Visual feedback system to reduce errors while operating roof bolting machines.

PROBLEM: Operators of roof bolting machines in underground coal mines do so in confined spaces and in very close proximity to the moving equipment. Errors in the operation of these machines can have serious consequences, and the design of the equipment interface has a critical role in reducing the probability of such errors. METHODS: An experiment was conducted to explore coding and directional compatibility on actual roof bolting equipment and to determine the feasibility of a visual feedback system to alert operators of critical movements and to also alert other workers in close proximity to the equipment to the pending movement of the machine. The quantitative results of the study confirmed the potential for both selection errors and direction errors to be made, particularly during training. RESULTS: Subjective data confirmed a potential benefit of providing visual feedback of the intended operations and movements of the equipment. IMPACT: This research may influence the design of these and other similar control systems to provide evidence for the use of warning systems to improve operator situational awareness.