In this blog we’ll be looking at the impacts of fatigue in heavy industry, and specifically mining. To learn more about the topic of how to mitigate fatigue in heavy industries, sign up for our on-demand webinar on that topic HERE.
Across heavy industry, awareness of the dangers of fatigue is growing. In industries such as construction, commercial trucking, and mining, fatigue has been found to be the single greatest cause of accidents. We’ll be looking specifically at how the mining industry is affected by fatigue, and what steps the industry can take.
The “fatigue” that has contributed to accidents in the mining industry refers to cognitive fatigue,rather than the physical fatigue associated with feeling tired after demanding physical work. Cognitive fatigue is typically caused by either a lack of sleep or wakefulness outside of normal daylight hours. This kind of mental fatigue inhibits the brain’s ability to interact with the body. As one might imagine, a
body without a brain in control is a dangerous thing. The effect of fatigue in these instances is comparable to impairment from alcohol.
One doesn’t need to look far for examples of the dangers of fatigue in the workplace. Three of the largest industrial accidents in modern history were all impacted by fatigue. The Chernobyl power plant accident, the Exxon Valdez oil tanker spill, and the BP Texas City refinery are all known to have fatigue as a contributing factor.
In industries that include transportation, mining, construction, and oil and gas, it’s common for the 24/7 nature of operations to invite fatigue in the workplace. In many of these industries, the required schedules produce conditions where fatigue within the workplace is unavoidable. Following the Croydon tram derailment in the UK, one of the drivers involved commented the following:
“No one is ever fully awake. I was always in a bit of a daze and that is because the way the shift work doesn’t allow the drivers to get a regular sleep pattern.”
– Former Tram Driver, Croydon Tram Derailment, 9 November 2016
Besides the effect on cognitive and motor skills, fatigue also plays upon an individual’s emotional wellbeing. Some might assume that only irritability and moodiness result from fatigue, but the repercussions of fatigue reach beyond observable behaviour. When fatigue is present, there is a measurable increase to levels of anxiety, frustration, and impulsivity. These will impact the wellbeing of employees and those around them.
In positions that require focused communications or attention to detail, fatigue can have severe consequences. Workers can expect to see the following abilities impacted when suffering from fatigue:
- The ability to recall specific events or operating procedures
- Decision making
- Emotional stability
In a dangerous work environment, a lapse in any one of these essential functions could mean disaster.
Looking at risk factors affecting mining operations, one doesn’t need to look far to see that fatigued employees needs to be taken seriously. The body of evidence around the risk posed by fatigue in mining has been growing steadily for years, as has the obligation of employers to their employees’ safety.
The earliest study we’ll be looking at dates back to 1996 and was undertaken by the U.S. Bureau of Mines in order to improve haulage truck safety. This study’s finding was that “‘perceptual-cognitive-motor’ errors (related to the more common term, “human error”) were a causal factor in 93% of the accidents.” While no conclusive human factors were isolated in the 1996 report, the findings noted that future “investigations of the psychological and physiological factors of reducing operator-induced accidents” would be necessary.
Fatigue-related safety events have adverse consequences for the individual, but can also impact on co-workers, the organisation for which he or she works, and even the broader community
London Department for Transport
Since the initial studies that attempted to pinpoint a cause of significant injuries in heavy industry, a more complete understanding of the impact of worker wellbeing has developed. Fatigue management systems are now often implemented within mining operations. Looking at the effects of a Fatigue Management System, a 2014 article in the journal Minerals Engineering looked at a case study in small mining operations. Beyond the impacts of fatigue on safety within the mines, the article also looked at the impacts of fatigue upon the health and wellbeing of operators, extending into the surrounding community.
The study showed that although there were costs incurred by implementing a fatigue risk management system, adjusting the work schedule likely improved the quality of work and home life for employees. The conclusions of the paper focused largely on the need for workplace-specific solutions to resolve fatigue-related issues facing workers.
Within the mining industry, there are several specific ways that fatigue and disruption of sleep can impact workers and operations. It’s been estimated that as many as 65% of truck-driving accidents in open pit mines are fatigue-related. This can likely be accounted for by the impact of sleep on motor skills and cognitive abilities that include problem solving and short-term memory. Workers who find themselves fatigued are not only more likely to make physical mistakes while completing their work, but they’re more likely to make errors in judgement.
Underground miners are placed in an especially difficult situation from fatigue risks. In the article Mine Worker Fatigue and Circadian Rhythms, Max Martell looks at a number of ways that mining safety is impacted by fatigue and disruptions to natural sleep habits. Martell finds that not only are underground miners at risk of the same kinds of fatigue-induced accidents as above-ground mining, but they are also at risk of disrupted circadian rhythms during the day. A combination of overnight work schedules and days spent underground with artificial light sources can further disrupt sleep patterns. Further compounding the problem are the non-reflective environments in mines and reduced eyesight in an aging mining workforce which both contribute to receiving reduced light exposure while underground.
Looking at the wider-reaching effects of fatigue, we see that fatigue has a direct impact on reaction times, meaning the ability to observe something and then respond to it. In tasks such as driving, which can require split-second decisions from the driver in order to avoid accidents, even a very short delay in reaction can be disastrous to the driver, their passengers, and others nearby.
Fatigue also increases the likelihood of micro-sleeps, which we typically associate with a “lapse” where someone enters a state of sleep for a short period of one or more seconds before regaining consciousness. During these periods, an individual is not reactive at all, and an immediate danger can easily be missed.
Using research completed by the US Army, we know that sleep is impacted by a variety of factors, including the amount that you sleep, the quantity of sleep, and the quality of your sleep. Let’s break down what each of these factors really means:
Quality: Interruptions during sleep can have an impact on its restorative nature.
Consistency: Keeping a regular sleep and wake schedule is important for receiving the maximum benefits of sleep. This means that going to bed and
waking up at different times can have a negative impact on sleep.
Time of day: Even good sleep habits can be negated by sleep that is happening at the “wrong” time of day.
With all 3 of these factors, we see immediate implications for shift workers and those working overnight. Consistent sleep habits are incredibly important, as poor sleep from a week ago or longer can still impact an individual’s fatigue level. This is especially true in situations where that individual has had a continuous stretch of poor sleep. This means that it’s best to think about sleep cumulatively, and to consider sleep habits over the course of at least one week when studying fatigue levels.
Considering the role that consistency plays in the restfulness of sleep, we see that mitigating the risks of fatigue means much more than simply achieving a single night of restful sleep. In order to fully tackle fatigue management, it means:
- Adopting more consistent sleep habits that encourage regular sleep and wake times
- Sleeping for longer durations without interruptions
- Trying whenever possible to sleep at nighttime.
All these factors can give us a picture of someone achieving 7 or more hours of uninterrupted sleep each night and sleeping and waking within the same 30-minute window every day. Because the ideal sleep schedule that we’ve described isn’t always possible, that raises the question of how we can predict fatigue among individuals who aren’t able to keep this kind of consistent sleep schedule, such as industrial and mining workers.
Among industrial workforces, shifting start times are likely to affect sleep and wake times. In the event that these workers are sleeping during the day, their quality of sleep and likelihood of awakening during a sleep period are also going to be heavily impacted. A period of awakening won’t always be remembered by someone, but it represents a period where sleep has been disrupted even if the individual was not consciously awake.
After conducting their own research, the US Army developed a model which allows for prediction of fatigue levels for the day ahead based on the sleep data of the previous week. This model, known as the SAFTE™ Alertness Model, takes into account all of the previous factors we’ve looked at (consistency, quantity, quality of sleep), and produces a score which indicates an individual’s alertness.
The score itself ranges from 0 to 100, and individuals typically fall somewhere between 60 and 100 on the scale. The higher an individual’s score is, the more alert they are likely to be, which has an immediate implication within the modern industrial workplace. Reaction times can be directly plotted along the SAFTE™ Alertness Model to indicate how quickly you can expect an individual to respond.
Using a familiar comparison, a score of 70 on the SAFTE™ Alertness Scale corresponds to the same reaction time that we could expect from an individual with a blood alcohol level equivalent to 0.08. An individual at this level would have a reaction time up to 43% longer than someone who is fully rested.
Using the example of mining workers driving vehicles or operating heavy equipment, the need to mitigate the risks of fatigue in the workplace become more apparent. An individual suffering from heavy fatigue in these situations is a danger to not just themselves, but their colleagues as well.
While developed by the US Army, this model has been validated in independent studies. These studies have shown a direct relationship between an individual’s score on the scale, and the likelihood and severity of an accident in the workplace. A study conducted by the US Department of Transportation within the railroad industry showed that the cost of accidents caused by those falling below 70 on the alertness scale were up to five times more costly than those caused by individuals above 90 on the scale.
The SAFTE™ Alertness Model continues to be used by the Federal Aviation Administration in the US Department of Transportation and in the US Air Force.
The Readiband™ is a tool developed by Fatigue Science that is designed to help workers and organizations take advantage of the SAFTE™ Alertness Model to predict and mitigate the risks of fatigue. This is a wearable device with a long battery life which serves the purpose of capturing high quality sleep data. The Readiband™ is worn at night to capture sleep data and can otherwise be worn during the day to check the time. GPS data and other biometrics are not captured in order to preserve the privacy of the individual. The predictive nature of the SAFTE™ model means that workers can use the insights gained from the Readiband™ to both predict their fatigue levels and to build better sleep habits by maintaining regular sleep times.
- Analysis of Occupational Accidents in Underground and Surface Mining in Spain Using Data-Mining Techniques
International Journal of Environmental Research and Public Health, Sanmiquel, et al. (2018)
- Mine Worker Fatigue and Circadian Rhythms
Engineering and Mining Journal, Max Martell (2018)
- Managing fatigue in mining
Australian Mining (2018)
- Fatigue Risk Management Systems: A Review of the Literature
London Department for Transport
- Fatigue Management in Mining – Time to Wake Up and Act
- Application of fatigue management systems: small mines and low technology solutions.
Mining Engineering, Eiter BM, et al. (2014)
- Haulage Truck Dup Site Safety: An Examination of Reported Injuries
U.S. Department of Health and Human Services, FC Turin, et al. (2001)
- Safety Analysis of Surface Haulage Accidents
Proc 27th Annual Institute on Mining Health, Safety and Research, RF Randolph et al. (1996)
- A well structured safety management system
Canadian Mining (2015)