Finding technology solutions to combat operator fatigue
Around-the-clock operations are commonplace in the mining industry. The search is on to help those who experience the fatigue that goes along with shift-work. Operator fatigue is proven to be one of the most prevalent causes of accidents within the mining industry. In the surface mining industry alone, some 60 to 65 percent of truck haulage accidents are directly related to operator fatigue.
Mining companies have long been aware of the dangers of fatigue and have tried to manage the situation through policies and procedures, and through various education, training, scheduling, diet and motivational efforts.
“These techniques all help deal with the root causes of fatigue,” says David Edwards, Ph.D., an ergonomics research engineer who studied operator fatigue in Caterpillar Inc.’s Technology and Solutions Division before joining the new Caterpillar Safety Services Division.
“At the end of the day, there are still people falling asleep,” says Edwards. “That’s why everyone in the industry is desperate for a new solution — a technology solution — to help better manage fatigue.”
The cost of fatigue
Sleep deprivation, fatigue and drowsiness decrease awareness, diminish attention spans, and increase reaction time — all significant factors that contribute to accidents. The UK reports over US$2 billion in fatigue-related accident costs. Australia’s Transport Safety Bureau reports that 30 percent of all fatal crashes are linked to fatigue. Commercial on-highway truck collisions due to fatigue are estimated to account for 1,200 deaths and 76,000 injuries a year in the United States, at an estimated cost of US$12.4 billion to the commercial trucking industry.
Fatigued drivers often are not aware of their condition, frequently driving for up to 30 seconds with their eyes totally closed — a situation known as micro-sleeps. Studies show that driving drowsy is equivalent to being under the influence of alcohol or drugs and that drowsiness impairs the ability to make decisions. Signs of fatigue include:
- Sleepiness/difficulty keeping eyes open
- Excessive yawning
- Blurred vision/loss of focus
- Becoming quiet and more withdrawn
- Inability to concentrate
- Inability to remember activities of the last five minutes
- Lacking motivation to do the task well
Studies in the mining industry indicate that fatigue affects even those with the best training and years of experience. Human error due to fatigue is not fundamentally a behavioral problem — it’s primarily a problem of human physiology.
Managing the situation
Ergonomic improvements in the operator environment have helped lessen fatigue. Education, training and biocompatible scheduling have also proven to be important tools.
“Miners can learn the importance of a good diet — what foods to eat to keep them alert and help them maintain energy levels,” says Bill Sirois, senior vice president of Circadian Technologies, Inc., a leading international research and consulting firm that assists shift-working companies. “Workers also can learn the right behaviors at work and at home that help minimize drowsiness.”
A lot of sites have started educating the families of employees about how to best support their family members for shift-work. More and more companies are also converting to user-friendly work schedules to alleviate as much of the physical stress of shift-work as possible, Sirois says.
In conjunction with Circadian Technologies Inc., Caterpillar will introduce a CD/DVD designed to educate supervisors, operators and their families on things they can do to lessen fatigue. “Caterpillar used its resources to create an educational tool that we can share with every mine site,” says Edwards.
While an educational video will be helpful, Caterpillar customers have made it clear that they’re looking for additional solutions — in particular those that take advantage of technology to detect the onset of fatigue and interface with the operator and dispatcher to elicit a response.
“There has been a major effort to develop technologies to monitor fatigue, but they have been primarily for automotive use — particularly with on-highway trucks,” says Edwards. “There isn’t one technology that has come to the forefront for use in the mining industry.”
Caterpillar and mining companies have tried to leverage existing automotive technologies to adapt them for mining, but have met with little success.
“We started thinking we would have more success if we can get to the source and get them interested in mining,” Edwards says. “Then we could develop a technology that is focused on mining from the beginning.”
Caterpillar is providing funds and access to mining equipment that allows research and development groups to work on a fatigue management solution for the industry.
“We want these researchers to see the differences between on-highway trucks and large mining trucks and their environments,” Edwards says. “We need to increase awareness in the scientific community that there is a need for them to provide solutions to help miners and mining companies mitigate the effects of fatigue.”
Advancing existing technologies
Caterpillar recently partnered with customer BHP Billiton to study existing technologies and promote the advancement of the most promising solutions. Results of that study will be published and shared with the world to advance the cause, says Edwards.
“Along with Circadian Technologies, we evaluated all known technologies that are commercially available or will be emerging in the next three years,” Edwards says.
The goal of the study was to:
- Identify the most promising technologies
- Develop an objective assessment tool
- Score each technology
- Examine the feasibility of incorporating the best technologies into mining applications
“We came up with a list of 35 technologies in all industries, and shortened that list to the 21 we felt were the most viable,” Edwards says. “We then tested the leading technologies through driving simulation studies and field trials.”
Two main types of technology exist: “fitness for duty” tests that check operator fatigue levels prior to their shifts, and systems that measure operator and machine behavior during operations. These technologies measure:
- Machine behavior
- Lane deviation
- Steering wheel movement
- Pedal usage
- Machine movement
- Operator physiological conditions
- Eye behavior (blink and pupil response properties)
- Heart rate
- Operator behavior
- Head nodding
- Mental and physical reaction times
Fitness-for-duty tests have been in use for some time to check operators for drug and alcohol usage. New technologies are being employed to test for fatigue, including:
- Pupilometry — measures eye reflexes, pupil constriction and the speed of eye movement. Degradation of reaction times can indicate impairment.
- Psychomotor Vigilance Tests — evaluate reaction times and hand/eye coordination. Using a computer mouse, trackball or joystick, operators must follow a target and maintain their position.
“These units are not cost-prohibitive,” says Edwards. “They range from US$5,000 to US$10,000 per unit and they are rock solid for drugs and alcohol. We’re still evaluating how well they work for fatigue, or more precisely, impaired alertness.”
Systems that monitor operator activity in the cab as well as vehicle activity also show promise. These systems monitor the operators around the clock, sometimes sending information to dispatchers as well as accumulating long-term data about the behavior of an operator or his or her machine.
On-board technologies include:
- In-dash cameras or eyeglasses with sensors that monitor eye movement and blink speeds — both indicators of fatigue. In-dash systems can have difficulty with vibration or motion in the cab, making the glasses a more viable option, Edwards says. The eyeglass system, called Optalert™ and made by Sleep Diagnostics Pty Ltd., costs about US$10,500 per truck. The price includes three pairs of glasses and system hardware.
- Monitors that measure steering wheel and machine movement. When operators are awake and alert, they maintain consistent position within their lane. When they get drowsy, movements are more erratic and machines swerve and sway. The leading system of this type is ASTiD made by Pernix Ltd. and costs less than US$10,000 per truck. Unlike the eyeglasses, this system is passive to the operators.
One of the technology systems investigated helps mine sites manage the information gained through monitoring — a feature Edwards can see as the future of fatigue management technologies. Data goes to a dispatcher, who has a log of the operator’s habits and can suggest a break or recommend the operator end his shift.
Edwards says it’s important to make someone other than the operator aware of any fatigue issues. “An operator who is fatigued is the worst judge of how tired he really is,” he says. “That’s like asking a drunk person if they believe they are too intoxicated to drive.”
Studies suggest that users strongly prefer systems that require as little personal monitoring and contact with the technology as possible. The preference is for systems that monitor vehicles instead of people.
“There are a lot of confidentiality issues, in particular with the operator measurements,” says Edwards. “The operator could have a perception that being personally monitored is a bad thing — so they may choose not to use a given technology.”
“Good technologies exist and we think they are viable,” says Edwards. “The question is, ‘How do you create a technology that deals with the world, and works for all?’ The answer is, ‘You can’t.’ We know we must have multiple solutions because all current technologies exhibit shortcomings when the application range is too broad. In other words, they don’t work everyone in every situation.”
“There are some things you cannot change,” he continues. “You will always have people falling asleep no matter what you do. People are simply not designed to be awake at night. No matter how much you do, you can’t prevent it from happening. The best thing you can hope for is to manage and mitigate the risk.” His recommendation is to use a combination of technologies.
“The Optalert glasses and ASTiD steering system performed best in the lab testing. The ideal solution in the long term would be to fuse these types of technologies together. A system that combines information from both the machine and the operator is the best hope for robustly detecting fatigue and drowsiness in the future. That’s what we’re recommending to the developers.”
Cat will continue to provide support for research and development and allow access to Cat machines for companies to test their products.
“They are the experts,” Edwards says. “We’re not in a position to put this equipment on a machine at the factory. The technology is too immature at this point. But we can try to influence developers to move quickly.”
The most important aspect of a successful fatigue management program is taking responsibility. “We must ensure that people recognize and take responsibility for their own fitness for work,” says Michael Farmer, global practice leader for fatigue management at BHP Billiton. “Frontline supervisors must understand and manage their workgroups, and companies must develop a culture that encourages workers to report and take action on drowsiness and fatigue risks.”
Edwards says he is proud of Caterpillar’s focus on this important topic. “We’re working to meet the mining industry’s needs, the customer’s needs and to energize the research community to care,” he says. “We’ll share this with the world and hopefully all companies can benefit. And we can make the world a safer place to live and work.”
Managing a mining lifestyle
One out of five people in the world currently works hours that fall outside the traditional workday. Those who have long hours, work nights, or maintain irregular shifts face different challenges than day workers. Shift work affects sleep, alertness, health, and family and social lives.
Human alertness has a daily rhythm — measurably higher during the day and lower during the night. People also tend to get drowsy after lunch. It’s important to be aware of and manage these challenges.
Caterpillar is collaborating with Circadian Technologies, Inc., an international firm that helps companies manage shift-work and extended hours, to develop a DVD to help machine operators and their families better cope with the lifestyle required of those in the mining industry.
The video provides practical solutions for easing the adjustment and day-to-day challenges associated with mining lifestyles. The video serves as a powerful tool for improving the physical and psychological well-being of heavy equipment operators — increasing safety, morale and performance.
How to get better sleep
Manage your environment
- Make the environment as dark as possible or wear eye shades because even low levels of light can keep people awake or disrupt sleep.
- Use a fan, air filter or other white noise machine to block outside noises, or wear earplugs.
- Keep the environment at a cool temperature and well ventilated.
Manage your diet
- Be aware that while alcohol may cause drowsiness, it can make sleep less restful and restorative.
- Avoid heavy caffeine use, which can cause less or poor quality sleep.
- Consult a doctor before using sleeping pills; they are not a long-term solution.
- Try warm milk, decaffeinated herbal teas or herbs like valerian and kava to induce sleep.
Manage your routine
- Stick to the same routine whether you sleep at night or during the day.
Manage your health
- When eating late at night, avoid fatty and fried foods, pastries and dairy products to alleviate gastrointestinal problems.
- Eat small meals through the night shift, including pasta, breads, fruits, vegetables and low-fat dips and spreads.
- Eat lean protein and complex carbohydrates for your main meals to increase energy levels.
- Elevate your heart rate for 20 to 30 minutes several times a week.
- Try to identify and eliminate the causes of stress.
- Learn to control what you can and stop worrying about things that are beyond your control.
- Take time for yourself.
- Spend time with family and friends.
- Slow down and eliminate extra activities if you can.
- Avoid excessive amounts of toxins and stimulants.
Manage your home life
- Identify and resolve family and social problems when they arise.
- Talk with your family regularly to discuss problems, resolve issues and plan activities.
- Keep a calendar and plan ahead as much as possible.
- Map out “recovery days” to allow you to catch up on sleep and get back into a regular daytime lifestyle.
How to prepare for shift work
- Prepare for night shifts by going to bed later at night and sleeping later in the morning on days off.
- Wear dark sunglasses on the way home from work if it is daylight.
- Go to bed as soon as possible after a night shift.
- Eat a light breakfast before sleeping to prevent waking due to hunger.
- Sleep five hours after the shift, then take a nap just before going to work.
- Avoid caffeinated beverages for the last three to four hours of your shift.