For workers whose schedules run through the night, an energy economy also has a daily rhythm: time on the job, time to travel home and time to sleep. Campbell County’s historical employment and training figures provide a starting point for understanding shift work and fatigue.
An economy that ran in shifts
In the Data Center’s 2006 table, mining was the largest employment line, with average employment of 6,938 out of a county total of 20,793. In 2008, CCEDC described Gillette as the “Energy Capital of the Nation,” pointing to oil, natural gas, power plants and coal mines. By 2014, the Technology Center offered diesel, welding, electrical, safety, engineering, mining, power and culinary training.
Those dated descriptions place industrial work within the county’s economic story. A 2022 overview in the American Journal of Industrial Medicine, involving researchers from the National Institute for Occupational Safety and Health (NIOSH), describes mining as an important shift-work industry for United States commerce. The Occupational Safety and Health Administration (OSHA) also identifies oil field and construction workers among groups commonly working irregular or extended shifts. These sources provide context for thinking about work schedules without establishing the hours of any particular Campbell County workplace.
The body’s 24-hour clock
The American Academy of Sleep Medicine’s shift-work explanation describes circadian rhythms as the body’s internal clock, signaling when it is time to feel sleepy or alert. That clock operates on a roughly 24-hour schedule. A work roster and the body’s preferred sleep time can therefore pull in different directions: work may fall when the body expects sleep, while the available sleeping period falls when it expects wakefulness.
The Academy identifies early-morning, night, overnight and rotating shifts as schedules that can present difficulties. Many people initially find a change of shift hard to adjust to. For someone moving between daytime and nighttime work, the relevant question is more than the number of hours away from the job. It is also when those hours occur and whether they include a period of sleep.
What fatigue does on the job
In its guidance on fatigue hazards, OSHA describes fatigue as a signal that rest is needed. Too little sleep, interrupted sleep or poor-quality sleep over time can contribute. OSHA lists sleepiness, weariness, irritability, reduced alertness, impaired decision making and difficulties with concentration and memory. In a working day, those concerns belong alongside the task and the conditions in which it is performed.
OSHA reports accident and injury rates 18 percent higher on evening shifts and 30 percent higher on night shifts than on day shifts. It also reports an association between working 12 hours per day and a 37 percent increase in injury risk. These are general figures reported by OSHA, not measurements of Campbell County workers or predictions for an individual shift.
The 2022 mining overview adds circumstances particular to mine work: monotonous or disengaging tasks, underground environments and light exposure, and remote operations. It calls fatigue a continuing challenge and describes research on mineworker fatigue as limited. The schedule is one part of that picture; the work setting also matters.
What studies of miners have observed
A 2020 study in the Journal of Occupational and Environmental Medicine followed 70 underground miners through 14 consecutive 12-hour day and/or night shifts. They wore a device that recorded activity and rated their vigilance four times per shift. The researchers compared sleep and alertness across the extended sequence of workdays.
Recorded sleep duration did not differ significantly between day and night shifts: the reported values were six hours 34 minutes and six hours 44 minutes. Yet vigilance at 5:30 a.m. remained significantly lower than at the beginning of the night shift throughout all 14 night shifts. The study described limited adjustment of the body clock in terms of nighttime vigilance, despite good sleep quality.
The finding draws attention to the distinction between sleep duration and alertness at a particular hour. Similar amounts of sleep did not mean similar vigilance throughout the night. The participants were underground miners; the study does not establish conditions at local mines or a timetable on which every worker adjusts.
Schedules and rotation: what the evidence says
A 2023 review in the Cochrane Database of Systematic Reviews examined 11 studies with 2,125 participants. It considered changes to shift schedules and their relationship to sleep quality, sleep duration and sleepiness. The studies differed in the changes they examined and the ways they measured results.
Forward and faster rotation may reduce sleepiness during shifts, the review reported, but the evidence was very uncertain. Very low-certainty evidence also suggested less sleep between shifts with faster rotation. In studies of workweeks with a 16-hour shift limit, evidence for increased sleep duration was of low certainty. That comparison is a research finding, not a recommended shift length. The review called for more high-quality studies before firm conclusions could be drawn.
The American Academy of Sleep Medicine suggests clockwise rotation, meaning each successive shift begins later than the preceding one. Its explanation is that staying up later is easier than going to bed earlier. This practical suggestion should be read alongside Cochrane’s uncertainty about the effects of schedule changes.
Sleep and rest between shifts
OSHA’s fatigue-prevention guidance includes responsibilities for employers as well as everyday sleep suggestions for workers. Employers can examine workload and staffing, arrange frequent opportunities for rest breaks and nighttime sleep, and consider workplace lighting, temperature and surroundings. This places rest within the organization of work, alongside the worker’s time at home.
For workers, OSHA suggests a daily sleep period of seven to nine hours without disruptions and sleeping at the same time each day. It describes a comfortable, cool, dark and quiet sleeping environment. For evening or night work, it suggests that sleep should have occurred within the eight hours before going to work.
The Academy’s sleep tips for shift workers suggest a 20- to 30-minute nap before a night shift or during a break, where possible. They also suggest keeping the same schedule on workdays and days off, and beginning to move sleep time a few days before a major schedule change.
For the journey home after night work, the Academy suggests arranging a ride or using a bus or cab, citing the risks of drowsy driving. Before daytime sleep, it advises avoiding morning sunlight, wearing sunglasses when outside, and asking others in the household to keep the home quiet. These suggestions address the hours surrounding a shift as well as the shift itself.
OSHA’s guidance ends with a simple step for difficulty sleeping: keeping a sleep diary and discussing the difficulty with a doctor.