Fatigue Study: Understanding the effects of fatigue in a mining environment
Back in 2015, Dr. Arash Shahi from the University of Toronto conducted a study of mining industry work cycles, employee experience and shift duration. The goal was to identify trends that those in the industry could learn from, and in turn reduce our accident rates.
The first area of analysis focused on work cycles to see if safety incidents were occurring more frequently in work cycles with a higher number of shifts. We looked at three types of work cycles: 5/2, 14/2 with a long change (L/C) at 7 days and 28/7 with a L/C at 14 days. The study looked at the incident data to understand if there were incident patterns in the work cycle. The research identified that accidents were more preventable and occurred more frequently during the end of the cycle. For example, on a 5/2 cycle we found between 40% - 58% of accidents were occurring on the last day prior to the two days off. On the 14/2 work cycle, it was observed that a 58% increase in accidents occurred just prior to the L/C. On the 28/7 work cycle, we saw that 31% of accidents occurred on the last day of the 4th week of the work cycle.
Work Cycle Table: Long change (L/C) is a day where a worker goes from day shift to night shift. No work occurs for a 24hour period. All shifts are 12 hours in duration.
The second area of focus was the correlation between work experience and accident frequency. It was found that employees who had been working for the organization less than 12 months accounted for 76% of all incidents. We did look further into the reason this was occurring and conducted another study that focused on 12 altitudinal criterion to help understand the reason; we will share the results of that study in another article.
We also looked at time of the shift (day or night), and most accidents were occurring on day shifts. The data consistently showed that nearly three quarters of the accidents were occurring on day shifts.
We looked closely at breaks during these shifts and found that on average, workers took 2-3 breaks longer than 5 minutes during their shift, which included their lunch break. Thirty per cent of workers consumed energy drinks. Sleep durations did vary depending on where the worker slept, i.e. camp versus home (6.4 hours and 7.6 respectively).
In 2016, we presented our findings at the WSN conference; the presentation slides are available here: https://www.workplacesafetynorth.ca/resources/impacts-shiftwork-and-fatigue-safety-performance-miners
If you want help in reducing your workplace accidents due to fatigue, please don’t hesitate to contact us and we would be happy to assist.
