First Night Shifts: Guidance for Managing Fatigue Risk
The investigation into the 2010 freight train roll-back incident at Shap looked at tools that assess rosters for fatigue. It found that different tools made different predictions about fatigue based on assumptions about whether people adjust to night shifts and experience less fatigue over time, or whether they are likely to become increasingly tired over consecutive days. If a person’s body clock is adjusted to being awake during the day and asleep at night they will struggle to stay alert during their first few night shifts. In addition, if a person adopts their normal daytime routine leading up to their first night, by the end of that shift they will have been awake for a very long time. And we know that when people have been awake for 17 hours they start to show signs of impairment that are similar to being over the drink-drive limit.
We have developed new guidance to help the rail industry reduce fatigue risk. This guidance outlines the steps organisations can take to reduce fatigue risk, such as:
- ensuring the first night shift is no more than eight hours, and if this is not possible then providing more frequent breaks
- adopting a more positive attitude to napping during the first night shift – studies show even short naps of 20 minutes can be effective
- encouraging staff to sleep, if they can, before their shift
- considering managing workload levels and avoiding repetitive monotonous tasks, especially when people are least alert, between 4am and 6am
The guidance also makes recommendations regarding the use of bright lights or blue light in mess or break out rooms that can help increase alertness, and the importance of educating individuals about the long-term effects of caffeine and responsible use.