Is rail cool enough?
Extreme heat events are becoming more frequent and severe in the UK. How can we ensure that our rail network can withstand its effects?
Claire Shooter Public Health Manager, RSSB
Last July, the UK saw temperatures exceed 40°C for the first time. This is a trend set to continue, with the Met Office projecting that very hot, very dry summers will increase in frequency. While the recommendation is typically to avoid non-essential travel during days of extreme heat, the reality is that many people—passengers and operations staff alike—are travelling or working on the network during these times.
There are a number of serious health implications for passengers, not to mention substantial risks for staff, when temperatures exceed roughly 25°C, and many of these are exacerbated by dehydration. For example, the immediate health impacts of very hot weather include heat rash, heat syncope (dizziness and fainting), and heat exhaustion, which can be serious and present a risk to life if not treated.
Beyond these physical effects of extreme heat, there are also several adverse psychological effects associated with elevated temperatures. Perhaps the most pertinent in terms of staff and passenger safety is cognitive impairment. Although research has found it difficult to gauge the specifics of this association, such as the safe temperature range and the degree of impairment present, there have been studies in similar industry areas from which we can learn.
For instance, a study among bus drivers in China observed that operating at 32°C, 36°C, and 40°C was safe only for 80, 73, and 53 minutes, respectively, if not mitigating action is taken. With UK temperatures soaring to these heights more often, enhancing ventilation for operations staff, encouraging the consumption of more water, and providing cool uniforms can all help mitigate the associated risks. However, there may be more industry can do to ensure safe operations at such temperatures—especially as our climate continues to change.
RSSB is supporting a research project in this area. In collaboration with DB ESG, RSSB is investigating the suitability and use of solar reflective materials on GB rolling stock. Existing thermal insulation systems are proving inadequate for the increasing frequency and severity of UK heatwaves, and they are often unable to cool carriages to an acceptable temperature.
Research project T1310 seeks to confirm if coating vehicle roofs with a more solar reflective paint can reduce the internal temperatures of these saloons. If proven useful, this could help keep staff and passengers cool during hot days.
Another challenge associated with extreme heat is its association with increased aggression. Studies suggest that people perceive others as more aggressive in uncomfortable heat, and respond more aggresively to others themselves. This may stem from feeling uncomfortably hot. For rail passengers an additional trigger could be heat-related equipment failure, such as signalling faults and buckled rails, causing travel delays.
Better understanding the effects of hot weather on people’s temperament can enable industry to anticipate and mitigate this rsk.
Rail is a key player in the fight against climate change, with a number of initiatives under way across the UK. Still, industry needs to act quickly to build a better awareness of the risks associated with periods of intense heat. Some risks are direct, while others are indirect—but all, unless mitigating actions are implemented, have the potential to cause harm.
What will be key is taking a holistic view at the network—including its equipment, rolling stock, and buildings—and devising a workable strategy for risk management during days of extreme heat. Various immediate solutions are already in place, and government legislation is now starting to reflect the need for longer-term plans. Protecting our staff and passengers is a key priority for industry, and equipping rail leaders with the knowledge and solutions to minimise the physical and psychological effects of extreme heat should now take centre stage.
RSSB examined the suitability of solar reflective materials for use on GB rolling stock. Our research sought to quantify how much interior carriage temperatures can be reduced compared to vehicles without solar reflective materials. It also considered whether this would reduce the power draw on air conditioning systems. Learn more about research project T1310.
Read the research
