How to prevent another European transport meltdown | MarketingwithAnoy

As if flight and train cancellations due to strikes and staff shortages didn’t disrupt travelers enough this summer, the European heatwave came to add to the travel chaos. Extreme heat can be dangerous to human health – even fatal – but it also affects the built environment. It can cause metals and asphalt surfaces to expand and warp, making roads, rails and runways difficult or dangerous to use. This disrupted thousands of journeys this summer.

The fact that rails can buckle and asphalt “melt” – or rather soften and deform – became evident in July, when temperatures rose above 40 degrees Celsius in many European countries, setting many new records. On July 18, a small section of the runway at London Luton Airport in the United Kingdom heated up so much that it began to lift. The runway had to be closed for two hours while engineers repaired the surface, with some flights diverted and others cancelled. Across Europe, hundreds of train services were canceled due to heat warping the rails.

Due to climate change, heat waves are becoming more intense and more frequent, so the transport infrastructure needs to be adapted. There are already projects underway to keep infrastructure cooler during heat waves – many are simple concepts involving plants, paint or purpose-built shade. Meanwhile, materials scientists can offer more complex solutions, such as heat-resistant metals. But updating the infrastructure is neither easy nor cheap.

Railways and roads are particularly vulnerable to heat, says Giovanni Forzieri, assistant professor of civil and environmental engineering at the University of Florence. In 2018, Forzieri and his colleagues investigated how heat waves and other climate extremes – such as floods, wildfires and windstorms – could damage European infrastructure in the future. Currently, Europe’s transport sector bears 800 million euros ($820 million) in climate-related damages per year, but by the last decades of the century, researchers estimate that figure will have reached 11.9 billion euros ($12.2 billion). Around 90 percent of the damage will be caused by heat waves.

With railways, the difficulty is that steel rails can get 20 degrees Celsius hotter than the ambient temperature, and are therefore susceptible to temperature extremes. So before laying a new track, steel rails are heated and then cooled in a controlled manner to make them withstand higher temperatures, with different treatments that allow rails to operate in different temperature windows. In the UK, rails operate stress-free around summer temperatures of 27 degrees Celsius.

But if it gets too hot, the rails expand and become constrained by the anchoring that holds them in place, putting them under stress and potentially leading to buckling, where the rails are bent out of shape. Lowering trains can reduce the chance of this happening as lower speed trains put less pressure on the rails. That’s why network operators across Europe had to introduce temporary speed restrictions that led to costly delays and cancellations this summer.

One solution is to paint the rails white, which reflects sunlight off them and can keep the rails 5 to 10 degrees Celsius cooler. In the UK, Spain and Switzerland, operators had already started doing this ahead of the heatwave.

Of course, many parts of Europe regularly see temperatures above 27 degrees, and manufactures their rails to work in warmer temperature windows. But if rails in places like the UK are replaced with ones suited to warmer climates, they may not be able to withstand the low temperatures of winter. Steel contracts and becomes brittle when exposed to cold, meaning that rails can crack if placed under pressure when it is colder than their operating window. “It’s a very difficult situation because the temperature ranges are much wider in countries like the UK,” says Kiran Tota-Maharaj, a reader in civil and environmental engineering at Aston University in Birmingham.

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