Eurostar has updated its order for 50 double-decker Celestia trains to better withstand extreme heat, preparing for increasingly severe summers across Europe. The cross-Channel operator recently modified the terms of its €2 billion (£1.7 billion) contract with French manufacturer Alstom to ensure that onboard systems can operate effectively at temperatures up to 55 degrees Celsius, significantly higher than the original specification of 45 degrees Celsius.

The decision follows a spate of record-breaking heatwaves across Europe, particularly in France, where temperatures exceeded 40 degrees Celsius for several days, including a high of 44.3 degrees in Bordeaux. The new temperature threshold, dubbed the "Sahara option," incorporates enhanced air conditioning and upgraded components, including microprocessors designed to function reliably under extreme heat. Eurostar Chief Executive Gwendoline Cazenave explained that the trains, scheduled for delivery from 2031, are intended to remain in service for around 30 years, by which time such temperature extremes may become more common in northern Europe.

“Initially, we thought 45 degrees was sufficient given the geographic scope of our services, which include the UK, Germany, Switzerland, and northern France,” Cazenave said. “However, recent heatwaves showed us temperatures can rise well above that. Investing in trains capable of handling 55 degrees is more expensive, but it is necessary for long-term resilience.”

The updated trains will also increase capacity by approximately 20 percent to support upcoming direct routes to Geneva and Frankfurt. The improvements align with preparations for anticipated shifts in European climate patterns, with the European Commission’s climate directorate-general warning that heatwaves are both intensifying and becoming more frequent. Since 2000, 23 of the 30 most severe heatwaves recorded in Europe have taken place.

Eurostar is also enhancing its operational response to heat-related disruptions. Its “solstice plan,” now in its third year, was activated earlier than usual this season due to early heatwaves in spring. The plan involves continuous monitoring of air conditioning and water supplies on every train, prioritised maintenance slots to address cooling system failures, and protocols to ensure passenger safety during severe temperature events.

Heatwaves have already impacted Eurostar services this year, with approximately 10 percent of trains affected by delays and breakdowns. In one incident last month, passengers were stranded for over two hours without air conditioning on a train stalled in Belgium, leading to medical evacuations. Another service from Paris to Amsterdam was stalled for eight hours without power or cooling amid exceptional heat, prompting Eurostar to apologise and advise vulnerable travellers to postpone journeys during heatwave periods.

The company noted that extreme temperatures often require trains to operate at reduced speeds for safety reasons, as rails and overhead power lines can become vulnerable to damage. Similar mitigation strategies are used in countries with hotter climates, such as Saudi Arabia, where equipment and infrastructure have been adapted to endure harsh conditions.

As Europe confronts the challenges posed by climate change, Eurostar’s investments and operational updates reflect a broader effort within the rail industry to enhance infrastructure resilience and maintain reliable service in the face of rising temperatures.