Eurostar has decided to significantly upgrade the climate control systems for its next-generation fleet, well before the first trains enter production. The decision reflects growing concern that temperature thresholds set during the design phase could be obsolete by the time the rolling stock enters service, given the accelerating pace of extreme weather across Europe.
Sahara-grade cooling for a northern network
The new Eurostar Celestia, the operator’s variant of the Alstom Avelia Horizon platform, was initially specified with air conditioning rated for operation in ambient temperatures of up to 45°C. That ceiling was considered sufficient for a network concentrated in northern Europe. However, the blistering heat recorded in France during recent summers prompted a swift reappraisal. According to reporting by The Telegraph, Eurostar has now opted for what it calls the “Sahara option,” mandating a substantially more powerful cooling system before manufacturing begins.
Leveraging a Moroccan blueprint
The engineering shift is made simpler by the fact that the Avelia Horizon is already being adapted for extreme heat elsewhere. Morocco’s national railway, ONCF, has ordered 18 of the same trainsets to expand its high-speed network, where coping with desert temperatures is a baseline requirement. In the shade, Moroccan cities such as Marrakesh regularly see July temperatures around 44°C, values that would once have seemed remote from Eurostar’s operating environment but are now within plausible range. Eurostar can draw directly on the technical work Alstom must complete for the ONCF fleet, accelerating the upgrade and avoiding a bespoke redesign.
Ageing fleet meets a warming climate
The urgency of the upgrade is sharpened by the age of Eurostar’s current trains. Some are now more than 30 years old and are expected to remain in service into the 2030s because rolling stock cannot be swapped out at will. The Celestia fleet, due in the early 2030s, will likely have to run into the 2060s or even the 2070s. Ensuring those trains can handle temperatures well beyond today’s extremes is therefore a core operational requirement, not a theoretical precaution.
Rail operators across Europe have been raising cooling specifications for years. Deutsche Bahn’s air conditioning systems on earlier ICE generations, for example, were once limited to a narrow band of 32–35°C, leading to repeated failures during hot spells and accusations that maintenance had been pared back to save costs. More recent designs, including the ICE 4, have pushed the rated range to 45°C. Eurostar’s Sahara-grade choice signals a further step in adapting rail infrastructure to a rapidly shifting climate.