To its credit, TfL has made many efforts over the years to deal with the sizzling tunnel problem, including: fastening cooling panels to the tunnel walls. Panels that permeate water to remove heat from the air were implemented as part of a trial in 2022, although they are not currently in operate. Paul argues that such a system could be too steep.
Hassan Hemida from the University of Birmingham says Paul’s water cooling technology is a “good idea”, although it remains to be seen how much heat it can actually remove from a real, busy tube station full of people.
Some railways simply push the limits of our cooling capacity, Hemida says. He gives the example of bullet trains traveling at, say, 400 kilometers per hour. They push air at high speed, which means the air pressure surrounding the heating, ventilation and air conditioning (HVAC) equipment on the roofs of these trains may drop significantly. “Then you can’t suck air into the HVAC system,” he says. Ultimately, this may cause your air conditioner to fail. “My colleagues from China contacted me and want to find a solution to this problem,” adds Hemida.
However, more and more train operators are adopting air conditioning systems as standard. For example, London’s still relatively up-to-date Elizabeth Line has air conditioning. And a spokesman for Škoda Transportation, which recently introduced air conditioning to the market metro trains in the capital of Bulgariasays: “Basically every vehicle we produce today is equipped with air conditioning.” Sharon Hedges, senior engagement manager at Transport Focus, an industry watchdog, adds: “When people are thinking about purchasing new rolling stock, these are the issues that should be top of mind now.”
Heatwaves are one thing in the UK. What about the Egyptian desert? German technology company Siemens is providing Egypt with a up-to-date set of high-speed trains that can run at speeds of up to 230 kilometers per hour. The company’s Velaro trains are used in many places in Europe, but in the case of Egypt, Siemens has really put them to the test. Last summer, the company took one of the trains to a test facility in Austria and exposed it to harsh conditions, including temperatures of up to 60 degrees Celsius and mighty winds. “We achieve an internal temperature of 26 degrees in the hottest outdoor conditions,” says Björn Buchholz, director of HVAC systems and doors.