The Mayor of London, Ken Livingstone, recently unveiled a number of trials to be introduced by London Underground (LU) to cool the tube network, reveals Transport for London. New measures for this summer include the first full-scale trial of the award-winning groundwater cooling project at Victoria Tube station, the trial of a new 'bore hole' cooling technology at Stockwell station and new air-cooled trains.

London Underground is planning to use ice thermal storage to keep commuters cool on tube trains. The plan is to pass the train’s air supply over blocks of ice located beneath the train’s seats to cool the carriages. The solution is being considered for the Piccadilly Line. The scheme has been proposed because conventional air conditioning cannot be used in Tube tunnels as it would further increase temperatures. Under the system being developed for the Piccadilly Line, the ice store will be charged when the train is on the surface. Once inside the tunnels, the refrigeration plant will be switched off, enabling ice alone to cool the carriage air supply. When the train re-surfaces, the refrigeration units will switch on to re-freeze the store.

The Mayor and LU highlighted that the investment will take years, not months, to have a major impact. Ken Livingstone said: "London’s Tube network is the oldest in the world and its design makes cooling the system extremely difficult.” As for Tim O’Toole, LU’s Managing Director, he stated: “Cooling the Tube is a major and long-term engineering challenge.” 

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