Sir Sadiq Khan is facing mounting pressure to accelerate the introduction of air conditioning on the London Underground as the capital endures its second heatwave of the year, with temperatures approaching 40°C on Wednesday. The mayor has been urged to resolve delays in new rolling stock for the Piccadilly line, which was originally expected to bring air-conditioned trains to a deep Tube line for the first time. Opposition politicians have emphasised that this must be a step toward equipping the entire Underground network with air conditioning as climate change makes hotter weather more frequent.
Delays to New Trains
The first of 94 new Piccadilly line trains was initially slated to enter service in late 2023, but the deadline was pushed back to the second half of 2024 and is now expected between December 2024 and June 2025. Similarly, the rollout of 54 new air-conditioned trains on the Docklands Light Railway (DLR) began last autumn but was halted after one train overshot its intended stopping point. These setbacks mean that no new air-conditioned trains have been introduced on the Underground for nine years.
Conservative London Assembly Member Thomas Turrell said: “Londoners could have been enjoying air-conditioned Piccadilly and DLR trains this week, but instead they are sweating to death because the Mayor has failed in this basic responsibility. If by next summer we are still in this position, the Mayor will have undoubtedly failed Londoners in his mission to keep them safe and comfortable on public transport.”
Current Air-Conditioned Coverage
Currently, 192 out of 620 Tube trains have air conditioning, covering 40 per cent of the network. Lines with air-conditioned trains include the Circle, Hammersmith & City, District, and Metropolitan, as well as the Elizabeth line, London Overground, Northern City line, Thameslink, and trams. Lines without air conditioning are the Central, Bakerloo, Jubilee, Victoria, Waterloo & City, Piccadilly, and Northern.
Caroline Russell, Leader of the Green Group on the London Assembly, stressed: “With sweltering temperatures becoming more common, London is expected to develop a climate comparable to southern European cities, such as Barcelona, over the coming years. We need air conditioning on every Tube and train to keep passengers and staff safe during periods of extreme heat.”
Station Cooling Issues
Londoners are also enduring sweltering conditions at Tube stations, where cooling equipment has struggled to cope with heatwaves. Over a decade ago, systems were upgraded at Oxford Circus with chiller units to blow out cool air, and cold water from a borehole was piped into units to reduce the temperature at Green Park. However, the cooling element at Oxford Circus failed in 2017, and a similar situation occurred at Green Park. Fans are installed in some stations to mitigate temperatures, but Transport for London (TfL) said it is prioritising conditions for passengers on trains.
TfL attributed the delays to the “short-term and stop-start” nature of funding over recent years, which forced “difficult decisions” and “carefully prioritising” investment. Nick Dent, TfL’s director of customer operations, said: “We’re working to ensure our transport services remain resilient in the face of more extreme and frequent hot weather events. We are investing millions as part of our continuous work to improve the network, which includes introducing new trains to meet growing customer numbers whilst providing more comfortable journeys. We have implemented energy efficient solutions on new trains, which reduce the heat generated. We’re constantly looking at how innovative solutions can be rolled more widely on the transport network to ensure more passengers experience cool and comfortable journeys in the summer.”
Political Responses
Liberal Democrat transport spokesperson Olly Glover MP said: “With four lines on the Underground network running with trains over 30 years old, including the Central Line, one of the busiest, warm words and advice about looking out for each other simply doesn’t cut it. Sadiq Khan must urgently address these chronic issues and accelerate the rollout of air-conditioning across the network and look to our European neighbours with similar transport networks, such as Madrid, who have experience of this.”
TfL says the delay to the new Piccadilly trains is due to “the complexity of introducing entirely new trains onto ageing infrastructure,” with some parts of the line around 120 years old.
