TfL trialling Tube Line cooling system after historic heatwave

After the recent heatwave, this week where the UK experienced its hottest temperatures on record, Transport for London (TfL) is now trialling a state-of-the-art cooling panel. This trial is taking place on a disused platform at Holborn Station to evaluate its suitability for reducing temperatures on the deep Tube network.

The cooling panel will aim to produce cooler air to passengers waiting on platforms, as well as the mitigation of the potential temperature rises that come with running an increased number of trains on the Piccadilly line, as part of the line’s future capacity upgrade.

This innovative cooling system works through the circulation of cold water around pipework within a curved metal structure to chill it through the help of an industrial sized fan.

The implementation of this new panel system could halve the current operational and maintenance costs, compared to existing technology used to manage temperatures on Tube lines.

This cooling panel project was 70% funded through the Department for Transport and Innovate UK, with the convection cooling system being designed by TfL and developed by SRC Infrastructure, which also managed its build.

The success of this Holborn based trial, as well as further funding being available, will determine whether TfL could expand this technology across their network. Further testing would be required in a station with live passenger travel (Knightsbridge) before these panels could be outsourced to four additional stations on the piccadilly line, being Green Park, Holborn, Leicester Square and Piccadilly Circus.

The Piccadilly Line has been the focal point of this trial due to the plans for its current fleet of rolling stock to be gradually withdrawn from the network and replaced with new, air-conditioned trains with walk-through carriages are introduced to the line from 2025. This change to the fleet will see the line capacity increased from 24 to 27 trains per hour from mid-2027, seeing a train every 135 seconds at the busiest times representing a 23% increase. The increase in line capacity will require a state-of-the-art cooling system to mitigate any future heat related disruptions to services.

Historically, Tube Line temperatures have been difficult to manage due to traditional colling systems proving prohibitively expensive as well as being difficult to install within the 120-year-old tunnels and stations. With the current prototype panel, an air temperature reduction of 10-15 degrees can be achieved, as shown through lab-based testing. The TfL are now keen replicate this success through the Holborn trial and then look to expand further through the network.

Paul Judge, TfL’s Project Director for the Piccadilly Line Upgrade, said:

 “This innovative trial is taking place as we are experiencing record high temperatures. This new technology could play an important role in ensuring we are doing everything we can to protect TfL’s network against future temperature increases, helping to keep staff and customers safe and comfortable.

“The TIES Living Lab project has given us a great collaborative platform for sharing innovative ideas, data, and good practice with a range of suppliers. The cooling panel project is supporting the Piccadilly Line Upgrade, which will see new state-of-the-art trains with more space, air-conditioning, walk-through carriages, and improved accessibility running at greater frequencies on the line.

“By seeking innovative solutions to cool platforms on the deep Tube network, we will be able to support future Piccadilly line train frequency increases with the possibility that the technology could be used on other Underground lines.” 

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