News, Culture & Society

Baking on the Bakerloo line? TFL trials new Tube station cooling system in wake of UK heatwave

Anyone who regularly travels on London’s Tube network in the summer will no doubt have spent some time baking on the Bakerloo line, or perspiring on the Piccadilly.

But passengers travelling on the so-called ‘deep’ Tube network could soon be treated to a breath of fresh air while they are waiting on platforms. 

Transport for London (TfL) has started trialling a ‘state-of-the-art’ cooling panel on a disused platform at Holborn station, to test its suitability for reducing temperatures on the Bakerloo, Central, Jubilee, Northern, Piccadilly, Victoria and Waterloo & City lines.

The panel works by circulating cold water around pipework within a curved metal structure to chill it. This structure then cools the air around it, which is blown out through gaps in the panel’s structure using an industrial-sized fan.

TfL claims the cooling panel could provide cooler air to passengers waiting on platforms, as well as mitigating potential temperature increases associated with running an increased number of trains on the Piccadilly line, as part of the line’s future capacity upgrade. 

In recent tests on a prototype cooling panel in a lab environment, an air temperature reduction of 10 to 15°C (18 to 27°F) in the vicinity of the panel was achieved.

TfL is now keen to see if this can be replicated on the disused platform at Holborn, which mimics the live environment that these panels would operate in. 

The trial comes as the UK experienced its hottest temperatures on record earlier this week, with temperatures hitting 40.2°C (104.4°F) at London Heathrow Airport on Tuesday.

The panel works by circulating cold water around pipework within a curved metal structure to chill it. This structure then cools the air around it, which is blown out through gaps in the panel’s structure using an industrial-sized fan.

TfL has started trialling the cooling panel on a disused platform at Holborn station, to test its suitability for reducing temperatures on the Bakerloo, Central, Jubilee, Northern, Piccadilly, Victoria and Waterloo & City lines

TfL has started trialling the cooling panel on a disused platform at Holborn station, to test its suitability for reducing temperatures on the Bakerloo, Central, Jubilee, Northern, Piccadilly, Victoria and Waterloo & City lines

How is the cooling panel different from conventional air conditioning? 

Due to the restraints of the deep tube platforms, conventional air conditioning would not be effective.

This is because conventional air conditioning works by removing the heat from an environment and releasing it outside. 

Due to the depth of the platforms, there is no way to release this heat, other than onto neighbouring platforms of tunnels. 

To avoid this heat causing problems elsewhere on the network, instead of taking excess heat from the platforms, cooled water is used to pump cold water through the panels. 

Station air is then blown through these panels and is cooled by the water temperature. 

‘This innovative trial is taking place as we are experiencing record high temperatures,’ said Paul Judge, TfL’s Project Director for the Piccadilly Line Upgrade.

‘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.’

In the past it has been challenging to lower temperatures on the deep Tube lines, as traditional cooling systems have proved prohibitively expensive and difficult to install within the 120-year-old tunnels and stations. 

The aim of the new cooling panels is to significantly out-perform the existing Platform Air Handling Units, which are currently installed at some stations on the deep Tube network. 

Initial results show that the new cooling panels are much better equipped to operate in the unique conditions of the deep Tube environment, according to TfL. 

If the trial on the disused platform at Holborn is successful, the next step would be for TfL to test the panel at Knightsbridge station, which is open to customers.

The panels then potentially could be introduced at four additional stations on the Piccadilly line – Green Park, Holborn, Leicester Square and Piccadilly Circus.

The Piccadilly line was chosen for this trial as when new, air-conditioned trains with walk-through carriages are introduced to the line from 2025, the current fleet will be gradually withdrawn from service and the frequency of trains in peak hours will rise from 24 to 27 trains per hour from mid-2027.

This is a train every 135 seconds at the busiest times, and represents a 23 per cent increase in peak service capacity. 

TfL hopes to eventually re-signal the entire line, meaning it could increase train frequencies on the Piccadilly line to 33 and then 36 trains per hour. 

It is at this point that additional cooling at five Piccadilly line stations would be necessary, according to TfL’s modelling.

‘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,’ said Mr Judge.

‘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.’

In recent tests on a prototype cooling panel in a lab environment, an air temperature reduction of 10 to 15°C (18 to 27°F) in the vicinity of the panel was achieved. TfL is now keen to see if this can be replicated on the disused platform at Holborn, which mimics the live environment that these panels would operate in.

In recent tests on a prototype cooling panel in a lab environment, an air temperature reduction of 10 to 15°C (18 to 27°F) in the vicinity of the panel was achieved. TfL is now keen to see if this can be replicated on the disused platform at Holborn, which mimics the live environment that these panels would operate in.

What cooling is there currently on the Tube? 

There are currently 192 air-conditioned Tube trains covering 40 per cent of the Underground network and there are enhanced tunnel ventilation systems on both the Victoria and Jubilee lines. 

All London Overground and Elizabeth line trains are air-conditioned.

On older parts of the Tube network which have fewer ventilation shafts, TfL has introduced a range of station cooling systems including industrial-sized fans and chiller units to pump in cold air.

TfL emphasises that these plans are all subject to it securing a long-term funding settlement from the Government.

The trial is part of the Government’s TIES Living Lab programme, a collaboration of 25 partners focusing on 10 infrastructure, data research and digital demonstrator projects, of which the cooling panels are one. 

The cooling panel project, which has been designed by TfL and developed by SRC Infrastructure, was 70 per cent funded by the Department for Transport and Innovate UK. 

However, progressing the trial at other locations is ultimately subject to TfL having sufficient long-term capital funding available.

If no further investment is provided, only projects already underway or those required to be compliant with safety and other statutory regulations will continue – meaning no new investment by TfL at all in the transport network. 

This would mean that while the new Piccadilly line trains, which are currently on order, will be honoured, any new order for Bakerloo and Central line trains to replace the ageing fleet would be delayed by a further 10 years until at least 2040.

There are currently 192 air-conditioned Tube trains covering 40 per cent of the Underground network and there are enhanced tunnel ventilation systems on both the Victoria and Jubilee lines. 

All London Overground and Elizabeth line trains are air-conditioned.

On older parts of the Tube network which have fewer ventilation shafts, TfL has introduced a range of station cooling systems including industrial-sized fans and chiller units to pump in cold air.

BILLIONS MORE WILL NEED ACCESS TO AIR CONDITIONING AS EXTREME HEAT RISES 

As extreme heatwaves ravage the US, Europe and Africa, killing thousands, scientists warn that the worst is still to come. 

With countries continuing to pump greenhouse gases into the atmosphere, experts warn that this summer’s sweltering temperatures may seem mild in 30 years.

Air conditioning, a technology many take for granted in the world’s wealthiest nations, is a life-saving tool during extreme heatwaves. 

However, only about 8 per cent of the 2.8 billion people living in the hottest – and often poorest – parts of the world currently have it in their homes.

In a recent paper, a team of researchers from the Harvard modelled the future demand for air conditioning as days with extreme heat increase globally. 

They found a massive gap between current air conditioning capacity and what will be needed by 2050 to save lives, especially in low-income and developing countries.

The researchers estimated that, on average, at least 70 per cent of the population in several countries will require air conditioning by 2050 if the rate of emissions continues to increase, with that number even higher in equatorial countries like India and Indonesia. 

Even if the world meets the emissions thresholds laid out in the Paris Climate Accords –which it’s not on track to do – an average of 40 per cent to 50 per cent of the population in many of the world’s warmest countries will still require air conditioning.

***
Read more at DailyMail.co.uk