When was Air Con First Introduced to the Underground?

We tend to take air conditioning for granted on the Underground and probably don’t give it a second thought – but back in the days before it was introduced, rail journeys often weren’t the comfortable experience we enjoy today.

Prior to 2010, conditions on the Tube could be hot and stuffy, making rail travel uncomfortable on sunny days, when the temperatures started to rise. Now, thanks to a programme of air conditioned trains (known as “S Stock”) being rolled out, the Underground is much more pleasant.

As a result of the addition of air-con for passenger carriages and driver cabs, the Underground provides a safer and more comfortable environment.

When was air con first introduced to the Underground?

London’s Tube network began to operate in 1863, making it the world’s oldest underground railway, but it took 146 years to find a way of keeping the carriages’ climate comfortable, whatever the weather! The first air-conditioned train finally arrived in 2009, at a depot in north-west London.

Known as “S8 Stock”, the prototype air-conditioned train was initially tested overnight between Watford and Amersham, via the Watford North Curve, on 9th November 2009. After testing was completed, the drivers’ training programme started in early January 2010.

After seven months, the first AC trains entered regular service on the Underground network on 31st July 2010. The first route was a shuttle service between Watford and Wembley Park. Air-conditioned trains were launched on the Metropolitan line from September 2010.

What were the new AC trains like?

The existing rolling stock on the Metropolitan line had been replaced by 58 air-conditioned trains by 2011. Then, on 6th July 2012, further AC trains began operating from Moorgate to Hammersmith. Some station platforms were lengthened to accommodate the new “S7 Stock” trains, which were longer than the old C69 and C77 trains they replaced.

New Tube trains had seven carriages and were 117 metres long, while the old ones had only six carriages and were 93 metres long. Lengthening the platforms wasn’t possible at some stations, such as Baker Street, so the trains had to have a door-opening mechanism whereby the ones at the end wouldn’t open at these stations.

The S7 trains were used at peak hours for the first time on 4th December 2012 and were soon operating the full service from Barking to Hammersmith within a week. By 2015, the new trains were rolled out on all the Circle and District Lines.

At the time of the first air-conditioned trains, Boris Johnson, the then Mayor of London, described it as a “milestone in the rebuilding of our transport system”.

Introducing air-conditioned Tube trains was the biggest single rolling-stock order to date in Britain, costing £1.5 billion, according to Transport for London.

How many rail routes have air-con today?

After the initial introduction of the new trains, Transport for London began developing methods of installing air-conditioning on London Underground’s deeper routes such as the Northern, Bakerloo and Piccadilly lines.

More key rail projects were launched by Transport for London, including the upgrade of the Jubilee Line to increase capacity by one-third and a £1.4 billion extension of the East London Line.

Currently, a number of lines have trains with AC, including all the S Stock trains on the Hammersmith and City, District, Circle and Metropolitan lines and the TfL Rail links between Hayes and Harlington Station and Paddington Station. The east line between Liverpool Street and Shenfield has new Crossrail purple trains, with the latest state-of-the-art air con.

On London Overground, the trains are fully air-conditioned, apart from the lines out of the Emerson Park branch, which have “air-cooled” trains, rather than air-conditioned. Nevertheless, they still feel comfortable in the heat.

The new trains with air-con are part of an ongoing rolling programme of improvements to the Underground that have been continuing since 2009. Transport for London is aiming to make £5 billion efficiency savings as part of its project.

Perhaps another more overlooked benefit of air conditioning in the London Underground is that it removes stale air that could be contaminated, thus providing proper ventilation that could help make the Tube safer during the current Covid-19 pandemic.

For further information about LH-PLC’s railway air conditioning services, contact us today through our handy online contact form.