New state-of-the-art trains for the Piccadilly line are set to begin testing this summer ahead of their launch for passengers in the second half of 2026, Transport for London (TfL) has confirmed.
The upgrade will bring major improvements to one of the Underground’s busiest lines, including more space, improved comfort, on-board CCTV, walk-through air-conditioned carriages, and real-time digital displays. The trains will offer 10% more capacity and wider doors to make boarding easier.
South Harrow and Rayners Lane are the only stations in the borough of Harrow on the Piccadilly line, with nearby stations including Sudbury Hill and Alperton, which are also frequently used by Harrow residents.
Stuart Harvey, TfL’s Chief Capital Officer, said: “We’re proud and excited that these innovative new trains on the Piccadilly line will have a transformative effect for London. This hugely complex project will boost capacity and make journeys more accessible and more comfortable for millions of people. This is an ambitious project with new 21st century trains providing engineering challenges in both building and introduction into service on a 20th century railway and it is critical that we ensure that safety comes first and that the trains are in top condition when they begin to service London.
“It will obviously be disappointing for customers that they will have to wait a bit longer for the new trains, and I regret that. But I would like to assure Londoners and visitors to our city that we are working extremely closely with Siemens to ensure that the new trains can be introduced as soon as possible in the second half of next year.”
The trains are being built by Siemens Mobility, supporting nearly 1,000 skilled jobs in Goole and across the UK. They will be lighter and more energy-efficient, using 20% less energy and offering a smoother ride.
Testing had been delayed due to the complexity of integrating the new design with existing infrastructure—some of which is more than a century old—but is now expected to start this summer. This will ensure all systems are safe and reliable before passenger rollout.
Sambit Banerjee, Joint CEO at Siemens Mobility, said: “We’re working really hard with TfL to deliver the new Piccadilly line trains that are going to transform travel for people in London. Any project like this is complicated – we’re bringing state-of-the-art, air-conditioned, walk-through trains into tunnels that were built 120 years ago.
“We’re sorry we can’t have our innovative trains running for passengers even sooner but, once they’re in service, the technology on these new trains will bring smoother, greener and more comfortable journeys for Londoners for the next 30 or more years.”
TfL says the new fleet will help support new housing, jobs, and economic growth in the capital as part of a broader investment in London’s transport infrastructure.
Chris Mitchell is the founder and editor of Harrow Online, Harrow’s leading local news platform.
He launched Harrow Online in 2010 as a Facebook page sharing local news and information. Since then, it has grown into a trusted source for breaking news, crime, council decisions, planning, transport, business and community stories across the borough.
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