Piccadilly line upgrade

Improving the trains

New walk-through and air-conditioned trains will make Piccadilly line journeys faster, more frequent and more reliable. The new trains will begin to replace the existing 1970s fleet from 2025.

The 94 new, spacious 'Inspiro London' trains will feature:

  • More room to allow for a more frequent and reliable service - it will take less time at each station for people to get on and off
  • Wider doors and walk-through, air-conditioned carriages with improved access from the platform to train for a more comfortable and accessible journey
  • Designs with sustainability in mind, reducing energy consumption by 20%

The trains currently running on the Piccadilly line have become increasingly unreliable and expensive to maintain. They will be 50 years old by the time they are replaced.

The new trains will allow us to run more trains per hour during peak times from 2027 - up from 24 to 27. This means a train every 135 seconds at the busiest times - a 23% increase in the number of trains running at those times.

Supporting the UK economy

Half of the new train fleet will be built in Goole, East Yorkshire, with up to 700 people employed in engineering and manufacturing roles, 250 in the construction phase and 1700 in the broader supply chain.

The order for the new Piccadilly line trains, with further investment in signalling, would support 25,000 new jobs in London. It would also support the next generation of transport workers through apprenticeship places created both by Siemens Mobility, TfL and the wider supply chain.

Depots and stabling upgrade

To accommodate the new trains, we need to change maintenance procedures, facilities and stabling at the Cockfosters depot, Northfields depot and South Harrow sidings. Check back here for more on how these schemes might impact each local community.

South Harrow sidings

  • Requires an additional 6 longer stabling berths with a new southern connection onto the Piccadilly line
  • Works at South Harrow started in December 2020

Northfields depot

  • Requires additional stabling berths, a new maintenance shed and cleaning shed
  • Construction includes the demolition of the existing maintenance shed and cleaning sheds
  • Work on the scheme started in 2022

Cockfosters depot

  • Requires additional stabling berths, a new maintenance shed, cleaning shed and train wash
  • Construction will include the demolition of the existing cleaning shed and maintenance shed for the new stabling berths
  • Works to build the maintenance and cleaning shed are expected to start in 2022 and last 28 months

Works at Cockfosters

The depot and track layouts at Cockfosters will get a major upgrade and remodelling. This is needed to increase stabling capacity and provide modern train maintenance, repair and cleaning facilities to support the new train. See our detailed plans for Cockfosters depot.

Reducing carbon, the environment and sustainability were at the forefront of the design of the new depot, in line with the Mayor's Transport Strategy. This includes the use of:

  • A low maintenance extensive green roof on the new maintenance/cleaning shed
  • Solar panels and natural lighting to reduce energy demand by 35% - in line with the London Environmental Plan
  • Rainwater harvesting and water re-use from the roof of the maintenance shed to reduce the volume of runoff water from the site during storms
cgi of green roofs at cockfosters sidings

Planning process

We have permitted development rights for the works at Cockfosters depot and are applying to the London Borough of Enfield to use these rights. Enfield will assess the proposal within the scope of relevant legislation.

We have discussed the principle of the proposed works with Enfield Council, including our commitment to minimising the impact on local people.

Contact us

Get in touch If you have any questions about the works.


 Charges apply 0343 222 1234 (24 hours)

TfL Customer Services
4th Floor
14 Pier Walk
London SE10 0ES