Piccadilly Line Train Rollout Delayed Until 2027

Transport for London (TfL) has confirmed that the introduction of new Piccadilly Line trains has been delayed for a second time, with entry into service now expected in the first half of 2027.

The 94 new trains, being manufactured by Siemens Mobility, were originally scheduled to enter service in late 2025. In June that year, TfL and Siemens announced a delay pushing the rollout to late 2026 following issues identified during testing. The programme has now slipped further as additional “complexities” are addressed.

TfL said the extended testing period had highlighted further technical challenges, particularly given the age of the Piccadilly Line infrastructure, parts of which are nearly 120 years old.

Stuart Harvey, TfL’s Chief Capital Officer, said safety remained the overriding priority.

“The programme of work that we are undertaking to bring these game-changing trains to London is hugely complex and is underpinned by our steadfast commitment to safety,” he said.

He added that while the delivery schedule had changed, teams were continuing to work intensively to resolve outstanding issues.

The new trains will replace 86 units introduced in 1973 and form part of TfL’s wider £2.9BN modernisation programme. Four trains have so far been delivered and are undergoing weekend and overnight testing, with some modifications already made to ensure compatibility with the line.

Further closures are expected over the coming months to allow continued testing. TfL said the extended programme would enable both organisations to assess whether additional software or system changes are required.

Most of the fleet will be built at Siemens Mobility’s Goole Rail Village in East Yorkshire.

Aglaja Schneider, joint CEO of Siemens Mobility UKI, acknowledged the delay but said the trains would ultimately “transform travel for millions of people” once in service.