TfL has announced its intention to award a contract worth around £1.5bn to Siemens Mobility to design and build 94 new-generation Tube trains to operate on the Piccadilly line, used by over 700,000 customers use every day.

Due to limited fleet size and old signalling technology, TfL’s ability to boost capacity across the line has been restricted for many decades.

The investment is intended to support London’s growing population, which is expected to grow to 10.8 million by 2041.

Construction of the trains will involve 22 UK-based suppliers that have been chosen to potentially work with Siemens Mobility. At least 50 new apprentice and graduate positions could also be created.

“Outdated rolling stock, signalling and control systems across the four lines will be replaced as part of the upgrade programme.”

This contract is considered as a major step enabling Siemens Mobility to progress its plan to construct a new factory in Goole, East Yorkshire, to manufacture and commission trains.

The Siemens Mobility facility will employ up to 700 people in engineering and manufacturing roles and up to 250 more people during the construction phase of the factory.

TfL will team up with Siemens Mobility Limited to maximise the number of Piccadilly line trains being developed at the facility.

The order is the first under the Deep Tube Upgrade Programme. It will lead to the replacement of the complete 1970s Piccadilly line fleet.

Outdated rolling stock, signalling and control systems across the four lines will be replaced as part of the upgrade programme. In total, it will deliver a 36% increase in capacity across the lines by 2035.

From 2023, 94 new Inspiro trains will be delivered on the Piccadilly line, allowing up to 27 trains-per-hour (tph) to run at peak times by the end of 2026. This would be an increase from the present service level of 24tph.

New trains will offer a range of new design features that will strengthen customer comfort. Each new train will be 6m longer than the existing trains operating on the Piccadilly line. These trains will have walk-through, completely air-conditioned carriages and will optimise space constraints in the narrow Deep Tube tunnels.