In 2026, the primary manufacturer for the newest generation of London Underground trains is Siemens Mobility. Under a major contract worth approximately £1.5 billion, Siemens is currently producing the "2024 Stock" (also known as the New Tube for London) to replace the aging 1970s-era fleet on the Piccadilly Line. These new trains are being built at a state-of-the-art factory in Goole, East Yorkshire, as well as a facility in Vienna, Austria. Historically, London Underground trains have been built by various companies through the decades, including Alstom (which built the current Jubilee and Northern line fleets) and Bombardier (now part of Alstom, which built the S-Stock seen on the District, Circle, and Hammersmith & City lines). The new Siemens Inspiro-platform trains represent a massive tech leap, featuring the first-ever air conditioning on "deep-level" tube lines and a walkthrough design that increases capacity by 10%. This domestic manufacturing shift to Goole is a significant part of the UK's rail strategy to support local jobs while modernizing the world's oldest underground network.