LUL then invited Alstom, Bombardier and Siemens Mobility to develop a new concept of lightweight, low-energy, semi-articulated train for the deep-level lines, provisionally called "Evo" (for 'evolution'). Siemens publicised an outline design featuring air-conditioning and battery power to enable the train to run on to the next station if third and fourth rail power were lost. It would have a lower floor and higher passenger capacity than the present tube stock. There would be a weight saving of 30 tonnes, and the trains would be more energy-efficient with air-conditioning included, or more energy-efficient without it. Siemens Mobility was awarded a £1.5 billion contract in June 2018 to produce the new trains at a planned factory in Goole, East Yorkshire.
LUL then invited Alstom, Bombardier and Siemens Mobility to develop a new concept of lightweight, low-energy, semi-articulated trai.n for the deep-level lines, provisionally called "Evo" (for 'evolution'). Siemens publicised an outline design featuring air-conditioning and battery power to enable the train to run on .to the next station if third and fourth rail power were lost. It would have a lower floor and higher passenger capacity than the present tube stock. There would be a weight saving of 30 tonnes, and the trains would be more energy-efficient with air-conditioning included, or more energy-efficient without it. Siemens Mobility was awarded a £1.5 billion contract in June 2018 to produce the new trains at a planned factory in Goole, East Yorkshire.