The project involves upgrading major systems including HVAC, automatic train control, auxiliary power supply, brake control, communications and doors, as well as bogies on the 20-year-old articulated vehicles.

The work will be carried out at Alstom’s Mare Island Facility in Vallejo, California, where the first vehicle is due to arrive next month. Alstom says it expects the overhaul programme to create 45 jobs locally.

The programme is due to be completed in 2021.