Metrowagonmash was awarded a €219.2m contract last August to modernise the fleet of six-car trains used on Line 3, which were built by the same supplier in the late 1970s.

The upgrade, which is intended to prolong the life of the fleet by 20 years, includes new cabs, electronic control, automatic fire detection and sprinkler systems, connecting gangways, emergency doors, regenerative braking, forced air ventilation, modern interiors, CCTV and multi-purpose areas. New doors and seating are also being fitted.

The programme encompasses a total of 222 vehicles, including 185 type 81-714/71, 10 type 81-717.2/714.2, and 27 Ev3 cars.