Metro Railway is upgrading the third rail on its oldest corridor, the Blue Line between New Garia and Dakshineswar, to enhance energy efficiency and enable trains to run at shorter intervals. The third rail, which supplies power to the trains, is being replaced in phases with an aluminium version, starting at Maidan and Girish Park stations. According to a Metro official, aluminium is a superior conductor of electricity compared to steel. This upgrade is expected to minimise system voltage drops and energy losses, resulting in faster train acceleration. The official stated that the aluminium third rail would reduce energy loss by 84 per cent, saving approximately Rs 10 million per kilometre annually and cutting carbon emissions by 50,000 tons over its lifetime. Preparatory work has begun at Girish Park and Maidan stations, carried out overnight after commercial services end. The main components, shipped from Hamburg, Germany, arrived in Calcutta in late July and are anticipated to reach the installation sites shortly. The spokesperson noted that the delivered material will cover around 5 kilometres of work and that the entire 35-kilometer Blue Line is expected to be completed in two years. Currently, train intervals during rush hours are about five minutes, but with the aluminium third rail, the frequency could improve to every two-and-a-half minutes. In addition to the aluminum third rail, more electrical substations will be necessary to achieve the desired rush-hour frequency, as these substations provide power to the third rail.