Kolkata, Aug 10 : A third rail system will be shortly introduced in Kolkata Railways, the oldest metro rail services in the country, leading to increase in train frequency during the peak hours. Railways sources said the third rail system had been adapted by the metro railways services authorities in global cities like London, Moscow and Singapore, among others. Chief public relations officer of Kolkata Metro Railways Kaushik Mitra said that the initiative of introducing the third rail system is expected to be completed within the next two years. Railways sources said that a tender has been floated for the purpose. As soon as the process is completed, work for installation of the third rail system will start immediately. Instead of using the traditional steel for the railway tracks, aluminum-made tracks will be installed in the third rail system. This will make the tracks more heat-resistant and result in lesser electricity consumption. City-based civil engineer Pradipta Mitra said that the longevity factor for the aluminum-made tracks is much higher than the traditional steel-made tracks since there is no question of rust involved. "Secondly aluminum as a metal is better resistant to friction of the wheels, which also enables such tracks to have a better longevity," Mitra added. /IANS