BENGALURU: The first set of U-shaped girders, which facilitate the quicker laying of railway tracks, was cast at Doddajala yard on Saturday for one stretch of Bengaluru Metro’s Airport Line. U-girder technology has been adopted by Bangalore Metro Rail Corporation Limited, both for its Outer Ring Road Line and the K R Puram to Kempegowda International Airport Line, in place of the traditional box technology. The stretch where the girders have been cast now runs for 15.01 km from Air Force Station at Yelahanka to Airport Terminal 2 inside the KIA.