In October 1960, work on a new Spencer Street station commenced, sparked by the construction of the interstate standard gauge line to Sydney. A station building was constructed which largely replaced the 1880s iron sheds, and a new platform number 1 was built. The passenger subway which had been constructed as part of the 1918 works was extended to include access to country platforms. In connection with the construction of the underground loop, platforms 9 and 10 were rebuilt as part of the suburban section of the station, and a new double-track viaduct was constructed between Spencer Street and Flinders Street station, alongside the original one, bringing to six the number of tracks connecting the two stations. At the same time, the four older tracks were resignalled for bi-directional operation.