On 1 June 1877 a branch line was opened from here to St Ives, which was when the station was renamed 'St Erth'. The station building was reconstructed in granite and a second track was laid on the north side of the platform for branch line trains, but the main line still had only the one track. This was partly rectified in about 1894 when a loop line with its own platform was opened, but the line was only doubled eastwards to on 10 September 1899, and westwards to on 16 June 1929.