Complex sentence: Its single platform, opened on on 1 August 1849 was built to the south of, and adjacent to, the main part of the station, this formed the predecessors of today's through platforms 13 and 14.
Split into simpler sentences: Its single platform, opened on on 1 August 1849 was built to the south of, and adjacent to, the main part of the station. This formed the predecessors of today's through platforms 13 and 14.