 The remaining forty eight S sets were gradually replaced by twenty four eight-carriage B set Waratah trains throughout the course of 2018 and June 2019, with 14 S set carriages being retained for heritage purposes.6 S sets were to be kept for emergencies but as there was enough air-conditioned rollingstock available, none have been kept for that purpose.The new B sets replaced timetabled K set runs, while the K sets moved on to S set runs.