In 1985, the line was duplicated through to East Hills and on 21 December 1987 extended to Glenfield to connect with the Main South Line, allowing through services to and from Campbelltown. A new station was provided at Holsworthy, and East Hills station was rebuilt with the addition of a third platform. When services commenced on 21 December 1987, there were only limited services from Campbelltown via East Hills during peak hours only; however, in 1988 an all day half-hourly service was provided. Local (all stations) services generally ran every 15 minutes from East Hills.