Turnaround times

[somebody]

I have noticed that the July 2007 Ferny Grove and Airport timetables both had 7 minute turnarounds, which helped clearing single track constraints.  I thought that the requirement for turnarounds as agreed with the union was 8 minutes for a 6 car train.  Back on those days, were the off peak services operated with 3 car trains to have faster turnarounds at these locations?

This is important particularly for the Airport, as you could then get in and out of the single track without needing to cross.