Looks like a 12:01 WTT arrival forming a 12:04 WTT departure.St.Erth - St.Ives has several turnarounds at 1 min in the public timetable. For example, 11:48 SER-SIV arr 12:02 next working 12:03 SIV - SER Not sure what is shown in the working timetable.
Roy