Having just arrived at West Drayton on 22 June 1991 with the 11:50 Slough to West Drayton Network SouthEast service, L406 (51341, 59493 & 51383) moves forward after reversing, in order to form the 12:15 West Drayton to Slough train. Note the red flag across the closed line in the background. I hope the driver remembered to change the red lights before he left the station!