55022 (L122) is deputising for the DMBS (51358) of Class 117 unit L420, as it approaches Culham on 27 May 1989 with the 2C68 18:10 Reading to Oxford Network SouthEast service. The two remaining Class 117 vehicles are 59510 & 51400. This use of a 'Bubble Car' to replace a vehicle removed from a three car set was quite common at the time.