55020 (121020) approaches Little Kimble on 21 March 2017 with the 2P16 07:47 Aylesbury to Princes Risborough Chiltern Railways service. At 56 years 6 months old, this and its slightly younger classmate 55034 are far and away the oldest multiple unit on the national network. However, all good things come to and end, and May 2017 will see these last two survivors withdrawn.