20227 & 20142 Sir John Betjeman pass Greatmoor (between Calvert and Quainton Road) on 29 April 2018 with the London Transport Museum 1Z33 10:22 Harrow-on-the-Hill to Quainton Road 'Class 20 Metropolitan' Railtour. Class 33 D6515 is bringing up the rear. Although this looks like a very rural location, and indeed can only be reached by a long walk, just off to the left of the picture is a huge new waste burning electricity generating facility.