Just after midday on Monday 03 August 2020, a Network Rail Test Train, running as 3Z52 (Derby 0738 hrs to Exeter Riverside), exits the short tunnel at Flax Bourton to the west of Bristol. Motive power was provided by Colas Rail Class 37 locos nos. 37219 &37610. I was fortunate with the light here. As I turned to get the going away shot the sun disappeared behind the cloud.