It was clear that BR(SR) M.N. Class 8P 4-6-2 35018 BRITISH INDIA LINE was working hard but receiving assistance from diesel electric 47 245 at the rear as they climbed the 1 in 50 towards the Bincombe Tunnels on 9th July 2021. Does that cloud of white steam above the back of the train indicate a momentary slip by the pacific?