it's 1966 and Main Line steam traction is coming to an end, some long distance trains are still steam hauled as shown in this view of south London's major termini Waterloo station.

the loco that slowly goes past giving great views of the massive machine is the former '145 Squadron' weighing in at 130 tons inclusive of tender, by this time most of the nameplates had been removed for safekeeping and or disposal. It had 6ft 2in driving wheels and a 280lbs psi boiler driving 3 pisons of 16 and 3/8 bore x 24 inches stroke. Originally when built they had air-smoothed casings which led to the nickname of 'Spam cans' among other epithets. The casings were eventually removed as they presented problems for fitter access and the lagging between the boiler and side sheets would often catch fire if soaked in oil which they often were. Here we see it with a full tender of coal (about 6 tons) so it's probably destined for the channel ports as evidenced by the inclusion of a Parcels/luggage wagon immediately behind the loco and in fromt of the coaches.