This photo is a shot of a ‘push and pull’ train leaving Havant in the late 1940s or early 1950s.
On a normal push ’n’ pull there were two coaches and a loco. The driver sat in the carriage driving compartment and drove the train like a conventional electric. His fireman was on the footplate firing the engine.
When it reversed in the opposite direction the driver joined his fireman on the footplate of the loco and off they would go as a normal steam-hauled train.
Here there were two sets of rolling stock, I guess for a rail tour for enthusiasts.
It might be heading for Midhurst via Chichester. There was no run-round facility at Chichester so all the driver had to do was change ends at Chichester before setting off back towards Fishbourne and turning right at the junction for the Midhurst.