SR Schools 4-4-0 No 30922 Marlborough with a down Ashford line train approaching Tonbridge on 5 February 1960. Note the insulators in place for the third rail.
Robert Waterman says "Judging by 3 coach set 546 followed by a number of parcels vans, this is likely the 11.46am Charing Cross -Ashford".

Photo: D.M.C. Hepburne-Scott / Rail Archive Stephenson