"(Bulleid Pacifics) were wayward, difficult, brilliant, fascinating" R.H.N Hardy
The former Southern Railway was one of the pre-Nationalisation 'Big Four' of independent railway companies who preceded the former British Rail (along with the Great Western Railway, London, Midland and Scottish Railway and London And North Eastern Railway after the grouping of many smaller companies in 1923).
It decided, with the co-operation of the Air Ministry, to name 40 of its Bulleid light pacifics (i.e. a 4-6-2 wheel arrangement), originally introduced May 1945, after famous airfields, aircraft, squadrons and others associated with the Battle of Britain, as a tribute to the part they played in defeating the Luftwaffe, fighting, for the most part, over territory served by the Southern Railway.
After considerable correspondence and consideration, and rejection, of various names, names were allocated in a rather random way, being taken from Fighter Command's Order of Battle for No. 11 Group for 3rd November 1940 (The end of the Battle) with the occasional re-naming along the way.
Following introduction in 1946, they operated throughout the area covered by the Southern Railway, from the London terminals at Waterloo (London's last steam terminus in 1967) for the West Country and south coast, and the Kent coast expresses from Victoria, Charing Cross (to Ramsgate) and Cannon Street.
Since at the time of ordering they were destined for use away from the West of England already covered by the preceding 48 West Country pacifics, a different sequence of names was introduced, actually for 44 of the 110 locos eventually built. Construction of the West Country/Battle of Britain class continued after nationalisation, until January 1951.
Other than the nameplates and oval plaques with own badge or RAF insignia, the 'West Countries' and 'Battle of Britain's' were virtually identical, with their distinctive 'air-smoothed' boiler casing (hence their nickname 'spamcans' or 'streaks') and Bulleid-Firth-Brown 'Boxpox' driving wheels. Their chain-driven valve-gear in its oil bath between the frames could fail, and the oil proved to be a fire hazard on occasions when leaks reached the hot boiler region!
The 'Battle of Britain's' however did have minor modifications to cab and tender contours to enable them to work through the restricted tunnels of the Tonbridge - Hastings Line (which they never actually did on a regular basis). They were designed by the charming but persistent and controversial Chief Mechanical Engineer of the Southern Railway, Oliver Vaughn Snell Bulleid; all but six were built at Brighton locomotive works, the others at Eastleigh.