The Class 423 was one of many classes of slam-door electric multiple unit ordered in the 1960s to replace aging EMUs dating from the era of the Southern Region, and began service alongside the Class 421 before the end of the decade. Class 423s, alongside the Class 411s and Class 421s, operated across all electrified routes on the Southern commuter network. The Class 423 was the most plentiful however of these three classes, with a total of 194 units built.

By sectorisation the slam door units of the 1950s and 1960s were becoming increasingly outdated compared to much more modern rolling stock, however as many of the units in service were only 20 years old Network SouthEast had no choice to retain the majority of them. Privatisation however saw the end of the slam door units, as South West Trains, Southern and SouthEastern had all ordered replacements for these units ready for their withdrawal by the end 2005. The very last Class 423 4VEP operated on Saturday 26th November 2005 between Brighton and London Victoria, with Class 421 3CIG units being the only units retained after 2005 to operate the South West Trains Lymington branch exlusively.

423417 is currently the most complete of any Southern region slam door EMU classes. 3417 was a former South West Trains unit, and was chosen prior to withdrawal to receive British Rail blue livery as it was the best condition of the original 20 fleet members. Initially it was preserved directly by South West Trains who retained it for shunting duties at Wimbledon, however nowadays it is preserved by the Bluebell Railway. It is currently at Strawberry Hill depot in West London however, where a skilled team of volunteers maintain the unit to a mainline standard.

The Bluebell Railway and the Southern Electric Traction Group have confirmed that 3417 ‘Gordon Pettitt’ will be attending ‘The Greatest Gathering’ in August.

(1) BR Blue Grey / L&SE Jaffa Cake Class 411 1198/2304 preserved on the Chinnor and Princes Risborough Railway. (2) BR Blue Grey DTCsoL 76875 (Ex Class 423 3545) preserved at Sheperdswell on the East Kent Railway.  (3) South West Trains DTC 76762 (Ex Class 421 1881) and MBSO 62364 (Ex Class 421 1499) at the East Kent Railway. (4) BR Blue Class 423 3417 at Horsted Keynes on the Bluebell Railway. (5) Connex South Central DTCL 76397 (Ex Class 423 3905) at the East Kent Railway.

Additional information on the Class 423 and SR EMUs

Blood and Custard - 4 VEP

https://www.bloodandcustard.com/BR-4VEP.html

Blood and Custard - 4 BIG & 4 CIG

https://www.bloodandcustard.com/BR-4CIG.html

Southern Electric Traction Group

https://www.setg.org.uk/