|Number built:||110 4-car sets|
|Engine:||4 EE507 traction motors (750v DC third rail)|
|Power:||1, 000 hp (746 kW)|
|Formation:||Original : Driving Motor Brake Standard (DMBS)+Trailer Composite (TC)+
Trailer Standard (TS)+DMBS
Refurbished : Driving Motor Standard Open (DMBO)+
Trailer Brake Composite (TBC)+Trailer Standard Open Lavatory (TSOL)+DMSO
411/4 and /9 : DMSO+TBC+DMSO
The Class 411 fleet was given a mid-life update (and renamed the Class 411/5) in the early 1980s at BR Swindon, changes included removing asbestos and moving the guard's compartment from motor cars to one of the trailers. The trailers also received refurbished Commonwealth bogies from withdrawn loco-hauled coach stock and improved windows . Public address systems and Mark 3 style seats were also installed though some passengers complained that the latter were not as comfortable as the old seats!  Nineteen Class 411s were converted to 3-car sets (hence 3-CEP) with the loss of the TSO trailer for use on less busy routes, these were re-designated Class 411/9 . A small number were also fitted with improved high-speed bogies (Class 411/6). Some 4-BEPs were also converted into 4-CEPs by removing the buffer facilities.
The Class 411s survived into the privatisation era and served with the Connex and South West Trains franchises before finally being withdrawn in 2005  after 49 years service making them the longest serving Mark 1 based EMUs. A number of sets and odd-cars have been preserved.
|Preserved 1198 at Chinnor|
|Cab of 1198|
|7104 leaving Ashford in 1979, photo (c) Martin Addison|
 Colin J. Marsden, DMU and EMU Recognition Guide (Ian Allan, 2013), p. 312
 R.L. Vickers, DC Electric Trains and Locomotives in the British Isles (David & Charles, 1986), p. 79
 Brian Haresnape & Alec Swain, Third Rail DC Electric Multiple Units (Ian Allan, 1989), p. 46
 John Glover, "EMU Refurbishing", BR Diary 1978-1985 (Ian Allan, 1985), p. 31
 Marsden, Recognition Guide, p. 313
 4-car Express Units (4Cep and 4Bep) and Motor Luggage Vans (MLV), Southern Electric Group <http://www.southernelectric.org.uk/features/historical-features/brfleet_cep.html>
Photo of 7104 licensed for reuse under the Creative Commons Attribution-ShareAlike 2.0 Generic License.