Standard units

The standard units contained passenger seating only, and formed the backbone of the new fleet. 111 units were built in several batches, initially numbered in the range 7101-7211. Units 7101-7104 were the prototype units, and were followed by 'Phase 1' units (7105-7153) and subsequently 'Phase 2' units (7154-7211).

Units were formed of two outer driving motors cars with 2nd class (later Standard Class) seating in open saloons, sandwiching two intermediate trailer cars – one a corridor second and the other a First/Second corridor composite.^[2]

4 BEP units

The 4 BEP units were similar to the standard units, but contained a buffet car in place of the second class open trailer. The buffet trailer had a dining room, a large kitchen pantry, and a buffet counter with some seats.^[2]

22 units were built, initially numbered in the range 7001-7022. The first two units (7001-7002) were prototypes, and were followed by 'Phase 1' units (7003-7012) and 'Phase 2' (7013-7022).

The 4 BEP fleet were classified as Class 410 by British Rail under the new computer numbering system introduced in 1968.

4 TEP units

Between 1983 and 1986, several 4 Big units required extensive refurbishment. To cover their workings, four temporary 4 TEP units were created, formed of three carriages from a refurbished CEP unit, with an unrefurbished buffet car from a BEP unit. The units were renumbered in the range 2701–2704. They were based at Brighton depot and operated mostly on the London to Hastings line. The units were disbanded by 1986, once the refurbishment programme was complete, and were reformed as standard 4 CEP units. The unrefurbished buffet carriages were scrapped.^[4]

Unit formation are given below:

Connex South Central

The South Central (SC) division, operated as Connex South Central, briefly operated 4 CEP units in the period 1995–1998. Three standard units were converted to Class 411/6 by fitting them with high-speed Mk.6 motor bogies. These units were renumbered into the series 1697–1699. They were chiefly employed on London Bridge to Brighton express services. However, as the units were non-standard in the SC fleet, they were withdrawn and transferred to South West Trains.

South Eastern Trains

The South Eastern (SE) division inherited the largest fleet of 4 CEP units. The franchise was originally operated by Connex South Eastern, but after Connex lost the franchise it became South Eastern Trains. In 1996, when the franchise was awarded, a fleet of 85 standard units were in traffic. Many of these were quickly withdrawn from traffic, or transferred to the SW division. In early 1999, five units were converted to Class 411/9 3CEP units, with the removal of the second class open trailer. These removed trailers had not had so much work carried out on them at the time of refurbishment (as they were basically unchanged apart from cosmetic appearance and installation of hopper windows) and many had become severely corroded. This was necessary, as some stations could only accommodate 11 carriages. A further 13 units were later converted. The 3 CEP units were renumbered into the series 1101–1118.

The Connex fleet contained two 'celebrity' units. The first, no. 1592, was repainted by staff at Ramsgate depot into its original Green livery, to commemorate the final months in traffic for these units. The second, no. 1602, was the only 4 CEP unit repainted into Connex livery, after it received derailment damage outside London Bridge station, and had to be repaired at Eastleigh works. Both of these units were popular with railtours and excursion trains.

Withdrawal of units started in 1999, after they were replaced by new Class 375 'Electrostar' units. The original aim was to totally replace the 4 CEP fleet by 2000. However, poor reliability of the new units saw the 4 CEP's retained beyond this date. By the end of 2002, the fleet was again being reduced, with many standard units being sent to Immingham for scrap. The 3 CEP units were all withdrawn by March 2003, as units in traffic beyond this date had to be fitted with TPWS equipment. In the event, only seven units, nos. 1562, 1590, 1592, 1593, 1594, 1602 and 1615 were retained.

By the beginning of 2004, the seven units were withdrawn as they were due overhaul. They were replaced with units cascaded from South West Trains, which included the three Class 411/6 units. However, these units were themselves slowly retired, and it was expected the final units would have been withdrawn from service before the end of 2004. However, the Class 411/6 units were eventually withdrawn in July 2005, following the introduction of refurbished Class 465/9 "Networkers". Units 1697 and 1699 were sent for scrap, but 1698 was retained for working railtours. Due to a unit shortage It was later reinstated in August 2005, and remained in traffic until late September. It was one of three units to work a Ramsgate to Weymouth railtour, the others being 4 Cig 1866 and 4Vep 3545. Following this, it was quickly despatched for scrap.

South West Trains

The South West (SW) division franchise was won by the Stagecoach Group and was operated as South West Trains (SWT). SWT did not inherit any standard 4 CEP units, but it did operate the seven 4 BEP units. However, in 1996, a shortage of trains led to SWT hiring two sets (nos. 1568 and 1589) on a short-term lease. These units were quickly followed by more, until by 1998, SWT had a fleet of 29 standard 4 CEP units. These were gradually overhauled, and were employed on a range of duties, including services to Portsmouth, Reading, Southampton, Bournemouth and Weymouth. Additionally, units commonly worked services on the Lymington branch.

The fleet stayed reasonably static until 2002, when SWT reformed several sets. The buffet cars from the 4 BEP units were inserted into seven standard units, which were renumbered 2321–2327 (reclassified as Class 412/2). The displaced carriages were inserted into the 4 BEP units, which were renumbered 2311–2317 (reclassified as Class 412/1). The reason behind this was that the 4 BEP units had faster acceleration, and the buffet cars were no longer used. Therefore, the reformations allowed a higher seating capacity in the faster units.

By 2003, SWT had ordered new trains, to replace all its slam door trains. These were designated Class 444 for express trains and Class 450 for suburban trains. The first units to be replaced were the units in the 232x series, which were due for early withdrawal. Of the seven sets, one, set no. 2323, was withdrawn in 2002 due to fire damage, but was later converted back to a standard unit. Another, set no. 2326, was reduced to a 3 CEP, for operating the "Lymington Flyer" service on the Lymington branch, and was renumbered 1199. The remaining five units lasted until December 2003, when they were withdrawn. One, set no. 2325 was preserved, whilst the rest were scrapped.

The standard units lasted until early 2004, when they were either withdrawn and scrapped, or transferred to South Eastern Trains. One of the 4 BEP units, no. 2314, was converted into a 3CEP to replace no. 1199, and was renumbered 1198. Of the remaining six 4 BEP units, four were withdrawn in October 2004, leaving just two units remaining in traffic into 2005. The 3 CEP unit, no. 1198, was withdrawn at the end of December 2004, and was preserved by the EMU Preservation Society on the Dartmoor Railway before moving in 2008 to the Pontypool and Blaenavon Railway and then in 2013 to the Chinnor and Princes Risborough Railway. A replacement came in the form of 3Cig unit no. 1499. The final two 4 BEP units 2311 and 2315, soldiered on in traffic until withdrawal in March 2005. They were both later preserved at the Eden Valley Railway as 4CEPs.