The British Rail Class 423 (4 VEP), electric multiple unit passenger trains were mostly built by British Rail (BR) at York Works from 1967 to 1974, although the MBSOs and TSOs of the first 20, 7701-7720, were built at Derby Works. They have manually opening doors next to every seating row and were the last coaching stock built in this pattern for BR. They were mostly found working outer-suburban services in South London and rural services in Kent, Sussex and Hampshire, up to 2005 when they were finally replaced by Electrostar and Desiro units. The fleet had a working life of 38 years.
Description
Standard units
Ordered in 1965, 194 standard four-car 4 VEP units were built between 1967 and 1974, numbered 7701-7894; subsequently becoming class 423 under TOPS. They were subsequently renumbered in the 1980s into the 30xx and 31xx series in order to make numbers TOPS compliant. Between 1988 and 1995 the units were internally facelifted. The work involved fitting fluorescent lighting and public address equipment, and also rebuilding the MBS (motor brake second) vehicles with an additional two bays of seating in space formerly used for luggage. On refurbishment only the first 20 units were renumbered in order, in the 34xx series. All other units were renumbered from 3421 onwards, in the order they were refurbished. All units ended up swapping motor vehicles on refurbishment - the additional work on these cars made the work take longer than that carried out on trailer vehicles.
8 VAB unit
In 1968, due to a shortage of suitable stock for the Bournemouth electrification scheme, BR formed an eight-carriage 8 VAB unit, no. 8001. The unit was formed of carriages from three standard sets, nos. 7739/41/42, plus a conventional locomotive-hauled buffet carriage. Three MBSOs were required within the make-up as the standard 'TRB' was not through-wired for traction power distribution. In view of this the two MBSOs in the five-car portion had collector shoes fitted to one bogie on each. The unit worked on occasions with a 4TC; this usually had a Class 33 attached to provide ETH and train lighting in the TC unit, as the 8 VAB was not fitted with ETH jumper cables on the unit ends. Its normal running formation was with another 4 VEP to make a 12-car set. The 'TRB' vehicle retained its gas-powered appliances so, unlike 4 REP buffet cars, was able to provide hot food and beverages while on diversions away from third-rail areas. Adjacent MBSO 62203 had most of its doors locked out of use and tables fitted across them for the service of meals on a 2-and-2 basis (across seats intended for five persons normally); this vehicle also had most of its luggage racks removed. The unit was later reclassified as Class 480 following the introduction of TOPS.
The numbering of individual vehicles are shown in the table below.
The unit was disbanded in 1974, following deliveries of 4 REP stock, but one of the original units, no. 7739, was not reformed, as spare vehicles from the unit had replaced crash-damaged VEP vehicles in the meantime.
4 VEG units
In 1978 12 units, nos. 7788-7799, were fitted with extra luggage racks by removing the squabs and cushions from certain seats and reclassified as Class 427 4 VEG units. The units were renumbered into the range 7901-7912 in the same sequence. These units were dedicated to the Gatwick Express services from London Victoria to Gatwick Airport. Externally these units were marked by an orange/yellow (dayglo) coloured band at cantrail level with lettering 'London-Gatwick express service'. They were used on Victoria to Bognor Regis services attached at the rear from Victoria and detached at Gatwick Airport so that airline passengers did not have to rush to get off the train. The unit then attached to the front of an Up Bognor Regis service back to Victoria.
In 1984 they were replaced on this service by Class 73 electro-diesel locomotives operating in push-pull with Class 488 coaching sets and Class 489 luggage vans. The twelve units were then converted back to standard sets, and regained their original unit numbers.
Vehicle numbering
The numbering of individual vehicles and details of when units were built are shown in the table below.
Final operations
Following the privatisation of British Rail the three southern train operators all inherited large fleets of 4 VEP units. A franchise commitment of all operators was to replace all of the units, along with all other Mark 1 rolling stock, by the end of 2005, as the units did not meet modern health and safety requirements. The fleet of each franchise is described below.