1. Description
    Standard units  8Vab unit  4Veg units  Vehicle numbering 

2. Final operations
    South Eastern Trains  South Central/Southern  South West Trains 

3. Further use

4. Accidents and incidents

5. Remaining unpreserved units/coaches

6. Preservation

7. Fleet details

8. Modelling

9. References
    Sources 

The British Rail Class 423 (or 4Vep (Vestibuled Electro-Pneumatic brake)) electrical multiple units were built by British Rail (BR) at York Works from 1967 to 1974, although the MBSOs and TSOs of the first 20, 7701-7720, were constructed at Derby Works. They feature 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 and Sussex, up to 2005 when they were finally replaced by Electrostar and Desiro units. The fleet had a lifespan of 38 years.

Description

Standard units

194 standard four-car units were built between 1967 and 1974, numbered 7701-7894. They were subsequently renumbered in the 1980s into the 30xx and 31xx series, in order to make numbers TOPS compliant. Between 1988 and 1990 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.

8Vab unit

In 1968, due to a shortage of suitable stock for the Bournemouth electrification scheme, BR formed an eight-carriage 8Vab 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 4-TC; 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 4Rep stock, but at least one of the original units was not reformed, as spare vehicles from the unit had replaced crash-damaged Vep vehicles in the meantime.

4Veg units

In 1978, 12 units, nos. 7788-7799, were fitted with extra luggage racks (by removing the squabs and backs from certain seats) and reclassified as Class 427 4Veg units. The units were renumbered into the range 7901-7912. 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 normally ran only with other 4-VEG units.

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 Vep units. The fleet of each franchise is described below.

South Eastern Trains

South Eastern Trains operated the largest fleet of 4Vep units. The franchise was originally operated as Connex South Eastern, which lost the franchise in 2003. The fleet contained several unusual units, included no. 3473, which contained a driving trailer with the compartments removed, and no. 3582, which contained former 4TC driving trailer 76275.

Many units survived into 2005 because of the closure of the Folkestone—Dover section of railway for tunnel refurbishment. This ended in September 2005. The final passenger service was operated on 7 October 2005, using units 3565, 3545 and 3568. Incidentally unit 3545 contained 62121, the first 4Vep MBSO built.

All the South Eastern Trains 4Vep units have now been withdrawn. One driving trailer from unit 3568, and another from 4Vep 3545, have been claimed by the National Railway Museum, and the former 4TC driving trailer from unit 3582 have been preserved.

South Central/Southern

The Network SouthCentral division inherited a fleet of 50 standard Class 423/1 units. The franchise was originally won by Connex South Central, which soon applied its yellow and white livery to the fleet. However, following poor levels of service, the franchise was transferred to South Central Trains in 2000, which was later renamed as Southern in 2004. Only one unit, no. 3514, was ever repainted in Southern's green livery.

In 1998-1999, whilst still under the control of Connex, 19 units were modified to operate inner suburban South London "Metro" services. The work involved removal of internal compartments and declassification of 1st class seating. The units were reclassified as Class 423/9 (or 4Vop) and renumbered in the range 3901-3919. Due to the lack of first class seating and toilets, these units were generally not used on long-distance services.

In 2003, with the general run-down of slam door trains, it was decided to reform some of the 4Vop units by swapping one driving trailer with that from a standard unit. The new hybrid units were reclassified as Class 423/8 (or 4Vip) and renumbered in the range 3813-3844. This was to give all units some 1st-class seating, thus making diagramming of units easier. But in the event only eight units were reformed, namely nos. 3813/14/21/22/41-44.

By 2004 Southern had started to introduce Class 377 "Electrostar" units into service. Although first introduced in 2002, this did not initially affect the Class 423 as the older 'Phase 1' Class 421 units were withdrawn first, due to their age and lower seating capacity. However, as more new units entered traffic, the first Class 423 units were withdrawn. Units selected for withdrawal were usually those with high mileage or in poor condition. By mid-2005 only a handful of units remained in traffic. The final diagrammed passenger service out of London was the 17:17 London Victoria to Eastbourne and Seaford on 19 August 2005, formed of units 3486 and 3535, plus 4Cig 1866. Six units were subsequently retained for emergency cover. Unit 3514 was used on the Sussex Slammer railtour on Saturday 19 November 2005. The following Saturday saw the final slam door trains on Southern, when units 3490, 3505 and 3535 formed the 09:19 Brighton to London Victoria and 11:06 London Victoria to Brighton services, following which all the units were withdrawn from service.

One complete 4Vip unit has been preserved, and two 4Vop units remained in departmental use until March 2013.

South West Trains

South West Trains (SWT) inherited the second-largest number of units, with an initial fleet size of 62 units. The entire fleet was composed of standard Class 423/1 units. Later, a further four units (nos. 3809-3812) were transferred from Connex South Eastern. These were also standard units, but were numbered in the 38xx series to denote they were leased from Porterbrook rather than HSBC Rail.

SWT quickly repainted its fleet of units into a new livery, based on the previous Network SouthEast (NSE) livery, but with the addition of an orange stripe and the absence of the grey band. All but four units (3415 and 3809-3811) were repainted. These four units were deliberately retained in NSE livery, meaning that in the final days of slam-door trains they attained "celebrity" status among rail enthusiasts.

In 2001 SWT placed an order for 785 new carriages with Siemens AG to allow it to replace its fleet of slam-door trains. To assist Siemens in the design of third rail units, 4Vep no. 3810 was transferred to a test site in Germany to undergo tests. Following its return to Britain it became popularly known as the "Great Escape".

South West Trains started to replace its slam-door fleet from early 2004, with the introduction of the first Class 444 and Class 450 Desiro units. Around this time SWT repainted one unit, no. 3417, into its original BR Blue livery to commemorate the final months in traffic of the slam-door fleet. This unit was chosen because it was one of the last to receive major works attention, and therefore had the longest life-expectancy. It was named Gordon Pettitt after a former manager of the Southern Region of British Railways.

In the final months of traffic several units, including the first-built, no. 3401, were reformed in order to allow the vehicles in the best condition to be retained in service. Withdrawals of units picked up pace, with several large culls of units, the last of which occurred in March 2005. Beyond this date only a handful of units remained in traffic, namely nos. 3401/17/81 3516/20/36/76 and 3811. The final normal passenger service was operated on 26 May 2005 from London Waterloo to Bournemouth, using 4Vep 3536 sandwiched between 4Cig units 1396 and 1398. Following withdrawal most units were rapidly towed away for scrap. The "celebrity" blue unit, no. 3417, has been since been sold to the Bluebell Railway.

Further use

Following withdrawal from normal service, several vehicles have seen further use in departmental service.

• 4Vop units 3905 and 3918 were converted into tractor units. They were used to haul Class 375 units to and from Ashford Works.
• MBSO 62138 (ex-unit 3567) was renumbered to 977981 and was used as a motor coach in the Hitachi V-Train no. 960201 during third-rail testing. It has since been scrapped.

Accidents and incidents

• On 26 January 1985, units 7754 and 7703 formed a train with 4CIG 7395 which was halted by a landslip at Popham, Hampshire and was run into by class 33 locomotive 33 104 due to the traincrew failing to protect the rear of the stranded train. Twelve people were injured. The Class 33 was written off.^[6]
• On 6 November 1985, unit 7724 collided with 4CIG unit 7390 at Copyhold Junction, near {{rws|Haywards Heath}}, West Sussex due to a lack of braking and poor rail adhesion. Forty people were injured.^[6]
• {{main|Clapham Junction rail crash}} On 12 December 1988, a train comprising units 3033, 3119 and 3005 formed the 07:18 {{rws|Basingstoke}} - Waterloo service which was run into by the 06:14 {{rws|Poole}} - Waterloo service, formed of 4REP unit 2003 and 4TC units 8027 and 8025 at {{rws|Clapham Junction}}. An empty stock working comprising units 3004 and 3425 running in the opposite direction on an adjacent line was struck by the derailed trains. Thirty-five people were killed, nearly 500 were injured.^[7][8]
• {{main|Purley rail crash}} On 4 March 1989, unit 4 March 1989, unit 3441 is run into by a passenger train comprising 4CIG units 1280 and 1295, which had overrun signals at {{rws|Purley}}, Surrey. Five people were killed and 88 were injured.^[9]
• On 1 August 1990, Class 119 diesel multiple unit L576 collided with a passenger train comprising 4VEP units 3508 & 3504, and 4CIG unit 1304 at {{rws|Reading}} due to overrunning signals. Forty people were injured.^[10]

Remaining unpreserved units/coaches

Preservation

So far two complete units (highlighted in table below) and two individual driving trailers have been preserved. In addition the former 4TC driving vehicle from set 3582 has been preserved.

The more high-profile unit preserved is the former South West Trains (SWT) "celebrity" unit painted in BR blue livery with painted aluminium window frames, number 3417. The unit was initially used on Wimbledon depot as a shunter, but with SWT needing to get it off its books it was sold to the Bluebell Railway for the nominal sum of £1. It was moved to Eastleigh Works for storage, after having been used initially as the centrepiece for the Bluebell in a ceremony at East Grinstead railway station to mark the commencement of work at the station site as part of the line's work on the northern extension. The unit returned to East Grinstead for further use and storage in September 2010. In late April, the unit sustained minor damage to its shoegear as it was being driven from sidings at Clapham Junction Yard print to movement under tow to the Swanage Railway. This resulted in the traction current being discharged in the yard whilst repairs were carried out. The unit was then moved back into the sidings and then dragged to Swanage the following day. The unit was for some time stabled in the open at Clapham Junction, having previously been stored in the shed at the yard. The unit was then moved to Ilford as part of a deal brokered by the unit's support group for a full repaint. After the completion of this body work restoration, the unit was transferred to Strawberry Hill in South West London where it remains, undergoing long-term restoration by volunteers from the Southern Electric Traction Group.

The second set, 3905 was turned into a tractor unit before being used as spares by the 5-Bel Trust to restore a 5-Bel Set, It was donated for preservation and was stored at the Dartmoor Railway. In 2016 the termination of lease by Dartmoor Railway meant the unit would leave the railway and find a new home at The East Kent Railway in Sheperdswell.

One other set was briefly preserved until 2010 when it was scrapped, 3822, was located at the Churnet Valley Railway and was partially restored. In 2008 half of the set was returned to as-built BR Blue and received internal repairs. The other half remained in "as withdrawn" Connex condition, and the set operated at several special events throughout that year.

There was an attempt to preserve unit 3810 (the unit that was briefly exported to Germany), but this failed and the unit was scrapped.

Fleet details

Modelling

Hornby produce the 4 VEP model in OO gauge. The model represents the main 2 variations;

1) Original units with the full brake area in the MBS, and;

2) Refurbished units (as undertaken from 1988 onwards) with a reduced brake compartment replaced with extra seating bays.

References

Sources

• {{cite book|title=Multiple Unit Pocket Book|series=British Railways Pocket Book No.2|edition=Summer/Autumn 1987|year=1987|first=Peter|last=Fox|publisher=Platform 5 Publishing Ltd.|isbn=0906579740|oclc=613347580|ref=harv}}
• {{cite book|title=Electric Multiple Units|series=British Railways Pocket Book No.4|first=Peter|last=Fox|publisher=Platform 5|edition=7th|year=1994|isbn=9781872524603|ref=harv}}
• {{cite book|title=British Railways Electric Multiple Units to 1975|first=Hugh|last=Longworth|publisher=Oxford Publishing Co.|year=2015|isbn=9780860936688|oclc=923205678|ref=harv}}

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