The Southern Railway electrified its main lines to Portsmouth via Woking (the 'Portsmouth Direct') in 1937 and via Horsham (the 'Mid Sussex'), including the branch from Barnham to Bognor Regis, in 1938.

The express units built for these routes represented the last new EMU design of the Maunsell regime and were a radical departure from the Pul and Pan types.  Instead of the six-coach units, each self-sufficient for catering, that had been provided for Brighton and Eastbourne services, the new fleets comprised four-coach units with gangway connections from unit to unit.  Catering was provided from a single unit in each train, accessible from the other units in the formation.

Three sub-types were produced:

• 4 Cor: Trailer third and trailer composite marshalled between a pair of motor brake saloon thirds
• 4 Res: Trailer kitchen/diner third and trailer compartment/diner first marshalled between a pair of motor brake saloon thirds
• 4 Buf: Trailer buffet and trailer composite marshalled between a pair of motor brake saloon thirds

4 Cor units were built in two lots; 3101-3129 in 1937 for the Portsmouth Direct route and 3130-3155 in 1938 for Mid-Sussex route.  The 4 Res units for the Portsmouth Direct service were numbered 3054-3072 and appeared in the spring of 1937.  The 4 Buf units for the Victoria-Bognor Regis service were completed in May, June and July 1938.  Although the 4 Res and 4 Buf units generally remained on their original routes, the 4 Cor fleet quickly became common-user across the South Western and Central Divisions.

All the 4 Cor, 4 Res and 4 Buf coaches were built by the Southern Railway (bodied at Eastleigh on Lancing underframes), except for the 4 Res trailers which were built by contractors.  Overall styling reflected Maunsell's 'late' period, with glazed sliding ventilators above large, rectangular windows for each saloon seating bay similar to the Pan fleet.  Compartment trailer external doors had no ventilator above the droplight and single, rather than biparting, sliding doors between compartment and side corridor.

Unit ends were utilitarian in the extreme, with a central gangway separating the driver's window on one side and an illuminated display box for headcode stencils on the other.  Instead of the single control jumper and receptacle of the earler fleets, these units had a power jumper and control receptacle on one side and a control jumper and power receptacle on the other.

Owing to their one-eyed appearance and to their associations with Portsmouth (Pompey) these units were known to most railway staff and enthusiasts as 'Nelsons' or 'Pompey stock'.

By 1937 English Electric had won the contract to supply the Southern Railway with traction electrical equipment.  The design was, however similar to the equipment supplied by Metropolitan Vickers and BTH for the Pul, Pan and Bel units - presumably the Southern owned the intellectual property rights for these designs.

Whereas the Pul, Cit Pan and Bel units had two motor bogies on each motor coach, the Cor Res and Buf units had only one, of the equalising beam type.  This reduced the installed power for a 12-coach formation from 3,600hp for the earlier fleets to 2,700hp for the later types, and reduced driven axles from 16 to 12.  At first sight this reduction in available power is surprising, given the long, steep climbs of the Portsmouth Direct route.  However, the speed of express services between Guildford and Fratton was constrained by that of the half-hourly all-stations service so greater power would not have been of much commercial value.  Drivers of late-running trains sometimes compensated for less-than-sparkling uphill performance with riotous speed on the descents.  Passage over the crossings outside Petersfield station in either direction could be particularly lively as motormen made best use of the dip to take a run at the inclines that lay ahead.

Motor coaches

The internal layout of the motor coaches was cab, guards van, vestibule, saloons of 3½ bays and 3 bays separated by a partition, vestibule.  The coach had communicating doors and gangways throughout and the driving compartment had a movable partition to screen the driving position and controls when the vehicle was coupled to another unit and the passenger gangway was in use.

Trailer coaches

The trailer composites had five first- and three third-class compartments and the trailer thirds had 8 compartments and a coupé (half-compartment).  Both had a side corridor and a lavatory at each end.

Dining cars

The trailer compartment/diner firsts for the 4 Res units were built by Metropolitan Cammell and had 42 seats in five compartments and a dining saloon with 12 seats.  There was a lavatory at each end of the compartment section.

The kitchen/diner thirds were built by Birmingham Railway Carriage and Wagon Company (BRCW) and had a kitchen and a dining saloon with 36 seats arranged in 4-seat bays either side of a central passageway.

Buffet cars

The buffet cars for the 4 Buf units were the last vehicles of the contract to come off the production line, having been completely redesigned internally just as they were about to be built.

The redesigned interiors reflected the advanced styling policy which the Southern adopted about this time, not only for rolling stock but for station buildings such as those on the Chessington branch.  Of the Chief Mechanical Engineers of the time, Oliver Bullied (who succeeded Robert Maunsell as CME of the Southern in 1937) was particularly conscious of modern decorative art and lost no time in moving away from the traditional styling of the Maunsell era.  The result was a complete departure from varnished hardwood finishes  - the new cars had an Art Deco interior with Rexine finishes in pale pastel shades and a striking royal blue Wilton carpet with gold diagonal bars.

The Bognor Buffets, as they were known, had a small kitchen, a bar section with ten stools and a saloon section with four four-seater window tables, scalloped in front of each chair.  Beyond the saloon was a cross-vestibule and then a lavatory.

Externally the buffet cars were painted in the Southern's new malachite green livery, contrasting with the olive green of the other cars, giving the 4 Buf units something of a piebald look.

In service

Buffet facilities were taken out of use from 27 May 1942 and re-opened on 7 January 1946.  The cars were removed from their units and stored on the Crystal Palace (High Level) branch, which was closed for the duration.

The Cor Res and Buf units suffered severely during the 1939-45 war.  In particular part of 3132 was marooned on a severed portion of Portsmouth Harbour station after the station was damaged by fire, and several units suffered extensive air-raid damage when Fratton depot was hit and when a V1 'doodle-bug' flying bomb fell at Wimbledon Park in June 1944.  In all, 11 motor coaches and 14 trailers were written off as war losses and undamaged and repairable cars were reformed during the war, resulting in a high proportion of 'odd' formations.

Between July and November 1946 the total number of coaches was made up to the original strength by the construction of 25 new coaches to the original designs.  Perhaps because the Southern was already finding that the original provision of full restaurant car facilities was not required on the 90-minute Waterloo-Portsmouth run, three kitchen cars lost to war damage were not replaced.  Instead 4 Res units 3058/60/63 were struck off and three additional 4-Cor units, 3156/57/58, were formed.

Unit 3152 was derailed at Merstham on the Quarry line on 27 June 1949.

As the 7.50 p.m. service from Waterloo to Portsmouth Harbour was detained by signals outside Woking station on 23^rd December 1955 it was run into by the 7.54 p.m. steam-hauled service from Waterloo to Basingstoke, hauled by an N15X 'Remembrance' class 4-6-0.  The driver of the steam train, which had passed Maybury Down through Intermediate at danger, had seen the tail light of the electric train ahead and had reduced speed to walking pace on impact.  Nobody was seriously hurt but the rear car of unit 3147 was severely damaged.

The kitchen car of Res unit 3072 was badly damaged by fire in June 1954.  The three undamaged coaches ran for some time as a three-coach unit, mainly on the Hounslow Loop whilst it was completely rebuilt as a buffet car, with an interior not unlike the contemporary buffet refits of Maunsell locomotive-hauled former restaurant cars.  The unit was returned to service in February 1956.

For some years it was rumoured that the whole of the Res fleet was to be converted to buffet operation.  Eventually, in 1961, three kitchen diners, from 3056/65/68 were sent to Eastleigh for conversion to the then latest idea in catering vehicles - griddle cars serving hot snacks.  The conversion involved the removal of the whole of the interior and much of the exterior and resulted in a combination of Maunsell styling and BR fittings.  The diner firsts in these units were also slightly modified, from 12 chairs at 4 tables to 4 chairs at 2 tables plus 8 loose chairs.  The three units were classified 4 Gri though they retained their unit numbers in the Res series until they were renumbered 3086/87/88 in December 1963.

From about March 1962 all units were progressively fitted roller blind headcode equipment, driver-to-guard loudaphones and bells and a second heater in the guard's compartment.  The Cor, Res and Gri units were done first; the Buf units were not dealt with until the summer and autumn of 1964.

On the foggy morning of 8^th February 1963 3134, operating a Coastway service, collided with the rear of 3139 at Drayton, near Chichester.  The accident, primarily caused by signalman error, caused the leading car of unit 3139 to override the underframe of the rear car of 3134, demolishing the cab and guard's van.  Luckily nobody was badly hurt in the relatively low speed collision, the driver of 3134 having bailed out.

Early in 1964, CEP/BEP stock displaced the Cor/Buf fleet from the Victoria-Bognor/Portsmouth expresses.  The Buf units joined 3072 and the three 4-Gri units on the South Western Division, displacing the remaining Res units from Waterloo-Guildford-Portsmouth services.

Cor units displaced from the Victoria-Bognor/Portsmouth route largely replaced Bil./Hal. stock on many of the Coastway services between Portsmouth and Brighton; presumably their corridors made revenue collection easier on this route with its many closely-spaced unstaffed halts.

4 Pul and 4 Cor(N)

The kitchen cars of the redundant Res units were withdrawn and the units transferred to the Brighton main line as a stopgap to supplement the ageing Pul and Pan units pending delivery of the new CIG/BIG fleet.  Five 6 Pul units were disbanded and their Pullman cars, Clara, Gwladys, Elinor, Enid and Ethel were marshalled into units 3054, 3055, 3057, 3059 and 3061 respectively.  The first four retained their original numbers; 3061 was renumbered 3056.  Pullman car 'Alice' replaced 'Enid' in 3059 from October 1964 and 'Lorna' replaced 'Elinor' in 3057 from February 1966.

6 Pan units 3027, 3031 and 3033 were also disbanded and some of their trailer seconds were marshalled into the remainder of the former Res fleet to form seven 4 Cor(N) units.  Unit 3062 was renumbered 3065 and 3064 was renumbered 3068 in order to make up a consecutive series 3065-71, otherwise units retained their original numbers despite the convention that pre-war express units in the 30xx series had catering facilities.  Whilst operating on the Brighton main line, a 4 Pul unit would normally be paired with one or two 4 Cor or 4 Cor(N) units.

Trailer set 601

In June 1965 three 'Cor' vehicles, 10041 and 11229 from unit 3070 and 11154 from 3056, together with various cars from 6 Pul units, were used to form a 6-car push-pull trailer set 601.

Additional 4 Cor units

By 1965-6 the 4-Pul and 4-Cor(N) units were becoming spare as they and the remaining Pul/Pan units were displaced from Brighton/Eastbourne services by new deliveries of CIG/BIG stock.  They were again re-formed to make up ten additional 4 Cor units with conventional formations, using the best of the trailers from withdrawn Pul/Pan units:

In 1965 BR launched its new corporate livery based on Monastral Blue.  Initially, the policy was not to paint older fleets in the new livery and a few units of the Cor family, then receiving major overhauls at Eastleigh, were instead turned out in the dark green that had previously been applied to non-Southern Region diesel multiple units.  This colour, somewhat similar to the Southern's pre-war Olive Green, well suited the rather severe external image of the units.  However, by the following year, overhauled units were being turned out in overall blue livery, a colour that seemed only to emphasise the age of the fleet.

Early in the 1970s the Waterloo-Portsmouth express service, which had been operated almost exclusively by rolling stock of the Cor family for some 35 years, was converted to CIG operation.  BR had in the meantime called a halt to overhauls of pre-war Southern EMUs so, as many of the Cor units were in good condition, they replaced the dwindling fleet of Bil. and Hal. stock on the Waterloo-Reading/Aldershot route as well as on the remaining Bil./Hal.-operated Coastway services.

Wholesale withdrawals of the remaining Cor units took place during 1971-72 and many reformations were made to keep the remaining units in service.  The era of BR operation finally closed with a railtour in December 1972, operated by units 3116, 3123 and 3142.

Preservation

It was not quite the end.  The National Railway Museum acquired motor brake second 11179 from unit 3131 and Bulleid-styled trailer buffet 12529 from unit 3084.  The former today forms part of the NRM collection at York but the latter, tragically, was extensively damaged by fire during restoration in October 1978 and has since been broken up.

The Southern Electric Group purchased unit 3142 on withdrawal and, in keeping with the tradition of extensive reformations throughout the life of the fleet, replaced 3142's trailer composite with 11825 from unit 3135 as this vehicle was in better condition than 3142's original 11832.

Brian Juniper purchased motor brake second 11187 from unit 3135 and this vehicle is currently being restored at the London Transport Museum, Acton.

More details of 3142 and the preservation of other Southern Electric stock can be found in our preservation section.