Brighton Line Electrification

The London Brighton and South Coast Railway (LBSCR), one of three principal constituents of the Southern Railway, had envisaged electrifying the London-Brighton service by extending its 6.6kV 25Hz a.c. overhead system and using motorised luggage vans, similar to those actually built for its Coulsdon-Wallington suburban scheme, to haul existing rolling stock.

However the Southern Railway later decided to standardise on the d.c. third rail electrification system developed by the London and South Western Railway (LSWR).  When the Southern Railway Board authorised electrification of the Brighton main line in 1929 it decided to operate passenger services with multiple unit rolling stock rather than locomotives.

The first of the new fleets of main line stock to appear in regular service was the 4 Lav, intended primarily for stopping services on the Brighton main line.  Each unit comprised two driving motor third class cars flanking two trailer composites, one of which had a side corridor and a lavatory at each end - the designation "Lav" indicated that, unlike the suburban EMU fleet, these units included a coach with lavatory access.

Maunsell units

33 4 Lav units, numbered 1921-1953, were built between July 1931 and September 1932.  Their general structure and appearance was typical of the Maunsell/Warner "middle period", with steel panelled, hardwood framed bodies.  Door droplights were wood-framed with ventilators above.  Externally the bodysides were curved, except at the guard's van/cab end of the motor coach where they were flat.  The flattening corresponded with steam practice but whereas the flat sides of the steam coach guards'; vans incorporated a ducket (a projecting look-out for the guard) the 4 Lav units were the first Southern rolling stock to have periscope mirrors as standard equipment to provide the guard with a view of the lineside signals - a late change in the specification, perhaps?

Internally, the new units provided a high standard of comfort compared with contemporary suburban stock, with hammock-sprung seating, armrests in third class as well as first, and a good standard of finish.

The two motor coaches  had seven third class compartments, guards/luggage compartment and cab.  The non-corridor trailers were originally built with five first and four third class compartments but the declining demand for first class accommodation after the 1939-45 war resulted in successive deratings which eventually reduced the number of first class compartments in these cars to two.  The corridor trailers had three third and five first class compartments.

The specifications for the underframes, running gear and electrical equipment of the new units were similar to those of the 3-car suburban EMUs, with Metropolitan-Vickers electro-magnetic control gear mounted in cases on the rear bulkhead of the motorman's compartment and two MV339 (later EE339) traction motors driving the two axles of the leading bogie of each motor coach..  The Lav units could therefore operate in multiple with suburban fleets as well as with the later Nol, Bil and Hal units.  As with the suburban fleet, coaches were close-coupled within each unit.

1921-53 were renumbered 2921-53 at the beginning of 1937 as part of a general rationalisation of main line unit numbers.

The Bulleid units

Two additional 4 Lav units, 2954 and 2955, were ordered in 1939 and completed in 1940.  These had the same internal layout as the earlier type but, as was standard for suburban stock from 1937 onwards, were fitted with English Electric motors and underfloor-mounted electro-pneumatic control gear, backwards-compatible with the MV equipment of earlier units.

Bodywork styling, construction and interior finish were the same as the 1939 Hal units, the only difference in the motor coaches being that they had one unidirectional guard's periscope instead of the Hal units' two.  Motor coaches tared 44 tons, non-corridor composites 29 tons and corridor composites 30 tons.

In service

The 4 Lav units carried out the job for which they were built, earning revenue on semi-fast and stopping services on the main line to Brighton , throughout their 35 year working lives.  Only rarely did they operate over other routes.

Serious war damage affected only one unit, 2947, which was repaired and returned to service in due course.

Coach 10511 of unit 2926 was lost in the accident at South Croydon on 24^th October 1947 and was replaced by 10764 from disbanded 2 Hal unit 2646.

Coach 12001 of unit 2926 was badly damaged in a collision at Brighton on 19^th September 1961 and was subsequently cut up.  When the rest of the unit was repaired, 1945-vintage ten-compartment trailer third (second class by this time) no 10359 from withdrawn 1925 Sub. unit no 4338, was inserted and the unit became in effect, though not officially, 4 Nol when it returned to traffic in October 1962.  As part of this rehabilitation the former first class compartments of 11509 were reinstated.  Having acquired a Hal motor coach in 1947 following the South Croydon collision this unit now had a decidedly eclectic appearance.

Other Lav units involved in minor incidents included 2929 (Reigate 1957 and Victoria 1963); 2932 (New Cross Gate 1957); 2938 (Reigate 1957 and New Cross Gate 1967); 2944 (New Cross Gate 1960); 2943 (January 1967) and 2952 (1962).

Withdrawal

Towards the end of the fleet's working life, when the cost of repairs could not be justified and the condition of some vehicles' bodywork was giving concern, there were several reformations to keep as many units as possible operational.  Following an incident in January 1967 unit 2943 acquired a Bil. motor coach and in the same year 2932's motor coaches were replaced by a pair of all-steel 4 Sub coaches.

The 4 Lav units were withdrawn in 1968-9 though the Hal-type motor coaches lived on as de-icing units.