Probably the most famous Southern Railway electric multiple units have been the three 5-car 'Brighton Belle' sets - 5BEL. These units were built for the SR in 1932 by the Metropolitan-Cammell Carriage, Wagon a Finance Company, each vehicle being manufactured to Pullman standard and, when introduced, were the first all electric Pullman cars in the world. The sets were intended for a newly-scheduled fast service between Victoria and Brighton, dubbed 'The Southern Belle'. Although the sets were electric multiple units, they broke the previous design and closely followed Pullman Car Company stock, with inward opening passenger doors and traditional Pullman styling.
The formation of each five car train was; driving motor brake third, seating 48 passengers, a third class parlour car seating 56, two first class parlour cars, each seating 20 and another driving motor brake third, giving a total unit capacity for 48 first and 152 third class passengers.
One of the main criteria laid down when the vehicles were under construction was that they should be the finest units in service. Special attention, therefore, was given to passenger comfort and internal noise levels. Coach bodies were of all steel construction with floors insulated by cork. Between the inner panels of the side walls and the steel skin was a thick layer of 'insulwood'. When the trains emerged in the early 1930s they carried Pullman umber and cream livery and the Pullman Car Company's coat of arms on each vehicle. First class carriages were named after women, whilst third class cars carried numbers. The name 'Southern Belle’ was given to the services operated by BEL units from their introduction, but during 1934 the service was revised and the name 'Brighton Belle' applied.
Operation of BEL stock was usually confined to the Victoria to Brighton line, and usually two units ran together leaving the third as a spare. Sometimes units operated in multiple with PUL or PAN stock, particularly if a BEL unit was under repair.
In 1941, the three units were taken out of service and stored, but were always kept in operational condition. Unfortunately, one unit received war damage and was returned to the builders in 1946 for renovation. After the cessation of hostilities the stock recommenced service on the Brighton main line and continued until April 30, 1972 when their final run took place, and the Pullman service was discontinued from the Brighton line.
During the late-1960s, when most of the other Brighton main line stock was withdrawn, it was decided that there was still life left in the BEL stock and the three units passed through Eastleigh Works for a heavy overhaul, emerging in a BR blue/grey Pullman livery. Thankfully, the vehicles were not sold for scrap when withdrawn and a number are now preserved, or have been sold to private individuals who use them for refreshment purposes. When introduced the sets were numbered 2051 3, subsequently changing in 1937 to 3051-3.