Apart from the pioneer South London units (See the pages on 2SL and 2Wim units) two designs of electric units were inherited by the Southern Railway
from the London Brighton and South Coast Railway which were to be absorbed into the general suburban fleet.
Following the success of the "Elevated Electric" scheme, the LBSCR embarked on further extensions the their 6 700 volt system and opened further lines from Victoria and London Bridge to Crystal Palace via Streatham Hill on the 1st of June 1911 and from Battersea Park to Crystal Palace Low Level and on to Norwood Junction, with the Peckham Rye - Dulwich - West Norwood line which were brought into use in 1912.
The new trains for these services were made up of thirty-four motor brake third class coaches and seventy driving trailer composites. The Crystal Palace tunnel was particularly narrow and as a result this stock was only 8ft 0ins wide. The trains were classified "CP" and, although the formation of trains varied, generally, but by no means exclusively, they consisted of a driving trailer either side of one of the motor brake thirds with two such configurations coupled together at the rush hour. Building of the new units was split between the Metropolitan Carriage and Wagon Co who built the motor coaches and 34 of the driving trailers and the LBSCR's coach works at Lancing in Sussex which built the remaining 36 trailers.
|Motor coach built for the LBSCR for their overhead electrification to Crystal Palace in 1911 - 12
photograph: Metropolitan Carriage & Wagon Co Ltd.
|A Crystal Palace unit of 1911 in typical formation passing Wandsworth Common on its way to Victoria in 1928.
photograph:Ian Allen/H C Casserley
Since most of the electrical equipment originated from AEG in Germany further extensions to the overhead system were
brought to an abrupt halt by by the First World War.
Nevertheless in the run up to the grouping in 1922 it was agreed by the constituent companies that the overhead system should be
extended. As a result even before the grouping, further extensions were put in hand to the overhead system from Balham
through East Croydon to Coulsdon North and also from Norwood Junction through West Croydon to Wallington and Sutton.
These were completed in 1925.
The stock for these sections was built after the grouping mainly at Lancing but with some coming from the former LSWR works at Eastleigh and some from the Metropolitan Carriage and Wagon Company. It consisted of sixty driving trailers and twenty intermediate trailers. Traction power was provided by twenty-one driving motor vans which were generally referred to as "milk vans". A 250hp traction motor drove each axle of both bogies of the motor van, they had a cab at each end and in addition they also had the guard's brake and luggage space. With a view to conforming to the current European standard the "milk vans" were designed to allow them to be converted to 11 000 volts.
Varying numbers of trailers and driving trailers were coupled to either end of the motor van to make up trains of the required length. This was known as the "CW" stock.
|A four car train complete with electric bogie power van at Coulsdon North in July 1928
photograph: O J Morris
|One of the bogie power vans - commonly referred to as "Milk Vans" - used on the Coulsdon North and Sutton electrification.
photograph: British Railways.
The management of the new Southern Railway, however, was largely drawn from the LSWR and the technical team were
mainly SECR men. Herbert Jones of the LSWR became the company's Chief Electrical Engineer with Alfred Raworth, who
had been with the LSWR before moving to the SECR in 1918, as his assistant. Richard Maunsell, the Chief Mechanical
Engineer, had been with the SECR since 1913. As a result not only was there not a lot of commitment to anything
originating from the LBSCR but both the Chief Electrical Engineer and his assistant were "third rail men" anyway
With the transformers and rectifiers being carried in the trains rather than sited in substations beside the track, it was not a surprise that the maintenance costs of the AC rolling stock were far in excess of the DC. With Sir Phillip Dawson still only being retained as a consultant by the LBSCR, his final report which had been prepared in 1921 for the Ministry of Transport's investigation and which eloquently put the case for the overhead system, had rather fallen on deaf ears. Clearly Sir Herbert Walker was sticking rigidly to the original decision of the LSWR that the third rail was more suitable for their - and consequently the Southern's - purpose. However it was not until October 1925 that the SR's board decided that all future electrification would be using the 600 Volt DC system. As a final nail in its coffin, in July 1926 it was further decided that the whole of the AC overhead system should be converted to the DC conductor rail system.
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This page was last updated 10 February 2013