SR Class 4Sub

The Southern Railway (SR) gave the designation Sub to the wide variety of electric multiple units that were used on inner-suburban workings in the South London area. Originally these units were formed as three-car units, but in the 1940s, all surviving units were increased to four cars by the addition of an 'Augmentation' trailer. New four-car units were also built at this time, and these survived in passenger use until late 1983, by which time British Rail had allocated to them TOPS Class 405.

4SUB
405