The British Rail Class 411 (or 4-CEP) electric multiple units were built at Eastleigh works from 1956–63 for the newly electrified main lines in Kent. These units were constructed using a standard Mk1 design and based on the general philosophy of the Southern Railway’s main line 4 -COR design of 1937. Variants of the class 411 design included the class 410 and class 412 4 BEP units, which contained a buffet car in place of a standard trailer. They were later used on services in Sussex and Hampshire. Following the privatisation of British Rail in 1995, the units were used on Connex South Central, Connex South Eastern and South West Trains franchises. They were ultimately replaced by Juniper and Electrostar units during the industry’s drive to eliminate ‘slam-door’ rolling stock for reasons of safety and modernisation. The fleet's lifespan was 49 years; these units are the longest-lived BR Mark 1 EMUs.