The SR then electrified the line from Three Bridges to Portsmouth via Horsham and the coastal route from West Worthing to Havant, with services over this route commencing in July 1938. For services from London Victoria to Portsmouth via Dorking over these lines, another 26 4-COR units (numbered 3130–3155) were built, together with 13 4-BUF units (4-car Buffet units, numbered 3073–3085).
