Bridges. Electrification The line was electrified using the (750 V DC third rail) system by the Southern Railway in 1938 as part of the proposals to electrify the lines from London to Portsmouth. This originally only covered the section from Horsham to Littlehampton and Barnham, as the main line was the line through Dorking and Sutton, as opposed to the line to Three Bridges, but plans were extended to electrify the "branch" as well in the same year. Electric services were provided by electric multiple units. For most of the rest of the twentieth century, an hourly express service was provided which joined/divided at Barnham, with 4 or 8 coaches continuing to Bognor and 4 to Portsmouth Harbour. This called at Arundel, Pulborough and latterly Billingshurst, going via Sutton and Dorking. An all-stations stopping service also ran hourly via Crawley to Bognor Regis, usually via Littlehampton. Later work Two bridges on the line, The Black Rabbit Bridge (just north of Arundel) and the Peppering Bridge (a few hundred yards further on) were replaced during the August Bank Holiday weekend of 2009. The line was completely closed to traffic during these major engineering works and a replacement bus service served stations between Arundel and Pulborough. As the two-week Arundel Festival was drawing to a close over the weekend, Southern maintained a service into the station from the West Coastway Line from Bognor Regis via Barnham and Ford, and a reversal at Littlehampton. Services There are currently four trains per hour in each direction over the route off-peak, made up of twin portions from two trains per hour from London Victoria. This is the most frequent service on the route since the late 1970s. Down-line services: Both divide at Horsham, the train on the hour has a front portion which is fast to Barnham then onto Portsmouth Harbour. The rear portion is semi-fast to Bognor Regis (not calling at Christ's Hospital and Amberley Stations). The 30-minutes-past train's front portion again runs fast to Barnham then is semi-fast to Southampton Central. The rear section calls all stations to Bognor Regis. Up-line service: Again two trains an hour, both services attach at Horsham. The Bognor Regis section always arrives first unless there is disruption and then a section from either Portsmouth Harbour or Southampton Central arrives. Once the train has attached it runs semi fast to London Victoria via the Horsham Branch Line (Horsham