The British Rail Class 442 (5-WES) Wessex Electrics electric multiple unit passenger trains were introduced into service on the London Waterloo to Weymouth line in 1988 by Network SouthEast coinciding with the electrification of the western extreme of the line from Bournemouth. Twenty-four five-car units were built by British Rail Engineering Limited at its Derby Litchurch Lane Works. As part of the privatisation of British Rail, the Class 442s were sold to Angel Trains and leased to South West Trains when it took over operation of the route. Class 442s later appeared on Portsmouth line services. They were nicknamed 'Plastic Pigs'.