The British Rail Class 321 are electric multiple unit (EMU) passenger trains built by British Rail Engineering Limited's Holgate Road carriage works in three batches between 1988 and 1991. The class uses alternating current (AC) overhead electrification. The design was successful and led to the development of the similar Class 320 and Class 322. Today the class is operated by Greater Anglia. Some have been converted to Class 320 and are operated by ScotRail. Description Three sub-classes were built. The first two were built for the Network SouthEast sector for operation on services from London Liverpool Street and London Euston, while the third was built for Regional Railways for use on West Yorkshire Passenger Transport Executive services from Leeds. As part of the privatisation of British Rail, ownership of the class passed from British Rail to the Eversholt Rail Group in April 1994. Each unit consists of four carriages: (DTC-PMS-TS-DTS) all units have a maximum speed of . They have been modified by the different rail companies which use them. The modifications include new seats, paintwork, lighting and passenger information systems. The trains have been nicknamed "Dusty Bins" by some enthusiasts, after the TV game show "3-2-1" which featured a mascot called "Dusty Bin". Class 321/3 In September 1987, Network SouthEast ordered 46 321/3 units for use on services from London Liverpool Street to Cambridge and Southend Victoria. The first was unveiled on 15 September 1988. A further 20 were ordered later. Units were numbered 321301-366. These units replaced slam-door Class 305, Class 307, Class 308 and Class 309 units on trains to Clacton and Southend-on-Sea, and worked services on the newly electrified routes to Ipswich and Harwich. They also displaced many Class 312 slam-door units, which moved over to the London, Tilbury and Southend line. Some of the Class 309s were retained until 1994, and 24 of the newer Class 312 units were retained long-term to work services to Walton-on-the-Naze and peak services to Clacton, Ipswich and Witham. Units carried Network SouthEast livery from new. In March 2008, 321361 was named Phoenix at Ilford depot after it was rebuilt at the disused Colchester shed to repair damage caused by an arson attack at Southend Victoria on 10 July 2007. The first of 30 321/3 units to be refurbished at Doncaster Works, as part of the Renatus project which modernised the stock with features such as new air conditioning and