Wikipedia
Electrostar is the name given to a series of related electric multiple-unit (EMU) passenger trains manufactured by Bombardier Transportation (formerly ADtranz) at their Litchurch Lane Works in Derby, England. Since the privatisation of British Rail, it has become the most common new EMU type in Britain, where different variants referred to as Class 357, Class 375, Class 376, Class 377, Class 378, Class 379 and Class 387, are most common on the high-volume suburban commuter routes in South, North and East London, and mainline services south to Surrey, Sussex, Kent & South Essex coasts and north to Cambridge and Stansted Airport . It shares the same bodyshell and core structure as the Turbostar, which is in turn the most common post-privatisation diesel multiple unit (DMU) family, and both evolved from the Class 168 Clubman design by ADtranz.
The Clubman/Turbostar/Electrostar platform is a modular design, which share the same basic design, bodyshell and core structure, and is optimised for speedy manufacture and easy maintenance. It consists of an underframe, which is created by seam-welding a number of aluminium alloy extrusions, upon which bodyside panels are mounted followed by a single piece roof, again made from extruded sections. The car ends (cabs) are made from glass-reinforced plastic and steel, and are huck-bolted onto the main car bodies. Underframe components are collected in ‘rafts’, which are bolted into slots on the underframe extrusion. The mostly aluminium alloy body gives light weight to help acceleration and energy efficiency.
The Electrostar was also selected for use on the Gautrain system in South Africa, a new railway between Johannesburg, Pretoria, and the Johannesburg International Airport. The trains were assembled by UCW Partnership in South Africa from components made in Derby.
Transport for London (TfL) announced in August 2006 that it had ordered 48 three- and four-car Electrostar trains for the new London Overground service. These were categorised by Network Rail as Class 378, and entered service in 2009 to replace the Class 313 and Class 508 on the North London Line and West London Line, and to provide the opening service on the new East London line extension from 2010.
In 2009, as part of the government's wider rolling stock plan, an order was placed for thirty four-car Class 379 Electrostar units intended for use by National Express East Anglia (now operated by Abellio Greater Anglia) on the Stansted Express and West Anglia services. The first of the new Class 379 units entered passenger service on Thursday 3 March 2011 running the 20:10 Stansted Express from London Liverpool Street to Stansted Airport and the 21:15 return service.