The Bombardier Turbostar (sold as the ADtranz Turbostar until 2001) is a family of diesel multiple unit (DMU) passenger trains that was built by ADtranz and later Bombardier Transportation at Derby Litchurch Lane Works in the United Kingdom between 1997 and 2011. The Turbostar was the first new train type to be introduced after the privatisation of British Rail. The first units were ordered by Chiltern Railways in 1996 and were designated Class 168 (also known as Clubman). Since then the family has grown with the addition of the Class 170, Class 171, and the Class 172. Description and technical details The Turbostar and Electrostar platforms are a modular design, which share the same basic design, bodyshell and core structure, and are optimised for speedy manufacture and easy maintenance. They consist of a common 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. Much of the design of the Class 168/170/171 is derived from the Networker Turbo Class 165 and Class 166 trains built by British Rail Engineering Limited's Holgate Road carriage works. Notable features shared are the aluminium alloy frame and two-stage Voith T211r hydrodynamic transmission system. The diesel engine has changed to an MTU 6R 183TD13H. A cardan shaft links the output of the gearbox to ZF final drives (instead of Gmeinder in the Networkers) on the inner bogie of each vehicle. The engine and transmission are situated under the body; one bogie per car is powered, the other bogie unpowered. The Class 172 differs mechanically to its older relations in several ways. The engine used is the more powerful and cleaner MTU 6H1800R83, the transmission is the mechanical 6-speed ZF Ecomat-Rail, and lighter Bombardier FLEXX-ECO bogies and hollow axles are used as well as half-height airdams. The exhaust system is also quieter and does not have the distinctive note of that of the Class 168/170/171. Turbostars have been acquired for use by several train operating companies, each with different specifications. One of the more noticeable differences with later units