Bombardier Turbostar
| Company type | Product line |
|---|---|
| Industry | Rail transport |
| Predecessor | ADtranz Turbostar |
| Founded | 1997 |
| Headquarters | Derby , United Kingdom |
| Products | Diesel multiple unit passenger trains (Classes 168, 170, 171, 172) |
| Parent | Bombardier Transportation |
The Bombardier Turbostar—initially promoted as the ADtranz Turbostar until 2001—is a series of diesel multiple unit (DMU) passenger trains manufactured by ADtranz and subsequently Bombardier Transportation at the Derby Litchurch Lane Works facility in the United Kingdom between 1997 and 2011. This family was the first new train model introduced following the privatisation of British Rail. The inaugural orders originated from Chiltern Railways in 1996, resulting in the Class 168 (nicknamed Clubman). The lineup later grew to encompass the Class 170, Class 171, and Class 172 variants.
Description and technical details
Both the Turbostar and Electrostar platforms utilize a modular architecture, sharing an identical bodyshell and fundamental framework designed to facilitate swift production and straightforward upkeep. Their common underframe is fabricated by seam-welding aluminium alloy extrusions, complemented by bodyside panels and a single-piece extruded roof. The ends of each car (cabs) are assembled from glass-reinforced plastic combined with steel, secured to the body using Huck-bolts. Underframe elements are organized into ‘rafts’ that are bolted into designated slots within the extrusion. The extensive use of aluminium alloy in the bodywork reduces overall weight, thereby improving acceleration and energy consumption.
The design of Classes 168, 170, and 171 traces its roots to the Networker Turbo models—specifically the Class 165 and Class 166—built by British Rail Engineering Limited’s Holgate Road works. Commonalities include an aluminium alloy frame and a two-stage Voith T211r hydrodynamic transmission system. The diesel powerplant was upgraded to an MTU 6R 183TD13H engine, with a cardan shaft transmitting power from the gearbox output to ZF final drives located on each vehicle’s inner bogie. Each carriage has one powered bogie while the other remains unpowered.
The Class 172 introduces mechanical distinctions such as a more potent and environmentally cleaner MTU 6H1800R83 engine paired with a mechanical six-speed ZF Ecomat-Rail transmission. It also features lighter Bombardier FLEXX-ECO bogies, hollow axles, and half-height airdams. Additionally, its exhaust system operates more quietly, lacking the characteristic sound found in earlier versions.
Different train operating companies have procured Turbostar units configured with varying specifications; more recent models include larger headlights to improve safety standards.
Fleet numbers follow the pattern 168 xxx, 170 xxx, 171 xxx, or 172 xxx for units, while individual cars carry numbers such as 50xxx and 79xxx for driving motor cars, alongside 54xxx, 55xxx, and 56xxx for intermediate vehicles.
Working in multiple
One of the primary reasons behind the Turbostars’ widespread adoption is that Class 170 trains can be coupled for multiple working not only with other Class 170 units but also with older Class 15x Sprinter trains—an operational flexibility uncommon among most post-privatisation rolling stock. Nevertheless, formations known as "sandwich" sets (e.g., 170-15x-170 or 15x-170-15x) pose difficulties during empty stock transfers where up to four mixed units may be linked together. As a result, Turbostars exhibit performance comparable to second-generation Class 15x trains; they can be slower than a Class 150 or Class 156 on short journeys and may lag behind a Class 158 over longer distances unless able to operate at their maximum speed of 100 mph.
Unlike Class 170s that utilize BSI couplers, Class 171 trains are equipped with Dellner couplers, enabling them to mechanically couple with Southern’s fleet of Class 377 Electrostar EMUs for rescue purposes.
Variants
| Class | Image | Operator | Year Introduced | Quantity | Number of Carriages | End Gangways |
|---|---|---|---|---|---|---|
| 168 Clubman | 1998 | 28 | 2, 3, or 4 | Absent | ||
| 170 Turbostar | 122 | 2 or 3 | ||||
| 171 Turbostar | 2003 | 17 | ||||
| 172 Turbostar | 2010 | 39 | Only in 172/2 and 172/3 | |||