British Rail Class 171

British Rail Class 171 Turbostar
Southern Class 171/8, no. 171 802 on display at the York Railfest exhibition on 3 June 2004
Interior of a Class 171 featuring a customer information system display
In service	2003 - Present
Manufacturer	Bombardier Transportation
Family name	Turbostar
Constructed	2003 - 2004
Number built	16 trainsets
Formation	2/4 cars per trainset
Fleet numbers	171 721 - 171 730 171 801 - 171 806
Capacity	107 seats (2 Car) 241 seats (4 Car)[1]
Operator	Southern
Specifications
Car length	23.62 m (77 ft 6 in)
Width	2.69 m (8 ft 10 in)
Height	3.77 m (12 ft 4 in)
Maximum speed	100 mph (160 km/h)
Weight	Class 171/7: 90.41 tonnes (88.98 long tons; 99.66 short tons) Class 171/8: 176.21 tonnes (173.43 long tons; 194.24 short tons)
Engine(s)	One per car, 422 hp (315 kW) MTU 6R 183TD Diesel
Transmission	Voith Hydraulic T211rzze 2 axles driven per car
Braking system(s)	Air[1]
Safety system(s)	AWS, TPWS
Coupling system	Dellner
Gauge	1,435 mm (4 ft 8 1⁄2 in) Standard gauge

The Class 171 Turbostar is a type of diesel multiple unit (DMU) built by Bombardier Transportation (previously ADtranz) at their Litchurch Lane Works in Derby, England which is identical to the Class 170, except for the replacement of the BSI (Bergische Stahl Industrie) coupler with a Dellner coupler. This provision was made to allow emergency joining with Class 377 DC third-rail electric units. The vehicles work on the southern regions of the British railway system.

Design

Class 170 on the left has a BSI 'Compact' coupler whereas Class 171 on the right has a Dellner coupler.

The Southern fleet are fitted with coupling devices (Dellner) different from other Turbostars, and are classified as Class 171 for this reason.^[2] The four-car units were built with the new couplers, but Class 170 two car units were fitted at a later date, and reclassified as Class 171/7 after the modification. Three more two-car units were later acquired, but these were built from new with the new couplers.

Southern gained 170 392 from South West Trains. The coupler on this unit has also been changed to the Dellner type. The unit has been reclassified and renumbered from 170 392 to 171 730. Ironically this unit was first delivered carrying Southern livery and the number 170 727 (this was due to the fact SWT needed another 170 and it was cheaper to place another unit on the Southern order than place a new order). It never operated in this form and transferred to South West Trains where it became 170 392.

171 730 is unique regarding its seating as it has four more seats than all other 171/7 units, totalling 111 seats.^[1]

These trains have electronic automated station announcements and onboard displays unlike their predecessors.^{[3][clarification needed]}

Operations

Southern (previously named South Central) acquired an initial fleet of six 2-car Class 171/7 and six 4-car Class 171/8 units, to replace its ageing Class 205 and Class 207 "Thumper" fleet.^[4]

The first units were introduced in 2003 on Ashford to Hastings "Marshlink Line" (now running further to Brighton). Later services on the Oxted to Uckfield branch of the Oxted Line were also transferred to Turbostar operation. The services from London Bridge to Uckfield went over to Turbostar operation in late 2004.

2 Car Class 171/7 run the Brighton to Ashford International service via Lewes, Eastbourne and Hastings, whereas 4 Car 171/8 run the London Bridge to Uckfield via Oxted service. The 4 car units occasionally appear on the Marshlink Line during special events such as the Rye Bonfire celebrations.

Fleet details

Class	Operator	Number built	Year built	Cars per set	Unit nos.
Class 171/7	Southern	10	2003–2004	2	171 721 - 171 730 [5]
Class 171/8		6	2004	4	171 801 - 171 806 [5]

References

1. ^ ^{a b c} Marsden, Colin J. (2007). Traction Recognition. Ian Allan Publishing. ISBN 978-0-7110-3277-4. 
2. ^ Class 171 - Welcome to the Southern E-Group Web Site. Retrieved 2011-05-01.
3. ^ Southern On Train Facilities - Retrieved 2011-05-10.
4. ^ Class 170 2Page - Welcome to the Southern E-Group Web Site. Retrieved 2011-05-01.
5. ^ ^{a b} http://www.thejunction.org.uk/flist_171.html The Junction Class 171 Fleet List