British Rail Class 171

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


The Southern fleet are fitted with coupling devices (Dellner) different from other Turbostars, and are classified as Class 171 for this reason. 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.

These trains have electronic automated station announcements and onboard displays unlike their predecessors.

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.

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.