British Rail Class 171


The British Rail Class 171 Turbostar is a type of diesel multiple-unit train built by Bombardier Transportation at its Derby Litchurch Lane Works in England, which is identical to the Class 170, except for the replacement of the BSI coupler with a Dellner coupling. This provision was made to allow emergency joining with Class 377 DC third-rail electric units, which Southern runs extensively on most lines. The vehicles work on the southern regions of the British railway system, operating services from London Bridge to Uckfield and from Eastbourne to Ashford International, these routes being unelectrified between Hurst Green Junction and Uckfield and between Ore and Ashford International, respectively.
The fleet is operated by Govia Thameslink Railway for Southern services.

Design

The Southern fleet is fitted with coupling devices different from other Turbostars, and is 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 the 170 392 unit 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. This unit was first delivered carrying Southern livery and the number 170 727. It never operated in this form and was transferred to South West Trains where it became 170 392.
These trains have electronic onboard displays and automated next station announcements.

Seating

Class 171s have mainly standard-class seating plus either nine first-class seats on a two-car or 18 on a four-car; all first-class seats are reclining and have AC power sockets adjacent to the seats.
Standard-class seating includes five full-size folding seats in the area by the universal toilet on the DMOCL vehicle. With these seats folded there is room for wheelchair users and bicycles. Each passenger door vestibule area also has two flip-down seats.

Operations

acquired an initial fleet of six two-car Class 171/7 and six four-car Class 171/8 units, to replace the slam-door Class 205 and Class 207 "Thumper" fleet.
The first units were introduced in 2003 on the Marshlink Line from Ashford to and were extended in 2005 to, but in 2018 the service was cut back to due to overcrowding and a shortage of additional diesel stock. Services on the to branch of the Oxted Line were later also transferred to Turbostar operation. Services from London Bridge to Uckfield went over to Turbostar operation in late 2004.
The Ashford-Eastbourne service, as well as peak-time Ashford-Rye and Ashford-Hastings shuttle services, are nearly always operated by the two-car Class 171/7; the four-car Class 171/8 units occasionally appear on the route during special events such as the Rye bonfire celebrations.
The Uckfield-London Bridge and Uckfield-Oxted services use both the two-car and the four-car units. These units are often coupled together, forming 6-car, 8-car or 10-car trains following platform extensions at Uckfield line stations.

Future

Twelve units are scheduled to move to East Midlands Railway and be converted back to Class 170s with their carriage configuration also being changed to create 2 and 3 car units in 2021.

Fleet details

Initial deliveries took place when the original 2-car units, at the time classified as Class 170/7, entered service in 2003, followed by the 4-car Class 171/8 units in 2004. At this time, the 2-car sets received their Dellner couplings and were reclassified as Class 171/7. In 2015, four 3-car Class 170/4 units were transferred to Southern from First ScotRail to enhance the fleet; two of these had the centre car removed and added to the remaining two, to form a pair of 2-car and a pair of 4-car units. With the addition of Dellner couplings, the new units were reclassified as Class 171/2 and 171/4.
Formation of 2-Car Class 171/7: DMOCL + DMOSL
Formation of 4-Car Class 171/8: DMOCL + MOS + MOS + DMOCL
ClassOperatorNumber builtYear builtCars per setUnit nos.Notes
Class 171/2Southern21999-20012171201 - 171202Converted from former First ScotRail Class 170 units in 2016.
All units to transfer to East Midlands Railway and be converted back to s
Class 171/4Southern21999-20014171401 - 171402Converted from former First ScotRail Class 170 units in 2016.
All units to transfer to East Midlands Railway and be converted back to s
Class 171/7Southern102003–20042171721 - 1717306 units to transfer to East Midlands Railway and be converted to s, 171730 formerly 170392
Class 171/8Southern620044171801 - 1718062 units to transfer to East Midlands Railway and be converted to s