Class 455 (BREL York Suburban Services 4-car)

The Class 455 electric multiple unit uses the former Southern Railways/Region 750v DC third rail system. The units were built in the early 1980s to replace 4-SUB and EPB stock by BREL York [1] and are examples of 1982 Standard High Density Stock. All in all 137 sets were built between 1983 and 1985. Currently they are operated by Southern and South West Trains on commuter lines out of Waterloo, Victoria and London Bridge.

Number built: 548* (137 4-car sets)
* including 43 cars from Class 508s
Built: 1983-85
Builder: BREL York
Engine: 4 EE507-20J traction motors per set (750v DC third rail)
Power: 1, 000 hp (746 kW)
Formation: Driving Trailer Standard Open (DTSO)+Motor Standard Open (MSO)+
Trailer Standard Open (TSO)+DTSO

The units were based on the work behind the prototype Class 210 DEMUs and are related to the Class 317 and 318, like them being derived from the British Rail Mark 3 coach [2]. There are 3 sub-classes: 455/7, 455/8 and 455/9 all of which remain in use, a major visual difference is that the /7 and /9 sub-classes have a more rounded roof than the /8 which despite the numbering was built first. 455/7s were built as 3-car sets but included a carriage (TSO) taken from the Class 508 EMUs which they replaced to make them 4-car. Since privatisation the Southern 455/8s have lost their cab gangways in favour of an air conditioning unit and now look different from the other sub-classes.

They were set to remain in service into the 2020s following refurbishment and the fitting of new traction motors to some units [3]. (It is worth noting that the replaced motors are reconditioned English Electric motors from older SR EMUs such as the Class 405 and indeed dated from the early post-war period!)

However the change in the South West Trains franchise in 2017 will probably see SWT's 455s withdrawn by 2020 [4] though as yet there are no plans to replace Southern's 455s. This might not be the end of the story however as there are plans to explore fitting surplus 455s with diesel engines to turn them into bi-mode multiple units following on from the Class 319 Flex / Class 769 [5].
SWR 455 746 at Clapham Junction

SWT 5917 at Guildford

Southern 455 810 at Peckham Rye

Aboard an SWT 455

Southern 455 838 and 815 at London Bridge

SWT 5712 at Vauxhall

[1] Colin J. Marsden, DMU and EMU Recognition Guide (Ian Allan, 2013) p. 351
[2] Brian Haresnape & Alec Swain, Third Rail DC Electric Multiple Units (Ian Allan, 1989) p. 77
[3] "Vossloh Kiepe UK to deliver traction upgrade to South West Trains’ Class 455 fleet">
[4] "Class 455 Death Sentence", Modern Railways (May 2017) p. 25
[5] "'319 Flex' units to be Class 769", Modern Railways (June 2017) p. 85