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British Rail Class 450

British Rail Class 450 Desiro
A South Western Railway Class 450 at Barnes in 2023
Refurbished standard-class saloon
In service5 October 2003 – present
ManufacturerSiemens Transportation Systems
Built at
Family nameDesiro
Replaced
Constructed2002–2006
Refurbished2017–2020
Number built127
Formation4 cars per unit:
DMOC-TOSL-TOSLW-DMOC
Fleet numbers450001–450127
Capacity
  • As built: 264 seats
    (24 first-class, 240 standard)
  • As refurbished: 285 seats
    (16 first-class, 269 standard)
OwnersAngel Trains
OperatorsSouth Western Railway
DepotsNortham
Specifications
Car body constructionAluminium
Train length81.60Β m (267Β ft 9Β in)
Car length20.34Β m (66Β ft 9Β in)
Width2.796Β m (9Β ft 2.1Β in)
Floor height1.157Β m (3Β ft 9.6Β in)
Wheel diameter850–786Β mm (33.46–30.94Β in) (new–worn)
WheelbaseBogies: 2.600Β m (8Β ft 6.4Β in)
Maximum speed100Β mph (160Β km/h)
Weight
  • 175.71 tonnes (172.93 long tons; 193.69 short tons)
Traction systemSiemens SIBAS IGBT
Traction motors8 Γ— Siemens 1TB2016-0GB02
asynchronous three-phase AC
Power output1,500Β kW (2,000Β hp) (at wheel)
Tractive effortStarting: 200Β kN (45,000Β lbf)
Accelerationapprox. 1Β m/s (3.3Β ft/s)
Electric system(s)750Β VΒ DCΒ third rail
Current collector(s)Contact shoe
UIC classificationBoβ€²Boβ€²+2β€²2β€²+2β€²2β€²+Boβ€²Boβ€²
BogiesSiemens SGP SF5000
Minimum turning radius120Β m (393Β ft 8Β in)
Braking system(s)Electro-pneumatic (disc) and regenerative
Safety system(s)
Coupling systemDellner 12
Multiple workingWithin class, and with Class 444
Track gauge1,435Β mm (4Β ftΒ 8+1⁄2Β in) standard gauge


The British Rail Class 450 Desiro is a type of third-rail DC electric multiple unit (EMU) passenger train that entered service during 2003. Used for outer-suburban services, the units were built with both first- and standard-class accommodation. They have a maximum speed of 100Β mph (160Β km/h).

The Desiro UK family also includes units of Classes 185, 350, 360, 380 and 444.

Along with the Class 444 Desiro, the Class 450 units are operated by South Western Railway.

Introduction


A Class 450 unit between two Class 421s at Clapham Junction depot in February 2005, less than three months before the latter were withdrawn.

In April 2001, 785 vehicles were ordered by South West Trains in order to complete the replacement of its slam-door rolling stock, in accordance with its franchise commitment to do so by 2005, as the slam-door trains, many of which were more than 40 years old, did not meet modern health and safety requirements. Introduction to service was delayed by the required power supply upgrades capable of powering the new trains, which feature air conditioning, a feature not present in the slam-door trains they replaced. In the December 2004 timetable change, the Class 450 Desiro began serving most intended routes, although introduction was delayed until June 2005 in some areas. The units are leased by Angel Trains to South Western Railway.

Sixty-eight new vehicles were ordered by South West Trains as a replacement to the growth order which was diverted to form the similar Class 350 range of electric multiple units.

Operations


South West Trains Class 450 unit at Camberley in 2011
South West Trains Class 450 unit near Clapham Junction in 2012

Class 450 units operate suburban, outer-suburban, and regional services from London Waterloo. They are used on all SWR lines except the non-electrified West of England Main Line and Eastleigh to Romsey Line.

On occasion Class 450 units are also used on the Portsmouth Direct Line for services between Waterloo and Portsmouth Harbour, in place of the intended Class 444. The difference in comfort – particularly the higher-density 2+3 seating arrangement used on the Class 450 fleet – has prompted complaints from some passengers affected by the substitution.

Both the Class 444 and 450 fleets are maintained at the purpose-built Northam Traincare Facility in Southampton, which is equipped to perform both preventative and corrective maintenance, deep-cleaning, and overhauls on up to eight units simultaneously.

In March 2012, the Class 450 fleet, along with the Class 458 and 444 fleets, was fitted with regenerative braking.

Class 450/2 and more orders

Originally, SWT's order with Siemens was for 100 four-car sets (the current 450/0) and 32 five-car sets, intended as Class 450/2 for inner-suburban use. The Strategic Rail Authority, however, did not agree to the terms required, such as the lengthening of platforms and changes to railway infrastructure. As a result, the 32 five-car sets were cancelled and the 160 vehicles redistributed; an extra 10 four-car sets were added to the SWT order, while the remaining 120 vehicles were then ordered as 30 four-car sets of the dual-voltage Class 350 for Silverlink and Central Trains.

Subsequently, SWT received further 17 four-car sets, bringing the total number of Class 450 units up to 127. These trains were delivered in 2006, not long after the last of the first order was delivered.

Class 450/5 modifications

In January 2008, 28 Class 450/0 sets were modified and re-numbered in the Class 450/5 series, for use on services between Waterloo and Windsor, the Hounslow Loop Line, as well as between Waterloo and Weybridge. They had their first-class seating removed and replaced with 2+3 formation standard-class seating, and some other seats were removed to provide more standing capacity; extra handrails were also provided. The numbers modified are 450043 to 450070, which have become 450543 to 450570 respectively and displayed the letters HC (denoting 'High Capacity') above the unit number on the front of the sets. The modifications were carried out at the Bournemouth Traincare Depot.

In anticipation of the Class 458/5 modifications for use on the Windsor Lines, the 450/5 sub class had the First Class reinstated, and they are now used generally across the SWR routes. These trains retained their 4505xx number as the standard seating configuration remained different but as they completed their SWR interior refurbishment during late 2019 they were returned to their original numbers.

Refresh


South Western Railway, as part of its franchise award in 2017, has carried out a refurbishment programme on its Class 450 fleet. As part of this, every unit has been deep cleaned with carpets and seat covers replaced and every two seats in standard class have had a plug socket fitted. The 24 first class seats carried in the centre of one of the intermediate trailers were replaced with standard-class rows, while new first-class areas of eight seats each were installed immediately adjacent to each driver's cab. These areas feature new leather seats and tables with wireless charging facilities. As part of this work, subclass /5 high-capacity units have also been similarly refurbished, and returned to their original numbers, meaning that all Class 450s once again share a common layout.

Accidents and incidents


On 6 November 2017, unit 450025 was derailed near Wimbledon. Four people were injured; over 300 passengers were evacuated from the train. The accident was caused by track spread (an increase in the distance between rails), and occurred on a 120-metre (131Β yd) stretch of line that had not been inspected or maintained for many years because of a misunderstanding between Network Rail and London Underground as to which company was responsible for its upkeep.

On 4 March 2024, unit 450092 was derailed between Woking and Surbiton stations when it struck an obstruction on the line whilst travelling at a speed of 90Β mph (140Β km/h). No-one was injured and the train was safely evacuated.

Fleet details


Class Operator Qty. Year built Cars per unit Unit nos.
450 South Western Railway 127 2002–2006 4 450001–450127

Interiors

Illustration

Illustration of a South Western Railway Class 450 unit

Named units

Some units have been named:

  • 450015 - Desiro
  • 450042 - Treloar College
  • 450067 - Key Workers - also given a special livery
  • 450100 - Transport Benevolent Fund CIO
  • 450114 - Fairbridge Investing in the Future (de-named)
  • 450127 - Dave Gunson


Last updated 24 June 2025. All information and images sourced from the relevant Wikipedia article(s) unless stated otherwise. If any information is incorrect, please let us know by emailing us: [email protected]. Text is available under the Creative Commons Attribution-ShareAlike License 4.0; additional terms apply.