British Rail Class 323

The British Rail Class 323 is a class of electric multiple unit (EMU) passenger train built by Hunslet Transportation Projects and Holec. All 43 units were built from 1992 through to 1995, although mock-ups and prototypes were built and tested in 1990 and 1991.

Entering service in 1994, the 323s were among the last trains to enter service with British Rail before its privatisation in the mid-1990s. The units were designed to operate on inner-suburban commuter lines in and around Birmingham and Manchester with swift acceleration and high reliability. Of the 43 units built, 25 are in operation with West Midlands Railway and 18 with Northern Trains. In the first half of 2024 the West Midlands Railway units are planned to be replaced by new EMUs, and 34 units will be operated by Northern Trains.

The units are known for their rapid acceleration, being the fastest accelerating trains on the UK rail network, and also for the distinctive whining sounds that can be heard during acceleration or deceleration. These sounds are generated by the traction electronics. They were also among the first trains to be built from aluminium rather than steel in the UK.

Background
In 1990, the Regional Railways sector of British Rail tendered an order for new EMUs, both to replace older electric units around Birmingham and Manchester, and to work services on the newly electrified Birmingham Cross-City Line. In June 1990, the contract was awarded to Hunslet Transportation Projects of Birmingham, a new company set up by a team of engineers and managers who had left Metro-Cammell (at that time a Birmingham-based train builder). It won the contract in competition with six other European train builders. The trains were designed in Birmingham, but built and fitted out at the Hunslet works in Leeds, with the traction motors supplied by the Dutch firm Holec.

Initially 37 units were ordered, with the option for fourteen more. Eighteen would be needed for the Cross-City Line, while the remainder would replace older units (such as the and ); ultimately a total of 43 three-car units were actually built. When the electrification of the Leeds/Bradford – Skipton/Ilkley Airedale/Wharfedale Lines was confirmed in the early 1990s, Regional Railways and West Yorkshire PTE applied to the government for fourteen units to add to those already on order. At the time, government spending on the railways was restricted due to the impending privatisation of British Rail and eventually, when funding was not forthcoming, the order was cancelled. Instead 21 second-hand Class 308 units from Network SouthEast were used until new EMUs entered service in 2001.

The units are known for a distinctive whine made during acceleration or deceleration, rising/falling through multiple phases falsely suggestive of a motor connected to a gearbox with a great many ratios, caused by use of a gate turn-off thyristor-based inverter as part of the traction control circuitry that drives the three-phase AC motors, a common setup in the early-to-mid 1990s which is notably also present in the Networker family of EMUs. The "gear-changing" effect is produced by the simplification of the PWM pulse pattern so as not to overload the thyristor, which switches at lower frequencies than later implementations of the variable-frequency drive and hence produces a lower-pitched sound.

British Rail service
The Class 323s were initially beset with a number of technical problems related to their traction motors, doors, traction converters, gearbox and vibration at high speed which took several years to resolve, preventing them from entering service. The first unit finally entered revenue-earning service on 7 February 1994. A mixed fleet of elderly diesels which the 323s had been intended to replace, as well as some elderly, and  electric units, were drafted in to operate Cross-City Line services until the problems were resolved. Electric services began on 26 November 1992 on the northern section of the Cross-City Line, before the entire route was energised in June the following year. The 323s became reliable enough to operate a full service in 1995.

Post-privatisation service
As part of the privatisation of British Rail, all 43 were sold to Porterbrook in 1994 and allocated to the Central Trains and North West Regional Railways shadow franchises.

West Midlands
Central Trains inherited from British Rail a fleet of 26 units in two blocks; 323201–323222 and 323240–323243. In November 2007, these passed to London Midland when it took over the franchise.

In December 2017, West Midlands Trains took over the West Midlands franchise, and the 323s passed to that company. It is expected that they will be replaced by new units on the Cross-City Line in the first half of 2024.

In mid-to-late 2019, a number of West Midlands Trains' Class 323 units were used for an in-service pilot test of retrofitted Double Variable-Rate Sanders, sponsored by the Rail Safety and Standards Board. The test demonstrated that the new sanding equipment significantly improved braking performance in low-adhesion conditions.

To celebrate 30 years service in the West Midlands unit 323221 was repainted into the Centro livery.

To celebrate 30 years of operation of Soho Depot where the West Midlands fleet is maintained, the West Midlands fleet had Soho LMD 1993 Cross City Line Diamond logos applied to them.

North West
The units were used to replace older stock of Classes and, although some of the latter were retained in reserve until 2000. They are used on the Manchester electrified network, primarily to the south of the city.

At the time of the privatisation of British Rail, the Regional Railways North West franchise was re-branded North Western Trains, and it inherited 17 of these units (323223–323239). North Western Trains became First North Western in 1998 and its operations were taken over by Northern Rail in 2004. All passed to Arriva Rail North with the franchise in April 2016, and then to current operator Northern Trains on 1 March 2020.

The fleet is currently maintained at Allerton TMD, with units terminating in Manchester stabled at Stockport Edgeley carriage sidings where they receive overnight cleaning as well as Ardwick TMD operated by Siemens, where they are washed alongside the TransPennine Express fleet. The 323s were formerly maintained at Longsight Electric TMD.

In the future the fleet will be stabled and maintained at Manchester International Depot.

Refurbishment
As part of a refurbishment in the early 2000s, the Class 323 fleet received guard's door control panels in the trailer vehicles.

Class 323s operated by both Northern Trains and West Midlands Railway received a full refurbishment between 2018 and 2021, with the first refurbished units delivered to West Midlands Railway in February 2019, and the first Arriva Rail North unit (323234) returning on 22 October 2019. The rest of fleet was refurbished to the same standard over the following years.

These works involved the replacement of seat covers, interior and exterior repainting (into the new livery of their respective operators), the installation of a new passenger information system and wheelchair call-for-aid buttons, and the addition of an accessible toilet in place of the original small toilet cubicles, among other modifications. The last Class 323 unit to be refurbished (323224) returned to Northern Trains on 23 January 2021, while the last West Midlands Railway 323 unit was returned in 2020.

Many of these changes were a requirement of the PRM (Persons with Restricted Mobility) TSI, with which all UK trains have to be compliant.

Accidents and incidents
On 18 December 2008, unit 323231 collided with a Nissan 4x4 which had rolled down the embankment from a delivery company car park at North Rode, Congleton. The unit spent 16 months out of service to undergo repair as a result.

On 17 December 2019, unit 323234 derailed in the Ardwick train depot. The train rolled approximately 4 feet away from the railhead and where it had ended up. No one was hurt in the accident as it occurred at a low speed.

Future
The 323s were expected to leave Arriva Rail North in December 2018 when replaced by the fleet,    but this did not occur. Instead, the Class 323 fleet was retained – and will be enlarged with a cascade of 17 units from West Midlands Railway.

The 17 West Midlands Railway units to be transferred to Northern once the Class 730s enter service, started to receive "digital modifications" in 2023. The first of these trains (323208) was transferred to Northern in October 2023.

Named units
The following units have received names:
 * 323201: Duddeston (de-named)
 * 323202: Butlers Lane (de-named)
 * 323203: Aston (de-named)
 * 323204: Selly Oak
 * 323205: Blake Street (de-named)
 * 323206: Barnt Green (de-named)
 * 323207: Bournville (de-named)
 * 323208: Five Ways (de-named)
 * 323209: Birmingham New Street (de-named)
 * 323210: Shenstone (de-named)
 * 323211: Four Oaks (de-named)
 * 323212: Bromsgrove (de-named)
 * 323213: Sutton Coldfield (de-named)
 * 323214: Wylde Green (de-named)
 * 323215: Gravelly Hill
 * 323216: University
 * 323217: Chester Road (de-named)
 * 323218 Lichfield City (de-named)
 * 323219: Kings Norton
 * 323220: Lichfield Trent Valley (de-named)
 * 323221: Northfield (subsequently de-named)
 * 323222: Redditch (de-named)
 * 323240: Erdington (de-named)
 * 323241: Dave Pomroy 323 Fleet Engineer 40 Years Service. (de-named)
 * 323242: Alvechurch
 * 323243: Longbridge (de-named)

Awards
At the 2023 Gold Spanner awards, the West Midlands Trains Class 323 fleet won a Silver spanner award for the "most improved Ex-BR EMU fleet over the past year".