British Rail Class 321

In September 1987, Network SouthEast ordered 46 321/3s for use on services from London Liverpool Street to Cambridge and Southend Victoria. The first was unveiled on 15 September 1988.[4] A further 20 were ordered later.[1][5] Units were numbered 321301-366.

These units replaced slam-door Class 305, Class 307, Class 308 and Class 309 units on trains to Clacton and Southend-on-Sea, and worked services on the newly electrified routes to Ipswich and Harwich. They also displaced many Class 312 slam-door units, which moved over to the London, Tilbury and Southend Railway. Some of the Class 309s were retained until 1994, and 24 of the newer Class 312 units were retained long-term to work services to Walton-on-the-Naze and peak services to Clacton, Ipswich and Witham. Units carried Network SouthEast livery from new.

In March 2008, 321361 was named Phoenix at Ilford depot after it was rebuilt at the disused Colchester shed to repair damage caused by an arson attack at Southend Victoria on 10 July 2007.[6]

The first of 30 321/3s to be refurbished at Doncaster Works, as part of the Renatus project – which modernised the stock with features such as new air conditioning and heating, seating and Wi-Fi – was completed in December 2016.[7][8][9]

321401 in Network SouthEast livery at Rugby

In October 1988 a second batch of 30 was ordered. It was intended that 25 be used on Great Eastern Main Line services and five on West Coast Main Line services, but in the event all were delivered to Bletchley TMD for use on the latter. A further 18 followed.[5] Units were numbered 321401–321448. The first was delivered in July 1989.[10]

These were built for outer-suburban services on the West Coast Main Line, from London Euston to Northampton, Rugby and Birmingham New Street. They displaced the then-recently cascaded Class 317s dating from 1981 which had themselves only just been introduced to the route to replace Class 310 units.[5]

Eleven 321/4s were transferred for Great Eastern Main Line services. Following this their First Class area was reduced in size to standardise with the 321/3 units in useon that route. This involved removal of the centre partition and double doors and re-upholstering the First Class style 2+2 seats (which were retained at that time) in the de-classified area into the same fabric as the Standard Class seats. Later the First Class 2+2 seats in this de-classified area were replaced with the standard style 2+3 seating. These 11 units were also fitted with a facility to lock out the power door operation within the unit (a basic kind of Selective Operation) to permit operation of 12-car trains on the Braintree and Southminster branch lines, where some platforms were only long enough for 8-car trains.

The 11 Great Eastern sets passed to First Great Eastern in January 1997, passing with the franchise to National Express East Anglia in April 2004 and Abellio Greater Anglia in February 2012. The 37 West Coast sets passed to Silverlink in January 1997, passing with the franchise to London Midland in November 2007. In 2006 unit 321423 was loaned to Northern Rail while the 321/9s were being overhauled.

Following the delivery of the Class 350/2 fleet, 13 Class 321/4s (401–410, 418–420) were transferred from London Midland to First Capital Connect and overhauled by Wabtec's Doncaster Works.[11][12] These passed with the franchise to Great Northern in September 2014. London Midland also released 17 (421–437) for transfer to National Express East Anglia. The remaining seven (411–417) passed to Abellio ScotRail in 2015, after being converted to three-car Class 320/4 at Doncaster Works.[13]

In 2017 ten units (402, 405–410, 418–420) were transferred from Great Northern to Abellio Greater Anglia.[14] As at May 2018 the remaining three (401, 403, 404) are to be converted by Wabtec at Kilmarnock to Class 320/4 for use with Abellio ScotRail. Another two were to follow.[15][16]

321903 in West Yorkshire Passenger Transport Executive livery at Doncaster

The final batch of three Class 321 were classified 321/9 and were constructed in 1991,[1] as an add-on to the main batches. These units have a similar formation to the earlier units except that there is no first class seating. They were ordered by Regional Railways for use on West Yorkshire Passenger Transport Executive services on the newly electrified Doncaster to Leeds route, entering service in 1993. From 1995 they also worked on Wharfedale line services from Leeds to Ilkley.[17] In March 1997 they passed with the Regional Railways North East franchise to Northern Spirit, which became Arriva Trains Northern in April 2001. In June 1998 they were loaned to GNER to operate Leeds to London King's Cross services while its InterCity 225 fleet was grounded with mechanical issues.[18] All three passed with the franchise to Northern Rail in December 2004.

The Class 321/9 units were refurbished at Hunslet-Barclay, Kilmarnock from late 2006 to early 2007.[19] The refurbishment included a new livery, refurbished interiors and reliability improvements, similar to the Class 322 EMUs, which were also refurbished at Kilmarnock.[19]

The units transferred to Arriva Rail North in April 2016, and then Northern Trains on 1 March 2020. With the Class 331s now in service, 3 of the Class 321/9s transferred to Greater Anglia, as an interim measure until their Class 720 fleet is in service, however none of them have operated a service as of 20 June 2020.

First Great Eastern inherited all 66 Class 321/3s and 11 Class 321/4s. The East Anglia franchise was subsequently taken over by National Express East Anglia, initially branded 'one', and then subsequently by Greater Anglia. A further 16 were added, upon release from London Midland. In 2016, 10 of the sets formerly operated by Great Northern also transferred to Greater Anglia.

These trains are primarily used for London Liverpool Street to Braintree, Southend Victoria, Southminster, Ipswich (extending to Norwich during peak time), Walton-on-the-Naze, Clacton-on-Sea and Colchester Town but can be seen running on any electrified route if other trains fail. These operate as 4, 8 or 12 carriage sets.

They have also received 3 Class 321/9s from Northern Trains until the Class 720s enter service, however none of them have entered service as of June 2020.

Silverlink liveried 321425 at Watford Junction

London Midland 321411 at Watford Junction

Silverlink inherited 37 of the 48 Class 321/4 units. In September 2003, Silverlink's class 321 units were temporarily withdrawn following the discovery of loose bolts on brake discs in some units.[20]

In September 2004, London Euston to Birmingham local services were divided into two separate services: Silverlink retained London to Northampton services, while fellow National Express subsidiary Central Trains taking over all local services between Northampton and Birmingham. Initially, Central Trains hired Class 321 units from Silverlink to work their new services, but the arrival of Class 350/1s meant that very few Class 321 units were then required.

To accommodate this sub-lease, three Class 321/3 units were transferred from National Express East Anglia to Silverlink. These were not permitted north of Rugby due to lack of the National Radio Network system (Eastern Region units only had the Cab Secure Radio System used for Driver Only Operated Passenger services) and therefore could not be used on Central Trains services (although they occasionally appeared on services to Rugby at weekends due to the line being closed between Rugby and Birmingham New Street). This ceased in late 2005 with the introduction of Class 350 trains on the Birmingham to Liverpool route. One of these sub-leased units was involved in a low-speed derailment at Watford Yard.[21]

In May 2007, Central Trains began using Class 321 units on some morning services from Birmingham New Street to Walsall.

In November 2007, London Midland took over operation of the Class 321 fleet previously used by Silverlink and Central Trains. An order was placed by London Midland for 37 Class 350/2s to replace the Class 321s.[22]

London Midland withdrew most, retaining seven units (411-417).[23][24] They were used for peak hour workings between London Euston and Northampton and on the Abbey line.[25][26] In 2015 all seven were withdrawn for transfer to Abellio ScotRail to operate on Glasgow suburban lines, with the last withdrawn on 20 September 2015.[13][27] They were replaced by Class 319s.[28][27] Two (413/414) briefly operated for London Overground Rail Operations in late 2015, being revinyled in London Overground livery.[29] The cascaded Class 321s were reformed to three-car units, by removing the TSO vehicle and reclassified as Class 320/4s.[30][13][31] The TSO has been discarded, but one reserve is reserved for Doncaster Wabtec works.[32][33]

First Capital Connect 321420 + 321405 at London King's Cross

First Capital Connect received thirteen units (401-410, 418-420) from London Midland, following deliveries of the new Class 350/2s. The units worked on the Great Northern services from London King's Cross to Peterborough and Cambridge from December 2010 until May 2017. They passed with the franchise to Great Northern in September 2014.

All were replaced in 2016 by Class 387s, cascaded from the Thameslink route.[34] Ten (402, 405-410 and 418-420) moved to Ilford depot for use by Greater Anglia[35] with the remaining three (401, 403, 404) are to be converted to Class 320/4s for Abellio ScotRail.[36]

Northern Trains formerly operated 3 Class 321/9s until these were replaced in 2020 and have transferred to Greater Anglia.

In May 2018 plans were announced to convert some units with Alstom hydrogen cells, giving the acronym HMU (hydrogen multiple unit).[46] A number of this class of train will be converted to hydrogen power and operational by 2022.[47][48] The first concept of this conversion, dubbed "Breeze", was revealed by Alstom and Eversholt Rail in January 2019.[49]