In 1987 British Rail was extending electrification north from London Liverpool Street towards Cambridge. Included in this plan was the construction of new branch line, diverging from the main line at Stansted Mountfitchet, to serve the newly built, which opened in 1991. BR decided to build a dedicated fleet of units to work a new service called Stansted Express. To reduce costs the Class 322 units were built to the same basic design as the successful Class 321 units, which were still under construction for services on the Great Eastern Main Line and West Coast Main Line. Although the Stansted route fell under the jurisdiction of Network SouthEast, the units were delivered into service in a special white livery with a broad green band, instead of the more usual NSE blue/red/white livery. The units are fitted with Tightlock couplers. This allows them to work in multiple with,,,, and units, as well as other units of the same class. Five 4-car units were built, numbered 322481–485. Each unit consisted of two outer driving trailers, an intermediate trailer and an intermediate motor coach. The technical description of the formation of each unit is DTCO+TSO+MSO+DTSO. Individual vehicles are numbered as follows:
78163–78167 – DTCO
72023–72027 – TSO
63137–63141 – MSO
77985–77989 – DTSO
The units were the last of a long line of BR multiple units to be based on the Mark 3 bodyshell design.
Current operations
Northern Trains
The Class 322s operate services with Northern Trains and are used to provide services between Leeds and Doncaster as well as the Airedale and Wharfedale lines between Leeds, Skipton, Bradford and Ilkley. Small technical changes have been made in order for them to be used in the area. These include forward-facing CCTV and saloon CCTV installation and electronic LED destination displays and automatic GPS based announcing system. In early 2016, under previous operator Arriva Rail North, it was confirmed that Spanish rolling stock manufacturer CAF were to construct the new electric Class 331 trains which are planned to operate in West Yorkshire to replace Class 321 and Class 322 trains and work alongside the current fleet of Class 333 units.
Following privatisation, the fleet passed into control of the West Anglia Great Northern franchise. At the same time, services were rebranded as the Stansted Skytrain. Units continued to be used on these services until 1997, when they became common-user with the rest of the WAGN fleet. After this, it was common for units to turn up on London King's Cross to Peterborough services. Four of the five units were subsequently hired to North Western Trains. However, on return to WAGN, they did not have any specific duties to work, as dedicated rebuilt Class 317/7 units were introduced to the Stansted Airport services in 2000. The Class 322 fleet therefore remained non-standard in WAGN's fleet, so in 2001 all five units were hired to ScotRail, who operated similar Class 320 units. The class was transferred north to Scotland in two batches under their own power, routed via the West Coast Main Line.
'One'
, or One, operated a set from 2004. In late 2005 the set was transferred to First ScotRail.
In the period 1997 to 1999, North Western Trains hired four units from WAGN for a new Manchester Airport to London Euston service. These services did not last long, and by 1999 the units had returned to WAGN.
First ScotRail
From 2001 the units – having been made redundant on WAGN services – were used by First ScotRail, operating on the North Berwick Branch Line, between / and North Berwick. They were transferred north to Scotland and were put to work allowing the elderly incumbent Class 305 slam-door units to be withdrawn. One morning and one evening peak service were provided to Glasgow Central via the relatively quiet Edinburgh–Carstairs branch of the WCML to allow the units to receive maintenance at Glasgow Shields depot as First ScotRail's facilities in Edinburgh are for diesel traction only. The units continued to be used on these services until mid-2004, when the hire period ended. They were transferred south in two batches, and were replaced on the North Berwick branch by EWSClass 90 electric locomotives hauling former Virgin Trains Mk.3 coaching stock. To enable trains to reverse the locomotive operated in push-pull mode with a Driving Van Trailer. In mid- to late-2005 the units were transferred back to Scotland for refurbishment prior to reintroduction on the North Berwick line, which was expected to be their permanent use. In Spring 2006, the first unit to be refurbished and repainted in the First ScotRail livery was unveiled. The units were refurbished at Hunslet-Barclay, Kilmarnock, between 16 July 2005 and 9 February 2007. 322481 was the first one repainted, and it took the name that 322485 carried when the class previously operated the route. The remaining units were refurbished and repainted into First ScotRail livery. However, one unit, no. 322481, was named North Berwick Flyer, 1850–2000. In 2010, with the introduction of Class 380 "Desiro", the North Berwick Line saw a fleet replacement which began operations in June 2011. The last service operated by a Scotrail Class 322 was the 0756 North Berwick–Glasgow Central service on 2 August 2011. All five units were transferred to Northern Rail in December.
