British Rail Class 333

In March 1998, Angel Trains ordered 16 three-carriage sets from Siemens Transportation Systems for Northern Spirit to replace the slam-door Class 308s on the Airedale and Wharfedale lines from Leeds to Bradford Forster Square, Ilkley and Skipton.^[13][14] Construction of the trains was sub-contracted to CAF with Siemens Transportation Systems providing the traction equipment.^[15]

The first was delivered to Neville Hill TMD in March 2000.^[16][17] The first entered service on 12 January 2001.^[18]

In April 2000, a further eight trailer carriages were ordered with funding from West Yorkshire Passenger Transport Executive and inserted into the first eight sets in 2002.^[19][20][21] Subsequently a further order was placed with funding from the Strategic Rail Authority to increase the remaining sets to four carriages.^[22] These were delivered in 2003.^[23]

However, the funding for the fourth carriages in the latter eight sets expired in 2007 and as a consequence of this they could have been removed.^[24][25] Had this happened the four-car Class 321s would have been removed from Leeds to Doncaster services. As a result, the fourth cars were funded by the South Yorkshire Passenger Transport Executive, despite not running in South Yorkshire, to ensure that four-car units are available on Doncaster services.^[26]

In 2008, all were repainted into a new livery by Wabtec at Doncaster Works that incorporated West Yorkshire Metro branding.^[27]

When Arriva Rail North was awarded the Northern franchise in December 2015 plans were announced for the replacement of Class 333 units with a new fleet of 3-car trains,^[28] though ultimately this did not occur.

Between December 2018 and April 2020, all were refurbished by Chrysalis Rail, Holbeck and repainted into Arriva Rail North and later Northern Trains livery.^[29][30][31]

In 2022, the 333s started receiving digital upgrades, and these upgrades include added USB power plugs and Digital display screens among other upgrades.^[32]

The units are capable of 100 mph (160 km/h),^[2][11][33] but the maximum speed on their routes is 90 mph (140 km/h). They have standard class only 2+3 high-density seating, and each set has one toilet.^[9]

Two units have previously carried names:

• 333007 Alderman J Arthur Godwin, First Lord Mayor of Bradford 1907 (De-named)^[34]
• 333011 Olicana, Ilkley's Roman Fort (De-named)^[35]

• 
  Class 333 in the original Northern Spirit livery
• 
  The original interior of a Class 333

• British Rail Class 332, similar units operated by Heathrow Express until 28 December 2020