British Rail Class 701

British Rail Class 701
Arterio
Class 701 ‘Arterio’ at Kingston
Interior of a Class 701
In service9 January 2024 – present
Manufacturers
Built atDerby Litchurch Lane Works
Family nameAventra
Replaced
Constructed2019–2024
Number built90
Number in service30 (as of December 2025)
Formation
  • 10 cars per 701/0 unit
  • 5 cars per 701/5 unit
(See § Fleet details)
Fleet numbers
  • 701/0: 701001–701060
  • 701/5: 701501–701530
Capacity
  • 701/0: 556 seats
  •  plus 746 standees
  • 701/5: 274 seats
  •  plus 361 standees
OperatorSouth Western Railway
Depots
Lines served
Specifications
DoorsDouble-leaf sliding plug (2 per side per car)
Maximum speed100 mph (160 km/h)
Traction systemBombardier IGBT Inverter
Traction motors
  • 701/0: 16x 250kW (335hp)
  • 701/5: 8x 250kW (335hp)
Power output
  • 701/0: 4000kW (5364hp)
  • 701/5: 2000kW (2682hp)
Acceleration
  • Maximum current:
  • Starting: 0.96 m/s2 (3.1 ft/s2)
  • Reduced current:
  • Starting: 0.7 m/s2 (2.3 ft/s2)
Deceleration0.9 m/s2 (3.0 ft/s2)
Electric systems750 V DC third rail
Current collectionContact shoe
BogiesFlexx B5000
Braking systemsElectro-pneumatic (disc) and rheostatic/regenerative
Safety systems
Coupling systemDellner
Multiple workingWithin subclass /5 only
Track gauge1,435 mm (4 ft 8+12 in) standard gauge

The British Rail Class 701 Arterio is a class of electric multiple unit passenger train built by Bombardier Transportation and Alstom at Derby Litchurch Lane Works. Built on the Aventra platform, they are operated by South Western Railway, and operate services between Waterloo and Windsor, Reading, Staines and South West London suburban lines.

Ordered in 2017, the trains were originally due to enter service from mid-2019, but were subject to several delays which prevented this. SWR began their phased entry into service from January 2024. They will eventually allow the withdrawal of SWR's fleets of Class 455 units and the cascade of the Class 458 fleet to longer-distance services.