British Rail Class 345

British Rail Class 345
*Aventra*
British Rail Class 345; Aventra
	Class 345 unit at Abbey Wood
	Interior of a Class 345 unit
In service	22 June 2017 – present
Manufacturers	Bombardier Transportation; Alstom;
Built at	Derby Litchurch Lane Works
Family name	Aventra
Replaced	Class 315; Class 360;
Constructed	2015–2019 (first batch); 2025–present (second batch);
Number under construction	10
Number built	70
Formation	9 cars per unit; (See § Fleet details)
Fleet numbers	345001–345070
Capacity	1500 total (454 seated, 1046 standing)
Owner	345 Rail Leasing
Operators	Current: GTS Rail Operations; Former: MTR Elizabeth line; TfL Rail;
Depots	Ilford EMU (London); Old Oak Common (London);
Lines served	GEML (Liverpool Street to Shenfield); GWML (Paddington to Heathrow and Reading); Elizabeth line (Paddington to Abbey Wood and Stratford);
Specifications
Car body construction	Aluminium, with steel cabs
Train length	204.73 m (671 ft 8 in)
Car length	DM vehs.: 23.615 m (77 ft 5.7 in); Others: 22.500 m (73 ft 9.8 in);
Width	2.772 m (9 ft 1.1 in)
Height	3.760 m (12 ft 4.0 in)
Floor height	1.145 m (3 ft 9.1 in)
Doors	Double-leaf sliding plug,; each 1.450 m (4 ft 9.1 in) wide; (3 per side per car)
Wheel diameter	825–750 mm (32.5–29.5 in) (new–worn)
Wheelbase	Per bogie:; 2.25 m (7 ft 5 in); Over bogie centres:; 16.00 m (52 ft 6 in);
Maximum speed	90 mph (145 km/h)
Weight	319 tonnes (314 long tons; 352 short tons);
Traction motors	20 × 250 kW (340 hp); (2 per powered bogie) (IGBT-VVVF)
Power output	4,400 kW (5,900 hp) (at rail)
Acceleration	1 m/s2 (3.3 ft/s2)
Electric system	25 kV 50 Hz AC overhead
Current collection	Pantograph
UIC classification	2′Bo′+2′Bo′+Bo′Bo′+2′Bo′+2′2′+Bo′2′+Bo′Bo′+Bo′2′+Bo′2′
Bogies	Bombardier FLEXX Eco 5011
Braking systems	Electro-pneumatic (disc) and regenerative
Safety systems	AWS; CBTC (Siemens Trainguard); ETCS; TPWS;
Coupling system	Dellner
Track gauge	1,435 mm (4 ft 8+1⁄2 in) standard gauge
Notes/references
	Sourced from unless otherwise noted.

The British Rail Class 345 Aventra is a fleet of electric multiple unit passenger trains built by Bombardier Transportation (now Alstom) for use on London's Elizabeth line. Part of Bombardier's Aventra family of trains, the contract for their delivery was awarded as part of the Crossrail project in February 2014. A total of 70 nine-car units – each able to carry 1,500 passengers – were constructed in Derby between 2015 and 2019, at a cost of over £1 billion. The first unit entered service on 22 June 2017.

A further ten units were ordered in June 2024, for delivery in 2026, which will take the total fleet size to 80.