British Rail Class 315

British Rail Class 315 alternating current (AC) electric multiple units (EMU) were built by BREL at York works from 1980 to 1981. They were the fifth and final variety of British Rail's then-standard 1972 design suburban EMUs, which eventually encompassed 755 vehicles and five Classes (Class 313/314/315/507/508). Like the Glasgow-based Class 314 units, they are only able to operate from 25 kV overhead line current collection. The fleet works inner-suburban services on the Great Eastern Main Line run by the train operating company TfL Rail out of London Liverpool Street. Class 315s also did work services from Liverpool Street to Chingford, Enfield Town and Cheshunt operated by London Overground but got discontinued in 2020.

British Rail Class 315
TfL Rail Class 315 at Forest Gate in September 2015
The refreshed interior of a TfL Rail Class 315
In service	1980 – 9 December 2022
Manufacturer	British Rail Engineering Limited
Built at	Holgate Road Works, York
Family name	BREL 1972
Replaced	Class 105 Class 306
Constructed	1980–1981
Refurbishment	All units: 2004–2008 (at Bombardier Derby) LO & TfL Rail units: 2015–2016 (at Bombardier Ilford)
Number built	61
Number preserved	1
Number scrapped	53
Successor	Class 345 Class 710
Formation	4 cars per unit: DMSO-PTSO-TSO-DMSO
Diagram	DMSO vehicles: EA207 PTSO vehicles: EH217 TSO vehicles: EH216
Fleet numbers	315801–315861
Capacity	As built: 318 seats Post-2012: 309 seats, plus 7 tip-up
Operator(s)	British Rail First Great Eastern Greater Anglia London Overground MTR Elizabeth line National Express East Anglia Network SouthEast TfL Rail West Anglia Great Northern
Specifications
Car body construction	Steel underframe with aluminium body and roof
Car length	DM vehs.: 19.800 m (64 ft 11.5 in) Trailers: 19.920 m (65 ft 4.3 in)
Width	2.820 m (9 ft 3.0 in)
Height	3.582 m (11 ft 9.0 in)
Floor height	1.156 m (3 ft 9.5 in)
Doors	Double-leaf pocket sliding, each 1.288 m (4 ft 2.7 in) wide (2 per side per car)
Wheelbase	Over bogie centres: 14.170 m (46 ft 5.9 in)
Maximum speed	75 mph (121 km/h)
Weight	DMSO vehs.: 35.0 t (34.4 long tons; 38.6 short tons) PTSO vehs.: 32.0 t (31.5 long tons; 35.3 short tons) TSO vehs.: 25.5 t (25.1 long tons; 28.1 short tons)
Traction motors	8 total; 4 per DMSO vehicle (Brush TM61-53 or GEC G310AZ, interchangeably)
Power output	660 kW (880 hp)
Acceleration	0.75 m/s2 (2.5 ft/s2)
Train heating	Ducted warm air
Electric system(s)	25 kV 50 Hz AC overhead
Current collection method	Pantograph
UIC classification	Bo′Bo′+2′2′+2′2′+Bo′Bo′
Bogies	BREL BX1
Minimum turning radius	70.4 m (231 ft 0 in)
Braking system(s)	Electro-pneumatic (disc)
Safety system(s)	AWS TPWS
Coupling system	Tightlock
Multiple working	Within class
Track gauge	1,435 mm (4 ft 8 1⁄2 in) standard gauge
Notes
Specifications as at November 1987 except where otherwise noted.