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 for 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 the 25 kV overhead line. The fleet works inner-suburban services on the Great Eastern Main Line run by the train operating company National Express East Anglia out of London Liverpool Street.

Description
Each Class 315 unit is formed of four vehicles: Driving Motor Standard Open (DMSO), Pantograph Trailer Standard Open (PTSO), Trailer Standard Open (TSO), and Driving Motor Standard Open (DMSO). Each DMSO carries four traction motors (315801-841 originally had Brush TM61-53 and 315842-861 had GEC G310AZ but these motors are interchangeable and nowadays any type can be found on any unit) rated at 110hp each and a main compressor and air reservoir which carries air for the brakes and suspension. The door system which was pneumatic has been replaced by an all electric door system. The PTSO carries the main and auxillery transformers, batteries and battery charger, Stone Faiveley AMBR Mk.1 pantograph, vacuum circuit breaker and auxiliary compressor. The TSO carries no equipment other than that which is standard to all coaches. The coaches only contain standard seating and have no toilet facilities. Car numbering is as follows:
 * 64461-64582 - DMSO
 * 71281-71341 - PTSO
 * 71389-71449 - TSO

Each 4-car set is able to seat 318 passengers. A refurbishment programme commenced from mid 2004, when National Express East Anglia (then 'one' Railway) contracted Bombardier to carry out the refurbishment of all 61 units, starting with the ex-First Great Eastern examples. The low-back 3+2 seating is retained, so the capacity stays the same.

The Class 315 units replaced the life-expired Class 306 units.

Operators
Until 1 April 2004, the fleet was divided between the train operating companies First Great Eastern (43 units) and WAGN (18 units). On that date, 'one' was awarded the new Greater Anglia rail franchise which combined the First Great Eastern and WAGN routes, and so assumed control of all 61 sets. 'one' has since been rebranded National Express East Anglia (NXEA) by its parent company, National Express Group.

Services
The usual duties include:
 *  - 'Metro' 

The Lea Valley Lines
 * '''London Liverpool Street -
 * '''London Liverpool Street -
 * '''London Liverpool Street -

They can occasionally be found further afield, running to Hertford East, Bishop's Stortford, Stansted Airport, Broxbourne, Cambridge, Ely, Southminster, Braintree, Clacton-on-Sea, Colchester, Harwich Town, Walton-on-the-Naze, Ipswich and Southend Victoria, particularly at the peak times.

Class 315s are rumoured to be replaced after the London Olympic Games at Stratford in 2012, as by then they will nearly be life expired (around 2014).

Initially, the Shenfield Metro and Upminster Branch Line services used only sets 315801-843 and the Lea Valley Lines only 315844-861. Presently, however, all 61 sets are used interchangeably.

Since "one" and then National Express have been operating the franchise, it has been less common for 315s to run beyond Shenfield. At present, there are only 2 booked workings beyond Shenfield on Mondays to Fridays. These are:


 * The 06:29 Southend Victoria to London Liverpool Street (arrives 07:29), calling at all stations to Shenfield, then Stratford and Liverpool Street.
 * The 07:21 Southend Victoria to London Liverpool Street (arrives 08:40), calling at all stations to Ilford, then Stratford and Liverpool Street.

Apart from these two workings, 315s are rarely used on services on the Great Eastern Main Line, however can be seen working these routes on occasions, covering for unavailable Class 360s or Class 321s.

Naming
Five Class 315 sets have now been named:
 * 315812 - "London Borough of Newham Host Borough 2012 Olympics Bid" (denamed)
 * 315817 - "Transport for London"
 * 315829 - "London Borough of Havering Celebrating 40 Years"
 * 315845 - "Herbie Woodward"
 * 315857 - "Stratford Connections"