British Rail Class 313
A refreshed First Capital Connect Class 313 No. 313027 calls at Grange Park on the Hertford Loop Line.
Refreshed interior aboard a First Capital Connect Class 313
Specifications
Car length	20.33 m
UIC classification	Bo-Bo + 2-2 + Bo-Bo
Bogies	BX1

Class 313 electric multiple units were built by BREL at York Works between February 1976 and April 1977 and were the first second-generation EMUs to be constructed for British Rail. They were also the first British Rail units fitted with both a pantograph for 25kV AC overhead lines and shoegear for 750V DC third rail supply,^[1][2] and the first units in Britain to have fully automatic couplers, which allow both physical coupling and also the connection of control electric and air supplies to be carried out without the need to leave the cab.

Description

The Class 313 fleet was developed following extensive trials with the prototype Class 445 "PEP" unit built in the early 1970s. The 313 is similar to its sister classes of Class 314, Class 315, Class 507 and Class 508 which are used in Glasgow, East London and Merseyside respectively.

Since they were originally designed for use on Great Northern Suburban Inner Suburban services from Moorgate to Welwyn Garden City or Hertford North, which included a section of 'tube' line built to take standard size trains between Drayton Park and Moorgate, they are built to a slightly smaller loading gauge than conventional trains. They are standard length and width, but the roof is somewhat lower, most noticeable due to the lack of a distinctive "well" for the Stone Faiveley AMBR pantograph on the centre coach. Also, they have to comply with regulations for underground trains, such as having doors at each end of the train for evacuation onto the tracks, and when on 750 V DC supply, the traction supply for each motor coach is separate, whereas on conventional 750V DC trains each coach in a unit is linked by a 750V bus line. Due to this, each motor coach has shoe gear on both bogies, whereas normally it would only be provided on the leading bogie. They are also fitted with trip-cocks which are struck by a raised train-stop arm at red signals and will apply the brakes if the train passes one.

The three-car units were originally numbered in the range 313001-064. Each unit is formed of two outer driving motors, and an intermediate trailer equipped with a pantograph. This is a reversal of the practice started in the 1960s where the motors and if applicable pantograph would be carried on an intermediate vehicle, with the outer vehicles being un-powered driving trailers. Part of the reason was to simplify the equipment to allow dual voltage operation, and to keep down weight by spreading heavy equipment (the transformer and motors) between vehicles. The intermediate trailer carries the pantograph and also a transformer and rectifier, which when on 25kV AC supply provides a 750 V DC supply to the motor coaches, each of which is equipped with four 110 hp GEC G310AZ traction motors, two per bogie. When on 750 V DC supply, each motor coach draws its supply directly through its shoe gear.

The Class 313s are fitted with Series Wound DC GEC G310AZ traction motors, which are controlled by a camshaft controlled resistance system, with series and parallel motor groupings and weak field steps. During the winter, the heating in the motor coaches is provided by passing air over the hot traction and braking resistors, as well as conventional heaters. First Capital Connect units are also in the process of being retro-fitted with cab air conditioning equipment.

Class 313s are fitted with rheostatic braking (disabled on London Overground) in addition to conventional 3 step air-operated disc braking, during braking if wheelslide is detected by the WSP (WheelSlide Protection) rheostatic braking is disabled and the disc-braking comes into effect. Additionally units operated by First Capital Connect are equipped with sanding equipment. Unlike some other classes of DMU/EMU additional brake force is not available when the an emergency brake application is initiated and is the equivalent force of a step 3/full service application, however WSP is disabled when making an emergency application.

In addition to the primary suspension (formed of dampers), secondary suspension is provided by air 2 air bellows per bogie, the air flow into each bellow is controlled independently by a levelling valve and arm assemby which will allow the suspension to inflate/deflate when the weight of the coach is increased or decreased by passenger loading. The air suspension system is also linked to the braking system via a Variable Load Valve (VLV), this will give an increase in air brake pressure when the coach is more heavily loaded to compensate for the additional weight.

The DMS B coach is equipped with an MA set (Motor Alternator) which runs on 750V DC from the AC/DC changeover switch whereby the transformer and rectifier provide the supply when on 25kV working and by the shoegear directly when on 3rd rail working. The MA provides power for the following equipment:

• 415V - Headlight, battery charger, resistor cooling fan, coach lighting, coach heater fans (the heaters themselves run on 750V DC).
• 240V - Cab heater fan, CCTV system, appliance sockets.

Individual vehicles are numbered as follows.^[3]

• 62529-62592 - DMSO^[3]
• 71213-71276 - PTSO^[3]
• 62593-62656 - BDMSO^[3]

All units have standard class seating only.^[3]

As built, the sliding doors of these units were individually opened by the passengers. Once the driver had stopped the train and the guard had activated the master door release, a passenger could move the door handle gently sideways which would operate a switch controlling the individual door opening circuit. Unfortunately many people did not wait for the guard's release, and gave the handle a much harder tug, which could open the door even if the train had not stopped. Concerns over passenger safety led to the removal of the handles from March 1977.^[4] In recent years, push-buttons have been fitted which serve the same purpose as was intended for the handles.

Modifications led to a certain amount of renumbering and reclassification. All 64 units were originally provided with shoebeams on the inner bogie of each motor coach, which was sufficient for their original third-rail duties between Drayton Park and Moorgate. Some units became surplus, and four were transferred to the Colchester-Clacton/Walton route, which has no DC sections; these four units had the shoegear removed, and were renumbered from 313061-4 to 313096-9.^[5] 16 others had shoegear fitted to the outer bogies in addition, and were transferred to the Euston-Watford route where there are long gaps in the conductor rails; these, 313001-016, were not renumbered,^[6] but were classified 313/1, the unmodified units becoming 313/0 - prior to this the entire class were simply designated class 313, without subdivisions.

Current operations

Following privatisation, the Class 313 fleet was divided between two franchises - Silverlink and West Anglia Great Northern (WAGN)

First Capital Connect

West Anglia Great Northern inherited the majority of the class, with a fleet of 41 units operating inner suburban services out of Moorgate and London King's Cross, to Welwyn Garden City, Hertford North, Letchworth Garden City and Stevenage. Although the majority of the route is 25 kV AC through overhead cables the line between Moorgate and Drayton Park is third rail DC only (the line was formerly part of the Northern Line and although built to full loading gauge there is insufficient clearance to add catenary). Trains bound for Moorgate arrive at Drayton Park drawing power via the pantograph. At Drayton Park the driver presses a single button that lowers the pantograph and completes all the necessary electrical switching to proceed on DC power. On journeys from Moorgate the procedure is reversed again at Drayton Park. They can occasionally be found further afield, running to places such as Peterborough or Kings Lynn

From 1 April 2006, the Great Northern (GN) franchise merged with Thameslink to form the Thameslink/Great Northern franchise, which was won by First Capital Connect.

An additional three^[7] 313/1 units are expected to transfer to First Capital Connect from London Overground as the new Class 378 Capitalstars enter service in 2009-2010 to augment the existing Class 313/0 fleet operating inner suburban services from King's Cross and Moorgate.

London Overground

Silverlink inherited a fleet of 23 units, mainly operated as Silverlink Metro services on the North London, West London and Watford DC Lines and they were regulars on the St. Albans Abbey–Watford Junction branch line between 1988 and 2006, when the Silverlink franchise ended.

In 2007, these trains were used on services transferred to London Overground, which replaced the Silverlink Metro franchise. London Overground branding was added, and some seats were removed to provide additional standing room. They are now being replaced by Class 378 Capitalstar trains, which feature longitudinal seating to improve standing room. Thirteen Class 313 trains have been withdrawn from London Overground services.^{[citation needed][when?]}

The final day of Class 313 operation on the North and West London Lines was 19 February 2010.^{[citation needed]} As of March 2010^[update], Class 313 trains continue on the Watford DC Line while the Class 378 Capitalstars are prepared for Driver Only Operation.

Southern

Twenty Class 313s displaced by Class 378 Capitalstars on London Overground services are being transferred to Southern, where they will replace Class 377/3 Electrostars on East and West Coastway services from Brighton.^[8] This decision is controversial, as the 377s are much newer than the 313s and have more on-board passenger facilities^[9].

These Class 313 trains are being overhauled and refurbished at Wolverton works.^[when?] This includes a new exterior livery and will eventually include new flooring, new seating and the fitting of a Passenger Information System.^{[citation needed]} Additional modifications are also taking place at Battersea Stewarts Lane TMD including the installation of cab air-conditioning, sanding equipment, a 750V busline, shore supply sockets and the removal of inboard shoegear.^{[citation needed]} These modifications will eventually be integrated with the overhauls at Wolverton.^{[citation needed]} Recommissioning exams are currently^[when?] taking place at Stewarts Lane, which include the removal of tripcocks.^{[citation needed]}

Since January 2010, units 313101, 313108 and 313109 have been providing driver training in rotation as a six-car formation, with single units leaving for Stewarts Lane TMD as required for scheduled maintenance.^{[citation needed]} The first three 313s in Southern livery were released from Wolverton Works in February 2010 and are now berthed at Stewarts Lane TMD, awaiting recommissioning and modifications.^{[citation needed]} These units are being renumbered into the 313/2 series to differentiate them from London Overground configuration.^{[citation needed]}

Unit 313206, released from Wolverton on 14 April 2010, was the first to boast Coastway branding, promoting the lines the 313s are intended to run on as, "Your local links along the South Coast", with local pictures and a list of destinations.^{[citation needed]}

Fleet details

Gallery

• 
  313020 at London Kings Cross. 313s were occasionally used for parcel services out-of-hours. Jan 1982
• 
  The first Class 313 EMU, 313001 is seen at Watford Junction in Network SouthEast livery. Late 1980s
• 
  WAGN unit 313064 at London Kings Cross in a white livery advertising London's Family Travelcard. Feb 2003
• 
  First Capital Connect's 313033 at Stevenage, still in WAGN's purple livery but with FCC branding. Apr 2006
• 
  First Capital Connect No. 313051 at the rear of a six car northbound service to Welwyn Garden City, is seen departing New Southgate Aug 2008
• 
  Silverlink 313107 at Clapham Junction with a service from Willesden Junction on the West London Line. Oct 2004
• 
  London Overground 313123 passes through Hackney Central on its way to Stratford. 313s are being replaced on the North London Line by Class 378 units. Aug 2009

Notes

References

• Haresnape, Brian; Swain, Alec (1989). 10: Third Rail DC Electric Multiple-Units. British Rail Fleet Survey. Shepperton: Ian Allan. ISBN 0 7110 1760 3. {{cite book}}: Invalid |ref=harv (help)
• Pritchard, Robert; Fox, Peter; Hall, Peter (2009). British Railways Locomotives & Coaching Stock 2009. Sheffield: Platform 5 Publishing. ISBN 1 902336 70 4. {{cite book}}: Invalid |ref=harv (help)

Further reading

• Vaughan, Adrian (2003). "Class 313". Railway Blunders. Hersham: Ian Allan. pp. 102–103. ISBN 0 7110 2836 2. 0309/B3. {{cite book}}: Unknown parameter |month= ignored (help)