Railway electrification in Great Britain

Railway electrification in Great Britain describes the various electrification systems that are used, or have been used, for supplying traction current to the railways and tramways of Great Britain. The article includes a chronological record of development, and a list of the lines using each system, while for each system a history and a technical description is provided.

History

Railway electrification as a means of traction emerged at the end of the nineteenth century. It offered several benefits over the then predominate steam traction, particularly in respect of its quick acceleration (ideal for urban (metro) and suburban (commuter) services) and power (ideal for heavy freight trains through mountainous/hilly sections). A plethora of systems emerged in the first twenty years of the twentieth century (as listed below). In 1928 a government committee agreed 1500V DC overhead as the national standard, although little work was done to implement this and the plethora of different systems continued to exist (and even expand).

After World War II, with nationalisation (1948), British Rail expanded electrification (1500V DC and the Southern third rail) but soon (mid 1950s) adopted 25 kV AC overhead for its proposed mainline electrification.

Despite the following years of minimal capital investment, the 25 kV AC network has continued to expand, slowly, although large areas of the country are still non-electrified, despite their urban, suburban, hilly or intercity nature.

Facts and Figures

As of 2006, 40% (3,062 miles / 4,928 km) of the British rail network is electrified and 60% of all rail journeys are by electric traction (both by locomotives and multiple units).

According to Network Rail, 64% of the electrified network uses the 25 kV a.c. overhead system and 36% uses the 660/750 V d.c. third rail system.

Systems no longer used

Great Britain has used a number of different electrification systems in the past. Many of these date from the early part of the 20th century when electricity was being experimented with for traction purposes. This section describes each system, in order of increasing voltage.

500V DC, Overhead Line

• Grimsby and Immingham Railway

525V DC, Third Rail

• Liverpool Overhead Railway

The Liverpool Overhead Railway was one of the earliest electric railways in Great Britain. The first section between Alexandra Dock and Herculaneum Dock was opened in 1893. The line connected with Lancashire and Yorkshire Railway's North Mersey Branch. It was never nationalised and it closed on the 30th December 1956 due to extensive corrosion throughout its iron infrastructure (which was deemed uneconomical to replace).

600V DC, Third Rail

• Tyneside Electrics

This was originally electrified in 1904, with an addition in 1938. The line was de-electrified by British Rail in between 1963 and 1967. It now forms the Tyne and Wear Metro and has been re-electrified using a 1500 V d.c., overhead line system (see below).

650V DC, Third Rail

• Swansea and Mumbles Railway

1200V DC, Third Rail (Side-Contact)

A Class 504 (1200V DC) train at Manchester Victoria station just weeks before closure for conversion to the Metrolink light rail system.

• Manchester Victoria - Bury

In 1917 the line between Manchester Victoria and Bury was electrified using a 1200 V d.c. third rail (side contact) system. The line between Bury and Holcombe Brook that had been electrified using 3500 V d.c. overhead system in 1913 was converted to this system in 1918. This system was abandoned in 1991 when the line was converted to a 750 V d.c. overhead system and became part of the Manchester Metrolink. [1] and [2]

1500V DC, Overhead

In the wake of World War I, the British Government set up a committee to investigate the various systems of railway electrification and in 1928 it reported that 1500 V DC overhead should be the future national standard. Several schemes (see below) were implemented in its wake, although the Great Depression and World War II meant very little work was done. Technological advances post-war saw a government U-turn and the 25 kV a.c. system was adopted instead, for the West Coast Main line and Glasgow suburban electrification, as set out in the 1955 BR modernisation plan - at the same time the large amounts of money had/were still being spent converting several lines to 1500 V DC.

• Manchester, South Junction and Altrincham Railway

A joint LMS and LNER effort, opened on the 11th May 1931, it was a test bed for both companies for the new standard (which at the time had not been implemented in the UK) in this largely self-contained busy suburban line.  The success of this scheme propelled LNER's latter electrification efforts.  The line was latter converted to 25 kV a.c. in 1971 but then parts converted to the Manchester Metrolink (a tram system).

• Manchester-Sheffield-Wath

Known as the Woodhead Route. The LNER chose this hilly and busy mainline for its first mainline electrification, with work starting in 1936 [3]. Due to the depression and World War Two it wasn't completed until the 1950's. However upon completion the government chose to utilise 25 kV a.c. instead, leaving the few 1500 V d.c. lines isolated and non-standard. Subsequent rationalisation by BR saw large parts of this route closed east of Hadfield in 1981 (in favour of a route with more local communities). The remaining stub in Manchester was converted to 25 kV a.c. in December 1984.

• Shenfield Metro (Great Eastern Main Line)

Electrified post war (early 1950s), although LNER had been planning this since the early 1930's. It was soon converted to 25 kV a.c., initially with some sections at 6.25 kV a.c., in the wake of the 1955 BR Modernisation plan.

• Shildon to Newport.

This line ran from Shildon (County Durham) to Newport (near Sunderland). In the wake of the electrification of Tyneside by the NER, this coal carrying line was electrified, as a precursor to electrifying NER's busy York to Newcastle mainline (Part of the ECML). It was dismantled by LNER around 1934/1935. [4], [5], [6], [7], [8]

3500V DC, Overhead

• Bury to Holcombe Brook

This was electrified by the Lancashire and Yorkshire Railway in 1913 as part of a trial system for export. The system was converted to third rail in 1918 (see above). [9]

6250V (6.25kV), 50Hz AC, Overhead Line

During the initial electrification of parts of the network to 25 kV, 50 Hz a.c. overhead the initial solution to the limited clearance problems in suburban areas (due to numerous tunnels and bridges) – notably London and Glasgow – was to use the lower voltage of 6.25 kV, 50 Hz a.c. overhead. Latter technological improvements in insulation allowed these area to be converted to 25 kV, 50 Hz a.c. overhead. The last sections of 6.25 kV, 50 Hz a.c. overhead were converted to 25 kV, 50 Hz a.c. overhead in the 1980's and this system of electrification is now obsolete in the UK.

• London, Tilbury and Southend (LTS)
  • The majority of the line was electrified at 6.25 kV a.c. overhead in the early 1960s. Some sections were able to electrified using 25 kV a.c. overhead from the outset. The sections electrified at 6.25 kV a.c. overhead were converted to 25 kV a.c. overhead in the early 1980's.

• Shenfield Metro
  • The line was originally electrified at 1500V d.c. overhead in the 1950's. In the early 1960's the line was converted to 6.25 kV a.c. overhead. In the early 1980's the line was converted for a second time to 25 kV a.c. overhead.

• Glasgow Suburban network
  • The majority of the network was originally electrified at 6.25 kV a.c. overhead in the early 1960s. Some sections were able to electrified using 25 kV a.c. overhead from the outset. The sections electrified at 6.25 kV a.c. overhead were converted to 25 kV a.c. overhead in the early 1980's.
  • North Clyde Line - the central area, Springburn, Bridgeton and Milngavie branches and the Yoker loop)
  • Cathcart Circle Line
  • See SPT and Transport in Glasgow

6600V (6.6 kV), 25 Hz AC, Overhead

• Lancaster to Heysham via Morecambe (Morecambe Branch Line)
• LBSCR's London urban/metro lines

Existing Systems - Conductor Rail Type (Third and Fourth Rails)

600V DC, Third Rail

• Glasgow Subway

This was electrified in 1935.

630V DC, Fourth Rail

The Tube's 4th rail system

• London Underground

650V DC, Third rail

• Merseyrail

A history can be found here. See also "The L&YRS".

660V DC, Third rail

• London and North Western Railway

London suburban network - Euston and Broad Street to Watford Junction, Croxley Green and Richmond ( North London Line and Watford DC Line ). A short history can be found here and [10]. With the advent of Class 313 EMUs the fourth rail was removed on areas not used by LUL stock on the North London Line (NLL). With the closure of Broad Street, the NLL was joined with former Broad Street to North Woolwich via Stratford line, to extend the NLL - this section was electrified for the first time with third rail and OLE as far as Stratford and just third rail to North Woolwich. Two branches off the Watford DC Line have been closed; the branch to Rickmansworth was closed in 1952 (to passengers, goods 1967) and the branch to Croxley Green closed in 1996.

• The Watford DC Line between Queens Park and Harrow & Wealdstone is unusual in that it is used by both Silverlink Metro trains, designed for 750V third rail, and Bakerloo Line trains designed for 630V third and fourth rail. As a compromise the nominal line voltage is set at 660V, and the centre rail is at the same potential as the return running rail, whereas in normal London Underground usage the traction supply floats with the centre rail at nominally -210V and the outer rail at nominally +420V. giving 630V overall.

750V DC, Third rail

An example of a third rail EMU

• Southern Region of British Railways
  • L&SWR / Southern Railway / Southern Region of British Railways - everything but a few freight branches, Marshlink, North Downs Line, Uckfield branch of the Oxted Line, Wessex Main Line, West of England Main Line and Eastleigh to Romsey Line.

• Northern City Line

The Northern City Line connects the East Coast Main Line to Moorgate - It was a former main line taken over by the Underground and turned into a tube line. It was however isolated by the abandonment of the 1930s "New Works" programme (and the development of the greenbelt). Tube services were further truncated by the new Victoria Line in 1964 (which shortened the northern end of the line). The remainder was handed over to BR in 1975 in conjunction with electrification of East Coast Main Line to allow dual voltage (ie both 25kV AC Overhead and Third Rail DC) commuter trains into London. A link with the East Coast Main Line was made to enable this. Presumably third rail was chosen as the tunnels were of too narrow a bore to allow overhead lines to be installed (as they are on the Snowhill, Thameslink route.)

• Docklands Light Railway

This system uses a bottom-contact third rail. The third rail uses a composite conductor rail comprised of an aluminium body with a steel contact surface. The benefit of this is a low-resistance, high current capacity rail that has a durable steel surface for the current collection shoegear of the train.

Existing Systems - Overhead Line (OHL) Type

1500V DC, Overhead

Tyne & Wear Metro is the only current 1500V DC system in the UK

• Tyne and Wear Metro

Despite the abandonment in favour of 25 kV a.c. overhead in the 1950's, large parts of the former "Tyneside Electrics" routes (which had been electrified using third rail until the 1960's when BR discontinued the "non-standard" equipment in favour of diesels) were rebuilt as the "Tyne and Wear Metro" in the 1970's. Styled as "Light Rail" it is in practice normal heavy rail, and even shares some lines with the current rail network (unlike the other tram systems in the UK which operate alongside but on separate rights of way).

25000V (25 kV), 50 Hz AC, Overhead Line

The West Coast Main Line is electrified at 25kV AC Overhead

• London, Tilbury and Southend (LTS)
  • The majority of this line was originally electrified at 6.25kV AC overhead. It was converted to 25kV AC Overhead in the early 1960's.

• Great Eastern Main Line (GEML)
  • Converted from 6.25kV AC overhead and 1500V DC overhead
  • Romford to Upminster Line
  • Shenfield to Southend Line
  • Crouch Valley Line
  • Braintree Branch Line
  • Colchester to Clacton Line
  • Mayflower Line

• West Anglia
  • Originally electrified to Chingford, Enfield Town, Hertford East & Bishops Stortford during the early 1960's.
  • Converted to 25 kV AC overhead in the 1980's
  • Extended from Bishops Stortford to Cambridge in 1987
  • Branch to Stansted Airport opened in 1990
  • Extended from Cambridge to Kings Lynn in 1992

• East Coast Main Line (ECML)
  • Electrified in two parts, the first between 1975 and 1978 and the second between 1984 and 1991.
  • The line between London (Kings Cross) and Royston was electrified between 1976 and 1978 as part of the Great Northern Suburban Electrification Project. This included the Hertford Loop Line.
  • In 1984, authority was given to electrify to Edinburgh and Leeds. The section between Hitchin and Peterborough was completed in 1987, and Doncaster and York were reached in 1989. By 1990 electrification had reached Newcastle, and in 1991 the final section to Edinburgh was completed.
  • In order to keep the construction teams busy two additional schemes were authorised that extended electrification to Carstairs and to North Berwick (North Berwick Line).
  • At the peak of electrification works in the late 1980's it claimed to be the "longest construction site in the world" at over 400 km.

• Midland Main Line (MML)
  • Electrified between London (St Pancras) and Bedford in 1983. The branch from Dock Junction to Moorgate was also electrified.
  • See also Thameslink

• West Coast Main Line (WCML)
  • Electrified from the late 1950s to the mid 1960 under the 1955 BR modernisation plan as far as Crewe (and branches), it was extended to Scotland in the 1970s.
  • Northampton - see Northampton Loop Line
  • Birmingham (New Street) - see Rugby-Birmingham-Stafford Line
  • Liverpool (Lime Street)
  • Manchester (Piccadilly) - see Stafford to Manchester Line and Crewe to Manchester Line.
  • Glasgow (Central) - in 1974 from Weaver Junction.
  • The associated "Abbey Flyer" (St Albans Branch Line) was electrified 1987-88 by Network SouthEast
  • Edinburgh (Waverley) in 1989 (from Carstairs Junction in conjunction with ECML electrification).
  • In 2003 Crewe to Kidsgrove section of the Crewe to Derby Line was electrified as a diversionary route for the WCML.
  • Since 1999 the line has been modernised and the overhead line equipment has undergone a program of refurbishment and renewal as part of works to increase train speeds from 110mph to 125mph.

• Edinburgh
  • 1989 saw the electrification of the ECML which goes through Edinburgh, at the time a few local routes were electrified, but the majority of local services are unelectrified.
  • Edinburgh Crossrail - Only Edinburgh Waverley to Newcraighall, currently the service is by DMUs, pending reopening of part of the Waverley Line
  • North Berwick Line - Edinburgh Waverley to North Berwick, with some extensions to Edinburgh Haymarket.
  • Glasgow to Edinburgh via Carstairs Line - Some North Berwick Line trains continue to Glasgow Central. GNER intercity trains (from the ECML) continue to Glasgow Central.
  • - see also Transport in Edinburgh.

• Glasgow Suburban
  • (see SPT and Transport in Glasgow) - Suburban electrification was started in the 1960s in the wake of the 1955 BR modernisation plan. Electrification was piecemeal over the preceding year and is still incomplete with several suburban, rural and inter city lines still unelectrified. Rail expansion plans call for reopening of the Airdrie-Bathgate Rail Link, connecting the North Clyde Line and Edinburgh to Bathgate Line.
  • Argyle Line - Dalmuir and Milngavie via Glasgow Central (Low Level) to Hamilton Circle, Larkhall, Lanark and Carstairs (via a variety of lines via Hamilton, Motherwell or Holytown). There is also a peak time branch to Coatbridge Central
  • Ayrshire Coast Line - Glasgow Central to Ayr, Largs and Ardrossan Harbour, electrified in 1986/87. See The Rebirth of AyrLine: Electrification to Ayr / Ardrossan / Largs - 1986/1987
  • Cathcart Circle Line - ( Glasgow Central to Newton and Neilston) was electrified on 22nd May 1962
  • Glasgow to Edinburgh via Carstairs Line - Some North Berwick Line trains continue to Glasgow Central. GNER intercity trains (from the ECML) continue to Glasgow Central.
  • Inverclyde Line - (Glasgow Central to Gourock and Wemyss Bay), this was electrified in 1967 .
  • Motherwell to Cumbernauld Line - The Motherwell to Coatbridge section is electrified, but the Coatbridge to Cumbernauld section of the line is not.
  • North Clyde Line - Also known as "Glasgow North Electric Suburban Line", This was one of the first lines in Glasgow to be electrified in 1960. Helensburgh Central, Balloch and Milngavie to Glasgow Queen Street (Low Level) and out to Springburn and Drumgelloch.

• • Paisley Canal Line - Electrified only as far as Corkerhill (from Glasgow Central)

• • Shotts Line - The central section (Holytown Junction to Kirknewton) is not electrified, however both ends are electrified, as they are shared with the WCML, Argyle Line and ECML.

• • Whifflet Line - The section that follows the WCML (Glasgow Central to Rutherglen) is electrified, the rest of the line to Whifflet is not.

• Leeds area
  • Leeds to Skipton (Airedale Line)
  • Leeds to Bradford
  • Leeds to Ilkley (Wharfedale Line)
  • Leeds branch off the ECML (via Wakefield Westgate) (1980s/early 1990s)

• Manchester area -
  • Manchester to Glossop / Hadfield (converted from the truncated 1,500V DC Manchester-Sheffield-Wath electric railway),
  • Manchester, South Junction and Altrincham Railway (although part of this line was converted to the Manchester Metrolink)
  • Manchester Airport Line (although primarily operated by diesel multiple units)
  • Stafford to Manchester Line - branch of WCML, electrifed in the wake of the 1955 BR Modernisation plan.
  • Crewe to Manchester Line - branch of WCML, electrifed in the wake of the 1955 BR Modernisation plan.

• West Midlands area - A few lines out of New Street mainly related to the West Coast Main Line.
  • Trent Valley Line - WCML, 1964.
  • Rugby-Birmingham-Stafford Line - WCML, 1966.
  • Birmingham Cross-City Line - Electrified in the early 1990s, re-opening in 1993.
  • Walsall Line - Electrified from New Street to Walsall.

• Great Western Main Line (GWML)
  • Electrified in 1994 between London Paddington and Heathrow Airport. This scheme was a joint venture between the British Railways Board and the British Airports Authority.
  • See Heathrow Express and Heathrow Connect

• London Crossrail (Proposed)

25-0-25 kV, 50 Hz AC, Overhead Line, Auto-Transformer

• Channel Tunnel Rail Link (CTRL)

The first time that an auto-transformer system has been used in the UK.

• West Coast Main Line (WCML)

Currently in use between Ashton (north of Milton Keynes) and Hillmorton (south of Rugby), but planned to be extended along most of the route between London and Glasgow.

See also

• Railway electrification system
• Railway electric traction
• List of current systems for electric rail traction
• Third Rail
• Overhead Lines
• Suburban electrification of the London, Midland and Scottish Railway
• Manchester-Sheffield-Wath electric railway

External links

• Citytransport.info's Electrification advocacy page
• Kent Rail
• Lancashire & Yorkshire Railway Society
• Southern E Group
• Southern Electric Group
• Suburban Electric Railway Association

Further Reading

525V, d.c., Third Rail

• Box, Charles E. (1959). Liverpool Overhead Railway. Railway World Ltd.
• Gahan, John W. (1992). Seventeen stations to Dingle - The Liverpool Overhead Railway remembered. Countyvise and Avon-Anglia. ISBN 0-907768-20-2.
• Bolger, Paul (1992). The Docker's Umbrella - A History of Liverpool Overhead Railway. The Bluecoat Press. ISBN 1-872568-05-X.
• Jarvis, Adrian (1996). Portrait of the Liverpool Overhead Railway. Ian Allan. ISBN 0-7110-2468-5.

630V, d.c., Fourth Rail

• Glover, John (2003). London's Underground (10th Edition). Ian Allan. ISBN 0 7110 2935 0.

650V, d.c., Third Rail

• Maund, T.B. (2001). Merseyrail Electrics - The Inside Story. NBC Books. ISBN 0-9531896-1-3.

750V, d.c., Third Rail

• Moody, G.T. (1979). Southern Electric 1909-1979. Ian Allan. ISBN 0-7110-0924-4.
• Glover, John (2001). Southern Electric. Ian Allan. ISBN 0-7110-2807-9.

1500V, d.c., Overhead Line

• Appleby, K.C. (1990). Shildon - Newport in Retrospect. ISBN 0-901115-67-3.
• Dixon, Frank (1994). The Manchester South Junction & Altrincham Railway. The Oakwood Press. ISBN 0-85361-454-7.

6600V, 25Hz a.c., Overhead Line

• Goslin, Geoff (2002). London's Elevated Electric Railway - The LBSCR Suburban Overhead Electrification 1909-1929. Connor & Butler Ltd. ISBN 0-947669-35-X.

25kV, 50Hz a.c., Overhead Line

• Nock, O.S. (1966). Britain's New Railway. Ian Allan.
• Nock, O.S. (1974). Electric Euston to Glasgow. Ian Allan. ISBN 0-7110-0530-3.
• Boocock, Colin (1991). East Coast Electrification. Ian Allan. ISBN 0-7110-1979-7.
• Semmens, Peter (1991). Electrifying the East Coast Route. Patrick Stephens Ltd. ISBN 0-85059-929-6.
• Glover, John (2003). Eastern Electric. Ian Allan. ISBN 0-7110-2934-2.