In the 2010s Network Rail modernised the Great Western Main Line , the South Wales Main Line , and other associated lines. The modernisation plans were announced at separate times but their implementation overlapped in the 2010s.
109-444: The work included electrification , resignalling , new rolling stock and station upgrades. The programme began in June 2010 and at that time was due to end in 2017. The project was completed in 2020, allowing electric services to run between London Paddington and Cardiff . The project had several delays. Four sections were deferred indefinitely: The Cardiff to Swansea electrification
218-402: A (nearly) continuous conductor running along the track that usually takes one of two forms: an overhead line , suspended from poles or towers along the track or from structure or tunnel ceilings, or a third rail mounted at track level and contacted by a sliding " pickup shoe ". Both overhead wire and third-rail systems usually use the running rails as the return conductor, but some systems use
327-584: A car park, but will be remodelled as terminating platforms for services to London Paddington. To achieve rail access to the existing old platforms, the Bristol power box, opened in 1970 and controlling 114 route miles of track, will need to be decommissioned and demolished. Bristol Parkway had a new third platform (Platform 4) completed in 2007 to provide a new platform for trains departing to London and Birmingham and to make services more reliable between London and south Wales . A new fourth platform has been built on
436-425: A cycle path. There will be improvements that will provide capacity for at least four extra trains in each direction every hour. The station received: These plans provide for the future Crossrail and possible Airtrack services at Reading station, building a railway that will be fit for at least the next thirty years. Also, the improvements will allow six new freight trains each day – this could take around 300 lorries
545-732: A day off the roads. While much of the work was carried out in 2010, trains to Devon and Cornwall ran from London Waterloo instead of Paddington, using the South Western Main Line via Basingstoke then the West of England Main Line and Wessex Main Lines . Trains to Bristol, South Wales and Cheltenham were diverted via the Chiltern Main Line (from London to Banbury) where they reversed and returned via Oxford to Didcot Parkway, South Oxfordshire to re-adopt
654-573: A higher total efficiency. Electricity for electric rail systems can also come from renewable energy , nuclear power , or other low-carbon sources, which do not emit pollution or emissions. Electric locomotives may easily be constructed with greater power output than most diesel locomotives. For passenger operation it is possible to provide enough power with diesel engines (see e.g. ' ICE TD ') but, at higher speeds, this proves costly and impractical. Therefore, almost all high speed trains are electric. The high power of electric locomotives also gives them
763-467: A historical concern for double-stack rail transport regarding clearances with overhead lines but it is no longer universally true as of 2022 , with both Indian Railways and China Railway regularly operating electric double-stack cargo trains under overhead lines. Railway electrification has constantly increased in the past decades, and as of 2022, electrified tracks account for nearly one-third of total tracks globally. Railway electrification
872-513: A new Crossrail station was to be built under London Paddington , serving as a connection to National Rail services and London Underground. Services were due to start in 2018. Railway electrification system Railway electrification is the use of electric power for the propulsion of rail transport . Electric railways use either electric locomotives (hauling passengers or freight in separate cars), electric multiple units ( passenger cars with their own motors) or both. Electricity
981-428: A new multi-story car park and a new bus station will be developed outside, replacing the existing Newport bus station . The new north and south concourses opened on 13 September 2010. The development was criticised by Rail columnist Barry Doe for being at the wrong end of the station, having a leaking roof, a lack of seating and generally poor design. Extra platform capacity at Cardiff Central will be introduced in
1090-524: A number of European countries, India, Saudi Arabia, eastern Japan, countries that used to be part of the Soviet Union, on high-speed lines in much of Western Europe (including countries that still run conventional railways under DC but not in countries using 16.7 Hz, see above). Most systems like this operate at 25 kV, although 12.5 kV sections exist in the United States, and 20 kV
1199-454: A power grid that is delivered to a locomotive, and within the locomotive, transformed and rectified to a lower DC voltage in preparation for use by traction motors. These motors may either be DC motors which directly use the DC or they may be three-phase AC motors which require further conversion of the DC to variable frequency three-phase AC (using power electronics). Thus both systems are faced with
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#17328586135971308-498: A relative lack of flexibility (since electric trains need third rails or overhead wires), and a vulnerability to power interruptions. Electro-diesel locomotives and electro-diesel multiple units mitigate these problems somewhat as they are capable of running on diesel power during an outage or on non-electrified routes. Different regions may use different supply voltages and frequencies, complicating through service and requiring greater complexity of locomotive power. There used to be
1417-481: A separate fourth rail for this purpose. In comparison to the principal alternative, the diesel engine , electric railways offer substantially better energy efficiency , lower emissions , and lower operating costs. Electric locomotives are also usually quieter, more powerful, and more responsive and reliable than diesel. They have no local emissions, an important advantage in tunnels and urban areas. Some electric traction systems provide regenerative braking that turns
1526-469: A series of 12 commissionings, Invensys Rail would re-lock the existing Reading Station and Spur interlockings to three new WESTLOCK interlocking units, re-control the remaining 18 relay interlockings, and move signalling and telecommunications control from Reading Station to the new Thames Valley Signalling Centre at Didcot. The work was due to be completed in December 2010. The Thames Valley signalling centre
1635-610: A team of around 250 people. The company is an approved railway contractor for in the United Kingdom, Sweden and Norway. Windhoff manufactures specialised rail vehicles including the diesel freight multiple unit the CargoSprinter , and the Windhoff MPV , used for infrastructure and service trains, as well as electric and diesel shunting machines, shunting locomotives, and stationary shunting equipment. The company also manufactures
1744-418: A third rail. The key advantage of the four-rail system is that neither running rail carries any current. This scheme was introduced because of the problems of return currents, intended to be carried by the earthed (grounded) running rail, flowing through the iron tunnel linings instead. This can cause electrolytic damage and even arcing if the tunnel segments are not electrically bonded together. The problem
1853-400: A train to check the installation. The system was expected to be able to install 1.5 kilometres (0.93 mi) of electrification in an eight-hour shift. The vehicles were supplied by German firm Windhoff . In its initial survey, Network Rail identified 113 structures – mainly bridges and tunnels – which required modernisation. In subsequent surveys this increased to 137. The largest structure,
1962-542: Is a German manufacturer of specialised railways rolling stock, and heavy industrial plant. The company was founded in 1889. The company is well known for its CargoSprinter rail vehicle, and derivatives. The company started out as the Rheiner Maschinenfabrik (Machine Factory of Rheine) in Rheine near Münster, Germany in 1889 manufacturing machines for the weaving industry and founded by Rudolf Windhoff. By 1901
2071-585: Is because of the deferment of the electrification project. Despite the initial limit of 125 mph, the increased acceleration and operational efficiency are expected to decrease the journey time from London to Bristol Temple Meads by 22 minutes. These new trains bring an estimated 15% increased capacity during the morning peak hours. The bi-mode trains will allow inter-city services to operate from London directly to locations in South Wales and South West England, to which electrification does not extend under
2180-411: Is derived by using resistors which ensures that stray earth currents are kept to manageable levels. Power-only rails can be mounted on strongly insulating ceramic chairs to minimise current leak, but this is not possible for running rails, which have to be seated on stronger metal chairs to carry the weight of trains. However, elastomeric rubber pads placed between the rails and chairs can now solve part of
2289-663: Is designed to allow Adjacent Line Operation (ALO) where works can be carried out while trains operate on adjacent tracks. The HOPS has five sections, each of which handles a different aspect of the installation – these can be coupled together to work as one unit, or separated to work independently. The train will be maintained at the High Output Operations Base (HOOB) in Swindon , on the site of former sidings. HOPS will mix and lay 30 m (1,100 cu ft) of concrete per night, and all equipment and personnel will arrive at
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#17328586135972398-451: Is effected by one contact shoe each that slide on top of each one of the running rails . This and all other rubber-tyred metros that have a 1,435 mm ( 4 ft 8 + 1 ⁄ 2 in ) standard gauge track between the roll ways operate in the same manner. Railways and electrical utilities use AC as opposed to DC for the same reason: to use transformers , which require AC, to produce higher voltages. The higher
2507-526: Is electrified, companies often find that they need to continue use of diesel trains even if sections are electrified. The increasing demand for container traffic, which is more efficient when utilizing the double-stack car , also has network effect issues with existing electrifications due to insufficient clearance of overhead electrical lines for these trains, but electrification can be built or modified to have sufficient clearance, at additional cost. A problem specifically related to electrified lines are gaps in
2616-486: Is limited and losses are significantly higher. However, the higher voltages used in many AC electrification systems reduce transmission losses over longer distances, allowing for fewer substations or more powerful locomotives to be used. Also, the energy used to blow air to cool transformers, power electronics (including rectifiers), and other conversion hardware must be accounted for. Standard AC electrification systems use much higher voltages than standard DC systems. One of
2725-755: Is no longer exactly one-third of the grid frequency. This solved overheating problems with the rotary converters used to generate some of this power from the grid supply. In the US , the New York, New Haven, and Hartford Railroad , the Pennsylvania Railroad and the Philadelphia and Reading Railway adopted 11 kV 25 Hz single-phase AC. Parts of the original electrified network still operate at 25 Hz, with voltage boosted to 12 kV, while others were converted to 12.5 or 25 kV 60 Hz. In
2834-447: Is sufficient traffic, the reduced track and especially the lower engine maintenance and running costs exceed the costs of this maintenance significantly. Newly electrified lines often show a "sparks effect", whereby electrification in passenger rail systems leads to significant jumps in patronage / revenue. The reasons may include electric trains being seen as more modern and attractive to ride, faster, quieter and smoother service, and
2943-410: Is that the power-wasting resistors used in DC locomotives for speed control were not needed in an AC locomotive: multiple taps on the transformer can supply a range of voltages. Separate low-voltage transformer windings supply lighting and the motors driving auxiliary machinery. More recently, the development of very high power semiconductors has caused the classic DC motor to be largely replaced with
3052-850: Is the countrywide system. 3 kV DC is used in Belgium, Italy, Spain, Poland, Slovakia, Slovenia, South Africa, Chile, the northern portion of the Czech Republic, the former republics of the Soviet Union , and in the Netherlands on a few kilometers between Maastricht and Belgium. It was formerly used by the Milwaukee Road from Harlowton, Montana , to Seattle, across the Continental Divide and including extensive branch and loop lines in Montana, and by
3161-565: Is the development of powering trains and locomotives using electricity instead of diesel or steam power . The history of railway electrification dates back to the late 19th century when the first electric tramways were introduced in cities like Berlin , London , and New York City . In 1881, the first permanent railway electrification in the world was the Gross-Lichterfelde Tramway in Berlin , Germany. Overhead line electrification
3270-420: Is typically generated in large and relatively efficient generating stations , transmitted to the railway network and distributed to the trains. Some electric railways have their own dedicated generating stations and transmission lines , but most purchase power from an electric utility . The railway usually provides its own distribution lines, switches, and transformers . Power is supplied to moving trains with
3379-834: Is used on some narrow-gauge lines in Japan. On "French system" HSLs, the overhead line and a "sleeper" feeder line each carry 25 kV in relation to the rails, but in opposite phase so they are at 50 kV from each other; autotransformers equalize the tension at regular intervals. Various railway electrification systems in the late nineteenth and twentieth centuries utilised three-phase , rather than single-phase electric power delivery due to ease of design of both power supply and locomotives. These systems could either use standard network frequency and three power cables, or reduced frequency, which allowed for return-phase line to be third rail, rather than an additional overhead wire. The majority of modern electrification systems take AC energy from
Great Western Main Line upgrade - Misplaced Pages Continue
3488-760: The ATP (Automatic Train Protection) warning system was under trial. In response to that incident, it became a requirement for all First Great Western trains to be fitted with ATP. When the Department for Transport wrote the specification for the new trains for the IEP in November 2007, it was stated that the Great Western Main Line would be upgraded to ERTMS / ETCS level 2 in-cab signalling and trackside infrastructure. Some or all of
3597-638: The Delaware, Lackawanna and Western Railroad (now New Jersey Transit , converted to 25 kV AC) in the United States, and the Kolkata suburban railway (Bardhaman Main Line) in India, before it was converted to 25 kV 50 Hz. DC voltages between 600 V and 750 V are used by most tramways and trolleybus networks, as well as some metro systems as the traction motors accept this voltage without
3706-626: The HSL-Zuid and Betuwelijn , and 3,000 V south of Maastricht . In Portugal, it is used in the Cascais Line and in Denmark on the suburban S-train system (1650 V DC). In the United Kingdom, 1,500 V DC was used in 1954 for the Woodhead trans-Pennine route (now closed); the system used regenerative braking , allowing for transfer of energy between climbing and descending trains on
3815-471: The Hitachi A-train family. The "Intercity 125" trains, now operating in shortened formations on services around Cardiff, Bristol, Exeter and Plymouth are one of the fastest trains on the network with the ability to operate at up to 125 mph (201 km/h). The new AT300 units have a top speed of 125 mph but will be capable of 140 mph (225 km/h) with minor modifications. The upgrading of
3924-481: The Hitachi Super Express trains could reduce journey times from London Paddington to Swansea by 19 minutes. In an effort to minimise disruption during the electrification works, Network Rail developed new "factory engineering trains" to facilitate the process of installing overhead lines. There are three types of train: the first train to install pylons, followed by a train to hang the wires and finally
4033-674: The Innovia ART system. While part of the SkyTrain network, the Canada Line does not use this system and instead uses more traditional motors attached to the wheels and third-rail electrification. A few lines of the Paris Métro in France operate on a four-rail power system. The trains move on rubber tyres which roll on a pair of narrow roll ways made of steel and, in some places, of concrete . Since
4142-838: The Midland Main Line were the last of the major main line routes in the UK using diesel as the main source of locomotive power. When the announcement was made in July 2009 to electrify the Great Western (along with the Liverpool-Manchester line ), it represented the first big rail electrification project in the UK for 20 years. The South Wales Main Line section of the GWML was set to be the first electrified cross-country railway line in Wales. The plan to upgrade
4251-624: The Newport area, Cardiff and Port Talbot West. The first phase of the Newport Area remodelling and resignalling began in 2009 and was expected to be completed by the end of 2010. The first phase covered the line between Patchway and Marshfield to the west of Newport. A new South Wales Control Centre, built on the eastern end of Canton Depot in Cardiff, opened in Spring 2009. When the Newport Area resignalling
4360-655: The Severn Tunnel , has good clearances and is relatively easy to electrify. After the 2010 UK general election in May 2010, the Conservative–Liberal Democrat coalition placed all major government capital expenditure, including the Great Western electrification scheme on hold pending a return-on-investment review. In November 2010, Transport Secretary Philip Hammond gave the go-ahead for the lines from Oxford via Didcot to London and Newbury to London to be electrified in
4469-616: The Southern Railway serving Coulsdon North and Sutton railway station . The lines were electrified at 6.7 kV 25 Hz. It was announced in 1926 that all lines were to be converted to DC third rail and the last overhead-powered electric service ran in September 1929. AC power is used at 60 Hz in North America (excluding the aforementioned 25 Hz network), western Japan, South Korea and Taiwan; and at 50 Hz in
Great Western Main Line upgrade - Misplaced Pages Continue
4578-454: The United States , the New York, New Haven and Hartford Railroad was one of the first major railways to be electrified. Railway electrification continued to expand throughout the 20th century, with technological improvements and the development of high-speed trains and commuters . Today, many countries have extensive electrified railway networks with 375 000 km of standard lines in
4687-679: The 1930s. Later, a bomb destroyed the manufacturing premises on 5 October 1944. In 1957 the company stopped manufacturing normal locomotives and start to concentrate on tracking machines ( ballast tampers ). The Windhoff company was first listed on the stock exchange in 1993. On 19 December 2001, the main company was declared bankrupt and the industrial plant and railway engineering divisions being taken over on 1 March 2002, to become part of Georgsmarienhütte Holdings GmbH. The Windhoff division, as Windhoff Bahn- und Anlagentechnik GmbH (Windhoff Railway- and Equipment Technology) continues to supply specialist railway vehicles and infrastructure with
4796-636: The 1970s Plymouth PSB, and the 1960s PSB at Gloucester as well as substantial semaphore signalling in Cornwall. The first phase of a £400M, ten-year resignalling scheme in South Wales by Network Rail was carried out on a 22-mile (35 km) stretch between Port Talbot and Bridgend (termed Port Talbot East) in 2006 and 2007. The works provided a new turnback facility in both directions at Port Talbot Parkway if required. The renewals replaced an old British Railways Western Region NX panel installation, dating from 1963. Further signalling renewals were programmed for
4905-568: The 387 units replacing the 165 and 166 units on these services, services which previously locally from Paddington to Oxford now operate short to Didcot Parkway due to the electrification not running on the Cherwell Valley Line between Didcot and Oxford. It was originally planned that Class 365 Networker trains, electric versions of the Class 165/166s previously operated by Govia Thameslink Railway , would cascade from Great Northern services to
5014-524: The Elizabeth Line when opened in 2022, runs in part on the Great Western line. It has 70 Class 345 trains which are formed of 9 carriages and can carry 1,500 passengers. These electric multiple units can achieve speeds of up to 90 mph (140 km/h) on the surface sections of the route and up to 60 mph (97 km/h) in the tunnels. These trains were built by Bombardier Transportation at its Derby Litchurch Lane Works . Several stations along
5123-427: The Great Western Main Line. As of February 2015, the regeneration and modernisation of Reading Station is complete. The station now has 15 platforms, each serving their own specialist destination and purpose. The new platforms allow more frequent trains to run through Reading and allow more passengers to join longer trains. The entire Reading Redevelopment project will be completed by 2017. An improvement programme for
5232-413: The Great Western are undergoing redevelopment or have recently been upgraded to cope with growing passenger numbers and to ease rail traffic congestion. Bristol Temple Meads will be expanded into Digby Wyatt's 1870s extension to the original train shed, built by Isambard Kingdom Brunel in 1840 as the terminus for the Great Western Main Line. This part of the 'Old Station' building is currently in use as
5341-546: The Great Western between London Paddington and Bristol Temple Meads in a first phase, then electrifying the rest of the line between Swindon and Swansea at a later date. However, in July 2009, the Department of Transport under the then Labour Government (in the run-up to the 2010 general election ), announced that there would be a £1bn programme to electrify the whole of the Great Western from London to Swansea as well as to Bristol Temple Meads. The Labour government claimed that
5450-684: The Netherlands, New Zealand ( Wellington ), Singapore (on the North East MRT line ), the United States ( Chicago area on the Metra Electric district and the South Shore Line interurban line and Link light rail in Seattle , Washington). In Slovakia, there are two narrow-gauge lines in the High Tatras (one a cog railway ). In the Netherlands it is used on the main system, alongside 25 kV on
5559-471: The Thames Valley, but this did not go ahead as planned and the units remained in operation with Govia Thameslink until their withdrawal in 2021. The 387 units replacing the 165 and 166 units has allowed most of the units to be transferred to St Philip's Marsh depot for use on services in the Bristol and South West area (see Bristol Metro scheme below). The western section of Crossrail, which became known as
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#17328586135975668-582: The UK, the London, Brighton and South Coast Railway pioneered overhead electrification of its suburban lines in London, London Bridge to Victoria being opened to traffic on 1 December 1909. Victoria to Crystal Palace via Balham and West Norwood opened in May 1911. Peckham Rye to West Norwood opened in June 1912. Further extensions were not made owing to the First World War. Two lines opened in 1925 under
5777-494: The ability to pull freight at higher speed over gradients; in mixed traffic conditions this increases capacity when the time between trains can be decreased. The higher power of electric locomotives and an electrification can also be a cheaper alternative to a new and less steep railway if train weights are to be increased on a system. On the other hand, electrification may not be suitable for lines with low frequency of traffic, because lower running cost of trains may be outweighed by
5886-516: The advantages of raising the voltage is that, to transmit certain level of power, lower current is necessary ( P = V × I ). Lowering the current reduces the ohmic losses and allows for less bulky, lighter overhead line equipment and more spacing between traction substations, while maintaining power capacity of the system. On the other hand, the higher voltage requires larger isolation gaps, requiring some elements of infrastructure to be larger. The standard-frequency AC system may introduce imbalance to
5995-483: The autumn". The report stated that costs had tripled from the £874M original estimate to £2.8bn, and was £1.2bn higher than the estimate made a year ago. The main part of the programme will go ahead as planned and should be delivered by March 2019, but the Cardiff to Swansea section will be delayed, to some time between 2019 and 2024. Revised dates for the completion of electrification work were published in early 2016, with electrification to Cardiff via Bristol Parkway, and
6104-564: The company was employing over 100 people. As similar control mechanisms were used for steam-driven automated weaving looms and for stream-driven railway traversers and turntables , Rudolf Windhoff also founded the Motoren- und Fahrzeugfabrik Gebr. Windhoff (Windhoff Brothers' Engine and Vehicle Factory). In 1913, these two private companies were combined to form the share-based Rheiner Maschinenfabrik Windhoff (Windhoff Machine Factory Rheine). This combined company suffered losses during
6213-538: The connection to Newbury planned by December 2018; the branch to Oxford from Didcot by June 2019; and the branch to Bristol Temple Meads from Wootton Bassett sometime between February 2019 and April 2020. In November 2016, the government announced that electrification work on the sections from Oxford to Didcot Parkway, Bristol Parkway to Bristol Temple Meads, Thingley Junction (near Chippenham ) to Bath Spa and Bristol Temple Meads, and branches lines to Henley and Windsor had been indefinitely deferred. For Oxford and Bristol,
6322-476: The conventional at-grade crossing of the 'Mains' lines via points, with the aim of alleviating delays due to slow-moving freight services passing through the station. By 2014 the total cost had risen to more than £800M. As well as the reconfiguration of the track, the terminal platforms for services to/from London Waterloo will be altered and the Cow Lane bridge under the tracks has been made two-way and now includes
6431-568: The current electrification proposals, like Carmarthen , Worcester , Gloucester , Cheltenham and the regions to the southwest of Bristol and Newbury. Majority of the fleet are Class 800 units deferred from the Intercity Express Programme which run alongside the Class 802 units, which are essentially a more powerful variant of the Class 800 which are able to cope better with the gradients in Devon and Cornwall. New servicing facilities for
6540-531: The deferral was due to imminent resignalling and remodelling of the existing track layout. In July 2017, it was announced that the Cardiff-Swansea electrification project had been cancelled and that bi-mode trains would be used on the route. The Great Western Main Line was equipped with colour light signalling common to the rest of the United Kingdom. At the time of the Ladbroke Grove rail crash (1999),
6649-410: The distance they could transmit power. However, in the early 20th century, alternating current (AC) power systems were developed, which allowed for more efficient power transmission over longer distances. In the 1920s and 1930s, many countries worldwide began to electrify their railways. In Europe, Switzerland , Sweden , France , and Italy were among the early adopters of railway electrification. In
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#17328586135976758-448: The electrification. Electric vehicles, especially locomotives, lose power when traversing gaps in the supply, such as phase change gaps in overhead systems, and gaps over points in third rail systems. These become a nuisance if the locomotive stops with its collector on a dead gap, in which case there is no power to restart. This is less of a problem in trains consisting of two or more multiple units coupled together, since in that case if
6867-404: The end of funding. Most electrification systems use overhead wires, but third rail is an option up to 1,500 V. Third rail systems almost exclusively use DC distribution. The use of AC is usually not feasible due to the dimensions of a third rail being physically very large compared with the skin depth that AC penetrates to 0.3 millimetres or 0.012 inches in a steel rail. This effect makes
6976-520: The expected passenger traffic associated with the 2010 Ryder Cup . A new passenger bridge and two new terminal buildings were constructed, with each platform being served by a lift. The new bridge is clad in ethylene tetrafluoroethylene (ETFE), the material which protects the Eden Project in Cornwall , despite which the roof initially gave problems with leaking. The new development at the station includes
7085-571: The experiment was curtailed. In 1970 the Ural Electromechanical Institute of Railway Engineers carried out calculations for railway electrification at 12 kV DC , showing that the equivalent loss levels for a 25 kV AC system could be achieved with DC voltage between 11 and 16 kV. In the 1980s and 1990s 12 kV DC was being tested on the October Railway near Leningrad (now Petersburg ). The experiments ended in 1995 due to
7194-500: The fact that electrification often goes hand in hand with a general infrastructure and rolling stock overhaul / replacement, which leads to better service quality (in a way that theoretically could also be achieved by doing similar upgrades yet without electrification). Whatever the causes of the sparks effect, it is well established for numerous routes that have electrified over decades. This also applies when bus routes with diesel buses are replaced by trolleybuses. The overhead wires make
7303-407: The forecourt of Didcot Parkway began in September 2012 and ran for two years. Features included: In 2018, a new multi-storey car park was built at Didcot Parkway, on the site of the original car park. It provides 1800 spaces to cater for the station's role as a park and ride facility for the surrounding area. In 2009, an upgrade to Newport station was started to enable the station to cope with
7412-465: The form of a new bay platform (platform 5) for services between Cardiff and Maesteg along the GWML and one new through platform to the south of the station (platform 8) for the Cardiff urban services to cater for up to 16 trains per hour. This will bring the number of platforms from 7 to 10. Redevelopment of Cardiff Central bus station outside the railway station commenced in 2008. Between 2009 and 2015,
7521-1012: The general power grid. This is especially useful in mountainous areas where heavily loaded trains must descend long grades. Central station electricity can often be generated with higher efficiency than a mobile engine/generator. While the efficiency of power plant generation and diesel locomotive generation are roughly the same in the nominal regime, diesel motors decrease in efficiency in non-nominal regimes at low power while if an electric power plant needs to generate less power it will shut down its least efficient generators, thereby increasing efficiency. The electric train can save energy (as compared to diesel) by regenerative braking and by not needing to consume energy by idling as diesel locomotives do when stopped or coasting. However, electric rolling stock may run cooling blowers when stopped or coasting, thus consuming energy. Large fossil fuel power stations operate at high efficiency, and can be used for district heating or to produce district cooling , leading to
7630-411: The high cost of the electrification infrastructure. Therefore, most long-distance lines in developing or sparsely populated countries are not electrified due to relatively low frequency of trains. Network effects are a large factor with electrification. When converting lines to electric, the connections with other lines must be considered. Some electrifications have subsequently been removed because of
7739-406: The investment would pay for itself over a 40-year period. The scheme announced by the government on 23 July 2009 stated that "work will begin immediately on the electrification of the Great Western Main Line between London, Reading , Oxford , Newbury , Bristol , Cardiff and Swansea, to be completed within eight years" (2016/2017). The proposed electrified route included: Estimates showed that
7848-492: The losses (saving 2 GWh per year per 100 route-km; equalling about €150,000 p.a.). The line chosen is one of the lines, totalling 6000 km, that are in need of renewal. In the 1960s the Soviets experimented with boosting the overhead voltage from 3 to 6 kV. DC rolling stock was equipped with ignitron -based converters to lower the supply voltage to 3 kV. The converters turned out to be unreliable and
7957-422: The maximum power that can be transmitted, also can be responsible for electrochemical corrosion due to stray DC currents. Electric trains need not carry the weight of prime movers , transmission and fuel. This is partly offset by the weight of electrical equipment. Regenerative braking returns power to the electrification system so that it may be used elsewhere, by other trains on the same system or returned to
8066-402: The need for overhead wires between those stations. Maintenance costs of the lines may be increased by electrification, but many systems claim lower costs due to reduced wear-and-tear on the track from lighter rolling stock. There are some additional maintenance costs associated with the electrical equipment around the track, such as power sub-stations and the catenary wire itself, but, if there
8175-832: The new fleet have been developed at the London North Pole Depot , the Filton Triangle rail depot in Stoke Gifford and at Maliphant sidings in Swansea. Thames Valley commuter services from London Paddington to Reading and Didcot Parkway are all operated by a fleet of 33 Class 387 four-car 110 mph (177 km/h) trains, having replaced the majority of the Class 165 ‘Networker Turbo’ two or three-car DMUs and Class 166 ‘Networker Turbo Express’ three-car DMUs which are capable of operating at 90 mph (145 km/h). Due to
8284-456: The next six years. Extension from Didcot to Swindon, Bath, Bristol and to South Wales would be dependent on a further assessment due in 2011 of the costs and implementation requirements of the IEP. On 1 March 2011, Hammond announced that rail electrification from Didcot Parkway to Bristol Temple Meads and Cardiff Central would go ahead. The section linking Bristol Parkway and Bristol Temple Meads would also be electrified. In March 2012, Amey plc
8393-497: The phase separation between the electrified sections powered from different phases, whereas high voltage would make the transmission more efficient. UIC conducted a case study for the conversion of the Bordeaux-Hendaye railway line (France), currently electrified at 1.5 kV DC, to 9 kV DC and found that the conversion would allow to use less bulky overhead wires (saving €20 million per 100 route-km) and lower
8502-500: The problem by insulating the running rails from the current return should there be a leakage through the running rails. The Expo and Millennium Line of the Vancouver SkyTrain use side-contact fourth-rail systems for their 650 V DC supply. Both are located to the side of the train, as the space between the running rails is occupied by an aluminum plate, as part of stator of the linear induction propulsion system used on
8611-537: The resignalling work would be carried out alongside the electrification work. Signalling Solutions would resignal the 12 miles from Paddington to West Drayton , including the Airport branch, as part of the Crossrail project. In November 2008, Westinghouse (subsequently known as Invensys Rail, and now part of Siemens Rail Automation) was awarded a £20m contract for a 30-month programme of signalling enabling work. Over
8720-460: The resistance per unit length unacceptably high compared with the use of DC. Third rail is more compact than overhead wires and can be used in smaller-diameter tunnels, an important factor for subway systems. The London Underground in England is one of few networks that uses a four-rail system. The additional rail carries the electrical return that, on third-rail and overhead networks, is provided by
8829-570: The revenue obtained for freight and passenger traffic. Different systems are used for urban and intercity areas; some electric locomotives can switch to different supply voltages to allow flexibility in operation. Six of the most commonly used voltages have been selected for European and international standardisation. Some of these are independent of the contact system used, so that, for example, 750 V DC may be used with either third rail or overhead lines. There are many other voltage systems used for railway electrification systems around
8938-656: The rolling stock on the Great Western was included in the IEP announced in 2007, a Department for Transport (DfT) led initiative to replace the ageing fleet of InterCity 125 and InterCity 225 train sets then in use on much of the UK rail network. Passenger timetables introduced electric running from Paddington to Didcot in January 2018, and to Swindon and as far west as Bristol Parkway in January 2019. The same month saw electric services between Reading and Newbury. Electric running to Newport commenced in December 2019 and to Cardiff in January 2020. The Cardiff to Swansea electrification
9047-490: The running rails. On the London Underground, a top-contact third rail is beside the track, energized at +420 V DC , and a top-contact fourth rail is located centrally between the running rails at −210 V DC , which combine to provide a traction voltage of 630 V DC . The same system was used for Milan 's earliest underground line, Milan Metro 's line 1 , whose more recent lines use an overhead catenary or
9156-464: The same task: converting and transporting high-voltage AC from the power grid to low-voltage DC in the locomotive. The difference between AC and DC electrification systems lies in where the AC is converted to DC: at the substation or on the train. Energy efficiency and infrastructure costs determine which of these is used on a network, although this is often fixed due to pre-existing electrification systems. Both
9265-515: The scope of the project. However, the Marlow electrification has been postponed for the foreseeable future due to difficulties at Bourne End. The new NR Series 1 overhead line equipment, designed and manufactured by Furrer+Frey, is a TSI compliant OLE design specified to allow multiple pantograph operation at 140 mph (230 km/h) operation and is being installed using Amey plc 's High Output Plant System (HOPS) and other conventional techniques. This
9374-505: The service "visible" even in no bus is running and the existence of the infrastructure gives some long-term expectations of the line being in operation. Due to the height restriction imposed by the overhead wires, double-stacked container trains have been traditionally difficult and rare to operate under electrified lines. However, this limitation is being overcome by railways in India, China and African countries by laying new tracks with increased catenary height. Windhoff Windhoff
9483-603: The signalling on the Great Western to in-cab signalling is one pre-requisite to allow the new trains to run at the higher speed. In the 2010 GWML RUS, Network Rail stated that linespeeds in excess of 125 mph west of Reading would be "reviewed in line with electrification and resignalling opportunities as ERTMS becomes deployed across the RUS area" after Control Period 4 (2014–2019). The new AT300 units now used on Great Western inter-city services are bi-modal units that are capable of running on lines with and without overhead wires. This
9592-689: The site on board. The HOPS train was operational by 2014, but had not reached full productivity due to teething problems . By 2015, completion of the electrification project had been delayed, reportedly 1 year behind schedule, with completion expected in 2017. Costs of the electrification were reported to have tripled from an estimated £640M to £1.74bn. In June 2015, the International Railway Journal reported: "Britain's secretary of state for transport, Mr Patrick McLoughlin has asked Sir Peter Hendy to review Network Rail's 2014–2019 capital investment programme, known as CP5 , and report back in
9701-459: The south side of the station. On 10 September 2008, Network Rail unveiled a £400M regeneration and reconfiguration of Reading station and surrounding track, incorporating an overpass to the west of the station; with freight and passenger trains able to transit from the Reading to Taunton Line and Reading to Basingstoke Line to the 'Relief' lines via an underpass beneath the 'Mains' lines, replacing
9810-555: The steep approaches to the tunnel. The system was also used for suburban electrification in East London and Manchester , now converted to 25 kV AC. It is now only used for the Tyne and Wear Metro . In India, 1,500 V DC was the first electrification system launched in 1925 in Mumbai area. Between 2012 and 2016, the electrification was converted to 25 kV 50 Hz, which
9919-443: The supply grid, requiring careful planning and design (as at each substation power is drawn from two out of three phases). The low-frequency AC system may be powered by separate generation and distribution network or a network of converter substations, adding the expense, also low-frequency transformers, used both at the substations and on the rolling stock, are particularly bulky and heavy. The DC system, apart from being limited as to
10028-694: The three-phase induction motor fed by a variable frequency drive , a special inverter that varies both frequency and voltage to control motor speed. These drives can run equally well on DC or AC of any frequency, and many modern electric locomotives are designed to handle different supply voltages and frequencies to simplify cross-border operation. Five European countries – Germany, Austria, Switzerland, Norway and Sweden – have standardized on 15 kV 16 + 2 ⁄ 3 Hz (the 50 Hz mains frequency divided by three) single-phase AC. On 16 October 1995, Germany, Austria and Switzerland changed from 16 + 2 ⁄ 3 Hz to 16.7 Hz which
10137-575: The through traffic to non-electrified lines. If through traffic is to have any benefit, time-consuming engine switches must occur to make such connections or expensive dual mode engines must be used. This is mostly an issue for long-distance trips, but many lines come to be dominated by through traffic from long-haul freight trains (usually running coal, ore, or containers to or from ports). In theory, these trains could enjoy dramatic savings through electrification, but it can be too costly to extend electrification to isolated areas, and unless an entire network
10246-466: The train stops with one collector in a dead gap, another multiple unit can push or pull the disconnected unit until it can again draw power. The same applies to the kind of push-pull trains which have a locomotive at each end. Power gaps can be overcome in single-collector trains by on-board batteries or motor-flywheel-generator systems. In 2014, progress is being made in the use of large capacitors to power electric vehicles between stations, and so avoid
10355-713: The train's kinetic energy back into electricity and returns it to the supply system to be used by other trains or the general utility grid. While diesel locomotives burn petroleum products, electricity can be generated from diverse sources, including renewable energy . Historically, concerns of resource independence have played a role in the decision to electrify railway lines. The landlocked Swiss confederation which almost completely lacks oil or coal deposits but has plentiful hydropower electrified its network in part in reaction to supply issues during both World Wars. Disadvantages of electric traction include: high capital costs that may be uneconomic on lightly trafficked routes,
10464-413: The transmission and conversion of electric energy involve losses: ohmic losses in wires and power electronics, magnetic field losses in transformers and smoothing reactors (inductors). Power conversion for a DC system takes place mainly in a railway substation where large, heavy, and more efficient hardware can be used as compared to an AC system where conversion takes place aboard the locomotive where space
10573-470: The tyres do not conduct the return current, the two guide bars provided outside the running ' roll ways ' become, in a sense, a third and fourth rail which each provide 750 V DC , so at least electrically it is a four-rail system. Each wheel set of a powered bogie carries one traction motor . A side sliding (side running) contact shoe picks up the current from the vertical face of each guide bar. The return of each traction motor, as well as each wagon ,
10682-432: The voltage, the lower the current for the same power (because power is current multiplied by voltage), and power loss is proportional to the current squared. The lower current reduces line loss, thus allowing higher power to be delivered. As alternating current is used with high voltages. Inside the locomotive, a transformer steps the voltage down for use by the traction motors and auxiliary loads. An early advantage of AC
10791-405: The weight of an on-board transformer. Increasing availability of high-voltage semiconductors may allow the use of higher and more efficient DC voltages that heretofore have only been practical with AC. The use of medium-voltage DC electrification (MVDC) would solve some of the issues associated with standard-frequency AC electrification systems, especially possible supply grid load imbalance and
10900-532: The world, and the list of railway electrification systems covers both standard voltage and non-standard voltage systems. The permissible range of voltages allowed for the standardised voltages is as stated in standards BS EN 50163 and IEC 60850. These take into account the number of trains drawing current and their distance from the substation. 1,500 V DC is used in Japan, Indonesia, Hong Kong (parts), Ireland, Australia (parts), France (also using 25 kV 50 Hz AC ) ,
11009-527: The world, including China , India , Japan , France , Germany , and the United Kingdom . Electrification is seen as a more sustainable and environmentally friendly alternative to diesel or steam power and is an important part of many countries' transportation infrastructure. Electrification systems are classified by three main parameters: Selection of an electrification system is based on economics of energy supply, maintenance, and capital cost compared to
11118-560: Was awarded a £700 million contract to undertake the electrification works. In July 2012, the UK Government announced that the final portion of the Great Western from Cardiff to Swansea would be electrified. In addition, as part of the Electric Spine project, the line between Reading and Basingstoke would also be electrified at 25kV AC OHL. The overhead electrification of the branches to Henley, Marlow and Windsor were also added to
11227-409: Was cancelled in 2017. Under the Intercity Express Programme (IEP), 21 electric Class 801 trains were ordered as replacements for the ageing InterCity 125 diesels. In May 2016 it was confirmed that the new trains would be built as 'bi-mode' Class 800s instead, meaning they can run on either diesel power or electric overhead wire. At the start of the 21st century, the Great Western Main Line and
11336-589: Was completed in 2011, the Newport signalbox would be closed. Control would pass to the South Wales Control Centre for other parts of the South Wales network as resignalling progressed. Until May 2019, services from London Paddington to South West England and South Wales were served by Class 43 "InterCity 125" train sets. The Intercity 125 trains were built between 1975 and 1982 and due to their age were replaced by Class 800 and Class 802 "AT300" units from
11445-437: Was exacerbated because the return current also had a tendency to flow through nearby iron pipes forming the water and gas mains. Some of these, particularly Victorian mains that predated London's underground railways, were not constructed to carry currents and had no adequate electrical bonding between pipe segments. The four-rail system solves the problem. Although the supply has an artificially created earth point, this connection
11554-543: Was first applied successfully by Frank Sprague in Richmond, Virginia in 1887-1888, and led to the electrification of hundreds of additional street railway systems by the early 1890s. The first electrification of a mainline railway was the Baltimore and Ohio Railroad's Baltimore Belt Line in the United States in 1895–96. The early electrification of railways used direct current (DC) power systems, which were limited in terms of
11663-405: Was formally abandoned in 2017. As of 2023, the electrification of Didcot to Oxford has yet to happen, after being delayed until track modification and station remodelling at Oxford. Prior to 2009, the only electrified portion of the Great Western was between London Paddington and Airport Junction (west of Hayes and Harlington ). This portion is equipped with a 25 kV AC overhead system which
11772-568: Was implemented in 1997 in readiness for the Heathrow Express service commencing in early 1998. Electrification was extended from Airport Junction to Maidenhead under the Crossrail scheme. Further electrification west of Maidenhead was announced by the DfT separately, though the work west of Airport Junction (to take Crossrail to Maidenhead) and west of Maidenhead is likely to be undertaken as one scheme. The UK government first considered electrifying
11881-401: Was to eventually replace older signalling control in the entire English Western region. The London area was due to switch over at the end of 2011, followed by the old Slough PSB ( Power Signal Box ) area. Attention would then be given to abolishing Oxford, Swindon A, Bristol PSBs and the 1990s Swindon B IECC . This would be followed by the elimination of the 1980s PSBs at Westbury and Exeter, and
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