page_title: 21st-century modernisation of the Great Western main line
section_title: Review and announcements after May 2010 general election
hierarchical_section_title: 21st-century modernisation of the Great Western main line / Electrification / Review and announcements after May 2010 general election
caption_attribution_description: English: A Network Rail High Output Plant System (HOPS) with vehicle DR76922 in the lead. This is based at Swindon for engineering work to install the Great Western Main Line Electrification but is seen here at Creech St Michael on the approach to Taunton.
context_page_description: Network Rail plans to spend £5 billion on modernising the Great Western main line, its South Wales branch and other associated lines. The modernisation plans were announced at separate times but their development time-scales overlap in the 2010s. The work includes electrification, resignalling, new rolling stock and station upgrades. According to Network Rail, the modernisation started in June 2010 and was due to end in 2017. As of December 2019, electrification was complete as far west as Cardiff Central, and also from Reading to Newbury.
  The project has been subject to repeated delays. In November 2016 the government announced that several major elements of the electrification programme would be indefinitely deferred because costs had tripled. The five sections that are delayed are:
  Oxford to Didcot Parkway
  Bristol Parkway to Bristol Temple Meads
  Thingley Junction, near Chippenham, to Bath Spa and Bristol Temple Meads
  Thames Valley branches to Henley and Windsor
  Swansea to Cardiff.
  Under the Intercity Express Programme, 21 electric Class 800 trains were ordered as replacements for the ageing InterCity 125 diesels.
context_section_description: 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 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 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 25 kV AC OHL. The overhead electrification of the branches to Henley, Marlow and Windsor were also added to 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 operation and is being installed using Amey plc's High Output Plant System (HOPS) and other conventional techniques. This 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 m³ (1,100 cu ft) of concrete per night, and all equipment and personnel will arrive at 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.
caption: A High Output Plant System train
exif: {"Image Make": "Canon", "Image Model": "Canon EOS 500D", "Image Orientation": "Horizontal (normal)", "Image DateTime": "2016:11:24 12:07:54", "Image Artist": "", "Image YCbCrPositioning": "Co-sited", "Image Copyright": "", "Image ExifOffset": "2248", "GPS GPSVersionID": "[2, 2, 0, 0]", "Image GPSInfo": "12388", "Image XPAuthor": "[0, 0]", "Image Padding": "[]", "EXIF ExposureTime": "1/500", "EXIF FNumber": "5", "EXIF ExposureProgram": "Shutter Priority", "EXIF ISOSpeedRatings": "400", "EXIF ExifVersion": "0221", "EXIF DateTimeOriginal": "2016:11:24 12:07:54", "EXIF DateTimeDigitized": "2016:11:24 12:07:54", "EXIF ComponentsConfiguration": "YCbCr", "EXIF ShutterSpeedValue": "9", "EXIF ApertureValue": "37/8", "EXIF ExposureBiasValue": "-1/3", "EXIF MeteringMode": "Pattern", "EXIF Flash": "Flash did not fire, compulsory flash mode", "EXIF FocalLength": "38", "EXIF SubSecTime": "27", "EXIF SubSecTimeOriginal": "27", "EXIF SubSecTimeDigitized": "27", "EXIF FlashPixVersion": "0100", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "3456", "EXIF ExifImageLength": "2304", "Interoperability InteroperabilityVersion": "[48, 49, 48, 48]", "EXIF InteroperabilityOffset": "12352", "EXIF FocalPlaneXResolution": "576000/149", "EXIF FocalPlaneYResolution": "2304000/593", "EXIF FocalPlaneResolutionUnit": "2", "EXIF CustomRendered": "Normal", "EXIF ExposureMode": "Auto Exposure", "EXIF WhiteBalance": "Auto", "EXIF SceneCaptureType": "Standard", "EXIF Padding": "[]", "EXIF OffsetSchema": "4168"}