Electrification: Challenges and timescales

One of the big rail-related questions posed since last May’s general election has been whether or not the coalition would support further electrification of the network. Since the spending review, it seems that existing proposals remain largely intact although some doubt has been cast over the extent to which the Great Western Main Line will be electrified. January is likely to see a Department for Transport (DfT) statement on the long-distance train fleet and this will have a significant bearing.

This article covers only the schemes proposed for England (and possibly Wales); those in Scotland appear unaffected, with Airdrie-Bathgate opening last month and the Edinburgh Glasgow Improvement Programme still on track.

DfT and Network Rail agenda

The possibility of further electrification was first raised by the then Labour government back in 2008. This led Network Rail to undertake some preliminary work on behalf of the DfT. The document, Britain’s Transport Infrastructure: Rail Electrification was published by the department in July 2009, confirming government support for a programme in England and Wales – this encompassed the Great Western Main Line to Bristol, Oxford, Newbury, Cardiff and Swansea, and Liverpool-Manchester via Chat Moss. Funding would be provided by Network Rail through an increase in the regulatory asset base to the value of £1.3 billion.

The DfT also indicated its intention to review the cost and benefits of other schemes. To the annoyance of some East Midlands MPs who were expecting a positive decision on the Midland Main Line beyond Bedford, a surprise announcement was made in December 2009 to support the electrification of further routes in the north-west. These consist of Manchester Victoria to Euxton Junction (near Preston), Huyton Junction to Wigan and Preston to Blackpool which, along with the Liverpool-Manchester route, have been collectively entitled ‘the Lancashire triangle’.

The case for electrification as set out in the DfT document considers the likely continued rising price of oil, the need for carbon reductions and increased use of sustainable energy. These factors have resulted in the business and environmental cases for further electrification on some routes becoming positive, with the proviso that the capital cost is kept affordable. Electric trains use power generated at source and will therefore contribute increasingly to a greener environment as UK electricity generation moves towards more sustainable forms, with consequential reductions in carbon emissions. Specifically, the document noted that electrification has the following advantages over other forms of traction –

•        electric trains emit up to 30% less carbon than their diesel equivalents

•        maintenance costs for electric trains are up to 33% lower

•        savings on fuel costs of up to 50% can be made

•        savings of up to 20% in leasing costs can be made when electrification on particular routes coincides with rolling stock cascade or replacement

•        the capital cost of electric trains is less than their diesel equivalents

•        electrification brings the potential for reduced journey times, more seats per vehicle and improved levels of train availability and reliability.

In October 2009, following the publication of the DfT document, Network Rail published its own Electrification Route Utilisation Strategy (RUS) which advocated a rolling programme of wiring to cover a substantial part of the network. At its core, this proposal included the Midland Main Line, Great Western Main Line and two infill schemes of strategic importance – namely Gospel Oak to Barking and Liverpool to Manchester. Other routes included for future work included the trans-Pennine and Cross Country networks, extension of the GWML to Plymouth and a number of add-on routes such as Crewe-Chester and the Windermere branch. The Electrification RUS also considered other benefits such as the integration of route clearance work for the strategic freight network into the electrification programme where more efficient delivery opportunities might be adopted.

Of the schemes supported by the DfT, completion dates showed electrification between Liverpool and Manchester being ready by 2012, Bristol by 2016 and Swansea by 2017. Since these were first published last July, the position on electric rolling stock has become clouded. Firstly, the proposed cascade of some Class 319s to the north-west is likely to be late due to delays in the procurement of the new Thameslink fleet. Similarly for the Great Western, the replacement of the HST by IEP is currently on hold whilst the concept and offer from Agility Trains – IEP’s preferred bidder – is reconsidered on a value for money basis. According to Philip Hammond, Transport Secretary, the result of this work should be known “early in the New Year”. The rolling stock position has already driven back those completion dates.

Electrification workers
Electrification work is carried out by engineers

Initial development work

In the latter half of 2009, Network Rail began to develop plans for the electrification of the GWML and north-west routes by undertaking a number of detailed surveys and feasibility studies. The purpose of this work has been to establish key areas of cost, develop programmes and delivery strategies. A number of important areas will have been considered including –

•        The type of proposed electrification system and associated fault current levels – in other words, a classic system with booster transformers or the use of auto-transformers. The choice will determine the potential feeder supply spacing and allow identification of potential grid or DNO (Distribution Network Operator) supply locations.

•        Surveys of all structures to identify which are foul of electrification gauge and identify proposed solutions such as bridge reconstruction, track slewing or lowering. It should be noted that utility and service diversions on certain bridges can be a significant cost which may, under certain circumstances, favour lowering the track as opposed to raising the structure.

•        Immunisation costs for signalling and telecommunication equipment. The extent of the work needed will vary from route to route, depending on the age and type of existing equipment. Recent resignalling schemes are generally thought to have been renewed with modern 25kV-immune equipment, but this may not always be the case.

•        Cost effective OLE, distribution and protection & control equipment, and the suitability and price of existing products. The need to develop new, more cost-effective and technologically advanced designs was also identified, where appropriate.

•        A delivery strategy – the minimisation of possessions, associated train operator compensation and the use of high output installation methods including the type of plant available.

•        Consents – the consequence of electrification on areas of historical importance and the need to find sympathetic electrification solutions for places such as Bristol, Bath and Rainhill.

•        The implications of Technical Standards for Interoperability legislation, the purpose of which is to harmonise the European railway system, making infrastructure and rolling stock compatible on a pan-European basis for interoperability. Quite how this will be achieved within the constraints of the UK railway environment remains to be seen.

Progress on the Great Western

A decision on whether the Great Western’s wires will be extended beneath the Severn into Wales is likely soon. Work involving the DfT and Welsh Assembly government has been ongoing in a bid to confirm the business case for them to reach Swansea, as was originally envisaged. It has already been confirmed that the sections of route serving London commuter traffic – those reaching Newbury, Didcot and Oxford – will definitely go ahead.

For the GWML, Network Rail is believed to be proposing the use of an auto-transformer system with an increase in the UK standard fault level current from 6kA to 12kA, thus allowing greater distances between electricity supply points. It is understood that detailed development work is now being undertaken by the National Grid to establish possible sites.

In addition, a full route survey has been carried out which will have included analysis of all the bridges, tunnels and other features. Issue 65 (March 2010) featured an article by Severn Partnership which described surveying the Severn Tunnel using the point cloud laser system. It is understood that the tunnel has sufficient clearance for the wires although management of water ingress would be a major consideration.

The delivery strategy being developed for the Great Western is thought to be focussing on installing OLE during midweek night possessions, while keeping the railway partially operational with trains running on adjacent tracks. This approach will demand solutions to some major challenges including development of suitable OLE supporting structures as well as procuring specialist plant that will ensure the safety of the workforce.

Liverpool to Manchester

Network Rail is also believed to be making significant progress on the Liverpool to Manchester electrification, with outline designs for the OLE and structure clearance now underway. The first possessions for bridge reconstruction are believed to have been booked, with the physical works scheduled to start in May. In light of the current rolling stock position, the eastern section of the route is being prioritised because Class 350s are understood to be available to operate an all-electric service from Manchester Airport to Glasgow and Edinburgh. This will be achieved by routing them over the Chat Moss route as far as Golborne Junction and then onto the West Coast Main Line. Completion here is due during 2013.

The integration of other projects in the north-west such as the Manchester Hub will also be a key consideration, with plans for linespeed increases over Chat Moss and freight gauge enhancement going hand-in-hand with the electrification. The transfer of TransPennine Express traffic from the current route via Warrington Central is currently being proposed and this is likely to improve the case for eventual electrification of the full trans-Pennine network.

Electrification unit from Oxford
A unit from Oxford crosses onto the GW's main lines at Didcot Junction

New plant and OLE

Network Rail has recently briefed its supply chain on proposals for developing both a new high output installation train as well as two new genres of overhead line equipment. The reason for developing a bespoke electrification train is to enable high rates of installation which hitherto have not been possible with existing plant. Its specification is currently being developed in conjunction with a number of OLE suppliers, with invitations to tender for the design and manufacture likely to be issued shortly. Key to the train’s required performance will be the ability to construct the equivalent of a full-tension length of OLE in a single shift, with the railway being kept partially operational by allowing the passage of trains on adjacent lines. Given the likely procurement timescales, it is thought that the train will first see action on the Great Western route.

Suppliers have also been briefed on the development of two new OLE types. The first design, known as NR Series I, is being developed by Network Rail for application on major routes with linespeeds up to 125mph. Having a required capability to operate at speeds as high as 140mph, the design will be compatible for use with auto-transformer feeding arrangements and be rated for 12kA fault levels, as well as being suitable for installation using the high output train. Network Rail has advised that a system specification is currently being produced which will be issued to suppliers early this year, against which they will be invited to make proposals.

The second type, known as NR Series II, is currently under development by Network Rail and is understood to be the preferred OLE type for application on medium-speed routes such as those in the north-west where linespeeds up to 100mph prevail. It is believed to be a derivative of the current Mk3d design.

The way forward

It would seem that new electrification is still firmly on track with the government committed to the electrification of further routes. Good progress is apparently being made by Network Rail on the Great Western, north-west and Scottish schemes. However the key to ensuring success will be the need to minimise costs and keep the price tag for new wires as low as possible. The benefits gap between electrification and other forms of traction is constantly being eroded as technologies develop so there can be no guarantee of more wiring unless it can be kept at an affordable price.

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