A NEW report from Network Rail is setting out plans for the future railway, and it reveals that the last diesel trains could be withdrawn or converted to other forms of traction within three decades or less.

The report, an ‘interim business case’, sets out the strategy for decarbonising the network. One key recommendation is that ‘from now on, diesel-only trains should only be bought where there are clear strategic and economic reasons for doing so. Where this is necessary, only trains where the possibility exists in future to replace the diesel engines with a zerocarbon alternative should be chosen’.

Future traction sources are more conventional electrification, batteries or hydrogen fuel cells, and the report makes it plain that there is no ‘one size fits all’ solution.

It says electrification will continue to be best for lines carrying long-distance high-speed trains and freight services, because neither hydrogen nor battery trains have enough power.

At the moment, there are 15,400 single track kilometres on Network Rail’s infrastructure which have not been electrified, and few of these are in the south east of England. On the other hand, there are no electrified lines west of Bristol or significantly north of the Scottish central belt, and very few in Wales and East Anglia.

The alternatives to diesel traction vary according to the type of traffic each line carries. 

Some local lines in Cornwall and parts of the north of England are being nominated for battery trains , amounting to 400 STKs (single track kilometres) in total, but a substantial extension of 25kV electrification will connect with these, amounting to 11,700 STKs.

These lines include the Midland Main Line and its connecting routes, including those to and beyond Lincoln, as well as East West Rail, the completion of both Great Western routes from Reading to Exeter and onwards from there to Paignton and Penzance as ‘ancillary electrification’. Salisbury to Exeter also comes within this category, while electrification combined with other modes is proposed for the lines to Barnstaple, Exmouth and Newquay.

In the West Midlands, electrification would be extended from Bromsgrove to Worcester and Bristol, from Wolverhampton to Shrewsbury, on both lines to Stratford-upon-Avon, from Leamington Spa to Didcot via Oxford and also from Leamington to Nuneaton via Coventry, and on the lines east of Birmingham to Leicester and Derby. Also towards Oxford, the North Cotswolds line from Worcester would be electrified.

In Wales, hydrogen trains seem likely on the Cambrian routes and the Heart of Wales line, again perhaps combined with other forms of traction, but there would be full electrification through to Holyhead in the north and Carmarthen in the south, with ‘ancillary electrification’ onwards from Carmarthen to Fishguard. In the Welsh borders most routes to Shrewsbury would be electrified, except for the hydrogen lines running west or south west into Wales.

In East Anglia, electrification would be extended east from Peterborough and Cambridge to Norwich, with hydrogen preferred beyond Norwich to Sheringham, Great Yarmouth, Lowestoft and on the East Suffolk line from Lowestoft to Ipswich. The branch to Felixstowe, which has heavy freight traffic, would be electrified.

There would be a major electrification programme in the north of England, including the lines to Hull and Scarborough as well as the dense network of local routes in South and West Yorkshire and also around Greater Manchester. Battery trains will also be used on a few lines, including York and Harrogate, Beverley and Scarborough, and on the secondary line to Blackpool South.

Both the Cumbrian Coast and Settle & Carlisle lines are earmarked for ‘ancillary electrification’, while the Glasgow & South Western line from Carlisle through Dumfries to Glasgow would be electrified. North of the Scottish central belt, both routes from Perth to Inverness would be electrified, while hydrogen would be used in the western Highlands on the lines to Mallaig, Oban and Kyle of Lochalsh and also on the Far North line to Thurso and Wick.

The plans are ambitious, and even outstrip the lavish proposals for virtually network-wide electrification which were promoted, unsuccessfully, by British Rail in 1981.

This report, however, makes its priorities clear, saying: ‘Ultimately, diesel cannot play any part in a zero-carbon railway.’

There are still many uncertainties. As things stand, 11,700 single track kilometres are candidates for electrication, while 400 STKs will be used by battery trains and 900 more by hydrogen units. The way that the remaining 2,300 STKs will be operated is not yet decided, because at the moment there is ‘no clear technical choice’.

In his introduction, Network Rail system operator managing director Paul McMahon says: ‘Climate change is a real and growing threat. Every year, across the planet, weather records are broken, and we see more frequent extreme weather, from flooding to drought. It is becoming increasingly urgent for countries and businesses across the world, to protect the planet for future generations. In June 2019 the UK Government set out a legislative target to achieve ‘net zero’ greenhouse gas emissions by 2050. For rail specifically the Department for Transport asked the rail industry to explore whether it would be possible to remove all diesel-only trains from the network by 2040 in England and Wales. The Scottish Government also set a target to decarbonise domestic services by 2035.

‘Over the last year Network Rail has worked collaboratively with the rail industry to establish how we can best work together to achieve this. The result of this work is the Traction Decarbonisation Network Strategy and I am delighted that we are now able to set out the different ways how we could minimise direct carbon emissions from trains.

‘Carrying out this work in a way that is efficient and represents best possible value for money is essential. This strategy shows that the best way of doing this includes a long-term, stable and efficient programme of electrification which will last for at least thirty years, alongside the introduction of new technology. If we can do this, I am confident that rail will play a vital role in helping build Britain back better and achieve the Government’s commitment to achieve net zero by 2050.’