The Rail Industry Decarbonisation Taskforce (RIDT) report stated "the government should set out clear, consistent and enabling policies." Siemens, in their submission to the Commons Select Committee, stated that "The biggest challenge to employing alternatively fuelled rolling stock on the rail network is the lack of an overall strategy for the railways." In the absence of this, this site suggests some priorities.
The TDNS aims to "identify preferred combinations of electrification, hydrogen and battery traction options to achieve the most cost-effective low carbon outcome. This should consider not only the preferred long-term solution but also the most effective transitional arrangements.” The latter point is important: simply listing which tracks should be electrified or which routes should be run by battery-powered trains is not sufficient. There needs to be an overall priority list, with a detailed plan of which manufacturers are supplying what when to whom. Such plans rarely go exactly to schedule, so there needs to be flexibility by all parties as well.
- prioritise emission reduction in larger cities/towns first
- as electrifying the trains can be done much faster than electrifying the tracks, with little disruption of current service, this should be started asap
- electrify most-used tracks first:
- those between larger cities/towns (main lines)
- commuter lines into larger cities/towns (many of these are on main lines)
- most-used freight lines
Note that electrifying the track not only improves those lines, but also brings more lines within battery range.
Define larger towns
Although there is some use in Britain of the term 'main line', as in E and W Coast Main Line, it is not consistently applied. This site uses the term to distinguish the long-distance routes with the highest potential usage, and thus those between the most heavily populated towns (freight usage will be more oriented to ports and other major handling centres).
There are many definitions of 'town/city', but this site uses The Geographist's list, taking those with a population over 250,000 to be 'large'. Several other agglomerations like Teesside could be added, and changing the criterion to over 200,000 would add Aberdeen and Penzance. Many other population centres are on the lines linking these towns, and of course many of these lines are already electrified.
It's noticeable that as of 2020 6 of the cities over 250,000 (Bristol, Sheffield, Leicester, Nottingham, Hull, Derby) have no electric trains whatsoever.
Speed of track electrification
As stated in the status page, there are some 16,000km of open rail routes, of which some 38% are electrified. This corresponds to some 31,000 single track kilometres (stk), and the TDNS plan is for 13,000 of those to be electrified.
The Electrification Cost Challenge recommended "two to three delivery teams consistently in action each delivering 75-100 single track kilometres (stk) per annum, for at least 10 years", i.e. up to 300 stk a year. Transport Scotland, in its decarbonisation plan, is aiming for 130 stk p.a; as they say, there may be scope for improving on this as experience is gathered and supply chains improved. For comparison, some 800 route km have been electrified in the last 10 years.
At 300 stk a year, electrifying 13,000 stk would take at least 40 years, so completing this by 2040 seems a tall order, and would require either significantly increasing the speed or doubling the number of teams.
It also should be said that electrification is often part of a larger update to a line, where bottlenecks and other pinch points are removed, signalling/junctions improved, and so on, before electrification is installed. On some lines, this work could well be as great or greater than actual electrification, considerably increasing the time taken.
Scotland has devolved powers, and has in effect had its own electrification team at work for several years. Their plan envisages them continuing outwards from the central Lowlands.
Wales too effectively has its own team working on the Valley Lines, but unlike Scotland has no powers to decide on priorities for the rest of the network. It is also more dependent than Scotland on connections with and via England, so is heavily dependent on priorities there. The Welsh government/assembly would like to take over responsibility within Wales, but this is far from agreed. Within Wales, Cardiff-Swansea and the N Wales line would be a priority, but they are well down the priority list for Britain as a whole.
HS2/Northern Powerhouse Rail/Midlands Connect
As the main line from London to Birmingham and Crewe is already electrified, the first phase of HS2, due around 2030, won't much affect electrification. If it is competitively priced, it will probably reduce long-distance traffic on the remaining unelectrified line out of London, the Chiltern line from Marylebone to Birmingham.
Phase 2 will have a greater effect, but is currently pending the Integrated Rail Plan and it's not clear when it might be complete. The Sheffield branch of phase 2 as currently planned requires electrification from the junction with the Midland Main Line (MML) near Clay Cross to the junction north of Thurnscoe. Midlands Connect's plan for classic-compatible trains between Bedford and Leeds also requires electrification of MML from its current northernmost point to Toton; Nottingham-Birmingham similarly requires an electrified loop from Nottingham to Toton. These constitute the majority of MML, so it makes sense for electrification of this to be reinstated.
Phase 2b also requires the short stretch between Church Fenton and York to be electrified, something which is already underway.
NPR's latest plans propose new high-speed lines Liverpool-Manchester-Bradford-Leeds, separate from the Trans-Pennine Upgrade, currently underway. They also specify electrification of Leeds-Hull and Sheffield-Hull. Electrification of Manchester-Sheffield is not specifically mentioned, but implied if journey times are to be improved.
The current map makes clear that there are large numbers of lines which are currently in battery range, and quite a few more which could be within range if there's recharging at the terminus. So the priorities here seem to be:
- aim to reduce/eliminate emissions in the most populated areas first
- replace diesel with electro-battery trains for those routes which run between electrified lines or are branch lines within range
- prioritise partial electrification at termini and other strategic points to maximise the usage of battery trains. It may also be possible to redesign routes to optimise recharging.
- have flexible arrangements/contracts with manufacturers so that:
- batteries can be replaced as and when better versions are available
- diesel bi-modes can be replaced with batteries and/or hydrogen as quickly as possible
- batteries can be removed as and when tracks are electrified
It's hard to be too sure what battery ranges will be in 5 or 10 years time, but current electric cars can manage 300-500km or more, something which is expected to improve in the coming years, especially if solid-state ones make it to mass production. Manufacturers are planning electric HGVs with 500km range by mid-decade. It's surely not unreasonable to expect train batteries to manage 250km by 2025, and 500km by 2030. This means that all routes in Britain would be reachable with battery power, especially with intelligent use of station recharging. Shorter routes can use a smaller battery, thereby reducing the weight. The maps use these assumptions.
In England, there are effectively 2 teams currently at work, on MML and on the Trans-Pennine Upgrade, i.e. the Midlands and the North.
As most of the MML through to HS2 in Yorkshire will have to be electrified anyway, it makes sense for the team currently working on the line to simply continue N, and bring electric trains to 4 of the large cities currently without them. Mkt Harborough-Derby-Sheffield plus branch to Nottingham and loop via Rotherham is some 150 route km, Trent Jcn through Toton to Clays Cross some 40 route km, and Sheffield N to the E Coast Main Line at S Kirby Jcn some 30 route km. While they're at it, they could also electrify Mexborough-Doncaster (part of NPR, 15 route km), and also the Nottingham-Toton loop (needed for HS2 link, 10 route km). Say a total of 500 stk; it should be possible to complete most of this by 2025 (the original plan to electrify Kettering to Sheffield and Nottingham was to take 4 years).
The Transpennine Upgrade Manchester-Leeds-York is not yet fully specified, but electrification of the York-Church Fenton and Huddersfield-Leeds sections is already planned/underway. The total route km is around 100, so this should also be complete by 2025, and there may be scope for making a start on some of the neighbouring lines (see below).
In Scotland, the priorities are for the remaining central lowlands routes to be electrified, to E Kilbride and Kilmarnock, the Maryhill line, and Borders, plus the reopening Levenmouth line (which would put battery trains in range of Edinburgh). This represents some 200 stk, leaving time for further developments in Fife before 2025.
In Wales, S Wales Metro is scheduled for completion by 2023, leaving time for the team to move on to other lines by 2025. Cardiff-Swansea is around 80 route km, though there is also a plan to create a new, more direct route east of Swansea, and it would make sense to do this at the same time.
To complete the NPR route upgrades in time for HS2 phase 1, the Leeds team would complete:
- Leeds-Hull 80 route km, including the spur S from Selby to ECML, and bringing electric trains to a fifth large city. It would probably make sense to include the loop to Hull docks.
- Manchester-Sheffield 60 route km
A new Manchester-Bradford-Leeds line is unlikely to be ready for many years yet, so it would make sense to also electrify the existing Manchester-Bradford-Leeds line (60 route km).
Say 400 stk or 4 team years.
The MML team could move back to the Midlands, and complete:
- Birmingham-Leicester 60 route km
- Coventry-Nuneaton 20 route km
- Birmingham-Derby 50 route km (which may go down in priority if HS2 to Toton is prioritised)
- Derby-Stoke 50 route km
Say, 400 stk in total.
Within Wales, the next priority would probably be the N Wales line, but for Britain as a whole, it would make more sense to prioritise connecting routes from S Wales to Birmingham and Bristol.
- Birmingham-Bristol 100 route km
- Cheltenham-Cardiff 60 route km
- the remaining 50 route km from Great Western electrification in Bristol, thereby bringing electric trains to the final large city (much of the preparatory work has already been done)
This is also around 400 stk.
In Scotland, the total route km in Fife, plus Stirling-Dundee, is some 230, say 500 stk.
The outstanding 'main line' would be Bradford-Carlisle, some 140 route km.
South and Midlands
The remaining main lines with approximate route km to be electrified would then be (from the south):
- Southampton-Bristol 85 route km (stretch near Southampton needs dual supply)
- Basingstoke-Reading 25 route km (needs either Southampton-Basingstoke to be dual supply, or trains with ability to use both)
- Didcot-Coventry 100 route km
say 400 stk in total.
In Scotland, Dundee-Aberdeen is some 120 route km, and Kilmarnock-Carlisle some 140.
The Welsh team could move to N Wales (some 140 route km, plus 60 for connections to Crewe and Warrington), but due to the lack of clear priority this is not shown on the map.
At the moment, those lines outside battery range, for example, in N Scotland, most of Wales, SW England, will have to use trains with a hydrogen tank. But even here, it may be possible to reduce the size needed by a program of partial electrification, along with use of hydrogen-electric bi-modes. And if batteries develop as anticipated, by 2030 hydrogen may well no longer be needed.
Other proposed new/reopened lines
Proposals for new/reopened lines should commit to a decarbonised option; as the TDNS says, it makes no sense for them to plan on using diesel.