Delve into the Scottish Government’s updated climate change plan and there’s a picture of an electrified railway on the title page of the chapter about transport.

Look past the profusion of bushes growing from the viaduct and there’s a diesel Voyager. Thus in one picture is a summary of rail. It wants to be electric but is too often diesel and it’s a network in need of repair.

The plan contains a bold pledge to “almost completely decarbonise our passengers railways” by 2032 while “car kilometres will have reduced by 20%”. That commits the Scottish Government to reduce rail’s already very low proportion (1.2% in 2017) of transport’s carbon emissions while recognising that shifting people from car to rail (or other low carbon transport such as walking, cycling or buses) is important in cutting overall emissions.

Electrification momentum fell away

Momentum fell away from Scotland’s rail electrification project after it converted the main Edinburgh-Glasgow route in 2018, together with routes via Shotts and Falkirk Grahamstown, and the line northwards through Stirling to Dunblane and Alloa. Wiring is to restart with the branch line to East Kilbride and the line to Barrhead. There’s also development work to wire the Borders line to Tweedbank and the line to Levenmouth that Network Rail is currently rebuilding from dereliction. To bring electric-only trains to Levenmouth will likely need parts of Fife’s network electrified. Extending wires through Fife towards Dundee sets Transport Scotland up to continue onwards to Aberdeen.

The Scottish Government is committing £550 million towards rail decarbonisation according to its latest infrastructure investment plan, published in February. It’s part of a wider £1.23 billion improvement programme that includes £200m for improvements between the Central Belt and Aberdeen which is likely to result in new signalling (much of the route north of Dundee is signalled under absolute block regulations by a string of mechanical boxes), line speed improvements and changes to loops.

Transport Scotland is keen to expand its electric rail network to encourage more people to switch from cars and to provide an alternative to lorries for freight. ScotRail 385115 stands at Alloa on December 10 2018 with one of the station’s very first electric services. Behind the unit, a freight line continues towards Dunfermline and might provide a route for electric trains to Levenmouth. PHILIP HAIGH.

Complex documents

There’s been a slew of documents about Scottish transport planning over recent weeks. They’ve unleashed a forest of acronyms – NTS2, NPF4, STPR2 to name a few – which makes deciphering Scottish Government plans difficult. Even STPR2 (the second edition of the Strategic Transport Projects Review) admits this. It says: “The policy, plan and investment landscape that we are presented with is complex and multi-layered.”

But it provides a clear view: “There is an overarching and urgent imperative to address climate change and to achieve net zero carbon by 2045.”

December’s National Transport Strategy Delivery Plan adds a little more clarity. It explains that STPR2 has two stages. The first outlines a short-term program for delivery in the next three years. The Scottish Government published this in February 2021. The second stage should come later in 2021 to set out a transport investment plan for the next 20 years.

Concentrate on the cities

The rail options in this first phase concentrate on developing major stations. Edinburgh Waverley’s masterplan moves forward. Transport Scotland will review capacity at Glasgow Central to find short-term ways of allowing longer and perhaps more frequent trains. A masterplan beckons too for Inverness in line with long-standing local wishes. The fourth major station is Perth. Here the station’s dingy roof detracts from its overall design. It has a track layout and signalling from a different era. STRP2 says: “Track and signalling infrastructure enhancements on the approaches to the station will support faster journey times and better service performance.” Remodelling is also a vital precursor to electrification.

Transport Scotland’s station improvements follows the radical rebuilding of Glasgow Queen Street over the past few years. Meanwhile, STPR2 also notes imminent improvements for Aberdeen, Motherwell and Stirling.

Stepping away from heavy rail, the document reveals ambitions to build ‘Glasgow Metro’. It explains that this is an ‘umbrella term’ to describe a new public transport system that serves Glasgow and its surrounding areas of East Dunbartonshire, East Renfrewshire, North Lanarkshire, Renfrewshire, South Lanarkshire and West Dunbartonshire.

This system might be light rail (RAIL 879), tram or bus rapid transport. TS explains that it will complement and be integrated with existing bus and heavy rail networks. “It may include completely new alignments, reuse of disused former railway alignments and/or the conversion of existing rail alignments to a new mode,” it says.

It’s too early to say precisely which corridors it will use. TS notes a potential focus on underserved areas with poor connectivity, a need to improve access to the city centre, hospitals, colleges, employment centres, shopping centres and leisure facilities.

There are equivalent words for Edinburgh which already has a tram line from its centre to its airport and is building a second line to Leith. City councillors heard in February that the strongest options to extend the tram network were a line north to Granton and one heading south-west towards the city’s Bio-Quarter and the Edinburgh Royal Infirmary.

Decarbonise transport

Decarbonisation forms the third major rail aspect of STPR2 and for rail it follows last summer’s overall plan. Transport Scotland has ambitions to electrify the main lines north from the Central Belt to Aberdeen and Inverness. TS Rail Director Bill Reeve told RAIL that this was likely to use a mix of wired and unwired sections in the interim with gaps bridged by using battery electric multiple units (BEMUs).

He explained that the Borders line would need a new electrical feeding point at its southern end because there is insufficient power for the whole line from existing feeders at the northern end. Wiring might advance from both ends with any gap bridge by BEMUs. Eventually the whole route would be wired and could switch to straight EMUs. He added that capacity improvements would come from longer and better performing EMUs rather than by adding sections of double track. (It’s worth noting that a southern feeder would help when it comes to any extension toward Hawick or even beyond.)

Batteries to Levenmouth

BEMUs also feature in Levenmouth wiring. Reeve told RAIL that the Forth Bridge would need a careful electrification design to befit its World Heritage Site status. He said that BEMUs could bridge the electrification gap in the meantime. TS will need to decide between options. One pushes wiring east from Alloa via Dunfermline and Glenrothes with Thornton to reach the Levenmouth branch. The other concentrates on the route from Edinburgh via the Forth Bridge. Both point towards Dundee (with the challenge of wiring the Tay Bridge) which fit with its ambition to reach Aberdeen.

The current gap between Alloa and Thornton North Junction (where the line to Levenmouth diverges) is around 18 miles. The current gap from Edinburgh is nearer 30 miles. 

Both sit within the likely range of a future BEMU if it recharges from Levenmouth’s overhead lines.

Reeve expects BEMUs to cost around one-third more than an ordinary EMU and this is another factor TS will need to weigh as its develops its electrification plans.

Reeve added that while a BEMU could bridge gaps, the same was not true for freight trains. They rely on diesel or electric haulage. The alternatives mooted for passenger services (batteries or hydrogen fuel cells) are not suitable for freight. Freight needs electrification.

Encourage railfreight

He’s keen to see more electric freight in Scotland and more freight switched from roads. This brings overall benefits in terms of carbon emissions. It means that BEMUs are simply a stop-gap because Scotland’s overall ambition remains an electric railway wherever justified. STPR2 recommends work to improve freight loading gauge between Glasgow and Carlisle via Dumfries, and the Annbank line. It recommends work to improve flows on the West Coast Main Line, and central Scotland to Aberdeen, Inverness and Fife.

Meanwhile, Network Rail has just received planning permission for a new station at Reston. It’s submitted a planning application for Inverness Airport station and it’s about to do the same for East Linton.

A version of this article first appeared in RAIL 925 in February 2021.

By Philip Haigh

Freelance railway writer, former deputy editor at RAIL magazine - news, views and analysis of today's railway.