Scotland’s rail fleet strategy: more than just trains

This article looks at why fleet strategy matters and what it could mean for Scotland’s rail future. Scotland’s Railway is a combined effort between ScotRail and Caledonian Sleeper (under Scottish Rail Holdings) and Network Rail, as organisations receiving strategy, specification, and funding from Transport Scotland, the transport agency of the Scottish Government, together with trains from English Train Operating Companies (Avanti, CrossCountry, LNER, and Lumo), the freight sector in Scotland, and the Scottish rail industry supply base. For some years, the Scottish Government has recognised that ScotRail and Network Rail are funded separately but from the same pot, so the overall profit and loss account only comes together on the civil servant’s desk in Transport Scotland. Therefore, Transport Scotland has encouraged collaborative working between ScotRail and Network Rail and specifies its aligned and integrated requirements to the former through a Grant Agreement and Scotland’s own High level Output Specification to the latter. There has been consistency of strategy, and teamwork between organisations is encouraged and valued. It is reported as being as easy as A-B-C: - Alignment of objectives between operator and infrastructure manager with the strategic objective of the Scottish Government - Building the capability of the staff and the railway, and being - Competitive – attractive services delivered efficiently recognising that customers have alternatives. All of this has delivered efficiency including, for example, electrification around 30% cheaper per single track kilometre than in England, and signalling delivered more efficiently too. Scotland’s railway has some big opportunities ahead. With much of ScotRail’s fleet ageing, passenger habits changing and pressure growing to decarbonise transport, the decisions made now will shape the network for decades to come. Why this moment matters Fleet strategy is about far more than buying trains. For example, new rolling stock only works well when the rest of the system is ready for it; electrification must be in place where it is needed; and depots need the right capability, capacity, and equipment. In addition, stations and platforms may need to change and digital systems such as passenger information, reservations, and onboard connectivity must support the service being promised. Above all, the different parts of the railway and government have to move in step. In Scotland, that means close alignment between ScotRail, Network Rail, suppliers, and Transport Scotland. This whole-system view is especially important because much of ScotRail’s current fleet is both old and unusually varied. That creates extra complexity in maintenance, training, depot operations, and spares. It can also produce an inconsistent passenger experience, with travellers finding that comfort, luggage space, accessibility, and layouts vary depending on which train turns up. Many trains have already had their life extended and are suffering corrosion, wiring deterioration, and parts becoming harder to source. Around 65% of ScotRail’s fleet is old enough to need replacement over the next few years, providing the opportunity to redesign the fleet in a more coherent way rather than replacing one class at a time. Such an approach will link to the aims of Scotland’s wider transport strategy which places emphasis on equality, climate action, economic growth, and health and wellbeing. Better accessibility supports equality, cleaner traction, and a shift away from car travel supports climate and health goals. Better links between communities and tourist destinations support economic growth. Changing demand and a changing population The strategy also will reflect the way travel has changed without preventing future further changes if habits change again. Since 2020, weekend travel has become stronger, leisure now plays a bigger role, and traditional commuting is weaker on Mondays and Fridays than it once was. In 2025, ScotRail’s busiest days coincided with major sports events, concerts, the Edinburgh Festivals, and the weekend before Christmas. Also, Scotland is forecasting a demographic shift towards an older population. That has several implications. More passengers will need step-free and level access, clear information, and spaces that work better for luggage, buggies, and wheelchairs. A smaller working-age population may also make it harder to attract maintenance and operations staff in the long term. In other words, the trains of the future must be easier both to use and to maintain. Electrification at the centre In the long run, electric traction is the best answer for most of the network. Electric trains are cleaner at the point of use, generally cheaper to run, and usually more reliable and higher performing than diesel alternatives. Scotland’s strength in renewable electricity gives this argument extra force. Scotland has already demonstrated the benefits of a rolling programme of electrification compared with the stop-start approach seen elsewhere in Britain. A steady programme of electrification will build skills, control costs, and avoid the waste that comes from repeatedly ramping work up and down. Battery trains will probably play an important transitional role, especially on partly electrified routes, but will not be the final answer everywhere. Although freight traction is outside the scope of this strategy, it does consider that electrification of the network remains the preferred end-state for the main Inter-City and Suburban passenger services where there is also freight traffic. Hence, in respect of electrification, it recognises the synergy between freight and passenger traffic. Diesel trains will not disappear overnight. The diesel services are the Inter-City and rural/scenic routes as well as parts of Fife and the Borders line. This affects the order in which fleet replacement should happen. Scotland cannot replace everything at once, and nor can the wider rail supply chain deliver multiple large fleets simultaneously without risk. Sequencing is therefore crucial: the right train must arrive at the right time, on routes where the infrastructure can support it, and with depots prepared to look after it. It is also helpful to have a stable workload, rather than peaks and troughs, which can also help to minimise disruption while infrastructure is upgraded to support new trains. Fewer fleets, better planning One of the goals is to consolidate from today’s 11 fleets to roughly five main groups. The broad idea is to retain the existing modern classes 380 and 385 electric fleets, introduce a new suburban electric and battery-electric family, provide an Inter-City transition fleet in the short to medium term, plan for a future intercity electric fleet, and tackle the rural fleet later as infrastructure choices become clearer. Fewer train types will reduce maintenance complexity, simplify training, improve resilience, and make the passenger offer more consistent. Rail procurement is a slow process. A full cycle from early business case to fleet introduction can easily stretch over a decade. Strategic work, market engagement, formal procurement, train building, testing, and fleet rollout all take time. That is why it is important to start planning around 10 years before the trains are actually required. If planners and decision-makers wait until a fleet is already showing the effects of ageing, they are almost certainly too late. The economics of replacement can be difficult to explain politically because old trains and new trains can be expensive in different ways. Older fleets may look cheaper because their lease costs are lower, but their maintenance bills rise over time, sometimes unexpectedly, and obsolescence becomes a serious (i.e., expensive) problem. Failures become more frequent, parts are harder to find, corrosion becomes an issue, and keeping the trains in service takes more effort. New trains often have the opposite profile: they may cost more to lease, but they can be cheaper to run and maintain. The challenge is that the point where those estimate lines cross may be years away, while funding decisions must be made now. There are also practical limits on how fast change can happen. Depots are already busy, stabling space is finite, and the industry cannot absorb several major fleet introductions at the same time without creating new risks. That is why Scotland’s programme has to be phased. Some parts are already more advanced, including the Inter-City transition using five-car Class 222 trains, the procurement of a new suburban fleet, and electrification work for Fife and the Borders. Other elements, such as long-term rural fleet replacement and a future fully electric Inter-City, remain more strategic and will depend on later decisions. Inter-City Inter-City services are particularly important. Although they make up a relatively small proportion of ScotRail’s overall timetable/mileage, they generate a significant share of revenue and are central to Scotland’s appeal for both business and tourism. That helps explain the urgency of replacing the much loved but life expired HSTs. At around 50 years of age, they are increasingly expensive to maintain, availability is poor, and it no longer offers the consistent experience expected on a modern Inter-City route. The immediate answer is 22, five-car Class 222 trains cascaded from East Midlands Railway (EMR). They are being leased from Beacon, will receive heavy maintenance and extensive refurbishment by Alstom and are expected to be in service from 2027. They will include the following features: - External repaint in ScotRail livery. - Interior refresh, including new carpets and full interior repaint. - A new passenger information system with multimedia displays. - WiFi with Low Earth Orbit Satellite connectivity and voice-over-internet phone capability. - A new electronic seat reservation system. - A new CCTV system for the safety and security of customers and staff. - An intelligent engine start-stop (automatically stops an engine to reduce emissions). - New First and Standard Class seats and tables, with 240 V plug sockets, and both USB-A and USB-C sockets at every seat. In addition, they will offer a family friendly area, providing space for passengers with an unfolded pushchair; one wheelchair space in First Class and two spaces in Standard Class; storage for six bikes; onboard catering facilities to support at seat and trolley service; and seat layouts arranged to maximise window alignment and luggage storage. While diesel powered, these trains are expected to be more fuel efficient than HSTs leading to lower emissions. These trains are leased until 2036, with the possibility to extend until the early 2040s, when it is expected that enough electrification will have been completed to enable Inter City BEMUs. The routes to Aberdeen and Inverness will need to be partially electrified by 2040 for battery-electric to work. Suburban The priority for new trains is the suburban fleet where most of the fleet is approaching 40 years old or has already exceeded that. The new suburban fleet is likely to have the widest day-to-day impact because these services carry the largest share of ScotRail passengers. The procurement process has started to select builders and funders. The official notices talk of a minimum of 69 trains, with a potential option for additional orders of up to approximately 37 trains. It is intended to procure a standardised fleet of BEMUs to replace suburban Class 156 diesel units and EMUs to replace classes 318, 320, and an option to replace Class 334. The latter is only 25 years old but would be 30-35 years old by the time of replacement. The trains will be required to have improved on-board facilities including air-conditioning, greater reliability, and increased accessibility including level access boarding and alighting (in a way that minimises the need for platform adjustments). Also required are active travel provision such as improved spaces for bicycles and wheelchairs, and inclusion of family friendly areas (where families can sit with a baby in an unfolded buggy), leading to more comfortable journeys. Compared with diesel or conventional electric trains there are system challenges to be overcome when deploying BEMUs, requiring an iterative design process that considers at least the following: - Timetable/stock diagrams – to create opportunities to charge batteries. - Topography (stations stops, gradients etc.), train speeds and battery size affecting self-powered range. - Power supply capacity – recognising it needs to have the capability to supply the whole operation through the electrified sections. - Extent of electrification – to ensure sufficient charged batteries – linked to battery capacity. - Stabling/charging (linked to power supply for depots/stabling points) – existing electrified depots/siding might need higher capacity to allow for battery charging. - Contingency in case of disruption – e.g., line blockage just short of a charging section/location. This iterative process should be supported/informed by modelling as was seen in the development of the discontinuous electrification system for the Cardiff Valley lines. In order to enable BEMU operation intermittent electrification will be provided on the Fife and Borders lines. The existing diesel trains on these lines will be transferred to mid-life diesel trains from F&B to rural routes, improving the passenger experience on the West Highland and Southwest Scotland routes. Rural scenic routes Rural routes are more difficult because they serve a wider mix of purposes and often depend on infrastructure choices that have not yet been made. These lines support tourism, connect communities, and link into ferry travel, so their social and economic value goes well beyond simple passenger counts. In the shorter term, electrification elsewhere will cascade some diesel multiple units – mainly Class 158s and Class 170s – to improve these routes whilst longer term, more permanent solutions are developed. These routes need clear long-term decisions about traction and infrastructure. A railway in transition Scotland is not simply replacing old trains with new ones. It is deciding what kind of network it wants in the future. That includes how simple or complex the fleet should be, how quickly electrification should spread, how accessible services must become, and how investment can be timed to deliver long-term value rather than short-term fixes. None of this will be easy, but there is a very clear positive message. Because so much of the fleet now needs attention at the same time, Scotland has a genuine once-in-a-generation chance to reshape its railway into something cleaner, simpler, more reliable, and more useful for the people who depend on it. This article is based on talks given by Bill Reeve and Louise Shaw from Transport Scotland and by Jon Newton from Scottish Rail Holdings to the IMechE in May 2026. Image credit: iStockphoto.com/WCJohnston