World-first hydrogen narrow-gauge train unveiled for Sardinia

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Switzerland’s Stadler and regional operator ARST have unveiled what reports describe as the world’s first hydrogen-powered train designed specifically for narrow-gauge railways, a prototype destined for Sardinia’s 950-millimetre network and scheduled to carry passengers from 2028.

A prototype built for Sardinia’s narrow-gauge network

The train was presented at Stadler’s commissioning centre in Erlen, Switzerland, on 19 June 2026, following a multi-year development programme triggered by Italian tenders for zero-emission regional rolling stock. Publicly available information shows that the single-deck multiple unit has been purpose-built for Italy’s 950-millimetre lines, making it the first hydrogen train engineered from the outset for such a narrow track gauge.

The new fleet is being procured for ARST, the public transport company that operates most of Sardinia’s secondary railways and tram-train services. According to published technical documentation, the hydrogen multiple unit is intended for regular regional services rather than purely demonstration use, reflecting a shift from pilot projects to fleet-scale deployment in the hydrogen rail sector.

Stadler material indicates that the first Sardinian sets form part of a wider Italian programme covering multiple regions, but the unit unveiled in Switzerland is configured specifically for ARST’s network. The design is tailored to the island’s existing infrastructure, rolling stock gauge and platform heights, allowing hydrogen traction to be introduced without large-scale rebuilding of lines or stations.

Routes, timeline and service role in Sardinia

According to recent coverage from specialist railway outlets, the narrow-gauge hydrogen trains are planned to enter commercial service in Sardinia from 2028, once testing and certification are complete. The units are expected to operate on ARST’s electrified and non-electrified narrow-gauge routes around Sassari and Alghero in the island’s northwest.

Information released with the unveiling indicates that initial deployment will focus on three corridors: Alghero Airport to Mamuntanas, Sassari to Alghero and Sassari to Sorso. These regional and suburban lines currently rely largely on diesel traction, meaning the hydrogen fleet will replace some of the island’s most carbon-intensive passenger services.

The new trains are designed to integrate with Sardinia’s wider mixed-use network, which combines daily commuter services with seasonal tourist operations such as the Trenino Verde heritage trains on more rural stretches. While the hydrogen units are being bought primarily for regular public transport, industry observers note that zero-emission rolling stock could eventually support more sustainable tourism-oriented services on selected sections.

Hydrogen technology and expected emissions cuts

Technical summaries published by Stadler describe the Sardinian multiple units as hydrogen-electric trains, with on-board fuel cells generating electricity from compressed hydrogen stored in roof-mounted tanks. The electric traction system then powers the bogies, supported by batteries that can recover and store braking energy to improve overall efficiency.

Company figures cited in trade press reports suggest that replacing existing diesel stock with ten hydrogen trains on ARST’s network could avoid more than 2,100 tonnes of carbon dioxide emissions per year. The savings arise both from the absence of exhaust emissions at the point of use and from the possibility of sourcing hydrogen from renewable electricity, depending on final production and supply arrangements on the island.

Rail sector analysts highlight that the narrow-gauge design allows hydrogen technology to reach lines where conventional electrification with overhead wires would be technically complex or financially prohibitive. Many of Sardinia’s secondary routes are lightly built and traverse constrained terrain, making a self-powered zero-emission train a potentially more cost-effective path to decarbonisation than full network electrification.

A milestone for narrow-gauge networks in Italy and beyond

The Sardinian order forms part of a broader Italian push to introduce hydrogen traction on regional networks that still depend heavily on diesel. Framework agreements signed in recent years cover additional narrow-gauge hydrogen trains for Calabria in southern mainland Italy, while separate contracts have been announced for similar technology in Sicily. Together, these projects are positioning Italy as a testbed for zero-emission operation on 950-millimetre lines.

Industry commentary notes that narrow-gauge networks, often located in mountainous or rural regions, have historically lagged behind mainline railways in the shift away from fossil fuels. The Sardinian prototype is therefore seen as significant not only for the island but also for similar systems in Europe, Asia, Africa and Latin America, where narrow-gauge lines remain widespread.

By adapting hydrogen fuel-cell technology to the constraints of smaller loading gauges and tighter curves, the new train offers a template that could, in principle, be replicated on other secondary networks. Observers point out that the design also aligns with broader European efforts to promote alternative traction technologies on lines where full electrification has not yet been justified by traffic levels.

Tourism, regional development and future steps

Sardinia’s regional railways play a dual role, carrying daily commuters while also serving as a gateway to the island’s coastal resorts and inland landscapes. Tourism operators have long marketed rail experiences such as the Trenino Verde, which runs on some of the same narrow-gauge alignments now earmarked for hydrogen traction. Travel industry coverage suggests that a quieter, emission-free train could enhance the appeal of rail-based excursions for visitors seeking lower-impact ways to explore the island.

Regional authorities have linked the hydrogen rollout to wider economic and skills-development objectives, seeing the project as an opportunity to build local expertise in advanced rail technology and green energy systems. The procurement programme includes long-term maintenance contracts, which are expected to anchor technical jobs on the island once the fleet enters service.

Before that point, the prototype revealed in Switzerland will undergo extensive testing and homologation under Italian and European safety rules. Railway publications report that trial operations are planned ahead of the 2028 launch date to validate performance on Sardinia’s gradients, curves and climate conditions. If those trials confirm expectations, the island’s narrow-gauge network could become one of Europe’s most visible showcases for hydrogen rail in regular regional service.