The innovative trains operate on batteries, electric lines, or diesel, providing a transition in decarbonizing rail systems.
The U.K.’s quest for a zero-emissions rail system has a problem: A considerable portion of the train network still runs on diesel. Fully electrifying the routes would take years and cost a fortune. This is valuable time the industry doesn’t have. So, what’s the fix?
Hitachi Rail and Turntide Technologies have teamed up to build the U.K.’s first fleet of battery-powered intercity trains. These new “tri-mode” trains can run on electric lines, batteries, or even diesel if needed, making them flexible enough to handle just about any route. The rail system could significantly reduce emissions without waiting on full electrification by switching to battery power where overhead lines aren’t available.
Concept of the tri-mode train will look. Image used courtesy of Hitachi
The Tri-Mode Train
Hitachi Rail’s next generation tri-mode platform brings together three power sources: electric, diesel, and a newly integrated 700 kW LFP battery into a single, highly flexible propulsion system. These trains are designed for adaptive energy management. Their onboard control systems continuously evaluate route conditions and station proximity to determine the most efficient use of each power source. The system also prioritizes battery discharge when operating in eco-mode, which enables a significant reduction in diesel fuel usage. Regenerative braking further boosts efficiency by recovering during deceleration, returning energy to the battery for reuse.
Real-time diagnostics embedded throughout the traction and battery subsystems enhance maintenance. These onboard systems track battery health, thermal stress, discharge rates, and cycle count to support predictive maintenance scheduling. The data allows communication with the operator on service health, giving notification of anomalies before they impact processes.
Turntide has already placed nearly £10 million in orders, leading to an expansion of its Gateshead facility. The total order is worth around £300 million and includes 45 railcars, part of a new Grand Central fleet operated by Arriva and financed by Angel Trains. Officials see this innovation as a turning point that could transform the North East into a national hub for battery train technology.
Gen 2 LFP Battery Details
The Gen 2 lithium-iron-phosphate (LFP) batteries are smaller, lighter, and more powerful than older traditional lithium-ion systems. They deliver better energy density without compromising safety or longevity. LFP chemistry provides thermal stability and extended lifecycle, making it ideal for demanding rail applications.
Installing a battery in a train. Image used courtesy of Turntide Technologies
However, the engineering precision behind the battery’s form factor is the real innovation. The batteries are designed to match the traditional diesel engine’s dimensions and mounted directly in the undercarriage without any structural redesign. This preserves axle load, track integrity, and compatibility with existing depots and maintenance facilities.
Each battery system is paired with Turntide’s advanced battery management software, built to meet safety integrity level 2 (SIL2) standards under IEC 61508. The batteries can detect and mitigate hazards in real time, even in a partial system failure. They also comply with IEC 62243 cybersecurity standards, ensuring resilient protection against digital threats.
Turntide’s battery units were trialed on U.K. rail lines in 2024. The trains powered themselves in and out of stations with zero emissions, reached speeds over 75 mph, and reduced fuel consumption by up to 50% on hybrid runs.
The Rails Are Cleaner Around the Corner
Challenges in decarbonizing U.K. rail aren’t going away. Still, the solution is closer with battery-electric trains rolling out from the same region that gave birth to the railway 200 years ago. Clean, quiet, and locally made, these trains are set to reshape rail travel from the ground up.
