At the Siemens Test and Validation Center in Wildenrath, Germany, a CAF Class 557 train completed a 273-kilometer journey on onboard batteries alone, without diesel or overhead wires. The test comes as Europe looks for ways to cut diesel use on regional rail lines.
The train was a production-series Class 557 fitted with LTO batteries. CAF engineers ran it through a full circuit without external power, collecting data on energy use and traction alongside battery performance under controlled but demanding conditions. CAF and industry reports describe it as a production train, not a prototype. The results will help shape future battery train projects.
The Class 557 is based on CAF’s Civity platform and intended for the Verkehrsverbund Rhein-Ruhr (VRR) regional network. CAF plans to exhibit the model at InnoTrans 2026 in Berlin, scheduled for September 22-25, 2026, as it seeks to persuade operators that battery trains are practical on lines without electrification. Test data will inform energy management for future deployments.
The 273-kilometer figure needs context: CAF says it does not guarantee the same range in daily service. The test ran on a controlled track, and the company has not disclosed details such as average speed or starting charge, nor the battery level at the end. In regular operation, hills and stops can cut range, as can passenger numbers and the energy used for heating or cooling. Operators must also account for delays or detours, along with weather. Industry reviews say the VRR’s longest required battery-only segment is about 220 kilometers, putting CAF’s result well above that mark. The project has faced delays, but, and passenger service is now expected later than initially planned.
Battery trains such as the Class 557 are intended for routes where full electrification is too expensive or complicated. They charge from overhead wires where available, then switch to battery mode on unelectrified stretches. This allows zero local emissions on lines that would otherwise use diesel, but creates challenges for charging infrastructure and scheduling.
Battery trains differ from hydrogen trains, which generate electricity onboard using fuel cells. Each technology brings different demands for infrastructure and maintenance, with costs varying too. Route length and service frequency shape the choice between battery and hydrogen, as does the ease of recharging or refueling. European rail operators and regulators are weighing these questions as they assess their options.
CAF’s test is one of several recent technical milestones as the rail sector moves to phase out diesel. The data will help validate simulation models and guide future designs, but the Wildenrath result does not cover every route or operating condition. Industry observers say the basic question is how test results translate to real-world operations, particularly in winter or on more demanding routes. As in the EU’s ongoing debates over electronic speed limits for motorcycles, reported earlier, daily operating conditions matter more than headline figures.
CAF has shown that a production train can cover a impressive distance on batteries alone. The more demanding test begins when these trains enter regular service and face the unpredictable realities of regional rail. Further operational data will show whether battery trains can meet daily demands or whether their limits will require new solutions as Europe seeks to cut rail emissions.
