Rail E-ssentials

Where the new generation of trains is concerned, the expression 'running at full steam' refers to more than the advent of pioneering technology. It also applies in chemical terms, because these new-generation trains literally produce nothing but “steam” – making them a zero carbon-emission trains in the rail sector. As a certification and inspection body, TÜV SÜD Rail is involved in Alstom's Coradia iLint project, the development and approval of a hydrogen-fuelled multi-unit train set.

Taking the widespread multi-unit diesel trains of the Coradia Lint 54 type as a basis, Alstom is currently developing the Coradia iLint train, a hydrogen-fuelled multi-unit train set which will soon be put into commercial use. In this drive concept, the chemical energy bound in hydrogen is converted into electrical energy using a fuel cell. Lithium-ion batteries serve as energy storage systems (ESS). They can also store braking energy and generally serve as buffers between the fuel cells and the drive unit. The hydrogen storage systems are accommodated in tank systems on the roof of the train. Two fuel-cell systems thereby are produced in Canada.

The hydrogen drive system of the Coradia iLint provides starting tractive effort and power that are comparable to the diesel trains already in use. Depending on the requirements profile, when fully fuelled the train has a range of over 1000 kilometres and can easily reach a maximum speed of 140 km/h.

TÜV SÜD Rail GmbH has been involved in Alstom's Coradia iLint programme for over 3.5 years and has been responsible for the testing and commissioning of the first two prototypes. As the manufacturer, Alstom is responsible for the design, development and building of the vehicles, while TÜV SÜD is involved in defining requirements and in the safety-related testing of the design as well as its features.

As safety testing spans several systems, TÜV SÜD has been entrusted with a variety of tasks. Testing refers to various disciplines, including the energy-generation system, on-board hydrogen storage and the necessary hydrogen refuelling infrastructure and safety systems at the train servicing and maintenance stations. Thereby, TÜV SÜD Rail has the role of lead project manager, coordinating all tasks related to the approval of the rail system within the TÜV SÜD Group.

The project is making satisfactory progress, with positive milestones being achieved. Inspection and certification of all sub-systems is now almost completed. Full approval based on an EU-wide valid TSI certificate from the Federal Railway Authority (Eisenbahnbundesamt, EBB), the German approval authority, is expected in 2018. 

The services provided so far cover certification of sub-systems, including the hydrogen tank system and the fuel-cell system, as well as general safety assessment of the interaction of all hydrogen sub-systems. One focal area of safety assessment concerns the possible impacts on the hydrogen system in the event of a fire.

In addition to the above, TÜV SÜD's experts are also involved in the testing and approval processes for the hydrogen infrastructure, providing services such as inspection of the hydrogen filling systems. Regarding the expansion of the network of stationary hydrogen filling systems that are required for the operation of the rail vehicle, TÜV SÜD Rail is acting as moderator in the expert discussions between the various authorities to ensure compliance with the differing approaches of the authorities in the individual German states. TÜV SÜD also provides expert support to rail companies, infrastructure operators and maintenance companies, assisting them with their questions.

The project also covers workshops in which fire and rescue services will be familiarised with hydrogen technology and personnel trainings to ensure specialist technical qualifications.

Continuous testing and inspection during design and development and the associated confirmation that all safety-related requirements have been fulfilled provides the train manufacturer with a sound basis for future planning, also with respect to subsequent railway- and operation-specific changes of technical systems.

The collaboration between the various divisions and experts at TÜV SÜD resulted in significant synergy effects. TÜV SÜD was also able to provide integrated assessment of systems, an aspect which is more and more in demand. The project, in turn, enabled the experts to further grow their experience.

A special challenge in the project was the early acceptance management required for the use of tried-and-tested hydrogen technology in the new setting. Because the market for hydrogen applications will continue to grow, TÜV SÜD plans on building an even stronger and more networked team in this discipline.

If you have detailed questions on the project or on hydrogen technology, please do not hesitate to contact our experts:

Dr Jürgen Heyn, Fire-safety expert

Daniel Hielscher, Hydrogen-technology expert