The aviation industry has introduced even from its beginnings the most efficient and lightweight materials for aircraft construction; this industry is actively working to develop innovations in the field of light materials. The need for combining lighter materials with a resistant aircraft structure has brought on the market a range of innovative lightweight materials, which have quickly become attractive for the rail industry. In order to develop systems for high speed trains, which bring a need for new materials and building technologies, several companies started to develop materials by looking at the projects for the aviation industry. To this end, the REFRESCO project was launched and funded by the European Union.
The European project REFRESCO
Launched in September 2013, the project REFRESCO (REgulatory FRamework for the usE of Structural new materials in railway passenger and freight CarbOdyshells) was funded by the European Union for a period of 30 months, with a budget of € 4.6 million. The project aimed to achieve a legal framework for the certification of railway rolling stock built entirely of lightweight, non-metal materials and composites. A large part of the rolling stock that has been designed in the last 10 years includes components made of composite materials, but no train has yet been built entirely of non-metallic materials, especially because there is no legal framework for the authorization of new technologies that could ultimately lead to the certification of trains.
The REFRESCO project was based on the successful use of these materials in the aircraft industry, which leads to a slight assimilation and regulation for the railway section, where, in theory, the risks are lower than those in aviation. The materials that have been used for the wind power technologies have also been considered, and the project has involved companies from the industries using these materials on a large scale. For the certification of these materials in the railway industry, regulations are taking into account their maintenance, their structural resistance, fire and heat resistance and their energy efficiency. The project also aimed to collaborate with the SHIFT2RAIL program in order to increase railway safety and quality standards.
The project has successfully ended, concluding that trains can be built entirely of composite materials by introducing some special regulations. By using these materials the weight of the wagon will be reduced by 30%, thus providing high energy efficiency, and reducing CO2 emissions. The completion of the project only translated to compiling a set of regulations and a pilot project is scheduled to start for the construction of a train made of composite materials which will be tested in order to obtain a final certification of the new regulation. The set of guidelines includes efficiency studies for materials used in the aircraft and space industry, while the modifications brought to the railway industry with regards to using these materials has also been considered. Among the modifications are the necessity to re-qualify the maintenance staff, the emergence of new plants for this kind of components, being mentioned an average time period for large scale implementation of composite materials in the rail industry.
Developing the new concept at Newcastle University
The research center at the Newcastle University is currently investigating the development of new materials for the next generation of trains. The working context is the exploitation of the benefits of this kind of materials for the railways, while aviation companies, such as Boeing, have been working with these materials for over 30 years. For example, 50% of the Boeing 787 is made of composite materials. However, if compared to aircraft, trains have different characteristics that do not justify the use of expensive materials, like carbon fiber. To conclude, the most frequently used materials in the rail industry have remained the glass fiber and simple composite materials for aero-dynamic areas or train interiors.
The researchers have developed composite structures that would fit every application through systematic, optimized and strong decisions. Moreover, researchers are considering applying these kinds of materials on a medium term for the rail industry. In collaboration with Bombardier Transportation, a high-speed rail cabin has been developed based on a modular innovative design made of a single light piece. As opposed to conventional cabins made of structures of steel covered in glass fiber, this cabin is based on the concept of sandwich-structured composites. This innovative system provides functionality through a single advanced component, with reduced manufacturing and operational costs. Within the collaboration with Alstom and Bombardier, the researchers have developed a handrail model for metro trains. This handrail, made of light composite materials, is cheaper and lighter than the normal ones, made of metal.
Researchers at Newcastle University have also initiated the FIRE-RESIST project, with a duration of 4 years and with a budget of 7.8 million euros. This project brings collaboration between the rail, aircraft and maritime industries for the development of new solutions for composite materials that are resistant to high temperatures and fires. Lower resistance to these factors is one of the reasons for which the implementation of light composite materials on a large scale is avoided in the cases where it’s not strictly necessary. The project includes studies for increasing the performance of aluminum and light materials in case of fire. Materials used for finishes inside the train are especially taken into consideration. The researchers started developing several prototypes of fire safe materials, which do not release dangerous gases and do not affect the resistance structure of the rolling stock.
(Featured image: Airbus – airbus.com)