Composite materials are increasingly being integrated into various industries such as aerospace for their cost and carbon footprint benefits. Today, they are an important part of the range of materials that engineers can select to develop new products and components. In the rail industry, after the advent of hydrogen trains, the use of composites in vehicle design also offers opportunities for decarbonization.

Towards the railway vehicle of tomorrow

Rail composites refer to various synthetic materials used to improve the flexibility and performance of trains. Some of the resins commonly used as rail composites include polyester, phenolic resin, epoxy and vinyl esters. With the significant growth in tourism, rail vehicle manufacturers are turning to energy-efficient, and therefore more cost-effective raw materials and contributing to the growth of the market. Due to the increasing demand for high-speed trains (HSR), rail composites are widely adopted to manufacture lightweight train components to minimize the overall structural weight. In addition, several innovations such as the development of biodegradable and sustainable substitutes to existing composites (natural fiber and resin-based variants) will continue to drive the composites market in the railway industry in the coming years.

For example, in the UK, TBR Lightweight Structures worked closely with consortium leader Transport Design International (TDI) on the design of the Revolution VLR (Very Light Rail), an innovative passenger vehicle that will simplify the extension of existing rail networks and re-open historic lines. The company designed the composite body of the train, manufacturing the one-piece modular structural panels that form the inner and outer walls. With innovative and durable materials, the Revolution VLR train was able to be 40% lighter than traditional heavy rail vehicles of similar capacity, with a 16 ton reduction in overall weight. The use of new composite materials also makes it easier to replace parts for general maintenance needs, which is key to the longevity of the vehicle, given its 30- to 40-year lifespan.

Benefits of using composites

The use of such materials provides better resistance to high temperatures, humidity, fire and corrosion than metal components. These materials also improve aesthetics and minimize energy consumption (and therefore costs), noise and vibration, which improves passenger comfort. Beyond lightness, which offers better performance thanks to an excellent strength/weight ratio, composite materials have additional properties and offer many advantages to meet the requirements of a very demanding use, such as freedom and flexibility of design making possible an infinite number of shapes, resistance to shock, chemical corrosion, rust and UV, rigidity, or the incorporation in the material of sensors, connectors, wiring and lights.

Finally, as part of a circular economy, composite manufacturing allows for the recycling of materials such as nylon recovered from end-of-life fishing nets, carbon fibers, or fully and partially recycled thermoplastic polyurethanes (TPU) used in protective smartphone shells.